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

Our group has recently demonstrated (Gesta, S., Simon, M., Rey, A., Sibrac, D., Girard, A., Lafontan, M., Valet, P., and Saulnier-Blache, J. S. (2002) J. Lipid Res. 43, 904-910) the presence, in adipocyte conditioned-medium, of a soluble lysophospholipase d-activity (LPLDact) involved in synthesis of the bioactive phospholipid lysophosphatidic acid (LPA). In the present report, LPLDact was purified from 3T3F442A adipocyte-conditioned medium and identified as the type II ecto-nucleotide pyrophosphatase phosphodiesterase, autotaxin (ATX). A unique ATX cDNA was cloned from 3T3F442A adipocytes, and its recombinant expression in COS-7 cells led to extracellular release of LPLDact. ATX mRNA expression was highly up-regulated during adipocyte differentiation of 3T3F442A-preadipocytes. This up-regulation was paralleled by the ability of newly differentiated adipocytes to release LPLDact and LPA. Differentiation-dependent up-regulation of ATX expression was also observed in a primary culture of mouse preadipocytes. Treatment of 3T3F442A-preadipocytes with concentrated conditioned medium from ATX-expressing COS-7 cells led to an increase in cell number as compared with concentrated conditioned medium from ATX non-expressing COS-7 cells. The specific effect of ATX on preadipocyte proliferation was completely suppressed by co-treatment with a LPA-hydrolyzing phospholipase, phospholipase B. Finally, ATX expression was found in mature adipocytes isolated from mouse adipose tissue and was substantially increased in genetically obese-diabetic db/db mice when compared with their lean siblings. In conclusion, the present work shows that ATX is responsible for the LPLDact released by adipocytes and exerts a paracrine control on preadipocyte growth via an LPA-dependent mechanism. Up-regulations of ATX expression with adipocyte differentiation and genetic obesity suggest a possible involvement of this released protein in the development of adipose tissue and obesity-associated pathologies.
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PMID:Autotaxin is released from adipocytes, catalyzes lysophosphatidic acid synthesis, and activates preadipocyte proliferation. Up-regulated expression with adipocyte differentiation and obesity. 1264 76

Autotaxin (ATX) is a member of the ecto-nucleotide pyrophosphatase/phosphodiesterase (NPP) family and is a lysophospholipase D that cleaves the choline headgroup from lysophosphatidylcholine to generate the bioactive lipid lysophosphatidic acid (LPA). Enhanced expression of ATX and specific receptors for LPA in numerous cancer cell types has created an interest in studying ATX as a potential chemotherapeutic target. Likewise, ATX has been linked to several additional human diseases including multiple sclerosis, diabetes, obesity, neuropathic pain, and Alzheimer's disease. ATX inhibitors reported to date consist of metal ion chelators, lipid-like product analogs, and non-lipid small molecules. In the current research, we examined the pharmacology of the best of our previously reported non-lipid small molecule inhibitors. Here, these six inhibitors were studied utilizing the synthetic fluorescent lysophospholipid substrate FS-3, the nucleotide substrate pNP-TMP and the endogenous substrate LPC (16:0). All six compounds inhibited FS-3 hydrolysis >or=50%, whereas only three inhibited the hydrolysis of pNP-TMP to this degree. None of the six compounds blocked LPC 16:0 hydrolysis within the desired 50% inhibition range. The most potent analog (5, H2L 7905958) displayed an IC(50) of 1.6microM (K(i)=1.9microM, competitive inhibition) with respect to ATX-mediated FS-3 hydrolysis and an IC(50) of 1.2microM (K(i)=K(i)(')=6.5microM, non-competitive inhibition) against ATX-mediated pNP-TMP hydrolysis. All six inhibitors were specific for ATX as they were without affect on two additional lipid preferring NPP isoforms.
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PMID:Characterization of non-lipid autotaxin inhibitors. 2000 24

Body weight is tightly regulated by food intake and energy dissipation, and obesity is related to decreased energy expenditure (EE). Herein, we show that nucleotide pyrophosphatase/phosphodiesterase 2 (ENPP2, autotaxin) is an adipose-derived, secreted enzyme that controls adipose expansion, brown adipose tissue (BAT) function, and EE. In mice, Enpp2 was highly expressed in visceral white adipose tissue and BAT and is downregulated in hypertrophied adipocytes/adipose tissue. Enpp2(+/-) mice and adipocyte-specific Enpp2 knockout mice fed a high-fat diet showed smaller body weight gains and less insulin resistance than control mice fed the same diet. BAT was functionally more active and EE was increased in Enpp2-deficient mice. In humans, ENPP2 expression in subcutaneous fat and ENPP2 levels in serum were reduced in obese subjects. Taken together, our results establish ENPP2 as an adipose-derived, secreted enzyme that regulates adipose obesity and systemic metabolism. They also suggest ENPP2 could be a useful therapeutic target for the treatment of metabolic disease.
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PMID:ENPP2 contributes to adipose tissue expansion and insulin resistance in diet-induced obesity. 2496 10