Age Effects on Liver Inflammation and Injury

年龄对肝脏炎症和损伤的影响

• 批准号: 7071795
• 负责人: Alex B. Lentsch
• 金额: $ 29.98万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7071795
• 关键词: Kupffer' s cell; SDS polyacrylamide gel electrophoresis; age difference; animal old age; apoptosis; cellular pathology; cytoprotection; enzyme linked immunosorbent assay; gel mobility shift assay; heat shock proteins; helper T lymphocyte; immunoprecipitation; infant animal; inflammation; ischemia; laboratory mouse; leukocyte activation /transformation; liver cells; liver disorder; nuclear factor kappa beta; oxidative stress; posttranslational modifications; proteomics; reperfusion; small interfering RNA; western blottings

DESCRIPTION (provided by the applicant): Hepatic injury is a primary cause of liver dysfunction in both pediatric and adult patients. Our preliminary studies using an established model of murine hepatic I/R indicate that mature mice (12-13 months of age) have significantly greater liver injury after I/R than do young mice (6-8 weeks of age). These findings are consistent with clinical studies of trauma patients which suggest that pediatric patients have a far lower incidence of multiple organ dysfunction syndrome than do adult patients. The long-term goal of this proposal is to determine the molecular and cellular mechanisms that differentiate young and mature mice in their response to hepatic I/R. Aim 1 will test the hypothesis that the transcription factor, NF-KB, is selectively depressed in hepatocytes of mature mice, leading to increased cell death and organ injury. We show that NF-KappaB activation is decreased in whole livers from mature mice, but that proinflammatory cytokine production is unaltered, suggesting that Kupffer cell activation of NF-KappaB is unaltered with age. Aim 2 will test the hypothesis that reduced hepatic expression of HSP70 in mature mice leads to increased oxidative tissue injury and hepatocyte cell death contributing to augmented I/R injury. We provide evidence that HSP70 protein expression is reduced in livers from mature mice and that this is associated with increased hepatocellular injury of both necrotic and apoptotic mechanisms. Aim 3 will test the hypothesis that CD4 lymphocytes serve to regulate hepatic I/R injury and that in mature mice altered function of CD4 lymphocytes contributes to augmented liver injury. Our preliminary data demonstrates that CD4-knockout mice have increased liver injury after I/R in a pattern that is identical to that observed in mature mice. We also show significant differences in the phenotypes of liver-resident lymphocytes between young and mature mice. Aim 4 will test the hypothesis that there are a number of cell-specific alterations in the proteomes of liver cells between young and mature mice and that these changes contribute to the divergent responses to I/R injury in these age populations. We will employ proteomics to determine the subcellular proteomes of Kupffer cells, hepatocytes, sinusoidal endothelial cells, and liver-resident lymphocytes before and after I/R to identify age-related alterations. These studies will advance our understanding of the age-dependent mechanisms that differentiate the hepatic inflammatory response of adult and pediatric patient populations to acute liver injury.

描述（由申请人提供）：肝损伤是儿童和成人患者肝功能障碍的主要原因。我们使用已建立的小鼠肝脏 I/R 模型进行的初步研究表明，成熟小鼠（12-13 月龄）在 I/R 后的肝损伤明显大于年轻小鼠（6-8 周龄）。这些发现与创伤患者的临床研究一致，这些研究表明儿童患者多器官功能障碍综合征的发生率远低于成人患者。该提案的长期目标是确定区分年轻和成熟小鼠对肝脏 I/R 反应的分子和细胞机制。目标 1 将检验以下假设：转录因子 NF-KB 在成熟小鼠的肝细胞中选择性抑制，导致细胞死亡和器官损伤增加。我们发现，成熟小鼠整个肝脏中 NF-KappaB 的激活减少，但促炎细胞因子的产生没有改变，这表明 NF-KappaB 的库普弗细胞激活不随年龄而改变。目标 2 将检验以下假设：成熟小鼠肝脏 HSP70 表达减少会导致氧化组织损伤和肝细胞死亡增加，从而加剧 I/R 损伤。我们提供的证据表明，成熟小鼠肝脏中 HSP70 蛋白表达降低，这与坏死和凋亡机制的肝细胞损伤增加有关。目标 3 将检验以下假设：CD4 淋巴细胞可调节肝 I/R 损伤，并且在成熟小鼠中，CD4 淋巴细胞功能的改变会导致肝损伤加剧。我们的初步数据表明，CD4 敲除小鼠在 I/R 后肝损伤增加，其模式与在成熟小鼠中观察到的相同。我们还发现年轻和成熟小鼠肝脏驻留淋巴细胞的表型存在显着差异。目标 4 将检验以下假设：年轻小鼠和成熟小鼠的肝细胞蛋白质组存在许多细胞特异性变化，这些变化导致这些年龄段小鼠对 I/R 损伤的不同反应。我们将采用蛋白质组学来确定 I/R 前后库普弗细胞、肝细胞、肝窦内皮细胞和肝脏驻留淋巴细胞的亚细胞蛋白质组，以识别与年龄相关的变化。这些研究将增进我们对年龄依赖性机制的理解，这些机制区分成人和儿童患者群体的肝脏炎症反应与急性肝损伤。