title: Macrophage depletion impairs skeletal muscle regeneration: The roles of regulatory factors for muscle regeneration.
abstract: Though macrophages are essential for skeletal muscle regeneration, which is a complex process, the roles and mechanisms of the macrophages in the process of muscle regeneration are still not fully understood. The objective of this study is to explore the roles of macrophages and the mechanisms involved in the regeneration of injured skeletal muscle. One hundred and twelve C57BL/6 mice were randomly divided into muscle contusion and macrophages depleted groups. Their gastrocnemius muscles were harvested at the time points of 12 h, 1, 3, 5, 7, 14 d post-injury. The changes in skeletal muscle morphology were assessed by hematoxylin and eosin (HE) stain. The gene expression was analyzed by real-time polymerase chain reaction. The data showed that CL-liposomes treatment did affect the expression of myogenic regulatory factors (MyoD, myogenin) after injury. In addition, CL-liposomes treatment decreased the expression of regulatory factors of muscle regeneration (HGF, uPA, COX-2, IGF-1, MGF, FGF6) and increased the expression of inflammatory cytokines (TGF-β1, TNF-α, IL-1β, RANTES) in the late stage of regeneration. Moreover, there were significant correlations between macrophages and some regulatory factors (such as HGF, uPA) for muscle regeneration. These results suggested that macrophages depletion impairs skeletal muscle regeneration and that the regulatory factors for muscle regeneration may play important roles in this process.
authors.affiliation: School of Kinesiology, Shanghai University of Sport, Shanghai, 200438, China.
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Liu
authors.affiliation: School of Kinesiology, Shanghai University of Sport, Shanghai, 200438, China.|Department of Exercise Science, Shenyang Sport University, Shenyang, 110001, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Kinesiology, Shanghai University of Sport, Shanghai, 200438, China.
authors.forename: Linlin
authors.initials: L
authors.lastname: Zhao
authors.affiliation: School of Kinesiology, Shanghai University of Sport, Shanghai, 200438, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zeng
authors.affiliation: School of Kinesiology, Shanghai University of Sport, Shanghai, 200438, China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Xiao
authors.affiliation: School of Kinesiology, Shanghai University of Sport, Shanghai, 200438, China.
authors.forename: Peijie
authors.initials: P
authors.lastname: Chen
mesh_terms: D000818:Animals; D004002:Clodronic Acid / Q000633:toxicity; D008264:Macrophages / Q000187:drug effects / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000187:drug effects / Q000502:physiology*; D018006:Myogenic Regulatory Factors / Q000502:physiology*; D011897:Random Allocation; D012038:Regeneration / Q000187:drug effects / Q000502:physiology*
chemical_list: D018006:Myogenic Regulatory Factors; D004002:Clodronic Acid
keywords: inflammatory cytokines; macrophages; regeneration; regulatory factors; satellite cells; skeletal muscle