地塞米松通过 Chk2/p53 信号通路促进成骨细胞凋亡。

Dexamethasone promotes osteoblast apoptosis through the Chk2/p53 signaling pathway.

机构信息

Department of Orthopaedics, Children's Hospital of Soochow University, Suzhou, China.

Suzhou Key Laboratory for Tumor Immunology of Digestive Tract, The First Affiliated Hospital of Soochow University, Suzhou, China.

出版信息

Adv Clin Exp Med. 2022 Dec;31(12):1365-1374. doi: 10.17219/acem/152150.

DOI:10.17219/acem/152150

PMID:36083253

Abstract

BACKGROUND

Glucocorticoids (GCs) are widely used to treat inflammatory or autoimmune diseases. However, several studies have reported that the use of GCs can lead to numerous complications, the most serious of which are osteoporosis and osteonecrosis of the femoral head (ONFH). Osteoblast apoptosis has been identified as an important event in the development of GC-induced osteoporosis and ONFH. However, the mechanisms underlying the regulation of these processes have not yet been explored.

OBJECTIVES

To observe the effect of dexamethasone (Dex) on the apoptosis of osteoblasts and explore its mechanism, as well as provide a new therapeutic idea for GC‑induced osteoporosis and ONFH.

MATERIAL AND METHODS

Cell proliferation and apoptosis of MC3T3-E1 cells after Dex treatment were determined using the CellTiter-Glo® Luminescent Cell Viability Assay kit and Annexin V-FITC/PI Double Staining Apoptosis Detection Kit, respectively. The expression of caspase-3/cleaved caspase-3 and poly(ADP-ribose) polymerase (PARP)/cleaved PARP in MC3T3-E1 cells after Dex treatment was determined with western blotting. The expression of p53 and checkpoint kinase 2 (Chk2) in MC3T3-E1 cells after Dex treatment was analyzed using western blotting and polymerase chain reaction (PCR). The effects of p53 knockdown and Chk2 knockdown on Dex-induced apoptosis of MC3T3-E1 cells were also characterized.

RESULTS

Dexamethasone remarkably inhibited cell growth and induced the apoptosis of MC3T3-E1 cells. We also observed that Dex induced osteoblast apoptosis by promoting p53 expression. The regulatory effect of Dex on p53 expression is mediated by the upregulation of Chk2, which interacted with p53 and inhibited p53 degradation. The knockdown of p53 alleviated Dex-induced MC3T3-E1 cell apoptosis by decreasing the expression of cleaved caspase-3 and cleaved PARP.

CONCLUSIONS

We demonstrated that Dex increased Chk2 protein expression, which stabilized the protein expression of p53, and in turn promoted osteoblast apoptosis.

摘要

背景

糖皮质激素（GCs）广泛用于治疗炎症或自身免疫性疾病。然而，多项研究报道，GCs 的使用会导致许多并发症，其中最严重的是骨质疏松症和股骨头坏死（ONFH）。成骨细胞凋亡已被确定为 GC 诱导的骨质疏松症和 ONFH 发展中的一个重要事件。然而，这些过程的调节机制尚未得到探索。

目的

观察地塞米松（Dex）对成骨细胞凋亡的影响，并探讨其机制，为 GC 诱导的骨质疏松症和 ONFH 提供新的治疗思路。

材料与方法

用 CellTiter-Glo® 发光细胞活力检测试剂盒和 Annexin V-FITC/PI 双染凋亡检测试剂盒分别测定 Dex 处理后 MC3T3-E1 细胞的增殖和凋亡。用 Western blot 测定 Dex 处理后 MC3T3-E1 细胞中 caspase-3/cleaved caspase-3 和聚（ADP-核糖）聚合酶（PARP）/cleaved PARP 的表达。用 Western blot 和聚合酶链反应（PCR）分析 Dex 处理后 MC3T3-E1 细胞中 p53 和检查点激酶 2（Chk2）的表达。还研究了 p53 敲低和 Chk2 敲低对 Dex 诱导的 MC3T3-E1 细胞凋亡的影响。

结果

地塞米松显著抑制细胞生长并诱导 MC3T3-E1 细胞凋亡。我们还观察到，地塞米松通过促进 p53 表达诱导成骨细胞凋亡。Dex 对 p53 表达的调节作用是通过上调 Chk2 介导的，Chk2 与 p53 相互作用并抑制 p53 降解。p53 敲低通过降低 cleaved caspase-3 和 cleaved PARP 的表达减轻 Dex 诱导的 MC3T3-E1 细胞凋亡。