Severe alcohol-associated hepatitis (AH) is a life-threatening form of alcohol-associated liver disease. Liver neutrophil infiltration is a hallmark of AH, yet the effects of alcohol on neutrophil functions remain elusive. Identifying therapeutic targets to reduce neutrophil-mediated liver damage is essential. Bruton's tyrosine kinase (BTK) plays an important role in neutrophil development and function; however, the role of BTK in AH is unknown. Using RNA sequencing of circulating neutrophils, we found an increase in Btk expression (P = 0.05) and phosphorylated BTK (pBTK) in patients with AH compared with healthy controls. In vitro, physiologically relevant doses of alcohol resulted in a rapid, TLR4-mediated induction of pBTK in neutrophils. In a preclinical model of AH, administration of a small-molecule BTK inhibitor (evobrutinib) or myeloid-specific Btk knockout decreased proinflammatory cytokines and attenuated neutrophil-mediated liver damage. We found that pBTK was essential for alcohol-induced bone marrow granulopoiesis and liver neutrophil infiltration. In vivo, BTK inhibition or myeloid-specific Btk knockout reduced granulopoiesis, circulating neutrophils, liver neutrophil infiltration, and liver damage in a mouse model of AH. Mechanistically, using liquid chromatography-tandem mass spectrometry, we identified CD84 as a kinase target of BTK, which is involved in granulopoiesis. In vitro, CD84 promoted alcohol-induced interleukin-1β and tumor necrosis factor-α in primary human neutrophils, which was inhibited by CD84-blocking antibody treatment. Our findings define the role of BTK and CD84 in regulating neutrophil inflammation and granulopoiesis, with potential therapeutic implications in AH.

中文翻译：

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体内 Bruton 的酪氨酸激酶抑制作用通过调节 CD84 介导的粒细胞生成来减轻酒精相关的肝病。


严重酒精相关性肝炎 (AH) 是一种危及生命的酒精相关性肝病。肝脏中性粒细胞浸润是 AH 的标志，但酒精对中性粒细胞功能的影响仍然难以捉摸。确定减少中性粒细胞介导的肝损伤的治疗靶点至关重要。布鲁顿酪氨酸激酶（BTK）在中性粒细胞发育和功能中发挥着重要作用；然而，BTK 在 AH 中的作用尚不清楚。通过对循环中性粒细胞进行 RNA 测序，我们发现与健康对照相比，AH 患者的 Btk 表达 (P = 0.05) 和磷酸化 BTK (pBTK) 有所增加。在体外，生理相关剂量的酒精导致中性粒细胞中 TLR4 介导的 pBTK 快速诱导。在 AH 的临床前模型中，给予小分子 BTK 抑制剂（evobrutinib）或骨髓特异性 Btk 敲除可减少促炎细胞因子并减轻中性粒细胞介导的肝损伤。我们发现 pBTK 对于酒精诱导的骨髓粒细胞生成和肝脏中性粒细胞浸润至关重要。在体内，BTK 抑制或骨髓特异性 Btk 敲除可减少 AH 小鼠模型中的粒细胞生成、循环中性粒细胞、肝脏中性粒细胞浸润和肝损伤。从机制上讲，我们使用液相色谱-串联质谱法确定 CD84 是 BTK 的激酶靶点，参与粒细胞生成。在体外，CD84 促进原代人中性粒细胞中酒精诱导的白细胞介素 1β 和肿瘤坏死因子 α，而 CD84 阻断抗体治疗可抑制这种作用。我们的研究结果明确了 BTK 和 CD84 在调节中性粒细胞炎症和粒细胞生成中的作用，对 AH 具有潜在的治疗意义。