SMALL MOLECULE MODULATORS OF STATIN RESPONSE IN YEAST

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 我们建立了一个基于酵母的筛选，以探索内源性代谢物如何与降胆固醇药物洛伐他汀相互作用。 洛伐他汀和其他他汀类药物抑制HMG-CoA还原酶，该还原酶是固醇生物合成途径中的第一步。 在酵母酿酒酵母中，用他汀类药物处理导致生长减少。 通过用洛伐他汀与不同代谢物的小文库组合处理酵母，我们发现铜和锌离子降低了他汀类药物抑制生长的能力。 我们分析了基因表达和麦角固醇及其前体化合物的水平与洛伐他汀和这些金属治疗后。 他汀类药物单独治疗诱导甾醇和细胞壁生物合成基因，并降低麦角甾醇及其前体的水平。 金属处理单独诱导许多金属稳态基因和上调一个子集的甾醇生物合成基因，导致显着增加甾醇水平。 药物加金属的组合协同上调一些固醇生物合成基因，导致通过固醇生物合成途径的更大通量和麦角固醇水平的伴随增加。 细胞对他汀类药物诱导的麦角固醇剥夺有反应，麦角固醇生物合成增加，铜和锌可以增强这种反应。 在培养的哺乳动物细胞中，这两种金属也挽救了他汀类药物的生长抑制。 因此，铜和锌水平可能与人类的他汀类药物反应相关。 代谢物扰动屏幕，如这里提出的一个可以对几乎任何酵母表型进行，因此适用于广泛的问题。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. We established a yeast-based screen to explore how endogenous metabolites interact with lovastatin, a cholesterol-lowering drug. Lovastatin and other statins inhibit HMG-CoA reductase, which carries out one of the first steps in the sterol biosynthesis pathway. In the yeast Saccharomyces cerevisiae, treatment with a statin results in reduced growth. By treating yeast with lovastatin in combination with a small library of diverse metabolites, we found that copper and zinc ions reduced the ability of the statin to inhibit growth. We analyzed both gene expression and levels of ergosterol and its precursor compounds after treatment with both lovastatin and either of these metals. Statin treatment alone induced sterol and cell wall biosynthesis genes and decreased the levels of ergosterol and its precursors. Metal treatment alone induced many metal homeostasis genes and upregulated a subset of sterol biosynthesis genes, resulting in significantly increased sterol levels. The combination of the drug plus metal synergistically upregulated some sterol biosynthesis genes, resulting in greater flux through the sterol biosynthesis pathway and a concomitant increase in ergosterol levels. The cell responds to the ergosterol deprivation induced by a statin with an increase in ergosterol biosynthesis, and copper and zinc can enhance this response. In cultured mammalian cells, these two metals also rescued statin growth inhibition. Thus, copper and zinc levels could have relevance to statin response in humans. Metabolite perturbation screens such as the one presented here can be performed against nearly any yeast phenotype, and therefore are applicable to a wide range of problems.