The Role of Mitochondrial TNAP in Adaptive Thermogenesis

摘要 生热脂肪细胞和适应性生热是治疗和治疗癌症的有前景的治疗靶点。 预防肥胖和肥胖相关糖尿病。我们最近证明了线粒体组织- 非特异性碱性磷酸酶(TnAP)在无用肌酸循环(FCC)和适应性调节中起重要作用 磷酸肌酸的水解生热作用。TnAP在小鼠体内的药理抑制或基因消融 减少系统能量消耗。基因消融小鼠的TNAP也会导致快速发病的肥胖。TNAP 假定线粒体定位于产热脂肪细胞，这可能确保细胞- 磷酸肌酸水解事件和催化裂化操作的选择性。在这里，我们建议研究 TNAP在小鼠脂肪组织中的功能增强代谢效应及其分子机制 以及对其线粒体定位的调控。使用人工表达TNAP的转基因小鼠品系 在脂肪组织中，我们将研究其对肥胖、糖尿病、脂肪肝和能量消耗的影响。至 研究TNAP的定位，我们将检验其细胞特异性是否在于TNAP多肽或其转运 路径，或者两者都有。我会先确定是否有任何分子元素(例如，PTMS或氨基酸 序列)对其线粒体定位至关重要。这将使用 生物化学和细胞成像方法的结合。此外，我们还将研究细胞途径。 转移到线粒体的TNAP。我们将询问脂筏在TNAP定位中的作用。这可能会允许 美国确定TNAP线粒体本地化的关键调节因子和介体。最后，我们将确定 其他与TNAP定位途径相同的线粒体蛋白，并研究其功能。 候选人孙毅智博士在以分子为重点的创新研究方面有着良好的记录 疾病的机制。候选人的职业目标是成为一名独立的学术调查员， 旨在了解和逆转肥胖及其相关代谢的研究实验室 精神错乱。拟议的研究将在达纳-法伯大学博士布鲁斯·斯皮格尔曼的实验室进行。 他是分子代谢和脂肪细胞领域的领先者 生物学。拟议的研究还将汇集咨询委员会的主要实验室，这些实验室 在细胞成像、蛋白质运输和线粒体生物学方面的专业知识。所有这些，连同理想 朗伍德医疗领域的研究环境，将最大限度地发挥申请者的潜力，使其成功 过渡到一个独立的调查员。

Abstract Thermogenic adipocytes and adaptive thermogenesis are promising therapeutic targets for treating and preventing obesity and obesity-linked diabetes. We recently demonstrated that the mitochondrial tissue- nonspecific alkaline phosphatase, TNAP, plays a crucial role in the futile creatine cycle (FCC) and adaptive thermogenesis by hydrolyzing phosphocreatine. Pharmacological inhibition or genetic ablation of TNAP in mice reduces systemic energy expenditure. Genetic ablation of TNAP in mice also causes rapid-onset obesity. TNAP assumes a mitochondrial localization specifically in thermogenic adipocytes, which might ensure the cell- selectivity of the phosphocreatine hydrolysis events and the FCC operation. Here, we propose to study the metabolic effects of gain-of- function of TNAP in the adipose tissues in mice, as well as the molecular mechanism and regulation of its mitochondrial localization. Using a transgenic mouse strain that artificially expresses TNAP in the adipose tissues, we will investigate its effects on obesity, diabetes, fatty liver, and energy expenditure. To study the TNAP localization, we will test whether its cell specificity lies in the TNAP polypeptide or its trafficking pathway, or both. I will first determine whether there are any molecular elements (e.g., PTMs or amino acid sequences) on the TNAP polypeptide crucial for its mitochondrial localization. This will be done using a combination of biochemical and cell imaging approaches. In addition, we will investigate the cellular pathway of TNAP trafficking to mitochondria. We will interrogate the role of lipid rafts in TNAP localization. This might allow us to identify key regulators and mediators of the mitochondrial localization of TNAP. Finally, we will identify other mitochondrial proteins that share the localization pathway of TNAP and study their functions. The candidate, Dr. Yizhi Sun, has a strong track record of innovative research with a focus on the molecular mechanisms of diseases. The candidate’s career goal is to become an independent academic investigator with a research laboratory oriented towards understanding and reversing obesity and obesity-linked metabolic disorders. The proposed research will be conducted in the laboratory of Bruce Spiegelman, PhD at Dana-Farber Cancer Institute and Harvard Medical School, who is a leader in the fields of molecular metabolism and adipocyte biology. The proposed studies will also bring together leading laboratories of the advisory committee that have expertise in cell imaging, protein trafficking, and mitochondrial biology. All of these, together with the ideal research environment in the Longwood Medical Area, will maximize applicant’s potential to successfully transition to an independent investigator.