463-P: Linagliptin Ameliorated Heart Damage Associated with the Suppression of Necroptosis in Type 1 Diabetic Mice

Abstract

Background: In diabetic patients, the incident of heart failure is two to five times greater when compared to that of general population. The influence of DPP-4 inhibitor on the heart failure and cardiac damage in diabetes is not completely elucidated yet. Therefore, to understand the pathobiology of heart damage in diabetes and the influence of DPP-4 inhibitor is emerged as significant. Necroptosis, recently identified as programmed cell death, had shown to be involved in heart damage of ischemic heart disease model. Here we found that intervention with DPP-4 inhibitor linagliptin (LINA) ameliorated heart damage in diabetic mice associated with the suppression of necroptosis. Method: We utilized streptozotocin-induced diabetic CD-1 mice (STZ:200mg/kg). At 20 weeks after the onset of diabetes, diabetic mice were treated with LINA (STZ+LINA) for 4 weeks. Result: Blood pressure, blood glucose, body and heart weights were not different between STZ and STZ+LINA. Ultrasonic Echocardiography analysis revealed that LVDd and LVDs were significantly decreased in STZ and STZ+LINA compared with control. STZ-induced diabetic CD-1 mice exhibited perivascular fibrosis evaluated by picrosirius red staining and strong immunoreactivity for DPP-4 expression in cardiac interstitium; STZ+LINA exhibited suppression of DPP-4 and amelioration of heart fibrosis. Diabetic CD-1 mice exhibited deficiency in myocardial stripe structure and endothelial damage in electron microscopy; LINA normalized all. When necroptosis was evaluated by associated kinases, RIP3 and MLKL, diabetic CD-1 mice were exhibited a strong RIP3 and MLKL mRNA and protein expression levels in myocyte; LINA suppressed RIP3 and MLKL levels in myocyte. Conclusion: These results indicated that LINA restored cardiac structure associated with suppression of necroptosis in type 1 diabetic mice. Disclosure T. Hirai: None. Y. Takagaki: None. K. Kanasaki: Other Relationship; Self; Astellas Pharma Inc., Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company, Mitsubishi Tanabe Pharma Corporation, Ono Pharmaceutical Co., Ltd., Sanofi, Taisho Toyama Pharmaceutical. D. Koya: Research Support; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Mitsubishi Tanabe Pharma Corporation. Speaker's Bureau; Self; Astellas Pharma Inc., Astellas Pharma Inc., AstraZeneca, Merck & Co., Inc., Mitsubishi Tanabe Pharma Corporation, Taisho Pharmaceutical Co., Ltd. Funding Japan Society for the Promotion of Science