Effect Of Lithium Chloride On Bone Loss And JAK/STAT3 Signaling Pathway In OVX Mice

Objectives This experiment is divided into two parts,in vivo: to explore the effect of lithium chloride intervention on bone loss and JAK/STAT3 signaling pathway in bilateral ovariectomized mice,and in vitro: the effect of lithium chloride intervention on osteoblast differentiation.Methods In vivo experimental part: 24 female 8-week-old C57BL6/J mice w ere randomly divided into: 1)sham operation group(Sham),2)ovariectomized op eration group(OVX)and 3)ovariectomized operation+Lithium chloride interventio n(OVX+Li Cl)group.The OVX group and the OVX+Li Cl group were treated with bilateral ovariectomy to establish a mouse osteoporosis model,and the OVX+Li C l group was given intragastric lithium chloride(100 mg/kg/d)1 week after the op eration.All mice were sacrificed after 8 weeks.The left and right femurs and rig ht tibias of the animals were collected and tested,including Micro-CT,immunohis tochemistry,and bone biomechanics.In vitro experiment part: The 3-day-old C57 B L/6 mice were sacrificed,and the calvarial bone was isolated to culture primary o steoblasts.Osteoblasts were randomly divided into 2 groups,blank group(Control) and Li Cl group(Li Cl),Li Cl group received Li Cl(5 mmol/L),after 7 days of trea tment,the cells were collected and tested,including alkaline phosphatase staining,cell activity detection and real-time quantitative PCR.Results 1 Micro-CT analysis results showed that the bone microstructure in the Sham group was generally normal.However,the microstructure in the OVX group changed abnormally,mainly including decreased bone mass,thinning of trabecular thickness,and decreased number of trabecular bone,the degree of separation of trabecular bone was increased,and the intervention of Li Cl significantly improved bone loss.2 Biomechanics results showed that the maximum load and maximum stress of the OVX group were significantly lower than those of the Sham group(P<0.05),and the maximum load and maximum stress of the OVX+Li Cl group were significantly higher than those of the OVX group(P<0.05).3 Immunohistochemical staining showed that the expression of JAK2 in the OVX+Li Cl group was significantly higher than that in the OVX group(P<0.05);the expression of P-STAT3 in the OVX group was significantly lower than that in the Sham group(P<0.05 vs.Sham),while the expression of OVX+Li Cl group was significantly increased(P<0.05 vs.OVX);the expression of STAT3 in the OVX+Li Cl group was significantly higher than that in the OVX group(P<0.05).4 The results of CCK8 assay showed that the proliferation activity of osteoblasts in the Li Cl group was significantly higher than that in the control group(P<0.05).5 The alkaline phosphatase activity and the number of calcium nodules in the Li Cl group were significantly higher than those in the control group(P<0.05).6 The expressions of STAT3 m RNA and OCN m RNA in Li Cl group were significantly higher than those in control group(P<0.05).Conclusions 1 Ovariectomy resulted in a significant decrease in bone mass and impaired bone microstructure in mice,indicating that the postmenopausal osteoporosis model was successfully established 2 The intervention of Li Cl significantly improved bone mass and bone microstructure in ovariectomized mice 3 Lithium chloride positively regulated the JAK/STAT3 signaling pathway in osteoblasts.Figure17;Table15;Reference 118...