The effects of low level laser therapy on satellite cells

[摘要] ENGLISH ABSTRACT: Although muscle tissue demonstrates a remarkable capacity for regenerationfollowing injury, this process is slow and often accompanied by the formationof scar tissue and a subsequent decrease in contractile capacity followingregeneration. Treatment options are few and mostly supportive in nature.This regeneration process involves muscle stem cells (satellite cells) whichultimately give rise to the regenerated muscle.The contentious field of low level laser therapy (LLLT) has made remarkableclaims in facilitating wound healing in soft tissue injuries of various types. Yet,the mechanism(s) invoked in these beneficial effects are poorly understood.We have investigated the effects of LLLT using a 638 nm laser on satellitecells in culture and in-vivo. Using an array of techniques we have measured,amongst other things, metabolic responses to laser irradiation, signalingpathways activated/altered and antioxidant status.In response to laser irradiation satellite cells in culture showed an increase inMTT values (a measure of metabolic activity) and a decrease in antioxidantstatus (measured using the ORAC assay). In addition laser irradiation alsoaltered the expression and phosphorylation state of several signalingpathways, including Akt and STAT-3.Following on from this the effects of laser irradiation on satellite cells in-vivowas assessed in a rat model of contusion injury. No significant differences insatellite cell number was found following laser irradiation, changes were seenin tissue antioxidant status and blood antioxidant status (measured using theORAC assay).In the course of this study several standard techniques were used toinvestigate the effects of laser irradiation on satellite cells both in-vitro and invivo.It has become apparent that several of these techniques haveproblems associated with them that possibly make them inappropriate forvifurther use in studies involving laser irradiation. However the results indicatethat laser therapy is induces satellite cell behavior and further study iswarranted in this field.

[发布机构] Stellenbosch University