Ma Hong-Dong, Shi Lei, Li Hai-Tian, Wang Xin-Dong, Yang Mao-Wei
Department of Orthopedics, The Affiliated Hospital of Nantong University, Nantong 226001, Jiangsu Province, China.
Department of Orthopedics, The First Hospital of China Medical University, Shenyang 110001, Liaoning Province, China.
World J Diabetes. 2024 May 15;15(5):977-987. doi: 10.4239/wjd.v15.i5.977.
Recently, type 2 diabetic osteoporosis (T2DOP) has become a research hotspot for the complications of diabetes, but the specific mechanism of its occurrence and development remains unknown. Ferroptosis caused by iron overload is con-sidered an important cause of T2DOP. Polycytosine RNA-binding protein 1 (PCBP1), an iron ion chaperone, is considered a protector of ferroptosis.
To investigate the existence of ferroptosis and specific role of PCBP1 in the development of type 2 diabetes.
A cell counting kit-8 assay was used to detect changes in osteoblast viability under high glucose (HG) and/or ferroptosis inhibitors at different concentrations and times. Transmission electron microscopy was used to examine the morphological changes in the mitochondria of osteoblasts under HG, and western blotting was used to detect the expression levels of PCBP1, ferritin, and the ferroptosis-related protein glutathione peroxidase 4 (GPX4). A lentivirus silenced and overexpressed PCBP1. Western blotting was used to detect the expression levels of the osteoblast functional proteins osteoprotegerin (OPG) and osteocalcin (OCN), whereas flow cytometry was used to detect changes in reactive oxygen species (ROS) levels in each group.
Under HG, the viability of osteoblasts was considerably decreased, the number of mitochondria undergoing atrophy was considerably increased, PCBP1 and ferritin expression levels were increased, and GPX4 expression was decreased. Western blotting results demonstrated that infection with lentivirus overexpressing PCBP1, increased the expression levels of ferritin, GPX4, OPG, and OCN, compared with the HG group. Flow cytometry results showed a reduction in ROS, and an opposite result was obtained after silencing PCBP1.
PCBP1 may protect osteoblasts and reduce the harm caused by ferroptosis by promoting ferritin expression under a HG environment. Moreover, PCBP1 may be a potential therapeutic target for T2DOP.
近年来，2型糖尿病性骨质疏松症（T2DOP）已成为糖尿病并发症的研究热点，但其发生发展的具体机制尚不清楚。铁过载引起的铁死亡被认为是T2DOP的重要病因。多聚胞嘧啶RNA结合蛋白1（PCBP1）作为一种铁离子伴侣，被认为是铁死亡的保护因子。
探讨铁死亡的存在及PCBP1在2型糖尿病发生发展中的具体作用。
采用细胞计数试剂盒-8法检测不同浓度和时间的高糖（HG）和/或铁死亡抑制剂作用下成骨细胞活力的变化。采用透射电子显微镜观察HG作用下成骨细胞线粒体的形态变化，采用蛋白质免疫印迹法检测PCBP1、铁蛋白和铁死亡相关蛋白谷胱甘肽过氧化物酶4（GPX4）的表达水平。通过慢病毒使PCBP1沉默和过表达。采用蛋白质免疫印迹法检测成骨细胞功能蛋白骨保护素（OPG）和骨钙素（OCN）的表达水平，采用流式细胞术检测各组活性氧（ROS）水平的变化。
在HG条件下，成骨细胞活力显著降低，萎缩线粒体数量显著增加，PCBP1和铁蛋白表达水平升高，GPX4表达降低。蛋白质免疫印迹结果显示，与HG组相比，过表达PCBP1的慢病毒感染可增加铁蛋白、GPX4、OPG和OCN的表达水平。流式细胞术结果显示ROS减少，沉默PCBP1后结果相反。
PCBP1可能通过在HG环境下促进铁蛋白表达来保护成骨细胞，减少铁死亡造成的损害。此外，PCBP1可能是T2DOP的潜在治疗靶点。
