Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.34 (lipoprotein lipase)
 7,025 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There is growing evidence that dietary proteins may interfere with lipid metabolism. We therefore examined the effects of feeding obese Zucker rats a single cell protein (SCP) with low ratios of methionine:glycine and lysine:arginine for 6 weeks. SCP feeding reduced the hepatic steatosis and lowered the plasma transaminase levels when compared with casein-fed rats (controls). The fatty acid oxidation was increased in liver mitochondria and peroxisomes, whereas the activities of enzymes involved in lipogenesis and TAG biosynthesis were unaffected. SCP feeding affected the fatty acid composition of liver lipids and plasma, and reduced the mRNA levels of the fatty acid desaturases. The decreased gene expression of stearoyl-CoA desaturase suggested that the fatty acids were directed towards oxidation rather than esterification as TAG. The decreased mRNA levels of VLDL-receptor and lipoprotein lipase in the liver after SCP feeding suggested that the uptake of TAG-rich lipoprotein to the liver was decreased. To conclude, the reduced fatty liver by SCP feeding may be caused by the increased capacity for fatty acid beta-oxidation in the liver, combined with changed fatty acid composition and possibly a reduced hepatic clearance of circulating VLDL. An increased awareness of the effect of dietary proteins on lipid metabolism could be of relevance in future dietary treatment of non-alcoholic fatty liver disease.
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PMID:Dietary single cell protein reduces fatty liver in obese Zucker rats. 1834 5

N,N-dimethyl-n-octadecylamine borane 1 at 8 mg/kg/day, tetrakis-u-(trimethylamine boranecarboxylato)-bis(trimethyl-carboxyborane)-dicopper(II) 2 at 2.5 mg/kg/day and trimethylamine-carboxyborane 3 at 8 mg/kg/day were evaluated for their effects on bile lipids, bile acids, small intestinal absorption of cholesterol and cholic acid and liver and small intestinal enzyme activities involved in lipid metabolism. The agent administered orally elevated rat bile excretion of lipids, e.g. cholesterol and phospholipids, and compounds 2 and 3 increased the bile flow rate. These agents altered the composition of the bile acids, but there was no significant increase in lithocholic acid which is most lithogenic agent in rats. The three agents did decrease cholesterol absorption from isolated in situ intestinal duodenum loops in the presence of drug. Hepatic and small intestinal mucosa enzyme activities, e.g. ATP-dependent citrate lyase, acyl CoA cholesterol acyl transferase, cholsterol-7-alpha -hydroxylase, sn glycerol-3-phosphate acyl transferase, phosphatidylate phosphohydrolase, and lipoprotein lipase, were reduced. However, the boron derivatives 1 and 3 decreased hepatic HMG-CoA reductase activity, the regulatory enzyme for cholesterol synthesis, but the compounds had no effects on small intestinal mucosa HMG-CoA reductase activity. There was no evidence of hepatic cell damage afforded by the drugs based on clinical chemistry values which would induce alterations in bile acid concentrations after treatment of the rat.
Met Based Drugs 1995
PMID:The effects of boron derivatives on lipid absorption from the intestine and on bile lipids and bile acids of sprague dawley rats. 1847 47

The boronated nucleosides with varying bases and sugar moieties were shown to be potent hypolipidemic agents in rodents. The 3'- aminocynaoborane dideoxythymidine derivative caused reductions in serum cholesterol and triglyceride levels, tissue lipids, VLDL and LDL cholesterol levels while elevating HDL cholesterol levels in rodents. The agents suppressed rat hepatic acetyl CoA synthetase, HMG-CoA reductase, acyl-CoA cholesterol acyl transferase, phosphatidylate phosphohydrolase and lipoprotein lipase activities while elevating cholesterol-7alpha-hydroxylase activity from 25 to 100 muM.
Met Based Drugs 1996
PMID:The hypolipidemic activity of boronated nucleosides in male mice and rats. 1847 53

The purpose of this study was to explore the triacylglycerol (TG) deposition and lipoprotein lipase (LPL) activity in the adipose tissue of patients with muculoskeletal sarcoma. Subcutaneous adipose tissue was obtained from the thighs of 19 patients with musculoskeletal sarcomas (sarcoma group) and 20 patients with osteoarthritis of the hip joint (control group) at surgery. The adipose tissue was homogenized and aliquots of the homogenate were used to measure the TG content and to prepare an acetone/ether powder to measure the LPL activity. The TG content was higher, but not significantly, in the sarcoma group than in the control group. The LPL activity of the sarcoma group was significantly higher than that of the control group. The TG content of the sarcoma group correlated positively with the LPL activity. [35S]Methionine incorporation investigation showed that the rate of LPL synthesis was significantly higher in the sarcoma group than in the control group. These results indicated that LPL was up-regulated at the transcriptional/translational level, thus resulting in an increased TG deposition in the adipose tissue of patients with muculoskeletal sarcoma.
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PMID:The synthesis and activity of lipoprotein lipase in the subcutaneous adipose tissue of patients with musculoskeletal sarcomas. 1875 79

The effects of dietary supplementation with methionine and cystine on lipid metabolism, including the serum lipid concentration, were studied in Donryu rats subcutaneously implanted with an ascites hepatoma cell line (AH109A) for comparison with normal rats. A diet supplemented with 1.2% L-methionine or L-cystine to 20% casein was found to suppress the hepatoma-induced increases in serum triglyceride and total cholesterol concentration. The lipoprotein lipase activity in tissues was enhanced by dietary methionine and cystine, with no change in the mRNA level. Dietary methionine and cystine increased bile acid excretion into the feces with enhanced hepatic cholesterol 7alpha-hydroxylase activity. Dietary methionine and cystine affected the lipid metabolism differently in normal rats from hepatoma-bearing rats. These results suggest that dietary methionine and cystine each had a hypolipidemic effect against cancer-induced hyperlipidemia, and that the different actions observed in the hepatoma-bearing and normal rats may have been due to a metabolic abnormality caused by the cancer.
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PMID:Comparison of the effects on lipid metabolism of dietary methionine and cystine between hepatoma-bearing and normal rats. 2005 21

Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a transcription factor that regulates lipid metabolism and inflammatory responses. Certain PPARgamma ligands improve nonalcoholic steatohepatitis (NASH). The role of PPARgamma itself in NASH remains poorly understood. The functional consequences of PPARgamma in the development of steatohepatitis through gene deficiency or gene overexpression of PPARgamma delivered by adenovirus (Ad-PPARgamma) were examined. Our results show that PPARgamma-deficient (PPARgamma(+/-)) mice fed the methionine- and choline-deficient (MCD) diet developed more severe steatohepatitis than wild-type mice, and were unaffected by PPARgamma ligand rosiglitazone. Overexpression of PPARgamma delivered by Ad-PPARgamma attenuated steatohepatitis. This effect was associated with redistribution of fatty acid from liver to adipose tissue by enhancing expression of fatty acid uptake genes (fatty acid binding protein-4 (aP2), fatty acid translocase (CD36), lipoprotein lipase (LPL) and fatty acid transport protein-1 (FATP-1)) and lipogenic genes (sterol regulatory element binding protein isoform-1 (SREBP-1) and stearoyl-CoA desaturase isoform-1 (SCD-1)) in adipose tissue and to a lesser extent in liver. The anti-steatohepatitis action of PPARgamma was also mediated via regulating adipokines through suppressing tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) and inducing adiponectin. Moreover, PPARgamma activation suppressed hepatic lipoperoxide and reduced hepatic pro-inflammatory cytokines (TNF-alpha and IL-6) production. In conclusion, PPARgamma is an important endogenous regulator and potential therapeutic target for nutritional steatohepatitis.
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PMID:PPARgamma is essential for protection against nonalcoholic steatohepatitis. 2037 96

Rats subcutaneously implanted with AH109A hepatoma cells show hyperlipidemia with high concentrations of serum triglyceride and nonesterified fatty acid, suppression of lipoprotein lipase (LPL), and elevation of hormone-sensitive lipase (HSL) activities during the growth of the hepatoma. Supplementation of the diet with sulfur amino acids such as L: -methionine (Met) and L: -cystine (Cys) improved hyperlipidemia by restoring LPL and HSL activities. In the present study, we have attempted to examine the effects of sulfur amino acids on the activity and mRNA level of LPL and the activity of HSL using 3T3-L1 cells, which are known to differentiate to adipocytes. The adipocytes were incubated with various concentrations of Met, Cys or L: -cysteine (CysH) in the absence or presence of tumor necrosis factor-alpha (TNF-alpha). LPL activity was suppressed by TNF-alpha. In the absence of TNF-alpha, Met, Cys and CysH did not change the LPL activity. In the presence of TNF-alpha, Met and Cys significantly increased the LPL activity, and Met also enhanced the LPL mRNA level. HSL activity was also suppressed by TNF-alpha. In the absence of TNF-alpha, Met enhanced the HSL activity. In the presence of TNF-alpha, Met, Cys and CysH suppressed the HSL activity. Sulfur amino acids such as Met, Cys and CysH affected the LPL activity, mRNA level, and HSL activity in 3T3-L1 adipocytes. Some of these effects of sulfur amino acids were different between LPL and HSL, between the absence and the presence of TNF-alpha, and between 3T3-L1 adipocytes and the adipose tissue from rats.
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PMID:Effects of sulfur amino acids, L: -methionine, L: -cystine and L: -cysteine on lipoprotein lipase and hormone-sensitive lipase in differentiated mouse 3T3-L1 adipocytes. 2062

The effects of simultaneous dietary fish oil ingestion and sulfur amino acid (L-methionine and L-cystine) supplementation on serum lipid concentrations and various parameters related to the lipid metabolism were studied in Donryu rats subcutaneously implanted with an ascites hepatoma cell line, AH109A. A diet containing 10% fish oil was found to reduce serum triglyceride, total cholesterol, (very-low-density lipoprotein plus low-density lipoprotein)-cholesterol, phospholipid and nonesterified fatty acid (NEFA) concentrations in these animals, and dietary supplementation of 1.2% L-methionine and L-cystine also suppressed these serum lipid concentrations. Hepatic fatty acid synthesis and the availability of serum NEFA were decreased, and epididymal adipose tissue lipoprotein lipase (LPL) activity was elevated by dietary fish oil, while LPL activity in various tissues and hepatic fatty acid oxidation were increased by dietary sulfur amino acids, resulting in a reduction in the serum triglyceride concentration by dietary fish oil and sulfur amino acids, respectively. Dietary fish oil suppressed the hepatoma-induced increase in cholesterogenesis in the host liver, and dietary methionine and cystine enhanced bile acid excretion into feces, which were the causes of the hypocholesterolemic effect. In these serum lipid concentrations, there were significant effects of fish oil ingestion and sulfur amino acid supplementation, but no significant interaction between these two factors was seen. These results indicate that dietary fish oil and sulfur amino acid, L-methionine and L-cystine, have hypolipidemic effects in cancer-related hyperlipidemia, and that the effects of these two factors on the decrease in these serum lipid concentrations are additive; these two factors may affect the lipid metabolism via different pathways and mechanisms.
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PMID:Effects of simultaneous dietary fish oil ingestion and sulfur amino acid supplementation on the lipid metabolism in hepatoma-bearing rats with hyperlipidemia. 2092 47

Polysorbates are frequently used in biotherapeutic formulations. Interest in assessing their stability, in particular the impact of their degradation products on the stability of therapeutic proteins, has been steadily growing in the past decade. The work presented summarizes a case study of a monoclonal antibody formulation that demonstrated a simultaneous loss of polysorbate and an increase in methionine oxidation. Spiking studies were conducted to determine both the cause and a potential mitigation for the monoclonal antibody (mAb) oxidation and polysorbate 80 (PS80) loss. The results indicated that a different source material exhibited different rates of mAb oxidation and PS80 loss and that in all evaluated materials, the addition of edetate disodium to the formulation mitigated both observed issues. The mAb was assessed for the presence of lipases and lipoprotein lipase was detected at low levels. It is proposed that edetate disodium was effective in mitigating the mAb oxidation and PS80 loss by chelating calcium in the formulation and therefore decreasing the activity of the lipases.
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PMID:Edetate Disodium as a Polysorbate Degradation and Monoclonal Antibody Oxidation Stabilizer. 3050 82


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