title: Irisin promotes osteoblast proliferation and differentiation via activating the MAP kinase signaling pathways.
abstract: Physical exercise is able to improve skeletal health. However, the mechanisms are poorly known. Irisin, a novel exercise-induced myokine, secreted by skeletal muscle in response to exercise, have been shown to mediate beneficial effects of exercise in many disorders. In the current study, we demonstrated that irisin promotes osteoblast proliferation, and increases the expression of osteoblastic transcription regulators, such as Runt-related transcription factor-2, osterix/sp7; and osteoblast differentiation markers, including alkaline phosphatase, collagen type 1 alpha-1, osteocalcin, and osteopontin in vitro. Irisin also increase ALP activity and calcium deposition in cultured osteoblast. These osteogenic effects were mediated by activating the p38 mitogen-activated protein kinase (p-p38 MAPK) and extracellular signal-regulated kinase (ERK). Inhibition of p38 MAPK by SB023580 or pERK by U0126 abolished the proliferation and up-regulatory effects of irisin on Runx2 expression and ALP activity. Together our observation suggest that irisin directly targets osteoblast, promoting osteoblast proliferation and differentiation via activating P38/ERK MAP kinase signaling cascades in vitro. Whether irisin can be utilized as the therapeutic agents for osteopenia and osteoporosis is worth to be further pursued.
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Qiao
authors.affiliation: Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, People's Republic of China.|The Joint Laboratory for Reproductive Medicine of Sichuan University-The Chinese University of Hong Kong, People's Republic of China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Yong Qiao
authors.affiliation: Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, People's Republic of China.|The Joint Laboratory for Reproductive Medicine of Sichuan University-The Chinese University of Hong Kong, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Nie
authors.forename: Yaxian
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, People's Republic of China.|The Joint Laboratory for Reproductive Medicine of Sichuan University-The Chinese University of Hong Kong, People's Republic of China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Xian Ma
authors.affiliation: Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, People's Republic of China.|The Joint Laboratory for Reproductive Medicine of Sichuan University-The Chinese University of Hong Kong, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, People's Republic of China.|The Joint Laboratory for Reproductive Medicine of Sichuan University-The Chinese University of Hong Kong, People's Republic of China.
authors.forename: Ran
authors.initials: R
authors.lastname: Cheng
authors.forename: Weiyao
authors.initials: W
authors.lastname: Yin
authors.affiliation: Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, People's Republic of China.|The Joint Laboratory for Reproductive Medicine of Sichuan University-The Chinese University of Hong Kong, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yao Yinrg
authors.affiliation: Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, People's Republic of China.|The Joint Laboratory for Reproductive Medicine of Sichuan University-The Chinese University of Hong Kong, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Hu
authors.forename: Wenming
authors.initials: W
authors.lastname: Xu
authors.affiliation: The Joint Laboratory for Reproductive Medicine of Sichuan University-The Chinese University of Hong Kong, People's Republic of China.
authors.forename: Wen
authors.initials: W
authors.lastname: Ming Xu
authors.affiliation: Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, People's Republic of China.|The Joint Laboratory for Reproductive Medicine of Sichuan University-The Chinese University of Hong Kong, People's Republic of China.
authors.forename: Liangzhi
authors.initials: L
authors.lastname: Xu
authors.forename: Liang
authors.initials: L
authors.lastname: Zhi Xu
mesh_terms: D041721:3T3-L1 Cells; D000818:Animals; D002113:Calcification, Physiologic; D002454:Cell Differentiation; D049109:Cell Proliferation; D000090602:Collagen Type I, alpha 1 Chain; D005260:Female; D005353:Fibronectins / Q000502:physiology*; D020935:MAP Kinase Signaling System; D059630:Mesenchymal Stem Cells / Q000502:physiology; D051379:Mice; D010006:Osteoblasts / Q000502:physiology; D017207:Rats, Sprague-Dawley
chemical_list: C000716129:Col1a1 protein, rat; D000090602:Collagen Type I, alpha 1 Chain; C571428:FNDC5 protein, mouse; D005353:Fibronectins