Skeletal muscle atrophy is a consequence of many diseases, environmental insults, inactivity, age and injury. Atrophy is characterized by active degradation and removal of contractile proteins and a reduction in fiber size. Animal models have been extensively used to identify pathways leading to atrophic conditions. Here we have used genome-wide expression profiling analysis and quantitative PCR to identify the molecular changes that occur in two clinically relevant animal mouse models of muscle atrophy, hindlimb casting and Achilles tendon laceration (tenotomy). Gastrocnemius muscle samples were collected 2, 7 and 14 days after insult. The total amount of muscle loss as measured by wet weight and muscle fiber size was equivalent between models, although tenotomy resulted in a more rapid induction of muscle atrophy. Furthermore, tentomy resulted in the regulation of significantly more mRNA transcripts then casting. Analysis of the regulated genes and pathways suggest that the mechanism of atrophy is distinct between these models. The degradation following casting appears ubiquitin-proteasome-mediated while degradation following tenotomy appears lysosomal and matrix-metalloproteinase (MMP)-mediated. This data suggests that there are multiple mechanisms leading to muscle atrophy and that specific therapeutic agents may be necessary to combat the atrophy seen under different conditions.
Distinct protein degradation profiles are induced by different disuse models of skeletal muscle atrophy.
Sex, Specimen part, Treatment, Time
View SamplesGene expression profiling was carried out on splenocyte mRNA samples collected from 10 animals subject to repeated social threat (pooled into 2 groups of 5) and 10 animals subject to non-threatening control conditions (pooled into 2 groups of 5). The primary research question is whether gene expression differs in CD11b+ splenocytes from animals exposed to social threat vs non-threatening control conditions.
Computational identification of gene-social environment interaction at the human IL6 locus.
Specimen part
View SamplesComparison of mRNA expression from FACS isolated Gli1 expressing stromal cells from mice given SAG21k versus vehicle
Control of inflammation by stromal Hedgehog pathway activation restrains colitis.
Sex, Specimen part, Treatment
View SamplesWe compared the aorta of 6-weeks-old mice (young) with 18-months-old mice (old). Using the publicly available tools Sylamer and DIANA-mirExTra, we identified an enrichment for miR-29 binding sites in the 3'UTR of genes downregulated in the aged aortas. We subsequently showed that inhibition of miR-29 in aged mice prevented dilation of the aorta.
MicroRNA-29 in aortic dilation: implications for aneurysm formation.
Age, Specimen part
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