PMID- 33754057 OWN - NLM STAT- MEDLINE DCOM- 20210729 LR - 20210729 IS - 1838-7640 (Electronic) IS - 1838-7640 (Linking) VI - 11 IP - 9 DP - 2021 TI - A novel role of kallikrein-related peptidase 8 in the pathogenesis of diabetic cardiac fibrosis. PG - 4207-4231 LID - 10.7150/thno.48530 [doi] AB - Rationale: Among all the diabetic complications, diabetic cardiomyopathy, which is characterized by myocyte loss and myocardial fibrosis, is the leading cause of mortality and morbidity in diabetic patients. Tissue kallikrein-related peptidases (KLKs) are secreted serine proteases, that have distinct and overlapping roles in the pathogenesis of cardiovascular diseases. However, whether KLKs are involved in the development of diabetic cardiomyopathy remains unknown.The present study aimed to determine the role of a specific KLK in the initiation of endothelial-to-mesenchymal transition (EndMT) during the pathogenesis of diabetic cardiomyopathy. Methods and Results-By screening gene expression profiles of KLKs, it was found that KLK8 was highly induced in the myocardium of mice with streptozotocin-induced diabetes. KLK8 deficiency attenuated diabetic cardiac fibrosis, and rescued the impaired cardiac function in diabetic mice. Small interfering RNA (siRNA)-mediated KLK8 knockdown significantly attenuated high glucose-induced endothelial damage and EndMT in human coronary artery endothelial cells (HCAECs). Diabetes-induced endothelial injury and cardiac EndMT were significantly alleviated in KLK8-deficient mice. In addition, transgenic overexpression of KLK8 led to interstitial and perivascular cardiac fibrosis, endothelial injury and EndMT in the heart. Adenovirus-mediated overexpression of KLK8 (Ad-KLK8) resulted in increases in endothelial cell damage, permeability and transforming growth factor (TGF)-beta1 release in HCAECs. KLK8 overexpression also induced EndMT in HCAECs, which was alleviated by a TGF-beta1-neutralizing antibody. A specificity protein-1 (Sp-1) consensus site was identified in the human KLK8 promoter and was found to mediate the high glucose-induced KLK8 expression. Mechanistically, it was identified that the vascular endothelial (VE)-cadherin/plakoglobin complex may associate with KLK8 in HCAECs. KLK8 cleaved the VE-cadherin extracellular domain, thus promoting plakoglobin nuclear translocation. Plakoglobin was required for KLK8-induced EndMT by cooperating with p53. KLK8 overexpression led to plakoglobin-dependent association of p53 with hypoxia inducible factor (HIF)-1alpha, which further enhanced the transactivation effect of HIF-1alpha on the TGF-beta1 promoter. KLK8 also induced the binding of p53 with Smad3, subsequently promoting pro-EndMT reprogramming via the TGF-beta1/Smad signaling pathway in HCAECs. The in vitro and in vivo findings further demonstrated that high glucose may promote plakoglobin-dependent cooperation of p53 with HIF-1alpha and Smad3, subsequently increasing the expression of TGF-beta1 and the pro-EndMT target genes of the TGF-beta1/Smad signaling pathway in a KLK8-dependent manner. Conclusions: The present findings uncovered a novel pro-EndMT mechanism during the pathogenesis of diabetic cardiac fibrosis via the upregulation of KLK8, and may contribute to the development of future KLK8-based therapeutic strategies for diabetic cardiomyopathy. CI - (c) The author(s). FAU - Du, Jian-Kui AU - Du JK AD - National Clinical Research Center for Geriatric Disorders and National International Joint Research Center for Medical Metabolomics, Xiangya Hospital, Central South University, Changsha, Hunan, China. AD - Department of Physiology, Navy Medical University, Shanghai, China. FAU - Yu, Qing AU - Yu Q AD - Department of Physiology, Navy Medical University, Shanghai, China. FAU - Liu, Yu-Jian AU - Liu YJ AD - School of Kinesiology, Shanghai University of Sport, Shanghai, China. FAU - Du, Shu-Fang AU - Du SF AD - Department of Physiology, Navy Medical University, Shanghai, China. FAU - Huang, Li-Yang AU - Huang LY AD - Department of Physiology, Navy Medical University, Shanghai, China. FAU - Xu, Dan-Hong AU - Xu DH AD - School of Kinesiology, Shanghai University of Sport, Shanghai, China. FAU - Ni, Xin AU - Ni X AD - National Clinical Research Center for Geriatric Disorders and National International Joint Research Center for Medical Metabolomics, Xiangya Hospital, Central South University, Changsha, Hunan, China. AD - Department of Physiology, Navy Medical University, Shanghai, China. FAU - Zhu, Xiao-Yan AU - Zhu XY AD - Department of Physiology, Navy Medical University, Shanghai, China. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20210220 PL - Australia TA - Theranostics JT - Theranostics JID - 101552395 RN - 0 (Hypoxia-Inducible Factor 1, alpha Subunit) RN - 0 (Smad3 Protein) RN - 0 (Transforming Growth Factor beta1) RN - 0 (gamma Catenin) RN - EC 3.4.21.- (KLK8 protein, human) RN - EC 3.4.21.- (Kallikreins) SB - IM MH - Animals MH - Cells, Cultured MH - Diabetes Mellitus, Experimental/*genetics/*pathology MH - Endothelium/pathology MH - Epithelial-Mesenchymal Transition/genetics MH - Fibrosis/*genetics/*pathology MH - Heart/physiology MH - Human Umbilical Vein Endothelial Cells/pathology MH - Humans MH - Hypoxia-Inducible Factor 1, alpha Subunit/genetics MH - Kallikreins/*genetics MH - Mice MH - Myocardium/pathology MH - Promoter Regions, Genetic/genetics MH - Signal Transduction/genetics MH - Smad3 Protein/genetics MH - Transforming Growth Factor beta1/metabolism MH - gamma Catenin/metabolism PMC - PMC7977470 OTO - NOTNLM OT - KLK8 OT - cardiac fibrosis OT - diabetic cardiomyopathy OT - endothelial-to-mesenchymal transition OT - plakoglobin COIS- Competing Interests: The authors have declared that no competing interest exists. EDAT- 2021/03/24 06:00 MHDA- 2021/07/30 06:00 PMCR- 2021/01/01 CRDT- 2021/03/23 06:56 PHST- 2020/05/21 00:00 [received] PHST- 2021/01/13 00:00 [accepted] PHST- 2021/03/23 06:56 [entrez] PHST- 2021/03/24 06:00 [pubmed] PHST- 2021/07/30 06:00 [medline] PHST- 2021/01/01 00:00 [pmc-release] AID - thnov11p4207 [pii] AID - 10.7150/thno.48530 [doi] PST - epublish SO - Theranostics. 2021 Feb 20;11(9):4207-4231. doi: 10.7150/thno.48530. eCollection 2021.