Statin Increases GTP Cyclohydrolase I mRNA and 5,6,7,8-Tetrahydrobiopterin in Vascular Endothelial Cells

Autor: Hattori Yoshiyuki, Nakanishi Nobuo
Jazyk: angličtina
Rok vydání: 2006
Předmět:
Zdroj: Pteridines, Vol 17, Iss 3, Pp 65-68 (2006)
Druh dokumentu: article
ISSN: 0933-4807
2195-4720
DOI: 10.1515/pteridines.2006.17.3.65
Popis: We investigated the effects of HMG-CoA reductase inhibitors, so-called statins, on 5,6,7,8-tctrahydrobioptcrin (BH4) metabolism in human umbilical vein endothelial cells (HUVEC). The mRNA of GTP cyclohydrolase I (GTPCH), as well as cNOS, was upregulated in HUVEC treated with cerivastatin. This increase was time- and dose-dependent. Fluvastatin was also observed to enhance GTPCH and eNOS mRNA levels. In parallel with this observation, cerivastatin increased intracellular BH4. Cerivastatin increased the stability of eNOS mRNA. However, it did not alter the stability of GTPCH mRNA but increased GTPCH gene transcription as shown by nuclear run-on assays. Preteatment of HUVEC with the selective GTPCH inhibitor, 2,4-diamino-6-hydroxypyrimidine, caused a decrease in intracellular BH4 and decreased citrulline formation following stimulation with ionomycin. Furthermore, the potentiating effect of cerivasatin was decreased by limiting the cellular availability of BH4. In addition to augmenting eNOS expression, statins potentiate GTPCH gene expression and BH4 synthesis, thereby increasing NO production and preventing relative shortages of BH4
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