Statins Exert Endothelial Atheroprotective Effects via the KLF2 Transcription Factor

3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, statins, have been shown to positively impact vascular function independent of their plasma lipid-lowering action. Several of these beneficial effects involve modulation of gene expression. Here we explored whether the transcription factor Kruppel-like factor 2 (KLF2), a biomechanically activated gene we recently identified as part of the endothelial “atheroprotective phenotype,” is regulated by statins and whether this mechanism is important for the non-lipid lowering beneficial effects mediated by these drugs in endothelium. The mRNA levels of KLF2 in human umbilical vein endothelial cells increased in the presence of various statins. KLF2 induction was observed within 8 h after drug treatment and remained elevated for at least 24 h. This statin effect on KLF2 expression was reversed by addition of mevalonate and its downstream metabolite geranygeranyl pyrophosphate. Furthermore, inhibition of protein geranylgeranylation with GGTI-298 significantly induced KLF2 levels, whereas inhibition of farnesylation did not. Statin-mediated KLF2 expression was followed by the up-regulation of several of its downstream transcriptional targets. Using small interfering RNA to block KLF2 expression, we demonstrated that this transcription factor is necessary for the statin-mediated regulation of several pathophysiologically relevant genes. These results strongly implicate KLF2 as a transcriptional regulator of the statin-mediated effects in vascular endothelium and provide a novel mechanism for the well established non-lipid lowering beneficial cardiovascular effects of statins. 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, statins, have been shown to positively impact vascular function independent of their plasma lipid-lowering action. Several of these beneficial effects involve modulation of gene expression. Here we explored whether the transcription factor Kruppel-like factor 2 (KLF2), a biomechanically activated gene we recently identified as part of the endothelial “atheroprotective phenotype,” is regulated by statins and whether this mechanism is important for the non-lipid lowering beneficial effects mediated by these drugs in endothelium. The mRNA levels of KLF2 in human umbilical vein endothelial cells increased in the presence of various statins. KLF2 induction was observed within 8 h after drug treatment and remained elevated for at least 24 h. This statin effect on KLF2 expression was reversed by addition of mevalonate and its downstream metabolite geranygeranyl pyrophosphate. Furthermore, inhibition of protein geranylgeranylation with GGTI-298 significantly induced KLF2 levels, whereas inhibition of farnesylation did not. Statin-mediated KLF2 expression was followed by the up-regulation of several of its downstream transcriptional targets. Using small interfering RNA to block KLF2 expression, we demonstrated that this transcription factor is necessary for the statin-mediated regulation of several pathophysiologically relevant genes. These results strongly implicate KLF2 as a transcriptional regulator of the statin-mediated effects in vascular endothelium and provide a novel mechanism for the well established non-lipid lowering beneficial cardiovascular effects of statins. Statins act to reduce plasma cholesterol levels by inhibiting 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) 1The abbreviations used are: HMG-CoA, 3-hydroxy-3-methylglutaryl coenzyme A; LDL, low density lipoprotein; EC, endothelial cells; DPBS, Dulbecco's phosphate-buffered saline; KLF, Kruppel-like factor; HUVEC, human umbilical vein endothelial cells; GGPP, geranygeranyl pyrophosphate; FPP, farnesyl pyrophosphate; siRNA, small interfering RNA; ASS, argininosuccinate synthetase; CNP, C-type natriuretic peptide; PTGDS, prostaglandin D2 synthase; eNOS, endothelial nitricoxide synthase. reductase and currently constitute the most widely prescribed class of drugs for the reduction of morbidity and mortality associated with cardiovascular disease. Interestingly, many of the clinical benefits afforded by these drugs appear to be mechanistically unrelated to their lipid-lowering effects (1Schonbeck U. Libby P. Circulation. 2004; 109: II18-III26Crossref PubMed Google Scholar, 2Liao J.K. Laufs U. Annu. Rev. Pharmacol. Toxicol. 2005; 45: 89-118Crossref PubMed Scopus (1399) Google Scholar). These non-lipid-lowering beneficial effects include improvement in the production of endothelial derived relaxing factor as well as other aspects of endothelial dysfunction (2Liao J.K. Laufs U. Annu. Rev. Pharmacol. Toxicol. 2005; 45: 89-118Crossref PubMed Scopus (1399) Google Scholar, 3Davignon J. Circulation. 2004; 109: III39-III43Crossref PubMed Google Scholar). Indeed, short term statin treatment improves NO-mediated vasodilation and myocardial perfusion before changes in LDL-cholesterol can be detected (4Laufs U. Wassmann S. Hilgers S. Ribaudo N. Bohm M. Nickenig G. Am. J. Cardiol. 2001; 88: 1306-1307Abstract Full Text Full Text PDF PubMed Scopus (183) Google Scholar, 5O'Driscoll G. Green D. Taylor R.R. Circulation. 1997; 95: 1126-1131Crossref PubMed Scopus (944) Google Scholar). Because the clinical benefits in patients on statins occur early in the course of therapy, are seen in patients with LDL-cholesterol levels that are within the normal range, and often appear not to be correlated directly with the degree of LDL-cholesterol reduction, it has been suggested that these benefits may be a result of yet-to-be-defined direct vascular actions, in particular in the endothelium (1Schonbeck U. Libby P. Circulation. 2004; 109: II18-III26Crossref PubMed Google Scholar, 6Ridker P.M. Cannon C.P. Morrow D. Rifai N. Rose L.M. McCabe C.H. Pfeffer M.A. Braunwald E. N. Engl. J. Med. 2005; 352: 20-28Crossref PubMed Scopus (1991) Google Scholar). At the cellular level, statins have been shown to transcriptionally up-regulate eNOS gene expression, stabilize eNOS mRNA, as well as directly influence the activity of the enzyme in endothelium (7Laufs U. La Fata V. Plutzky J. Liao J.K. Circulation. 1998; 97: 1129-1135Crossref PubMed Scopus (1722) Google Scholar). In addition, statins also suppress the expression of the vasoconstrictor endothelin-1 (EDN-1) in endothelial cells (EC) (8Hernandez-Perera O. Perez-Sala D. Navarro-Antolin J. Sanchez-Pascuala R. Hernandez G. Diaz C. Lamas S. J. Clin. Invest. 1998; 101: 2711-2719Crossref PubMed Scopus (749) Google Scholar). Several studies have demonstrated anti-inflammatory effects of these drugs on various cell types implicated in atherosclerosis, including endothelial cells (1Schonbeck U. Libby P. Circulation. 2004; 109: II18-III26Crossref PubMed Google Scholar). These effects include endothelial suppression of adhesion molecule (VCAM-1, E-selectin) and cytokine/chemokine (MCP-1, IL-8, RANTES (regulated on activation normal T cell expressed and secreted)) expression both in vitro and in vivo; additionally, these effects are correlated with reduced macrophage infiltration in early atheroma (9Aikawa M. Rabkin E. Sugiyama S. Voglic S.J. Fukumoto Y. Furukawa Y. Shiomi M. Schoen F.J. Libby P. Circulation. 2001; 103: 276-283Crossref PubMed Scopus (571) Google Scholar, 10Aikawa M. Sugiyama S. Hill C.C. Voglic S.J. Rabkin E. Fukumoto Y. Schoen F.J. Witztum J.L. Libby P. Circulation. 2002; 106: 1390-1396Crossref PubMed Scopus (192) Google Scholar). Statins also have been shown to reduce endothelial thrombogenicity, in part via induction of thrombomodulin expression. Thrombomodulin is an endothelial-specific cell surface molecule that generates activated protein C, a potent inhibitor of the coagulation cascade as well as an anti-inflammatory substance (11Masamura K. Oida K. Kanehara H. Suzuki J. Horie S. Ishii H. Miyamori I. Arterioscler. Thromb. Vasc. Biol. 2003; 23: 512-517Crossref PubMed Scopus (106) Google Scholar). The net beneficial pathophysiological influence of these various non-lipid lowering transcriptional effects of statins on endothelial cells strongly suggests these changes may be a major component of their clinical efficacy. KLF2 is a zinc finger-containing transcription factor implicated in blood vessel development and T lymphocyte activation (12Feinberg M.W. Lin Z. Fisch S. Jain M.K. Trends Cardiovasc. Med. 2004; 14: 241-246Crossref PubMed Scopus (71) Google Scholar, 13Kuo C.T. Veselits M.L. Leiden J.M. Science. 1997; 277: 1986-1990Crossref PubMed Scopus (345) Google Scholar, 14Kuo C.T. Veselits M.L. Barton K.P. Lu M.M. Clendenin C. Leiden J.M. Genes Dev. 1997; 11: 2996-3006Crossref PubMed Scopus (312) Google Scholar). Expression of KLF2 in cultured EC is increased by steady laminar shear stress, a biomechanical stimulus (15Dekker R.J. van Soest S. Fontijn R.D. Salamanca S. de Groot P.G. VanBavel E. Pannekoek H. Horrevoets A.J. Blood. 2002; 100: 1689-1698Crossref PubMed Scopus (543) Google Scholar, 16SenBanerjee S. Lin Z. Atkins G.B. Greif D.M. Rao R.M. Kumar A. Feinberg M.W. Chen Z. Simon D.I. Luscinskas F.W. Michel T.M. Gimbrone Jr., M.A. Garcia-Cardena G. Jain M.K. J. Exp. Med. 2004; 199: 1305-1315Crossref PubMed Scopus (551) Google Scholar). Moreover, we have demonstrated induction of KLF2 in cultured human EC in response to the complex hemodynamic environment found in regions of the carotid bifurcation that are resistant to the development of atherosclerosis, thus suggesting that this transcription factor may exert an “atheroprotective” function (15Dekker R.J. van Soest S. Fontijn R.D. Salamanca S. de Groot P.G. VanBavel E. Pannekoek H. Horrevoets A.J. Blood. 2002; 100: 1689-1698Crossref PubMed Scopus (543) Google Scholar, 17Dai G. Kaazempur-Mofrad M.R. Natarajan S. Zhang Y. Vaughn S. Blackman B.R. Kamm R.D. Garcia-Cardena G. Gimbrone Jr., M.A. Proc. Natl. Acad. Sci. U. S. A. 2004; 101: 14871-14876Crossref PubMed Scopus (526) Google Scholar). Interestingly, using in situ hybridization, Dekker et al. (15Dekker R.J. van Soest S. Fontijn R.D. Salamanca S. de Groot P.G. VanBavel E. Pannekoek H. Horrevoets A.J. Blood. 2002; 100: 1689-1698Crossref PubMed Scopus (543) Google Scholar) have shown a relative lack of KLF2 expression in the endothelial lining at bifurcations in the human aorta, a region where early lesions of atherosclerosis are prone to develop. Recent work in our laboratory indicates this transcription factor regulates multiple endothelial functions by acting as an integrator of hemodynamic and humoral stimuli. 2K. Parmar, Y. Zhang, G. Dai, J. R. Kratz, S. Natarajan, E. T. Wang, H. B. Larman, Z. Lin, M. Jain, M. A. Gimbrone, and G. García-Cardena, submitted for publication. KLF2 overexpression inhibits the proinflammatory and prothrombotic endothelial gene expression observed in the face of proinflammatory stimuli (16SenBanerjee S. Lin Z. Atkins G.B. Greif D.M. Rao R.M. Kumar A. Feinberg M.W. Chen Z. Simon D.I. Luscinskas F.W. Michel T.M. Gimbrone Jr., M.A. Garcia-Cardena G. Jain M.K. J. Exp. Med. 2004; 199: 1305-1315Crossref PubMed Scopus (551) Google Scholar, 18Lin Z. Kumar A. Senbanerjee S. Staniszewski K. Parmar K. Vaughan D.E. Gimbrone Jr., M.A. Balasubramanian V. Garcia-Cardena G. Jain M.K. Circ. Res. 2005; 96: e48-e57Crossref PubMed Google Scholar). Because the KLF2-dependent transcriptional and functional effects observed in endothelial cells exposed to atheroprotective flow were reminiscent of the previously reported statin-mediated changes in endothelial gene expression, we directly examined whether KLF2 and its transcriptional targets are regulated directly by statins. Cell Culture—Human umbilical vein endothelial cells (HUVEC) were plated at densities of 60,000 cells/cm2 in 6-well plates (Costar) in medium 199 (BioWhittaker) supplemented with 50 μg/ml endothelial cell growth supplement (Collaborative Research), 100 μg/ml heparin (Sigma), 100 units/ml penicillin-G + 100 μg/ml streptomycin (BioWhittaker), 2 mm l-Gln (Invitrogen), and 20% fetal bovine serum (BioWhittaker). Cells were allowed to grow to confluence for 24 h while incubated under 37 °C and 5% CO2 conditions. RNA Isolation and Quantitative Real-time Taqman PCR—RNA isolation, cDNA preparation, and real-time Taqman PCR were performed essentially as described previously (17Dai G. Kaazempur-Mofrad M.R. Natarajan S. Zhang Y. Vaughn S. Blackman B.R. Kamm R.D. Garcia-Cardena G. Gimbrone Jr., M.A. Proc. Natl. Acad. Sci. U. S. A. 2004; 101: 14871-14876Crossref PubMed Scopus (526) Google Scholar). Briefly, RNA was ethanol-precipitated from the TRIzol lysates, and integrity was assessed using the RNA 6000 Nano-Assay using a microfluidics Quantitative was performed on a Expression of was used as an in and as described 2 of were with statins at of 100 was a from K. and R. and were from and in medium was also as was medium with of to as a for the and Cells were incubated for 24 h under 37 °C and 5% CO2 with DPBS, and in of TRIzol the cells were cultured in with 100 and cells were incubated for 24 h. Cells were with and in of the course were plated as before addition of 100 of in Cells were incubated for 24 h. At the cells were with and in of and were cultured in the presence of 100 with of geranygeranyl farnesyl for 24 h 8 h before RNA and of and was reported by the to be by for the used in these was used as GGTI-298 and were in and the also used the of in Cells were cultured with the of for 8 h before TRIzol were were with KLF2 by The and of human KLF2 and and and were and were plated h to at a density of cells/cm2 in growth medium At the of with siRNA, the cells were a and siRNA, were with and in a of and incubated at for for the complex to Cells were and of was of the complex was to the The cells were incubated for h at 37 growth medium was and cells were incubated for an h. Statins were as described and RNA was 24 h whether KLF2 may a in the transcriptional expression of multiple endothelial by statins, we whether statins the expression levels of of cultured with and of statins for h a up-regulation of KLF2 for of with the of Interestingly, effect on KLF2 expression at of the is with other studies transcriptional changes in response to this statin (11Masamura K. Oida K. Kanehara H. Suzuki J. Horie S. Ishii H. Miyamori I. Arterioscler. Thromb. Vasc. Biol. 2003; 23: 512-517Crossref PubMed Scopus (106) Google Scholar). the up-regulation of KLF2 in to be a class effect of statins. The course of KLF2 induction by was assessed by KLF2 levels in at with the drug at a of 100 The of KLF2 was observed at and it at 8 h. KLF2 levels remained elevated 8 h with the induction was at the These that KLF2 levels at 8 h in response to treatment and elevated to at least 24 suggesting the in KLF2 expression is not a inhibiting the activity of statins cells of this metabolite of the and its downstream whether the KLF2 up-regulation is on inhibition of we whether mevalonate to the cells the effect of Cells were incubated with and with a of of for 24 h. the effect on KLF2 expression was not increased KLF2 levels as shown and this induction was with of mevalonate in the thus the effects of on KLF2 expression in a these changes are on inhibition of the downstream and These to important to cell and their activity whether of these of the mevalonate was important for the observed statin-mediated effects on KLF2 expression, was to the medium of with for 8 h. of with effect on KLF2 expression of significantly reduced KLF2 up-regulation in the presence of treatment with was to the KLF2 This suggests that statins up-regulate KLF2 levels in by from endothelial the of cellular in KLF2 regulation by statins, we of an inhibitor of farnesyl the that to of with the in a up-regulation of KLF2 of farnesyl with was not to this effect at The induction by GGTI-298 of KLF2 expression was with that with that GGTI-298 the statin-mediated effect on KLF2 expression. a novel in vitro that shear in in and regions of the human carotid we demonstrated that EC exposed to these types of biomechanical stimuli of gene expression and functional (17Dai G. Kaazempur-Mofrad M.R. Natarajan S. Zhang Y. Vaughn S. Blackman B.R. Kamm R.D. Garcia-Cardena G. Gimbrone Jr., M.A. Proc. Natl. Acad. Sci. U. S. A. 2004; 101: 14871-14876Crossref PubMed Scopus (526) Google Scholar). EC exposed to the shear in expressed of anti-inflammatory and endothelial have also recently demonstrated that the expression of the transcription factor KLF2 and several of its transcriptional targets are induced by the atheroprotective and that the KLF2 expression an atheroprotective endothelial statins also their major transcriptional targets by KLF2 expression, we that KLF2 induction by statins the statin-mediated regulation of its downstream transcriptional targets. Because we found KLF2 up-regulation to appear at h and by 8 we the expression of important established and novel KLF2 targets after 8 and 24 h of with 100 of the most regulated transcriptional targets of KLF2 are argininosuccinate C-type natriuretic and prostaglandin D2 is a factor for eNOS while is an endothelial that also functions in as of its the most potent of has well anti-inflammatory activity V. Circulation. 101: PubMed Scopus Google Scholar). for the targets a up-regulation of by the treatment at the 8 and 24 h and at the 24 h for the of the targets Because KLF2 induction is at it is that these targets are regulated at a with a of KLF2 in their transcriptional response to the of KLF2 up-regulation in statin-mediated effects in endothelial we the induction of KLF2 using treatment of endothelial cells with KLF2 in KLF2 levels to the functional under these we the expression of various transcriptional targets previously identified as to statins S. C. Y. A. Y. T. T. J. Thromb. 2004; 11: PubMed Scopus Google Scholar). the to be regulated by statins, we found that the up-regulation of eNOS, and by was up-regulation of KLF2 was of has been as an important anti-inflammatory effect of the statins, also was KLF2 up-regulation was also whether the novel transcriptional targets we have identified as were to of these targets CNP, were regulated by of KLF2 up-regulation their induction by the of KLF2 thus to be for multiple pathophysiologically relevant changes in endothelial gene expression induced by is that the clinical benefits from the of statins may from their effects on and cell types in reduction of plasma cholesterol levels (1Schonbeck U. Libby P. Circulation. 2004; 109: II18-III26Crossref PubMed Google Scholar). of is the direct vascular effects of statins, on the endothelium (2Liao J.K. Laufs U. Annu. Rev. Pharmacol. Toxicol. 2005; 45: 89-118Crossref PubMed Scopus (1399) Google Scholar). important direct effects of these drugs on the vascular endothelium are and not a result of transcriptional regulation of eNOS and Y. Z. I. A. D. K. Med. PubMed Scopus Google Scholar, M.A. C. J.M. Am. J. 2004; PubMed Scopus Google many studies that important transcriptional changes occur in endothelial cells exposed to statins, changes that act to a atheroprotective effect (11Masamura K. Oida K. Kanehara H. Suzuki J. Horie S. Ishii H. Miyamori I. Arterioscler. Thromb. Vasc. Biol. 2003; 23: 512-517Crossref PubMed Scopus (106) Google Scholar, J. M. J. O. Arterioscler. Thromb. Vasc. Biol. 2003; 23: PubMed Scopus Google Scholar, T. Libby P. Arterioscler. Thromb. Vasc. Biol. PubMed Scopus Google Scholar). Here we KLF2 as a transcriptional of statins and its in endothelial transcriptional statins were shown to endothelial KLF2 expression at in patients A. Exp. Clin. Pharmacol. 2003; PubMed Scopus Google Scholar, E. J. R. A. C. Am. J. Cardiol. Full Text Full Text PDF PubMed Scopus Google Scholar). effect at the to its relative its endothelial cells by (2Liao J.K. Laufs U. Annu. Rev. Pharmacol. Toxicol. 2005; 45: 89-118Crossref PubMed Scopus (1399) Google Scholar). that the least in KLF2 also this drug in other studies using several cultured cell including endothelial cells (11Masamura K. Oida K. Kanehara H. Suzuki J. Horie S. Ishii H. Miyamori I. Arterioscler. Thromb. Vasc. Biol. 2003; 23: 512-517Crossref PubMed Scopus (106) Google Scholar). The course of KLF2 up-regulation is and the regulation of the other statin targets with an of KLF2 on these transcriptional targets. these statin-mediated effects are reversed by addition of that the effect is on inhibition of The downstream of mevalonate include that are for of major as and for and J.K. J. Clin. Invest. 2002; PubMed Scopus Google Scholar). found that addition of GGPP, not FPP, the effects of statins on KLF2 expression, the observed changes are mediated by cells of Because is to and this result also suggests that of these our observed induction of the we observed for in the up-regulation of KLF2 may a of the we observed that the induction of KLF2 was with a inhibitor in a not with a farnesyl our thus to statins endothelial KLF2 via of in these GGPP, not FPP, is for the activity of many of the for the in KLF2 expression a that suppression of KLF2 under at the transcriptional via of statins in this the activity of this thus KLF2 to be expressed thus be of to the in effects on atherosclerosis by have effect on the while KLF2 in endothelial cells and other cell statins are to these drugs most other cell types in in addition to endothelial including KLF2 expression has been demonstrated in and its to a activated in T cells C.T. Veselits M.L. Leiden J.M. Science. 1997; 277: 1986-1990Crossref PubMed Scopus (345) Google Scholar). the of KLF2 for endothelial gene expression in response to statins, and the demonstrated effects of statins on lymphocyte it be to whether an for KLF2 in to the currently of statins in the of L.M. B. J.L. C. Diaz C. Hernandez G. J. Circulation. 2003; PubMed Scopus Google Scholar). have identified CNP, an endothelial and anti-inflammatory that on cells H. A. A.J. Proc. Natl. Acad. Sci. U. S. A. 2003; 100: PubMed Scopus Google Scholar, A. Y. T. Y. T. H. Circ. Res. 2002; PubMed Scopus Google as a induced of KLF2 and statins in endothelial for changes in the cardiovascular in various cell types and are P.M. Vaughan D.E. J.L. Circulation. 2004; 109: PubMed Google Scholar). has been on serum that as an of and a with the morbidity and mortality associated with P.M. Rifai N. Rose N. Engl. J. Med. 2002; PubMed Scopus Google Scholar, P.M. C.H. Rifai N. N. Engl. J. Med. PubMed Scopus Google Scholar, M.A. R.J. P.M. Circulation. 2003; PubMed Scopus Google Scholar). it be to that can act as direct of endothelial clinical suggests that the of atherosclerosis and its may be in endothelial 2003; PubMed Scopus Google Scholar, J. P. Circulation. 2004; 109: PubMed Google Scholar). dysfunction has been by to G. J. Pharmacol. 2002; PubMed Scopus Google Scholar, R.R. P. N. Engl. J. Med. PubMed Scopus Google Scholar). of endothelial function be to the in endothelial function and the effects of statins on this important is an endothelial factor that has been implicated in vasodilation in vascular in addition to effects on H. A. A.J. Proc. Natl. Acad. Sci. U. S. A. 2003; 100: PubMed Scopus Google Scholar, N. H. T. K. K. K. J. M. K. N. Y. S. M. T. H. M. K. Circulation. 2002; PubMed Scopus Google Scholar). in a on vascular cells by on the that is also to A. A.J. Pharmacol. 2005; PubMed Scopus Google Scholar). that is induced by statins in a KLF2-dependent this molecule as a of endothelial function and a of the vascular effects of statin The expression of KLF2 was shown to be in cultured endothelial cells by steady laminar shear and to be expressed in of human (15Dekker R.J. van Soest S. Fontijn R.D. Salamanca S. de Groot P.G. VanBavel E. Pannekoek H. Horrevoets A.J. Blood. 2002; 100: 1689-1698Crossref PubMed Scopus (543) Google Scholar). Interestingly, we demonstrated that KLF2 expression is in cultured endothelial cells exposed to an atheroprotective shear as with the to (17Dai G. Kaazempur-Mofrad M.R. Natarajan S. Zhang Y. Vaughn S. Blackman B.R. Kamm R.D. Garcia-Cardena G. Gimbrone Jr., M.A. Proc. Natl. Acad. Sci. U. S. A. 2004; 101: 14871-14876Crossref PubMed Scopus (526) Google Scholar). Recent work in our laboratory has KLF2 as a regulator of multiple endothelial functions including not to blood vessel of vascular and Moreover, induced of KLF2 expression in endothelial cells exposed to atheroprotective shear to the suppression of atheroprotective gene expression and the atheroprotective In addition, overexpression have demonstrated a for KLF2 in the of an anti-inflammatory and endothelial (16SenBanerjee S. Lin Z. Atkins G.B. Greif D.M. Rao R.M. Kumar A. Feinberg M.W. Chen Z. Simon D.I. Luscinskas F.W. Michel T.M. Gimbrone Jr., M.A. Garcia-Cardena G. Jain M.K. J. Exp. Med. 2004; 199: 1305-1315Crossref PubMed Scopus (551) Google Scholar, 18Lin Z. Kumar A. Senbanerjee S. Staniszewski K. Parmar K. Vaughan D.E. Gimbrone Jr., M.A. Balasubramanian V. Garcia-Cardena G. Jain M.K. Circ. Res. 2005; 96: e48-e57Crossref PubMed Google Scholar). The of KLF2 as a major of statins, of the most widely used class of drugs for cardiovascular the that statins a atheroprotective endothelial that is on KLF2 Indeed, recently performed in our laboratory have shown that statins are to the observed in endothelial cells exposed to a of regions of the human carotid the atheroprotective as assessed by of transcriptional B. and G. we demonstrated that KLF2 is both necessary and to many of the endothelial atheroprotective transcriptional to for statins. the of KLF2 in endothelial and its to the beneficial effects of statins on the vascular drugs to endothelial KLF2 expression, its downstream result in novel vascular in various in endothelial dysfunction a and for and of endothelial cells and Chen for of the