Transcriptome-wide RNA sequencing analysis of rat skeletal muscle feed arteries. II. Impact of exercise training in obesity

Abstract

We employed next-generation RNA sequencing (RNA-Seq) technology to determine the extent to which exercise training alters global gene expression in skeletal muscle feed arteries and aortic endothelial cells of obese Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Transcriptional profiles of the soleus and gastrocnemius muscle feed arteries (SFA and GFA, respectively) and aortic endothelial cell-enriched samples from rats that underwent an endurance exercise training program (EndEx; n = 12) or a interval sprint training program (IST; n = 12) or remained sedentary (Sed; n = 12) were examined. In response to EndEx, there were 39 upregulated (e.g., MANF) and 20 downregulated (e.g., ALOX15) genes in SFA and 1 upregulated (i.e., Wisp2) and 1 downregulated (i.e., Crem) gene in GFA [false discovery rate (FDR) < 10%]. In response to IST, there were 305 upregulated (e.g., MANF, HSPA12B) and 324 downregulated genes in SFA and 101 upregulated and 66 downregulated genes in GFA, with an overlap of 32 genes between arteries. Furthermore, in aortic endothelial cells, there were 183 upregulated (e.g., eNOS, SOD-3) and 141 downregulated (e.g., ATF3, Clec1b, npy, leptin) genes with EndEx and 71 upregulated and 69 downregulated genes with IST, with an overlap of 35 between exercise programs. Expression of only two genes (Tubb2b and Slc9a3r2) was altered (i.e., increased) by exercise in all three arteries. The finding that both EndEx and IST produced greater transcriptional changes in the SFA compared with the GFA is intriguing when considering the fact that treadmill bouts of exercise are associated with greater relative increases in blood flow to the gastrocnemius muscle compared with the soleus muscle.

Transcriptomic effects of metformin in skeletal muscle arteries of obese insulin-resistant rats

“…29 In keeping with the theme that systemic interventions can produce heterogeneous spatial distribution of vascular transcriptomic effects throughout the arterial vasculature, the findings from the present study are especially remarkable. Herein we provide evidence that pharmacological treatment also evokes heterogeneous effects across the arterial tree with contrasting vascular effects not only observed between muscles but also within muscle, thus resembling our prior findings on the effects of exercise [15][16][17]27 and obesity. 24,28,29 Fundamentally, these data support the idea that regulation of vascular gene expression in response to a given insult (e.g.…”

“…17,23 RNA extraction, RNA quality control, library preparation, and RNA-seq were performed as described previously. 16,24 …”

“…13 As in previous studies from our group, lack of changes in vasomotor function in response to an intervention does not imply an absence of a vascular phenotypic effect at the molecular level. [15][16][17] As such, to gain further insights into the impact of metformin on the vasculature, we assessed transcriptional profiles in skeletal muscle resistant arteries from the OLETF rats utilized in our previous study. 13 Specifically, we performed a transcriptome-wide RNA sequencing (RNASeq) analysis in the feed arteries and second branch order arterioles in the soleus, gastrocnemius, and diaphragm muscles in metformin-treated (via drinking water for 12 weeks) versus untreated OLETF rats.…”

Vascular dysfunction in obesity: Beneficial effects of aerobic exercise training in animal models

“…However, it should be noted that exercise intensity seems to be a crucial variable in this response. A recent study evaluated the impact of exercise training on vascular gene expression profiles, using a transcriptome-wide RNA-Seq analysis in obese rats 41 . In particular, the analysis was performed on the soleus and gastrocnemius muscle feed arteries (SFA and GFA, respectively) and aortic endothelial cell-enriched samples from obese Otsuka Long-Evans Tokushima Fatty (OLETF) rats that underwent an endurance exercise training program (EndEx) or interval sprint training program (IST).…”

Identification of genes whose expression is altered by obesity throughout the arterial tree

“…Total RNA isolations were performed by the NucleoMag 96 RNA kit procedure (Clontech part #744350.1), as described in detail previously (22,32). All liquid handling was optimized for use on a Beckman3000 robotic liquid handler housed within a laminar flow hood (with UV decontamination) designed to ensure a clean room environment for working with microtissues that yield low (pg to ng) amounts of RNA.…”