UFGI Publications Round-up Week 11/21/2016

Transgenic mice overexpressing the ALS-linked protein Matrin 3 develop a profound muscle phenotype.

Author information: Moloney C^1,2, Rayaprolu S^1,2, Howard J^1,2, Fromholt S^1,2, Brown H^1,2, Collins M^1,2, Cabrera M^1,2, Duffy C^1,2, Siemienski Z^1,2, Miller D^1,2, Swanson MS³, Notterpek L^1,2,4, Borchelt DR^5,6,7, Lewis J^8,9,10.

Journal: Acta Neuropathologica Communications

Date of e-pub: November 2016

Abstract: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder of upper and lower motor neurons. Mutations in the gene encoding the nuclear matrix protein Matrin 3 have been found in familial cases of ALS, as well as autosomal dominant distal myopathy with vocal cord and pharyngeal weakness. We previously found that spinal cord and muscle, organs involved in either ALS or distal myopathy, have relatively lower levels of Matrin 3 compared to the brain and other peripheral organs in the murine system. This suggests that these organs may be vulnerable to any changes in Matrin 3. In order to determine the role of Matrin 3 in these diseases, we created a transgenic mouse model for human wild-type Matrin 3 using the mouse prion promoter (MoPrP) on a FVB background.We identified three founder transgenic lines that produced offspring in which mice developed either hindlimb paresis or paralysis with hindlimb and forelimb muscle atrophy. Muscles of affected mice showed a striking increase in nuclear Matrin 3, as well as the presence of rounded fibers, vacuoles, nuclear chains, and subsarcolemmal nuclei. Immunoblot analysis of the gastrocnemius muscle from phenotypic mice showed increased levels of Matrin 3 products migrating at approximately 120 (doublet), 90, 70, and 55 kDa. While there was no significant change in the levels of Matrin 3 in the spinal cord in the phenotypic mice, the ventral horn contained individual cells with cytoplasmic redistribution of Matrin 3, as well as gliosis. The phenotypes of these mice indicate that dysregulation of Matrin 3 levels is deleterious to neuromuscular function.

 

 

Transfer of Therapeutic Genes into Fetal Rhesus Monkeys using Recombinant Adeno-Associated Type I Viral Vectors.

Author information: Conlon TJ¹, Mah CS², Pacak CA³, Rucker Henninger MB⁴, Erger KE⁵, Jorgensen ML⁶, Lee CC⁷, Tarantal AF⁸, Byrne BJ^9,10.

Journal: Human Gene Therapy. Clinical Development.

Date of e-pub: November 2016

Abstract: Neuromuscular disorders such as Pompe disease (glycogen storage disease, type II), result in early and potentially irreversible cellular damage with a very limited opportunity for intervention in the newborn period. Pompe disease is due to deficiency in acid α-glucosidase (GAA) leading to lysosomal accumulation of glycogen in all cell types, abnormal myofibrillogenesis, respiratory insufficiency, neurological deficits, and reduced contractile function in striated muscle. Previous studies have shown that fetal delivery of recombinant adeno-associated virus (rAAV) encoding GAA to the peritoneal cavity of Gaa-/- mice resulted in high-level transduction of the diaphragm. While progression of other genetic disorders may occur later in life, the potential of fetal gene delivery to avoid onset of irreversible damage suggests it is an attractive option for many inherited diseases. In this study, rhesus monkey fetuses were administered 4.5×1012 particles of rAAV type 1 expressing either human GAA (rAAV1-CMV-hGAA), human mini-dystrophin (rAAV1-CMV-miniDMD), or human α-1-antitrypsin (rAAV1-CBA-hAAT) in the first trimester using an established intraperitoneal ultrasound-guided approach. Fetuses were monitored sonographically and newborns delivered at term for postnatal studies. All animals remained healthy during the study period (growth, hematology, clinical chemistry), with no evidence of adverse effects. Tissues were collected at 3 months postnatal age (~7 months post-fetal gene transfer) for immunohistochemistry (IHC) and qPCR. Both diaphragm and peritoneum from vector-treated animals were strongly positive for expression of human GAA, Dystrophin, or AAT by IHC, similar to findings when reporter genes were used. Protein expression in the diaphragm and peritoneum correlated with high vector copy numbers detected by real-time PCR. Other anatomical areas were negative, although the liver showed minimal evidence of human GAA, DMD, and AAT vector genomes. In summary, delivery of rAAV vectors provided stable transduction of the muscular component of the diaphragm without any evidence of adverse effects.

 

 

Unravelling the genomic architecture of bull fertility in Holstein cattle.

Author information: Han Y^1,2, Peñagaricano F^3,4.

Journal: BMC Genetics

Date of e-pub: November 2016

Abstract: Fertility is considered an important economic trait in dairy cattle. Most studies have investigated cow fertility while bull fertility has received much less consideration. The main objective of this study was to perform a comprehensive genomic analysis in order to unravel the genomic architecture underlying sire fertility in Holstein dairy cattle. The analysis included the application of alternative genome-wide association mapping approaches and the subsequent use of diverse gene set enrichment tools.

The association analyses identified at least eight genomic regions strongly associated with bull fertility. Most of these regions harbor genes, such as KAT8, CKB, TDRD9 and IGF1R, with functions related to sperm biology, including sperm development, motility and sperm-egg interaction. Moreover, the gene set analyses revealed many significant functional terms, including fertilization, sperm motility, calcium channel regulation, and SNARE proteins. Most of these terms are directly implicated in sperm physiology and male fertility.

This study contributes to the identification of genetic variants and biological processes underlying sire fertility. These findings can provide opportunities for improving bull fertility via marker-assisted selection.

 

 

Neuroanatomical characterization of the cellular and axonal architecture of subcortical band heterotopia in the BXD29-Tlr4lps-2J/J mouse cortex.

Author information: Ramos RL¹, Toia AR², Pasternack DM², Dotzler TP², Cuoco JA², Esposito AW², Le MM³, Parker AK³, Goodman JH⁴, Sarkisian MR⁵.

Journal: Neuroscience

Date of e-pub: November 2016

Abstract: Subcortical band heterotopia (SBH) are malformations of the human cerebral cortex typically associated with epilepsy and cognitive delay/disability. Rodent models of SBH have demonstrated strong face validity as they are accompanied by both cognitive deficits and spontaneous seizures or reduced seizure threshold. BXD29-Tlr4^lps-2J/J recombinant inbred mice display striking bilateral SBH, partial callosal agenesis, morphological changes in subcortical structures of the auditory pathway, and display sensory deficits in behavioral tests (Rosen et al., 2013; Truong et al., 2013, 2015). Surprisingly, these mice show no cognitive deficits and have a higher seizure threshold to chemi-convulsive treatment (Gabel et al., 2013) making them different than other rodent SBH models described previously. In the present report, we perform a detailed characterization of the cellular and axonal constituents of SBH in BXD29-Tlr4^lps-2J/J mice and demonstrate that various types of interneurons and glia as well as cortical and subcortical projections are found in SBH. In addition, the length of neuronal cilia was reduced in SBH compared to neurons in the overlying and adjacent normotopic cortex. Finally, we describe additional and novel malformations of the hippocampus and neocortex present in BXD29-Tlr4^lps-2J/J mice. Together, our findings in BXD29-Tlr4^lps-2J/J mice are discussed in the context of the known neuroanatomy and phenotype of other SBH rodent models.

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