Department of Orthopedics, Xiaoshan TCM Hospital, Xiaoshan, Hangzhou 311201, P.R. China.
Mol Med Rep. 2018 Jan;17(1):1591-1598. doi: 10.3892/mmr.2017.8053. Epub 2017 Nov 14.
Osteoporosis is an aging process of skeletal tissues with characteristics of reductions in bone mass and microarchitectural deterioration of bone tissue. The present study aimed to investigate the effects of glucocorticoid‑induced osteoporosis on osteoblasts and to examine the roles of β‑ecdysterone (β‑Ecd) involved. In the present study, an in vivo model of osteoporosis was established through the subcutaneous implantation of prednisolone (PRED) into Sprague‑Dawley rats, with or without a subcutaneous injection of β‑Ecd (5 or 10 mg/kg body weight). Expression of Beclin‑1 and microtubule‑associated protein 1A/1B‑light chain 3I/II and apoptosis in lumbar vertebrae tissues was measured by immunofluorescence and TUNEL assays, respectively. Serum concentration of calcium and phosphorus, and the activity of tartrate‑resistant acid phosphatase (TRAP) and alkaline phosphatase (ALP) were measured by biochemical assay. Reverse transcription‑quantitative polymerase chain reaction and western blotting was used for detect the expression of related genes and proteins. PRED treatment inhibited bone formation by decreasing bone mineral density, and suppressing the expression of Runt‑related transcription factor 2 and bone morphogenetic protein 2, while enhancing the activity of alkaline phosphatase, upregulating the expression of receptor activator of nuclear factor-κB ligand, and increasing the serum content of calcium, phosphorus and tartrate‑resistant acid phosphatase in rats. Additionally, PRED was revealed to inhibit autophagy through the downregulation of Beclin‑1, autophagy protein 5 and microtubule‑associated protein 1A/1B‑light chain 3I/II expression, whereas it induced the apoptosis, through the activation of caspase‑3 and the suppression of apoptosis regulator BCL2 expression. Notably, the PRED‑induced alterations in bone formation, autophagy and apoptosis were revealed to be attenuated by β‑Ecd administration. In conclusion, the findings of the present study suggested that β‑Ecd may be a promising candidate for the development of therapeutic strategies for the treatment of osteoporosis, through the induction of autophagy and the inhibition of apoptosis in vivo.
骨质疏松症是一种骨骼组织的老化过程，其特征是骨量减少和骨组织的微观结构恶化。本研究旨在探讨糖皮质激素诱导的骨质疏松症对成骨细胞的影响，并研究β-蜕皮甾酮（β-Ecd）所涉及的作用。在本研究中，通过将泼尼松龙（PRED）皮下植入 Sprague-Dawley 大鼠，建立了骨质疏松症的体内模型，同时或不进行β-Ecd（5 或 10mg/kg 体重）皮下注射。通过免疫荧光和 TUNEL 检测分别测量腰椎组织中 Beclin-1 和微管相关蛋白 1A/1B-轻链 3I/II 和细胞凋亡的表达。通过生化测定测量血清钙和磷浓度，以及抗酒石酸酸性磷酸酶（TRAP）和碱性磷酸酶（ALP）的活性。通过逆转录-定量聚合酶链反应和蛋白质印迹法检测相关基因和蛋白的表达。PRED 处理通过降低骨密度、抑制 Runt 相关转录因子 2 和骨形态发生蛋白 2 的表达，同时增强碱性磷酸酶的活性、上调核因子-κB 受体激活剂配体的表达、增加血清中钙、磷和抗酒石酸酸性磷酸酶的含量来抑制骨形成。此外，PRED 通过下调 Beclin-1、自噬蛋白 5 和微管相关蛋白 1A/1B-轻链 3I/II 的表达来抑制自噬，同时通过激活 caspase-3 和抑制凋亡调节因子 BCL2 的表达来诱导细胞凋亡。值得注意的是，β-Ecd 的给药减弱了 PRED 诱导的骨形成、自噬和细胞凋亡的改变。总之，本研究的结果表明，β-Ecd 可能是一种有前途的候选药物，可通过体内诱导自噬和抑制细胞凋亡来治疗骨质疏松症。
