Alcohol-induced Osteoimmunopathies: A Unifying Explanatory Mechanism

酒精性骨免疫病：一种统一的解释机制 酗酒促进骨质疏松症的发展。酒精滥用者骨质疏松的患病率 估计为28-52%，而所有美国成年人的患病率约为10%。酗酒 还会抑制先天和后天免疫功能，导致更高的感染率 发病率和死亡率增加。这些明显无关的酗酒后果是错综复杂地联系在一起的 通过酒精对破骨细胞和髓系树突状细胞的影响 (MDCS)：破骨细胞-树突状细胞(ODC)前体。因为它在骨骼维护和免疫方面的作用 在细胞生产方面，ODC是骨骼和免疫系统的关键。这种相互依赖使 骨免疫系统特别容易受到长期饮酒对ODC的影响。 RANK/c-fos和Wnt/FrizzledFZD/？-catenin通路是参与ODC的两个主要信号系统 分别向破骨细胞和MDCs分化。这两条信号通路的整合发生了 通过缺口信号。缺口激活通过抑制RANK抑制破骨细胞生成 转录的同时促进FZD(Wnt受体)基因的表达，促进树突状细胞的生成。慢性酒精 消费抑制了恒河猴骨髓细胞中的Noch活性。此外，慢性 饮酒通过增加RANK表达降低FZD受体基因表达 表观遗传机制(RANK启动子CpG低甲基化和FZD启动子CpG高甲基化)。 关于这些祖细胞信号通路之间的相互作用的信息很少，而且 酒精对这些信号和表观遗传机制的影响仍有待研究。我们的假设是 长期饮酒失调了控制脑细胞平衡的关键信号机制 ODC祖细胞谱系分化，导致破骨细胞生成增强和受损 树突状细胞的形成。为解决三个特定目标而设计的实验将检验慢性 饮酒：(1)通过上调RANK信号促进破骨细胞生成；(2)损害 抑制FZD/β-连环蛋白信号通路的树突状细胞生成；以及(3)改变启动子CpG甲基化。 RANK和FZD基因，进一步失衡ODC祖细胞分化。基因组甲基化 在K99期间，将掌握技术以及慢病毒载体的生产和相关的方案 句号。这些技术将被用于在R00期间完成拟议的研究。格兰特 在R00阶段，提案撰写和指导职责将补充实验室研究。 拟议的实验方法将采用临床上相关的慢性酒精消费模型 恒河猴和一些尖端技术。这项调查还将确定关键目标 开发治疗干预措施来治疗酗酒者的骨免疫功能障碍。

Alcohol-induced Osteoimmunopathies: A Unifying Explanatory Mechanism Alcohol abuse promotes the development of osteoporosis. The prevalence of osteoporosis in alcohol abusers is estimated to be 28-52% compared to approximately 10% prevalence for all adult Americans. Alcohol abuse also suppresses both innate and acquired immune function leading to a higher incidence of infections with increased morbidity and mortality. These apparently unrelated outcomes of alcohol abuse are intricately linked through the effects of alcohol on the cell that is the origin of both osteoclasts and myeloid dendritic cells (mDCs): the osteoclast-dendritic cell (ODC) progenitor. Because of its role in bone maintenance and immune cell production, the ODC is a linchpin of the skeletal and immune systems. This interdependence makes the osteoimmune system particularly vulnerable to the effects of chronic alcohol consumption on the ODC. RANK/c-FOS and Wnt/Frizzled (FZD)/¿-catenin pathways are two major signaling systems involved in ODC differentiation to osteoclasts and mDCs, respectively. Integration of these two signaling pathways occurs through NOTCH signaling. NOTCH activation suppresses osteoclastogenesis through inhibiting RANK transcription while promoting FZD (Wnt receptor) gene expression, enhancing dendropoiesis. Chronic alcohol consumption suppressed NOTCH activity in bone marrow cells of rhesus macaques. Furthermore, chronic alcohol consumption increased RANK expression and decreased FZD receptor gene expression through epigenetic mechanisms (RANK promoter CpG hypomethylation and FZD promoter CpG hypermethylation). Little information is available regarding the interplay among these progenitor cell signaling pathways, and the impact of alcohol on these signaling and epigenetic mechanisms remains to be examined. Our hypothesis is that chronic alcohol consumption dysregulates key signaling mechanisms controlling the balance of ODC progenitor lineage differentiation, which leads to enhanced osteoclastogenesis and impaired dendropoiesis. Experiments designed to address three Specific Aims will test the hypotheses that chronic alcohol consumption: (1) promotes osteoclastogenesis through upregulation of RANK signaling; (2) impairs dendropoiesis by inhibiting the FZD/¿-catenin signaling pathway; and (3) alters promoter CpG methylation in RANK and FZD genes, further unbalancing ODC progenitor cell differentiation. Genome methylation techniques, as well as lentiviral vector production and the associated protocols will be mastered during the K99 period. These techniques will be employed to complete the proposed research during the R00 period. Grant proposal writing and mentoring duties will complement laboratory research during the R00 phase. The proposed experimental approach will employ a clinically relevant model of chronic alcohol consumption in rhesus macaques and a number of cutting edge technologies. This investigation will also identify key targets for developing therapeutic interventions to treat osteoimmune dysfunction in alcohol abusers.