Abstract Title:

Early embryonic lethality caused by targeted disruption of the 3-hydroxy-3-methylglutaryl-CoA reductase gene.

Abstract Source:

J Biol Chem. 2003 Oct 31 ;278(44):42936-41. Epub 2003 Aug 14. PMID: 12920113

Abstract Author(s):

Ken Ohashi, Jun-ichi Osuga, Ryuichi Tozawa, Tetsuya Kitamine, Hiroaki Yagyu, Motohiro Sekiya, Sachiko Tomita, Hiroaki Okazaki, Yoshiaki Tamura, Naoya Yahagi, Yoko Iizuka, Kenji Harada, Takanari Gotoda, Hitoshi Shimano, Nobuhiro Yamada, Shun Ishibashi

Article Affiliation:

Department of Metabolic Diseases, Faculty of Medicine, University of Tokyo, Tokyo 113-8655, Japan.

Abstract:

The endoplasmic reticulum (ER) enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, which converts HMG-CoA to mevalonate, catalyzes the ratelimiting step in cholesterol biosynthesis. Because this mevalonate pathway also produces several non-sterol isoprenoid compounds, the level of HMG-CoA reductase activity may coordinate many cellular processes and functions. We used gene targeting to knock out the mouse HMG-CoA reductase gene. The heterozygous mutant mice (Hmgcr+/-) appeared normal in their development and gross anatomy and were fertile. Although HMG-CoA reductase activities were reduced in Hmgcr+/- embryonic fibroblasts, the enzyme activities and cholesterol biosynthesis remained unaffected in the liver from Hmgcr+/- mice, suggesting that the haploid amount of Hmgcr gene is not rate-limiting in the hepatic cholesterol homeostasis. Consistently, plasma lipoprotein profiles were similar between Hmgcr+/- and Hmgcr+/+ mice. In contrast, the embryos homozygous for the Hmgcr mutant allele were recovered at the blastocyst stage, but not at E8.5, indicating that HMG-CoA reductase is crucial for early development of the mouse embryos. The lethal phenotype was not completely rescued by supplementing the dams with mevalonate. Although it has been postulated that a second, peroxisome-specific HMG-CoA reductase could substitute for the ER reductase in vitro, we speculate that the putative peroxisomal reductase gene, if existed, does not fully compensate for the lack of the ER enzyme at least in embryogenesis.

Study Type : Animal Study
Additional Links
Adverse Pharmacological Actions : Teratogenic : CK(323) : AC(65)

Print Options


Key Research Topics

This website is for information purposes only. By providing the information contained herein we are not diagnosing, treating, curing, mitigating, or preventing any type of disease or medical condition. Before beginning any type of natural, integrative or conventional treatment regimen, it is advisable to seek the advice of a licensed healthcare professional.

© Copyright 2008-2024 GreenMedInfo.com, Journal Articles copyright of original owners, MeSH copyright NLM.