Project description:We identified genes expressed in mouse skeletal muscle, during the process of muscle regeneration after injury, which are dysregulated in the absence of Mef2a expression. MEF2A is a member of the evolutionarily conserved MEF2 transcription factor family which has known roles in cardiac muscle development and function, but is not well studied in skeletal muscle. We performed a comparison of gene expression profiles in wild type and MEF2A knockout tibialis anterior muscle, seven days post-injury with cardiotoxin. The results indicated that a variety of genes expressed during muscle regeneration, predominantly microRNAs in the Gtl2-Dio3 locus, are dysregulated by the loss of MEF2A expression. Skeletal muscle RNA used in the present study included the following two sample groups: (WT) pooled total RNA from tibialis anterior muscle taken from 5 wild type mice at seven days post-injury with 10uM cardiotoxin; (KO) pooled total RNA from tibialis anterior muscle taken from 5 Mef2a knockout mice at seven days post-injury with 10uM cardiotoxin. All mice were between 2-4 months of age. Both male and female mice were used.
Project description:We identified genes expressed in mouse skeletal muscle, during the process of muscle regeneration after injury, which are dysregulated in the absence of Mef2a expression. MEF2A is a member of the evolutionarily conserved MEF2 transcription factor family which has known roles in cardiac muscle development and function, but is not well studied in skeletal muscle. We performed a comparison of gene expression profiles in wild type and MEF2A knockout tibialis anterior muscle, seven days post-injury with cardiotoxin. The results indicated that a variety of genes expressed during muscle regeneration, predominantly microRNAs in the Gtl2-Dio3 locus, are dysregulated by the loss of MEF2A expression.
Project description:In this study, we have identified MEF2A-sensitive genes in atrial and ventricular chambers of the adult heart. MEF2A is a member of the myocyte enhancer factor 2 (MEF2) family of transcription factors. MEF2 proteins are expressed in skeletal and cardiac muscle tissues and are conserved across many mammalian species, but the gene programs regulated by MEF2A in adult cardiac chambers are largely unknown. We compared gene expression profiles between WT and Mef2a knockout atria and ventricles from adult mice, and the results identified distinct and overlapping sets of genes sensitive to the loss of MEF2A in the adult heart.
Project description:In this study, CUT&Tag-seq technology was employed to investigate MEF2A binding sites across the entire genome of chicken primary myoblasts. CUT&Tag was performed using CUT&Tag Assay Kit for Illumina Pro (TD904-1) from Vazyme. Antibody targeting MEF2A as well as IgG were used.The final DNA library on a HiSeq PE150 platform was subjected for the analyses. This study provides a wide landscape of MEF2A target genes from chicken primary myoblasts, which supports the active role of MEF2A in avian muscle development.
Project description:We analyzed the functional role of DOR (Diabetes and Obesity Regulated gene) (also named Tp53inp2) in skeletal muscle. We show that DOR has a direct impact on skeletal muscle mass in vivo. Thus, using different transgenic mouse models, we demonstrate that while muscle-specific DOR gain-of-function results in reduced muscle mass, loss-of-function causes muscle hypertrophy. DOR has been described as a protein with two different functions, i.e., a nuclear coactivator and an autophagy regulator (Baumgartner et. al., PLoS One, 2007; Francis et. al., Curr Biol, 2010; Mauvezin et. al., EMBO Rep, 2010; Nowak et. al., Mol Biol Cell, 2009). This is why we decided to analyze which of these two functions could explain the phenotype observed in our mice models. In this regard, we performed a transcriptomic analysis using microarrays looking for genes differentially expressed in the quadriceps muscle of WT and SKM-Tg mice as well as in C and SKM-KO animals. Surprisingly, only a reduced number of genes were dysregulated upon DOR manipulation and most of the genes underwent mild changes in expression. These data strongly suggest that DOR does not operate as a nuclear co-factor in mouse skeletal muscle under the conditions subjected to study. In contrast, DOR enhances basal autophagy in skeletal muscle and promotes muscle wasting when autophagy is a contributor to muscle loss. To determine the functional role of DOR in skeletal muscle, we generated transgenic mice (SKM-Tg) overexpressing DOR specifically in skeletal muscle under the Myosin-Light Chain 1 promoter/enhancer. The open reading frame of DOR was introduced in an EcoRI site in the MDAF2 vector, which contains a 1.5 kb fragment of the MLC1 promoter and 0.9 kb fragment of the MLC1/3 gene containing a 3' muscle enhancer element (Rosenthal et. al., PNAS, 1989; Otaegui et. al., FASEB J, 2003). The fragment obtained after the digestion of this construct with BssHII was the one used to generate both transgenic mouse lines. Nontransgenic littermates were used as controls for the transgenic animals (Wt). In addition, a muscle-specific DOR knock-out mouse line (SKM-KO) was also generated by crossing homozygous DOR loxP/loxP mice with a mouse strain expressing Cre recombinase under the control of the Myosin-Light Chain 1 promoter (Bothe et. al., Genesis, 2000). Deletion of exons 3 and 4 driven by Cre recombinase caused the ablation of DOR expression. Non-expressing Cre DOR loxP/loxP littermates were used as controls for knockout animals (C). Four-month-old male mice were used in all experiments. Mice were in a C57BL/6J pure genetic background. We used microarrays to analyze the effect of DOR gain-of-function and DOR ablation on skeletal muscle gene expression Total RNA from quadriceps muscles from 4-month-old male mice was extracted and used for hibridization on Affimetrix microarrays
Project description:We analyzed the functional role of DOR (Diabetes and Obesity Regulated gene) (also named Tp53inp2) in skeletal muscle. We show that DOR has a direct impact on skeletal muscle mass in vivo. Thus, using different transgenic mouse models, we demonstrate that while muscle-specific DOR gain-of-function results in reduced muscle mass, loss-of-function causes muscle hypertrophy. DOR has been described as a protein with two different functions, i.e., a nuclear coactivator and an autophagy regulator (Baumgartner et. al., PLoS One, 2007; Francis et. al., Curr Biol, 2010; Mauvezin et. al., EMBO Rep, 2010; Nowak et. al., Mol Biol Cell, 2009). This is why we decided to analyze which of these two functions could explain the phenotype observed in our mice models. In this regard, we performed a transcriptomic analysis using microarrays looking for genes differentially expressed in the quadriceps muscle of WT and SKM-Tg mice as well as in C and SKM-KO animals. Surprisingly, only a reduced number of genes were dysregulated upon DOR manipulation and most of the genes underwent mild changes in expression. These data strongly suggest that DOR does not operate as a nuclear co-factor in mouse skeletal muscle under the conditions subjected to study. In contrast, DOR enhances basal autophagy in skeletal muscle and promotes muscle wasting when autophagy is a contributor to muscle loss. To determine the functional role of DOR in skeletal muscle, we generated transgenic mice (SKM-Tg) overexpressing DOR specifically in skeletal muscle under the Myosin-Light Chain 1 promoter/enhancer. The open reading frame of DOR was introduced in an EcoRI site in the MDAF2 vector, which contains a 1.5 kb fragment of the MLC1 promoter and 0.9 kb fragment of the MLC1/3 gene containing a 3' muscle enhancer element (Rosenthal et. al., PNAS, 1989; Otaegui et. al., FASEB J, 2003). The fragment obtained after the digestion of this construct with BssHII was the one used to generate both transgenic mouse lines. Nontransgenic littermates were used as controls for the transgenic animals (Wt). In addition, a muscle-specific DOR knock-out mouse line (SKM-KO) was also generated by crossing homozygous DOR loxP/loxP mice with a mouse strain expressing Cre recombinase under the control of the Myosin-Light Chain 1 promoter (Bothe et. al., Genesis, 2000). Deletion of exons 3 and 4 driven by Cre recombinase caused the ablation of DOR expression. Non-expressing Cre DOR loxP/loxP littermates were used as controls for knockout animals (C). Four-month-old male mice were used in all experiments. Mice were in a C57BL/6J pure genetic background.
Project description:C57Bl6 mice were subjected to cecal-ligation and puncture or sham surgery. Mice were sacrificed after 24 h or 96 h and muscle tissue was harvested. RNA from tibialis anterior muscle was isolated and subjected to RNA sequencing.
Project description:Identfification of MEF2A target genes using ChIP-exo in skeletla muscle and primary cardiomyocytes. Identfification of MEF2A target genes using ChIP-exo and RNA-seq in skeletal muscle and primary cardiomyocytes. MEF2 plays a profound role in the regulation of transcription in cardiac and skeletal muscle lineages. To define the overlapping and unique MEF2A genomic targets, we utilized ChIP-exo analysis of cardiomyocytes and skeletal myoblasts. Of the 2783 and 1648 MEF2A binding peaks in skeletal myoblasts and cardiomyocytes, respectively, 294 common binding sites were identified. Genomic targets were compared to differentially expressed genes in RNA-seq analysis of MEF2A depleted myogenic cells.