Analysis of gene transcription in response to an acute bout of exercise identifies dysregulation of SMAD, CREB, and HDAC activity
in LRT. RNA was extracted from the soleus muscles of rats under resting conditions or 3 h after an acute bout of treadmill
running exercise. Genes that were significantly upregulated (red) or downregulated (blue) in response to exercise in LRT/HRT
were identified using Affymetrix Rat ST 1.0 chips and analyzed using ingenuity pathway analysis (IPA; false discovery rate
[FDR] = 5%, no fold-change filter). Transcription factor analysis in IPA clearly identified activation of SMAD3 (Z score = 2.3; P = 1.1 × 10–7) and CREB1 (Z score = 2.1; P = 6.7 × 10–6) target genes, whereas HDAC-regulated genes were inhibited (Z score = −2.8; P = 1.1 × 10–7) in response to exercise in LRT. Direct transcription factor/target gene relationships are indicated by solid arrows, and
indirect relationships are indicated by broken arrows. No transcription factor enrichment was found in the HRT-regulated gene
list, which was a set of entirely upregulated genes (n = 156, FDR = 5%, no fold-change filter) that bore no ontological or pathway overlap with the LRT dataset in IPA. n = 5–6 chips/group.