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Inhibition of Cholesterol Production but Not of Nonsterol Isoprenoid Products Induces Neuronal Cell Death
Author(s) -
Michikawa Makoto,
Yanagisawa Katsuhiko
Publication year - 1999
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1999.0722278.x
Subject(s) - squalene , programmed cell death , mevalonic acid , reductase , cholesterol , biology , apoptosis , hmg coa reductase , sterol , biochemistry , coenzyme a , viability assay , mevalonate pathway , intracellular , hydroxymethylglutaryl coa reductase , microbiology and biotechnology , enzyme
Deficiency of nonsterol isoprenoids, intermediate metabolites of the cholesterol biosynthetic pathway, has been known to cause an inhibition of DNA synthesis and cell growth, and to induce apoptosis in nonneuronal cells. To investigate whether this is also the case in neurons, we examined the effect of a 3‐hydroxy‐3‐methylglutaryl coenzyme A (HMG‐CoA) reductase inhibitor on the viability of neuronal cultures prepared from fetal rat brains. Treatment with compactin, a competitive inhibitor of HMG‐CoA reductase, induced neuronal death in a dose‐dependent manner. Concurrent treatment with cholesterol, β‐migrating very low density lipoprotein, mevalonate, or squalene substantially inhibited the induction of neuronal death by compactin. Cell death was also induced by treatment with squalestatin, which specifically inhibits cholesterol biosynthesis at a site down‐stream from the generation of nonsterol metabolites. Furthermore, squalestatin‐induced neuronal death was inhibited by concurrent incubation with squalene but not mevalonate. In contrast, cell growth of proliferating cells such as NIH 3T3 and PC12 cells was exclusively dependent on the level of nonsterol isoprenoid products and not that of cholesterol. The results of this study clearly indicate that the viability of neurons, different from that of nonneuronal cells, depends on the intracellular cholesterol content and not on the intermediate nonsterol isoprenoid products.