Hirudin Ameliorates Kidney Injury in DKD Mice by Decreasing SOD2 β‐Hydroxybutyrylation Mediated ROS Level and NLRP3 Inflammasome Formation

ABSTRACT Inflammation and oxidative stress play crucial roles in the pathogenesis of diabetic kidney disease (DKD). Hirudin, a small molecular polypeptide derived from the salivary glands of leeches, is widely utilized in anti‐coagulation and antithrombotic therapies. However, the effects and underlying molecular mechanisms of hirudin on DKD remain unclear. Db/db mice were employed to evaluate the effects of hirudin on DKD. Key parameters assessed included urinary albumin, oral glucose tolerance, glomerular diameter, and the expression levels of NLRP3, IL‐1β, IL‐18, caspase‐1, and reactive oxygen species (ROS). Additionally, proteomic analysis was performed to measure the β‐hydroxybutyrylation level of SOD 2 , and the effects of changes in SOD 2 β‐hydroxybutyrylation were evaluated by immunoprecipitation. In vivo experiments demonstrated that hirudin significantly improved urinary albumin levels, oral glucose tolerance, and glomerular diameter in diabetic mice. Furthermore, the β‐hydroxybutyrylation level of SOD 2 was reduced, leading to decreased production of ROS and suppression of NLRP3 inflammasome activation. In vitro experiments indicated that hirudin reduced the polarization of RAW264.7 cells, lowered their ROS levels, diminished NLRP3 inflammasome activation, and reduced the β‐hydroxybutyrylation modification level of SOD 2 . Hirudin can alleviate the progression of DKD by reducing the β‐hydroxybutyrylation level of SOD 2 , which in turn reduces ROS production and NLRP3 inflammasome activation, thereby suppressing inflammation. These findings provide new insights into the potential application of hirudin in the context of DKD.