title: Shear stress-mediated chromatin remodeling provides molecular basis for flow-dependent regulation of gene expression.
abstract: Shear stress (SS), the tangential component of hemodynamic forces, modulates the expression of several genes in endothelial cells. However, no information is available about its effect on chromatin structure, which plays a key role in gene transcription. In this study, a link between SS and chromatin remodeling was established in human umbilical vein endothelial cells (HUVECs). HUVECs were exposed to SS of 10 dyne/cm2 per second, in the presence or absence of the histone deacetylase inhibitor trichostatin A, and assayed for histone H3 and histone H4 modifications. SS induced histone H3 serine phosphorylation at position 10 (S10) and lysine acetylation at position 14 (K14) but required trichostatin A to induce H3 phosphoacetylation and H4 acetylation. The phosphatidylinositol 3-kinase inhibitor wortmannin and the mitogen-activated protein kinase inhibitor PD98059 decreased SS-dependent histone H3 phosphorylation, without affecting its acetylation; the p38 inhibitor SB203580 reduced both H3 phosphorylation and acetylation, whereas the protein kinase A inhibitor PKI-tide reduced histone H3 acetylation. Remarkably, the abrogation of histone acetylation inhibited SS-dependent c-fos expression. SS also activated ribosomal S6 kinase-2 and mitogen- and stress-activated kinase-1 protein kinases and promoted the formation of a cAMP-responsive element-binding protein (CREB)/CREB-binding protein complex, providing the molecular basis for the increase in histone acetyltransferase activity observed in HUVECs exposed to SS. Finally, the effect of SS on chromatin remodeling was examined. In HUVECs exposed to SS, chromatin within c-fos and c-jun promoters was specifically immunoprecipitated by an antibody against acetylated histone H3 on K14. These results indicate that SS induces posttransduction modifications of histones; this is an early step toward the flow-dependent regulation of gene expression.
authors.affiliation: Laboratorio di Biologia Vascolare e Terapia Genica, Centro Cardiologico Fondazione I. Monzino, IRCCS, Milan, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Illi
authors.forename: Simona
authors.initials: S
authors.lastname: Nanni
authors.forename: Alessandro
authors.initials: A
authors.lastname: Scopece
authors.forename: Antonella
authors.initials: A
authors.lastname: Farsetti
authors.forename: Paolo
authors.initials: P
authors.lastname: Biglioli
authors.forename: Maurizio C
authors.initials: MC
authors.lastname: Capogrossi
authors.forename: Carlo
authors.initials: C
authors.lastname: Gaetano
mesh_terms: D000107:Acetylation / Q000187:drug effects; D000123:Acetyltransferases / Q000378:metabolism; D050882:CREB-Binding Protein; D002478:Cells, Cultured; D002843:Chromatin / Q000378:metabolism*; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D004730:Endothelium, Vascular / Q000166:cytology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D016758:Genes, jun; D051548:Histone Acetyltransferases; D056572:Histone Deacetylase Inhibitors; D006655:Histone Deacetylases / Q000378:metabolism; D006657:Histones / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D009687:Nuclear Proteins / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation / Q000187:drug effects; D011401:Promoter Regions, Genetic; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism; D012212:Rheology / Q000379:methods; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D013314:Stress, Mechanical; D015534:Trans-Activators / Q000378:metabolism; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D002843:Chromatin; D017362:Cyclic AMP Response Element-Binding Protein; D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D006657:Histones; D006877:Hydroxamic Acids; D009687:Nuclear Proteins; D000081082:Phosphoinositide-3 Kinase Inhibitors; D016760:Proto-Oncogene Proteins c-fos; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; C012589:trichostatin A; D000123:Acetyltransferases; D050882:CREB-Binding Protein; C494363:CREBBP protein, human; D051548:Histone Acetyltransferases; D038744:Ribosomal Protein S6 Kinases, 90-kDa; C116919:mitogen and stress-activated protein kinase 1; C069330:ribosomal protein S6 kinase, 90kDa, polypeptide 3; D017868:Cyclic AMP-Dependent Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D006655:Histone Deacetylases