Characterisation of multi-layered structures using a vector-based gradient descent algorithm at terahertz frequencies.

Material characterisation and imaging applications using terahertz radiation have gained interest in the past few years due to their enormous potential for industrial applications. The availability of fast terahertz spectrometers or multi-pixel terahertz cameras has accelerated research in this domain. In this work, we present a novel vector-based implementation of the gradient descent algorithm to fit the measured transmission and reflection coefficients of multilayered objects to a scattering parameter-based model, without requiring any analytical formulation of the error function. We thereby extract thicknesses and refractive indices of the layers within a maximum 2% error margin. Using the precise thickness estimates, we further image a 50 nm-thick Siemens star deposited on a silicon substrate using wavelengths larger than 300 µm. The vector-based algorithm heuristically finds the error minimum where the optimisation problem cannot be analytically formulated, which can be utilised also for applications outside the terahertz domain.

Murine sca1/flk1-positive cells are not endothelial progenitor cells, but B2 lymphocytes.

Circulating sca1+/flk1+ cells are hypothesized to be endothelial progenitor cells (EPCs) in mice that contribute to atheroprotection by replacing dysfunctional endothelial cells. Decreased numbers of circulating sca1+/flk1+ cells correlate with increased atherosclerotic lesions and impaired reendothelialization upon electric injury of the common carotid artery. However, legitimate doubts remain about the identity of the putative EPCs and their contribution to endothelial restoration. Hence, our study aimed to establish a phenotype for sca1+/flk1+ cells to gain a better understanding of their role in atherosclerotic disease. In wild-type mice, sca1+/flk1+ cells were mobilized into the peripheral circulation by granulocyte-colony stimulating factor (G-CSF) treatment and this movement correlated with improved endothelial regeneration upon carotid artery injury. Multicolor flow cytometry analysis revealed that sca1+/flk1+ cells predominantly co-expressed surface markers of conventional B cells (B2 cells). In RAG2-deficient mice and upon B2 cell depletion, sca1+/flk1+ cells were fully depleted. In the absence of monocytes, sca1+/flk1+ cell levels were unchanged. A PCR array focused on cell surface markers and next-generation sequencing (NGS) of purified sca1+/flk1+ cells confirmed their phenotype to be predominantly that of B cells. Finally, the depletion of B2 cells, including sca1+/flk1+ cells, in G-CSF-treated wild-type mice partly abolished the endothelial regenerating effect of G-CSF, indicating an atheroprotective role for sca1+/flk1+ B2 cells. In summary, we characterized sca1+/flk1+ cells as a subset of predominantly B2 cells, which are apparently involved in endothelial regeneration.

Inhibition of four-and-a-half LIM domain protein-2 increases survival, migratory capacity, and paracrine function of human early outgrowth cells through activation of the sphingosine kinase-1 pathway: implications for endothelial regeneration.

RATIONALE: Inhibition of four-and-a-half LIM domain protein-2 (FHL2) attenuates atherosclerotic lesion formation and increases endothelial cell migration. Early outgrowth cells (EOCs) contribute substantially to endothelial repair. OBJECTIVE: We investigated the role of FHL2 in the regulation of EOCs. METHODS AND RESULTS: Human EOCs were cultured from peripheral blood. FHL2 knockdown in EOCs by siRNA resulted in increased EOC numbers and reduced apoptosis, as indicated by decreased cleaved caspase-III and reduced Bax/Bcl-2 expression ratio. This was mediated through increased phosphorylation and membrane translocation of sphingosine kinase-1, increased sphingosine-1-phosphate levels, and Akt phosphorylation. FHL2 knockdown increased stromal cell-derived factor-1-induced EOC migration through upregulation of αv/ß3, αv/ß5, and ß2 integrins, associated with increased cortactin expression. Reduced apoptosis, increased EOC migration, and cortactin upregulation by FHL2 siRNA were prevented by CAY10621, the sphingosine kinase-1 inhibitor, and the sphingosine-1-phosphate receptor-1/-3 antagonist VPC23019. These findings were confirmed using spleen-derived EOCs from FHL2(-/-) mice. Apoptosis was decreased and migration increased in endothelial cells exposed to the conditioned medium of FHL2(-/-) versus wild-type (WT) EOCs. These paracrine effects were abolished by VPC23019. Importantly, reendothelialization after focal carotid endothelial injury in WT mice was significantly increased after intravenous injection of FHL2(-/-) versus WT EOCs. CONCLUSIONS: Our findings suggest that FHL2 negatively regulates EOC survival, migration, and paracrine function. FHL2 inhibition in EOCs reduces apoptosis and enhances survival and migratory capacity of both EOCs and surrounding endothelial cells by activation of the sphingosine kinase-1/sphingosine-1-phosphate pathway, resulting in improvement of endothelial regeneration.

Absence of Four-and-a-Half LIM Domain Protein 2 Decreases Atherosclerosis in ApoE-/- Mice.

OBJECTIVE: Four-and-a-half LIM domain protein-2 (FHL2) is expressed in endothelial cells, vascular smooth muscle cells, and leukocytes. It regulates cell survival, migration, and inflammatory response, but its role in atherogenesis is unknown. APPROACH AND RESULTS: To investigate the role of FHL2 in atherosclerosis, FHL2-deficient mice were crossed with ApoE-deficient mice, to generate ApoE/FHL2-/- mice. After high-fat diet, ApoE/FHL2-/- mice had significantly smaller atherosclerotic plaques than ApoE-/- mice in the aortic sinus, the brachiocephalic artery, and the aorta. This was associated with enhanced collagen and smooth muscle cell contents and a 2-fold reduction in macrophage content within the plaques of ApoE/FHL-2-/- versus ApoE-/- mice. This could be explained, in part, by the reduction in aortic ICAM-1 (intracellular adhesion molecule) mRNA and VCAM-1 (vascular cell adhesion molecule) protein expression in the plaque. Aortic gene expression of the chemokines CX3CL1 and CCL5 was increased in ApoE/FHL2-/- versus ApoE-/- mice. Peritoneal thioglycollate injection elicited equivalent numbers of monocytes and macrophages in both groups, but a significantly lower number of proinflammatory Ly6C high monocytes were recruited in ApoE/FHL2-/- versus ApoE-/- mice. Furthermore, mRNA levels of CX3CR1 were 2-fold higher in monocytes from ApoE/FHL2-/- versus ApoE-/- mice. Finally, we investigated the potential importance of myeloid cell FHL2 deficiency in atherosclerosis. After being irradiated, ApoE-/- or ApoE/FHL2-/- mice were transplanted with ApoE-/- or ApoE/FHL2-/- bone marrow. After high-fat diet, both chimeric groups developed smaller plaques than ApoE-/- transplanted with ApoE-/- bone marrow. CONCLUSIONS: These results suggest that FHL2 in both myeloid and vascular cells may play an important role in atherosclerosis by promoting proinflammatory chemokine production, adhesion molecule expression, and proinflammatory monocyte recruitment.

Oral anticoagulation in patients with left ventricular thrombus - a systematic review and meta-analysis.

AIMS: Direct oral anticoagulants (DOACs) are increasingly used off-label to treat patients with left ventricular thrombus (LVT). We analyzed available meta-data comparing DOACs and vitamin K antagonists (VKAs) for efficacy and safety. METHODS: We conducted a systematic search and meta-analysis of observational and randomized data comparing DOACs versus VKAs in patients with LVT. Endpoints of interest were stroke or systemic embolism, thrombus resolution, all-cause death, and a composite bleeding endpoint. Estimates were pooled using a random-effect model meta-analysis, and their robustness was investigated using sensitivity and influential analyses. RESULTS: We identified 22 articles (18 observational studies, 4 small randomized clinical trials) reporting on a total of 3,587 patients (2,489 VKA vs. 1,098 DOAC therapy). The pooled estimates for stroke or systemic embolism (OR 0.81; 95% CI [0.57, 1.15]) and thrombus resolution (OR 1.12; 95% CI [0.86; 1.46]) were comparable, and there was low heterogeneity overall across the included studies. DOAC use was associated with lower odds of all-cause death (OR 0.65; 95%CI [0.46; 0.92]) and a composite bleeding endpoint (OR 0.67; 95%CI [0.47; 0.97]). A risk of bias was evident particularly for observational reports, with some publication bias suggested in funnel plots. CONCLUSION: In this comprehensive analysis of mainly observational data, the use of DOACs was not associated with a significant difference in stroke or systemic embolism, or thrombus resolution compared to VKA therapy. The use of DOACs was associated with a lower rate of all-cause death and fewer bleeding events. Adequately sized randomized clinical trials are needed to confirm these findings, which could allow a wider adoption of DOACs in patients with LVT.

AT1-receptor-deficiency induced atheroprotection in diabetic mice is partially mediated via PPARγ.

OBJECTIVE: Peroxisome-proliferator-activated-receptor-γ (PPARγ) acts as a transcriptional regulator of multiple genes involved in glucose and lipid metabolism. In vitro studies showed that activated PPARγ suppresses AT1R-gene expression and vice versa. However, it has not yet been determined in vivo, whether AT1R-PPARγ-interactions play a relevant role in the pathogenesis of diabetic complications and specifically in accelerated atherosclerosis. METHODS AND RESULTS: ApoE-/- and ApoE-/-/AT1R-/--mice were rendered diabetic by intraperitoneal injections of streptozotocin. Diabetic and non-diabetic ApoE-/--mice were further randomized to receive the AT1R antagonist telmisartan, the selective PPARγ antagonist GW9662, telmisartan and GW9662 or vehicle for 18 weeks. Diabetic and non-diabetic ApoE-/-/AT1R-/--mice were randomized to receive either GW9662 or vehicle. GW9662 treatment in diabetic ApoE-/- and diabetic ApoE-/-/AT1-/--mice resulted in the highest elevation of fasting blood glucose levels, whereas telmisartan treatment and AT1 deficiency in ApoE-/--mice showed the lowest fasting blood glucose levels. Diabetic ApoE-/--mice displayed severe impairment of endothelial function, enhanced oxidative stress and increased atherosclerotic lesion formation. ApoE-/-/AT1R-/- and telmisartan-treated ApoE-/--mice showed a significantly better endothelial function, decreased oxidative stress and reduced atherosclerotic lesion formation. Treatment of diabetic ApoE-/- and ApoE-/-/AT1R-/--mice with the selective PPARγ antagonist GW9662 omitted the atheroprotective effects of AT1R deficiency or AT1 antagonism. CONCLUSION: Genetic disruption or pharmacological inhibition of the AT1R attenuates atherosclerosis and improves endothelial function in diabetic ApoE-/--mice via the PPARγ pathway.

Activation of endothelial toll-like receptor 3 impairs endothelial function.

RATIONALE: Endothelial dysfunction and atherosclerosis are chronic inflammatory diseases characterized by activation of the innate and acquired immune system. Specialized protein receptors of the innate immune system recognize products of microorganisms and endogenous ligands such as nucleic acids. Toll-like receptor 3 (TLR3), for example, detects long double-stranded RNA and is abundantly expressed in endothelial cells. Whether innate immunity contributes to atherogenic mechanisms in endothelial cells is poorly understood. OBJECTIVE: We sought to determine the effects of TLR3 activation in endothelial cells. METHODS AND RESULTS: We first investigated whether stimulation of TLR3 influences endothelial biology in mice. Intravenous injection of polyinosine polycytidylic acid, a synthetic double-stranded RNA analog and TLR3 ligand, impaired endothelium-dependent vasodilation, increased vascular production of reactive oxygen species, and reduced reendothelialization after carotid artery injury in wild-type mice compared with controls but had no effect in TLR3(-/-) animals. TLR3 stimulation not only induced endothelial dysfunction but also enhanced the formation of atherosclerotic plaques in apolipoprotein E-deficient mice. In vitro incubation of endothelial cells with polyinosine polycytidylic acid induced production of the proinflammatory cytokines interleukin-8 and interferon-γ-induced protein 10, increased formation of reactive oxygen species, diminished proliferation, and increased apoptosis, which suggests that endothelial cells are able to directly detect and respond to TLR3 ligands. Neutralization of interleukin-8 and interferon-γ-induced protein 10 antagonizes the observed negative effects of polyinosine polycytidylic acid. We found elevated levels of circulating endothelial progenitor cells in polyinosine polycytidylic acid-treated mice, although they displayed increased endothelial dysfunction. Stimulation of TLR3 in cultured endothelial progenitor cells, however, led to increased formation of reactive oxygen species, increased apoptosis, and reduced migration. Injection of endothelial progenitor cells that had been incubated with polyinosine polycytidylic acid ex vivo hindered reendothelialization after carotid artery injury. Therefore, endothelial progenitor cell function was affected by TLR3 stimulation. Finally, apolipoprotein E-deficient/TLR3-deficient mice exhibited improved endothelial function compared with apolipoprotein E-deficient/TLR3(+/+) littermates. CONCLUSIONS: Immunorecognition of long double-stranded RNA by endothelial cells may be an important mechanism involved in endothelial cell activation and development of endothelial dysfunction.

Improved Persistence to Medication, Decreased Cardiovascular Events and Reduced All-Cause Mortality in Hypertensive Patients With Use of Single-Pill Combinations: Results From the START-Study.

BACKGROUND: Single-pill combination improves adherence and persistence to medication in hypertension. It remains unclear whether this also reduces cardiovascular outcomes and all-cause mortality. We analyzed whether single-pill combinations are superior to identical multiple pills on persistence to medication, cardiovascular outcomes, and all-cause mortality. METHODS: This was a retrospective claims data (German AOK PLUS) analysis. Data from hypertensive patients ≥18 years treated with renin-angiotensin system combinations given as single pill or identical multipills covering the years 2012 to 2018 were analyzed and followed up to at least 1 year. After 1:1 propensity score matching, persistence to medication, cardiovascular events, and all-cause mortality were compared using non-parametric tests. Results were reported as incidence rate ratios and hazard ratios. RESULTS: After propensity score matching data from 57 998 patients were analyzed: 10 801 patients received valsartan/amlodipine, 1026 candesartan/amlodipine, 15 349 ramipril/amlodipine, and 1823 amlodipine/valsartan/hydrochlorothiazide as single pill or identical multipill. No relevant differences in patient characteristics were observed within the 4 groups. In all groups, a significant lower all-cause mortality, a significant a higher persistence to medication, a significant lower event rate in 15 out of 20 comparisons, and a tendency in the remaining 5 comparisons was observed under single pills compared with multipill combinations. CONCLUSIONS: Antihypertensive combination therapy reduces all-cause mortality and cardiovascular events when provided as single pill compared to identical drugs as multipills. This strongly supports the European Society of Cardiology/European Society of Hypertension and International Society of Hypertension guidelines recommending the use of a single-pill combination and thus should be more rigorously implemented into daily clinical practice.

Stimulation of the AT2 receptor reduced atherogenesis in ApoE(-/-)/AT1A(-/-) double knock out mice.

AT1 receptor blockers (ARB) and in part ACE inhibitors (ACI) potentially exert beneficial effects on atherogenesis independent of AT1 receptor inhibition. These pleiotropic effects might be related to angiotensin II mediated activation of the AT2 receptor. To analyze this hypothesis we investigated the development of atherosclerosis and the role of ACIs and ARBs in apolipoprotein E-deficient (ApoE(-/-)) mice and in ApoE/AT1A receptor double knockout mice (ApoE(-/-)/AT1A(-/-)). ApoE(-/-) mice and ApoE(-/-)/AT1A(-/-) mice were fed cholesterol-rich diet for 7 weeks. Vascular oxidative stress, endothelial dysfunction, and atherosclerotic lesion formation were evident in ApoE(-/-) mice, but were markedly reduced in ApoE(-/-)/AT1A(-/-) mice. Concomitant treatment of ApoE(-/-)/AT1A(-/-) mice with either telmisartan or ramipril had no additional effect on blood pressure, vascular oxidative stress, AT2 receptor expression, and endothelial function. Remarkably, atherosclerotic lesion formation was increased in ramipril treated ApoE(-/-)/AT1A(-/-) mice compared to untreated ApoE(-/-)/AT1A(-/-) mice whereas pharmacological AT1 receptor inhibition with telmisartan had no additional effect on atherogenesis. Moreover, chronic AT2 receptor inhibition with PD123,319 significantly increased plaque development in ApoE(-/-)/AT1A(-/-) mice. In additional experiments, direct AT2 receptor stimulation reduced atherogenesis in ApoE(-/-)/AT1A(-/-) mice. Taken together, our data demonstrate a relevant antiatherosclerotic role of the AT2 receptor in atherosclerotic mice and provide novel insight in RAS-physiology.

Effects of Single Pill Combinations Compared to Identical Multi Pill Therapy on Outcomes in Hypertension, Dyslipidemia and Secondary Cardiovascular Prevention: The START-Study.

AIM: Current guidelines for the treatment of arterial hypertension (AH) or cardiovascular (CV) prevention recommend combination drug treatments with single pill combinations (SPC) to improve adherence to treatment. We aimed to assess whether the SPC concept is clinically superior to multi pill combination (MPC) with identical drugs. METHODS AND RESULTS: In an explorative study, we analyzed anonymized claims data sets of patients treated with CV drugs for hypertension and/or CV disorders who were insured by the German AOK PLUS statutory health fund covering 01/07/2012-30/06/2018. Patients at age ≥18 years who received either a SPC or MPC with identical drugs were followed for up to one year. A one to one propensity score matching (PSM) was applied within patient groups who started identical drug combinations, and results were reported as incidence rate ratios (IRRs) as well as hazard ratios (HRs). After PSM, data from 59,336 patients were analyzed. In 30 out of 56 IRR analyses, superiority of SPC over MPC was shown. In 5 out of 7 comparisons, the HR for the composite outcome of all-cause death and all-cause hospitalizations was in favor of the SPC regimen (SPC versus MPC): valsartan/amlodipine: HR=0.87 (95% CI: 0.84-0.91, p ≤ 0.001); candesartan/amlodipine: 0.77 (95% CI: 0.65-0.90, p = 0.001); valsartan/amlodipine/hydrochlorothiazide: HR=0.68 (95% CI: 0.61-0.74, p ≤ 0.001); ramipril/amlodipine: HR=0.80 (95% CI: 0.77-0.83, p ≤ 0.001); acetylsalicylic acid (ASA)/atorvastatin/ramipril: HR=0.64 (95% CI: 0.47-0.88, p = 0.005). CONCLUSION: SPC regimens are associated with a lower incidence of CV events and lower all-cause mortality in clinical practice. SPC regimens should generally be preferred to improve patient's prognosis.

Effects of cardiovascular single pill combinations compared with identical multi-pill therapies on healthcare cost and utilization in Germany.

Aim: This study assessed whether a single pill combination (SPC) is associated with lower direct healthcare costs. Materials & methods: Anonymized claims data of patients ≥18 years treated with drugs for cardiovascular (CV)-related diseases either as a single pill combination or multi-pill combination (follow-up to 1 year) were evaluated. After propensity score matching, 59,336 out of 1,369,840 patients were analyzed. Results: In all cohorts, patients receiving a single pill combination had a lower frequency of general practitioner and specialist visits. The patients also had a significantly lower ratio of all-cause hospitalization days and number of CV-related prescriptions as well as all-cause prescriptions (with one exception) compared with those receiving a multi-pill combination. Conclusion: Direct CV-related costs were significantly lower in four out of seven comparisons, with a trend toward lower costs in the other three comparisons.

Facing the challenge of polypharmacy when prescribing for older people with cardiovascular disease. A review by the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy.

Population ageing has resulted in an increasing number of older people living with chronic diseases (multimorbidity) requiring five or more medications daily (polypharmacy). Ageing produces important changes in the cardiovascular system and represents the most potent single cardiovascular risk factor. Cardiovascular diseases (CVDs) constitute the greatest burden for older people, their caregivers, and healthcare systems. Cardiovascular pharmacotherapy in older people is complex because age-related changes in body composition, organ function, homeostatic mechanisms, and comorbidities modify the pharmacokinetic and pharmacodynamic properties of many commonly used cardiovascular and non-cardiovascular drugs. Additionally, polypharmacy increases the risk of adverse drug reactions and drug interactions, which in turn can lead to increased morbi-mortality and healthcare costs. Unfortunately, evidence of drug efficacy and safety in older people with multimorbidity and polypharmacy is limited because these individuals are frequently underrepresented/excluded from clinical trials. Moreover, clinical guidelines are largely written with a single-disease focus and only occasionally address the issue of coordination of care, when and how to discontinue treatments, if required, or how to prioritize recommendations for patients with multimorbidity and polypharmacy. This review analyses the main challenges confronting healthcare professionals when prescribing in older people with CVD, multimorbidity, and polypharmacy. Our goal is to provide information that can contribute to improving drug prescribing, efficacy, and safety, as well as drug adherence and clinical outcomes.

The role of pharmacogenomics in contemporary cardiovascular therapy: a position statement from the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy.

There is a strong and ever-growing body of evidence regarding the use of pharmacogenomics to inform cardiovascular pharmacology. However, there is no common position taken by international cardiovascular societies to unite diverse availability, interpretation, and application of such data, nor is there recognition of the challenges of variation in clinical practice between countries within Europe. Aside from the considerable barriers to implementing pharmacogenomic testing and the complexities of clinically actioning results, there are differences in the availability of resources and expertise internationally within Europe. Diverse legal and ethical approaches to genomic testing and clinical therapeutic application also require serious thought. As direct-to-consumer genomic testing becomes more common, it can be anticipated that data may be brought in by patients themselves, which will require critical assessment by the clinical cardiovascular prescriber. In a modern, pluralistic and multi-ethnic Europe, self-identified race/ethnicity may not be concordant with genetically detected ancestry and thus may not accurately convey polymorphism prevalence. Given the broad relevance of pharmacogenomics to areas, such as thrombosis and coagulation, interventional cardiology, heart failure, arrhythmias, clinical trials, and policy/regulatory activity within cardiovascular medicine, as well as to genomic and pharmacology subspecialists, this position statement attempts to address these issues at a wide-ranging level.

Challenges in cardiovascular pharmacogenomics implementation: a viewpoint from the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy.

Pharmacogenomics promises to advance cardiovascular therapy, but there remain pragmatic barriers to implementation. These are particularly important to explore within Europe, as there are differences in the populations, availability of resources, and expertise, as well as in ethico-legal frameworks. Differences in healthcare delivery across Europe present a challenge, but also opportunities to collaborate on pharmacogenomics implementation. Clinical workforce upskilling is already in progress but will require substantial input. Digital infrastructure and clinical support tools are likely to prove crucial. It is important that widespread implementation serves to narrow rather than widen any existing gaps in health equality between populations. This viewpoint supplements the working group position paper on cardiovascular pharmacogenomics to address these important themes.

Antiproliferative effect of estrogen in vascular smooth muscle cells is mediated by Kruppel-like factor-4 and manganese superoxide dismutase.

The mitochondrial antioxidant enzyme manganese superoxide dismutase (MnSOD) and the zinc finger transcription factor Kruppel-like factor-4 (KLF4) are involved in the regulation of redox homeostasis, apoptosis and cell proliferation. We have shown that estrogen exerts antioxidative actions via induction of MnSOD in cultured rat aortic vascular smooth muscle cells (VSMC). The purpose of the present study was to investigate whether estrogen inhibits VSMC proliferation via alteration of KLF4 and MnSOD expression. In cultured rat aortic VSMC, estrogen binding to estrogen receptor-alpha led to rapid increase in KLF4 expression and reduction of cell proliferation by 50%. Protein separation revealed that KLF4 was shifted to the nucleus when VSMC were treated with estrogen. Estrogen-mediated induction of KLF4 and the antiproliferative effect involved activation of PI-3 kinase, Akt phosphorylation and induction of NO synthase activity. Experiments in freshly isolated denuded aortic segments revealed an increase in KLF4 abundance after estrogen treatment and demonstrated that eNOS is expressed in the media at low levels. Transfection experiments showed that estrogen-induced overexpression of MnSOD required KLF4 and that both KLF4 and MnSOD were indispensable for the observed antiproliferative effect of estrogen in VSMC. To confirm these data in vivo, we investigated neointima formation after carotid artery injury in wild-type (WT) and MnSOD+/- mice. Estrogen deficiency led to enhanced neointima formation and higher numbers of Ki67-positive proliferating cells in the neointima of ovariectomized WT and MnSOD+/- mice. Moreover, MnSOD+/- mice showed more extensive neointima formation and Ki67 immunostaining. Interestingly, estrogen replacement prevented neointima formation in WT mice but failed to completely inhibit neointima formation in MnSOD+/- mice. Cultured VSMC derived from MnSOD+/- mice showed enhanced proliferation as compared to WT VSMC, and estrogen treatment failed to inhibit proliferation in MnSOD+/- VSMC. In conclusion, these data demonstrate the importance of MnSOD and KLF4 for proliferation control in VSMC. Our results provide novel insights into how proliferation of VSMC is regulated by estrogen and may help to identify novel targets for the treatment of vascular diseases such as restenosis.