PLAU and diabetic kidney disease: As a multitarget serine protease inhibitor, plasminogen activator inhibitor-1(PAI-1) plays a pro-fibrotic function in both UUO and diabetic nephropathy models, primarily mediated by inhibiting tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA) thereby promoting ECM deposition and suppressing fibrinlysis (Gu et al., 2016; Yao et al., 2019).