Investigating the sex-specific roles of PKLR and CHCHD6 in insulin resistance and NAFLD

项目概要/摘要 非酒精性脂肪性肝病（NAFLD）越来越多地被认为是肝硬化的肝脏表现。 代谢综合征，可导致心血管疾病。目前，人们对遗传学知之甚少。 和NAFLD潜在的分子因素。此外，还没有已知的治疗策略可用于预防或治疗癌症。 治疗病情。为了解决这个问题，我们应用了一种综合的多组学方法， 表型分型小鼠队列，杂交小鼠多样性小组（HMDP），并确定了许多已知的和几个新的 调节NAFLD的候选基因。我们进一步验证了两个新的候选人，丙酮酸激酶，肝脏亚型 （PKLR）和含有卷曲螺旋卷曲螺旋螺旋结构域6（CHCHD 6）。当这两个基因 在脂肪变性的雄性小鼠模型中，NAFLD和胰岛素敏感性均得到改善，如通过 肝内甘油三酯蓄积水平、葡萄糖和胰岛素耐量试验、空腹血糖和 胰岛素水平后续的生物能量分析显示，这两个基因调节线粒体代谢， 出现脂肪变性和胰岛素抵抗当我们进一步扩展到包括女性HMDP菌株时， 我们发现这两个基因没有影响。具体而言，相关性分析显示PKLR和CHCHD 6 在雌性品系中分别不发生NAFLD和胰岛素抵抗。为了进一步了解 由这两个基因介导的基因与性别的相互作用在调节线粒体代谢和 发展NAFLD和胰岛素抵抗，我提出了三个相互关联的目标，以检查1）机制 潜在的PKLR和CHCHD 6介导的脂质代谢，2）肝脏特异性的代谢结果 脂肪变性雌性小鼠模型中的过表达或敲低，3）基因网络和细胞异质性 在晚期NASH和纤维化的小鼠模型中通过肝脏特异性过表达或敲低而改变。 此外，我还制定了详细的五年职业发展计划，其中包括两年 辅导阶段（K99阶段），然后是三年的独立阶段（R 00阶段），我过渡到一个 独立的学术生涯。我邀请了一个才华横溢的杰出顾问小组， Drs. Aldons J. Lusis，Orian Shirihai，Neil Kaplowitz，Andrea Hevener，Peter Tontonoz和Steven Bensinger， 帮助我过渡到独立。我在研究宿主遗传学和性别 使用系统遗传学分析，差异决定了复杂疾病特征的结果。我现在计划 扩大我在肝脏和线粒体生理学，脂质代谢，代谢表型和单细胞 测序总的来说，我的目标是提高我的训练，成为一名独立的调查员， 研究桥接系统遗传学、线粒体和肝脏代谢。

PROJECT SUMMARY/ABSTRACT Non-alcoholic fatty liver disease (NAFLD) is increasingly being recognized as the hepatic manifestation of metabolic syndrome that can lead to cardiovascular diseases. Currently, very little is known about the genetic and molecular factors underlying NAFLD. Besides, no known therapeutic strategies are available to prevent or treat the condition. To address this problem, we applied an integrative multi-omics approach using an extensively phenotyped mouse cohort, Hybrid Mouse Diversity Panel (HMDP) and identified many known and several novel candidate genes regulating NAFLD. We further validated two novel candidates, pyruvate kinase, liver isoform (PKLR) and coiled-coil-helix-coiled-coil-helix domain containing 6 (CHCHD6). When these two genes were knockdown in male mouse models of steatosis, both NAFLD and insulin sensitivity improved as measured by intrahepatic triglyceride accumulation levels, glucose- and insulin- tolerance tests, and fasting glucose and insulin levels. Follow-up bioenergetic analyses revealed these two genes regulated mitochondrial metabolism in developing steatosis and insulin resistance. When we further expanded this to include the female HMDP strains, we found that these two genes have no effect. Specifically, correlation analyses revealed PKLR and CHCHD6 do not develop NAFLD and insulin resistance in female strains, respectively. To further our understanding on the gene-by-sex interactions mediated by these two genes in regulating mitochondrial metabolism and in developing NAFLD and insulin resistance, I have proposed three interrelated aims to examine 1) mechanisms underlying PKLR- and CHCHD6- mediated lipid metabolism, 2) metabolic consequences of liver-specific overexpression or knockdown in female mouse models of steatosis, 3) gene networks and cellular heterogeneity altered by liver-specific overexpression or knockdown in mouse models of advanced NASH and fibrosis. Furthermore, I have developed a detailed five-year career development plan that includes two-year mentored phase (K99 phase) followed by three-year independent phase (R00 phase) for my transition into an independent academic career. I have included a highly talented and distinguished panel of advisors including Drs. Aldons J. Lusis, Orian Shirihai, Neil Kaplowitz, Andrea Hevener, Peter Tontonoz, and Steven Bensinger, to assist in my transition to independence. I have significant experience in studying how host genetics and sex differences dictate the outcomes of complex disease traits using systems genetics analyses. I now plan to expand my training in liver and mitochondrial physiology, lipid metabolism, metabolic phenotyping and single cell sequencing. Overall, the goal is to advance my training to become an independent investigator and perform research bridging systems genetics, mitochondria and liver metabolism.