目的 基于高迁移率族蛋白 1（HMGB1）/外泌体（EVs）信号转导和转录活化因子 3（STAT3） 途径探讨抗结核药吡嗪酰胺（PZA）肝损伤的机制。方法 将 24 只 WT 小鼠随机分为两组：WT+Con 组、 WT+PZA 组；以及将 24 只 HMGB1 基因敲除（HMGB1⁃KO）小鼠随机分为两组：HMGB1⁃KO+Con 组、HMGB1⁃ KO+PZA 组。分别采用免疫印迹分析小鼠肝脏组织中 HMGB1 表达和 M1/M2 巨噬细胞极化。体外实验中， 通过 CCK⁃8 实验检测梯度浓度的 PZA（0 、2 、4 、8 、16 、32 μmol/L）对人肝细胞系 Huh7 活力影响。通过超 速离 心分离 HMGB1 过度表达的 Huh7 细胞释放的 EVs，并分析其对巨噬细胞（THP⁃1）活化的影响。用 HMGB1 siRNAs 转染 PZA 处理的 Huh7 细胞，并分离 EVs 以检测 STAT3 的蛋白水平。结果 与 0 d 相比， PZA 给药后 4 d 、8 d 、12 d 、16 d 小鼠的肝组织中的 HMGB1 水平均显著增加（P < 0.05）。细胞活力显示 PZA抑制Huh7细胞增殖，IC50值为（5.62 ± 0.39）μmol/L。与WT+Con组相比，在WT+PZA组中，观察到明显的 进行性体质量损失（P < 0.001），和血清 ALT、AST 水平显著升高（P < 0.01）。与 WT+PZA 组相比，HMGB1⁃ KO+PZA 组体质量显著增加（P < 0.001），和血清 ALT、AST 水平显著降低（P < 0.05）。与 WT+PZA 组相 比， HMGB1⁃KO+PZA 组肝组织中 i⁃NOS 表达显著减少（P < 0.001），和 CD206 的表达显著增加（P < 0.05）。与 EVs⁃Vector 组相比，EVs⁃HMGB1 组 THP⁃1 细胞中 iNOS 表达显著增加（P < 0.001）。与 Con+si⁃NC 组相比， PZA+si⁃NC 组 Huh7 细胞 EVs 中 STAT3 的水平增加，而 HMGB1 敲除可以减弱 PZA 的作用。结论 小鼠 HMGB1 基因敲除逆转了 PZA 诱导的肝损伤和 M1 巨噬细胞激活。此外，PZA 诱导的 HMGB1 上调可以促 进肝细胞分泌富含STAT3的EVs，并且该EVs 能促进M1巨噬细胞极化。

Objective To explore the mechanism of liver injury induced by antituberculosis drug pyrazin⁃ amide（PZA）based on high mobility group protein 1（HMGB1）/extracellular vesicles（EVs）signal transducer and activator of transcription 3（STAT3）pathway. Methods 24 WT mice were randomly divided into two groups： WT+Con group and WT+PZA group；and 24 HMGB1⁃KO mice were randomly divided into two groups：HMGB1⁃ KO+Con group and HMGB1⁃KO+PZA group. Western blot was used to analyze the HMGB1 expression and the polarization of M1/M2 macrophages in mouse liver. In vitro，CCK⁃8 experiment was used to detect the effect of PZA（0，2，4，8，16，32 μmol/L）with gradient concentration on the activity of Huh7. The EVs released by Huh7 cells overexpressed by HMGB1 was isolated by ultracentrifugation，and its effect on the activation of THP⁃ 1 was analyzed. HMGB1 siRNAs was transfected into PZA⁃treated Huh7 cells，and EVs was isolated to detect the protein level of STAT3. Results Compared with 0 d，the level of HMGB1 in liver tissue of mice on 4 d，8 d，12 d and 16 d after PZA administration was significantly increased（P < 0.05）. Cell viability showed that PZA inhibited the proliferation of Huh7 cells，and the IC50 value was 5.62 ± 0.39 μmol/L. Compared with WT+Con group，in WT+ PZA group，significant progressive weight loss was observed（P < 0.001），and serum ALT and AST levels were significantly increased （P < 0.01）. Compared with WT+PZA group ，the weight of HMGB1⁃KO+PZA group increased significantly（P < 0.001），and the serum levels of ALT and AST decreased significantly（P < 0.05）. Compared with WT+PZA group，the expression of i⁃NOS in liver tissue of HMGB1⁃KO+PZA group decreased signif⁃icantly（P < 0.001），and the expression of CD206 increased significantly（P < 0.05）. Compared with EVs ⁃Vector group，the expression of iNOS in THP⁃ 1 cells in EVs⁃HMGB1 group increased significantly（P < 0.001）. Compared with Con+ si ⁃NC group，the level of STAT3 in EVs of Huh7 cells in PZA+ si ⁃NC group increased，while HMGB1 knockout could weaken the effect of PZA. Conclusion HMGB1 gene knockout in mice reverses PZA⁃induced liver injury and M1 macrophage activation. In addition，PZA⁃induced HMGB1 upregulation can promote the secre⁃ tion of STAT3⁃rich EVs by hepatocytes，and the EVs can promote the polarization of M1 macrophages.