Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.
Department of Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.
Eur J Pharmacol. 2024 Sep 15;979:176849. doi: 10.1016/j.ejphar.2024.176849. Epub 2024 Jul 25.
Senile osteoporosis (SOP), characterized by significant bone loss, poses a substantial threat to elderly skeletal health, with oxidative stress playing a crucial role in its pathogenesis. Although Tripartite Motif 16 (TRIM16) has been identified as a promoter of antioxidant response and osteogenic differentiation, its regulatory role in SOP remains incompletely understood. This study aims to elucidate the underlying mechanism of TRIM16 in mitigating D-galactose (D-gal)-induced senescent osteoblasts. Initially, we observed diminished bone mineral density (BMD) and impaired bone microstructure in naturally aging (24 months) and D-gal-induced (18 months) aged mice through Dual-energy X-ray absorptiometry (DEXA), micro-CT, hematoxylin and eosin staining, and Masson staining. Immunohistochemistry analysis revealed downregulation of TRIM16 and osteogenic differentiation markers (Collagen-1, Runx-2, osteopontin) in femur samples of aged mice. Furthermore, in D-gal-induced senescent MC3T3-E1 osteoblasts, we observed the suppression of osteogenic differentiation and maturity, along with cytoskeleton impairment via Alkaline phosphatase (ALP), Alizarin Red S, and Rhodamine-phalloidin staining. The protein expression of TRIM16, osteogenic differentiation markers, and antioxidant indicators (Nrf-2, HO-1, SOD1) decreased, while the production of reactive oxygen species (ROS) significantly increased. Knockdown and overexpression of TRIM16 using lentivirus in osteoblasts revealed that the downregulation of TRIM16 inhibited osteogenic differentiation and induced oxidative stress. Notably, TRIM16 overexpression partially attenuated D-gal-induced inhibition of osteogenic differentiation and increased oxidative stress. These findings suggest TRIM16 may mitigate impaired osteogenic differentiation and antioxidant response in D-gal-induced senescent osteoblasts, suggesting its potential as a therapeutic target for SOP.
老年性骨质疏松症（SOP）以显著的骨丢失为特征，对老年骨骼健康构成重大威胁，氧化应激在其发病机制中起着关键作用。虽然三结构域蛋白 16（TRIM16）已被确定为抗氧化反应和成骨分化的促进剂，但它在 SOP 中的调节作用仍不完全清楚。本研究旨在阐明 TRIM16 在减轻 D-半乳糖（D-gal）诱导的衰老成骨细胞中的作用机制。首先，我们通过双能 X 射线吸收法（DEXA）、微计算机断层扫描、苏木精和伊红染色以及 Masson 染色观察到自然衰老（24 个月）和 D-gal 诱导（18 个月）衰老小鼠的骨矿物质密度（BMD）降低和骨微结构受损。免疫组织化学分析显示衰老小鼠股骨样本中 TRIM16 和成骨分化标志物（Collagen-1、Runx-2、骨桥蛋白）表达下调。此外，在 D-gal 诱导的衰老 MC3T3-E1 成骨细胞中，我们观察到成骨分化和成熟受到抑制，细胞骨架受损，通过碱性磷酸酶（ALP）、茜素红 S 和罗丹明鬼笔环肽染色。TRIM16、成骨分化标志物和抗氧化指标（Nrf-2、HO-1、SOD1）的蛋白表达降低，而活性氧（ROS）的产生显著增加。使用慢病毒在成骨细胞中敲低和过表达 TRIM16，结果显示 TRIM16 下调抑制成骨分化并诱导氧化应激。值得注意的是，TRIM16 过表达部分减轻了 D-gal 诱导的成骨分化抑制和氧化应激增加。这些发现表明，TRIM16 可能减轻 D-gal 诱导的衰老成骨细胞中成骨分化受损和抗氧化反应减弱，提示其可能成为 SOP 的治疗靶点。
