糖尿病性骨质疏松症是糖尿病（DM）的并发症。 Denosumab (DMB) 是一种有效的抗骨质疏松药物，通过抑制 NF-κB 配体受体激活因子 (RANKL) 发挥作用。先前的研究发现，骨保护素（OPG）通过RNAK/RANKL通路调节β细胞稳态。本研究旨在探讨RANKL/RANK对DM病理过程的影响及其机制。我们使用D-葡萄糖诱导的RINm5F细胞构建体外2型糖尿病模型（T2DM）。采用高脂饮食联合腹腔注射链脲佐菌素（STZ）建立SD大鼠T2DM模型。通过 TdT 介导的 dUTP 缺口末端标记 (TUNEL) 分析测定 β 细胞的凋亡。采用 qRT-PCR 和蛋白质印迹法检测 TRAF3（肿瘤坏死因子受体相关因子）/NIK（NF-κB 诱导激酶）通路的 mRNA 和蛋白表达。此外，通过ELISA和免疫组织化学法检测胰岛素表达。 H 分析胰岛形态

Diabetic osteoporosis is a complication of diabetes mellitus (DM). Denosumab (DMB) is an effective anti-osteoporotic drug functions by inhibiting NF-κB ligand receptor-activating factor (RANKL). Previous study found that osteoprotegerin (OPG) regulated βcell homeostasis through the RNAK/RANKL pathway. The present study aimed to investigate the effect of RANKL/RANK on the pathological process of DM and the underlying mechanism. We used D-glucose-induced RINm5F cells to construct in vitro type 2 diabetes models (T2DM). A high-fat diet combined with intraperitoneal injection of streptozotocin (STZ) was used to establish a T2DM model in SD rats. The apoptosis of β-cells was determined by TdT-mediated dUTP nick-end labeling (TUNEL) analysis. qRT-PCR and western blotting assays were used to explore the mRNA and protein expression of the TRAF3 (Tumor necrosis factor receptor-associated factor)/NIK (NF-κB-inducible kinase) pathway. Furthermore, insulin expression was detected by ELISA and immunohistochemistry assay. The islet morphology was analyzed by H&E. In vivo experiments demonstrated that sRANKL-IN-3 down-regulated insulin secretion levels by significantly ameliorating pancreatic tissue damage and mitigating apoptosis of high glucose induced β-cells. Subsequently, sRANKL-IN-3, acting as an inhibitor of RANKL, mitigated functional decline in β-cells induced by high glucose, mainly manifested by the low expression of PDX-1 (pancreatic duodenal homeobox 1), BETA2 (beta-2 adrenoceptors), INS-1 (insulin 1), and INS-2 (insulin 2). Mechanistic studies revealed that deletion of TRAF3 combined with sRANKL-IN-3 administration reduced the activity of NIK, NF-κB2, and RelB in RINm5F cells. In addition, our study demonstrated that inhibition of either RANKL or TRAF3 had a protective effect on high glucose induced apoptosis. Moreover, the combined action of sRANKL-IN-3 and shTRAF3 had a more pronounced inhibitory effect on high glucose-induced apoptosis. In summary, RANKL/RANK deficiency may attenuate apoptosis of β-cells, a phenomenon associated with the TRAF3/NIK pathway. Therefore, RANKL/RANK could be regarded as a potential therapeutic strategy for DM.Copyright © 2024 Elsevier B.V. All rights reserved.