title: Leptin promotes ossification through multiple ways of bone metabolism in osteoblast: a pilot study.
abstract: Leptin may be a potential option in preventing osteoporosis for menopausal women. The objective of this study is to explore the molecular mechanism of leptin on bone metabolism in osteoblast. Primary osteoblasts were isolated from parietal bone of adult female rats. mRNA level of OB-Rb in osteoblasts was inhibited by siRNA to block leptin signal transmission. The whole genome expression was tested by using gene chip to preliminarily explore the molecular mechanism of leptin in regulating osteoblast activity. The optimal concentration of siRNA was 25 nM, resulting in a maximal inhibition of OB-Rb mRNA. Ossification (p < 0.05) and bone mineralization (p = 0.0001) were downregulated by inhibiting leptin signal transmission, while bone resorption (p = 0.007), osteoblast differentiation (p = 0.026) and negative regulation of bone remodeling (p = 0.004) were upregulated. The expressions of some genes were regulated by OB-Rb siRNA. The expressions of alkaline phosphatase (p = 0.014) and osteocalcin (p = 0.002) were reduced, while that of vascular endothelial growth factor A (p = 0.0076) and IL-6 (p = 0.021) were increased. In a model of osteoblast, leptin positively promotes ossification through multiple ways including bone mineralization, remodeling, resorption and osteoblast differentiation, but which way plays the most critical role is not discussed in this study and needs to be clarified in future.
authors.affiliation: Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Tingting
authors.initials: T
authors.lastname: Li
authors.forename: Liangzhi
authors.initials: L
authors.lastname: Xu
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Li
authors.forename: Meng
authors.initials: M
authors.lastname: Cheng
authors.forename: Jing
authors.initials: J
authors.lastname: Zhuang
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.forename: Wenming
authors.initials: W
authors.lastname: Xu
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000187:drug effects* / Q000378:metabolism; D002113:Calcification, Physiologic / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D004353:Drug Evaluation, Preclinical; D005260:Female; D020738:Leptin / Q000494:pharmacology*; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D010012:Osteogenesis / Q000187:drug effects*; D010865:Pilot Projects; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D020738:Leptin