The α7β1 integrin accelerates exercise-induced myogenesis

Lueders, Tara N.

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https://hdl.handle.net/2142/16000 Copy

Description

Title

The α7β1 integrin accelerates exercise-induced myogenesis

Author(s)

Lueders, Tara N.

Issue Date

2010-05-18T18:55:41Z

Director of Research (if dissertation) or Advisor (if thesis)

Boppart, Marni D.

Department of Study

Kinesiology & Community Health

Discipline

Kinesiology

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• myogenesis
• eccentric exercise
• alpha7beta1 integrin
• mesenchymal-like stem cells
• Sca-1+
• CD45-

Abstract

Muscle-specific transgenic overexpression of the α7β1 integrin can protect against exercise induced-injury and promote the appearance of multipotent mesenchymal-like (Sca-1+CD45-) stem cells in skeletal muscle. PURPOSE: The purpose of this study was to determine if overexpression of the α7β1 integrin also results in enhanced and/or accelerated myogenesis following a single bout of eccentric exercise. METHODS: 5-wk old, female wild type (WT) and α7 integrin transgenic (α7Tg) mice completed a single bout of downhill running exercise (-20o, 17 m/min, 60 min) and gastrocnemius-soleus complexes were collected 2, 4, and 7 d post-exercise. Myogenesis was quantified using embryonic myosin heavy chain (eMHC) expression and the presence of centrally located nuclei (CLN). RESULTS: Whereas gradual increases in eMHC expression were detected in WT mice following exercise, a 5-fold increase in eMHC+ fibers was present at 2 d post-exercise in α7Tg mice compared to α7Tg mice that did not exercise (P < 0.001). Consistent with this adaptation, WT mice had gradual increases in numbers of CLN until 7 d post-exercise, whereas α7Tg mice had a 5-fold increase in CLN levels at 2 d post-exercise (P<0.001). CONCLUSION: This study suggests that the protection from injury and increased appearance of mesenchymal stem cells observed with α7β1 integrin overexpression may directly or indirectly contribute to accelerated myogenesis following eccentric exercise. This study provides the first evidence that the α7β1 integrin participates in myogenesis acceleration.

Graduation Semester

2010-5

Permalink

http://hdl.handle.net/2142/16000

Copyright and License Information

Copyright 2010 Tara N. Lueders

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