Heamtopoietic Stem Cells & Lympho-Hematopoiesis: Effect of Alcohol

描述（由申请人提供）：慢性摄入酒精会影响造血的许多方面和造血谱系细胞的功能。慢性酒精的有害影响包括血小板减少症、中性粒细胞减少症和淋巴细胞减少症以及全细胞减少症。骨髓细胞空泡化是常见的，虽然罕见，但也观察到骨髓细胞增多。许多患者表现出与中性粒细胞减少和淋巴细胞减少相关的明显免疫缺陷。在酒精患者中观察到的血液学并发症表明，酒精滥用对造血系统提出了过度的要求。在整个生命过程中，造血系统是由一群自我更新的多能造血干细胞（HSC’s）维持的，这些干细胞通过产生寡能祖细胞产生所有的造血谱系。造血干细胞在骨髓中是罕见的，但由于它们的自我更新，它们寿命很长，在正常情况下不会在生物体的生命周期内耗尽。然而，有研究表明造血干细胞在特殊情况下可能会耗尽。本研究的假设是，酒精滥用会对造血系统产生过度的需求，从而导致造血干细胞过早衰老。也将讨论的推论假设是酒精对HSC有直接的毒性作用；酒精对骨髓微环境产生不利影响，导致造血功能异常。本研究的目的是通过小鼠模型确定慢性酒精摄入对造血干细胞数量、寿命和功能的影响。酒精对造血发育不同阶段的影响将在表型和功能水平上确定，对微环境的影响将通过确定对造血细胞因子表达的影响和骨髓维持造血能力的影响来评估。酒精对HSC体内功能的影响将通过限制稀释的竞争性重构试验来确定。为了确定酒精是否会加速HSC的衰老，将在三年的时间内进行HSC的二次和第三次移植。为了确定正常静止的HSC是否被酒精喂养激活，这些细胞对细胞毒性药物的敏感性将通过定量存活的HSC和测定注射细胞毒性药物后骨髓稳态恢复的速率来评估。

DESCRIPTION (provided by applicant): Chronic ingestion of alcohol can affect many aspects of hematopoiesis and the function of hematopoietic lineage cells. The deleterious effects of chronic alcohol include thrombocytopenia, neutropenia and lymphopenia, as well as pancytopenia. Vacuolization of bone marrow cells is common and, although rare, hypocellularity of the bone marrow has been observed. Many patients show a marked immunodeficiency associated with neutropenia and lymphopenia. The hematological complications observed in alcoholic patients suggest that alcohol abuse places excessive demands on the hematopoietic system. Throughout life, the hematopoietic system is maintained by a population of self-renewing, pluripotent hematopoietic stem cells (HSC's) that generate all of the hematopoietic lineages through the production of oligopotent progenitors. HSCs are rare in the bone marrow yet, due to their self-renewal, they are long-lived and under normal circumstances are not depleted within the lifetime of the organism. However, there are studies that suggest that HSCs can be exhausted under extraordinary circumstances. The hypothesis to be tested in this proposal is that alcohol abuse imparts excessive demands on the hematopoietic system that can lead to premature senescence of HSC's. Corollary hypotheses that will also be addressed are that alcohol has a direct toxic effect on HSC's; and alcohol adversely affects the microenvironment of the bone marrow leading to aberrant hematopoiesis. The goals of this proposal are to determine the effects of chronic alcohol ingestion on the number, longevity, and function of HSCs using a murine model. The effects of alcohol on the different stages of hematopoietic development will be determined at the phenotypic and functional levels and the effects on the microenvironment will be assessed by determining the effects of on the expression of hematopoietic cytokines and the ability of the marrow to sustain hematopoiesis. The effects of alcohol on the in vivo function of HSC's will be determined by competitive reconstitution assays at limiting dilution. To determine if alcohol accelerates senescence of HSC's secondary and tertiary transplantations of HSC's will be done over a three-year period. To determine whether normally quiescent HSC's are activated by alcohol feeding, the sensitivity of these cells to cytotoxic drugs will be assessed by quantitating surviving HSC's and determining the rate of recovery of bone marrow homeostasis following injection of the cytotoxic drug.