Tubuloside A alleviates sepsis-associated kidney injury by modulating the mTOR-NF-κB pathway.

Abstract

Sepsis-associated kidney injury (S-AKI) is a severe complication of sepsis, yet effective targeted therapies remain limited. We investigated the renoprotective effects of Tubuloside A (TA) and its mechanisms. S-AKI was induced in mice by cecal ligation and puncture, whereas an in vitro model was established using HK-2 cells exposed to lipopolysaccharide. Network pharmacology and molecular docking were used to explore potentially relevant targets and signaling pathways, and the involvement of autophagy-related processes was further examined using 3-methyladenine (3-MA). TA attenuated renal histopathological injury, reduced serum blood urea nitrogen and creatinine levels, and decreased the expression of the kidney injury markers KIM-1 and NGAL. TA also suppressed IL-1β, IL-6, and TNF-α expression while increasing IL-10 expression. TA also reduced ROS and MDA levels and increased CAT, GSH, and T-AOC activities, indicating antioxidant capacity. TA reduced Bax, cleaved caspase-3, and cleaved caspase-9 expression, increased Bcl-2 expression, and decreased the proportion of Annexin V-FITC/PI-positive cells. TA decreased the p-mTOR/mTOR ratio and p62 expression while increasing the LC3B-II/LC3B-I ratio, indicating modulation of mTOR-associated autophagy-related markers. TA also inhibited NF-κB activation, as evidenced by reduced p-p65 and p-IκBα levels, restored IκBα expression, and decreased nuclear p-p65 accumulation. CETSA further showed that TA altered the thermal stability profile of p65, providing experimental support for potential cellular target engagement of p65 by TA. Notably, 3-MA partially reversed these effects. Collectively, TA protects against S-AKI by alleviating inflammation, oxidative stress, and apoptosis, possibly through modulation of mTOR-associated autophagy-related processes and NF-κB signaling.