白介素-17A在小鼠慢性胰腺炎中的作用研究

Involvement of Interleukin-17A in Caerulein-induced Chronic Pancreatitis in Mice

目的:研究白细胞介素-17A在小鼠慢性胰腺炎模型中的表达及其对小鼠星状细胞的影响。方法:建立雨蛙肽诱导的小鼠实验性慢性胰腺炎动物模型,利用实时荧光定量PCR、ELISA、免疫组化和Western-blot等手段检测白介素-17A在雨蛙肽诱导的小鼠慢性胰腺炎模型中的表达变化及免疫活性。用重组白介素-17A作用于小鼠胰腺星状细胞,检测其对星状细胞活化的作用,并进一步探究其对促胰腺纤维化炎症因子白介素-6、白介素-1β、TGF-β在mRNA水平的表达变化。结果:慢性胰腺炎胰腺组织中白介素-17A受体IL-17RA及IL-17RC mRNA水平的表达较正常胰腺明显升高,慢性胰腺炎小鼠胰腺组织中IL-17A蛋白水平较正常小鼠明显升高,CP小鼠血清中IL-17A蛋白水平(56.40±10.50 pg/L)较NC组(27.88±5.74pg/L)亦明显升高,IL-17A在正常胰腺组织中鲜有表达(8.9±2.72%),而在CP组织中呈强阳性表达(55.84±5.71%),其免疫活性主要定位于间质炎性细胞及导管样复合体中;重组白介素-17A可促进小鼠星状细胞活化,并直接诱导星状细胞表达白介素-6、白介素-1β以及TGF-β等促纤维化细胞因子。结论:白介素-17A在雨蛙肽诱导的小鼠慢性胰腺炎模型中表达上调,并可能通过诱导小鼠星状细胞表达促炎细胞因子白介素-6、白介素-1β和TGF-β,促进胰腺星状细胞活化以及胰腺纤维化。

Objective： Interleukin（IL）-17 A palys an vital role in various in ammatory diseases such as chronic inflammation and autoimmune diseases including autoimmune pancreatitis, but the role of IL-17 A in chronic pancreatitis has not been clarified. This study aimed to study the role of IL-17 A in experimental chronic pancreatitis（CP） induced by caerulein in mice. Methods： We firstly examined the expression levels of IL-17 A during caerulein-induced CP in vivo in mice by q RT-PCR, Western blotting, ELISA, and immunoreactivity by immunohistochemistry. The effects of IL-17 A on pancreatic stellate cells（PSCs） were further investigated in vitro using recombinant IL-17A（r IL-17A）. Results： Expression of IL-17 RA and IL-17 RC mRNAs were remarkably upregulated during CP, IL-17 A protein level in pancreatic tissues was increased aftrer stimulation with caerulein, the serum concentration of IL-17 A was also significantly elevated in CP mice（56.40±10.50 pg/L） compared with NC group（27.88±5.74pg/L）. Immunoreactivity of IL-17 A was rarely examined in normal pancreatic tissue（8.9±2.72%）, but the positive cells were remarkebly increased in CP mice（55.84±5.71%）, which were mainly localized in interstitial inflammatory cells and tubular complexes. Futhermore, rIL-17 A promoted activation of pancreatic stellate cell in vitro, and directly stimulated expression of several profibrotic genes, including IL-6, IL-1β and TGF-β in PSCs. Conclusion： IL-17 A plays a role in activating PSCs by inducing the expression of Chronic pancreatitis mediators, and probably promote pancreatic fibrosis during experimental chronic pancreatitis.