ALCOHOL'S EFFECTS ON THE DEVELOPING ALVEOLAR MACROPHAGE

描述（由申请人提供）：由于包括肺泡巨噬细胞（AM）在内的炎症细胞不成熟，早产儿肺部感染的风险增加。 AM 是抵抗肺部感染的第一道防线。 谷胱甘肽 (GSH) 是肺部的一种主要抗氧化剂，AM 需要它来维持氧化还原电位并优化细胞内功能。 早产儿的全身和肺泡谷胱甘肽水平不足，使肺部面临氧化损伤和细胞功能障碍的风险增加。成人长期接触酒精 (ETOH) 还会增加全身氧化应激并损害 AM 的免疫功能。 育龄妇女的 ETOH 消费量显着增加，仍然是我们社会的一个重大健康问题。 子宫内暴露于 ETOH 的胎儿面临全身氧化应激的风险，全身和肝脏 GSH 减少以及活性氧标记物增加就证明了这一点。 我们推测，当与氧化应激（例如子宫内 ETOH 暴露引起的氧化应激）叠加时，早产引起的肺部 GSH 缺乏会加剧。 肺部 GSH 减少会降低常驻 AM 的 GSH 可用性，从而导致 AM 功能受损。 在胎儿 ETOH 暴露的豚鼠模型中，初步研究表明，与妊娠匹配的对照相比，ETOH 会降低胎儿上皮衬里液中的 GSH，导致 AM GSH 降低。 暴露于 ETOH 的 AM 表现出功能受损、氧化应激增加和细胞凋亡加剧。 这具有临床相关性，因为它表明，如果 ETOH 暴露的慢性氧化应激叠加在早产上，未成熟 AM 的功能可能会进一步受损。 体内或体外添加 GSH 前体部分恢复了 AM 功能并减少了暴露于 ETOH 的 AM 的细胞凋亡。 我们假设子宫内慢性 ETOH 暴露会消耗肺泡 GSH，由此产生的慢性氧化应激会损害 AM 功能，例如吞噬作用和活力。 此外，我们假设 GSH 补充剂将减少 ETOH 受损的 AM 中的氧化应激，并改善吞噬作用和活力等功能。 我们提出了四个具体目标来确定：1) 子宫内 ETOH 暴露是否会通过增加妊娠期间的氧化应激和 AM 凋亡来损害 AM 功能，2) 细胞因子刺激是否会进一步损害功能并增加发育中暴露于 ETOH 的 AM 的凋亡，3) 体外补充 GSH 是否可以恢复暴露于 ETOH 的 AM 功能并减少细胞凋亡，以及 4) 在摄入 ETOH 期间施用的体内 GSH 前体是否可以保护发育中的 AM 免受 ETOH 的影响诱导功能障碍、氧化应激和细胞凋亡。 该提案的结果将确定胎儿 ETOH 暴露对肺内 AM 发育的新影响，为优化早产新生儿中这些细胞的功能的潜在临床策略提供新的见解。

DESCRIPTION (provided by applicant): Premature newborns are at increased risk of pulmonary infection due to the immaturity of inflammatory cells including the alveolar macrophage (AM). The AM is the first line of defense against infection in the lung. Glutathione, (GSH) a major antioxidant in the lung, is required by the AM to maintain redox potential and optimize intracellular functioning. Levels of systemic and alveolar GSH are deficient in the premature newborn, placing the lung at increased risk for oxidant injury and cellular dysfunction. Chronic alcohol (ETOH) exposure to adults also increases systemic oxidative stress and impairs the immune function of the AM. ETOH consumption has increased significantly in women of childbearing age and remains a significant health problem in our society. The fetus exposed to ETOH in utero is at risk for systemic oxidant stress, as evidenced by decreased systemic and hepatic GSH, and increased markers of reactive oxygen species. We postulate that the pulmonary GSH deficiency caused by prematurity is exacerbated when superimposed on oxidant stress, such as that caused by in utero ETOH exposure. Decreased GSH in the lung decreases GSH availability for the resident AM, thereby contributing to impaired AM function. In a guinea pig model af fetal ETOH exposure, preliminary studies showed that ETOH decreased GSH in the fetal epithelial lining fluid, resulting in decreased AM GSH compared to gestationally matched controls. The ETOH-exposed AM demonstrated impaired functions, increased oxidative stress, and accentuated apoptosis. This is clinically relevant because it suggested that the functions of the immature AM may be further impaired if the chronic oxidative stress of ETOH exposure is superimposed on premature delivery. The addition of GSH precursors in vivo or in vitro partially restored AM function and reduced apoptosis of ETOH-exposed AM. We hypothesize that chronic in utero ETOH exposure depletes alveolar GSH and the resultant chronic oxidative stress impairs AM functions such as phagocytosis and viability. Furthermore, we hypothesize GSH supplements will decrease oxidative stress in the ETOH-impaired AM and improve functions such as phagocytosis and viability. We propose Four Specific Aims to determine: 1) if in utero ETOH exposure impairs AM function by increasing oxidative stress and AM apoptosis across gestation, 2) if cytokine stimulation further impairs function and increases apoptosis of the developing ETOH-exposed AM, 3) if in vitro GSH supplementation restores ETOH-exposed AM functions and reduces apoptosis, and 4) if in vivo GSH precursors, administered during ETOH ingestion, protect the developing AM from ETOH induced dysfunction, oxidative stress and apoptosis. Results from this proposal will identify novel effects of fetal ETOH exposure on the developing AM within the lung, providing new insight on potential clinical strategies to optimize the function of these cells in the premature newborn.