Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.5 (neuropathy target esterase)
 1,070 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the effects of a novel acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor, NTE-122 (trans-1,4-bis[[1-cyclohexyl-3-(4-dimethylamino phenyl)ureido]methyl]cyclohexane), on ACAT activities in macrophages originating from several species and high-density lipoprotein (HDL)-induced cholesterol efflux in phorbol 12-myristate 13-acetate (PMA)-treated THP-1 cells. NTE-122 inhibited cell-free ACAT activities in human PMA-treated THP-1 cells and mouse J774.1 cells with IC50 values of 0.88 and 360 nM, respectively. NTE-122 competively inhibited the ACAT activity in PMA-treated THP-1 cells. NTE-122 also inhibited cellular ACAT activities in PMA-treated THP-1 cells, rat peritoneal macrophages and J774.1 cells with IC50 values of 3.5, 84 and 6800 nM, respectively. Furthermore, NTE-122 prevented cholesterol accumulation in PMA-treated THP-1 cells incubated with acetylated low density lipoprotein, simultaneously with HDL, while it caused accumulation of a significant amount of free cholesterol in the absence and even in the presence of HDL. NTE-122 also enhanced HDL-induced cholesterol efflux from established foam cells converted from PMA-treated THP-1 cells. These results suggest that NTE-122, capable of inhibiting macrophage ACAT activity in humans more strongly than those in the other species, exhibits anti-atherogenic effects by preventing the foam cell formation and enhancing the foam cell regression in humans.
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PMID:Effects of NTE-122, a novel acyl-CoA:cholesterol acyltransferase inhibitor, on cholesterol esterification and high-density lipoprotein-induced cholesterol efflux in macrophages. 1020 51

Sulfonylureas are generally used in the therapeutic treatment of non-insulin-dependent diabetes mellitus. Little is known, however, whether they also affect the lipid metabolism. Using glibenclamide (GB), a typical sulfonylurea, we have investigated its effects on the lipid metabolism in macrophages, J774 and phorbol ester-treated THP-1 cells. In the whole-cell assay system for cholesteryl ester (CE) accumulation that is induced by addition of chemically modified low-density lipoprotein (LDL), such as Ac-LDL and ox-LDL, GB effectively inhibited the CE accumulation of J774 cells in dose-dependent manners. The inhibition was resulted from increase in free cholesterol but not from change in total cholesterol amount. The results suggest that GB acts on acyl-CoA: cholesterol acyltransferase (ACAT) and inhibits its activity. To confirm the possibility, we then tested GB by another assay system using ACAT that was solubilized from the cells and reconstituted into the liposome composed of phosphatidyl choline- cholesterol. GB inhibition was not so much effective as those by CI-976 and NTE-122, known ACAT inhibitors, but the inhibition was complete in the presence of 100 microM GB. Using cell homogenates of PMA-stimulated THP-1 cells, GB also inhibited the ACAT activity to the level of undifferentiated THP-1 cells. These results indicate that GB acts as ACAT inhibitor but the chemical structure is quite different from the conventional ACAT inhibitors, suggesting it can be a seed to generate potential ACAT inhibitors which do not exhibit toxicity in adrenal gland.
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PMID:[Glibenclamide inhibits cholesterol metabolism in macrophage]. 1062 72

Cytosolic phospholipase A(2)alpha (cPLA(2)alpha), one of the three subtypes of cPLA(2) (alpha, beta and gamma), is thought to be a rate-limiting enzyme in eicosanoid biosynthesis. We developed a novel and potent cPLA(2)alpha inhibitor with an optically active pyrrolidine, termed pyrrophenone, and characterized this compound in detail using enzyme and cellular assay systems. Pyrrophenone, which shows strong inhibition of cPLA(2)alpha activity, is one of the most potent cPLA(2)alpha inhibitors reported to date. Similar inhibitory potencies for cPLA(2)alpha were obtained from three different assays. The inhibitory activity of pyrrophenone is two or three orders of magnitude more potent than arachidonyl trifluoromethyl ketone (AACOCF(3)) under the same assay conditions. Pyrrophenone shows reversible inhibition of cPLA(2)alpha and displays no characteristics of the slow-binding inhibition observed for AACOCF(3). Pyrrophenone also inhibited the esterase and lysophospholipase activities of cPLA(2)alpha. However, the inhibition by pyrrophenone of 14 kDa secretory PLA(2)s, types IB and IIA, was over two orders of magnitude less potent than that for cPLA(2)alpha. Pyrrophenone strongly inhibited arachidonic acid release in calcium ionophore (A23187)-stimulated human monocytic cells (THP-1 cells) in a dose-dependent manner with an IC(50) value of 0.024 microM, followed by suppression of eicosanoid synthesis, and also showed dose-dependent inhibition for interleukin-1-induced prostaglandin E(2) synthesis in human renal mesangial cells with an IC(50) value of 0.0081 microM. The mechanism of inhibition of eicosanoid synthesis in these cell-based assays was due to inhibition of only one step of arachidonic acid release without any effect on cyclo-oxygenase or lipoxygenase pathways. These results suggest that pyrrophenone could be a potential therapeutic agent for inflammatory diseases.
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PMID:Characterization of a novel inhibitor of cytosolic phospholipase A2alpha, pyrrophenone. 1196 73