Zhigang Nie1, Sen Chen1, Hao Peng2. 1. Department of Orthopedics, Renmin Hospital of Wuhan University, Wuhan, Hubei, China. 2. Department of Orthopedics, Renmin Hospital of Wuhan University, Wuhan, Hubei, China. Electronic address: penghaowhu5868@163.com.
Abstract
OBJECTIVE: One of the important causes of glucocorticoids (GCs)-induced osteonecrosis of the femoral head (ONFH) is osteoblast apoptosis. Glycogen synthase kinase 3β (GSK3β) has been reported to be related to dexamethasone (Dex)-induced osteoblast apoptosis. This study aimed to determine whether GSK3β plays role in GC-induced ONFH and investigate the underlying mechanism. METHODS: 18 male Sprague-Dawley rats were divided into 3 groups. Rats from ONFH group underwent lipopolysaccharide and methylprednisolone injection. Lithium chloride (LiCl, a GSK3β inhibitor) group were fed with LiCl solution. The control group were untreated. Osteonecrosis, apoptosis and bone loss were evaluated by HE staining, TUNEL staining and micro-CT respectively. Protein expressions were examined by western blotting. In addition, primary osteoblast cells were transfected by GSK3β-siRNA and related signaling pathway and proteins were examined. RESULTS: ONFH group showed a relative high percentage of empty lacunae and apoptotic cells, whilst LiCl treatment markedly decreased the percentage. LiCl treatment decreased GC-induced bone loss. Immunoblot analysis for GSK3β showed decreased level of Ser9-phosphorylated GSK3β in ONFH group compared with control group. Knockdown of GSK3β by siRNA in primary osteoblast cells attenuated DEX-induced apoptosis and loss of mitochondrial transmembrane potential (Δψm). GSK3β knockdown also reversed the release of cytochrome C (Cyt C) from mitochondria to the cytosol. GSK3β decreased apoptosis-related protein expression both in vitro and in vivo. CONCLUSION: Our findings suggest that GC induces ONFH in rats through GSK3β-mediated osteoblast apoptosis, with involvement of mitochondrial apoptotic pathway.
OBJECTIVE: One of the important causes of glucocorticoids (GCs)-induced osteonecrosis of the femoral head (ONFH) is osteoblast apoptosis. Glycogen synthase kinase 3β (GSK3β) has been reported to be related to dexamethasone (Dex)-induced osteoblast apoptosis. This study aimed to determine whether GSK3β plays role in GC-induced ONFH and investigate the underlying mechanism. METHODS: 18 male Sprague-Dawley rats were divided into 3 groups. Rats from ONFH group underwent lipopolysaccharide and methylprednisolone injection. Lithium chloride (LiCl, a GSK3β inhibitor) group were fed with LiCl solution. The control group were untreated. Osteonecrosis, apoptosis and bone loss were evaluated by HE staining, TUNEL staining and micro-CT respectively. Protein expressions were examined by western blotting. In addition, primary osteoblast cells were transfected by GSK3β-siRNA and related signaling pathway and proteins were examined. RESULTS: ONFH group showed a relative high percentage of empty lacunae and apoptotic cells, whilst LiCl treatment markedly decreased the percentage. LiCl treatment decreased GC-induced bone loss. Immunoblot analysis for GSK3β showed decreased level of Ser9-phosphorylated GSK3β in ONFH group compared with control group. Knockdown of GSK3β by siRNA in primary osteoblast cells attenuated DEX-induced apoptosis and loss of mitochondrial transmembrane potential (Δψm). GSK3β knockdown also reversed the release of cytochrome C (Cyt C) from mitochondria to the cytosol. GSK3β decreased apoptosis-related protein expression both in vitro and in vivo. CONCLUSION: Our findings suggest that GC induces ONFH in rats through GSK3β-mediated osteoblast apoptosis, with involvement of mitochondrial apoptotic pathway.
Authors: Rossella Cannarella; Federica Barbagallo; Rosita A Condorelli; Antonio Aversa; Sandro La Vignera; Aldo E Calogero Journal: J Clin Med Date: 2019-10-01 Impact factor: 4.241
Authors: Innocent U Okagu; Timothy P C Ezeorba; Rita N Aguchem; Ikenna C Ohanenye; Emmanuel C Aham; Sunday N Okafor; Carlotta Bollati; Carmen Lammi Journal: Int J Mol Sci Date: 2022-07-30 Impact factor: 6.208