Klotho improves diabetic cardiomyopathy by suppressing the NLRP3 inflammasome pathway

NLRP3 inflammasome activation is essential for the development and prognosis of diabetic cardiomyopathy (DCM). The anti-aging protein Klotho is suggested to modulate tissue inflammatory responses. The aim of the present study was to examine the protective effects of Klotho on DCM. A streptozotocin-induced diabetes mouse model was established to assess the effects of Klotho in vivo, which was administered for 12 weeks. The characteristics of type 1 DCM were evaluated by general status, echocardiography, and histopathology. The expression of associated factors was determined by RT-qPCR and western blotting. Parallel experiments to determine the molecular mechanism through which Klotho prevents DCM were performed using H9C2 cells exposed to high glucose (35 mM). Diabetes-induced increases in serum creatine kinase-muscle/brain and lactate dehydrogenase levels, cardiac fibrosis, cardiomyocyte apoptosis, and cardiac dysfunction were ameliorated by Klotho. Additionally, Klotho suppressed TXNIP expression, NLRP3 inflammasome activation, and expression of the inflammatory cytokines tumor necrosis factor ɑ, interleukin-1β, and interleukin-18 in vivo. In high glucose-cultured cardiomyocytes, Klotho and N-acetylcysteine significantly downregulated intracellular reactive oxygen species generation and TXNIP/NLRP3 inflammasome activation. Pretreatment of H9C2 cells with NLRP3 siRNA or Klotho prevented high glucose-induced inflammation and apoptosis in H9C2 cells. Our results demonstrate that the protective effect of Klotho on diabetes-induced cardiac injury is associated with inhibition of the NLRP3 inflammasome pathway, suggesting its therapeutic potential for DCM.