Metabolic syndrome (MetS) is associated with increased risk for cardiovascular disease (CVD). Mexican Americans (MA) exhibit increases in CVD risk factors compared with non-Hispanic whites (NHW), but few data exist comparing the relation of MetS to subclinical CVD, for example, left ventricular (LV) mass. Asymptomatic subjects (104 MA and 101 NHW, 52.
View Article and Find Full Text PDFMexican Americans have exhibited increases in various coronary heart disease risk factors compared to European Americans but have also had reportedly lower coronary heart disease mortality from vital statistics studies. We hypothesized this apparent paradox might relate to lower levels of subclinical disease in Mexican Americans. A total of 105 adult Mexican Americans (42 men and 63 women, age 46 +/- 14 years) and 100 European Americans (59 men and 41 women, age 50 +/- 11 years) were studied using blood tests, transthoracic echocardiography, and computed tomography coronary artery calcium (CAC) scans.
View Article and Find Full Text PDFIn addition to lowering blood pressure, telmisartan, an angiotensin (AT(1)) receptor blocker, has recently been shown to exert pleiotropic effects as a partial agonist of nuclear peroxisome proliferator-activated receptor gamma (PPAR gamma). On the basis of these findings and docking pose similarity between telmisartan and rosiglitazone in PPAR gamma active site, two classes of benzimidazole derivatives were designed and synthesized as dual PPAR gamma agonist/angiotensin II antagonists for the possible treatment of metabolic syndrome. Compound 4, a bisbenzimidazole derivative showed the best affinity for the AT(1) receptor with a K(i) = 13.
View Article and Find Full Text PDFBackground: Mexican-Americans (MA) exhibit increases in various cardiovascular disease (CVD) risk factors compared to non-Hispanic Whites (NHW), yet are reported to have lower CVD mortality rates. Our aim was to help explain this apparent paradox by evaluating endothelial function and urine albumin levels in MA and NHW.
Methods: One hundred-five MA and 100 NHW adults were studied by brachial artery flow-mediated dilatation (FMD), blood and urine tests.
The angiogenic, neovascular proliferative retinopathies, proliferative diabetic retinopathy (PDR), and age-dependent macular degeneration (AMD) complicated by choroidal neovascularization (CNV), also termed exudative or "wet" AMD, are common causes of blindness. The antidiabetic thiazolidinediones (TZDs), rosiglitazone, and troglitazone are PPARgamma agonists with demonstrable antiproliferative, and anti-inflammatory effects, in vivo, were shown to ameliorate PDR and CNV in rodent models, implying the potential efficacy of TZDs for treating proliferative retinopathies in humans. Activation of the angiotensin II type 1 receptor (AT1-R) propagates proinflammatory and proliferative pathogenic determinants underlying PDR and CNV.
View Article and Find Full Text PDFType II diabetes is a heterogeneous disease where environment and genetics are important factors for the expression of the disease. The high cost for treating complications of diabetes is a burden for public health systems and governments worldwide. Type II diabetes has been causing debilitation worldwide for many decades, and a single drug that safely treats the disease has yet to be discovered.
View Article and Find Full Text PDFExpert Opin Investig Drugs
March 2007
In animal experiments, the potent antioxidant and free radical scavenger alpha-lipoic acid has been shown to cause weight loss, ameliorate insulin resistance and atherogenic dyslipidemia, as well as to lower blood pressure, all of these being components of the metabolic syndrome. Recent investigations on its mechanisms of action indicate that alpha-lipoic acid can affect central and peripheral modulation of 5'-AMP-activated protein kinase, activate PPAR-alpha and PPAR-gamma, modulate PPAR-regulated genes and upregulate the expression of PPAR-gamma mRNA and protein in cardiac tissue and aorta smooth muscle. To a large extent, these findings can explain the observed beneficial metabolic effects of alpha-lipoic acid, supporting its potential application as a therapeutic agent for the treatment of the metabolic syndrome.
View Article and Find Full Text PDFThe thiazolidinediones constitute a family of synthetic compounds that act as high-affinity ligands for persoxisome proliferator-activated receptor-gamma (PPAR-gamma), a member of the nuclear hormone receptor family. Although originally developed to facilitate glucose control in patients with Type 2 diabetes, a number of studies showed that these agents effectively inhibited epithelial cell proliferation and tissue inflammation. Many of the initial cell growth inhibition studies were conducted with malignant epithelial cells from various sites; however, in addition to malignant epithelial cells, other studies showed that rapidly proliferating epidermal keratinoctyes in culture were also sensitive to the growth-inhibiting action of these moieties.
View Article and Find Full Text PDFA series of novel derivatives of potent antioxidant vitamin, alpha-lipoic acid, and related analogues were designed, synthesized, and evaluated for their PPARgamma agonist activities. Compounds 9a and the water soluble analogue11e were found to be potent PPARgamma agonists. Compound 9a appeared to have a significant role in improving insulin sensitivity and reducing triglyceride levels in fa/fa rats as well as inhibited proliferation of a variety of normal and neoplastic cultured human cell types.
View Article and Find Full Text PDFThe metabolic syndrome consists of a combination of cardiovascular risk factors that include hyperglycemia with or without type 2 diabetes mellitus, visceral obesity, elevated blood pressure, and atherogenic dyslipidemia. These interrelated disorders and their associated lipotoxicity, oxidative stress, and inflammatory state predispose to a constellation of cardiovascular conditions leading to high risk of heart attack, stroke, renal failure, blindness, and lower extremity amputation. Visceral obesity, a prime risk factor for type 2 diabetes and a major component of the metabolic syndrome, potentiates atherogenesis, atherosclerosis, organ lipotoxicity, and oxidative tissue damage.
View Article and Find Full Text PDFThe metabolic syndrome, defined as a cluster of visceral obesity, insulin resistance, dyslipidemia and elevated blood pressure, is associated with pro-thrombotic, pro-atherogenic and inflammatory risk factors that predispose to cardiovascular disease. Although activators of the peroxisome proliferator-activated receptors (PPARalpha,gamma,delta) in various combinations are under development for treating the metabolic syndrome, they are hampered by adverse effects related to increased adipogenesis, weight gain, fluid overload and carcinogenesis. The recent discovery that telmisartan and irbesartan, antihypertensive angiotensin II type 1 receptor (AT1-R) blockers (ARBs), were uniquely capable of activating PPARgamma, has provided a novel approach to addressing the multifactorial components of the metabolic syndrome.
View Article and Find Full Text PDFThe authors conducted a prospective, open-label, pilot trial of the effects of the antidiabetic thiazolidinedione (TZD) rosiglitazone in two patients with moderate to severe plaque psoriasis. Case 1: A lean, euglycemic 43-year-old nondiabetic man with a 2-year history of plaque psoriasis presented with lesions involving 10% of his body surface (Figures 1A, 1B, 1C). He had no other chronic or acute medical problems.
View Article and Find Full Text PDFJ Pharmacol Exp Ther
December 2005
Recent studies have demonstrated that orally administered thiazolidinedione ligands of the peroxisome proliferator-activated receptor-gamma can ameliorate clinical features of psoriasis in humans. Thiazolidinediones also inhibit the proliferation of psoriatic keratinocytes in monolayer and organ culture, and at least one of these agents (troglitazone) inhibits epidermal hyperplasia of human psoriatic skin transplanted to severe-combined immunodeficient (SCID) mice. In the present study, we show that a novel, synthetic, thiazoladinedione derivative, BP-1107 ({2-[4-(2,4-dioxo-thiazolidin-5-ylmethyl)-phenoxy]-ethyl}-methyl-amide), is capable of inhibiting psoriatic hyperplasia in the SCID mouse transplant model after topical application.
View Article and Find Full Text PDFPurpose: To determine the efficacy of the peroxisome proliferator-activated receptor gamma agonist, pioglitazone, in inhibiting corneal neovascularization.
Methods: Twenty-six adult male Sprague-Dawley rats were randomly divided into three groups. Each group received intrastromal polymer micropellets containing one of the following: Group 1, no active ingredient (n=10); Group 2, vascular endothelial growth factor (VEGF) (n=7); Group 3, VEGF and pioglitazone (n=9).
BACKGROUND: Ligands of the peroxisome proliferator-activated receptor-gamma (PPARgamma) induce apoptosis in activated T-lymphocytes and exert anti-inflammatory effects in glial cells. Preclinical studies have shown that the thiazolidinedione pioglitazone, an FDA-approved PPARgamma agonist used to treat type 2 diabetes, delays the onset and reduces the severity of clinical symptoms in experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis (MS). We therefore tested the safety and therapeutic potential of oral pioglitazone in a patient with secondary MS.
View Article and Find Full Text PDFNovel thiazolidinedione derivatives of the potent antioxidant, alpha-lipoic (thioctic, 1,2-dithiolane) acid, were prepared. The prototype N-(2-[4-[2,4-dioxo(1,3-thiazolidin-5-yl)methyl]phenoxy]ethyl)-5-(1,2-dithiolan-3-yl)- N-methylpentanamide (designated BP-1003), and dithioester derivatives thereof were shown to be potent activators of peroxisome proliferator-activated receptor gamma (PPARgamma) (EC(50) range 15-101 nM) and modest activators of PPARalpha (EC(50) 5 microM). Both the relatively hydrophobic dithiolane prototype, BP-1003, and its water-soluble dithioglycinate derivative, BP-1017, were shown to inhibit the proliferation of human keratinocytes and suppress the production of interleukin-2 by human peripheral lymphocytes to a greater extent than the antidiabetic thiazolidinedione, rosiglitazone.
View Article and Find Full Text PDFExpert Opin Investig Drugs
March 2004
The discovery that the insulin-sensitising thiazolidinediones (TZDs), specific peroxisome proliferator-activated receptor-gamma (PPARgamma) agonists, have antiproliferative, anti-inflammatory and immunomodulatory effects has led to the evaluation of their potential use in the treatment of diabetic complications and inflammatory, proliferative diseases in non-insulin-resistant, euglycaemic individuals. Apart from improving insulin resistance, plasma lipids and systemic inflammatory markers, ameliorating atherosclerosis and preventing coronary artery restenosis in diabetic subjects, currently approved TZDs have been shown to improve psoriasis and ulcerative colitis in euglycaemic human subjects. These data imply that the activation of PPAR-gamma may improve cardiovascular risk factors and cardiovascular outcomes in both insulin-resistant diabetic and non-diabetic individuals.
View Article and Find Full Text PDFThe metabolic syndrome is a common precursor of cardiovascular disease and type 2 diabetes that is characterized by the clustering of insulin resistance, dyslipidemia, and increased blood pressure. In humans, mutations in the peroxisome proliferator-activated receptor-gamma (PPARgamma) have been reported to cause the full-blown metabolic syndrome, and drugs that activate PPARgamma have proven to be effective agents for the prevention and treatment of insulin resistance and type 2 diabetes. Here we report that telmisartan, a structurally unique angiotensin II receptor antagonist used for the treatment of hypertension, can function as a partial agonist of PPARgamma; influence the expression of PPARgamma target genes involved in carbohydrate and lipid metabolism; and reduce glucose, insulin, and triglyceride levels in rats fed a high-fat, high-carbohydrate diet.
View Article and Find Full Text PDFThis study was undertaken to evaluate the effects of thiazolidinediones (TZD) on keratinocyte proliferation, motility, and matrix metalloproteinase (MMP) production. Rosiglitazone (a potent TZD) inhibited both proliferation and motility as well as elaboration of MMP-1 and MMP-9. Inhibition was obtained with keratinocytes in monolayer culture and human skin in organ culture.
View Article and Find Full Text PDFPioglitazone, like other thiazolidinediones, is an insulin-sensitizing agent that activates the peroxisome proliferator-activated receptor gamma and influences the expression of multiple genes involved in carbohydrate and lipid metabolism. However, it is unknown which of these many target genes play primary roles in determining the antidiabetic and hypolipidemic effects of thiazolidinediones. To specifically investigate the role of the Cd36 fatty acid transporter gene in the insulin-sensitizing actions of thiazolidinediones, we studied the metabolic effects of pioglitazone in spontaneously hypertensive rats (SHR) that harbor a deletion mutation in Cd36 in comparison to congenic and transgenic strains of SHR that express wild-type Cd36.
View Article and Find Full Text PDFThe development of clinical symptoms in multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE) involves T-cell activation and migration into the central nervous system, production of glial-derived inflammatory molecules, and demyelination and axonal damage. Ligands of the peroxisome proliferator-activated receptor (PPAR) exert anti-inflammatory effects on glial cells, reduce proliferation and activation of T cells, and induce myelin gene expression. We demonstrate in two models of EAE that orally administered PPARgamma ligand pioglitazone reduced the incidence and severity of monophasic, chronic disease in C57BL/6 mice immunized with myelin oligodendrocyte glycoprotein peptide and of relapsing disease in B10.
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