Effect of Low Power Laser Irradiation on the Ability of Cell Growth and Myogenic Differentiation of Myoblasts CulturedIn Vitro

Cui-Ping Zhang,Xiao-Ying Wang,Peng Chen,Xiao-Bing Fu,Shao-Dan Li,Hong-Xiang Kang,Jie Liang,Chang-Zhen Wang,Ben-Jian Shen

doi:10.1155/2014/290765

Abstract

As a therapeutic modality, low power laser irradiation (LPLI) has been used clinically in the treatment of skeletal muscle injuries and other myopathic conditions, but the cellular and molecular mechanisms attributed to this therapy were still unclear. Myoblasts are a type of myogenic stem cells quiescence in mature skeletal muscle fibers and are considered as the source cells during the regenerating process. The purpose of this paper was to investigate the effects of LPLI on the proliferation and myogenic differentiation of the cultured myoblasts and to find out the major candidates responsible for LPLI-induced muscle regenerationin vivo. In this study, primary rat myoblasts were exposed to helium-neon (He-Ne) laser. Cell proliferation, differentiation, and the cellular responses to LPLI were monitored by using morphological observation and molecular biological methods. It was found that LPLI at a certain fluence could increase the cell growth potential for myoblasts and further induce more cells entering into S phase of the mitotic cycle as indicated by high levels of bromodeoxyuridine (BrdU) incorporation, while at the same time inhibiting theirin vitrodifferentiation and decreasing the expression of myogenic regulatory genes to a certain extent. Taken together, these results provide experimental evidence for the clinical applications of LPLI in regenerating skeletal muscle.

Highlights

The primary functions of skeletal musculature are locomotor activity, postural behavior, and breathing
Recent in vivo studies have showed that, following low power laser irradiation (LPLI), the injured skeletal muscle recovered much faster and survived longer than unirradiated tissues, indicating that LPLI can be utilized for muscle physiological regeneration and functional reconstitution [9]; the cellular and molecular mechanisms of the laser-induced photobiomodulation attributed to this therapy are still unclear
Myoblasts in control group were induced to differentiate into multinucleated myotubes by switching to differentiation culture media; the myotube formation could be inhibited to a certain extent by 3 min laser irradiation

Summary

Introduction

The primary functions of skeletal musculature are locomotor activity, postural behavior, and breathing. Skeletal muscle is susceptible to injury after direct trauma or resulting from indirect causes, such as neurological dysfunction or innate genetic defects [1]. If left unrepaired, these injuries may lead to loss of muscle mass, locomotive deficiency, and in the worse cases lethality. LPLI has achieved positive effects in clinical treatment of wound healing, chronic pain relief, periodontal disease, and fracture rehabilitation [5,6,7,8]. Recent in vivo studies have showed that, following LPLI, the injured skeletal muscle recovered much faster and survived longer than unirradiated tissues, indicating that LPLI can be utilized for muscle physiological regeneration and functional reconstitution [9]; the cellular and molecular mechanisms of the laser-induced photobiomodulation attributed to this therapy are still unclear

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