Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0028754 (obesity)
 124,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The uncoupling protein (UCP) 2 gene is expressed in adipose tissues and skeletal muscles, which are important sites for variations in energy expenditure. The objective of the current study was to examine the potential impact of a C-->T substitution in exon 4, resulting in an alanine to valine substitution at codon 55, on the Metabolic Syndrome in 284 unrelated Swedish men born in 1944. The subjects were genotyped using PCR amplification of the exon 4 region of the UCP2 gene followed by digestion with the restriction enzyme EclHK1. The allelic frequencies were 0.56 for allele Ala and 0.44 for allele Val. No association was found between the Ala55Val SNP and obesity and blood levels of insulin, glucose, and lipids as well as blood pressure and circulating hormones. From these data, we conclude that the C-->T substitution in exon 4 of the UCP2 gene does not contribute to the predisposition to be affected by the Metabolic Syndrome.
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PMID:Lack of association between the uncoupling protein-2 Ala55Val gene polymorphism and phenotypic features of the Metabolic Syndrome. 1238 72

Nonalcoholic fatty liver disease, an entity that includes nonalcoholic steatohepatitis, is typically a benign, indolent condition. However, in a subset of patients, the clinical course may progress to advanced cirrhosis, end-stage liver disease, or hepatocellular carcinoma. Unfortunately, the pathogenesis, natural history, and potential therapies for these disorders remain poorly understood. Identifying patients who should be targeted for potential treatment remains difficult. Liver biopsy should be considered to assess the degree of hepatic inflammation and fibrosis, because physical examination findings, biochemical parameters, and the results of radiographic studies have been shown to correlate poorly with the severity of steatohepatitis and fibrosis. Although there is some evidence suggesting that obesity, diabetes mellitus, older age, and perhaps an aspartate transaminase:alanine aminotransaminase ratio higher than 1 may be predictors of more advanced fibrosis, histology remains the gold standard. Most patients with simple hepatic steatosis appear to follow a benign course and probably do not require aggressive therapy. Conversely, patients with steatohepatitis with extensive inflammation and fibrosis are the patients who are most likely to benefit from effective therapies. The most commonly recommended treatment is weight loss. Existing data suggest that rapid weight loss may promote hepatic inflammation and fibrosis; therefore, gradual weight loss should be recommended. Large, randomized, controlled trials evaluating the long-term histologic impact and clinical outcomes of weight loss strategies are lacking. Potentially promising pharmacologic therapies include insulin-sensitizing oral hypoglycemic agents such as metformin and the thiazolidenediols, antihyperlipidemic agents such as gemfibrozil or 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, vitamin E and other antioxidants, ursodeoxycholic acid, and betaine. As with weight loss, data regarding the efficacy of these pharmacologic options are limited. In addition, there are no widely accepted guidelines to help direct the clinician in the optimal use of these agents in patients with nonalcoholic fatty liver diseases.
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PMID:Therapeutic Options in Nonalcoholic Fatty Liver Disease. 1240 79

The molecular basis of ligand recognition by the melanocortin 4 receptor (MC4R) has not been fully defined. In this study, we investigated the molecular determinants of MC4R ligand binding, employing a large array of ligands, using three approaches. First, molecular modeling of the receptor was used to identify Phe284, in transmembrane (TM) 7, as a potential site of ligand interaction. Mutation of Phe284 to alanine reduced binding affinity and potency of peptides containing L-Phe by up to 71-fold but did not appreciably affect binding of linear peptides containing D-Phe, consistent with a hydrophobic interaction between the Phe7 of alpha-melanocyte-stimulating hormone and Phe284. Second, we examined the effect of a naturally occurring mutation in TM3 (I137T) that is linked to obesity. This mutation decreased affinity and potency of cyclic, rigid peptides but not more flexible peptides, consistent with an indirect effect of the mutation on the tertiary structure of the receptor. Third, we examined the residues that support ligand selectivity for the MC4R over the MC3R. Mutation of Ile125 (TM3) of the MC4R to the equivalent residue of the MC3R (phenylalanine) selectively decreased affinity and potency of MC4R-selective ligands. This effect was mirrored by the reciprocal MC3R mutation F157I. The magnitude of this effect indicates that this locus is not of major importance. However, it is considered that an isoleucine/phenylalanine mutation may affect the orientation of Asp122, which has been identified as a major determinant of ligand binding affinity. Thus, this study provides further characterization of the MC4R binding pocket.
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PMID:Molecular determinants of melanocortin 4 receptor ligand binding and MC4/MC3 receptor selectivity. 1260 99

New tool substances may help to unravel the physiological role of the human orphan receptor BRS-3 and its possible use as a drug target for the treatment of obesity and cancer. In continuation of our work on BRS-3, the solid- and solution-phase synthesis of a library of low molecular weight peptidomimetic agonists based on the recently developed short peptide agonist 4 is described. Functional potencies of the compounds were determined measuring calcium mobilization in a fluorometric imaging plate reader (FLIPR) assay. Focusing on the N-terminus, the d-Phe-Gln moiety of 4 was modified in a combinatorial SAR-oriented medicinal chemistry approach. With the incorporation of N-arylated glycine and alanine building blocks azaglycine, piperazine, or piperidine and the synthesis of semicarbazides and semicarbazones, a number of highly potent and selective compounds with a reduced number of peptide bonds were obtained, which also should have enhanced metabolic stability.
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PMID:Design of selective peptidomimetic agonists for the human orphan receptor BRS-3. 1272 54

Recent research suggests that the Pro12Ala variant in peroxisome proliferator-activated receptor-gamma2 (PPAR-gamma2) is associated with diabetes- and obesity-related traits, and that its effects may be modified by obesity status. We characterized this variant in a population-based sample of 1,441 middle-aged African-American individuals with respect to diabetes-, obesity-, and other cardiovascular-related traits, both cross-sectionally and prospectively. The overall frequency of Ala12 was 1.9% (95% CI 1.5-2.5%), significantly lower than in Caucasian populations. Consistent with previous findings in Caucasians, African Americans with type 2 diabetes tended to be less likely to have the Pro/Ala genotype than those without (odds ratio [OR] 0.64, 95% CI 0.34-1.20); however, this OR was not statistically significant. Among nonobese individuals, the Pro/Ala genotype was associated with significantly lower ln(insulin) (P = 0.001), lower ln(HOMA-IR) (homeostasis model assessment of insulin resistance) (P = 0.002), higher fasting glucose-to-insulin ratio (P = 0.005), and lower diastolic blood pressure (P = 0.02). Among overweight individuals (BMI 25-29.9 kg/m(2)), the Pro/Ala genotype was associated with greater BMI (P = 0.02), waist-to-hip ratio (P = 0.01), and waist circumference (P = 0.04). Among obese individuals, there was no association between any of the diabetes- or obesity-related traits and the Pro12Ala PPAR-gamma2 variant. We conclude that among nonobese African Americans, the Pro/Ala genotype is associated with markers of greater insulin sensitivity.
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PMID:Pro12Ala of the peroxisome proliferator-activated receptor-gamma2 gene is associated with lower serum insulin levels in nonobese African Americans: the Atherosclerosis Risk in Communities Study. 1276 72

Peroxisome proliferator-activated receptor gamma (PPARgamma)-2 is a member of the nuclear hormone receptor superfamily that is expressed predominantly in adipocytes and is thought to have a role in energy homeostasis, adipogenesis, and insulin sensitivity. A functional single nucleotide polymorphism (SNP) that predicts a proline to alanine substitution (Pro12Ala) within the coding region of this gene has previously been associated with obesity and type 2 diabetes in several populations. In this study, we identified several novel SNPs in the promoter region of PPARgamma2 and genotyped them, along with the previously identified Pro12Ala SNP. In 241 nondiabetic Pima subjects, the Pro12Ala was associated with whole-body insulin action (P = 0.05), hepatic insulin action (P = 0.03), and fasting plasma insulin concentrations (P = 0.01). One of the promoter SNPs positioned within a putative E2 box was in high linkage disequilibrium (/D'/ = 0.98) with the Pro12Ala. This promoter SNP was similarly associated with whole-body insulin action (P = 0.04) and hepatic insulin action (P = 0.05), but not fasting plasma insulin concentrations. Functional studies in transfected 3T3-L1 cells demonstrated that this single base substitution in the putative E2 box significantly altered transcriptional activity from a luciferase reporter construct. These data indicate that this promoter SNP, via its effect on PPARgamma2 expression, may also have functional consequences on PPARgamma2-activated pathways, and perhaps both the promoter SNP and the Pro12Ala contribute to PPARgamma2-related phenotypes.
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PMID:A functional variant in the peroxisome proliferator-activated receptor gamma2 promoter is associated with predictors of obesity and type 2 diabetes in Pima Indians. 1282 58

Genetic variation of fatty acid binding protein 2 (FABP2) may contribute to the high prevalence of obesity and Type II diabetes in Tonga. To explore this we assessed the frequency of the FABP2 Ala54Thr polymorphism, obesity, and Type II diabetes in Tongans and possible inter-relationships. We investigated 1022 Tongan subjects, 433 men and 589 women aged 15-85 years, to identify possible associations between the FABP2 Ala54Thr polymorphism, obesity, Type II diabetes, BMI, glucose tolerance and standard lipid variables. The prevalence of the polymorphism was compared with that reported for other ethnic populations (studies from: Japanese, Finnish, African American, Native Canadian and Inuit, Swedish, Guadeloupe Indians, European males, and Caucasian populations). We found that 84% of the Tongan men and 93% of the Tongan women were overweight or obese (BMI> or =25kg/m2). The mean BMI+/-SD was not significantly different among those who were and were not carrying the Thr allele (males: Ala/Ala 30.4+/-5.4 and Thr carriers 29.8+/-5.1; females: Ala/Ala 33.8+/-6.4 and Thr carriers 33.6+/-5.1). The genotype frequencies were 76.2% Ala/Ala, 22.8% Ala/Thr, and 1.0% Thr/Thr. The Alal/Ala frequency is higher than the prevalences reported for all populations studied. The Thr allele was significantly associated with lower total cholesterol and LDL cholesterol in both sexes and in women also with lower HDL cholesterol. We conclude that there is a high prevalence of the FABP2 Ala54Thr polymorphism in Tongans. The polymorphism may be involved in lipid metabolism as the Thr allele is associated with low total and LDL cholesterol levels in this population.
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PMID:Obesity, Type II diabetes and the Ala54Thr polymorphism of fatty acid binding protein 2 in the Tongan population. 1285 23

The BETA2/NeuroD1 gene product is a transcription factor, a member of a helix-loop-helix (HLH) family that is specifically expressed in the endocrine pancreas. HLH and homeobox proteins are involved in the development and function of pancreatic islets cells. Mice homozygous for a targeted disruption of BETA2/NeuroD1 showed abnormal pancreatic islet morphogenesis and developed overt diabetes. Mutations in the NeuroD/BETA2 gene were linked to the development of type 2 diabetes (T2DM). The aims of the study were to determine the allele and genotype frequency of Ala45Thr polymorphism of BETA2/NeuroD1 in a Polish population and to examine the role of this amino acid variant in the genetic susceptibility to T2DM. We included 394 individuals into this study: 223 T2DM patients with the age at diagnosis above 35 years and 171 controls without a family history of T2DM. The fragment of the gene, corresponding to the Ala45Thr amino acid variant, was amplified by polymerase chain reaction. Alleles and genotypes were determined based on electrophoresis of the specific restriction enzyme EcoI57 DNA digestion products. Differences in distribution between the groups were examined by chi(2) test. The frequencies of the Ala and Thr alleles in T2DM patients (62% and 37.9%) were similar to those in the controls (65.5% and 34.5%; p=0.32). Similarly, there was no difference between the groups when we analyzed the genotype distribution (p=0.24). The stratification analysis based on family history of T2DM, obesity, and age of diagnosis did not show any difference between the groups. In conclusion, the frequency of Ala45Thr polymorphism in this studied Polish population is similar to its frequency in other Caucasians. We did not find evidence that the Ala45Thr polymorphism of BETA2/NeuroD1 played a role in the risk of T2DM in the examined Polish population.
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PMID:The Ala45Thr polymorphism of BETA2/NeuroD1 gene and susceptibility to type 2 diabetes mellitus in a Polish population. 1286 11

To investigate the associations between obesity and serum hepatic enzyme activities, we measured total body fat (TBF), body mass index (BMI), and hepatic biochemical parameters in 732 apparently healthy adults. TBF was assessed using a body fat analyzer. Serum activities of alanine and aspartate aminotransferase (ALT and AST), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), and lactate dehydrogenase (LD) were determined by standard spectrophotometric methods. Mean activities (+/- SD) of serum ALT and AST in men with high fatness were 51.2 +/- 12.6 U/L and 32.9 +/- 9.2 U/L, which were significantly higher than those in men with low fatness (23.5 +/- 7.4 U/L and 22.5 +/- 7.8 U/L, p < 0.01). Of 147 men with high fatness, 56 (38.1%) had serum ALT levels above the upper limit of normal, whereas only 9.5% (31/328) of men with low or desirable fatness showed elevated serum ALT activities (p < 0.01). Serum ALT, AST, and GGT activities correlated significantly with TBF in both overweight men and women. Among subjects having high TBF, those with fatty liver showed significantly higher incidence of elevated hepatic enzymes, compared to those without fatty liver. In short, elevated serum hepatic enzyme activities are associated with TBF and a high prevalence of fatty liver is observed in subjects with elevated TBF.
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PMID:Association between elevated serum hepatic enzyme activity and total body fat in obese humans. 1295 39

The peroxisome proliferator-activated receptor gamma (PPAR gamma) is a critical regulator of adipogenesis. PPAR gamma+/- mice are resistant to high-fat diet-induced obesity and thus PPAR gamma may mediate physiological responses to dietary fat in other mammals. The aim of this study was to determine whether the human PPAR gamma proline to alanine substitution polymorphism (Pro12Ala) modifies the association between dietary fat and adiposity and plasma lipids. Subjects (n=2141) were controls selected for three case-control studies nested within the Nurses' Health Study, a large ongoing prospective cohort study. Associations between intake of total fat, fat subtypes and BMI were different in PPAR gamma 12Ala variant allele-carriers compared with non-carriers. Among homozygous wild-type Pro/Pro individuals, those in the highest quintile of total fat intake, had significantly higher mean body mass index (BMI) compared with those in the lowest quintile (27.3 versus 25.4 kg/m2, respectively; P-trend<0.0001) whereas among 12Ala variant allele-carriers there was no significant trend observed between dietary fat intake and BMI (P-trend=0.99; P-interaction=0.003). In contrast, intake of monounsaturated fat was not associated with BMI among homozygous wild-type women but was inversely associated with BMI among 12Ala variant allele-carriers (mean in lowest quintile=27.6 versus mean in highest quintile=25.5 kg/m2; P-trend=0.006; P-interaction=0.003). The relationship between dietary fat intake and plasma lipid concentrations also differed according to PPAR gamma genotype. These data suggest that PPAR gamma genotype is an important factor in physiological responses to dietary fat in humans.
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PMID:Interaction between a peroxisome proliferator-activated receptor gamma gene polymorphism and dietary fat intake in relation to body mass. 1450 27


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