title: Autophagy plays a protective role in cell death of osteoblasts exposure to lead chloride.
abstract: Lead (Pb) is a toxic heavy metal widespreadly used in industrial field. Prior studies showed that Pb exposure had detrimental effects on osteoblasts. The mechanisms underlying Pb-induced damage are complex. Autophagy can protect cells from various cytotoxic stimuli. In the present study, the aim of our research was to investigate whether Pb could activate autophagy to play a protective role against osteoblasts apoptosis. Our results indicated that PbCl2 induced autophagy and autophagic flux in MC3T3-E1 murine osteoblastic cell by RT-PCR, western blot, as well as fluorescence microscopy analysis of GFP-LC3, AO and MDC staining. Pb increased the apoptosis of osteoblasts, evidenced by western blot and Hoechst 33258 staining assessment. In addition, inhibiting autophagy by 3-MA further increased the osteoblasts apoptosis after Pb exposure, showed by flow cytometry and Hoechst 33258 staining. Furthermore, phosphorylation of mTOR and p70S6K was inhibited by Pb exposure, indicating that Pb might induce autophagy in osteoblasts via inhibiting mTOR pathway. Altogether, these evidence suggested that Pb exporsure promoted autophagy flux in osteoblasts. The activation of autophagy by Pb played a protective role in osteoblasts apoptosis, which might be mediated through the mTOR pathway.
authors.affiliation: Department of Pharmacology, Guangdong Medical University, Zhanjiang, Guangdong 524023, China. Electronic address: lvxh96@163.com.
authors.forename: Xiao-hua
authors.initials: XH
authors.lastname: Lv
authors.affiliation: The Third Department of Orthopedics, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, China. Electronic address: dahang@vip.126.com.
authors.forename: Da-hang
authors.initials: DH
authors.lastname: Zhao
authors.affiliation: Department of Child and Adolescent Healthcare, The Children's Hospital of Soochow University, Suzhou, Jiangsu 215025, China. Electronic address: szcai@suda.edu.cn.
authors.forename: Shi-zhong
authors.initials: SZ
authors.lastname: Cai
authors.affiliation: Department of Pharmacology, Guangdong Medical University, Zhanjiang, Guangdong 524023, China. Electronic address: luosy76@126.com.
authors.forename: Shi-ying
authors.initials: SY
authors.lastname: Luo
authors.affiliation: Department of Pharmacology, Guangdong Medical University, Zhanjiang, Guangdong 524023, China. Electronic address: youtt2013@163.com.
authors.forename: Tingting
authors.initials: T
authors.lastname: You
authors.affiliation: Department of Pharmacology, Guangdong Medical University, Zhanjiang, Guangdong 524023, China. Electronic address: gdmcxu@126.com.
authors.forename: Bi-lian
authors.initials: BL
authors.lastname: Xu
authors.affiliation: Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong 518036, China; Department of Orthopaedics, Peking University Shenzhen Hospital, Shenzhen, Guangdong 518036, China. Electronic address: Xiao.han79@163.com.
authors.forename: Ke
authors.initials: K
authors.lastname: Chen
mesh_terms: D000818:Animals; D001343:Autophagy; D016923:Cell Death / Q000187:drug effects*; D007854:Lead / Q000633:toxicity*; D051379:Mice; D041681:NIH 3T3 Cells; D010006:Osteoblasts / Q000187:drug effects*
chemical_list: D007854:Lead; C029891:lead chloride
keywords: Apoptosis; Autophagic flux; Autophagy; Lead chloride (PbCl(2)); Osteoblasts; mTOR