title: Repression of choroidal neovascularization through actin cytoskeleton pathways by microRNA-24.
abstract: Actin cytoskeleton is critical for cell motility and division, both of which are important for angiogenesis. MicroRNAs (miRNA/miR) are emerging as pivotal modulators of vascular development and disease. How miRNAs regulate actin cytoskeleton dynamics in endothelial cells (EC) and neovascularization is still unclear. Here, we report that miR-24 regulates actin dynamics in ECs through targeting multiple members downstream of Rho signaling, including Pak4, Limk2, and Diaph1 proteins. Overexpression of miR-24 in ECs blocks stress fiber and lamellipodia formation, represses EC migration, proliferation, and tube formation in vitro, as well as angiogenesis in an ex vivo aortic ring assay. Moreover, subretinal delivery of miR-24 mimics represses laser-induced choroidal neovascularization (CNV) in vivo. Mechanistically, knockdown of miR-24 target protein LIMK2 or PAK4 inhibits stress fiber formation and tube formation in vitro, mimicking miR-24 overexpression phenotype in angiogenesis, while overexpression of LIMK2 and PAK4 by adenoviruses partially rescued the tube formation defects in miR-24 overexpressing ECs. Taken together, these findings suggest that miR-24 represses angiogenesis by simultaneously regulating multiple components in the actin cytoskeleton pathways. Manipulation of actin cytoskeleton pathways by miR-24 may represent an attractive therapeutic solution for the treatment of wet age-related macular degeneration (AMD) and other vascular diseases.
authors.affiliation: Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana, USA.
authors.forename: Qinbo
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana, USA.
authors.forename: Chastain
authors.initials: C
authors.lastname: Anderson
authors.affiliation: Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana, USA.
authors.forename: Fiona
authors.initials: F
authors.lastname: Inglis
authors.affiliation: Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Ashwath
authors.initials: A
authors.lastname: Jayagopal
authors.affiliation: Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana, USA; Department of Ophthalmology, Tulane University, New Orleans, Louisiana, USA. Electronic address: swang1@tulane.edu.
authors.forename: Shusheng
authors.initials: S
authors.lastname: Wang
mesh_terms: D020413:3' Untranslated Regions; D008841:Actin Cytoskeleton / Q000235:genetics* / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D020256:Choroidal Neovascularization / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D042783:Endothelial Cells / Q000378:metabolism; D005786:Gene Expression Regulation; D020868:Gene Silencing; D006801:Humans; D054461:Lim Kinases / Q000235:genetics; D008297:Male; D051379:Mice; D035683:MicroRNAs / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008954:Models, Biological; D010641:Phenotype; D034622:RNA Interference; D015398:Signal Transduction; D054462:p21-Activated Kinases / Q000235:genetics
chemical_list: D020413:3' Untranslated Regions; C543845:MIRN24 microRNA, human; D035683:MicroRNAs; C116367:PAK4 protein, human; C102895:LIMK2 protein, human; D054461:Lim Kinases; D054462:p21-Activated Kinases