Skeletal muscle pericyte response to acute and chronic electrical stimulation

Pericytes are mural cells that are located on the outer surface of blood capillaries where they attach to endothelial cells and regulate vascular function, including dilation and angiogenesis. Recent studies suggest that pericytes in skeletal muscle may contribute to myofiber repair in response to injury. However, the pericyte response to exercise remains largely unexplored. PURPOSE: The purpose of this study was to evaluate pericyte quantity and gene expression in skeletal muscle following electrical stimulation, a method that can be used to simulate resistance exercise in mice. METHODS: Adult wild-type mice were subjected to an electrical stimulation protocol that results in 20 eccentric and 20 concentric contractions during a single session or (n=5; n=4 sham). A separate cohort of mixed-sex mice were subjected to electrical stimulation twice weekly for 4 weeks (n=4; n=4 sham) and 9 weeks (n=3; n=3 sham). At the end of each study, gastrocnemius-soleus complexes were dissected 24h following the final bout of stimulation. Pericyte quantity was assessed by multiplex flow cytometry in all samples. NG2+CD45-CD31- and CD146+CD45-CD31- pericytes were isolated following the acute study and gene expression was evaluated using high throughput qPCR. RESULTS: Acute electrical stimulation resulted in a non-significant trend for an increase in total pericyte content in skeletal muscle and a significant increase in the percentage of NG2+CD45-CD31- pericytes expressing the mesenchymal stem/stromal cell (MSC) marker CD140A. Isolation of pericytes based on CD146 revealed a population of cells highly engaged in the synthesis of factors necessary for myogenesis, satellite cell activation, and extracellular matrix remodeling post-acute stimulation. Finally, a pericyte to MSC transition was also observed with 4 weeks of stimulation, but no changes in overall pericyte quantity were noted at 4 or 9 weeks. CONCLUSION: This study provides evidence that resistance exercise promotes a pericyte to MSC transition, an event that may be necessary for pericytes to engage in skeletal muscle repair and adaptation.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Kinesiology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2016

Author dc:creator

• Dvoretskiy, Svyatoslav Victorovich

Contributors dc:contributor

• Boppart, Marni D.

• Pericyte
• Electrical Stimulation
• Skeletal Muscle

Statement dc:rights

• Copyright 2016 Svyatoslav Dvoretskiy

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/90920

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/90920