cerivastatin and mevalonolactone

Statins are the most widely used drugs for the treatment of hypercholesterolemia. In spite of their overall favorable safety profile, they do possess serious myotoxic potential, whose molecular origin has remained equivocal. Here, we demonstrate in cultivated myoblasts and skeletal muscle cells that cerivastatin at nanomolar concentrations interferes with selenoprotein synthesis and evokes a heightened vulnerability of the cells toward oxidative stressors. A correspondingly increased vulnerability was found with atorvastatin, albeit at higher concentrations than with cerivastatin. In selenium-saturated cells, cerivastatin caused a largely indiscriminate suppression of selenoprotein biosynthesis and reduced the steady state-levels of glutathione peroxidase 1 (GPx1) and selenoprotein N (SelN). Selenite, ebselen, and ubiquinone were unable to prevent the devitalizing effect of statin treatment, despite the fact that the cellular baseline resistance against tert-butyl hydroperoxide was significantly increased by picomolar sodium selenite. Mevalonic acid, in contrast, entirely prevented the statin-induced decrease in peroxide resistance. These results indicate that muscle cells may be particularly susceptible to a statin-induced suppression of essential antioxidant selenoproteins, which provides an explanation for the disposition of these drugs to evoke adverse muscular side-effects.

Topics: Animals; Atorvastatin; Cell Line; Cell Survival; Gene Expression Regulation; Heptanoic Acids; Hydrogen Peroxide; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Mevalonic Acid; Mice; Myoblasts; Oxidative Stress; Pyridines; Pyrroles; Rats; Selenium; Selenoproteins

High-dose statin treatment has been recommended as a primary strategy for aggressive reduction of LDL cholesterol levels and protection against coronary artery disease. The effectiveness of high-dose statins may be limited by their potential for myotoxic side effects. There is currently little known about the molecular mechanisms of statin-induced myotoxicity. Previously we showed that T-91485, an active metabolite of the squalene synthase inhibitor lapaquistat acetate (lapaquistat: a previous name is TAK-475), attenuated statin-induced cytotoxicity in human skeletal muscle cells [Nishimoto, T., Tozawa, R., Amano, Y., Wada, T., Imura, Y., Sugiyama, Y., 2003a. Comparing myotoxic effects of squalene synthase inhibitor, T-91485, and 3-hydroxy-3-methylglutaryl coenzyme A. Biochem. Pharmacol. 66, 2133-2139]. In the current study, we investigated the effects of lapaquistat administration on statin-induced myotoxicity in vivo. Guinea pigs were treated with either high-dose cerivastatin (1 mg/kg) or cerivastatin together with lapaquistat (30 mg/kg) for 14 days. Treatment with cerivastatin alone decreased plasma cholesterol levels by 45% and increased creatine kinase (CK) levels by more than 10-fold (a marker of myotoxicity). The plasma CK levels positively correlated with the severity of skeletal muscle lesions as assessed by histopathology. Co-administration of lapaquistat almost completely prevented the cerivastatin-induced myotoxicity. Administration of mevalonolactone (100 mg/kg b.i.d.) prevented the cerivastatin-induced myotoxicity, confirming that this effect is directly related to HMG-CoA reductase inhibition. These results strongly suggest that cerivastatin-induced myotoxicity is due to depletion of mevalonate derived isoprenoids. In addition, squalene synthase inhibition could potentially be used clinically to prevent statin-induced myopathy.

Topics: Animals; Biomarkers; Cholesterol; Creatine Kinase; Drug Antagonism; Drug Therapy, Combination; Enzyme Inhibitors; Farnesyl-Diphosphate Farnesyltransferase; Guinea Pigs; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Mevalonic Acid; Muscle, Skeletal; Muscular Diseases; Oxazepines; Piperidines; Pyridines

Neural apoptosis-regulated convertase (NARC)-1 is the newest member of the proprotein convertase family implicated in the cleavage of a variety of protein precursors. The NARC-1 gene, PCSK9, has been identified recently as the third locus implicated in autosomal dominant hypercholesterolemia (ADH). The 2 other known genes implicated in ADH encode the low-density lipoprotein receptor and apolipoprotein B. As an approach toward the elucidation of the physiological role(s) of NARC-1, we studied its transcriptional regulation.. Using quantitative RT-PCR, we assessed NARC-1 regulation under conditions known to regulate genes involved in cholesterol metabolism in HepG2 cells and in human primary hepatocytes. We found that NARC-1 expression was strongly induced by statins in a dose-dependent manner and that this induction was efficiently reversed by mevalonate. NARC-1 mRNA level was increased by cholesterol depletion but insensitive to liver X receptor activation. Human, mouse, and rat PCSK9 promoters contain 2 typical conserved motifs for cholesterol regulation: a sterol regulatory element (SRE) and an Sp1 site.. PCSK9 regulation is typical of that of the genes implicated in lipoprotein metabolism. In vivo, PCSK9 is probably a target of SRE-binding protein (SREBP)-2.

Topics: Alitretinoin; Animals; Atorvastatin; Base Sequence; Cell Line; Cholesterol; Consensus Sequence; DNA-Binding Proteins; Gene Expression Regulation; Hepatocytes; Heptanoic Acids; Homeostasis; Humans; Hydroxycholesterols; Hydroxymethylglutaryl CoA Reductases; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Liver X Receptors; Lovastatin; Mevalonic Acid; Mice; Orphan Nuclear Receptors; Promoter Regions, Genetic; Proprotein Convertase 9; Proprotein Convertases; Pyridines; Pyrroles; Quinolines; Rats; Receptors, Cytoplasmic and Nuclear; Regulatory Sequences, Nucleic Acid; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sequence Alignment; Sequence Homology, Nucleic Acid; Serine Endopeptidases; Simvastatin; Sp1 Transcription Factor; Species Specificity; Sterol Regulatory Element Binding Protein 2; Transcription Factors; Tretinoin