Replacing skeletal muscle alpha-actin with cardiac actin in mouse skeletal muscle
ABSTRACT: Skeletal muscle actin mice (Crawford et al., (2002) Mol Cell Biol 22, 5587) were crossed with cardiac actin transgenic mice (termed "ACTC^Coco" or "Coco" for short), to produce mice that had cardiac actin instead of skeletal muscle actin in their skeletal muscles (termed "ACTC^Co/KO" or for short "Coco/KO"). Microarray analysis using the Illumina mouse-6 v1.1 expression beadchip was performed on RNA extraced from the soleus muscle of Coco/KO mice and wildtype mice, to confirm the swith in actin isoform expression, and to determine what other differences might exist between wildtype mice and the Coco/KO mice. Keywords: genetic modification 3 RNA samples (each being the pool of two individual samples extracted from different soleus muscles from different individual mice) per genotype (either wildtype or Coco/KO) were used. The total 6 RNA samples were processed using an Illumina mouse-6 v1.1expression beadchip and then the differentially expressed genes determined.
Skeletal muscle alpha-actin (ACTA1) is the major actin in postnatal skeletal muscle. Mutations of ACTA1 cause mostly fatal congenital myopathies. Cardiac alpha-actin (ACTC) is the major striated actin in adult heart and fetal skeletal muscle. It is unknown why ACTC and ACTA1 expression switch during development. We investigated whether ACTC can replace ACTA1 in postnatal skeletal muscle. Two ACTC transgenic mouse lines were crossed with Acta1 knockout mice (which all die by 9 d after birth). Off ...[more]
Project description:Skeletal muscle actin mice (Crawford et al., (2002) Mol Cell Biol 22, 5587) were crossed with cardiac actin transgenic mice (termed "ACTC^Coco" or "Coco" for short), to produce mice that had cardiac actin instead of skeletal muscle actin in their skeletal muscles (termed "ACTC^Co/KO" or for short "Coco/KO"). Microarray analysis using the Illumina mouse-6 v1.1 expression beadchip was performed on RNA extraced from the soleus muscle of Coco/KO mice and wildtype mice, to confirm the swith in actin isoform expression, and to determine what other differences might exist between wildtype mice and the Coco/KO mice. Keywords: genetic modification Overall design: 3 RNA samples (each being the pool of two individual samples extracted from different soleus muscles from different individual mice) per genotype (either wildtype or Coco/KO) were used. The total 6 RNA samples were processed using an Illumina mouse-6 v1.1expression beadchip and then the differentially expressed genes determined.
Project description:Male skeletal muscles are generally faster and have a higher maximum power output than female muscles. Conversely, during repeated contractions female muscles sre generally more fatigue resistant and recover faster. we hypothesized that estrogen receptor beta is involved in this gender difference. The Affymetrix micorarray were used to deteced the differently expressed genes between male BERKO and WT mice in soleus muscles. Soleus muscles from 3 individual mouse of each genotype were used to perform the experiment.
Project description:Determination of gene expression changes in extraocular and hindlimb (gastrocnemius/soleus) of mdx (dystrophin-deficient) mice at postnatal day 56. 5 independent replicates/muscle group/strain.
Project description:The myogenic regulatory factor MRF4 is expressed at high levels in myofibers of adult skeletal muscle, but its function is unknown. Here we show that knockdown of MRF4 in adult muscle causes hypertrophy and prevents denervation-induced atrophy. This effect is accompanied by increased protein synthesis and the widespread activation of genes involved in muscle contraction, excitation-contraction coupling and energy metabolism, many of which are known targets of MEF2 transcription factors. Genes regulated by MEF2 represent the top-ranking gene set enriched after Mrf4 RNAi, and a MEF2 reporter is inhibited by co-transfected MRF4 and activated by Mrf4 RNAi. The role of MEF2 in mediating the effect of MRF4 knockdown is supported by the finding that Mrf4 RNAi-dependent increase in fiber size is prevented by dominant negative MEF2, while constitutively active MEF2 is able to induce myofiber hypertrophy. The nuclear localization of the MEF2 co-repressor HDAC4 is impaired by Mrf4 knockdown, suggesting that MRF4 acts by stabilizing a repressor complex that controls MEF2 activity. The demonstration that fiber size in adult skeletal muscle is controlled by the MRF4-MEF2 axis opens new perspectives in the search for therapeutic targets to prevent muscle wasting, in particular sarcopenia and cachexia. Adult innervated and denervated rat soleus muscles were transfected with shRNA to Mrf4 (M1) or to LacZ as a control. Muscles were dissected and examined after 7 days. For each group/condition we selected three different muscles (biological replicas).
Project description:To compare the microRNAs (miRNAs) expression profile in the innervated soleus muscle and L4-L6 DRG neuronsafter sciatic nerve entrapment with a non-constrictive silastic tube, subsequent surgical decompression, and denervation injury. The experimental soleus muscles and dorsal root ganglions (DRGs) from each experimental group (sham control, denervation, entrapment, and decompression) were analyzed with an Agilent® rat miRNA array to detect dysregulated miRNAs Three-condition experiment, DRGs and soleus muscles of the rats receiving sciatic nerve denervation 6 months, sciatic nerve entrapment 6 months, and sciatic nerve entrapment 6 months then decompression for 3 months v.s. soleus muscle (sham control), Biological replicates: 1 control replicates, 3 experiment replicates
Project description:Comparison of normal adult rat extraocular muscle, cardiac muscle, leg (gastrocnemius-soleus) muscle and smooth muscle (stomach wall). Affymetrix microarray chip RG-U34A was used. MAS version 5 was used to analyze the muscle group differences. Data form part of publication: FASEB Journal 17: 1370-1372, 2003 (full length article available at http://www.fasebj.org/cgi/doi/10.1096/fj.02-1108fje).
Project description:Muscle denervation due to injury, disease or aging results in impaired motor function. Restoring neuromuscular communication requires axonal regrowth and regeneration of neuromuscular synapses. Muscle activity inhibits neuromuscular synapse regeneration. The mechanism by which muscle activity regulates regeneration of synapses is poorly understood. Dach2 and Hdac9 are activity-regulated transcriptional co-repressors that are highly expressed in innervated muscle and suppressed following muscle denervation. Here, we report that Dach2 and Hdac9 inhibit regeneration of neuromuscular synapses. Importantly, we identified Myog and Gdf5 as muscle-specific Dach2/Hdac9-regulated genes that stimulate neuromuscular regeneration in denervated muscle. Interestingly, Gdf5 also stimulates presynaptic differentiation and inhibits branching of regenerating neurons. Finally, we found that Dach2 and Hdac9 suppress miR206 expression, a microRNA involved in enhancing neuromuscular regeneration. RNAseq on innervated and 3 day denervated adult soleus muscle from wildtype mice is compared with that from 3 day denervated soleus muscle from Dach2/Hdac9 deleted mice to identify Dach2/Hdac9-regulated genes.
Project description:Analysis of integrin alpha7 transgenic mice skeletal muscle transcription profiles comparing to wild type controls. Integrin alpha7 is the major laminin binding integrin in muscle cells. Enhancing its expression has been demonstrated to alleviate pathology in a murine model of Duchenne muscular dystrophy. Results of this study provide insights into the effects of increasing integrin alpha7 expression on skeletal muscle transcription and physiology in vivo. This analysis also evaluates any potential possible side effects associate with enhancing integrin alpha7 in skeletal muscle. Experiment Overall Design: Equal amount of total RNA from six animals of each genotype were pooled to generate a biological replicate. Total of three biological replicates were used. Together, 18 mice of each genotype were used in this analysis.