Klotho Regulation and Aging

项目摘要 我们研究的重点是检查年龄抑制蛋白Klotho如何随着衰老而调节 在大脑中。当Klotho表达被消除时，小鼠发育正常，但衰老至4岁死亡。 月龄。这种快速恶化伴随着一种与观察到的表型相似的表型 在老年人中（认知障碍，动脉粥样硬化，异位钙化，肺气肿， 骨质疏松症、皮肤萎缩和脱发、胸腺退化、不孕症和骨矿物质减少 密度）。在小鼠中消除Klotho会导致认知障碍， 氧化应激相比之下，Klotho过表达转基因小鼠的寿命延长了30%，并且 抗氧化应激。我们的研究小组发现，Klotho在衰老的非人类细胞中表达下调， 灵长类动物、大鼠和小鼠的大脑，这些都让我们假设Klotho很重要， 脑功能及其随年龄的下调可能是氧化应激的结果，如果 预防，可以改善神经退行性疾病的衰退。建议的工作，检查 Klotho启动子和3'UTR随年龄的调节以及氧化损伤对 随着年龄的增长，Klotho启动子。我们将确定Klotho启动子的高GC含量是否 使其成为与年龄相关的下调目标，因为随着时间的推移， 因为氧化应激。这将通过比较Klotho的氧化状态来完成 在体外和老年恒河猴死后样品中， 个脑袋我们还将致力于表征结合和诱导激活的转录因子， Klotho启动子。Klotho启动子不包含经典的转录元件 入会仪式了解哪些因素对Klotho转录很重要可能有助于了解 导致Klotho活化的信号通路和Klotho在正常细胞中的作用。最后，我们将 确定Klotho是否受microRNA（miR）的调控，以及miR在大脑中的变化， 年龄miR结合并调节mRNA的翻译，但关于miR是否以及如何结合并调节mRNA的翻译， 影响Klotho处理。再次，了解调节Klotho的过程将使我们能够 更好地了解影响Klotho的过程以及Klotho在细胞中的更广泛作用。 功能这项工作的结果将为抗衰老基因Klotho和 阐明氧化损伤如何选择性下调特定基因的可能机制。

Project Abstract The focus of our study is to examine how the age suppressor protein, Klotho, is regulated with aging in the brain. When Klotho expression is eliminated, mice develop normally, but age to death by 4 months of age. This rapid deterioration is accompanied with a phenotype not unlike what is observed in aged humans (cognitive impairment, atherosclerosis, ectopic calcification, emphysema, osteoporosis, skin atrophy and hair loss, thymic involution, infertility and decreased bone mineral density). Elimination of Klotho in mice causes cognitive impairment that is associated with increased oxidative stress. In contrast, Klotho overexpressing transgenic mice live longer by up to 30% and are resistant to oxidative stress. Our group found that Klotho is downregulated in the aging non-human primate, rat and mouse brains Together, these have lead us to hypothesize that Klotho is important in brain function and its downregulation with age may be the result of oxidative stress which, if prevented, could ameliorate decline into neurodegenerative disease. The work proposed, examines regulation of the Klotho promoter and 3'UTR with age and the effect of oxidative damage to the Klotho promoter with age. We will determine whether the high GC content of the Klotho promoter makes it a target for age-related downregulation because of damage that accumulates over time because of oxidative stress. This will be done by comparing the oxidation state of the Klotho promoter to that of other genes both in vitro and in post mortem samples from aged rhesus monkey brain. We will also work to characterize the transcription factors that bind and induce activation of the Klotho promoter. The Klotho promoter does not contain the classical elements for transcription initiation. Understanding what factors are important for Klotho transcription may shed light on signaling pathways leading to Klotho activation and the role of Klotho in the normal cell. Last, we will determine whether Klotho is regulated by microRNAs (miR) and how miR change in the brain with age. MiR bind and regulate translation of mRNA and nothing is known about whether and how miR affect Klotho processing. Again, understanding the processes that regulate Klotho will enable us to have a better understanding of the processes that affect Klotho and Klotho's wider role in cellular function. The results of this work will add new knowledge on both the anti-aging gene Klotho and elucidate a possible mechanism for how oxidative damage selectively downregulates specific genes.