Identification of Splicing-Related Aging Biomarkers

描述(由申请人提供)：细胞衰老是一个强大的体外模型，用于探索生物衰老的分子机制。一种流行的假设是，当端粒缩短到临界点以下时，它就像一个有丝分裂钟，决定了细胞周期的永久退出。除了端粒缩短外，某些癌基因或环境刺激(如γ辐射)也可提前引发细胞衰老。另有报道称，层蛋白A基因(lamin A，LMNA)第11外显子的从头突变导致层蛋白A(lamin A，LMNA)前信使核糖核酸的异常剪接导致HGPS患者细胞过早衰老和加速衰老。有趣的是，HGPS中层蛋白A的异常剪接产物(称为孕激素)随着年龄的变化在健康人的细胞和组织中积累，这表明mRNA剪接的变化不一定与突变有关，也可能受到年龄相关因素的影响。与这一思路一致的是，其他一些基因，包括细胞黏附分子纤维连接蛋白和中间丝蛋白波形蛋白，在正常衰老细胞中被交替剪接。这一想法也在与衰老相关的神经退行性疾病中得到了例证，如阿尔茨海默氏症、帕金森氏病和tauopathy，所有这些疾病都涉及前mRNAs剪接中的异常。基于上述发现，我们假设在细胞衰老过程中存在选择性剪接的广泛变化。其中一些与衰老相关的亚型可能是衰老细胞所特有的，对细胞建立衰老状态具有重要的功能，可以进一步开发成为新的衰老生物标志物。为了解决这一假设，我们将进行一系列调查，包括确定 使用RNA-seq(Aim1)剪接培养的衰老细胞的变化，在体外和体内表征这些与衰老相关的亚型，以将它们发展为衰老生物标记物(AIM2)。

DESCRIPTION (provided by applicant): Cellular aging is a powerful in vitro model for exploring molecular mechanisms underlying organismal aging. A popular hypothesis is that, when the telomeres shorten to below a critical point, it acts as a mitotic clock dictating the permanent exit from the cell cycle. Besides telomere shortening, cellular senescence can be triggered prematurely by certain oncogenes or environmental stimuli, such as γ-irradiation. It has also been reported that an aberrant splicing of the pre-mRNA of the lamin A gene (LMNA), due to a de novo mutation in the exon 11, leads to premature cellular senescence and accelerated aging in patients with Hutchinson-Gilford progeria syndrome (HGPS). Interestingly, a small amount of the aberrant splicing product of lamin A in HGPS (named "progerin") accumulates in the cells and tissues of healthy individuals as a function of age, suggesting that alterations in mRNA splicing are not necessarily associated with mutations and may also be influenced by age-related factors. Consistent with this line of thinking, a few other genes, including a cell adhesion molecule fibronectin and an intermediate filament protein vimentin, are alternatively spliced in normal senescent cells. This idea is also exemplified in aging-related neurodegenerative diseases, such as Alzheimer's, Parkinson's diseases and tauopathies, all involving aberrations in pre-mRNAs splicing. Based on the above findings, we hypothesize that there are widespread changes in alternative splicing during cellular senescence. Some of these senescence-related isoforms may be unique to senescent cells and functionally important for cells to establishing senescence state, which can be further developed into novel biomarkers for aging. To address this hypothesis, we will conduct a series of investigations including identifying splicing changes in cultured senescent cells using RNA-seq (Aim1), characterizing these senescence-associated isoforms in vitro and in vivo to develop them into aging biomarkers (Aim2).