| Autor: |
Cianflone K; McGill Unit for the Prevention of Cardiovascular Disease, Royal Victoria Hospital, Montreal, Quebec, Canada., Roncari DA, Maslowska M, Baldo A, Forden J, Sniderman AD |
| Jazyk: |
angličtina |
| Zdroj: |
Biochemistry [Biochemistry] 1994 Aug 16; Vol. 33 (32), pp. 9489-95. |
| DOI: |
10.1021/bi00198a014 |
| Abstrakt: |
Through their capacity to store fatty acids as triacylglycerol molecules, adipocytes serve a vital physiologic role. This study presents further evidence that this process can be modulated in human adipocytes by the adipsin/acylation stimulating protein (ASP) pathway and suggests a novel function for the product of this system--ASP. The data demonstrate the following: (1) ASP stimulates triacylglycerol synthesis within adipocytes, and this occurs to a greater extent in differentiating than undifferentiated cells (242% +/- 32% vs 168% +/- 11%, p < 0.01, respectively, at an ASP concentration of 88 ng/mL; (2) ASP does not affect the Km for triacylglycerol synthesis but does substantially increase Vmax; (3) when ASP is generated in vitro through incubation of its precursor proteins under appropriate conditions, triacylglycerol synthesis increases to the same extent as when plasma-purified ASP is added to the medium; (4) human adipocytes contain mRNA for the specific serine protease adipsin and the two precursor proteins C3 and factor B required to interact for the production of ASP; and (5) the extent to which cultured differentiating adipocytes produce ASP is proportional to the degree to which they have accumulated triacylglycerol mass during differentiation (r2 = 0.7523, p < 0.0005). These findings provide the first evidence for the existence of the adipsin/ASP pathway in human adipocytes, and this may markedly enhance our understanding of the processes which regulate triacylglycerol clearance from plasma. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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