Urinary peptide excretion and onset of puberty

描述(由申请人提供)： 该项目的短期目标是利用蛋白质组学方法来确定青春期开始的时间和阶段。这项研究将利用之前在NCI资助的U54观察性研究中从10-13岁女孩身上收集的尿样和血液样本。样本取自月经初潮前的女孩，在研究开始时，以及随后的12个月和24个月。在每个时间点进行饮食问卷调查。每月进行问卷调查和电话访谈，以评估青春期的发展。这项研究的长期目标是更好地了解青春期发生的生化和生理事件，因为一项对基因同卵双胞胎的研究强烈表明，青春期的开始是由外部环境影响控制的，而不是遗传因素。此外，研究发现，青春期开始越早，成年患乳腺癌的风险就越高。假说是，青春期导致类固醇敏感基因的表达发生显著变化，从而导致其产物蛋白质的变化。由于大多数细胞的寿命相对较短(几天到几周)，它们中的蛋白质会发生周转，并在血液中以多肽的形式出现。此外，由于青春期身体的大规模再分布，非雌激素敏感组织中蛋白质中的多肽也会发生重大变化。虽然尿液中含有一些完整的蛋白质，但经肾小球过滤后，大部分可检测到的多肽都在20 kDa以下。在这项研究中，我们将(1)首先使用MALDI-TOF MS建立月经前和月经后食用低大豆饮食的高加索女孩之间统计上不同的潜在多肽，然后使用NanoLC-MALDI和串联MS鉴定多肽的来源，最后建立NanoLC-MRM-Tandem MS方法来定量分析青春期相关多肽；(2)使用所建立的程序，评估年龄、月经初潮前或初潮以来以及种族/民族是否影响这些标志物；利用纵向收集的个别女孩青春期的标本来验证这些标记，同时考虑到年龄、月经初潮前后的时间或这一目标中确定的种族/族裔的任何差异；以及(3)确定高大豆饮食是否影响青春期发育，使用这些多肽标记来衡量，同时考虑到各种因素的任何混淆，并确定这些多肽标记的水平是否因月经前期和经期初潮后女孩的大豆摄入量而有所不同。 项目简介：这项研究的目标是通过应用现代蛋白质组学方法来确定从高加索和亚洲女孩队列中收集的月经初潮开始前后尿液中的多肽，从而确定青春期开始的阶段。纵向研究将使研究人员能够区分与青春期本身不同的与年龄相关的变化。还将检查饮食中大豆异黄酮类的摄入量和种族/民族对肽标记物的影响。

DESCRIPTION (provided by applicant): The short-term goal of this project is to utilize a proteomics approach to define the timing and stages of the onset of puberty. The study will utilize urine and blood samples collected previously from girls between the ages of 10-13 in an NCI-funded U54 observational study. Specimens were obtained from pre-menarcheal girls at study entry and at the following 12 and 24 months. Dietary questionnaires were taken at each time-point. Monthly questionnaires and telephone interviews were performed to assess the development of puberty. The long-term goal of this study is to better understand the biochemical and physiological events that occur during puberty since a study in genetically identical twins strongly suggested that the onset of puberty was controlled by external environmental effects, not genetic factors. In addition, the study found that earlier the onset of puberty, the higher the adult risk of breast cancer. The hypothesis is that puberty causes marked changes in the expression of steroid-sensitive genes and hence their products, the proteins. Since most cell lifetimes are relatively short (days-weeks), the proteins in them are subjected to turnover and will appear in blood as peptides. In addition, because of the large-scale redistribution of the body during puberty, peptides from proteins in non-estrogen sensitive tissues will also undergo significant changes. Although urine contains some intact proteins, filtration by kidney glomeruli results in the bulk of detectable peptides being below 20 kDa. The peptides will be recovered from urine using a high throughput hydrophobic cartridge and then eluted to yield a predominantly peptide fractionIn this study, we will (1) first use MALDI-TOF MS to establish potential peptides which statistically differ between pre-menarcheal and post-menarcheal Caucasian girls consuming a low soy diet, then use nanoLC-MALDI and tandem MS to identify the proteins from which the peptides were derived, and finally develop nanoLC-MRM-tandem MS methods to quantitatively assay the puberty-associated peptides; (2) using the established procedure, to evaluate whether age, time to or since menarche, and race/ethnicity impact these markers; to validate these markers using longitudinally collected specimens on individual girls going through puberty, taking into account any differences by age, time to or since menarche, or race/ethnicity identified in this aim; and (3) to determine if a high soy diet impacts pubertal development, as measured using these peptide markers, taking into account any confounding by the factors, and to determine if the levels of these peptide markers differ by level of soy consumption in pre-menarcheal and post-menarcheal girls. Project Narrative: The goal of this study is to define the stages of onset of puberty by applying modern proteomics methods to identify peptides in urines collected before and after the onset of menarche from a cohort of Caucasian and Asian girls. Longitudinal studies will allow the investigators to distinguish age-related change changes that are distinct from puberty itself. The effects of dietary intake of soy isoflavones and of race/ethnicity on the peptide markers will also be examined.