SMALL MOLECULE MODULATORS OF STATIN RESPONSE IN YEAST

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 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，HMG-CoA还原酶是固醇生物合成途径的第一步之一。在酿酒酵母中，用他汀类药物处理会导致生长减慢。通过用洛伐他汀结合不同代谢物的小库处理酵母，我们发现铜和锌离子降低了他汀类药物抑制生长的能力。我们分析了洛伐他汀和这两种金属处理后麦角甾醇及其前体化合物的基因表达和水平。他汀类药物单独处理诱导了固醇和细胞壁的生物合成基因，并降低了麦角固醇及其前体的水平。单独金属处理诱导了许多金属动态平衡基因，并上调了一组甾醇生物合成基因，导致显著增加了甾醇水平。药物和金属的结合协同上调了一些固醇生物合成基因，导致通过固醇生物合成途径的流量更大，并伴随着麦角固醇水平的增加。细胞对他汀类药物诱导的麦角固醇缺乏的反应是麦角固醇生物合成增加，而铜和锌可以增强这一反应。在培养的哺乳动物细胞中，这两种金属也挽救了他汀类生长抑制。因此，铜和锌的水平可能与人类的他汀类药物反应有关。代谢物扰动筛查，如本文所述，可以针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. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. 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.