Inflammation-Gene Expression by Monocytes in Frailty

描述(由申请人提供)：与非虚弱的老年人相比，虚弱的老年人功能衰退、跌倒、住院、养老院安置和早期死亡的风险更高。新出现的证据表明，以CRP和IL-6水平升高为标志的炎症与虚弱有关。然而，人们对虚弱老年人炎症系统激活的范围和潜在机制知之甚少。单核细胞在局部和全身炎症的激活和调节中起着关键作用，研究编码细胞因子介质和受体的基因在单核细胞中的表达有助于深入了解脆弱时炎症系统激活的分子机制。这项建议的短期目标是为虚弱老年人分离的单核细胞炎症特异性基因表达的特定调控建立初步的初步数据。该项目的长期目标是利用这些发现来开发更深入的脆弱病因和干预研究。我们假设虚弱的老年人在编码IL-6、TNF-α、IL-1β和IL-1受体拮抗剂(IL-1ra)的基因的结构性和内毒素诱导的单核细胞表达方面有显著的变化。这项建议的主要目的是验证这一假说，并进一步探索在虚弱综合征中对编码80个其他细胞因子介质和细胞表面分子的基因的结构性和内毒素诱导的单核细胞表达进行调节的初步证据。为了实现这些目标，我们建议对社区居住的虚弱和非虚弱老年人中编码84个细胞因子介质和细胞表面分子的基因的结构性和内毒素诱导的单核细胞表达进行探索性调查(R21)。一种经过验证的脆弱筛查工具将用于识别15对年龄、种族和性别匹配的脆弱和非脆弱老年人。单核细胞将在有无内毒素的情况下分离和培养。我们将使用一种商业上可用的炎症特异性基因阵列，评估和比较虚弱和非虚弱受试者的构成基因和内毒素诱导的单核细胞基因的表达，该基因阵列包含IL-6、肿瘤坏死因子-α、IL-1β、IL-1ra和80种其他细胞因子介质和细胞表面分子的cDNA。有显著差异的候选基因将通过定量RT-PCR进行进一步评估。对编码IL-6、TNF-α、IL-1β、IL-1ra的基因的结构性和内毒素诱导的单核细胞表达的初步评估，将为在虚弱的老年人中更明确地研究单核细胞的产生和这些重要细胞因子介质的调节奠定基础。该项目还将探索在虚弱的老年人中，编码80个其他细胞因子介质和细胞表面分子的基因的结构性和内毒素诱导的单核细胞表达的调节的初步证据。因此，它将作为一个假说生成项目，并作为假说完善的基础，这将为未来对老年脆弱的机械性和潜在的干预性调查开辟新的途径。

DESCRIPTION(provided by applicant): Frail older adults are at increased risk for functional decline, falls, hospitalization, nursing home placement, and early mortality as compared to non-frail older adults. Emerging evidence suggests that inflammation, as marked by elevated levels of CRP and IL-6, is associated with frailty. However, little is known about the scope of, and the underlying mechanisms that contribute to, the activation of the inflammation system in frail older adults. Monocytes play pivotal roles in the activation and regulation of local and systemic inflammation, and investigating monocytic expression of genes encoding cytokine mediators and receptors can provide considerable insight into molecular mechanisms that underlie activation of the inflammation system in frailty. The short-term goal of this proposal is to establish initial preliminary data for specific modulations in inflammation-specific gene expression of isolated monocytes from frail older adults. The long-term goal of this project is to utilize these findings for the development of more in-depth etiologic and interventional studies of frailty. We hypothesize that frail older adults have significant alterations in constitutive and LPS-induced monocytic expression of genes encoding IL-6, TNF-alpha, IL-1beta, and IL-1 receptor antagonist (IL-1ra). The primary objectives of this proposal are to test this hypothesis and to further explore initial evidence for modulations in constitutive and LPS-induced monocytic expression of genes encoding 80 other cytokine mediators and cell surface molecules in the frailty syndrome. To accomplish these objectives, we propose an exploratory investigation (R21) into constitutive and LPS-induced monocytic expression of genes encoding 84 cytokine mediators and cell surface molecules in community-dwelling frail and non-frail older adults. A validated frailty-screening tool will be used to identify 15 age-, race-, and sex-matched pairs of frail and nonfrail older adults. Monocytes will be isolated and cultured in the presence and absence of LPS. Constitutive and LPS-induced monocytic gene expression will be evaluated and compared between frail and non-frail subjects, using a commercially available, inflammation-specific gene array containing cDNAs of IL-6, TNF-alpha, IL-1beta, IL-1ra, and 80 other cytokine mediators and cell surface molecules. Candidate genes with significant differences will be further evaluated by quantitative RT-PCR. This initial evaluation of the constitutive and LPS-induced monocytic expression of genes encoding IL-6, TNF-alpha, IL-1beta, IL-1ra will set the stage for more discerning mechanistic studies on monocytic production and regulation of these important cytokine mediators in frail older adults. This project will also explore initial evidence for modulations in constitutive and LPS-induced monocytic expression of genes encoding 80 other cytokine mediators and cell surface molecules in frail older adults. Therefore, It will serve as a hypothesis-generating project, and a basis for hypothesis refinement, that will open new pathways for future mechanistic and, potentially, interventional investigations of frailty in old age.