Thrombin Modulates the Expression of a Set of Genes Including Thrombospondin-1 in Human Microvascular Endothelial Cells

Thrombospondin-1 (THBS1) is a large extracellular matrix glycoprotein that affects vasculature systems such as platelet activation, angiogenesis, and wound healing. Increases in THBS1 expression have been liked to disease states including tumor progression, atherosclerosis, and arthritis. The present study focuses on the effects of thrombin activation of the G-protein-coupled, protease-activated receptor-1 (PAR-1) on THBS1 gene expression in the microvascular endothelium. Thrombin-induced changes in gene expression were characterized by microarray analysis of ∼11,000 different human genes in human microvascular endothelial cells (HMEC-1). Thrombin induced the expression of a set of at least 65 genes including THBS1. Changes in THBS1 mRNA correlated with an increase in the extracellular THBS1 protein concentration. The PAR-1-specific agonist peptide (TFLLRNK-PDK) mimicked thrombin stimulation of THBS1 expression, suggesting that thrombin signaling is through PAR-1. Further studies showed THBS1 expression was sensitive to pertussis toxin and protein kinase C inhibition indicating Gi/o- and Gq-mediated pathways. THBS1 up-regulation was also confirmed in human umbilical vein endothelial cells stimulated with thrombin. Analysis of the promoter region of THBS1 and other genes of similar expression profile identified from the microarray predicted an EBOX/EGRF transcription model. Expression of members of each family, MYC and EGR1, respectively, correlated with THBS1 expression. These results suggest thrombin formed at sites of vascular injury increases THBS1 expression into the extracellular matrix via activation of a PAR-1, Gi/o, Gq, EBOX/EGRF-signaling cascade, elucidating regulatory points that may play a role in increased THBS1 expression in disease states. Thrombospondin-1 (THBS1) is a large extracellular matrix glycoprotein that affects vasculature systems such as platelet activation, angiogenesis, and wound healing. Increases in THBS1 expression have been liked to disease states including tumor progression, atherosclerosis, and arthritis. The present study focuses on the effects of thrombin activation of the G-protein-coupled, protease-activated receptor-1 (PAR-1) on THBS1 gene expression in the microvascular endothelium. Thrombin-induced changes in gene expression were characterized by microarray analysis of ∼11,000 different human genes in human microvascular endothelial cells (HMEC-1). Thrombin induced the expression of a set of at least 65 genes including THBS1. Changes in THBS1 mRNA correlated with an increase in the extracellular THBS1 protein concentration. The PAR-1-specific agonist peptide (TFLLRNK-PDK) mimicked thrombin stimulation of THBS1 expression, suggesting that thrombin signaling is through PAR-1. Further studies showed THBS1 expression was sensitive to pertussis toxin and protein kinase C inhibition indicating Gi/o- and Gq-mediated pathways. THBS1 up-regulation was also confirmed in human umbilical vein endothelial cells stimulated with thrombin. Analysis of the promoter region of THBS1 and other genes of similar expression profile identified from the microarray predicted an EBOX/EGRF transcription model. Expression of members of each family, MYC and EGR1, respectively, correlated with THBS1 expression. These results suggest thrombin formed at sites of vascular injury increases THBS1 expression into the extracellular matrix via activation of a PAR-1, Gi/o, Gq, EBOX/EGRF-signaling cascade, elucidating regulatory points that may play a role in increased THBS1 expression in disease states. Thrombospondin-1 (THBS1) 1The abbreviations used are: THBS1, thrombospondin-1; PAR, protease-activated receptor; HUVEC, human umbilical vein endothelial cell; HMEC-1, human microvascular endothelial cells; Bis I, bisindolylmaleimide I hydrochloride; TK, TFLLRNKPDK; PBS, phosphate-buffered saline; RT, real-time; GAPDH, glyceraldehydes-3-phosphate dehydrogenase; PTX, pertussis toxin; PLAT, plasminogen activator; ELISA, enzyme-linked immunosorbent assay; ROCK, Rho kinase. is a large (450 kDa) glycoprotein that is released into the extracellular matrix by several cell types. First discovered in platelets as a thrombin-sensitive protein (1Baenziger N.L. Brodie G.N. Majerus P.W. Proc. Natl. Acad. Sci. U. S. A. 1971; 68: 240-243Crossref PubMed Scopus (270) Google Scholar), THBS1 was later shown to be a major component of platelet α-granules, comprising some 25% of the total protein (2Esemuede N. Lee T. Pierre-Paul D. Sumpio B.E. Gahtan V. J. Surg. Res. 2004; 122: 135-142Abstract Full Text Full Text PDF PubMed Scopus (104) Google Scholar). Once released, THBS1 exerts various functions on the vascular system under physiological and pathophysiological conditions causing platelet activation (3Trumel C. Plantavid M. Levy-Toledano S. Ragab A. Caen J.P. Aguado E. Malissen B. Payrastre B. J. Thromb. Haemost. 2003; 1: 320-329Crossref PubMed Scopus (15) Google Scholar, 4Bonnefoy A. Hantgan R. Legrand C. Frojmovic M.M. J. Biol. Chem. 2001; 276: 5605-5612Abstract Full Text Full Text PDF PubMed Scopus (61) Google Scholar) and adhesion (5Jurk K. Clemetson K.J. de Groot P.G. Brodde M.F. Steiner M. Savion N. Varon D. Sixma J.J. Van Aken H. Kehrel B.E. FASEB J. 2003; 17: 1490-1492Crossref PubMed Scopus (132) Google Scholar) in addition to endothelial cell adhesion (6Morandi V. Fauvel-Lafeve F. Legrand C. Legrand Y.J. In Vitro Cell. Dev. Biol. Anim. 1993; 29: 585-591Crossref Scopus (17) Google Scholar), promotion of angiogenesis (7Lawler J. Sunday M. Thibert V. Duquette M. George E.L. Rayburn H. Hynes R.O. J. Clin. Investig. 1998; 101: 982-992Crossref PubMed Scopus (393) Google Scholar), and inhibition of angiogenesis (8Tolsma S.S. Stack M.S. Bouck N. Microvasc. Res. 1997; 54: 13-26Crossref PubMed Scopus (51) Google Scholar), wound healing (9Reed M.J. Puolakkainen P. Lane T.F. Dickerson D. Bornstein P. Sage E.H. J. Histochem. Cytochem. 1993; 41: 1467-1477Crossref PubMed Scopus (198) Google Scholar) as well as pathological states such as tumor progression and metastasis (10Roberts D.D. FASEB J. 1996; 10: 1183-1191Crossref PubMed Scopus (244) Google Scholar, 11Tuszynski G.P. Smith M. Rothman V.L. Capuzzi D.M. Joseph R.R. Katz J. Besa E.C. Treat J. Switalska H.I. Thromb. Haemostasis. 1992; 67: 607-611Crossref PubMed Scopus (75) Google Scholar). THBS1 is important not only in cancer progression but also in inflammatory autoimmune diseases such as rheumatoid arthritis (12Vallejo A.N. Mugge L.O. Klimiuk P.A. Weyand C.M. Goronzy J.J. J. Immunol. 2000; 164: 2947-2954Crossref PubMed Scopus (102) Google Scholar). Under normal conditions basal THBS1 expression is negligible. However, increased THBS1 expression has been linked to pathophysiological states such as atherosclerotic lesions (13Wight T.N. Raugi G.J. Mumby S.M. Bornstein P. J. Histochem. Cytochem. 1985; 33: 295-302Crossref PubMed Scopus (220) Google Scholar), vascular smooth muscle cell hyperplasia (14Raugi G.J. Mullen J.S. Bark D.H. Okada T. Mayberg M.R. Am. J. Pathol. 1990; 137: 179-185PubMed Google Scholar), and hypertension (15Botney M.D. Kaiser L.R. Cooper J.D. Mecham R.P. Parghi D. Roby J. Parks W.C. Am. J. Pathol. 1992; 140: 357-364PubMed Google Scholar). The mechanism by which THBS1 is up-regulated in disease states, however, is not well understood. Here we demonstrate that thrombin, a key player involved in coagulation, inflammation, and wound healing as well as in disease states such as atherosclerosis, can regulate THBS1 expression in endothelial cells. Thrombin activates a unique class of G-protein-coupled receptors called protease-activated receptors (PARs) by binding to and cleaving the amino-terminal exodomain of the receptor to unmask a new terminus that functions as a tethered ligand, binding intramolecularly to the body of the receptor (16Vu T.K. Hung D.T. Wheaton V.I. Coughlin S.R. Cell. 1991; 64: 1057-1068Abstract Full Text PDF PubMed Scopus (2778) Google Scholar, 17Vu T.K. Wheaton V.I. Hung D.T. Charo I. Coughlin S.R. Nature. 1991; 353: 674-677Crossref PubMed Scopus (503) Google Scholar, 18Chen J. Ishii M. Wang L. Ishii K. Coughlin S.R. J. Biol. Chem. 1994; 269: 16041-16045Abstract Full Text PDF PubMed Google Scholar). Four members of this receptor family have been cloned thus far (19Hollenberg M.D. 54: PubMed Scopus Google Scholar). signaling in human platelets is to be via and and the (19Hollenberg M.D. 54: PubMed Scopus Google Scholar) the in the S.R. Nature. 2000; PubMed Scopus Google Scholar, S.R. E. J. Clin. Investig. 2003; PubMed Scopus (220) Google Scholar). to members of the Gi/o, Gq, and D.T. T.K. Coughlin S.R. J. Biol. Chem. 1992; Full Text PDF PubMed Google Scholar, S. K. Proc. Natl. Acad. Sci. U. S. A. 1994; PubMed Scopus Google Scholar, A. A. T. J. Biol. Chem. 2001; 276: Full Text Full Text PDF PubMed Scopus Google Scholar, C. A. A. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar), activation of can to of various signaling which in cell and activation, and and studies on in endothelial cells have been to human umbilical vein endothelial cell M. A. PubMed Scopus Google Scholar, S. S. de Groot P.G. E. H. PubMed Scopus Google Scholar, L. A. P. J. Biol. Chem. 2004; Full Text Full Text PDF PubMed Scopus Google Scholar, T. K. M. M.R. N. T. H. T. T. W.C. J. Biol. Chem. 2004; Full Text Full Text PDF PubMed Scopus Google Scholar) However, endothelial cell in and signaling and microvascular endothelial cells and in signaling and protein expression Immunol. PubMed Scopus Google Scholar, A. J. Fauvel-Lafeve F. Legrand C. Thromb. Haemostasis. 2001; PubMed Scopus Google Scholar, I. S. D. L. T. I. Res. PubMed Scopus (244) Google Scholar, M. D. T. FASEB J. 2003; 17: PubMed Scopus Google Scholar). study changes in transcription that from thrombin in microvascular endothelial we have to studies in the human microvascular endothelial cell (HMEC-1). a similar to V. K. Microvasc. Res. 64: PubMed Scopus Google Scholar) and a set of that to to C. A. A. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). on microvascular endothelial cells the of THBS1 in cells such as in cancer and wound healing with Here we the effects of thrombin on THBS1 gene expression in a THBS1 to be up-regulated in mRNA and protein in to thrombin. up-regulation of THBS1 was pertussis indicating a signaling of protein kinase C also THBS1 expression, a Gq-mediated signaling a mechanism by which THBS1 may be up-regulated at sites of vascular injury and in disease states. cell were from bisindolylmaleimide I pertussis and were from The agonist peptide was from the present studies a human microvascular endothelial cell that was was used from E. The cells were in with and in an of at The cells were at and with of the studies cell of were in with endothelial and were in and used and were to to and were with human thrombin and cell were with by the addition of the from cell and in mRNA was the the with an and by and were used microarray and of and to were by the on a of total from and were into the and into the The were the The was with a of 25% and and and at on a human The in from the microarray used in and the genes in the to were each in and were from each on the at and and in each and each were from The were and were to a and genes region by genes The used was in of used points from the genes the set was a by correlated the with with of to a were by the to only that a this only the gene that from that have the was by a on to the of to be by each by total of by the was to the genes of into on expression The were that the in each was from of the other the this unique of genes that were up-regulated in a were The by the genes of into a of on the in the gene Four were the expression at the of each of to through the genes were to the with the The was the of the genes been the of the was and the was the of been was used to and promoter was used to promoter the genes of each were the of the matrix with different were of to the and was used to the promoter of not into a was used to the each of the 65 genes from the and were from was with were at at by at and at was used on an to human as well as the glyceraldehydes-3-phosphate as the used were were in a total of with the of and by with of and and of were with of in total each correlated with of each analysis and were the K.J. 2001; PubMed Scopus Google Scholar). was in and were and of plasminogen THBS1, PAR-1, and by used were from and and THBS1 and THBS1 and and MYC and MYC and and and of THBS1 in were with THBS1 from human platelets at The were with and with in at the were with of and THBS1 and and various of human THBS1 cell was to each well and at the were with and and an with and in were and to at The were as and the and was and a The was by the addition at was on a was in and at least as was by C. I. Proc. Natl. Acad. Sci. U. S. A. 1992; PubMed Scopus Google Scholar). were from were in by cells were at and to The and were to a of was by a to the and large The the and the large was by a and by a The the of the and the to different in the of the the the were were with a of inhibition of Rho kinase stimulation by thrombin. not of by pertussis toxin was as R. J. Biol. Chem. 1992; Full Text PDF PubMed Google Scholar, Lee Lee E.H. Lee J. Cell. 2001; PubMed Scopus Google Scholar, M.M. M. 1997; Google Scholar). cells were to in and with pertussis toxin were and to a of in in the of to the of toxin with phosphate-buffered were in and was by through a was by were to and were by were in of and total protein was protein to the was by in at of was with in and in a total of were to at were by the addition of of were by and in of were by and by Thrombin the Expression THBS1 and in genes expression is by thrombin stimulation in microvascular endothelial a microarray were The used to the by of ∼11,000 different human were stimulated with a of thrombin, was from and cells at and thrombin and were to the The was and to under the ∼11,000 genes only including THBS1, showed and in expression cells were by thrombin. is a of the expression of the 65 genes a of the and increases the 65 genes identified were up-regulated at each of the were genes expression was gene was into to expression a is an expression of the of members of each the of the of different genes PLAT, cell J. Cell. PubMed Scopus Google Scholar), protein and receptor such as region protein and also in this from each gene of the were and transcription binding sites were These transcription were to that transcription of transcription binding which have been shown to in and were identified in of the promoter Analysis of identified The transcription family in the was genes including protein and gene family, of this transcription such as promoter binding protein and similar analysis was the genes of the transcription genes into including some well characterized of the vascular plasminogen plasminogen receptor and the protein as well as THBS1. analysis was the genes of and were the transcription some of which by functions in the signaling of gene in tumor protein and such as and were also as well as the analysis was the genes of the transcription Thrombin of THBS1 Expression by the microarray results THBS1 and a of other was were thrombin the of THBS1 Thrombin induced THBS1, PLAT, and by and These well with the microarray of and respectively, In expression of and was via and to be induced by and These studies that expression in analysis A. H. R. T. C. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar) and demonstrate that thrombin can expression. These results suggest to the on the used in the present the results were the to the of THBS1 cells that THBS1 into the extracellular matrix can with physiological binding the mechanism that has not been a THBS1 transcription and into has been J. Clin. PubMed Scopus Google Scholar, G.J. Mumby S.M. D. Bornstein P. J. Biol. PubMed Scopus Google Scholar). that the increase in THBS1 mRNA correlated with an increase protein expression and to the of THBS1 released into the a was were with thrombin, and the were as and as under and from cells of THBS1 with cells. PAR-1, and in HMEC-1, is can in signaling H. D. C. T. Coughlin S.R. Nature. 1997; PubMed Scopus Google Scholar, N. M. M.J. J. Biol. Chem. 2000; Full Text Full Text PDF PubMed Scopus Google Scholar, W.C. J. Biol. Chem. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar). on the other is but not thrombin-sensitive S. K. C. J. Proc. Natl. Acad. Sci. U. S. A. 1994; PubMed Scopus Google Scholar), is that activation of can in of N. M. M.J. J. Biol. Chem. 2000; Full Text Full Text PDF PubMed Scopus Google Scholar). activation of is to THBS1 expression, a agonist was used to B. K. D. A. S. J. R. J. Biol. Chem. 1996; Full Text Full Text PDF PubMed Scopus Google Scholar, Hung D.T. J. T.K. Wheaton V.I. Coughlin S.R. J. Biol. Chem. 1992; Full Text PDF PubMed Google Scholar). were and via as from with increased THBS1 in at and the effects of thrombin and Thrombin of THBS1 Expression in in and gene expression endothelial cell has been well Immunol. PubMed Scopus Google Scholar, A. J. Fauvel-Lafeve F. Legrand C. Thromb. Haemostasis. 2001; PubMed Scopus Google Scholar, I. S. D. L. T. I. Res. PubMed Scopus (244) Google Scholar, M. D. T. FASEB J. 2003; 17: PubMed Scopus Google Scholar). THBS1 expression is up-regulated by thrombin stimulation in endothelial cell similar were were stimulated with thrombin, and the increase in THBS1 expression was by thrombin stimulated as a Thrombin induced THBS1 expression in to a in These in different endothelial cell that thrombin an increase in THBS1 expression. Thrombin-induced THBS1 Expression the of thrombin to regulate THBS1 expression, the thrombin was as the THBS1 protein expression in The was with an of increase at at the Thrombin-induced THBS1 Expression and have in that to Gi/o, in activation of extracellular kinase A. H. R. T. C. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). activation of is THBS1 expression, were with PTX, and the effects on THBS1 expression were via as with the by The of was by a with These results suggest that activation of is THBS1 of PTX, and Bis I on THBS1 expression. The of THBS1 in was as in cells were with with Bis I stimulation with thrombin. analysis was the a the of cells were with were were to a of in the of as were by and by The is of changes in were in with stimulated with thrombin. the of has been shown to via the H. J. 1996; Google Scholar). is THBS1 expression, were with the with inhibition of was a endothelial is were on and the was in to thrombin. with not the of the but the induced by thrombin, The under conditions These results suggest activation not play a role in THBS1 expression. is to not only and the effects of activation is but as In endothelial activation of an increase in and activation of protein kinase C Thromb. 1992; PubMed Scopus Google Scholar, 67: PubMed Scopus Google Scholar), a kinase that has been shown to the expression of transcription in endothelial cells D. M. J. R. E. N. PubMed Scopus Google Scholar, T. W.C. PubMed Scopus Google Scholar). activation of affects THBS1 expression, were with Bis I stimulation with thrombin. THBS1 was the as of protein kinase C with Bis I in inhibition of THBS1 expression These results suggest that Gq-mediated activation of protein kinase C a of THBS1 Expression by Thrombin in is a glycoprotein of the extracellular THBS1 expression has been linked to pathophysiological states such as atherosclerotic lesions (13Wight T.N. Raugi G.J. Mumby S.M. Bornstein P. J. Histochem. Cytochem. 1985; 33: 295-302Crossref PubMed Scopus (220) Google Scholar), hyperplasia (14Raugi G.J. Mullen J.S. Bark D.H. Okada T. Mayberg M.R. Am. J. Pathol. 1990; 137: 179-185PubMed Google Scholar), hypertension (15Botney M.D. Kaiser L.R. Cooper J.D. Mecham R.P. Parghi D. Roby J. Parks W.C. Am. J. Pathol. 1992; 140: 357-364PubMed Google Scholar), and cancer G.P. Smith M. Rothman V.L. Capuzzi D.M. Joseph R.R. Katz J. Besa E.C. Treat J. Switalska H.I. Thromb. Haemostasis. 1992; 67: 607-611Crossref PubMed Scopus (75) Google Scholar). The mechanism by which THBS1 is up-regulated in disease states, however, is not well understood. THBS1 can from platelet activation via from α-granules, THBS1 is also and by cell of the vascular system including the J. Clin. PubMed Scopus Google Scholar, G.J. Mumby S.M. D. Bornstein P. J. Biol. PubMed Scopus Google Scholar). The effects of thrombin on gene expression and that of THBS1 expression in the well However, THBS1 has been shown to be up-regulated in vasculature cells in to I. Wang K. F. M.S. 2003; PubMed Scopus Google Scholar). on a the effects of thrombin on gene and expression in endothelial a microarray analysis was the only 65 different genes including THBS1 were a of and thrombin and Four expression were into which the genes were THBS1 with a other genes identified in the microarray studies were confirmed by of the 65 gene were up-regulated in to thrombin The microarray not genes expression was microarray studies have been by M. A. PubMed Scopus Google Scholar). In were induced by and of gene in in and However, the genes including THBS1 identified from induced in other endothelial the to cell types. THBS1 was not identified in studies we by that thrombin THBS1 expression in Thrombin of THBS1 Expression in and of THBS1 by correlated with an increase in mRNA and the endothelial cells PAR-1, and the results of the PAR-1-specific peptide of thrombin that activation is to thrombin of THBS1 gene expression with of THBS1 also to be a of the as thrombin induced a increase in THBS1 in from with a in THBS1 protein expression was also shown to be thrombin The from the was is similar to the other other such as of the in J. 1994; PubMed Scopus Google Scholar) and well with the of thrombin K. L. B. Coughlin S.R. J. Biol. Chem. 1993; Full Text PDF PubMed Google Scholar). results suggest that at of thrombin the endothelial cells by THBS1 via a THBS1 that to of THBS1, the promoter region of THBS1 was is a of the predicted promoter of to of the transcription The binding sites the different transcription of the of microarray analysis is the of large from which of can be increase the of a transcription binding in the signaling the promoter of genes that by expression profile were also that the genes of each similar expression is that a of genes under similar The of only transcription binding sites to members of the The transcription were transcription of transcription binding that have been shown to in and were present in of the promoter of the such were identified THBS1. The of of an and binding The predicted of an and which of the predicted transcription was to THBS1 expression, the expression of the members of each transcription family predicted by were the results from the microarray transcription the and to be confirmed transcription from each family MYC and EGR1, respectively, each up-regulated at the of THBS1 expression These results suggest that THBS1 expression may be by the expression of transcription be with the that transcription of the and have in the cell S. R. R. J. L. 2001; PubMed Scopus Google Scholar, J. Cell. PubMed Scopus Google Scholar). In of this THBS1 expression has been linked to MYC C. H. E.L. Dev. PubMed Scopus Google Scholar) and L. D. C. M. S. T. M. 2003; 41: PubMed Scopus Google Scholar, I. M.F. H. 2001; PubMed Google Scholar, T. Bornstein P. J. Biol. Chem. 1994; 269: Full Text PDF PubMed Google Scholar, H. R. M. H. H. Res. PubMed Scopus (75) Google Scholar, V. A. S. S. A. Bornstein P. B. F. PubMed Scopus Google Scholar). In thrombin has been shown to regulate the expression of MYC J. L. T. P. J. 1998; PubMed Scopus Google Scholar, J. 1992; Google Scholar) and T. W.C. PubMed Scopus Google Scholar). promoter of the MYC and genes have of predicted a well of MYC expression Wang J. J. 2004; 10: PubMed Scopus Google Scholar, J. J. Cell. 2004; PubMed Scopus Google Scholar, R. S.M. E. Cell. Biol. 2003; PubMed Scopus Google Scholar, P. S. E. L. F. A. L. Res. 2003; Google Scholar, J. Biol. Chem. 2003; Full Text Full Text PDF PubMed Scopus Google Scholar, S. J.S. Scopus Google Scholar, D.H. J. PubMed Scopus Google Scholar). Analysis also predicted an and transcription family of via activation of extracellular kinase T. W.C. PubMed Scopus Google Scholar, F. V. K. J. J. A. 2004; PubMed Scopus Google Scholar, P. J. Biol. Chem. 2000; Full Text Full Text PDF PubMed Scopus Google Scholar, M. L. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, T. M.J. PubMed Scopus (61) Google Scholar, L. I. A. 1997; PubMed Scopus Google Scholar). have shown that thrombin can extracellular kinase via a in A. H. R. T. C. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). These with present that of cells with THBS1 expression by and a THBS1 expression. that signaling by and to increase THBS1 expression. with that we inhibition of by the inhibition of protein kinase is Gq-mediated by with Bis I also the also that with the and has been by that MYC THBS1 expression in cells and that the is A. Cell. 2003; Full Text Full Text PDF PubMed Scopus Google Scholar). results with the expression of THBS1. suggest that activation of and to well MYC expression is not the of is with the of Rho thrombin stimulation of endothelial cells. In thrombin has been shown to the transcription protein in endothelial cells to expression J. Clin. Investig. 2000; PubMed Scopus Google Scholar, Proc. Natl. Acad. Sci. U. S. A. 2001; PubMed Scopus Google Scholar). was to be in the present microarray studies to the promoter analysis of this other not transcription of an such as THBS1 at the of vascular injury at However, the involved in THBS1 THBS1 transcription is by The of angiogenesis wound healing is is increase in THBS1 be by which the cell the of angiogenesis in to vascular In is that expression of THBS1 in endothelial cells is up-regulated by to thrombin. that THBS1 can at sites of vascular injury from the in addition to platelet the role THBS1 in platelet activation, adhesion of the and the of the which we thrombin of THBS1 important the of THBS1 and may to microarray were in the The is by and and of with