UFGI publication round-up week 9/25, 10/2, 10/9 and 10/16/17
Impeding Transcription of Expanded Microsatellite Repeats by Deactivated Cas9.
Abstract
Transcription of expanded microsatellite repeats is associated with multiple human diseases, including myotonic dystrophy, Fuchs endothelial corneal dystrophy, and C9orf72-ALS/FTD. Reducing production of RNA and proteins arising from these expanded loci holds therapeutic benefit. Here, we tested the hypothesis that deactivated Cas9 enzyme impedes transcription across expanded microsatellites. We observed a repeat length-, PAM-, and strand-dependent reduction of repeat-containing RNAs upon targeting dCas9 directly to repeat sequences; targeting the non-template strand was more effective. Aberrant splicing patterns were rescued in DM1 cells, and production of RAN peptides characteristic of DM1, DM2, and C9orf72-ALS/FTD cells was drastically decreased. Systemic delivery of dCas9/gRNA by adeno-associated virus led to reductions in pathological RNA foci, rescue of chloride channel 1 protein expression, and decreased myotonia. These observations suggest that transcription of microsatellite repeat-containing RNAs is more sensitive to perturbation than transcription of other RNAs, indicating potentially viable strategies for therapeutic intervention.
Association of the HLA-B alleles with carbamazepine-induced Stevens-Johnson syndrome/toxic epidermal necrolysis in the Javanese and Sundanese population of Indonesia: the important role of the HLA-B75 serotype.
Abstract
Carbamazepine (CBZ) is a common cause of life-threatening cutaneous adverse drug reactions such as Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Previous studies have reported a strong association between the HLA genotype and CBZ-induced SJS/TEN. We investigated the association between the HLA genotype and CBZ-induced SJS/TEN in Javanese and Sundanese patients in Indonesia. Nine unrelated patients with CBZ-induced SJS/TEN and 236 healthy Javanese and Sundanese controls were genotyped for HLA-B and their allele frequencies were compared. The HLA-B*15:02 allele was found in 66.7% of the patients with CBZ-induced SJS/TEN, but only in 29.4% of tolerant control (p = 0.029; odds ratio [OR]: 6.5; 95% CI: 1.2-33.57) and 22.9% of healthy controls (p = 0.0021; OR: 6.78; 95% CI: 1.96-23.38). These findings support the involvement of HLA-B*15:02 in CBZ-induced SJS/TEN reported in other Asian populations. Interestingly, we also observed the presence of the HLA-B*15:21 allele. HLA-B*15:02 and HLA-B*15:21 are members of the HLA-B75 serotype, for which a greater frequency was observed in CBZ-induced SJS/TEN (vs tolerant control [p = 0.0078; OR: 12; 95% CI: 1.90-75.72] and vs normal control [p = 0.0018; OR: 8.56; 95% CI: 1.83-40]). Our findings suggest that screening for the HLA-B75 serotype can predict the risk of CBZ-induced SJS/TEN more accurately than screening for a specific allele.
Transient BAFF Blockade Inhibits Type 1 Diabetes Development in Nonobese Diabetic Mice by Enriching Immunoregulatory B Lymphocytes Sensitive to Deletion by Anti-CD20 Cotherapy.
Abstract
In NOD mice and also likely humans, B lymphocytes play an important role as APC-expanding autoreactive T cell responses ultimately causing type 1 diabetes (T1D). Currently, humans at high future T1D risk can only be identified at late prodromal stages of disease indicated by markers such as insulin autoantibodies. When commenced in already insulin autoantibody+ NOD mice, continuous BAFFR-Fc treatment alone or in combination with anti-CD20 (designated combo therapy) inhibited T1D development. Despite eliciting broader B lymphocyte depletion, continuous combo therapy afforded no greater T1D protection than did BAFFR-Fc alone. As previously observed, late disease stage-initiated anti-CD20 monotherapy did not inhibit T1D, and in this study was additionally found to be associated with development of drug-blocking Abs. Promisingly, NOD mice given transient late disease stage BAFFR-Fc monotherapy were rendered T1D resistant. However, combo treatment abrogated the protective effect of transient BAFFR-Fc monotherapy. NOD mice receiving transient BAFF blockade were characterized by an enrichment of regulatory B lymphocytes that inhibit T1D development through IL-10 production, but this population is sensitive to deletion by anti-CD20 treatment. B lymphocytes from transient BAFFR-Fc-treated mice suppressed T cell proliferation to a greater extent than did those from controls. Proportions of B lymphocytes expressing CD73, an ecto-enzyme operating in a pathway converting proinflammatory ATP to anti-inflammatory adenosine, were also temporarily increased by transient BAFFR-Fc treatment, but not anti-CD20 therapy. These collective studies indicate transient BAFFR-Fc-mediated B lymphocyte depletion elicits long-term T1D protection by enriching regulatory B lymphocytes that are deleted by anti-CD20 cotherapy.
Association Between Early-Life Antibiotic Use and the Risk of Islet or Celiac Disease Autoimmunity.
Abstract
IMPORTANCE:
Evidence is lacking regarding the consequences of antibiotic use in early life and the risk of certain autoimmune diseases.
OBJECTIVE:
To test the association between early-life antibiotic use and islet or celiac disease (CD) autoimmunity in genetically at-risk children prospectively followed up for type 1 diabetes (T1D) or CD.
DESIGN, SETTING, AND PARTICIPANTS:
HLA-genotyped newborns from Finland, Germany, Sweden, and the United States were enrolled in the prospective birth cohort of The Environmental Determinants of Diabetes in the Young (TEDDY) study between November 20, 2004, and July 8, 2010. The dates of analysis were November 20, 2004, to August 31, 2014. Individuals from the general population and those having a first-degree relative with T1D were enrolled if they had 1 of 9 HLA genotypes associated with a risk for T1D.
EXPOSURES:
Parental reports of the most common antibiotics (cephalosporins, penicillins, and macrolides) used between age 3 months and age 4 years were recorded prospectively.
MAIN OUTCOMES AND MEASURES:
Islet autoimmunity and CD autoimmunity were defined as being positive for islet or tissue transglutaminase autoantibodies at 2 consecutive clinic visits at least 3 months apart. Hazard ratios and 95% CIs calculated from Cox proportional hazards regression models were used to assess the relationship between antibiotic use in early life before seroconversion and the development of autoimmunity.
RESULTS:
Participants were 8495 children (49.0% female) and 6558 children (48.7% female) enrolled in the TEDDY study who were tested for islet and tissue transglutaminase autoantibodies, respectively. Exposure to and frequency of use of any antibiotic assessed in this study in early life or before seroconversion did not influence the risk of developing islet autoimmunity or CD autoimmunity. Cumulative use of any antibiotic during the first 4 years of life was not associated with the appearance of any autoantibody (hazard ratio [HR], 0.98; 95% CI, 0.95-1.01), multiple islet autoantibodies (HR, 0.99; 95% CI, 0.95-1.03), or the transglutaminase autoantibody (HR, 1.00; 95% CI, 0.98-1.02).
CONCLUSIONS AND RELEVANCE:
The use of the most prescribed antibiotics during the first 4 years of life, regardless of geographic region, was not associated with the development of autoimmunity for T1D or CD. These results suggest that a risk of islet or tissue transglutaminase autoimmunity need not influence the recommendations for clinical use of antibiotics in young children at risk for T1D or CD.
UTX/KDM6A Loss Enhances the Malignant Phenotype of Multiple Myeloma and Sensitizes Cells to EZH2 inhibition.
Abstract
Loss or inactivation of the histone H3K27 demethylase UTX occurs in several malignancies, including multiple myeloma (MM). Using an isogenic cell system, we found that loss of UTX leads to deactivation of gene expression ultimately promoting the proliferation, clonogenicity, adhesion, and tumorigenicity of MM cells. Moreover, UTX mutant cells showed increased in vitro and in vivo sensitivity to inhibition of EZH2, a histone methyltransferase that generates H3K27me3. Such sensitivity was related to a decrease in the levels of IRF4 and c-MYC and an activation of repressors of IRF4 characteristic of germinal center B cells such as BCL6 and IRF1. Rebalance of H3K27me3 levels at specific genes through EZH2 inhibitors may be a therapeutic strategy in MM cases harboring UTX mutations.
An interview with Katrin Hinrichs.
Author information
Anti-inflammaging effects of human alpha-1 antitrypsin.
Abstract
Inflammaging plays an important role in most age-related diseases. However, the mechanism of inflammaging is largely unknown, and therapeutic control of inflammaging is challenging. Human alpha-1 antitrypsin (hAAT) has immune-regulatory, anti-inflammatory, and cytoprotective properties as demonstrated in several disease models including type 1 diabetes, arthritis, lupus, osteoporosis, and stroke. To test the potential anti-inflammaging effect of hAAT, we generated transgenic Drosophila lines expressing hAAT. Surprisingly, the lifespan of hAAT-expressing lines was significantly longer than that of genetically matched controls. To understand the mechanism underlying the anti-aging effect of hAAT, we monitored the expression of aging-associated genes and found that aging-induced expressions of Relish (NF-ĸB orthologue) and Diptericin were significantly lower in hAAT lines than in control lines. RNA-seq analysis revealed that innate immunity genes regulated by NF-kB were significantly and specifically inhibited in hAAT transgenic Drosophila lines. To confirm this anti-inflammaging effect in human cells, we treated X-ray-induced senescence cells with hAAT and showed that hAAT treatment significantly decreased the expression and maturation of IL-6 and IL-8, two major factors of senescence-associated secretory phenotype. Consistent with results from Drosophila,RNA-seq analysis also showed that hAAT treatment significantly inhibited inflammation related genes and pathways. Together, our results demonstrated that hAAT significantly inhibited inflammaging in both Drosophila and human cell models. As hAAT is a FDA-approved drug with a confirmed safety profile, this novel therapeutic potential may make hAAT a promising candidate to combat aging and aging-related diseases.
Elevated ozone reduces photosynthetic carbon gain by accelerating leaf senescence of inbred and hybrid maize in a genotype-specific manner.
Abstract
Exposure to elevated tropospheric ozone concentration ([O3 ]) accelerates leaf senescence in many C3 crops. However, the effects of elevated [O3 ] on C4 crops including maize (Zea mays L.) are poorly understood in terms of physiological mechanism and genetic variation in sensitivity. Using free air gas concentration enrichment, we investigated the photosynthetic response of 18 diverse maize inbred and hybrid lines to season-long exposure to elevated [O3 ] (~100 nl L-1 ) in the field. Gas exchange was measured on the leaf subtending the ear throughout the grain filling period. On average over the lifetime of the leaf, elevated [O3 ] led to reductions in photosynthetic CO2 assimilation of both inbred (-22%) and hybrid (-33%) genotypes. There was significant variation among both inbred and hybrid lines in the sensitivity of photosynthesis to elevated [O3 ], with some lines showing no change in photosynthesis at elevated [O3 ]. Based on analysis of inbred line B73, the reduced CO2 assimilation at elevated [O3 ] was associated with accelerated senescence decreasing photosynthetic capacity and not altered stomatal limitation. These findings across diverse maize genotypes could advance the development of more O3 tolerant maize and provide experimental data for parameterization and validation of studies modeling how O3 impacts crop performance.
Modeling and Preventing Progressive Hearing Loss in Usher Syndrome III.
Abstract
Usher syndrome type III (USH3) characterized by progressive loss of vision and hearing is caused by mutations in the clarin-1 gene (CLRN1). Clrn1 knockout (KO) mice develop hair cell defects by postnatal day 2 (P2) and are deaf by P21-P25. Early onset profound hearing loss in KO mice and lack of information about the cochlear cell type that requires Clrn1 expression pose challenges to therapeutic investigation. We generated KO mice harboring a transgene, TgAC1, consisting of Clrn1-UTR (Clrn1 cDNA including its 5′ and 3′ UTR) under the control of regulatory elements (Atoh1 3′ enhancer/β-globin basal promoter) to direct expression of Clrn1 in hair cells during development and down regulate it postnatally. The KO-TgAC1 mice displayed delayed onset progressive hearing loss associated with deterioration of the hair bundle structure, leading to the hypothesis that hair cell expression of Clrn1 is essential for postnatal preservation of hair cell structure and hearing. Consistent with that hypothesis, perinatal transfection of hair cells in KO-TgAC1 mice with a single injection of AAV-Clrn1-UTR vector showed correlative preservation of the hair bundle structure and hearing through adult life. Further, the efficacy of AAV-Clrn1 vector was significantly attenuated, revealing the potential importance of UTR in gene therapy.
Integrating evolutionary and regulatory information with a multispecies approach implicates genes and pathways in obsessive-compulsive disorder.
Abstract
Obsessive-compulsive disorder is a severe psychiatric disorder linked to abnormalities in glutamate signaling and the cortico-striatal circuit. We sequenced coding and regulatory elements for 608 genes potentially involved in obsessive-compulsive disorder in human, dog, and mouse. Using a new method that prioritizes likely functional variants, we compared 592 cases to 560 controls and found four strongly associated genes, validated in a larger cohort. NRXN1 and HTR2A are enriched for coding variants altering postsynaptic protein-binding domains. CTTNBP2 (synapse maintenance) and REEP3 (vesicle trafficking) are enriched for regulatory variants, of which at least six (35%) alter transcription factor-DNA binding in neuroblastoma cells. NRXN1 achieves genome-wide significance (p = 6.37 × 10-11) when we include 33,370 population-matched controls. Our findings suggest synaptic adhesion as a key component in compulsive behaviors, and show that targeted sequencing plus functional annotation can identify potentially causative variants, even when genomic data are limited.Obsessive-compulsive disorder (OCD) is a neuropsychiatric disorder with symptoms including intrusive thoughts and time-consuming repetitive behaviors. Here Noh and colleagues identify genes enriched for functional variants associated with increased risk of OCD.
Recommendations for Laboratory Containment and Management of Gene Drive Systems in Arthropods.
Abstract
Versatile molecular tools for creating driving transgenes and other invasive genetic factors present regulatory, ethical, and environmental challenges that should be addressed to ensure their safe use. In this article, we discuss driving transgenes and invasive genetic factors that can potentially spread after their introduction into a small proportion of individuals in a population. The potential of invasive genetic factors to increase their number in natural populations presents challenges that require additional safety measures not provided by previous recommendations regarding accidental release of arthropods. In addition to providing physical containment, invasive genetic factors require greater attention to strain management, including their distribution and identity confirmation. In this study, we focus on insects containing such factors with recommendations for investigators who are creating them, institutional biosafety committees charged with ensuring safety, funding agencies providing support, those managing insectaries handling these materials who are responsible for containment, and other persons who will be receiving insects-transgenic or not-from these facilities. We give specific examples of efforts to modify mosquitoes for mosquito-borne disease control, but similar considerations are relevant to other arthropods that are important to human health, the environment, and agriculture.
Environmental toxicology and omics: A question of sex.
Abstract
Molecular initiating events and downstream transcriptional/proteomic responses provide valuable information for adverse outcome pathways, which can be used predict the effects of chemicals on physiological systems. There has been a paucity of research that addresses sex-specific expression profiling in toxicology and due to cost, time, and logistical considerations, sex as a variable has not been widely considered. In response to this deficiency, federal agencies in the United States, Canada, and Europe have highlighted the importance of including sex as a variable in scientific investigations. Using case studies from both aquatic and mammalian toxicology, we report that there can be less than ~20-25% consensus in how the transcriptome and proteome of each sex responds to chemicals. Chemicals that have been shown to elicit sex-specific responses in the transcriptome or proteome include pharmaceuticals, anti-fouling agents, anticorrosive agents, and fungicides, among others. Sex-specific responses in the transcriptome and proteome are not isolated to whole animals, as investigations demonstrate that primary cell cultures isolated from each sex responds differently to toxicants. This signifies that sex is important, even in cell lines. Sex has significant implications for predictive toxicology, and both male and female data are required to improve robustness of adverse outcome pathways.
BIOLOGICAL SIGNIFICANCE:
Clinical toxicology recognizes that sex is an important variable, as pharmacokinetics (ADME; absorption, distribution, metabolism, and excretion) can differ between females and males. However, few studies in toxicology have explored the implication of sex in relation to the transcriptome and proteome of whole organisms. High-throughput molecular approaches are becoming more frequently applied in toxicity screens (e.g. pre-clinical experiments, fish embryos, cell lines, synthetic tissues) and such data are expected to build upon reporter-based cell assays (e.g. receptor activation, enzyme inhibition) used in toxicant screening programs (i.e. Tox21, ToxCast, REACH). Thus, computational models can more accurately predict the diversity of adverse effects that can occur from chemical exposure within the biological system. Our studies and those synthesized from the literature suggest that the transcriptome and proteome of females and males respond quite differently to chemicals. This has significant implications for predicting adverse effects in one sex when using molecular data generated in the other sex. While molecular initiating events are not expected to differ dramatically between females and males (i.e. an estrogen binds estrogen receptors in both sexes), it is important to acknowledge that the downstream transcriptomic and proteomic responses can differ based upon the presence/absence of co-regulators and inherent sex-specific variability in regulation of transcriptional and translational machinery. Transcriptomic and proteomic studies also reveal that cell processes affected by chemicals can differ due to sex, and this can undoubtedly lead to sex-specific physiological responses.
Extracellular Pyridine Nucleotides as Immune Elicitors in Arabidopsis.
Abstract
The pyridine nucleotides nicotinamide adenine dinucleotide (NAD) and NAD phosphate (NADP) are coenzymes that function in both metabolic reactions and intracellular signaling. Emerging evidence from animal research indicates that NAD(P) also acts in the extracellular space (ECS). We have shown in the model plant Arabidopsis that (1) exogenous NAD(P) induces immune responses, (2) pathogen infection causes leakage of intracellular NAD(P) into the extracellular fluid at concentrations sufficient to induce immune responses, and (3) removal of extracellular NAD(P) [eNAD(P)] by expressing the human NAD(P)-metabolizing ectoenzyme CD38 partially compromises systemic acquired resistance. Based on these results, we hypothesize that eNAD(P) is a novel damage-associated molecular pattern (DAMP) in plants; during plant-microbe interaction, intracellular NAD(P) is released from dead or dying cells into the ECS where it interacts with the adjacent healthy cells’ surface receptors/targets, which in turn activate downstream specific immune signaling pathways. Our recent identification of LecRK-I.8, a lectin receptor kinase, as the first cell surface NAD+-binding receptor has provided compelling evidence for this hypothesis. Further identification of cell surface eNAD(P) receptors/targets and their downstream signaling components in Arabidopsis as well as determination of the generality of eNAD(P) signaling in crops will help establish eNAD(P) as a conserved DAMP in plants.
Intergenerational environmental effects: functional signals in offspring transcriptomes and metabolomes after parental jasmonic acid treatment in apomictic dandelion.
Abstract
Parental environments can influence offspring traits. However, the magnitude of the impact of parental environments on offspring molecular phenotypes is poorly understood. Here, we test the direct effects and intergenerational effects of jasmonic acid (JA) treatment, which is involved in herbivory-induced defense signaling, on transcriptomes and metabolomes in apomictic common dandelion (Taraxacum officinale). In a full factorial crossed design with parental and offspring JA and control treatments, we performed leaf RNA-seq gene expression analysis, LC-MS metabolomics and total phenolics assays in offspring plants. Expression analysis, leveraged by a de novo assembled transcriptome, revealed an induced response to JA exposure that is consistent with known JA effects. The intergenerational effect of treatment was considerable: 307 of 858 detected JA-responsive transcripts were affected by parental JA treatment. In terms of the numbers of metabolites affected, the magnitude of the chemical response to parental JA exposure was c. 10% of the direct JA treatment response. Transcriptome and metabolome analyses both identified the phosphatidylinositol signaling pathway as a target of intergenerational JA effects. Our results highlight that parental environments can have substantial effects in offspring generations. Transcriptome and metabolome assays provide a basis for zooming in on the potential mechanisms of inherited JA effects.
Dermal pharmacokinetics of pyrazinamide determined by microdialysis sampling in rats.
Abstract
Studies have demonstrated pyrazinamide’s efficacy against stages of the parasite which causes cutaneous leishmaniasis. Although pyrazinamide is widely distributed to most fluids and tissues, the drug distribution that reaches the skin is unknown. The aim of this study was to investigate pyrazinamide pharmacokinetics in rat dermal tissue by dermal microdialysis. Skin pharmacokinetics were assessed by implanting a linear microdialysis probe in the dermis of ten rats. Additionally, blood samples were collected for assessing plasma pharmacokinetics. Unbound microdialysate samples (N = 280) and plasma (N = 120) concentrations after single intravenous doses of 25 or 50 mg/kg pyrazinamide were quantified by a validated HPLC method. Probe calibration was performed by retrodialysis. A non-compartmental analysis and non-linear mixed-effect modeling were performed using WinNonlin and NONMEM version 7.3. Pyrazinamide rapidly permeated into the dermis and reached high levels with an average maximum concentration (Cmax) of 22.4 ± 7.1 and 48.6 ± 17.3 µg/ml for the doses studied. Levels of pyrazinamide showed a significant distribution to the skin (fAUCdermal/fAUCplasma = 0.82 ± 0.3 and 0.84 ± 0.2) for 25 and 50 mg/kg, respectively. Active unbound concentrations in dermal tissue reached lower levels than free plasma concentrations, indicating that the free pyrazinamide levels in plasma were in equilibrium with the tissue levels. These results showed equivalent unbound drug tissue concentrations and corresponding unbound plasma levels. In conclusion, this study shows that PZA distributes rapidly into dermal interstitial fluid space in rats and therefore may be a potential agent in the treatment of cutaneous leishmaniasis.
DNA methylation of methylation complex genes in relation to stress and genome-wide methylation in mother-newborn dyads.
Abstract
OBJECTIVES:
Early life stress is known to have enduring biological effects, particularly with respect to health. Epigenetic modifications, such as DNA methylation, are a possible mechanism to mediate the biological effect of stress. We previously found correlations between maternal stress, newborn birthweight, and genome-wide measures of DNA methylation. Here we investigate ten genes related to the methylation/demethylation complex in order to better understand the impact of stress on health.
MATERIALS AND METHODS:
DNA methylation and genetic variants at methylation/demethylation genes were assayed. Mean methylation measures were constructed for each gene and tested, in addition to genetic variants, for association with maternal stress measures based on interview and survey data (chronic stress and war trauma), maternal venous, and newborn cord genome-wide mean methylation (GMM), and birthweight.
RESULTS:
After cell type correction, we found multiple pairwise associations between war trauma, maternal GMM, maternal methylation at DNMT1, DNMT3A, TET3, and MBD2, and birthweight.
CONCLUSIONS:
The association of maternal GMM and maternal methylation at DNMT1, DNMT3A, TET3, and MBD2 is consistent with the role of these genes in establishing, maintaining and altering genome-wide methylation patterns, in some cases in response to stress. DNMT1 produces one of the primary enzymes that reproduces methylation patterns during DNA replication. DNMT3A and TET3 have been implicated in genome-wide hypomethylation in response to glucocorticoid hormones. Although we cannot determine the directionality of the genic and genome-wide changes in methylation, our results suggest that altered methylation of specific methylation genes may be part of the molecular mechanism underlying the human biological response to stress.
Disease-specific biases in alternative splicing and tissue-specific dysregulation revealed by multitissue profiling of lymphocyte gene expression in type 1 diabetes.
Abstract
Genome-wide association studies (GWAS) have identified multiple, shared allelic associations with many autoimmune diseases. However, the pathogenic contributions of variants residing in risk loci remain unresolved. The location of the majority of shared disease-associated variants in noncoding regions suggests they contribute to risk of autoimmunity through effects on gene expression in the immune system. In the current study, we test this hypothesis by applying RNA sequencing to CD4+, CD8+, and CD19+ lymphocyte populations isolated from 81 subjects with type 1 diabetes (T1D). We characterize and compare the expression patterns across these cell types for three gene sets: all genes, the set of genes implicated in autoimmune disease risk by GWAS, and the subset of these genes specifically implicated in T1D. We performed RNA sequencing and aligned the reads to both the human reference genome and a catalog of all possible splicing events developed from the genome, thereby providing a comprehensive evaluation of the roles of gene expression and alternative splicing (AS) in autoimmunity. Autoimmune candidate genes displayed greater expression specificity in the three lymphocyte populations relative to other genes, with significantly increased levels of splicing events, particularly those predicted to have substantial effects on protein isoform structure and function (e.g., intron retention, exon skipping). The majority of single-nucleotide polymorphisms within T1D-associated loci were also associated with one or more cis-expression quantitative trait loci (cis-eQTLs) and/or splicing eQTLs. Our findings highlight a substantial, and previously underrecognized, role for AS in the pathogenesis of autoimmune disorders and particularly for T1D.
Locomotor and skeletal muscle abnormalities in trembler J neuropathic mice.
Abstract
INTRODUCTION:
Patients with hereditary peripheral neuropathies exhibit characteristic deformities of the hands and feet and have difficulty ambulating. To examine to what extent neuropathic animals recapitulate these deficits, we studied trembler J (TrJ) mice, which model early-onset demyelinating neuropathy.
METHODS:
A cohort of 4-month-old female wild type and neuropathic mice were evaluated for locomotor measurements, neuromuscular function, and skeletal muscle proteolysis and morphometry.
RESULTS:
Utilizing the DigiGait imaging system, we identified pronounced alterations in forepaw and hindpaw angles and a decrease in hindpaw area on the treadmill in neuropathic rodents. Torque production by the tibialis anterior (TA) muscle was significantly weakened and was paralleled by a decrease in myofiber cross-sectional area and an increase in muscle tissue proteolysis.
DISCUSSION:
Our findings in TrJ mice reflect the phenotypic presentation of the human neuropathy in which patients exhibit weakness of the TA muscle resulting in foot drop and locomotor abnormalities. Muscle Nerve, 2017.
Unanticipated Cardiotoxicity Associated with Targeted Anticancer Therapy in Patients with Hematologic Malignancies Patients: Natural History and Risk Factors.
Abstract
Our aim is to study unanticipated cardiotoxicity associated with the use of anticancer targeted agents, a problem that remains poorly understood. Using diagnosis codes, we retrospectively identified patients with both hematologic malignancies (HM) and cardiovascular diseases (n = 820 patients). Cardiotoxicity was defined per published criteria. The targeted agents of interest included tyrosine kinase inhibitors, proteasome inhibitors, monoclonal antibodies, and immunomodulatory agents. Patients found with cardiotoxicity (n = 29) were compared with 70 case-matched reference subjects. Median time from targeted therapy exposure to cardiotoxicity was 132 days. A higher percentage of patients had prior exposure to anthracyclines in study versus reference group (65.5 vs. 42.8%, P = 0.04), however, did not stay significant in multivariate analysis. Two variables were significant predictors, prior of DVT/PE and Karnofsky score of ≥ 80% (P ≤ 0.011). Only 2 study group patients died of cardiac causes. Most cardiotoxicity patients (23/29) had remained stable or improved, while 21 patients received further chemotherapy. OS was lower in the study group (P = 0.018) versus the reference group. In conclusion, a small number patients with HM experience unanticipated cardiotoxicity with low related mortality. Risk of cardiotoxicity was significantly associated with history of DVT/PE. Most patients do well, but despite that, their OS is significantly poorer.
Safety and Efficacy of AAV5 Vectors Expressing Human or Canine CNGB3 in CNGB3-mutant Dogs.
Abstract
Achromatopsia is an inherited retinal disorder of cone photoreceptors characterized by markedly reduced visual acuity, extreme light sensitivity and absence of color discrimination. Approximately 50% of cases are caused by mutations in the cone photoreceptor-specific cyclic nucleotide gated channel beta subunit (CNGB3) gene. Studies in CNGB3-mutant dogs showed that subretinal injection of an AAV vector expressing human CNGB3, which has 76% amino acid identity with canine CNGB3, driven by a 2.1 kb human red cone opsin promoter (PR2.1) and packaged in AAV5 capsids (AAV5-PR2.1-hCNGB3) rescued cone photoreceptor function, but at high doses was associated with an inflammatory response (focal chorioretinitis) consistent with immune-mediated toxicity. AAV vectors containing the PR2.1 promoter packaged in AAV5 capsids and expressing either the native canine CNGB3 (AAV5-PR2.1-cCNGB3) or the human CNGB3 (AAV5-PR2.1-hCNGB3) were evaluated at different dose levels in CNGB3-mutant dogs. The vector expressing canine CNGB3 achieved somewhat better rescue of cone function but unexpectedly was associated with a greater degree of retinal toxicity than the vector expressing human CNGB3. Very low level T cell immune responses to some AAV or CNGB3 peptides were observed in animals that received the higher vector dose. There was a >2-fold increase in serum neutralizing antibodies to AAV in 1 of 3 animals in the low dose group and 2 of 3 animals in the high dose group. No serum anti-hCNGB3 antibodies were detected in any animal. Results of this study do not support the hypothesis that the focal chorioretinitis seen with high doses of AAV5-PR2.1-hCNGB3 in the initial studies was due to an immune response to human CNGB3.
Associations between maternal prenatal stress, methylation changes in IGF1 and IGF2, and birth weight.
Abstract
Maternal stress has been linked to low birth weight in newborns. One potential pathway involves epigenetic changes at candidate genes that may mediate the effects of prenatal maternal stress on birth weight. This relationship has been documented in stress-related genes, such as NR3C1. There is less literature exploring the effect of stress on growth-related genes. IGF1 and IGF2 have been implicated in fetal growth and development, though via different mechanisms as IGF2 is under imprinting control. In this study, we tested for associations between prenatal stress, methylation of IGF1 and IGF2, and birth weight. A total of 24 mother-newborn dyads in the Democratic Republic of Congo were enrolled. Ethnographic interviews were conducted with mothers at delivery to gather culturally relevant war-related and chronic stressors. DNA methylation data were generated from maternal venous, cord blood and placental tissue samples. Multivariate regressions were used to test for associations between stress measures, DNA methylation and birth weight in each of the three tissue types. We found an association between IGF2 methylation in maternal blood and birth weight. Previous literature on the relationship between IGF2 methylation and birth weight has focused on methylation at known differentially methylated regions in cord blood or placental samples. Our findings indicate there may be links between the maternal epigenome and low birth weight that rely on mechanisms outside known imprinting pathways. It thus may be important to consider the effect of maternal exposures and epigenetic profiles on birth weight even in the setting of maternally imprinted genes such as IGF2.
Ctenophore relationships and their placement as the sister group to all other animals.
Abstract
Ctenophora, comprising approximately 200 described species, is an important lineage for understanding metazoan evolution and is of great ecological and economic importance. Ctenophore diversity includes species with unique colloblasts used for prey capture, smooth and striated muscles, benthic and pelagic lifestyles, and locomotion with ciliated paddles or muscular propulsion. However, the ancestral states of traits are debated and relationships among many lineages are unresolved. Here, using 27 newly sequenced ctenophore transcriptomes, publicly available data and methods to control systematic error, we establish the placement of Ctenophora as the sister group to all other animals and refine the phylogenetic relationships within ctenophores. Molecular clock analyses suggest modern ctenophore diversity originated approximately 350 million years ago ± 88 million years, conflicting with previous hypotheses, which suggest it originated approximately 65 million years ago. We recover Euplokamis dunlapae-a species with striated muscles-as the sister lineage to other sampled ctenophores. Ancestral state reconstruction shows that the most recent common ancestor of extant ctenophores was pelagic, possessed tentacles, was bioluminescent and did not have separate sexes. Our results imply at least two transitions from a pelagic to benthic lifestyle within Ctenophora, suggesting that such transitions were more common in animal diversification than previously thought.
Transcription factor CitERF71 activates the terpene synthase gene CitTPS16 involved in the synthesis of E-geraniol in sweet orange fruit.
Abstract
The unique flavor of Citrus fruit depends on complex combinations of soluble sugars, organic acids, and volatile compounds. The monoterpene E-geraniol is an important volatile, contributing to flavor in sweet orange (Citrus sinensis Osbeck). Moreover, antifungal activity of E-geraniol has also been observed. However, the terpene synthase (TPS) responsible for its synthesis has not been identified in sweet orange. Terpene synthase 16 (CitTPS16) was shown to catalyze synthesis of E-geraniol in vitro, and transient overexpression of CitTPS16 in fruits and leaves of Newhall sweet orange resulted in E-geraniol accumulation in vivo. Having identified the responsible enzyme, we next examined transcriptional regulation of CitTPS16 in the fruit. Among cloned members of the AP2/ERF transcription factor gene family, CitERF71 showed a similar expression pattern to CitTPS16. Moreover, CitERF71 was able to activate the CitTPS16 promoter based on results from transient dual-luciferase assays and yeast one-hybrid assays. EMSAs showed that CitERF71 directly binds to ACCCGCC and GGCGGG motifs in the CitTPS16 promoter. These results indicate an important role for CitERF71 in transcriptional regulation of CitTP16 and, therefore, in controlling production of E-geraniol in Citrus fruit.
Advanced Copper Composites against Copper-Tolerant Xanthomonas perforans and Tomato Bacterial Spot.
Abstract
Bacterial spot, Xanthomonas spp., is a widespread and damaging bacterial disease of tomatoes (Solanum lycopersicum). For disease management, growers rely on copper bactericides, which are often ineffective due to the presence of copper-tolerant Xanthomonas strains. This study evaluated the antibacterial activity of the new copper composites core-shell copper (CS-Cu), multi-valent copper (MV-Cu), and fixed quaternary ammonium copper (FQ-Cu) as potential alternatives to commercially available micron-sized copper bactericides for controlling copper-tolerant X. perforans. In vitro, 100 μg/ml of metallic copper from CS-Cu and FQ-Cu killed the copper-tolerant X. perforans strain within 1 h of exposure. In contrast, none of the micron-sized copper rates (100-1000 μg/ml) from Kocide® 3000 significantly reduced copper-tolerant X. perforans populations after 48 h of exposure compared to the water control (P< 0.05). All copper-based treatments killed the copper-sensitive X. perforans strain within 1 h. Greenhouse studies demonstrated that all copper composites significantly reduced bacterial spot disease severity when compared to copper-mancozeb and water controls (P< 0.05). Although there was no significant impact on yield, copper composites significantly reduced disease severity when compared to water controls using 80% less metallic copper in comparison to copper-mancozeb in field studies (P< 0.05). This study highlights that copper composites have the potential to manage copper-tolerant X. perforans and tomato bacterial spot.
A bifunctional catalase-peroxidase, MakatG1, contributes to virulence of Metarhizium acridum by overcoming oxidative stress on the host insect cuticle.
Abstract
Microbial pathogens are exposed to damaging reactive oxygen species (ROS) produced from a variety of sources including chemical reactions due to exposure to stress (UV, heat) or by hosts as a defense response. Here, we demonstrate that a bifunctional catalase-peroxidase, MakatG1, in the locust-specific fungal pathogen, Metarhizium acridum, functions as a ROS detoxification mechanism during host cuticle penetration. MakatG1 expression was highly induced during on-cuticle appressoria development as compared to vegetative (mycelia) growth or during in vivo growth in the insect hemocoel. A MakatG1 deletion mutant strain (ΔMakatG1) showed decreased catalase and peroxidase activities and significantly increased susceptibility to oxidative (H2 O2 and menadione) and UV stress as compared to wild-type and complemented strains. Insect bioassays revealed significantly reduced virulence of the ΔMakatG1 mutant when topically inoculated, but no impairment when the insect cuticle was bypassed. Germination and appressoria formation rates for the ΔMakatG1 mutant were decreased on locust wings and quinone/phenolic compounds derived from locust wings, but were not affected on plastic surfaces compared with the wild-type strain. These data indicate that MakatG1 plays a pivotal role in penetration, reacting to and detoxifying specific cuticular compounds present on the host cuticle during the early stages of fungal infection.
Overexpression of DEMETER, a DNA demethylase, promotes early apical bud maturation in poplar.
Abstract
The transition from active growth to dormancy is critical for the survival of perennial plants. We identified a DEMETER-like (CsDML) cDNA from a winter-enriched cDNA subtractive library in chestnut (Castanea sativa Mill.), an economically and ecologically important species. Next, we characterized this DNA demethylase and its putative ortholog in the more experimentally tractable hybrid poplar (Populus tremula × alba), under the signals that trigger bud dormancy in trees. We performed phylogenetic and protein sequence analysis, gene expression profiling, and 5-methyl-cytosine methylation immunodetection studies to evaluate the role of CsDML and its homolog in poplar, PtaDML6. Transgenic hybrid poplars overexpressing CsDML were produced and analysed. Short days and cold temperatures induced CsDML and PtaDML6. Overexpression of CsDML accelerated short-day-induced bud formation, specifically from Stages 1 to 0. Buds acquired a red-brown coloration earlier than wild-type plants, alongside with the up-regulation of flavonoid biosynthesis enzymes and accumulation of flavonoids in the shoot apical meristem and bud scales. Our data show that the CsDML gene induces bud formation needed for the survival of the apical meristem under the harsh conditions of winter.
Role of genetic testing in patients undergoing percutaneous coronary intervention.
Abstract
INTRODUCTION:
Variability in individual response profiles to antiplatelet therapy, in particular clopidogrel, is a well-established phenomenon. Genetic variations of the cytochrome P450 (CYP) 2C19 enzyme, a key determinant in clopidogrel metabolism, have been associated with clopidogrel response profiles. Moreover, the presence of a CYP2C19 loss-of-function allele is associated with an increased risk of atherothrombotic events among clopidogrel-treated patients undergoing percutaneous coronary interventions (PCI), prompting studies evaluating the use of genetic tests to identify patients who may be potential candidates for alternative platelet P2Y12receptor inhibiting therapies (prasugrel or ticagrelor). Areas covered: The present manuscript provides an overview of genetic factors associated with response profiles to platelet P2Y12 receptor inhibitors and their clinical implications, as well as the most recent developments and future considerations on the role of genetic testing in patients undergoing PCI. Expert commentary: The availability of more user-friendly genetic tests has contributed towards the development of many ongoing clinical trials and personalized medicine programs for patients undergoing PCI. Results of pilot investigations have shown promising results, which however need to be confirmed in larger-scale studies to support the routine use of genetic testing as a strategy to personalize antiplatelet therapy and improve clinical outcomes.
Agreement between self-reported and register-based cardiovascular events among Danish breast cancer survivors.
Abstract
PURPOSE:
We examined the degree of over- and under-reporting of cardiovascular diseases (CVDs) among female breast cancer survivors comparing self-reports to diagnostic codes from the Danish National Patient Register (NPR).
METHODS:
The study comprised 357 Danish breast cancer patients from the WECARE study who completed a telephone interview concerning CVDs. Disease diagnoses for these women were obtained from the NPR. Agreement was calculated as the number of diagnoses that were both self-reported and in the NPR divided by (1) number of self-reported diagnoses (over-reporting) or (2) number of diagnoses in the NPR (under-reporting).
RESULTS:
In total, 68 women reported 96 specific cardiovascular outcomes of which 56 (58%) were found in the NPR. Ninety cardiovascular diagnoses were found in the NPR of which 56 (62%) were specifically reported at the interview. There was 80% agreement as to the occurrence of a cardiovascular diagnosis overall. Of 289 women reporting no CVD, 273 (94%) had no diagnoses in the NPR.
CONCLUSIONS:
Breast cancer survivors seem to report absence of CVD accurately, but they both over-report and under-report specific cardiovascular diagnoses. Using a broader definition of CVDs improves the agreement between self-reported and NPR data.
IMPLICATIONS FOR CANCER SURVIVORS:
Determining how cancer treatments affect the risk of cardiovascular morbidities is essential, and the development of high-quality methods for collecting such data is critical. While self-reported data are adequate for assessing the presence of any CVD condition, medical record review will yield higher quality data on specific CVD conditions.
The Good That Viruses Do.
Consensus guidelines for the identification and treatment of biofilms in chronic non-healing wounds.
Abstract
BACKGROUND:
Despite a growing consensus that biofilms contribute to a delay in the healing of chronic wounds, conflicting evidence pertaining to their identification and management can lead to uncertainty regarding treatment. This, in part, has been driven by reliance on in vitro data or animal models, which may not directly correlate to clinical evidence on the importance of biofilms. Limited data presented in human studies have further contributed to the uncertainty. Guidelines for care of chronic wounds with a focus on biofilms are needed to help aid the identification and management of biofilms, providing a clinical focus to support clinicians in improving patient care through evidence-based medicine.
METHODS:
A Global Wound Biofilm Expert Panel, comprising 10 clinicians and researchers with expertise in laboratory and clinical aspects of biofilms, was identified and convened. A modified Delphi process, based on published scientific data and expert opinion, was used to develop consensus statements that could help identify and treat biofilms as part of the management of chronic non-healing wounds. Using an electronic survey, panel members rated their agreement with statements about biofilm identification and treatment, and the management of chronic non-healing wounds. Final consensus statements were agreed on in a face-to-face meeting.
RESULTS:
Participants reached consensus on 61 statements in the following topic areas: understanding biofilms and the problems they cause clinicians; current diagnostic options; clinical indicators of biofilms; future options for diagnostic tests; treatment strategies; mechanical debridement; topical antiseptics; screening anti-biofilm agents; and levels of evidence when choosing anti-biofilm treatments.
CONCLUSION:
This consensus document attempts to clarify misunderstandings about the role of biofilms in clinical practice, and provides a basis for clinicians to recognize biofilms in chronic non-healing wounds and manage patients optimally. A new paradigm for wound care, based on a stepped-down treatment approach, was derived from the consensus statements. This article is protected by copyright. All rights reserved.
Temperature-dependent sex-reversal by a transformer-2 gene-edited mutation in the spotted wing drosophila, Drosophila suzukii.
Abstract
Female to male sex reversal was achieved in an emerging agricultural insect pest, Drosophila suzukii, by creating a temperature-sensitive point mutation in the sex-determination gene, transformer-2 (tra-2), using CRISPR/Cas9 (clustered regularly interspaced palindromic repeats/CRISPR-associated) homology-directed repair gene-editing. Ds-tra-2 ts2 mutants developed as normal fertile XX and XY adults at permissive temperatures below 20 °C, but at higher restrictive temperatures (26 to 29 °C) chromosomal XX females developed as sterile intersexuals with a predominant male phenotype, while XY males developed with normal morphology, but were sterile. The temperature-dependent function of the Ds-TRA-2ts2 protein was also evident by the up- and down-regulation of female-specific Ds-Yolk protein 1 (Ds-Yp1) gene expression by temperature shifts during adulthood. This study confirmed the temperature-dependent function of a gene-edited mutation and provides a new method for the more general creation of conditional mutations for functional genomic analysis in insects, and other organisms. Furthermore, it provides a temperature-dependent system for creating sterile male populations useful for enhancing the efficacy of biologically-based programs, such as the sterile insect technique (SIT), to control D. suzukii and other insect pest species of agricultural and medical importance.
A dual targeted β-defensin and exome sequencing approach to identify, validate and functionally characterise genes associated with bull fertility.
Abstract
Bovine fertility remains a critical issue underpinning the sustainability of the agricultural sector. Phenotypic records collected on >7,000 bulls used in artificial insemination (AI) were used to identify 160 reliable and divergently fertile bulls for a dual strategy of targeted sequencing (TS) of fertility-related β-defensin genes and whole exome sequencing (WES). A haplotype spanning multiple β-defensin genes and containing 94 SNPs was significantly associated with fertility and functional analysis confirmed that sperm from bulls possessing the haplotype showed significantly enhanced binding to oviductal epithelium. WES of all exons in the genome in 24 bulls of high and low fertility identified 484 additional SNPs significantly associated with fertility. After validation, the most significantly associated SNP was located in the FOXJ3 gene, a transcription factor which regulates sperm function in mice. This study represents the first comprehensive characterisation of genetic variation in bovine β-defensin genes and functional analysis supports a role for β-defensins in regulating bull sperm function. This first application of WES in AI bulls with divergent fertility phenotypes has identified a novel role for the transcription factor FOXJ3 in the regulation of bull fertility. Validated genetic variants associated with bull fertility could prove useful for improving reproductive outcomes in cattle.
Whole Transcriptome Profiling: An RNA-Seq Primer and Implications for Pharmacogenomics Research.
Abstract
Pharmacogenomics has revealed compelling genetic signals associated with variability in drug response. Gene expression studies represent an additional approach to identify candidate genes accounting for drug response variability. This review focuses on insights that might be gained through analysis of the transcriptome to reveal the influence of gene expression on variable drug response. We provide a basic overview of RNA-Sequencing (RNA-Seq) and its applications, and outline advances in pharmacogenomics achievable with RNA-Seq data. This article is protected by copyright. All rights reserved.
Commensal Propionibacterium strain UF1 mitigates intestinal inflammation via Th17 cell regulation.
Abstract
Consumption of human breast milk (HBM) attenuates the incidence of necrotizing enterocolitis (NEC), which remains a leading and intractable cause of mortality in preterm infants. Here, we report that this diminution correlates with alterations in the gut microbiota, particularly enrichment of Propionibacterium species. Transfaunation of microbiota from HBM-fed preterm infants or a newly identified and cultured Propionibacterium strain, P. UF1, to germfree mice conferred protection against pathogen infection and correlated with profound increases in intestinal Th17 cells. The induction of Th17 cells was dependent on bacterial dihydrolipoamide acetyltransferase (DlaT), a major protein expressed on the P. UF1 surface layer (S-layer). Binding of P. UF1 to its cognate receptor, SIGNR1, on dendritic cells resulted in the regulation of intestinal phagocytes. Importantly, transfer of P. UF1 profoundly mitigated induced NEC-like injury in neonatal mice. Together, these results mechanistically elucidate the protective effects of HBM and P. UF1-induced immunoregulation, which safeguard against proinflammatory diseases, including NEC.
Response to Comment on Jackson et al. Insulitis in Autoantibody-Positive Pancreatic Donor With History of Gestational Diabetes Mellitus. Diabetes Care 2017;40:723-725.
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Guidelines for Developing Successful Short Advanced Courses in Systems Medicine and Systems Biology.
Abstract
Systems medicine and systems biology have inherent educational challenges. These have largely been addressed either by providing new masters programs or by redesigning undergraduate programs. In contrast, short courses can respond to a different need: they can provide condensed updates for professionals across academia, the clinic, and industry. These courses have received less attention. Here, we share our experiences in developing and providing such courses to current and future leaders in systems biology and systems medicine. We present guidelines for how to reproduce our courses, and we offer suggestions for how to select students who will nurture an interdisciplinary learning environment and thrive there.
Discovery of a widespread prokaryotic 5-oxoprolinase that was hiding in plain sight.
Abstract
5-Oxoproline (OP) is well-known as an enzymatic intermediate in the eukaryotic γ-glutamyl cycle, but it is also an unavoidable damage product formed spontaneously from glutamine and other sources. Eukaryotes metabolize OP via an ATP-dependent 5-oxoprolinase; most prokaryotes lack homologs of this enzyme (and the γ-glutamyl cycle) but are predicted to have some way to dispose of OP if its spontaneous formation in vivo is significant. Comparative analysis of prokaryotic genomes showed that the gene encoding pyroglutamyl peptidase, which removes N-terminal OP residues, clusters in diverse genomes with genes specifying homologs of a fungal lactamase (renamed prokaryotic 5-oxoprolinase A, pxpA) and homologs of allophanate hydrolase subunits (renamed pxpB and pxpC). Inactivation of Bacillus subtilis pxpA, pxpB, or pxpC genes slowed growth, caused OP accumulation in cells and medium, and prevented use of OP as a nitrogen source. Assays of cell lysates showed that ATP-dependent 5-oxoprolinase activity disappeared when pxpA, pxpB, or pxpC was inactivated. 5-Oxoprolinase activity could be reconstituted in vitro by mixing recombinant B. subtilis PxpA, PxpB, and PxpC proteins. In addition, overexpressing Escherichia coli pxpABC genes in E. coli increased 5-oxoprolinase activity in lysates ≥1700-fold. This work shows that OP is a major universal metabolite damage product and that OP disposal systems are common in all domains of life. Furthermore, it illustrates how easily metabolite damage and damage-control systems can be overlooked, even for central metabolites in model organisms.
Antibacterial Resistance in Ureaplasma Species and Mycoplasma hominis Isolates from Urine Cultures in College-Aged Females.
Abstract
Urinary tract infections (UTIs) affect nearly 20% of women age 15 to 29 and account for an estimated $3.5 billion in costs. Antibiotic resistance prolongs UTI treatment, and resistance profiles vary regionally. This regional variation is an important consideration in guiding empirical treatment selection. Regional studies in the United States have identified tetracycline resistance in over one-third of Ureaplasma species isolates, but no studies have evaluated antibiotic resistance levels in college-aged women with a first-time UTI. We tested a panel of antibiotics and determined the MICs of Ureaplasma species (60 U. parvum and 13 U. urealyticum) and 10 Mycoplasma hominis isolates obtained from urine from college-aged women with a first-time UTI. Low antibiotic resistance was found in this population of women with a first-time UTI. All M. hominis and U. urealyticum isolates were sensitive. However, two U. parvum isolates were resistant, with one to levofloxacin (MIC, 4 μg/ml) and one to tetracycline (MIC, 8 μg/ml). For the Ureaplasma spp., the MIC90s were highest against gentamicin (21 μg/ml) and lowest against doxycycline (0.25 μg/ml). In a comparison of MIC levels between Ureaplasmaspp., U. urealyticum had significantly higher MICs against each antibiotic except doxycycline. For the resistant isolates, the genetic mechanisms of resistance were determined. PCR amplification identified tetM to be present in the tetracycline-resistant isolate and an S83W mutation within the parC gene of the quinolone-resistant isolate. To our knowledge, this study is the first to provide molecular and phenotypic evidence of the S83W parC mutation conferring levofloxacin resistance in U. parvum isolated from a patient in the United States.
Identification of Novel Growth Regulators in Plant Populations Expressing Random Peptides.
Abstract
The use of chemical genomics approaches allows the identification of small molecules that integrate into biological systems, thereby changing discrete processes that influence growth, development, or metabolism. Libraries of chemicals are applied to living systems, and changes in phenotype are observed, potentially leading to the identification of new growth regulators. This work describes an approach that is the nexus of chemical genomics and synthetic biology. Here, each plant in an extensive population synthesizes a unique small peptide arising from a transgene composed of a randomized nucleic acid sequence core flanked by translational start, stop, and cysteine-encoding (for disulfide cyclization) sequences. Ten and 16 amino acid sequences, bearing a core of six and 12 random amino acids, have been synthesized in Arabidopsis (Arabidopsis thaliana) plants. Populations were screened for phenotypes from the seedling stage through senescence. Dozens of phenotypes were observed in over 2,000 plants analyzed. Ten conspicuous phenotypes were verified through separate transformation and analysis of multiple independent lines. The results indicate that these populations contain sequences that often influence discrete aspects of plant biology. Novel peptides that affect photosynthesis, flowering, and red light response are described. The challenge now is to identify the mechanistic integrations of these peptides into biochemical processes. These populations serve as a new tool to identify small molecules that modulate discrete plant functions that could be produced later in transgenic plants or potentially applied exogenously to impart their effects. These findings could usher in a new generation of agricultural growth regulators, herbicides, or defense compounds.
An antigen-specific semi-therapeutic treatment with local delivery of tolerogenic factors through a dual-sized microparticle system blocks experimental autoimmune encephalomyelitis.
Abstract
Antigen-specific treatments are highly desirable for autoimmune diseases in contrast to treatments which induce systemic immunosuppression. A novel antigen-specific therapy has been developed which, when administered semi-therapeutically, is highly efficacious in the treatment of the mouse model for multiple sclerosis, experimental autoimmune encephalomyelitis (EAE). The treatment uses dual-sized, polymeric microparticles (dMPs) loaded with specific antigen and tolerizing factors for intra- and extra-cellular delivery, designed to recruit and modulate dendritic cells toward a tolerogenic phenotype without systemic release. This approach demonstrated robust efficacy and provided complete protection against disease. Therapeutic efficacy required encapsulation of the factors in controlled-release microparticles and was antigen-specific. Disease blocking was associated with a reduction of infiltrating CD4+ T cells, inflammatory cytokine-producing pathogenic CD4+ T cells, and activated macrophages and microglia in the central nervous system. Furthermore, CD4+ T cells isolated from dMP-treated mice were anergic in response to disease-specific, antigen-loaded splenocytes. Additionally, the frequency of CD86hiMHCIIhi dendritic cells in draining lymph nodes of EAE mice treated with Ag-specific dMPs was reduced. Our findings highlight the efficacy of microparticle-based drug delivery platform to mediate antigen-specific tolerance, and suggest that such a multi-factor combinatorial approach can act to block autoimmunity.
A pathologist’s perspective on induced pluripotent stem cells.
Abstract
Induced pluripotent stem cell (iPSC) technology was originally developed in 2006. Essentially, it converts somatic cells into pluripotent stem cells by transiently expressing a few transcriptional factors. Once generated, these iPSCs can differentiate into all the cell types of our body, theoretically, which has attracted great attention for clinical research including disease pathobiology studies. Could this technology then become an additional research or diagnostic tool widely available to practicing pathologists? Here we summarize progress in iPSC research toward disease pathobiology studies, its future potential, and remaining problems from a pathologist’s perspective. A particular focus will be on introducing the effort to recapitulate disease-related morphological changes through three-dimensional culture of stem cells such as organoid differentiation.
The evolutionary history of the DMRT3 ‘Gait keeper’ haplotype.
Abstract
A previous study revealed a strong association between the DMRT3:Ser301STOP mutation in horses and alternate gaits as well as performance in harness racing. Several follow-up studies have confirmed a high frequency of the mutation in gaited horse breeds and an effect on gait quality. The aim of this study was to determine when and where the mutation arose, to identify additional potential causal mutations and to determine the coalescence time for contemporary haplotypes carrying the stop mutation. We utilized sequences from 89 horses representing 26 breeds to identify 102 SNPs encompassing the DMRT3 gene that are in strong linkage disequilibrium with the stop mutation. These 102 SNPs were genotyped in an additional 382 horses representing 72 breeds, and we identified 14 unique haplotypes. The results provided conclusive evidence that DMRT3:Ser301STOP is causal, as no other sequence polymorphisms showed an equally strong association to locomotion traits. The low sequence diversity among mutant chromosomes demonstrated that they must have diverged from a common ancestral sequence within the last 10 000 years. Thus, the mutation occurred either just before domestication or more likely some time after domestication and then spread across the world as a result of selection on locomotion traits.
Chilling-responsive DEMETER-LIKE DNA demethylase mediates in poplar bud break.
Abstract
Annual dormancy-growth cycle is a developmental and physiological process essential for the survival of deciduous trees in temperate and boreal forests. Seasonal control of shoot growth in woody perennials requires specific genetic programmes responding to environmental signals. The environmental-controlled mechanisms that regulate the shift between winter dormancy and the growth-promoting genetic programmes are still unknown. Here, we show that dynamics in genomic DNA methylation levels are involved in the regulation of dormancy-growth cycle in poplar. The reactivation of growth in the apical shoot during bud break process in spring is preceded by a progressive reduction of genomic DNA methylation in apex tissue. The induction in apex tissue of a chilling-dependent poplar DEMETER-LIKE 10 (PtaDML10) DNA demethylase precedes shoot growth reactivation. Transgenic poplars showing downregulation of PtaDML8/10 caused delayed bud break. Genome-wide transcriptome and methylome analysis and data mining revealed that the gene targets of DEMETER-LIKE-dependent DNA demethylation are genetically associated with bud break. These data point to a chilling-dependent DEMETER-like DNA demethylase mechanisms being involved in the shift from winter dormancy to a condition that precedes shoot apical vegetative growth in poplar.
Life-extending dietary restriction and ovariectomy each increase leucine oxidation and alter leucine allocation in grasshoppers.
Abstract
Reduced reproduction and dietary restriction each extend lifespan in many animal models, but possible contributions of nutrient oxidation and allocation are largely unknown. Ovariectomy and eating 70% of ad libitum-feeding each extend lifespan in lubber grasshoppers. When feeding levels between the two groups are matched, ovariectomy increases fat and protein storage while dietary restriction reduces fat storage. Because of these disparities in nutrient investment, metabolism may differ between these two life-extending treatments. Therefore, we examined the allocation and organismal oxidation of one representative of each macronutrient class: leucine, oleic acid, and glucose. Ovariectomy and dietary restriction each increased oxidation of dietary leucine. Dietary leucine may play a special role in aging because amino acids stimulate cellular growth. Speeding oxidation of leucine may attenuate cellular growth. Allocation of leucine to muscle was the clearest difference between ovariectomy and dietary restriction in this study. Ovariectomy reduced allocation of leucine to femur muscle, whereas dietary restriction increased allocation of leucine to femur muscle. This allocation likely corresponds to muscle maintenance for locomotion, suggesting dietary restriction increases support for locomotion, perhaps to search for food. Last, ovariectomy decreased oxidation of dietary oleic acid and glucose, perhaps to save them for storage, but the site of storage is unclear. This study suggests that the oxidation of branched-chain amino acids may be an underappreciated mechanism underlying lifespan extension.
Controlled single bubble cavitation collapse results in jet-induced injury in brain tissue.
Abstract
Multiscale damage due to cavitation is considered as a potential mechanism of traumatic brain injury (TBI) associated with explosion. In this study, we employed a TBI relevant hippocampal ex vivo slice model to induce bubble cavitation. Placement of single reproducible seed bubbles allowed control of size, number, and tissue location to visualize and measure deformation parameters. Maximum strain value was measured at 45 µs after bubble collapse, presented with a distinct contour and coincided temporally and spatially with the liquid jet. Composite injury maps combined this maximum strain value with maximum measured bubble size and location along with histological injury patterns. This facilitated the correlation of bubble location and subsequent jet direction to the corresponding regions of high strain which overlapped with regions of observed injury. A dynamic threshold strain range for tearing of cerebral cortex was estimated to be between 0.5 and 0.6. For a seed bubble placed underneath the hippocampus, cavitation induced damage was observed in hippocampus (local), proximal cerebral cortex (marginal) and the midbrain/forebrain (remote) upon histological evaluation. Within this test model, zone of cavitation injury was greater than the maximum radius of the bubble. Separation of apposed structures, tissue tearing, and disruption of cellular layers defined early injury patterns that were not detected in the blast-exposed half of the brain slice. Ultrastructural pathology of the neurons exposed to cavitation was characterized by disintegration of plasma membrane along with loss of cellular content. The developed test system provided a controlled experimental platform to study cavitation induced high strain deformations on brain tissue slice. The goal of the future studies will be to lower underpressure magnitude and cavitation bubble size for more sensitive evaluation of injury.
Histopathological and proteomic responses in male Chinese rare minnow (Gobiocypris rarus) indicate hepatotoxicity following benzotriazole exposure.
Abstract
Benzotriazole (BT) and its associated derivatives are used ubiquitously in industrial processes, and can be detected in indoor temperature coolants and in chemicals designed to inhibit corrosion. This chemical has been widely detected in aquatic environments and shows some degree of environmental persistence. Evidence has shown that BT exposure can negatively affect endocrine systems and can result in neurotoxicity in fish. However, no study has examined whether this chemical exhibits hepatotoxicity in fish, and if so, what are the underlying mechanism associated with the damage. To address this knowledge gap, we measured the liver proteome of adult male Chinese rare minnow (Gobiocypris rarus) exposed to either 0.05, 0.5, or 5 mg/L BT for 28 days. Overall, 17 proteins were induced and 9 were reduced in abundance following BT treatment (ratio > 1.5, p < 0.05). Pathway analysis revealed that cellular processes affected by BT included xenobiotic clearance, oxidative stress response, apoptosis, and translation. Moreover, transcripts related to these toxic pathways were also significantly affected by BT. In addition, rare minnows exposed to BT showed signs of hypertrophy of hepatocytes, nuclei pyknosis, and higher levels of cellular vacuolization compared to the controls, thus these early proteomic responses in the liver may be related to pathology (i.e. adverse outcome pathway). Our data demonstrate that BT dysregulates molecular responses in the liver and tissue pathology indicative of damage. This study provides new insight into BT hepatotoxicity in Chinese rare minnow.
Enrichment of IL-17A+ IFN-γ+ and IL-22+ IFN-γ+ T cell subsets is associated with reduction of NKp44+ ILC3s in the terminal ileum of Crohn’s disease patients.
Abstract
Crohn’s disease (CD) is a chronic inflammatory condition of the human gastrointestinal tract whose aetiology remains largely unknown. Dysregulated adaptive immune responses and defective innate immunity both contribute to this process. In this study, we demonstrated that the interleukin (IL)-17A+ interferon (IFN)-γ+ and IL-22+ IFN-γ+ T cell subsets accumulated specifically in the inflamed terminal ileum of CD patients. These cells had higher expression of Ki-67 and were active cytokine producers. In addition, their proportions within both the IL-17A-producer and IL-22-producer populations were increased significantly. These data suggest that IL-17A+ IFN-γ+ and IL-22+IFN-γ+ T cell subsets might represent the pathogenic T helper type 17 (Th17) population in the context of intestinal inflammation for CD patients. In the innate immunity compartment we detected a dramatic alteration of both phenotype and function of the intestinal innate lymphoid cells (ILCs), that play an important role in the maintenance of mucosal homeostasis. In the inflamed gut the frequency of the NKp44– CD117– ILC1s subset was increased significantly, while the frequency of NKp44+ ILC3s was reduced. Furthermore, the frequency of human leucocyte antigen D-related (HLA-DR)-expressing-NKp44+ ILC3s was also reduced significantly. Interestingly, the decrease in the NKp44+ ILC3s population was associated with an increase of pathogenic IL-17A+ IFN-γ+ and IL-22+ IFN-γ+ T cell subsets in the adaptive compartment. This might suggest a potential link between NKp44+ ILC3s and the IL-17A+ IFN-γ+ and IL-22+ IFN-γ+ T cell subsets in the terminal ileum of CD patients.
Association of Common Genetic Variants With Contralateral Breast Cancer Risk in the WECARE Study.
Abstract
BACKGROUND:
Women with unilateral breast cancer (UBC) are at risk of developing a subsequent contralateral breast cancer (CBC). Common variants are associated with breast cancer risk. Whether these influence CBC risk is unknown.
METHODS:
Participants were breast cancer cases from the population-based Women’s Environmental Cancer and Radiation Epidemiology (WECARE) Study. Sixty-seven established breast cancer risk loci were genotyped directly or by imputation in 1459 case subjects with CBC and 2126 UBC control subjects. An unweighted polygenic risk score (PRS) was created by summing the number of risk alleles for each directly genotyped single nucleotide polymorphism (SNP), or for imputed loci, the imputed dosage. A weighted PRS was calculated similarly, but where each SNP’s contribution was weighted by the published per-allele log odds ratio. Unweighted and weighted polygenic risk scores and CBC risk were modeled using conditional logistic regression. Cumulative CBC risk was estimated and benchmarked using Surveillance, Epidemiology, and End Results population incidence rates.
RESULTS:
Both unweighted and weighted PRS were statistically significantly associated with CBC risk. The adjusted risk ratio of CBC in women in the upper quartile of unweighted PRS compared with the lowest quartile was 1.63 (95% confidence interval [CI] = 1.33 to 2.00). The estimated 10-year cumulative risk for women in the upper quartile of the unweighted PRS was 7.4% (95% CI = 6.0% to 9.1%). For women in the upper quartile of the weighted PRS, the risk ratio for CBC was 1.75 (95% CI = 1.41 to 2.18) compared with women in the lowest quartile. There was no statistically significant heterogeneity by age, treatment (radiation therapy dose, tamoxifen, chemotherapy), estrogen receptor status of the first primary, histology of the first primary, length of at-risk period for CBC, or breast cancer family history.
CONCLUSIONS:
Common genomic variants associated with the development of first primary breast cancer are also associated with the development of CBC; the risk is strongest among those who carry more risk alleles.
Erdj3 Has an Essential Role for Z Variant Alpha-1-Antitrypsin Degradation.
Abstract
Alpha-1-antitrypsin deficiency (AATD) is an inherited disease characterized by emphysema and liver disease. AATD is most often caused by a single amino acid substitution at amino acid 342 in the mature protein, resulting in the Z mutation of the alpha-1-antitrypsin gene (ZAAT). This substitution is associated with misfolding and accumulation of ZAAT in the endoplasmic reticulum (ER) of hepatocytes and monocytes, causing a toxic gain of function. Retained ZAAT is eliminated by ER-associated degradation and autophagy. We hypothesized that alpha-1-antitrypsin (AAT)-interacting proteins play critical roles in quality control of human AAT. Using co-immunoprecipitation, we identified ERdj3, an ER-resident Hsp40 family member, as a part of the AAT trafficking network. Depleting ERdj3 increased the rate of ZAAT degradation in hepatocytes by redirecting ZAAT to the ER calreticulin-EDEM1 pathway, followed by autophagosome formation. In the Huh7.5 cell line, ZAAT ER clearance resulted from enhancing ERdj3-mediated ZAAT degradation by silencing ERdj3 while simultaneously enhancing autophagy. In this context, ERdj3 suppression may eliminate the toxic gain of function associated with polymerization of ZAAT, thus providing a potential new therapeutic approach to the treatment of AATD-related liver disease. J. Cell. Biochem. 118: 3090-3101, 2017. © 2017 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals Inc.
How consistent are we? Interlaboratory comparison study in fathead minnows using the model estrogen 17α-ethinylestradiol to develop recommendations for environmental transcriptomics.
Abstract
Fundamental questions remain about the application of omics in environmental risk assessments, such as the consistency of data across laboratories. The objective of the present study was to determine the congruence of transcript data across 6 independent laboratories. Male fathead minnows were exposed to a measured concentration of 15.8 ng/L 17α-ethinylestradiol (EE2) for 96 h. Livers were divided equally and sent to the participating laboratories for transcriptomic analysis using the same fathead minnow microarray. Each laboratory was free to apply bioinformatics pipelines of its choice. There were 12 491 transcripts that were identified by one or more of the laboratories as responsive to EE2. Of these, 587 transcripts (4.7%) were detected by all laboratories. Mean overlap for differentially expressed genes among laboratories was approximately 50%, which improved to approximately 59.0% using a standardized analysis pipeline. The dynamic range of fold change estimates was variable between laboratories, but ranking transcripts by their relative fold difference resulted in a positive relationship for comparisons between any 2 laboratories (mean R2 > 0.9, p < 0.001). Ten estrogen-responsive genes encompassing a fold change range from dramatic (>20-fold; e.g., vitellogenin) to subtle (∼2-fold; i.e., block of proliferation 1) were identified as differentially expressed, suggesting that laboratories can consistently identify transcripts that are known a priori to be perturbed by a chemical stressor. Thus, attention should turn toward identifying core transcriptional networks using focused arrays for specific chemicals. In addition, agreed-on bioinformatics pipelines and the ranking of genes based on fold change (as opposed to p value) should be considered in environmental risk assessment. These recommendations are expected to improve comparisons across laboratories and advance the use of omics in regulations. Environ Toxicol Chem 2017;36:2593-2601. © 2017 SETAC.
Intramammary 1,25-dihydroxyvitamin D3 treatment increases expression of host-defense genes in mammary immune cells of lactating dairy cattle.
Abstract
Bacterial infection of the mammary gland activates an intracrine vitamin D pathway in macrophages of dairy cows. The active hormone of the vitamin D pathway, 1,25-dihydroxyvitamin D3 (1,25D), stimulates nitric oxide and β-defensin responses in bovine monocyte cultures, but the effect of 1,25D on innate immune genes in the mammary gland remained unknown. Therefore, the objective of this study was to determine the effects intramammary 1,25D treatment on expression of vitamin D associated host-defenses of the bovine mammary gland. Intramammary treatment of normal, healthy mammary glands of lactating dairy cows (n=14) with 10μg 1,25D increased inducible nitric oxide synthase (iNOS) and β-defensin 7 (DEFB7) gene expression in total milk somatic cells more than two-fold relative to placebo-treated glands within 8h after treatment. The vitamin D 24-hydroxylase gene (CYP24A1) also was increased nearly 100-fold in 1,25D-treated glands within 4h after treatment but was not affected in placebo-treated glands. Both macrophages and neutrophils isolated from milk had increased CYP24A1 expression in response to 1,25D treatment but only macrophages had increased iNOS expression. Repeated intramammary 1,25D treatment, every 12h for 48h, of infected mammary glands of cows diagnosed with subclinical mastitis resulted in increased expression of CYP24A1, DEFB4, DEFB7 and iNOS genes compared to placebo-treated glands. The 1,25D treatment resulted in elevated serum 1,25D concentrations (55 vs 33pg/mL) compared to placebo but it did not change serum calcium concentrations or bacteria counts in milk of infected mammary glands. In conclusion, 1,25D upregulates iNOS and β-defensin genes in vivo in cattle and affirms earlier reports that vitamin D supports innate immune functions of cattle.
Testing the influence of surfactant-based wound dressings on proteinase activity.
Abstract
Proteinases are enzymes that can digest other proteins. In chronic wounds, a sub-class of these enzymes with the ability to degrade the extracellular matrix (matrix metalloproteinases, MMPs) have been found to both inhibit healing and to be able to aid in enzymatically debriding a wound. Enzymatic debridement using the enzymes present in a wound is generally called autolytic debridement. Clinicians seeking to employ autolytic debridement typically use occlusive materials such as medical honey, alginate dressings and other occlusive dressings. A relatively new class of gel dressings comprised of surfactants are now available for clinical use. A variety of surfactants are used in the study of MMP biochemistry. Surfactants can deactivate MMPs or can enhance their activity, depending on the surfactant. In order to begin to understand how the MMPs found in chronic wounds would respond to these new dressings, we tested a serial dilution series of two of the currently available surfactant-based dressings to determine their effects on four separate MMPs. The dose-response versus MMP activity of bacterial collagenase, host-derived MMP-8 and MMPs-2 and -9 was assessed using a simple mix-and-read fluorescent peptide activity assay. The enzyme’s native activity in the absence of the gel was used to compare against the surfactant-treated samples. We found that the surfactant affected the proteinase activity differently for each enzyme. The activity of the bacterial collagenase was increased at low concentrations but slightly inhibited as the concentrations increased. The host MMP-8 collagenase responded similarly in that it was inhibited at higher concentrations. Interestingly, both MMP gelatinases presented with substantially increased activities, with MMP-2 increased to 200% of native activity, while MMP-9 presented with an increase of 300% activity over the same concentration range. MMPs appear to respond to a surfactant-based gel dressing differentially, with the MMP most commonly elevated in chronic wounds having the highest boost to activity. In wounds with elevated MMPs, our data suggest that the use of these surfactant-based dressings would be expected to enhance the activity of MMPs 2 and 9 gelatinases while simultaneously inhibiting MMP-8 collagenase. Hypothetically, this imbalanced effect would support a protection of the native dermal collagen and removal of denatured materials. However, the demonstration of these anticipated consequences is still being investigated.
Bioequivalence of a Liquid Formulation of Alpha1-Proteinase Inhibitor Compared with Prolastin®-C (Lyophilized Alpha1-PI) in Alpha1-Antitrypsin Deficiency.
Abstract
This study evaluated the bioequivalence, safety, and immunogenicity of a new liquid formulation of human plasma-derived alpha1-proteinase inhibitor, Liquid Alpha1-PI, compared with the Lyophilized Alpha1-PI formulation (Prolastin®-C), for augmentation therapy in patients with alpha1-antitrypsin deficiency (AATD). In this double-blind, randomized, 20-week crossover study, 32 subjects with AATD were randomized to receive 8 weekly infusions of 60 mg/kg of Liquid Alpha1-PI or Lyophilized Alpha1-PI. Serial blood samples were drawn for 7 days after the last dose followed by 8 weeks of the alternative treatment. The primary endpoint was bioequivalence at steady state, as measured by area under the concentration versus time curve from 0 to 7 days (AUC0-7 days) postdose using an antigenic content assay. Bioequivalence was defined as 90% confidence interval (CI) for the ratio of the geometric least squares (LS) mean of AUC0-7 days for both products within the limits of 0.80 and 1.25. Safety and immunogenicity were assessed. Mean alpha1-PI concentration versus time curves for both formulations were superimposable. Mean AUC0-7 days was 20 320 versus 19 838 mg × h/dl for Liquid Alpha1-PI and Lyophilized Alpha1-PI, respectively. The LS mean ratio of AUC0-7 days (90% CI) for Liquid Alpha1-PI versus Lyophilized Alpha1-PI was 1.05 (1.03-1.08), indicating bioequivalence. Liquid Alpha1-PI was well tolerated and adverse events were consistent with Lyophilized Alpha1-PI. Immunogenicity to either product was not detected. In conclusion, Liquid Alpha1-PI is bioequivalent to Lyophilized Alpha1-PI, with a similar safety profile. The liquid formulation would eliminate the need for reconstitution and shorten preparation time for patients receiving augmentation therapy for AATD.
Complete Genomic Sequence of Dengue Virus Serotype 4 Isolated from Plasma Collected from a Haitian Child in 2014.
Abstract
While data are limited, there is increasing evidence that infections by dengue viruses are endemic in Haiti. In 2014, an outbreak caused by dengue virus 4 (DENV-4) followed a chikungunya fever outbreak. We present here the complete genome sequence of one isolate grouped within the genotype II South America and Caribbean DENV-4 clades.
Hydrogen Peroxide Response in Leaves of Poplar (Populus simonii × Populus nigra) Revealed from Physiological and Proteomic Analyses.
Abstract
Hydrogen peroxide (H₂O₂) is one of the most abundant reactive oxygen species (ROS), which plays dual roles as a toxic byproduct of cell metabolism and a regulatory signal molecule in plant development and stress response. Populus simonii × Populus nigra is an important cultivated forest species with resistance to cold, drought, insect and disease, and also a key model plant for forest genetic engineering. In this study, H₂O₂ response in P. simonii × P. nigra leaves was investigated using physiological and proteomics approaches. The seedlings of 50-day-old P. simonii × P. nigra under H₂O₂ stress exhibited stressful phenotypes, such as increase of in vivo H₂O₂ content, decrease of photosynthetic rate, elevated osmolytes, antioxidant accumulation, as well as increased activities of several ROS scavenging enzymes. Besides, 81 H₂O₂-responsive proteins were identified in the poplar leaves. The diverse abundant patterns of these proteins highlight the H₂O₂-responsive pathways in leaves, including 14-3-3 protein and nucleoside diphosphate kinase (NDPK)-mediated signaling, modulation of thylakoid membrane structure, enhancement of various ROS scavenging pathways, decrease of photosynthesis, dynamics of proteins conformation, and changes in carbohydrate and other metabolisms. This study provides valuable information for understanding H₂O₂-responsive mechanisms in leaves of P. simonii × P. nigra.
Psychiatric Genomics: An Update and an Agenda.
Abstract
The Psychiatric Genomics Consortium (PGC) is the largest consortium in the history of psychiatry. This global effort is dedicated to rapid progress and open science, and in the past decade it has delivered an increasing flow of new knowledge about the fundamental basis of common psychiatric disorders. The PGC has recently commenced a program of research designed to deliver “actionable” findings-genomic results that 1) reveal fundamental biology, 2) inform clinical practice, and 3) deliver new therapeutic targets. The central idea of the PGC is to convert the family history risk factor into biologically, clinically, and therapeutically meaningful insights. The emerging findings suggest that we are entering a phase of accelerated genetic discovery for multiple psychiatric disorders. These findings are likely to elucidate the genetic portions of these truly complex traits, and this knowledge can then be mined for its relevance for improved therapeutics and its impact on psychiatric practice within a precision medicine framework.
Towards standards for human fecal sample processing in metagenomic studies.
Abstract
Technical variation in metagenomic analysis must be minimized to confidently assess the contributions of microbiota to human health. Here we tested 21 representative DNA extraction protocols on the same fecal samples and quantified differences in observed microbial community composition. We compared them with differences due to library preparation and sample storage, which we contrasted with observed biological variation within the same specimen or within an individual over time. We found that DNA extraction had the largest effect on the outcome of metagenomic analysis. To rank DNA extraction protocols, we considered resulting DNA quantity and quality, and we ascertained biases in estimates of community diversity and the ratio between Gram-positive and Gram-negative bacteria. We recommend a standardized DNA extraction method for human fecal samples, for which transferability across labs was established and which was further benchmarked using a mock community of known composition. Its adoption will improve comparability of human gut microbiome studies and facilitate meta-analyses.
Time to revisit warfarin pharmacogenetics.
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NOTE: These abstracts were retrieved from the U.S. National Library of Medicine website managed in collaboration with the U.S. National Library of Medicine