吉西他滨对小鼠实验性自身免疫性心肌炎的影响

Effect of gemcitabine on experimental autoimmune myocarditis in mice

目的:研究吉西他滨对实验性自身免疫性心肌炎(experimental autoimmune myocarditis,EAM)模型小鼠的治疗作用。方法:取15只Balb/c小鼠构建EAM模型,分为对照组,EAM组,EAM+吉西他滨组,每组5只;在第21天,取眼球血,颈椎脱臼处死小鼠,取心脏组织行HE染色,光镜下观察淋巴细胞浸润情况,并行炎症评分;流式细胞术检测脾脏组织中骨髓来源的抑制性细胞(myeloid-derived suppressor cell,MDSC)和Th17细胞比例; ELISA法检测血清中IL-17A浓度; qRT-PCR检测心脏组织中IL-17A mRNA含量。取正常Balb/c小鼠脾脏分选MDSC和Na?veCD4^+T细胞,分为活化组,诱导组,共培养组,流式细胞术检测各组Th17比例。结果:与对照组比较,EAM组心肌组织以炎性细胞浸润和心肌细胞坏死为主,组织炎症评分明显增高(P <0.05);与EAM组比较,EAM+吉西他滨组炎性细胞的浸润和心肌细胞坏死减少,组织炎症评分明显降低(P <0.05);与对照组比较,EAM组脾脏中MDSC和Th17比例明显增加(P <0.05);与EAM组比较,EAM+吉西他滨组二者比例明显降低(P <0.05)。与对照组相比,EAM组IL-17A浓度和IL-17A mRNA表达明显增高(P <0.05);与EAM组比较,EAM+吉西他滨组二者含量明显降低(P <0.05)。与诱导组比较,共培养组Th17比例明显增加(P <0.05)。结论:吉西他滨可能通过降低EAM模型小鼠脾脏中MDSC数量,进而抑制Na?veCD4^+T细胞向Th17细胞的分化从而缓解心肌炎症。

Objective: To study the therapeutic effect of gemcitabine on experimental autoimmune myocarditis ( EAM) model mice. Methods: A total of 15 Balb /c mice were used to construct EAM model and divided into control group,EAM group,EAM + gemcitabine group( n = 5 in each group). On the 21st day,the eyeballs blood were harvested and the mice were sacrificed by cervical dislocation. HE staining was performed to observe lymphocyte infiltration in the cardiac tissue,and the inflammation score was analyzed. Flow cytometry was used to detect the proportion of myeloid-derived suppressor cell ( MDSCs) and Th17 cells in spleen tissues;the concentration of IL-17A in serum was detected by ELISA. The IL-17A mRNA level in cardiac tissue was detected by qRT-PCR. MDSC and Nave CD4^+ T cells were sorted from spleens of Balb /c mice,and divided into activation group,induction group,co-culture group;the Th17 percentage in each group were detected by flow cytometry. Results: Compared with the control group,there was mainly inflammatory cell infiltration and myocardial necrosis in the myocardial tissue of the EAM group. Compared with the EAM group,the infiltration of inflammatory cells and myocardial necrosis were reduced in the EAM + gemcitabine group. Compared with the control group,the myocardial tissue inflammation score of EAM group was significantly increased ( P < 0. 05). Compared with EAM group,the myocardial tissue inflammation score of EAM + Gemcitabine group was significantly lower( P < 0. 05). Compared with the control group,the ratio of MDSC and Th17 in the spleen of EAM group was significantly increased( P < 0. 05). Compared with EAM group,EAM + Gemcitabine group showed lower proportion of MDSC and Th17 cells in the spleen( P < 0. 05). Compared with the control group,the serum IL-17A concentration and IL-17A mRNA in the EAM group were significantly increased ( P < 0. 05). Compared with EAM group,serum IL-17A concentration and IL-17A mRNA level in EAM + gemcitabine group were significantly lower( P < 0. 05). Compared with the induction group,the proportion of IL-17A in the co-culture group was significantly increased( P < 0. 05). Conclusion: In the EAM mouse model,gemcitabine may attenuate myocardial inflammation by inhibiting the amount of MDSC in the mouse spleen and the differentiation of Nave CD4^+ T cells into Th17 cells.