Mitochondrial inorganic polyphosphate in the mammalian stress response.

摘要 线粒体功能障碍，包括生物能量学失调，已被广泛描述为细胞应激。 条件，如在许多人类疾病中发现的情况。然而，驱动线粒体 这些情况下的功能障碍和失败仍然知之甚少，无法实现有效的治疗靶向。 无机聚磷酸盐(Polyp)是一种普遍存在的分子，即使它在线粒体中显示出更好的位置。它是 在整个进化过程中都非常保守，它存在于每一个被研究的有机体中。息肉的纽带是 与在ATP中发现的能量相同，我们和其他人已经证明息肉是一种关键的能量代谢产物 (这项提议的科学前提)。Moroever，息肉在维持细胞内环境平衡中的关键作用 一些生物体，如细菌和酵母菌，其应激状态已为人所知。息肉的情况也是如此 参与一些关键的线粒体过程的调节，这些过程与生物能量学密切相关 哺乳动物细胞的状态，以及ii)参与应激反应。这些程序包括，对 线粒体钙稳态与线粒体通透性转换孔的形成和开放。 然而，息肉对哺乳动物细胞，更具体地说，线粒体的影响的确切程度 生理学；以及这些效应背后的分子机制仍然大多尚不清楚。这种分子 其机制可能涉及对肌醇多激酶(IPMK)/AMPK激活的蛋白激酶(AMPK)的调节。 Axis，这将把息肉作为哺乳动物生物能量学中的信号分子。这个项目的目标是 阐明线粒体息肉在线粒体生理学和细胞生物能量学中的作用 以及与疾病相关的压力状况。为了实现这一目标，根据参考书目和我们的初步数据， 我们的全球假设是：哺乳动物线粒体息肉是细胞生物能量学和 疾病相关急性应激条件下的线粒体生理学。息肉对线粒体的影响 生理作用也是通过调节IPMK/AMPK轴来实现的。为了验证这一假设，我们将使用哺乳动物 线粒体息肉水平将被修改的细胞模型，以及生化、细胞 生物学、分子生物学和组学技术。我们将首先优化检测哺乳动物息肉的方法(这是 这是这项提案创新的关键组成部分)。随后，我们将研究可能的监管效果。 息肉对细胞生物能量学和线粒体生理学以及息肉在生物能量学信号中的作用，通过 IPMK/AMPK轴的调节。这一应用与PI和实验室在线粒体方面的专业知识相一致 息肉和生物能量学，加快了他们的研究进展。此外，这也符合 PI在这一应用上的应用，这是为了解开导致人类线粒体功能障碍和衰竭的机制 疾病。所获得的数据不仅将增加我们对线粒体生理学的知识，还将帮助我们 建议将息肉作为一种新的、有前景的潜在药理工具，用于治疗各种病理条件 已经描述了生物能量学的失调(意义)。

ABSTRACT Mitochondrial dysfunction, including bioenergetics dysregulation, has been broadly described under cellular stress conditions, such as those found in many human diseases. However, the exact mechanisms that drive mitochondria to dysfunction and failure under these conditions are still too poorly understood to enable effective therapeutic targeting. Inorganic polyphosphate (polyP) is a ubiquitous molecule, even if it shows a preferred location within mitochondria. It is extremely well-conserved throughout evolution, and it is present in every studied organism. The bonds of polyP are isoenergetic to those found in ATP, and we and others have already demonstrated that polyP is a key energy metabolite (scientific premise for this proposal). Moroever, the key role played by polyP in maintaining cellular homeostasis under stress conditions in some organisms, such as bacteria and yeast, is already known. This is also the case for polyP’s involvement in the regulation of some crucial mitochondrial processes which are i) closely related to the bioenergetic status of mammalian cells, and ii) involved in the stress response. These processes include, the regulation of mitochondrial calcium homeostasis and the formation and opening of the mitochondrial permeability transition pore. Nonetheless, the exact extent of the effects of polyP in mammalian cellular, and more specifically, mitochondrial physiology; as well as the molecular mechanism underlying these effects still remain mostly unknown. This molecular mechanism could involve the regulation of the inositol multikinase (IPMK)/AMPK-Activated protein kinase (AMPK) axis, which will place polyP as a signaling molecule in mammalian bioenergetics. The objective of this project is to elucidate the mechanistic role of mitochondrial polyP in mitochondrial physiology and cellular bioenergetics, under basal and disease-relevant stress conditions. To accomplish this objective, based on the bibliography and our preliminary data, our global hypothesis is that: mammalian mitochondrial polyP is a key regulator of cellular bioenergetics and mitochondrial physiology under disease-relevant acute stress conditions. The effects of polyP on mitochondrial physiology are also exerted via the regulation of the IPMK/AMPK axis. To test this hypothesis, we will use mammalian cellular models in which the levels of mitochondrial polyP will be modified, and a combination of biochemical, cell biology, molecular biology, and -omics techniques. We will first optimize the methods to assay mammalian polyP (this is a crucial component of the innovation of this proposal). Subsequently, we will study the plausible regulatory effects of polyP on cellular bioenergetics and mitochondrial physiology, as well as polyP’s role in bioenergetics signaling, via the regulation of the IPMK/AMPK axis. This application aligns with the PI’s and laboratory’s expertise in mitochondrial polyP and bioenergetics, accelerating the progress of their research. Moreover, it is in line with the long-term goal of the PI on this application, which is to unravel the mechanisms that drive mitochondrial to dysfunction and failure in human disease. The obtained data will not only increase our knowledge of mitochondrial physiology, it will also help us to propose polyP as a new and promising potential pharmacological tool for various pathological conditions where the dysregulation of bioenergetics has been described (significance).