Relationship of candidate circulating proteoforms with aging phenotypes.

 描述(申请人提供)：最近的动物研究已经确定了几种可以逆转或加速衰老表型的多肽或蛋白质。这些候选基因包括生长/分化因子11(GDF11)、生长/分化因子8(GDF8)、催产素、嗜酸性粒细胞趋化因子以及GDF11和GDF8的抑制物：GDF11和GDF8前肽、卵泡抑素、卵泡抑素相关蛋白3(FSTR3)、WFIKKN1和WFIKKN2。这些候选多肽或蛋白质很难用传统的免疫分析方法在血液中进行研究，因为一些多肽或蛋白质以多种异构体存在，经历了切割或末端降解，或者彼此具有很高的序列同源性。这些蛋白形式(定义为可在其中找到单个基因的蛋白质产物的不同分子形式，如异构体、裂解和降解产物)是否与人类的衰老表型具有类似的关系尚不清楚。我们将使用一种新的多重选择反应监测(SRM)和LC-MS/MS(LC-MS/MS)来检测15种血浆蛋白质组分，它们代表了复壮研究中的八种重要蛋白质。我们将测试这些候选蛋白形式的血浆浓度随年龄变化的假设，并在超过实际年龄的情况下，预测成年人特定衰老表型的发展。具体目标是：(1)最终建立用于血浆蛋白形式绝对定量的LC-MS/MS分析方法：GDF11(前肽，成熟蛋白)，GDF8(前肽，成熟蛋白)，卵泡抑素(2个异构体，1个裂解形式)，FSTR3，WFIKKN1，WFIKKN2，Eoaxin，催产素(2个羧基扩展形式)及其载体蛋白，NeuroPhyin-1，(2)在Baltimore老龄化纵向研究和复制队列InCHIANTI研究中表征循环候选蛋白形式与衰老表型的关系。衰老表型包括普遍和偶发的骨质疏松症、下肢体能、残疾、认知、记忆力、心肌肥厚和胰岛素抵抗。到项目结束时，我们应该能够验证或驳斥这些候选蛋白形式在人类衰老表型中的作用。

 DESCRIPTION (provided by applicant): Recent animal studies have identified several polypeptides or proteins that can reverse or accelerate aging phenotypes. These candidates include growth/differentiation factor 11 (GDF11), growth/differentiation factor 8 (GDF8), oxytocin, eotaxin, and inhibitors of GDF11 and GDF8: GDF11 and GDF8 propeptides, follistatin, follistatin-related protein 3 (FSTR3), WFIKKN1, and WFIKKN2. These candidate polypeptides or proteins have been difficult to study in the blood using conventional immunoassays, since some of the peptides or proteins exist in multiple isoforms, undergo cleavage or terminal degradation, or have high sequence identity with each other. Whether these proteoforms (defined as the different molecular forms in which the protein product of a single gene can be found, such as isoforms, cleavage, and degradation products) have a similar relationship to aging phenotypes in humans is not known. We will use a novel multiplexed selected reaction monitoring (SRM) assay and liquid chromatography-tandem mass spectrometry (LC-MS/MS) to measure fifteen plasma proteoforms representing eight important proteins in rejuvenation research. We will test the hypothesis that plasma concentrations of these candidate proteoforms change with aging, and, beyond chronological age, predict the development of specific aging phenotypes in adults. The specific aims are: (1) to finalize development of the SRM assay using LC-MS/MS for absolute quantification of plasma proteoforms: GDF11 (propeptide, mature protein), GDF8 (propeptide, mature protein), follistatin (2 isoforms, 1 cleaved form), FSTR3, WFIKKN1, WFIKKN2, eotaxin, oxytocin (nonapeptide, 2 carboxyl-extended forms) and its carrier protein, neurophysin-1, (2) to characterize the relationship of circulating candidate proteoforms with aging phenotypes in the Baltimore Longitudinal Study of Aging and in a replication cohort, the InCHIANTI Study. Aging phenotypes include prevalent and incident sarcopenia, lower extremity physical performance, disability, cognition, memory, cardiac hypertrophy, and insulin resistance. By the end of the project, we should be able to verify or refute the role of these candidate proteoforms in phenotypes of human aging.