Exp Mol Med.  2010 Sep;42(9):614-627. 10.3858/emm.2010.42.9.061.

TRPC3 cation channel plays an important role in proliferation and differentiation of skeletal muscle myoblasts

• Woo JS
• Cho CH
• Kim DH
• Lee EH

• KMID: 983954
• DOI: http://doi.org/10.3858/emm.2010.42.9.061

Abstract

During membrane depolarization associated with skeletal excitation-contraction (EC) coupling, dihydropyridine receptor [DHPR, a L-type Ca2+ channel in the transverse (t)-tubule membrane] undergoes conformational changes that are transmitted to ryanodine receptor 1 [RyR1, an internal Ca2+-release channel in the sarcoplasmic reticulum (SR) membrane] causing Ca2+ release from the SR. Canonical-type transient receptor potential cation channel 3 (TRPC3), an extracellular Ca2+-entry channel in the t-tubule and plasma membrane, is required for full-gain of skeletal EC coupling. To examine additional role(s) for TRPC3 in skeletal muscle other than mediation of EC coupling, in the present study, we created a stable myoblast line with reduced TRPC3 expression and without alpha1SDHPR (MDG/TRPC3 KD myoblast) by knock-down of TRPC3 in alpha1SDHPR-null muscular dysgenic (MDG) myoblasts using retrovirus-delivered small interference RNAs in order to eliminate any DHPR-associated EC coupling-related events. Unlike wild-type or alpha1SDHPR-null MDG myoblasts, MDG/TRPC3 KD myoblasts exhibited dramatic changes in cellular morphology (e.g., unusual expansion of both cell volume and the plasma membrane, and multi-nuclei) and failed to differentiate into myotubes possibly due to increased Ca2+ content in the SR. These results suggest that TRPC3 plays an important role in the maintenance of skeletal muscle myoblasts and myotubes.

Keyword

calcium channel; dihydropyridine receptor; MG29; Orai1; ryanodine receptor; TRPC3 cation channel; TRPC4 cation channel

MeSH Terms

Animals
Calcium/metabolism
Calcium Channels/metabolism
Calcium Channels, L-Type/genetics/metabolism
Cations/metabolism
*Cell Differentiation
*Cell Proliferation
Cells, Cultured
Excitation Contraction Coupling
Gene Knockdown Techniques
Membrane Potentials
Mice
Muscle Fibers, Skeletal/*metabolism
Muscle Proteins/metabolism
Myoblasts, Skeletal/*metabolism
Ryanodine Receptor Calcium Release Channel/metabolism
Sarcoplasmic Reticulum/*physiology
Synaptophysin/metabolism
TRPC Cation Channels/genetics/*metabolism
Transient Receptor Potential Channels/metabolism