Expression data from normal weight/obese and sham/injured female C57BL/6J mice

Injury of skeletal muscle is a common occurence affecting millions worldwide. Injuries usually are not major incisions into daily life, however, the underlying health varies e. g. due to obesity. Obesity is usually accompanied by excessive and dysfunctional lipid depots, chronic low-grade inflammation as well as several co-morbidities, which are able to impair the regeneration of skeletal muscle. A blunt injury approach was used to damage mouse skeletal muscle of the extensor iliotibialis anticus in both obese and normal weight C57BL/6J mice. Microarray analysis was used to assess the molecular fingerprint in different stages of muscle regeneration while observing different health conditions. Muscle tissue from extensor iliotibialis anticus of normal weight and obese female mice, control and injury (n = 3). Harvesting time points were 1h, 6h, 24h, 3d and 8d to cover the early and middle stage regeneration process. Isolation of total RNA with subsequent microarray analysis performed with the Affymetrix system. 100 ng RNA per sample were used as described in the GeneChip® WT PLUS Reagent Kit from Affymetrix. Mouse Gene 1.0 ST Array GeneChip was used. Analysis of arrays was carried out with Affymetrix GeneChip Scanner 3000 and evaluated using Affymetrix Expression Console™. Evaluation of the CEL files was designed in R with RStudio. Briefly, injured versus control animals were normalized by RMA fit for time and diet, respectively. Pval function was used to determine p-values. Regulation of genes was first assessed without consideration for significance or expression levels to develop an unbiased time lapse heatmap. Significance level p ≤ 0.05 was introduced to screen for differentially expressed genes (DEG).