Role of Bone Marrow-Derived Myeloid Cells in Alcohol Liver Disease

描述（由申请人提供）：晚期酒精性肝病（ALD）唯一有效的治疗方法是肝移植。为了促进治疗的发展，必须更好地了解其发病机制。有证据表明，肝巨噬细胞（Macs）发挥了重要作用；然而，到目前为止的研究还没有区分常驻mac， Kupffer细胞（KCs）和浸润性骨髓源性髓样细胞（BMMCs），后者在病理状态下补充KCs。我们在酒精处理的小鼠肝脏中检测到BMMCs并将其与KCs区分开来。我们假设ALD期间招募到肝脏的bmmc具有不同的表型和功能，这取决于微环境和ALD的严重程度。拟议研究的具体目的是：（目的1）研究酒精治疗导致肝脏BMMC积累的机制。a)采集乙醇喂养小鼠的肝脏，检测IL-1b、IL-6、S100A8/A9、HSP72和COX-2的信息表达水平。b)将通过中和抗体和IL-1R-/-小鼠研究IL-1b和S100A8/A9在肝脏BMMCs积累中的特异性参与。c)将利用STAT3hep/-小鼠来检测肝细胞特异性STAT3信号在酒精暴露后肝脏BMMC积累中的作用。（目的2），确定轻度和晚期ALD中BMMCs的表型和功能。a)长期饲喂含5%乙醇的Lieber-Decarli日粮模拟轻度ALD。利用该模型，我们将研究bmmc在促进酒精诱导的微循环障碍修复中的功能，并研究VEGF和MMPs在介导这一功能中的作用。在这些研究中，CD11b-DTR小鼠和抗gr -1抗体将被用于消耗bmmc。b)混合模型，小鼠自由饲喂“西方饮食”并灌胃乙醇，具有酒精性脂肪性肝炎（ASH）和肝纤维化的特征

DESCRIPTION (provided by applicant): The only effective treatment for advanced alcohol liver disease (ALD) is liver transplantation. It is imperative to better understand the pathogenesi in order to advance therapeutic development. Evidence suggests that hepatic macrophages (Macs) play an important role; however research to date has not distinguished resident Macs, Kupffer cells (KCs), from infiltrating bone marrow-derived myeloid cells (BMMCs), which replenish KCs during pathological conditions. We detected BMMCs and distinguished them from KCs in the liver of mice treated with alcohol. We hypothesize that the BMMCs recruited into the liver during ALD assume different phenotypes and functions, depending on the microenvironment and severity of ALD. The Specific Aims of the proposed studies are: (Aim 1), investigate the mechanisms of hepatic BMMC accumulation as result of alcohol treatment. a) Livers from ethanol-fed mice will be harvested to examine message expression levels of IL-1b, IL-6, S100A8/A9, HSP72, and COX-2. b) The specific involvement of IL-1b and S100A8/A9 in hepatic accumulation of BMMCs will be investigated by using neutralizing antibodies and IL-1R-/- mice. c) The STAT3hep/- mice will be utilized to examine the role of hepatocyte-specific STAT3 signaling in BMMC accumulation in the liver after alcohol exposure. (Aim 2), Determine the phenotypes and functions of BMMCs in mild and advanced ALD. a) Chronic feeding of mice with 5% ethanol-containing Lieber-Decarli diet simulates mild ALD. Using this model, we will investigate the function of BMMCs in promoting the repair of alcohol-induced microcirculation disorder, and examine the roles of VEGF and MMPs in mediating such function. The CD11b-DTR mice and anti-Gr-1 antibody will be employed to deplete BMMCs in these studies. b) A hybrid model, in which mice are fed ad libitum with "Western diet" and intragastrically infused with ethanol, shares characteristics of alcoholic steatohepatitis (ASH) and liver fibrosis found in patients with advanced ALD. This model will be employed to examine the phenotype of BMMCs, and investigate their contribution to liver injury. (Aim 3), Dissect the molecular regulations of BMMC phenotypes in mild and advanced ALD. a) The systemic and hepatic levels of endotoxin and damage-associated molecular pattern (DAMP) molecules will be measured in the hybrid model of ALD. b) The contributions of endotoxin and DAMPs to pro-inflammatory activation of BMMCs and liver damage in the hybrid model will be investigated by administering mice with rifaximin antibiotic, and inhibitors of DAMPs. c) STAT3 activation and STAT1/NF-kB activation in BMMCs associated with mild ALD and ASH, respectively, will be investigated.