Shelke Vishwadeep, Dagar Neha, Gaikwad Anil Bhanudas
Department of Pharmacy, Birla Institute of Technology and Science, Pilani Campus, Pilani, Rajasthan, 333031, India.
Appl Biochem Biotechnol. 2025 Jul 3. doi: 10.1007/s12010-025-05315-z.
The diabetic milieu increases the chances of acute kidney injury (AKI) progression. During AKI, activation of the inflammatory response via Toll-like receptor 4 (TLR4) and endoplasmic reticulum (ER) stress progress in kidney dysfunction. Moreover, emerging evidence suggests a functional interplay between TLR4 signaling and ER stress in kidney disease. However, the effect of simultaneous inhibition of these mechanisms has not yet been studied in AKI under diabetic settings. In this study, we investigated the renoprotective effect of Phloretin-TLR4 inhibitor and Tauro ursodeoxycholic acid (TUDCA)-ERS inhibitor in AKI under diabetic condition. Using a bilateral ischemia-reperfusion injury (BIRI) model in streptozotocin-induced diabetic rats and a high glucose cultured sodium azide-induced injury model in NRK52E cells, we evaluated the effects of both agents administered alone and in combination. In rats, phloretin at 50 mg/kg/p.o. and TUDCA at 400 mg/kg/p.o. alone and in combination were administered for 5 days before surgery, while in NRK52E cells, both drugs were given 24 h before hypoxia. Pretreatment with phloretin and TUDCA significantly attenuated renal dysfunction, preserved tissue architecture, and reduced markers of inflammation and apoptosis (p < 0.05). Mechanistic analysis revealed that phloretin suppressed the TLR4/MyD88/NF-κB signaling pathway, while TUDCA inhibited ER stress via the BiP/PERK/CHOP axis. Notably, combination therapy exhibited a synergistic effect (p < 0.05), offering superior renoprotection compared to monotherapy. Our findings suggest that targeting both TLR4-induced inflammation and ER stress simultaneously offers a promising therapeutic strategy for mitigating AKI in diabetic settings and may pave the way for novel combination treatments in diabetic kidney disease.
糖尿病环境会增加急性肾损伤（AKI）进展的几率。在AKI期间，通过Toll样受体4（TLR4）激活炎症反应以及内质网（ER）应激会导致肾功能障碍。此外，新出现的证据表明TLR4信号传导与肾脏疾病中的ER应激之间存在功能相互作用。然而，在糖尿病环境下的AKI中，同时抑制这些机制的效果尚未得到研究。在本研究中，我们研究了根皮素-TLR4抑制剂和牛磺熊去氧胆酸（TUDCA）-ERS抑制剂在糖尿病条件下对AKI的肾脏保护作用。使用链脲佐菌素诱导的糖尿病大鼠双侧缺血再灌注损伤（BIRI）模型以及NRK52E细胞中高糖培养叠氮化钠诱导的损伤模型，我们评估了单独使用和联合使用这两种药物的效果。在大鼠中，术前5天单独或联合给予50mg/kg口服根皮素和400mg/kg口服TUDCA，而在NRK52E细胞中，两种药物在缺氧前24小时给予。根皮素和TUDCA预处理显著减轻了肾功能障碍，保留了组织结构，并减少了炎症和凋亡标志物（p<0.05）。机制分析表明，根皮素抑制TLR4/MyD88/NF-κB信号通路，而TUDCA通过BiP/PERK/CHOP轴抑制ER应激。值得注意的是，联合治疗表现出协同作用（p<0.05），与单一疗法相比提供了更好的肾脏保护作用。我们的研究结果表明，同时针对TLR4诱导的炎症和ER应激提供了一种有前景的治疗策略，用于减轻糖尿病环境下的AKI，并可能为糖尿病肾病的新型联合治疗铺平道路。
