Background-Oxidized low-density lipoprotein (ox-LDL) causes endothelial dysfunction in part by decreasing the availability of endothelial nitric oxide (NO). Although HMG CoA reductase inhibitors restore endothelial function by reducing serum cholesterol levels, it is not known whether they can also directly upregulate endothelial NO synthase (ecNOS) activity. Methods and Results-Human saphenous vein endothelial cells were treated with ox-LDL (50 g/mL thiobarbituric acid reactive substances 12 to 16 nmol/mg) in the presence of HMG CoA reductase inhibitors simvastatin and lovastatin. In a time-dependent manner, ox-LDL decreased ecNOS mRNA and protein levels (91Ϯ4% and 67Ϯ8% reduction after 72 hours, respectively). Both simvastatin (1 mol/L) and lovastatin (10 mol/L) upregulated ecNOS expression by 3.8-fold and 3.6-fold, respectively, and completely prevented its downregulation by ox-LDL. These effects of simvastatin on ecNOS expression correlated with changes in ecNOS activity. Although L-mevalonate alone did not affect ecNOS expression, cotreatment with L-mevalonate completely reversed ecNOS upregulation by simvastatin. Actinomycin D studies revealed that simvastatin stabilized ecNOS mRNA ( 1/2 , 43 versus 35 hours). Nuclear run-on assays and transient transfection studies with a Ϫ1.6 kb ecNOS promoter construct showed that simvastatin did not affect ecNOS gene transcription. Conclusions-Inhibition

Abstract--The three peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors of the nuclear hormone receptor superfamily. They share a high degree of structural homology with all members of the superfamily, particularly in the DNA-binding domain and ligand-and cofactor-binding domain. Many cellular and systemic roles have been attributed to these receptors, reaching far beyond the stimulation of peroxisome proliferation in rodents after which they were initially named. PPARs exhibit broad, isotype-specific tissue expression patterns. PPAR␣ is expressed at high levels in organs with significant catabolism of fatty acids. PPAR␤/␦ has the broadest expression pattern, and the levels of expression in certain tissues depend on the extent of cell proliferation and differentiation. PPAR␥ is expressed as two isoforms, of which PPAR␥2 is found at high levels in the adipose tissues, whereas PPAR␥1 has a broader expression pattern. Transcriptional regulation by PPARs requires heterodimerization with the retinoid X receptor (RXR). When activated by a ligand, the dimer modulates transcription via binding to a specific DNA sequence element called a peroxisome proliferator response element (PPRE) in the promoter region of target genes. A wide variety of natural or synthetic compounds was identified as PPAR ligands. Among the synthetic ligands, the lipidlowering drugs, fibrates, and the insulin sensitizers, thiazolidinediones, are PPAR␣ and PPAR␥ agonists, respectively, which underscores the important role of PPARs as therapeutic targets. Transcriptional control by PPAR/RXR heterodimers also requires interaction with coregulator complexes. Thus, selective action of PPARs in vivo results from the interplay at a given time point between expression levels of each of the three PPAR and RXR isotypes, affinity for a specific promoter PPRE, and ligand and cofactor availabilities.

SUMMARY Proinflammatory stimuli elicit rapid transcriptional responses via transduced signals to master regulatory transcription factors. To explore the role of chromatin-dependent signal transduction in the atherogenic inflammatory response, we characterized the dynamics, structure and function of regulatory elements in the activated endothelial cell epigenome. Stimulation with tumor necrosis factor alpha prompted a dramatic and rapid global redistribution of chromatin activators to massive de novo clustered enhancer domains. Inflammatory super enhancers formed by NF-κB accumulate at the expense of immediately decommissioned, basal endothelial super enhancers, despite persistent histone hyperacetylation. Mass action of enhancer factor redistribution causes momentous swings in transcriptional initiation and elongation. A chemical genetic approach reveals a requirement for BET bromodomains in communicating enhancer remodeling to RNA polymerase and orchestrating the transition to the inflammatory cell state, demonstrated in activated endothelium and macrophages. BET bromodomain inhibition abrogates super enhancer mediated inflammatory transcription, atherogenic endothelial responses and atherosclerosis in vivo.

The American Heart Association (AHA) and the American Diabetes Association (ADA) have each published guidelines for cardiovascular disease prevention: the ADA has issued separate recommendations for each of the cardiovascular risk factors in patients with diabetes, and the AHA has shaped primary and secondary guidelines that extend to patients with diabetes. This statement will attempt to harmonize the recommendations of both organizations where possible but will recognize areas in which AHA and ADA recommendations differ. Diabetes Care 30:162-172, 2007D iabetes is a disease defined by abnormalities of fasting or postprandial glucose and is frequently associated with disorders of the eyes, kidneys, nerves, and circulatory system. Circulatory disorders associated with diabetes include coronary heart disease (CHD), stroke, peripheral arterial disease, cardiomyopathy, and congestive heart failure. Diabetes generally results in early death from cardiovascular diseases (CVDs). In 1999, the American Diabetes Association (ADA) and the American Heart Association (AHA) published a joint statement with the National Heart, Lung, and Blood Institute (NHLBI), the National Institute of Diabetes and Digestive and Kidney Diseases, and the Juvenile Diabetes Foundation International indicating the need for multiorganizational cooperation for prevention of CVD in patients with diabetes (1). The present statement represents a joint response of the ADA and AHA to this challenge.The ADA and AHA each have published guidelines for CVD prevention that overlap with the present statement: The ADA has issued separate recommendations for each of the cardiovascular risk factors in patients with diabetes, and the AHA has shaped primary and secondary guidelines that extend to patients with diabetes. The present document will attempt to harmonize the recommendations of both organizations where possible but will recognize areas in which ADA and AHA recommendations differ.Clear clinical trial evidence published over the past decade suggests that broadbased treatment of dyslipidemia, hypertension, and hypercoagulability (as well as interventional cardiology and cardiovascular surgery during the acute coronary syndrome [2]) can improve the event-free survival rate in people with diabetes who already have clinical CVD. However, a much smaller body of clinical trial data addresses the issue of primary prevention of CVD in patients with diabetes and no known CVD. This is a critical issue because patients with diabetes have twice the risk of incident myocardial infarction and stroke as that of the general population. Furthermore, large numbers of people with diabetes do not survive their first event, and if they do survive, their mortality rate over the subsequent months to years is generally greater than that of the general population. As many as 80% of patients with type 2 diabetes will develop and possibly die of macrovascular disease. This represents a great societal cost, with major loss of life expectancy and quality of life (3,4). Although the i...

The metabolism of vitamin A and the diverse effects of its metabolites are tightly controlled by distinct retinoid-generating enzymes, retinoid-binding proteins and retinoid-activated nuclear receptors. Retinoic acid regulates differentiation and metabolism by activating the retinoic acid receptor and retinoid X receptor (RXR), indirectly influencing RXR heterodimeric partners. Retinoic acid is formed solely from retinaldehyde (Rald), which in turn is derived from vitamin A. Rald currently has no defined biologic role outside the eye. Here we show that Rald is present in rodent fat, binds retinol-binding proteins (CRBP1, RBP4), inhibits adipogenesis and suppresses peroxisome proliferator-activated receptor-c and RXR responses. In vivo, mice lacking the Rald-catabolizing enzyme retinaldehyde dehydrogenase 1 (Raldh1) resisted diet-induced obesity and insulin resistance and showed increased energy dissipation. In ob/ob mice, administrating Rald or a Raldh inhibitor reduced fat and increased insulin sensitivity. These results identify Rald as a distinct transcriptional regulator of the metabolic responses to a high-fat diet.Although vitamin A and its metabolite retinoic acid have therapeutic applications, frequent side effects limit their use 1-3 . In clinical trials involving β-carotene supplementation, worrisome increases in cardiovascular events and mortality have been noted, despite evidence suggesting possible beneficial vascular effects of this treatment 3 . These variable responses to retinoids probably derive from the fact that β-carotene and vitamin A (retinol) and their major metabolites-retinaldehyde (Rald) and retinoic acid-regulate diverse cellular responses, including development, immune function and vision 4,5 . The tight control of retinoid biology is evident in the elaborate system that governs the absorption, formation, transportation and action of these structurally and functionally distinct retinoid metabolites. Despite this, retinoids

Human ECs express PPARalpha, a potentially important regulator of atherogenesis through its transcriptional control of VCAM-1 gene expression. Such findings also have implications regarding the clinical use of lipid-lowering agents, like fibric acids, which can activate PPARalpha.

SUMMARY Heart failure (HF) is driven by the interplay between master regulatory transcription factors and dynamic alterations in chromatin structure. While pathologic gene transactivation in this context is known to be associated with recruitment of histone acetyl-transferases and local chromatin hyperacetylation, the role of epigenetic reader proteins in cardiac biology is unknown. We therefore undertook a first study of acetyl-lysine reader proteins, or bromodomains, in HF. Using a chemical genetic approach, we establish a central role for BET-family bromodomain proteins in gene control during HF pathogenesis. BET inhibition potently suppresses cardiomyocyte hypertrophy in vitro and pathologic cardiac remodeling in vivo. Integrative transcriptional and epigenomic analyses reveal that BET proteins function mechanistically as pause-release factors critical to activation of canonical master regulators and effectors that are central to HF pathogenesis and relevant to the pathobiology of failing human hearts. This study implicates epigenetic readers in cardiac biology and identifies BET co-activator proteins as therapeutic targets in HF.

Background Systematic data on discontinuation of statins in routine practice of medicine are limited. Objective To investigate reasons for statin discontinuation and the role of statin-related events (clinical events / symptoms thought to have been caused by statins) in routine care settings. Design A retrospective cohort study Setting Practices affiliated with one of two academic hospitals. Patients Adults who received a statin prescription between 01/01/2000 and 12/31/2008. Measurements Information on reasons for statin discontinuations was obtained from a combination of structured electronic medical record (EMR) entries and analysis of electronic provider notes by validated software. Results Statins were discontinued at least temporarily for 57,292 out of 107,835 patients. Statin-related events were documented for 18,778 (17.4%) patients. Statins were discontinued at least temporarily by 11,124 of these patients, 6,579 (59.1%) of whom were rechallenged with a statin over the subsequent 12 months. Most patients who were rechallenged (92.2%) were still taking a statin 12 months after the statin-related event. Among the 2,721 patients who were rechallenged with the same statin to which they had a statin-related event, 1,295 (47.6%) were on the same statin 12 months later, including 996 on the same or higher dose. Limitation Statin discontinuations and statin-related events were assessed in practices affiliated with two academic medical centers. Utilization of secondary data could have led to missing or misinterpreted data as a result of incomplete documentation. Natural language processing tools used to compensate for the low (30%) proportion of reasons for statin discontinuation documented in structured EMR fields are not perfectly accurate. Conclusion Statin-related events are commonly reported and often lead to their discontinuation. However, most patients who are rechallenged can tolerate statins long-term. This suggests that many of the statin-related events may have other etiologies, are tolerable or may be specific to individual statins rather than the entire drug class.