Bipartite regulation of cellular osmosensing in C. elegans

C.细胞膜感受的双向调节。elegans 维持细胞溶质和水含量的生理过程称为渗透稳态，或 它是一种重要的调节机制，对所有形式的细胞生命都是必不可少的。在人类中，渗透平衡起着至关重要的作用， 在几种情况下，包括调节肾脏的尿浓缩机制，控制血液 压力和免疫反应的激活。渗透压平衡失调与几个年龄段有关- 相关疾病，包括慢性肾病、肾衰竭、高血压和周围神经病变。 尽管在生理和病理生理疾病状态中，β-内酰胺酶调节的重要性显而易见， 关于动物细胞感知和响应渗透压的机制知之甚少。更好的 了解这些机制可能有助于早期发现和干预与年龄有关的疾病。 大多数关于细胞调节的研究都是使用培养的细胞进行的，这些细胞不能模拟这种复合物。 这些研究已经导致了许多假设来解释大多数细胞被发现的环境。 - 细胞膜感测的机制，例如膜和/或细胞骨架的机械“拉伸”， 大分子拥挤和细胞质离子含量的改变。然而， 支持这些模型的数据。为了获得对细胞凋亡敏感机制的体内观点， 在动物中，我们正在模式生物C中研究这一过程。elegans，其中复杂的细胞-细胞和细胞- 细胞外基质（ECM）相互作用得以保留。使用无偏正向和反向遗传算法 通过这些方法，我们发现了细胞外基质的关键作用（Rohlfing等人，PLoS Genetics，2011）， 蛋白质错误折叠（Moronetti Mazzeo等，PNAS，2012）在C. 优雅基于这些发现，我们假设动物细胞同时使用机械传导和蛋白质 损伤检测机制，以感知渗透干扰并激活渗透敏感性基因表达。 在目标1中，我们将确定C.线虫表皮细胞外基质作为一种结构性的“生物传感器”， 通过粘蛋白样蛋白质OSM-8和跨膜蛋白质PTR-23之间的相互作用来传递信息。在 目的2，我们将确定天然蛋白质易受胁迫诱导的蛋白质聚集，并确定如何 衰老和衰老调节剂对渗透胁迫诱导的蛋白质损伤和衰老敏感基因的影响 表情在目标3中，我们将研究ECM和蛋白质损伤检测途径如何相互作用， 另一种是控制神经调节生理学。我们的研究最大限度地利用了C。elegans系统 填补了我们对后生动物细胞生理学知识的重要空白。这些发现将提供变革性的 深入了解保守的过程中的免疫调节，这将使我们能够更好地了解，检测， 管理与年龄相关的渗透性平衡失调疾病。

Bipartite regulation of cellular osmosensing in C. elegans The physiological process of maintaining cellular solute and water content is termed osmotic homeostasis, or osmoregulation, and is essential for all forms of cellular life. In humans, osmotic homeostasis plays vital roles in several contexts, including regulation of the kidney's urinary concentrating mechanism, control of blood pressure, and activation of immune responses. Osmotic dyshomeostasis is associated with several age- related diseases, including chronic kidney disease, renal failure, hypertension, and peripheral neuropathy. Despite the obvious importance of osmoregulation in both physiological and pathophysiological disease states, little is known about the mechanisms by which animal cells sense and respond to osmotic stress. A better understanding of these mechanisms may allow earlier detection and intervention in age-related diseases. Most studies of osmoregulation have been carried out using cultured cells, which fail to mimic the complex environments in which most cells are found. These studies have led to many hypotheses to explain the mechanism(s) of cellular osmosensing, such as mechanical 'stretching' of the membrane and/or cytoskeleton, macromolecular crowding, and alterations in cytoplasmic ionic content, to name a few. However, there is little data supporting any of these models. To gain an in vivo perspective on mechanisms of cellular osmosensing in animals, we are studying this process in the model organism C. elegans, in which complex cell-cell and cell- extracellular matrix (ECM) interactions are preserved. Using unbiased forward and reverse genetic approaches, we discovered critical roles for the extracellular matrix (Rohlfing et al, PLoS Genetics, 2011) and protein misfolding (Moronetti Mazzeo et al, PNAS, 2012) in the regulation of cellular osmosensing in C. elegans. Based on these findings we hypothesize that animal cells use both mechanotransduction and protein damage detection mechanisms to sense osmotic disturbances and activate osmosensitive gene expression. In Aim 1, we will determine if the C. elegans cuticular ECM acts as a structural 'osmosensor' to transduce information via interactions between the mucin-like protein OSM-8 and a transmembrane protein PTR-23. In Aim 2, we will define the native proteins susceptible to stress-induced protein aggregation and determine how aging and aging regulators influence osmotic stress induced protein damage and osmosensitive gene expression. In Aim 3, we will examine how ECM and protein damage detection pathways interact with each other to control osmoregulatory physiology. Our studies take maximal advantage of the C. elegans system to fill an important gap in our knowledge of metazoan cell physiology. These findings will provide transformative insights into the conserved process of osmoregulation that will allow us to better understand, detect, and manage age-related diseases of osmotic dyshomeostasis.