Autophagy relieves the function inhibition and apoptosis‑promoting effects on osteoblast induced by glucocorticoid.
Autophagy relieves the function inhibition and apoptosis‑promoting effects on osteoblast induced by glucocorticoid.
复制标题
DOI：
10.3892/ijmm.2017.3270
复制
发表时间：
2018-03
影响因子：
5.4
通讯作者：
Chen Z
中科院分区：
文献类型：
--
作者：
Han Y;Zhang L;Xing Y;Zhang L;Chen X;Tang P;Chen Z
自噬可能是成骨细胞（OB）抵御长期使用糖皮质激素（GC）负面影响的主要机制。 OB 与 GC 诱导的骨质疏松症 (GIO) 中发生的重塑密切相关。在骨细胞中，为了响应 GC 诱导的应激，多种途径被激活，包括细胞坏死、细胞凋亡和自噬。然而，过量 GC 治疗后自噬在 OB 中的作用尚未得到解决。本研究通过共聚焦显微镜观察绿色荧光蛋白-微管相关蛋白1轻链3β(LC3)点状结构，并对LC3II和Beclin 1进行蛋白质印迹检测MC3T3-E1成骨细胞系中的自噬。采用流式细胞术和Western blotting检测细胞凋亡及BAX凋亡调节因子(Bax)/凋亡调节因子Bcl-2(Bcl-2)的表达。通过逆转录定量聚合酶链反应测量与成骨细胞功能相关的基因、runt 相关转录因子 2、α-1 1 型胶原和骨钙素的表达。结果表明，在地塞米松 (Dex) 治疗期间，OB 中的自噬以剂量依赖性方式被诱导。自噬水平并没有随时间持续增加，而是在48小时达到峰值，然后逐渐下降。随后，使用流式细胞术证明Dex处理下自噬的抑制诱导OB细胞凋亡，并与Bax上调和Bcl-2蛋白表达下调相关。此外，数据表明，自噬的抑制也抑制了成骨细胞基因的表达。相比之下，在 Dex 处理下，自噬的刺激维持了基因表达水平。数据显示，自噬通过与 Bax/Bcl-2 相互作用，成为成骨细胞凋亡的重要调节因子，并在 GC 暴露后维持 MC3T3-E1 细胞的成骨功能。此外，这些结果表明，慢性GC治疗下OB自噬的抑制可能会增加GIO和脆性骨折的患病率。
Autophagy may be a major mechanism by which osteoblasts (OBs) protect against the negative effects of chronic glucocorticoid (GC) usage. OBs are closely associated with the remodeling that occurs in GC-induced osteoporosis (GIO). In osteocytes, in response to stress induced by GCs, several pathways are activated, including cell necrosis, apoptosis and autophagy. However, the role of autophagy in OBs following treatment with excess GCs has not been addressed. In the current study, confocal microscopy observation of green fluorescent protein-microtubule-associated protein 1 light chain 3β (LC3) punctuate, and western blotting for LC3II and Beclin 1 were performed for detection of autophagy in the MC3T3-E1 osteoblastic cell line. Flow cytometry and western blotting were used for the examination of apoptosis and expression of BAX apoptosis regulator (Bax)/apoptosis regulator Bcl-2 (Bcl-2). The expression of genes associated with osteoblastic function, runt-related transcription factor 2, α-1 type 1 collagen and osteocalcin, were measured by reverse transcription-quantitative polymerase chain reaction. The results indicated that autophagy was induced in OBs during dexamethasone (Dex) treatment in a dose-dependent manner. The level of autophagy did not continue to increase over time, but peaked at 48 h and then decreased gradually. Subsequently, flow cytometry was used to demonstrate that inhibition of autophagy induced apoptosis in OBs under Dex treatment, and was associated with the upregulation of Bax and the downregulation of Bcl-2 protein expression. Furthermore, the data suggested that the inhibition of autophagy also suppressed the expression of osteoblastic genes. By contrast, the stimulation of autophagy maintained the gene expression level under Dex treatment. The data revealed that autophagy is an important regulator of osteoblastic apoptosis through its interaction with Bax/Bcl-2, and maintains the osteoblastic function of MC3T3-E1 cells following GC exposure. In addition, these results indicated that the suppression of autophagy in OBs under chronic GC therapy may increase the prevalence of GIO and fragility fractures.
登录
查看更多内容
影响因子：
11.1
作者：
He C;Klionsky DJ
通讯作者：
Klionsky DJ
影响因子：
64.5
作者：
Chipuk JE;McStay GP;Bharti A;Kuwana T;Clarke CJ;Siskind LJ;Obeid LM;Green DR
通讯作者：
Green DR
影响因子：
13.3
作者：
Nollet, Marie;Santucci-Darmanin, Sabine;Pierrefite-Carle, Valerie
通讯作者：
Pierrefite-Carle, Valerie
影响因子：
6.2
作者：
Kanis, JA;Johansson, H;Mellstrom, D
通讯作者：
Mellstrom, D
影响因子：
4.1
作者：
Canalis, E;Bilezikian, JP;Giustina, A
通讯作者：
Giustina, A