title: Bovine parathyroid hormone enhances osteoclast bone resorption by modulating V-ATPase through PTH1R.
abstract: The vacuolar-type H+ adenosine triphosphatase (V-ATPase) plays an important role in cellular acidification and bone resorption by osteoclasts. However, the direct effect of bovine parathyroid hormone (bPTH) on V-ATPase has not yet been elucidated. The aim of the present study was to assess the effects of bPTH on V-ATPase and osteoclasts. Osteoclasts from bone marrow (BM)-derived monocytes of C57BL/6 mice were cultured with or without bPTH. The mRNA and protein expression levels of the V-ATPase a3-subunit and d2-subunit (by RT-qPCR and western blot analysis), V-ATPase activity (using the V type ATPase Activity Assay kit) and the bone resorption function of osteoclasts (by bone resorption assay) were examined following treatment with various concentrations of bPTH (0.1, 1.0, 10 and 100 ng/ml) alone or with bPTH and its inhibitor, bafilomycin A1. Furthermore, the expression of parathyroid hormone (PTH) receptors in osteoclasts was also detected. The results revealed that the mRNA and protein expression levels of V-ATPase a3-subunit and d2-subunit increased in a dose‑dependent manner, paralleling the level of bPTH present. In addition, an increase in the concentration of bPTH was accompanied by the increased resorption capability of osteoclasts, whereas bone resorption was inhibited in the presence of bafilomycin A1. In addition, we confirmed the existence of parathyroid hormone 1 receptor (PTH1R) in osteoclasts using three different methods (RT-qPCR, western blot analysis and immunofluorescence staining). We found that bPTH enhanced the bone resorption capability of osteoclasts by modulating the expression of V-ATPase subunits, intracellular acidification and V-ATPase activity. Thus, we propose that PTH has a direct effect on osteoblasts and osteoclasts, and that this effect is mediated through PTH1R, thus contributing to bone remodeling.
authors.affiliation: Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Shuangxin
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Nephrology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong 519000, P.R. China.
authors.forename: Weiping
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Sijia
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Jianchao
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Nephrology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong 519000, P.R. China.
authors.forename: Huitao
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Nephrology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong 519000, P.R. China.
authors.forename: Zhonghe
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Xinling
authors.initials: X
authors.lastname: Liang
authors.affiliation: Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Shi
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000378:metabolism; D016723:Bone Remodeling / Q000235:genetics*; D001862:Bone Resorption / Q000235:genetics* / Q000473:pathology; D002417:Cattle; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D018942:Macrolides / Q000008:administration & dosage; D051379:Mice; D010010:Osteoclasts / Q000378:metabolism / Q000473:pathology; D010281:Parathyroid Hormone / Q000008:administration & dosage / Q000378:metabolism; D044168:Receptor, Parathyroid Hormone, Type 1 / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D025262:Vacuolar Proton-Translocating ATPases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D018942:Macrolides; D010281:Parathyroid Hormone; D044168:Receptor, Parathyroid Hormone, Type 1; C040929:bafilomycin A1; D025262:Vacuolar Proton-Translocating ATPases