D Fu1, M Wu, J Zhang, M Du, S Yang, S M Hammad, K Wilson, J Chen, T J Lyons. 1. Harold Hamm Diabetes Center and Section of Endocrinology, University of Oklahoma Health Sciences Center, 1000 N Lincoln Blvd, Suite 2900, Oklahoma City, OK 73104, USA.
Abstract
AIMS/HYPOTHESIS: In previous studies we have shown that extravasated, modified LDL is associated with pericyte loss, an early feature of diabetic retinopathy (DR). Here we sought to determine detailed mechanisms of this LDL-induced pericyte loss. METHODS: Human retinal capillary pericytes (HRCP) were exposed to 'highly-oxidised glycated' LDL (HOG-LDL) (a model of extravasated and modified LDL) and to 4-hydroxynonenal or 7-ketocholesterol (components of oxidised LDL), or to native LDL for 1 to 24 h with or without 1 h of pretreatment with inhibitors of the following: (1) the scavenger receptor (polyinosinic acid); (2) oxidative stress (N-acetyl cysteine); (3) endoplasmic reticulum (ER) stress (4-phenyl butyric acid); and (4) mitochondrial dysfunction (cyclosporin A). Oxidative stress, ER stress, mitochondrial dysfunction, apoptosis and autophagy were assessed using techniques including western blotting, immunofluorescence, RT-PCR, flow cytometry and TUNEL assay. To assess the relevance of the results in vivo, immunohistochemistry was used to detect the ER stress chaperon, 78 kDa glucose-regulated protein, and the ER sensor, activating transcription factor 6, in retinas from a mouse model of DR that mimics exposure of the retina to elevated glucose and elevated LDL levels, and in retinas from human participants with and without diabetes and DR. RESULTS: Compared with native LDL, HOG-LDL activated oxidative and ER stress in HRCP, resulting in mitochondrial dysfunction, apoptosis and autophagy. In a mouse model of diabetes and hyperlipidaemia (vs mouse models of either condition alone), retinal ER stress was enhanced. ER stress was also enhanced in diabetic human retina and correlated with the severity of DR. CONCLUSIONS/ INTERPRETATION: Cell culture, animal, and human data suggest that oxidative stress and ER stress are induced by modified LDL, and are implicated in pericyte loss in DR.
AIMS/HYPOTHESIS: In previous studies we have shown that extravasated, modified LDL is associated with pericyte loss, an early feature of diabetic retinopathy (DR). Here we sought to determine detailed mechanisms of this LDL-induced pericyte loss. METHODS:Human retinal capillary pericytes (HRCP) were exposed to 'highly-oxidised glycated' LDL (HOG-LDL) (a model of extravasated and modified LDL) and to 4-hydroxynonenal or 7-ketocholesterol (components of oxidised LDL), or to native LDL for 1 to 24 h with or without 1 h of pretreatment with inhibitors of the following: (1) the scavenger receptor (polyinosinic acid); (2) oxidative stress (N-acetyl cysteine); (3) endoplasmic reticulum (ER) stress (4-phenyl butyric acid); and (4) mitochondrial dysfunction (cyclosporin A). Oxidative stress, ER stress, mitochondrial dysfunction, apoptosis and autophagy were assessed using techniques including western blotting, immunofluorescence, RT-PCR, flow cytometry and TUNEL assay. To assess the relevance of the results in vivo, immunohistochemistry was used to detect the ER stress chaperon, 78 kDa glucose-regulated protein, and the ER sensor, activating transcription factor 6, in retinas from a mouse model of DR that mimics exposure of the retina to elevated glucose and elevated LDL levels, and in retinas from humanparticipants with and without diabetes and DR. RESULTS:Compared with native LDL, HOG-LDL activated oxidative and ER stress in HRCP, resulting in mitochondrial dysfunction, apoptosis and autophagy. In a mouse model of diabetes and hyperlipidaemia (vs mouse models of either condition alone), retinal ER stress was enhanced. ER stress was also enhanced in diabetichuman retina and correlated with the severity of DR. CONCLUSIONS/ INTERPRETATION:Cell culture, animal, and human data suggest that oxidative stress and ER stress are induced by modified LDL, and are implicated in pericyte loss in DR.
Authors: Umut Ozcan; Erkan Yilmaz; Lale Ozcan; Masato Furuhashi; Eric Vaillancourt; Ross O Smith; Cem Z Görgün; Gökhan S Hotamisligil Journal: Science Date: 2006-08-25 Impact factor: 47.728
Authors: Daniel J Klionsky; Hagai Abeliovich; Patrizia Agostinis; Devendra K Agrawal; Gjumrakch Aliev; David S Askew; Misuzu Baba; Eric H Baehrecke; Ben A Bahr; Andrea Ballabio; Bruce A Bamber; Diane C Bassham; Ettore Bergamini; Xiaoning Bi; Martine Biard-Piechaczyk; Janice S Blum; Dale E Bredesen; Jeffrey L Brodsky; John H Brumell; Ulf T Brunk; Wilfried Bursch; Nadine Camougrand; Eduardo Cebollero; Francesco Cecconi; Yingyu Chen; Lih-Shen Chin; Augustine Choi; Charleen T Chu; Jongkyeong Chung; Peter G H Clarke; Robert S B Clark; Steven G Clarke; Corinne Clavé; John L Cleveland; Patrice Codogno; María I Colombo; Ana Coto-Montes; James M Cregg; Ana Maria Cuervo; Jayanta Debnath; Francesca Demarchi; Patrick B Dennis; Phillip A Dennis; Vojo Deretic; Rodney J Devenish; Federica Di Sano; J Fred Dice; Marian Difiglia; Savithramma Dinesh-Kumar; Clark W Distelhorst; Mojgan Djavaheri-Mergny; Frank C Dorsey; Wulf Dröge; Michel Dron; William A Dunn; Michael Duszenko; N Tony Eissa; Zvulun Elazar; Audrey Esclatine; Eeva-Liisa Eskelinen; László Fésüs; Kim D Finley; José M Fuentes; Juan Fueyo; Kozo Fujisaki; Brigitte Galliot; Fen-Biao Gao; David A Gewirtz; Spencer B Gibson; Antje Gohla; Alfred L Goldberg; Ramon Gonzalez; Cristina González-Estévez; Sharon Gorski; Roberta A Gottlieb; Dieter Häussinger; You-Wen He; Kim Heidenreich; Joseph A Hill; Maria Høyer-Hansen; Xun Hu; Wei-Pang Huang; Akiko Iwasaki; Marja Jäättelä; William T Jackson; Xuejun Jiang; Shengkan Jin; Terje Johansen; Jae U Jung; Motoni Kadowaki; Chanhee Kang; Ameeta Kelekar; David H Kessel; Jan A K W Kiel; Hong Pyo Kim; Adi Kimchi; Timothy J Kinsella; Kirill Kiselyov; Katsuhiko Kitamoto; Erwin Knecht; Masaaki Komatsu; Eiki Kominami; Seiji Kondo; Attila L Kovács; Guido Kroemer; Chia-Yi Kuan; Rakesh Kumar; Mondira Kundu; Jacques Landry; Marianne Laporte; Weidong Le; Huan-Yao Lei; Michael J Lenardo; Beth Levine; Andrew Lieberman; Kah-Leong Lim; Fu-Cheng Lin; Willisa Liou; Leroy F Liu; Gabriel Lopez-Berestein; Carlos López-Otín; Bo Lu; Kay F Macleod; Walter Malorni; Wim Martinet; Ken Matsuoka; Josef Mautner; Alfred J Meijer; Alicia Meléndez; Paul Michels; Giovanni Miotto; Wilhelm P Mistiaen; Noboru Mizushima; Baharia Mograbi; Iryna Monastyrska; Michael N Moore; Paula I Moreira; Yuji Moriyasu; Tomasz Motyl; Christian Münz; Leon O Murphy; Naweed I Naqvi; Thomas P Neufeld; Ichizo Nishino; Ralph A Nixon; Takeshi Noda; Bernd Nürnberg; Michinaga Ogawa; Nancy L Oleinick; Laura J Olsen; Bulent Ozpolat; Shoshana Paglin; Glen E Palmer; Issidora Papassideri; Miles Parkes; David H Perlmutter; George Perry; Mauro Piacentini; Ronit Pinkas-Kramarski; Mark Prescott; Tassula Proikas-Cezanne; Nina Raben; Abdelhaq Rami; Fulvio Reggiori; Bärbel Rohrer; David C Rubinsztein; Kevin M Ryan; Junichi Sadoshima; Hiroshi Sakagami; Yasuyoshi Sakai; Marco Sandri; Chihiro Sasakawa; Miklós Sass; Claudio Schneider; Per O Seglen; Oleksandr Seleverstov; Jeffrey Settleman; John J Shacka; Irving M Shapiro; Andrei Sibirny; Elaine C M Silva-Zacarin; Hans-Uwe Simon; Cristiano Simone; Anne Simonsen; Mark A Smith; Katharina Spanel-Borowski; Vickram Srinivas; Meredith Steeves; Harald Stenmark; Per E Stromhaug; Carlos S Subauste; Seiichiro Sugimoto; David Sulzer; Toshihiko Suzuki; Michele S Swanson; Ira Tabas; Fumihiko Takeshita; Nicholas J Talbot; Zsolt Tallóczy; Keiji Tanaka; Kozo Tanaka; Isei Tanida; Graham S Taylor; J Paul Taylor; Alexei Terman; Gianluca Tettamanti; Craig B Thompson; Michael Thumm; Aviva M Tolkovsky; Sharon A Tooze; Ray Truant; Lesya V Tumanovska; Yasuo Uchiyama; Takashi Ueno; Néstor L Uzcátegui; Ida van der Klei; Eva C Vaquero; Tibor Vellai; Michael W Vogel; Hong-Gang Wang; Paul Webster; John W Wiley; Zhijun Xi; Gutian Xiao; Joachim Yahalom; Jin-Ming Yang; George Yap; Xiao-Ming Yin; Tamotsu Yoshimori; Li Yu; Zhenyu Yue; Michisuke Yuzaki; Olga Zabirnyk; Xiaoxiang Zheng; Xiongwei Zhu; Russell L Deter Journal: Autophagy Date: 2007-11-21 Impact factor: 16.016