Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0242339 (dyslipidemia)
 13,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Statins and fibrates constitute the two major families of lipid-lowering agents. Statins are widely used for the treatment of pure hypercholesterolaemia while fibrates are used for the treatment of hypertriglyceridemia. Both drugs are also used for the treatment of mixed dyslipidemia. Some fibrates efficiently lower serum LDL-cholesterol. Statins inhibit HMG-CoA reductase and decrease cellular cholesterol synthesis. The resulting lower intracellular cholesterol concentration induces the activation of SREBP thus inducing the over expression and transcription of the LDL receptor gene. This over expression of the LDL receptor in the liver increases the clearance of circulating LDL thus decreasing the LDL-cholesterol plasma levels. The effects of fibrates on lipid metabolism are entirely due to their capacity to activate PPAR-alpha and to induce the over expression of genes containing a PPRE in their promoter. Fibrates decrease triglyceride concentrations by increasing the beta-oxidation of fatty acids in the liver and by decreasing triglyceride-VLDL synthesis. Fibrates also decrease triglycerides by increasing the hydolysys of triglycerides in chylomicron and VLDL through their capacity to increase and to decrease the lipoprotein lipase and the apo C-III transcription, respectively. Fibrates could decrease triglycerides partly by inducing apo A-V over-expression. These molecules increase HDL-cholesterol by increasing apo A-I and apo A-II transcription. Therefore the mechanisms of action of statins and fibrates depend on their capacity to modulate the expression of genes controlling lipoprotein metabolism.
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PMID:[Anti-cholesterol agents, new therapeutic approaches]. 1474 68

Retinoids, derivatives of vitamin A, induce hypertriglyceridemia through decreased clearance of very low-density lipoprotein by a lipoprotein lipase (LPL)-dependent pathway. The retinoid X receptor (RXR) gamma isotype, which is highly expressed in skeletal muscle, may be important in mediating the effects of retinoids on skeletal muscle metabolism and triglyceride (TG) clearance. RXRgamma-deficient (-/-) mice had lower fasting plasma TG levels compared with wild-type littermates (33.1 +/- 2.0 vs. 51.7 +/- 6.3 mg/dl, respectively; P < 0.05). Skeletal muscle LPL activity was higher in RXRgamma mice (18.7 +/- 2.2 vs. 13.3 +/- 1.3 nmol free fatty acids/min.g; P = 0.03), but LPL activity was not different in adipose and cardiac tissue, suggesting a specific effect of RXRgamma in skeletal muscle. In addition, when exposed to a 14-wk high-fat diet, RXRgamma -/- mice had less weight gain, which was entirely due to lower fat mass (11.9 +/- 1.8 vs. 14.4 +/- 1.1 g; P = 0.01), and leptin levels were also lower in the RXRgamma -/- mice (17.6 +/- 5.0 vs. 30.9 +/- 6.4 ng/ml; P = 0.03). These data suggest that RXRgamma -/- mice are resistant to gain in fat mass in response to high-fat feeding. This occurs, at least in part, through up-regulation of LPL activity in skeletal muscle. An understanding of the mechanisms governing the role of RXR in TG disposal and metabolism may lead to the rational design of RXR-selective agonists and antagonists that may be useful in common disorders such as dyslipidemia and obesity.
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PMID:Retinoid X receptor gamma-deficient mice have increased skeletal muscle lipoprotein lipase activity and less weight gain when fed a high-fat diet. 1508 32

We investigated the biological activity of Dr. Reddy's Research Foundation (DRF) 2519, a benzoxazinone analogue of the thiazolidinedione class of compounds. In the in vitro transactivation assay, DRF 2519 showed interesting dual activation of Peroxisome Proliferator Activated Receptor (PPAR) alpha and gamma. In insulin-resistant ob/ob mouse model, DRF 2519 showed significant alleviation of insulin resistance and dyslipidemia, which is better than rosiglitazone. Fatty Zucker rats treated with DRF 2519 showed better reduction of plasma insulin, triglyceride and free fatty acid levels than those treated with rosiglitazone. In addition, these rats were able to clear plasma lipids better when challenged with exogenous lipid (i.v.). DRF 2519 treatment resulted in improved plasma lipid profiles in high-fat-fed Sprague-Dawley rats. Treated rats showed better plasma lipid clearance and hepatic triglyceride secretion. When compared to DRF 2519, fenofibrate was comparatively less efficacious while rosigltiazone showed no activity in these models. In ex vivo studies, DRF 2519 showed induction of liver acyl CoA oxidase mRNA and increase in lipoprotein lipase (LPL) protein expression and activity in adipose tissue. In the in vitro studies, DRF 2519 inhibited the lipid biosynthesis and secretion of apolipoprotein B from human hepatoma (Hep)G2 cells. It also enhanced insulin-induced relaxation of rat aortic smooth muscle. These results indicate that DRF 2519, a dual activator of PPAR-alpha and gamma, could be an interesting development candidate in the management of metabolic disorders and associated complications.
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PMID:Antidiabetic and hypolipidemic potential of DRF 2519--a dual activator of PPAR-alpha and PPAR-gamma. 1514 Jun 37

The prevalence of obesity has become increasingly common worldwide, in particular western countries. Obesity, together with insulin resistance, leads to metabolic syndrome in which other coronary risk factors including hyperlipidemia and hypertension cluster in one individual. Hyperlipidemia in metabolic syndrome is characterized increased triglyceride(TG), decreased HDL-C, and small dense LDL, called dyslipidemic triad. Dyslipidemia is attributable to increased flux of free fatty acids to the liver, which promotes TG synthesis, thus VLDL production. Increased VLDL, together with decreased lipoprotein lipase activity due to insulin resistance, causes accumulation of TG-rich lipoproteins, including proatherogenic remnants. Further, increased activities of cholesteryl ester transfer protein and hepatic triglyceride lipase results in low HDL-C and small dense LDL. Initial treatment should be directed to modify life style(weight loss and increased physical activity). Then, pharmacological intervention should be considered when the initial treatment is not fully successful. Fibrate derivatives are considered to be ideal to correct dyslipidemic triad. In addition, potent statins(HMG-CoA reductase inhibitor) can be alternative in metabolic syndrome subjects with elevated LDL-C levels.
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PMID:[Dyslipidemia in metabolic syndrome]. 1520 47

Hypertriglyceridemia is a common pathological condition in humans of mostly unknown etiology. Here we report induction of dyslipidemia characterized by severe hypertriglyceridemia as a result of point mutations in human apolipoprotein A-I (apoA-I). Adenovirus-mediated gene transfer in apoA-I-deficient (apoA-I(-)(/)(-)) mice showed that mice expressing an apoA-I[E110A/E111A] mutant had comparable hepatic mRNA levels with WT controls but greatly increased plasma triglyceride and elevated plasma cholesterol levels. In addition, they had decreased apoE and apoCII levels and increased apoB48 levels in very low-density lipoprotein (VLDL)/intermediate-density lipoprotein (IDL). Fast protein liquid chromatography (FPLC) analysis of plasma showed that most of cholesterol and approximately 15% of the mutant apoA-I were distributed in the VLDL and IDL regions and all the triglycerides in the VLDL region. Hypertriglyceridemia was corrected by coinfection of mice with recombinant adenoviruses expressing the mutant apoA-I and human lipoprotein lipase. Physicochemical studies indicated that the apoA-I mutation decreased the alpha-helical content, the stability, and the unfolding cooperativity of both lipid-free and lipid-bound apoA-I. In vitro functional analyses showed that reconstituted HDL (rHDL) particles containing the mutant apoA-I had 53% of scavenger receptor class B type I (SR-BI)-mediated cholesterol efflux capacity and 37% capacity to activate lecithin:cholesterol acyltransferase (LCAT) as compared to the WT control. The mutant lipid-free apoA-I had normal capacity to promote ATP-binding cassette transporter A1 (ABCA1)-dependent cholesterol efflux. The findings indicate that subtle structural alterations in apoA-I may alter the stability and functions of apoA-I and high-density lipoprotein (HDL) and may cause hypertriglyceridemia.
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PMID:Substitutions of glutamate 110 and 111 in the middle helix 4 of human apolipoprotein A-I (apoA-I) by alanine affect the structure and in vitro functions of apoA-I and induce severe hypertriglyceridemia in apoA-I-deficient mice. 1530 43

Human lipoprotein lipase (LPL) deficiency causes profound hypertriglyceridemia and life-threatening pancreatitis. We recently developed an adult murine model for LPL deficiency: LPL -/- mice display grossly elevated plasma triglyceride (TG) levels (>200-fold) and very low high-density lipoprotein cholesterol (HDL-C < 10% of normal). We used this animal model to test the efficacy of adeno-associated virus-mediated expression of hLPL(S447X) (AAV1-LPL(S447X)) in muscle for the treatment of LPL deficiency. Intramuscular administration of AAV1-LPL(S447X) resulted in dose-dependent expression of hLPL protein and LPL activity (up to 33% of normal murine levels) in postheparin plasma. Remarkably, visible hyperlipidemia was resolved within 1 week; plasma TG was reduced to near-normal levels (from 99.0 to 1.8 mmol/L), and plasma HDL-C was increased 6-fold (from 0.2 to 1.1 mmol/L). At 8 months after administration of AAV1-LPL(S447X), an intravenous lipid challenge showed efficient, near-normal clearance of plasma TG. Histologic analyses of injected muscle further indicated that abnormal muscle morphology observed in LPL -/- mice was reversed after treatment. Expression of therapeutic levels of LPL(S447X), and the subsequent beneficial effect on plasma lipid levels, has lasted for more than 1 year. We therefore conclude that AAV1-mediated transfer of LPL(S447X) into murine skeletal muscle results in long-term near-correction of dyslipidemia associated with LPL deficiency.
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PMID:Long-term correction of murine lipoprotein lipase deficiency with AAV1-mediated gene transfer of the naturally occurring LPL(S447X) beneficial mutation. 1535 45

LSN862 is a novel peroxisome proliferator-activated receptor (PPAR)alpha/gamma dual agonist with a unique in vitro profile that shows improvements on glucose and lipid levels in rodent models of type 2 diabetes and dyslipidemia. Data from in vitro binding, cotransfection, and cofactor recruitment assays characterize LSN862 as a high-affinity PPARgamma partial agonist with relatively less but significant PPARalpha agonist activity. Using these same assays, rosiglitazone was characterized as a high-affinity PPARgamma full agonist with no PPARalpha activity. When administered to Zucker diabetic fatty rats, LSN862 displayed significant glucose and triglyceride lowering and a significantly greater increase in adiponectin levels compared with rosiglitazone. Expression of genes involved in metabolic pathways in the liver and in two fat depots from compound-treated Zucker diabetic fatty rats was evaluated. Only LSN862 significantly elevated mRNA levels of pyruvate dehydrogenase kinase isozyme 4 and bifunctional enzyme in the liver and lipoprotein lipase in both fat depots. In contrast, both LSN862 and rosiglitazone decreased phosphoenol pyruvate carboxykinase in the liver and increased malic enzyme mRNA levels in the fat. In addition, LSN862 was examined in a second rodent model of type 2 diabetes, db/db mice. In this study, LSN862 demonstrated statistically better antidiabetic efficacy compared with rosiglitazone with an equivalent side effect profile. LSN862, rosiglitazone, and fenofibrate were each evaluated in the humanized apoA1 transgenic mouse. At the highest dose administered, LSN862 and fenofibrate reduced very low-density lipoprotein cholesterol, whereas, rosiglitazone increased very low-density lipoprotein cholesterol. LSN862, fenofibrate, and rosiglitazone produced maximal increases in high-density lipoprotein cholesterol of 65, 54, and 30%, respectively. These findings show that PPARgamma full agonist activity is not necessary to achieve potent and efficacious insulin-sensitizing benefits and demonstrate the therapeutic advantages of a PPARalpha/gamma dual agonist.
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PMID:A peroxisome proliferator-activated receptor alpha/gamma dual agonist with a unique in vitro profile and potent glucose and lipid effects in rodent models of type 2 diabetes and dyslipidemia. 1583 17

Plasma fibrinogen level represents a strong cardiovascular risk factor and is regulated by an interplay of genetic and environmental factors. Hyperfibrinogenemia frequently occurs in cluster with dyslipidemia within the frame of insulin resistance syndrome (IRS) and type 2 diabetes mellitus. Genetic variants with a pleiotropic effect have been proposed to cause IRS features including hyperfibrinogenemia. We studied the influence of polymorphisms in lipoprotein lipase (LPL) gene, beta-fibrinogen gene (FIBB) and environmental factors on plasma fibrinogen levels in type 2 diabetes patients. 131 type 2 diabetes patients (mean age 62+/-10 years, 33% male) were genotyped for polymorphisms in LPL gene (intron 6 PvuII, intron 8 HindIII) and FIBB gene (-148C/T, -455G/A) by PCR-RFLP method. Fibrinogen was measured by thrombin coagulation method, albuminuria by immunoturbidimetric assay. Polymorphism LPL PvuII showed a gene-dose effect on fibrinogen levels, with the highest fibrinogen in P-P- homozygotes (p = 0.05, analysis of variance). P-carriers (P-P- and P+P- combined) had significantly higher fibrinogen levels compared with P+P+ homozygotes (3.74+/-1.40 g/l vs 3.06+/-1.20 g/l, p=0.03). Other studied polymorphisms were not significantly related to fibrinogen levels. Age- and sex-adjusted fibrinogenemia correlated significantly with albuminuria (r = 0.48, p=0.001), serum uric acid (r = 0.42, p=0.006) and serum creatinine (r = 0.32, p=0.04). Multiple stepwise linear regression identified interaction term of LPL PvuII and albuminuria as an independent predictor of fibrinogen level, explaining 18% of fibrinogen variance. Albuminuria thus appears to be the best predictor of fibrinogen plasma levels in type 2 diabetic patients. Relationship between albuminuria and fibrinogenemia may be modified by the genotype LPL PvuII, which also shows a weak association with plasma fibrinogen level in type 2 diabetes patients.
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PMID:Relationship among urinary albumin excretion rate, lipoprotein lipase PvuII polymorphism and plasma fibrinogen in type 2 diabetic patients. 1585 59

Hyperlipidemia and its treatment are currently recognized as important modulators of cardio-vascular mortality in the presence of disordered glucose control. On the other hand, the effects of hyperglycemia and its treatment on hyperlipidemia are not widely appreciated. Hyperglycemia is commonly associated with an increase in intestinal lipoproteins and a reduction in high-density lipoprotein (HDL). This could be a consequence of hyperglycemia-induced glycation of lipoproteins, which reduces the uptake and catabolism of the lipoproteins via the classical low-density lipoprotein (LDL) receptor. A high dietary carbohydrate load increases the glycation of intestinal lipoproteins, prolongs their circulation, and increases their plasma concentration. Hyperglycemia also leads to inhibition of lipoprotein lipase, further aggravating hyperlipidemia. Circulating advanced glycation end-products (AGEs) also bind lipoproteins and delay their clearance, a mechanism that has particularly been implicated in the dyslipidemia of diabetic nephropathy. As uptake via scavenger receptors is not inhibited, glycation increases the proportion of lipoproteins that are taken up via inflammatory cells and decreases the proportion taken up by hepatocytes via classical LDL receptors. This promotes the formation of atheromatous plaques and stimulates inflammation. Hyperglycemia increases the formation of oxidized LDL and glycated LDL, which are important modulators of atherosclerosis and cardiovascular death. The risk of cardiovascular death is increased by even short-term derangement of blood sugar control, owing perhaps to the glycation of lipoproteins and other critical proteins. Glycated LDL could prove very useful in measuring the effect of hyperglycemia on cardiovascular disease, its risk factors, and its complications. Comparing different glucose-lowering and lipid-lowering drugs in respect to their influence on glycated LDL could increase knowledge of the mechanism by which they alter cardiovascular risk.
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PMID:Hyperglycemia, lipoprotein glycation, and vascular disease. 1607 28

Dyslipidemia in the metabolic syndrome (MS) is considered to be one of the most important risk factors for atherosclerosis. It is characterized by hypertriglyceridemia, low concentration of plasma HDL-cholesterol, predominance of small dense LDL particles and an increased concentration of plasma apolipoprotein B (apoB). The pathogenesis of this type of dyslipidemia is partially explained, but its genetic background is still unknown. To evaluate the influence of cholesterol ester transfer protein (CETP) TaqIB polymorphism, lipoprotein lipase (LPL) PvuII and HindIII polymorphisms, hepatic lipase (LIPC) G-250A polymorphism and apolipoprotein C-III (APOC3) SstI gene polymorphism on lipid levels in dyslipidemia of the metabolic syndrome, 150 patients with dyslipidemia of metabolic syndrome were included. 96 % of patients had type 2 diabetes. The patients did not take any lipid lowering treatment. The exclusion criterion was the presence of any disease that could affect lipid levels, such as thyroid disorder, liver disease, proteinuria or renal failure. Gene polymorphisms were determined using the polymerase chain reaction and restriction fragment length polymorphisms. The genotype subgroups of patients divided according to examined polymorphisms did not differ in plasma lipid levels with the exception of apoB. The apoB level was significantly higher in patients with S1S1 genotype of APOC3 SstI polymorphism when compared with S1S2 group (1.10+/-0.26 vs. 0.98+/-0.21 g/l, p=0.02). Similarly, patients with H-H- genotype of LPL HindIII polymorphism had significantly higher mean apoB, compared with H+H- and H+H+ group (1.35+/-0.30 vs. 1.10+/-0.26 g/l, p=0.02). In the multiple stepwise linear regression analysis, apoB level seemed to be influenced by APOC3 SstI genotype, which explained 6 % of its variance. The present study has shown that the S1 allele of APOC3 SstI polymorphism and the H- allele of LPL HindIII polymorphism might have a small effect on apoB levels in the Central European Caucasian population with dyslipidemia of metabolic syndrome.
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PMID:Effect of gene polymorphisms on lipoprotein levels in patients with dyslipidemia of metabolic syndrome. 1634 38


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