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)

11 beta-hydroxysteroid dehydrogenase type 1 (11 beta-HSD1) catalyzes the interconversion of biologically inactive 11 keto derivatives (cortisone, 11-dehydrocorticosterone) to active glucocorticoids (cortisol, corticosterone) in fat, liver, and other tissues. It is located in the intraluminal compartment of the endoplasmic reticulum. Inasmuch as an oxo-reductase requires NADPH, we reasoned that 11 beta-HSD1 would be metabolically interconnected with the cytosolic pentose pathway because this pathway is the primary producer of reduced cellular pyridine nucleotides. To test this theory, 11 beta-HSD1 activity and pentose pathway were simultaneously measured in isolated intact rodent adipocytes. Established inhibitors of NAPDH production via the pentose pathway (dehydroandrostenedione or norepinephrine) inhibited 11 beta-HSD1 oxo-reductase while decreasing cellular NADPH content. Conversely these compounds slightly augmented the reverse, or dehydrogenase, reaction of 11 beta-HSD1. Importantly, using isolated intact microsomes, the inhibitors did not directly alter the tandem microsomal 11 beta-HSD1 and hexose-6-phosphate dehydrogenase enzyme unit. Metabolites of 11 beta-HSD1 (corticosterone or 11-dehydrocorticosterone) inhibited or increased pentose flux, respectively, demonstrating metabolic interconnectivity. Using isolated intact liver or fat microsomes, glucose-6 phosphate stimulated 11 beta-HSD1 oxo-reductase, and this effect was blocked by selective inhibitors of glucose-6-phosphate transport. In summary, we have demonstrated a metabolic interconnection between pentose pathway and 11 beta-HSD1 oxo-reductase activities that is dependent on cytosolic NADPH production. These observations link cytosolic carbohydrate flux with paracrine glucocorticoid formation. The clinical relevance of these findings may be germane to the regulation of paracrine glucocorticoid formation in disturbed nutritional states such as obesity.
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PMID:Evidence that the 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD1) is regulated by pentose pathway flux. Studies in rat adipocytes and microsomes. 1623 47

Expression of both pro- and anti-inflammatory mediators are influenced by various factors such as rheumatic diseases, myocardial infarction, angina, aging, obesity and pharmacotherapy. This has therapeutic consequences. Clearance of highly bound and efficiently metabolized drugs may be reduced in the presence of inflammation amounting to increased circulating drug concentration. In the meantime, various cardiovascular receptors are down-regulated in the presence of pro-inflammatory mediators. Consequently, conditions such as rheumatoid arthritis, aging and obesity results in reduced response to drugs such as verapamil despite increased drug concentration. The inflammatory response is a complex cascade of non-specific events resulting in excessive generation of inflammatory mediators such as cytokines, C-reactive protein and nitric oxide by cells of the innate (macrophages, monocytes, neutrophils) and adaptive (T-lymphocytes) arms of the immune system. T-lymphocytes secrete various pro- and anti-inflammatory cytokines during an inflammatory event. In general, two distinct subpopulations of these T-helper cells exist, anti-inflammatory Th2 and pro-inflammatory Th1. As a common rule, Th1 cytokines suppress Th2 and vice-versa. Hence, a balance of these activities is desired. Drugs such as antirheumatoid agents, angiotensin II blockers and hydroxymethyl-glutaryl-CoA reductase inhibitor (statin) may help to restore the Th1/Th2 balance. In general, at least for some conditions, the challenge of therapeutic drug monitoring will be more useful if expression of inflammatory mediators is also taken into account. In addition, some of the intersubject variation in pharmacotherapy and clinical trails may be attributed to variations in the inflammatory mediator's concentration. A detail list of conditions and drugs that influence expression of the inflammatory mediators are provided and potential therapeutic consequences are discussed.
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PMID:Drug disease interactions: role of inflammatory mediators in disease and variability in drug response. 1640 7

Atherogenic dyslipidemia is one of the major components of the metabolic syndrome, a complex cluster of several risk factors within a single patient that according to the National Cholesterol Education Program (NCEP) Adult Treatment Panel III includes at least 3 of the following: large waist circumference, elevated triglyceride levels, low levels of high-density lipoprotein cholesterol (HDL-C), hypertension, and elevated fasting glucose levels, which are directly related to the incidence of coronary heart disease. Atherogenic dyslipidemia clinically presents as elevated serum triglyceride levels, increased levels of small dense low-density lipoprotein (sdLDL) particles, and decreased levels of HDL-C. An important component of atherogenic dyslipidemia is central obesity, which is defined as increased waist circumference and has recently been identified as a chief predictor of the metabolic syndrome in certain patients. Another recent study found that both body mass index and waist circumference were highly predictive of eventual development of the metabolic syndrome. Because atherogenic dyslipidemia usually precedes the clinical manifestation of the metabolic syndrome, strategies to treat it are the focus of pharmacologic intervention. For example, the 3-hydroxy-3-methylglutaryl coenzyme-A reductase inhibitors, commonly known as statins, benefit hypercholesterolemic patients who have atherogenic dyslipidemia that is associated with the metabolic syndrome. Pioglitazone, an antidiabetic agent that acts primarily by decreasing insulin resistance, improves sensitivity to insulin in muscle and adipose tissue and inhibits hepatic gluconeogenesis. Pioglitazone improves glycemic control while reducing circulating insulin levels. The investigational agent, rimonabant--a centrally and peripherally acting, selective cannabinoid type-1 receptor blocker--is the first therapy developed for managing several cardiovascular risk factors at one time. Rimonabant has shown promise in attacking atherogenic dyslipidemia from several vantage points by affecting glucose, HDL-C, triglycerides, and waist circumference in patients who are prone to atherogenic dyslipidemia.
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PMID:The metabolic basis of atherogenic dyslipidemia. 1647 58

The development of thromboses is one of the most common causes of morbidity and mortality in the Western world. The perturbation of haemostasis is the central event in the pathogenesis of all thromboses. Most patients with thromboses have no recognisable associated haemostatic disorders. However, some patients do manifest hereditary hypercoagulable states, which contribute to the development of thromboses as well as other clinical manifestations, such as miscarriages and foetal complications. The major determinants of thrombosis include both environmental influences and genetic factors. Transient or long-lasting environmental influences may play important roles in arterial and venous thromboses. Haemostatic perturbance may also be genetically determined and exert a life-long influence. Specific mutations of genes predisposed to thrombosis, such as deficiency of antithrombin, protein C, or protein S, are found in relatively small number of families. In the absence of genetic deficiencies, thrombosis occurs in the older population, largely within the context of marked environmental influences (such as surgery, obesity, and malignancy). In contrast, familial thrombosis, associated with gene mutation, is associated with a younger age. The general importance of gene polymorphism was established after the recognition of activated protein C resistance (APCR) due to gene polymorphism G1691A in factor V (Factor V Leiden). This single gene defect increases the risk of venous thrombosis, without interaction with other genetic or environmental risk factors. The development of APCR led to many other investigations of gene polymorphism, such as prothrombin 20210, thrombomodulin, factors in the coagulation and fibrinolytic system, glycoproteins of platelet membranes, as well as polymorphism C677T of methylene tetrahydrofolate reductase. The number of potential genetic risk factors for occlusive thrombotic disease has increased significantly. Most of these gene polymorphisms increase the risk of venous thrombosis but there is no strong evidence of their influence as far as arterial thrombosis is concerned.
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PMID:[Role of gene polymorphism in development of thromboses]. 1679 67

Essential fatty acids (EFAs), linoleic acid (LA), and alpha-linolenic acid (ALA) are essential for humans, and are freely available in the diet. Hence, EFA deficiency is extremely rare in humans. To derive the full benefits of EFAs, they need to be metabolized to their respective long-chain metabolites, i.e., dihomo-gamma-linolenic acid (DGLA), and arachidonic acid (AA) from LA; and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from ALA. Some of these long-chain metabolites not only form precursors to respective prostaglandins (PGs), thromboxanes (TXs), and leukotrienes (LTs), but also give rise to lipoxins (LXs) and resolvins that have potent anti-inflammatory actions. Furthermore, EFAs and their metabolites may function as endogenous angiotensin-converting enzyme and 3-hdroxy-3-methylglutaryl coenzyme A reductase inhibitors, nitric oxide (NO) enhancers, anti-hypertensives, and anti-atherosclerotic molecules. Recent studies revealed that EFAs react with NO to yield respective nitroalkene derivatives that exert cell-signaling actions via ligation and activation of peroxisome proliferator-activated receptors. The metabolism of EFAs is altered in several diseases such as obesity, hypertension, diabetes mellitus, coronary heart disease, schizophrenia, Alzheimer's disease, atherosclerosis, and cancer. Thus, EFAs and their derivatives have varied biological actions and seem to be involved in several physiological and pathological processes.
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PMID:Essential fatty acids: biochemistry, physiology and pathology. 1689 70

Because of increasingly sedentary lifestyles and diets higher in saturated fats, obesity and dyslipidemias are common and increasing in prevalence in Westernized countries. Longitudinal population-based studies clearly demonstrate that dyslipidemias and obesity, as well as factors such as hypertension, diabetes, and smoking, are major risk factors for atherosclerosis. Both clinical and animal models of endothelial dysfunction confirm that atherosclerosis leads to increased cerebrovascular and cardiovascular morbidity. Clinical studies with hypolipidemic agents demonstrate that hydroxy-3-methylglutaryl coenzyme A reductase inhibitors can decrease the risk of vascular morbidity. An increasing body of evidence from animal models demonstrates that hypercholesterolemia and atherosclerosis are risk factors for the development of erectile dysfunction (ED). This causal relationship between obesity and dyslipidemias with the development of ED in humans still needs further definition with convincing peer-reviewed scientific studies. The challenge for the future will be to define the benefit of controlling obesity and dyslipidemias on the development of ED and improvement of erectile function.
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PMID:Obesity, dyslipidemias and erectile dysfunction: a report of a subcommittee of the sexual medicine society of North America. 1694 22

Liver fatty acid-binding protein (L-Fabp) regulates murine hepatic fatty acid trafficking in response to fasting. In this study, we show that L-Fabp(-/-) mice fed a high-fat Western diet for up to 18 weeks are less obese and accumulate less hepatic triglyceride than C57BL/6J controls. Paradoxically, both control and L-Fabp(-/-) mice manifested comparable glucose intolerance and insulin resistance when fed a Western diet. Protection against obesity in Western diet-fed L-Fabp(-/-) mice was not due to discernable changes in food intake, fat malabsorption, or heat production, although intestinal lipid secretion kinetics were significantly slower in both chow-fed and Western diet-fed L-Fabp(-/-) mice. By contrast, there was a significant increase in the respiratory exchange ratio in L-Fabp(-/-) mice, suggesting a shift in energy substrate use from fat to carbohydrate, findings supported by an approximately threefold increase in serum lactate. Microarray analysis revealed increased expression of genes involved in lipid synthesis (fatty acid synthase, squalene epoxidase, hydroxy-methylglutaryl coenzyme A reductase), while genes involved in glycolysis (glucokinase and glycerol kinase) were decreased in L-Fabp(-/-) mice. Fatty acid synthase expression was also increased in the skeletal muscle of L-Fabp(-/-) mice. In conclusion, L-Fabp may function as a metabolic sensor in regulating lipid homeostasis. We suggest that L-Fabp(-/-) mice are protected against Western diet-induced obesity and hepatic steatosis through a series of adaptations in both hepatic and extrahepatic energy substrate use. (HEPATOLOGY 2006;44:1191-1205.).
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PMID:Protection against Western diet-induced obesity and hepatic steatosis in liver fatty acid-binding protein knockout mice. 1705 18

The Human Genome Project and subsequent identification of single nucleotide polymorphisms (SNPs) within populations has played a major role in predicting individual response to drugs (pharmacogenetics) leading to the concept of "personalized medicine." Nutritional genomics is a recent off-shoot of this genetic revolution that includes (1) nutrigenomics: the study of interaction of dietary components with the genome and the resulting proteonomic and metabolomic changes; and (2) nutrigenetics: understanding the gene-based differences in response to dietary components and developing nutraceuticals that are most compatible with health based on individual genetic makeup. Despite the extensive data on genetic polymorphisms in humans, its translation into medical practice has been slow because of the time required to accumulate population data on SNP incidence, understand the significance of a given SNP in disease, and develop suitable diagnostic tests. Nutrigenomics revitalized the field by showing that nutrients and botanicals can interact with the genome and modify subsequent gene expression, which has provided a great impetus for nutrigenetic research and nutraceutical development based on nutrigenetics. Polymorphisms in methlyene tetrahydrofolate reductase (MTHFR) (involved in folate metabolism), apolipoprotein E (Apo E) and ApoA1 (in cardiovascular disease), and leptin/leptin receptor (obesity) genes are some good examples for understanding basic nutrigenetics. Developing nutraceuticals to prevent and manage thrombosis risk in women with thrombophilic gene mutations are discussed in the context of the opportunities that exist at the nutrigenetic/pharmacogenetic interphase leading to "personalized nutrition." Further research on individual differences in genetic profiles and nutrient requirements will help establish nutrigenetics as an essential discipline for nutrition and dietetics practice.
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PMID:Nutrigenetics and nutraceuticals: the next wave riding on personalized medicine. 1724 Mar 15

The aldo-keto reductase 1B7 (AKR1B7) encodes an aldose-reductase that has been reported as a detoxification enzyme until now. We have demonstrated that AKR1B7 is differently expressed in various mouse white adipose tissues depending on their location. Its expression is associated with a higher ratio of preadipocytes vs. adipocytes. The cells that express AKR1B7 did not contain lipid droplets, and the expression level of akr1b7 was very low in mature adipocytes. We have defined the role of AKR1B7 in adipogenesis using either primary cultures of adipose stromal cells (containing adipocyte precursors) or the 3T3-L1 cell line. Under the same differentiation conditions, adipose stromal cells from tissues that expressed AKR1B7 had a decreased capacity to accumulate lipids compared with those that did not express it. Moreover, the overexpression of sense or antisense AKR1B7 in 3T3-L1 preadipocytes inhibited or accelerated, respectively, their rate of differentiation into adipocytes. In vivo experiments demonstrated that AKR1B7-encoding mRNA expression decreased in adipose tissues from mice where obesity was induced by a high-fat diet. All these results attributed for the first time a novel role to AKR1B7, which is the inhibition of adipogenesis in some adipose tissues.
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PMID:A novel inhibitory protein in adipose tissue, the aldo-keto reductase AKR1B7: its role in adipogenesis. 1727 90

Glucocorticoids (GCs) have a profound effect on adipose biology increasing tissue mass causing central obesity. The pre-receptor regulation of GCs by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) that activates cortisol from cortisone has been postulated as a fundamental mechanism underlying the metabolic syndrome mediating adipocyte hyperplasia and hypertrophy in the omental (OM) depot. Orbital adipose tissue (OF) is the site of intense inflammation and tissue remodelling in several orbital inflammatory disease states. In this study, we describe features of the GC metabolic pathways in normal human OF depot and compare it with subcutaneous (SC) and OM depots. Using an automated histological characterisation technique, OF adipocytes were found to be significantly smaller (parameters: area, maximum diameter and perimeter) than OM and SC adipocytes (P<0 x 001). Although immunohistochemical analyses demonstrated resident CD68+ cells in all three whole tissue adipose depots, OF CD68 mRNA and protein expression exceeded that of OM and SC (mRNA, P<0 x 05; protein, P<0 x 001). In addition, there was higher expression of glucocorticoid receptor (GR)alpha mRNA in the OF whole tissue depot (P<0 x 05). Conversely, 11beta-HSD1 mRNA together with the markers of late adipocyte differentiation (FABP4 and G3PDH) were significantly lower in OF. Primary cultures of OF preadipocytes demonstrated predominant 11beta-HSD1 oxo-reductase activity with minimal dehydrogenase activity. Orbital adipocytes are smaller, less differentiated, and express low levels of 11beta-HSD1 but abundant GRalpha compared with SC and OM. OF harbours a large CD68+ population. These characteristics define an orbital microenvironment that has the potential to respond to sight-threatening orbital inflammatory disease.
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PMID:Characterisation of 11beta-hydroxysteroid dehydrogenase 1 in human orbital adipose tissue: a comparison with subcutaneous and omental fat. 1728 28


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