title: Novel molecular insights into RhoA GTPase-induced resistance to aqueous humor outflow through the trabecular meshwork.
abstract: Impaired drainage of aqueous humor through the trabecular meshwork (TM) culminating in increased intraocular pressure is a major risk factor for glaucoma, a leading cause of blindness worldwide. Regulation of aqueous humor drainage through the TM, however, is poorly understood. The role of RhoA GTPase-mediated actomyosin organization, cell adhesive interactions, and gene expression in regulation of aqueous humor outflow was investigated using adenoviral vector-driven expression of constitutively active mutant of RhoA (RhoAV14). Organ-cultured anterior segments from porcine eyes expressing RhoAV14 exhibited significant reduction of aqueous humor outflow. Cultured TM cells expressing RhoAV14 exhibited a pronounced contractile morphology, increased actin stress fibers, and focal adhesions and increased levels of phosphorylated myosin light chain (MLC), collagen IV, fibronectin, and laminin. cDNA microarray analysis of RNA extracted from RhoAV14-expressing human TM cells revealed a significant increase in the expression of genes encoding extracellular matrix (ECM) proteins, cytokines, integrins, cytoskeletal proteins, and signaling proteins. Conversely, various ECM proteins stimulated robust increases in phosphorylation of MLC, paxillin, and focal adhesion kinase and activated Rho GTPase and actin stress fiber formation in TM cells, indicating a potential regulatory feedback interaction between ECM-induced mechanical strain and Rho GTPase-induced isometric tension in TM cells. Collectively, these data demonstrate that sustained activation of Rho GTPase signaling in the aqueous humor outflow pathway increases resistance to aqueous humor outflow through the trabecular pathway by influencing the actomyosin assembly, cell adhesive interactions, and the expression of ECM proteins and cytokines in TM cells.
authors.affiliation: Dept. of Ophthalmology, Duke Univ. School of Medicine, 2351 Erwin Rd., Durham, NC 27710, USA.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Rupalatha
authors.initials: R
authors.lastname: Maddala
authors.forename: Ponugoti Vasantha
authors.initials: PV
authors.lastname: Rao
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D001082:Aqueous Humor / Q000201:enzymology*; D002448:Cell Adhesion; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D003599:Cytoskeleton / Q000201:enzymology*; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism; D022001:Focal Adhesions / Q000201:enzymology; D020869:Gene Expression Profiling; D018014:Gene Transfer Techniques; D006801:Humans; D007429:Intraocular Pressure; D009154:Mutation; D018994:Myosin Light Chains / Q000378:metabolism; D009924:Organ Culture Techniques; D010766:Phosphorylation; D022502:Stress Fibers / Q000201:enzymology; D013552:Swine; D013997:Time Factors; D014129:Trabecular Meshwork / Q000201:enzymology*; D015854:Up-Regulation; D020742:rhoA GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D000199:Actins; D016207:Cytokines; D016326:Extracellular Matrix Proteins; D018994:Myosin Light Chains; D020742:rhoA GTP-Binding Protein
references.citation: Genes Dev. 1997 Sep 15;11(18):2295-322
references.pmid: 9308960
references.citation: BioDrugs. 2007;21(3):167-77
references.pmid: 17516712
references.citation: Invest Ophthalmol Vis Sci. 2004 Jul;45(7):2263-71
references.pmid: 15223804
references.citation: Prog Retin Eye Res. 2005 Sep;24(5):612-37
references.pmid: 15919228
references.citation: Curr Opin Ophthalmol. 2006 Apr;17(2):168-74
references.pmid: 16552252
references.citation: FASEB J. 2006 May;20(7):811-27
references.pmid: 16675838
references.citation: Trends Cell Biol. 2006 Apr;16(4):213-23
references.pmid: 16529933
references.citation: Biochim Biophys Acta. 2005 Dec 30;1754(1-2):245-52
references.pmid: 16213195
references.citation: Nature. 1997 Oct 30;389(6654):990-4
references.pmid: 9353125
references.citation: Curr Opin Cell Biol. 2006 Oct;18(5):472-81
references.pmid: 16930976
references.citation: Am J Physiol Cell Physiol. 2003 Mar;284(3):C627-39
references.pmid: 12409284
references.citation: J Cell Biol. 1998 Apr 20;141(2):539-51
references.pmid: 9548730
references.citation: J Mol Med (Berl). 2002 Oct;80(10):629-38
references.pmid: 12395147
references.citation: Mol Vis. 2002 Mar 06;8:32-44
references.pmid: 11889464
references.citation: Lancet. 2004 May 22;363(9422):1711-20
references.pmid: 15158634
references.citation: Invest Ophthalmol Vis Sci. 1998 Dec;39(13):2649-58
references.pmid: 9856774
references.citation: Mol Vis. 2006 Sep 30;12:1117-26
references.pmid: 17093396
references.citation: Invest Ophthalmol Vis Sci. 2001 Apr;42(5):1029-37
references.pmid: 11274082
references.citation: Physiol Rev. 2003 Oct;83(4):1325-58
references.pmid: 14506307
references.citation: Am J Physiol Cell Physiol. 2004 Mar;286(3):C518-28
references.pmid: 14761883
references.citation: Invest Ophthalmol Vis Sci. 1999 Jan;40(1):74-81
references.pmid: 9888429
references.citation: Mol Vis. 2005 Sep 23;11:798-810
references.pmid: 16205625
references.citation: Nature. 2002 Dec 12;420(6916):629-35
references.pmid: 12478284
references.citation: Invest Ophthalmol Vis Sci. 2000 Mar;41(3):619-23
references.pmid: 10711672
references.citation: Arterioscler Thromb Vasc Biol. 2005 Sep;25(9):1767-75
references.pmid: 16002741
references.citation: Prog Retin Eye Res. 2003 Jul;22(4):435-63
references.pmid: 12742391
references.citation: Invest Ophthalmol Vis Sci. 1990 Nov;31(11):2384-8
references.pmid: 2243003
references.citation: Exp Eye Res. 2005 Jul;81(1):1-4
references.pmid: 15978248
references.citation: Acta Physiol Scand. 1998 Dec;164(4):483-93
references.pmid: 9887971
references.citation: Prog Retin Eye Res. 2000 May;19(3):271-95
references.pmid: 10749378
references.citation: Science. 1997 Jan 31;275(5300):668-70
references.pmid: 9005853
references.citation: Invest Ophthalmol Vis Sci. 2007 Mar;48(3):1191-200
references.pmid: 17325163
references.citation: Invest Ophthalmol Vis Sci. 2000 Dec;41(13):4163-8
references.pmid: 11095610
references.citation: Trends Pharmacol Sci. 2006 Feb;27(2):97-104
references.pmid: 16376997
references.citation: Am J Physiol. 1999 Aug;277(2):C330-42
references.pmid: 10444410
references.citation: Mol Vis. 2005 Apr 27;11:288-97
references.pmid: 15889013
references.citation: Invest Ophthalmol Vis Sci. 2006 Jan;47(1):226-34
references.pmid: 16384967
references.citation: Exp Eye Res. 2005 Feb;80(2):197-206
references.pmid: 15670798
references.citation: Scand J Med Sci Sports. 2005 Aug;15(4):223-30
references.pmid: 15998339
references.citation: Trends Pharmacol Sci. 2001 Jan;22(1):32-9
references.pmid: 11165670
references.citation: Mol Vis. 2004 Oct 07;10:750-7
references.pmid: 15496827
references.citation: FASEB J. 2006 Mar;20(3):536-8
references.pmid: 16396994
references.citation: Exp Eye Res. 1994 Dec;59(6):723-7
references.pmid: 7698265
references.citation: J Appl Physiol (1985). 2001 Jul;91(1):497-503
references.pmid: 11408468
references.citation: Graefes Arch Clin Exp Ophthalmol. 1997 Sep;235(9):551-2
references.pmid: 9342603
references.citation: Invest Ophthalmol Vis Sci. 2001 Jan;42(1):137-44
references.pmid: 11133858
references.citation: Surv Ophthalmol. 1996 Mar-Apr;40(5):379-90
references.pmid: 8779084
references.citation: Vascul Pharmacol. 2002 Nov;39(4-5):187-99
references.pmid: 12747959
references.citation: Invest Ophthalmol Vis Sci. 2005 Aug;46(8):2857-68
references.pmid: 16043860
references.citation: Invest Ophthalmol Vis Sci. 2002 Nov;43(11):3455-64
references.pmid: 12407156
references.citation: Prog Retin Eye Res. 1999 Jan;18(1):91-119
references.pmid: 9920500
references.citation: Invest Ophthalmol Vis Sci. 1998 Sep;39(10):1804-12
references.pmid: 9727403