NLRP12对小鼠病毒性肝炎的保护作用及机制探讨

目的 探究NLRP12基因在MHV3（鼠三型肝炎病毒）诱导的小鼠病毒性肝炎中的作用及调控机制。方法 采用不同滴度MHV3病毒诱导野生型及NLRP12基因敲除C57BL/6J小鼠建立病毒性肝炎模型，观察小鼠生存情况，测定血清ALT、AST的表达，HE染色观察肝组织病理改变，TUNEL染色观察细胞凋亡情况，免疫组化染色检测FGL2蛋白表达，全自动生化仪进行小鼠血细胞分类计数，ELISA测定血清炎性细胞因子（IL - 6、TNF - α）及粒细胞集落刺激因子（G - CSF）的表达。结果 致死滴度（50、75和100 pfu）MHV3感染后，相比野生型小鼠，NLRP12基因敲除小鼠生存率明显降低。非致死滴度（25 pfu）MHV3感染情况下，NLRP12基因敲除小鼠呈现更严重的肝脏病理损伤，血清ALT、AST及炎性细胞因子水平更高，血液循环中性粒细胞数量未显著性上调，并伴随粒细胞分化相关标志物（Myadm）的表达降低，但不影响中性粒细胞趋化基因（CXCL1、CXCL2）及G - CSF的表达。结论 NLRP12基因可能通过调控中性粒细胞的发育分化，促进循环中性粒细胞的产生发挥抗病毒作用，从而保护小鼠免于MHV3病毒的感染，提示NLRP12可作为病毒性肝炎潜在的调控靶标。

Exploring the protective effect and mechanism of NLRP12 against viral hepatitis in mice

Objective To investigate the role and regulatory mechanism of NLRP12 gene in MHV3 (murine hepatitis 3 virus)-induced viral hepatitis in mice. Methods A viral hepatitis model was established using wild-type and NLRP12 knockout C57BL/6J mice with different titers of MHV3 virus induction. The survival of mice was observed, the expression of serum ALT and AST was measured, the histopathological changes of liver were observed by H&E staining, apoptosis was observed by TUNEL staining, the expression of FGL2 protein was detected by immunohistochemical staining, and a fully automated biochemical instrument was used for the expression of serum inflammatory cytokines (IL-6, TNF-α) and granulocyte colony-stimulating factor (G-CSF) was determined by ELISA. Results Lethal titers (50, 75, 100 pfu) of MHV3 infection resulted in a significantly lower survival rate in NLRP12 knockout mice compared to wild-type mice. In non-lethal titer (25 pfu) MHV3 infection, NLRP12 knockout mice showed more severe liver pathological damage with higher serum ALT, AST and inflammatory cytokine levels and non-significant upregulation of circulating neutrophil counts, accompanied by reduced expression of granulocyte differentiation-related markers (Myadm), but did not affect neutrophil chemotactic genes ( CXCL1, CXCL2) and G-CSF expression. Conclusion NLRP12 gene may play an antiviral role by regulating the developmental differentiation of neutrophils and promoting the production of circulating neutrophils, thus protecting mice from MHV3 virus infection, suggesting that NLRP12 could be a potential regulatory target for viral hepatitis.