PMID- 35490835 OWN - NLM STAT- MEDLINE DCOM- 20220621 LR - 20221005 IS - 1096-0007 (Electronic) IS - 0014-4835 (Linking) VI - 220 DP - 2022 Jul TI - Inhibition of Drp1 ameliorates diabetic retinopathy by regulating mitochondrial homeostasis. PG - 109095 LID - S0014-4835(22)00175-0 [pii] LID - 10.1016/j.exer.2022.109095 [doi] AB - Diabetic retinopathy (DR) is a potentially blinding complication resulting from diabetes mellitus (DM). Retinal vascular endothelial cells (RMECs) dysfunction occupies an important position in the pathogenesis of DR, and mitochondrial disorders play a vital role in RMECs dysfunction. However, the detailed mechanisms underlying DR-induced mitochondrial disorders in RMECs remain elusive. In the present study, we used High glucose (HG)-induced RMECs in vitro and streptozotocin (STZ)-induced Sprague-Dawley rats in vivo to explore the related mechanisms. We found that HG-induced mitochondrial dysfunction via mitochondrial Dynamin-related protein 1(Drp1)-mediated mitochondrial fission. Drp1 inhibitor, Mdivi-1, rescued HG-induced mitochondrial dysfunction. Protein Kinase Cdelta (PKCdelta) could induce phosphorylation of Drp1, and we found that HG induced phosphorylation of PKCdelta. PKCdelta inhibitor (Go 6983) or PKCdelta siRNA reversed HG-induced phosphorylation of Drp1 and further mitochondrial dysfunction. The above studies indicated that HG increases mitochondrial fission via promoting PKCdelta/Drp1 signaling. Drp1 induces excessive mitochondrial fission and produces damaged mitochondrial, and mitophagy plays a key role in clearing damaged mitochondrial. Our study showed that HG suppressed mitophagy via inhibiting LC3B-II formation and p62 degradation. 3-MA (autophagy inhibitor) aggravated HG-induced RMECs damage, while rapamycin (autophagy agonist) rescued the above phenomenon. Further studies were identified that HG inhibited mitophagy by down-regulation of the PINK1/Parkin signaling pathway, and PINK1 siRNA aggravated HG-induced RMECs damage. Further in-depth study, we propose that Drp1 promotion of Hexokinase II (HK-II) separation from mitochondria, thus inhibiting HK-II-PINK1-mediated mitophagy. In vivo, we found that intraretinal microvascular abnormalities (IRMA), including retinal vascular leakage, acellular capillaries, and apoptosis were increased in STZ-induced DR rats, which were reversed by pretreatment with Mdivi-1 or Rapamycin. Altogether, our findings provide new insight into the mechanisms underlying the regulation of mitochondrial homeostasis and provide a potential treatment strategy for Diabetic retinopathy. CI - Copyright (c) 2022 Elsevier Ltd. All rights reserved. FAU - Zhang, Meng-Yuan AU - Zhang MY AD - Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, PR China. FAU - Zhu, Lingpeng AU - Zhu L AD - Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, PR China. FAU - Bao, Xun AU - Bao X AD - Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, PR China. FAU - Xie, Tian-Hua AU - Xie TH AD - Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, PR China. FAU - Cai, Jiping AU - Cai J AD - Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, PR China. FAU - Zou, Jian AU - Zou J AD - Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, PR China. FAU - Wang, Wenjuan AU - Wang W AD - Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, PR China. FAU - Gu, Shun AU - Gu S AD - Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, PR China. FAU - Li, Yan AU - Li Y AD - Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, PR China. FAU - Li, Hong-Ying AU - Li HY AD - Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, PR China. FAU - Yao, Yong AU - Yao Y AD - Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, PR China; Department of Ophthalmology, The Affiliated Wuxi No.2 People's Hospital of Nanjing Medical University, Wuxi, PR China. Electronic address: yongyao@njmu.edu.cn. FAU - Wei, Ting-Ting AU - Wei TT AD - Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, PR China. Electronic address: tingtingwei@njmu.edu.cn. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20220428 PL - England TA - Exp Eye Res JT - Experimental eye research JID - 0370707 RN - 0 (RNA, Small Interfering) RN - EC 2.7.- (Protein Kinases) RN - EC 3.6.5.5 (Dnm1l protein, rat) RN - EC 3.6.5.5 (Dynamins) RN - W36ZG6FT64 (Sirolimus) SB - IM MH - Animals MH - *Diabetes Mellitus/metabolism MH - *Diabetic Retinopathy/metabolism MH - *Dynamins/antagonists & inhibitors/metabolism MH - Endothelial Cells/metabolism MH - Homeostasis MH - *Mitochondria/metabolism MH - Protein Kinases/genetics/metabolism MH - RNA, Small Interfering MH - Rats MH - Rats, Sprague-Dawley MH - Sirolimus OTO - NOTNLM OT - Diabetic retinopathy OT - Drp1 OT - Mitochondrial fission OT - Mitophagy OT - PINK1 EDAT- 2022/05/02 06:00 MHDA- 2022/06/22 06:00 CRDT- 2022/05/01 19:25 PHST- 2021/12/16 00:00 [received] PHST- 2022/04/06 00:00 [revised] PHST- 2022/04/25 00:00 [accepted] PHST- 2022/05/02 06:00 [pubmed] PHST- 2022/06/22 06:00 [medline] PHST- 2022/05/01 19:25 [entrez] AID - S0014-4835(22)00175-0 [pii] AID - 10.1016/j.exer.2022.109095 [doi] PST - ppublish SO - Exp Eye Res. 2022 Jul;220:109095. doi: 10.1016/j.exer.2022.109095. Epub 2022 Apr 28.