title: Melatonin enhances chondrogenic differentiation of human mesenchymal stem cells.
abstract: Intramembranous ossification and endochondral ossification are two ways through which bone formation and fracture healing occur. Accumulating amounts of evidence suggests that melatonin affects osteoblast differentiation, but little is known about the effects of melatonin on the process of chondrogenic differentiation. In this study, the effects of melatonin on human mesenchymal stem cells (MSCs) undergoing chondrogenic differentiation were investigated. Cells were induced along chondrogenic differentiation via high-density micromass culture in chondrogenic medium containing vehicle or 50 nm melatonin. Histological study and quantitative analysis of glycosaminoglycan (GAG) showed induced cartilage tissues to be larger and richer in GAG, collagen type II and collagen type X in the melatonin group than in the untreated controls. Real-time RT-PCR analysis demonstrated that melatonin treatment significantly up-regulated the expression of the genes involved in chondrogenic differentiation, including aggrecan (ACAN), collagen type II (COL2A1), collagen type X (COL10A1), SRY (sex-determining region Y)-box 9 (SOX9), runt-related transcription factor 2 (RUNX2) and the potent inducer of chondrogenic differentiation, bone morphogenetic protein 2 (BMP2). And the expression of melatonin membrane receptors (MT) MT1 and MT2 were detected in the chondrogenic-induced-MSCs by immunofluorescence staining. Luzindole, a melatonin receptor antagonist, was found to partially block the ability of melatonin to increase the size and GAG synthesis of the induced cartilage tissues, as well as to completely reverse the effect of melatonin on the gene expression of ACAN, COL2A1, COL10A1, SOX9 and BMP2 after 7 days of differentiation. These findings demonstrate that melatonin enhances chondrogenic differentiation of human MSCs at least partially through melatonin receptors.
authors.affiliation: Department of Spine Surgery, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, China.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Gao
authors.forename: Mianlong
authors.initials: M
authors.lastname: Lin
authors.forename: Anjing
authors.initials: A
authors.lastname: Liang
authors.forename: Liangming
authors.initials: L
authors.lastname: Zhang
authors.forename: Changhua
authors.initials: C
authors.lastname: Chen
authors.forename: Guoyan
authors.initials: G
authors.lastname: Liang
authors.forename: Caixia
authors.initials: C
authors.lastname: Xu
authors.forename: Yan
authors.initials: Y
authors.lastname: Peng
authors.forename: Chong
authors.initials: C
authors.lastname: Chen
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Huang
authors.forename: Peiqiang
authors.initials: P
authors.lastname: Su
mesh_terms: D000704:Analysis of Variance; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D008550:Melatonin / Q000494:pharmacology*; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D044094:Receptors, Melatonin / Q000032:analysis / Q000737:chemistry / Q000378:metabolism
chemical_list: D044094:Receptors, Melatonin; D008550:Melatonin
keywords: bone morphogenetic protein 2; chondrogenic differentiation; human mesenchymal stem cells; melatonin; melatonin receptors