These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Increased cholesterol synthesis in Chinese hamster ovary cells deficient in peroxisomes.
    Author: van Heusden GP, van Beckhoven JR, Thieringer R, Raetz CR, Wirtz KW.
    Journal: Biochim Biophys Acta; 1992 Jun 05; 1126(1):81-7. PubMed ID: 1606178.
    Abstract:
    In a previous study we have shown that Chinese hamster ovary (CHO) cells deficient in intact peroxisomes, lack the nonspecific lipid transfer protein (nsL-TP; sterol carrier protein 2) (van Heusden, G.P.H., Bos, K., Raetz, C.R.H. and Wirtz, K.W.A. (1990) J. Biol. Chem. 265, 4105-4110). The consequences of the absence of peroxisomes and of nsL-TP on intracellular cholesterol metabolism have been investigated in two peroxisome-deficient CHO cell lines (CHO-82 and CHO-78). Compared with wild-type cells (CHO-K1), the incorporation of [3H]acetate into cholesterol was 3-fold higher in the CHO-82 cells and 2-fold higher in the CHO-78 cells. In agreement with an increased synthesis of cholesterol, a 2-3-fold higher 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase activity was measured in both mutant cell lines. On the other hand, addition of low density lipoprotein (LDL), mevalonate (30 mM) or 25-hydroxycholesterol (2 micrograms/ml) to cells grown in lipoprotein-deficient serum, demonstrated that in both mutant cell lines the down-regulation of HMG-CoA reductase and of cholesterol synthesis were comparable to that in wild-type cells. These results strongly suggest that, in addition to down-regulation by LDL-derived cholesterol, mevalonate and 25-hydroxycholesterol, HMG-CoA reductase activity is under control of peroxisomes and/or nsL-TP.
    [Abstract] [Full Text] [Related] [New Search]