title: Myricetin inhibits advanced glycation end product (AGE)-induced migration of retinal pericytes through phosphorylation of ERK1/2, FAK-1, and paxillin in vitro and in vivo.
abstract: Advanced glycation end products (AGE) have been implicated in the development of diabetic retinopathy. Characterization of the early stages of diabetic retinopathy is retinal pericytes loss, which is the result of pericytes migration. In this study, we investigated the pathological mechanisms of AGE on the migration of retinal pericytes and confirmed the inhibitory effect of myricetin on migration in vitro and in vivo. Migration assays of bovine retinal pericytes (BRP) were induced using AGE-BSA and phosphorylation of Src, ERK1/2, focal adhesion kinase (FAK-1) and paxillin were determined using immunoblot analysis. Sprague-Dawley rats (6 weeks old) were injected intravitreally with AGE-BSA and morphological and immunohistochemical analysis of p-FAK-1 and p-paxillin were performed in the rat retina. Immunoblot analysis and siRNA transfection were used to study the molecular mechanism of myricetin on BRP migration. AGE-BSA increased BRP migration in a dose-dependent manner via receptor for AGEs (RAGE)-dependent activation of the Src kinase-ERK1/2 pathway. AGE-BSA-induced migration was inhibited by an ERK1/2 specific inhibitor (PD98059), but not by p38 and Jun N-terminal kinase inhibitors. AGE-BSA increased FAK-1 and paxillin phosphorylation in a dose- and time-dependent manner. These increases were attenuated by PD98059 and ERK1/2 siRNA. Phosphorylation of FAK-1 and paxillin was increased in response to AGE-BSA-induced migration of rat retinal pericytes. Myricetin strongly inhibited ERK1/2 phosphorylation and significantly suppressed pericytes migration in AGE-BSA-injected rats. Our results demonstrate that AGE-BSA participated in the pathophysiology of retinal pericytes migration likely through the RAGE-Src-ERK1/2-FAK-1-paxillin signaling pathway. Furthermore, myricetin suppressed phosphorylation of ERK 1/2-FAK-1-paxillin and inhibited pericytes migration.
authors.affiliation: Korean Medicine-Based Herbal Drug Development Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), 1672 Yuseongdae-ro, Yuseong-gu, Daejeon, South Korea. Electronic address: ykim@kiom.re.kr.
authors.forename: Young Sook
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Korean Medicine-Based Herbal Drug Development Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), 1672 Yuseongdae-ro, Yuseong-gu, Daejeon, South Korea.
authors.forename: Junghyun
authors.initials: J
authors.lastname: Kim
authors.affiliation: Korean Medicine-Based Herbal Drug Development Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), 1672 Yuseongdae-ro, Yuseong-gu, Daejeon, South Korea.
authors.forename: Ki Mo
authors.initials: KM
authors.lastname: Kim
authors.affiliation: Korean Medicine-Based Herbal Drug Development Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), 1672 Yuseongdae-ro, Yuseong-gu, Daejeon, South Korea.
authors.forename: Dong Ho
authors.initials: DH
authors.lastname: Jung
authors.affiliation: Korean Medicine-Based Herbal Drug Development Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), 1672 Yuseongdae-ro, Yuseong-gu, Daejeon, South Korea.
authors.forename: Sojin
authors.initials: S
authors.lastname: Choi
authors.affiliation: Korean Medicine-Based Herbal Drug Development Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), 1672 Yuseongdae-ro, Yuseong-gu, Daejeon, South Korea.
authors.forename: Chan-Sik
authors.initials: CS
authors.lastname: Kim
authors.affiliation: Korean Medicine-Based Herbal Drug Development Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), 1672 Yuseongdae-ro, Yuseong-gu, Daejeon, South Korea. Electronic address: jskim@kiom.re.kr.
authors.forename: Jin Sook
authors.initials: JS
authors.lastname: Kim
mesh_terms: D000818:Animals; D002417:Cattle; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000494:pharmacology*; D051417:Focal Adhesion Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017127:Glycation End Products, Advanced / Q000008:administration & dosage*; D058449:Intravitreal Injections; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D008297:Male; D051419:Paxillin / Q000037:antagonists & inhibitors / Q000378:metabolism*; D020286:Pericytes / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012710:Serum Albumin, Bovine / Q000008:administration & dosage*
chemical_list: D005419:Flavonoids; D017127:Glycation End Products, Advanced; D051419:Paxillin; C081628:advanced glycation end products-bovine serum albumin; D012710:Serum Albumin, Bovine; C040015:myricetin; D051417:Focal Adhesion Kinase 1
keywords: Focal adhesion kinase-1; Migration; Myricetin; Paxillin; Retinal pericytes