LIGHT在自发Ⅰ型糖尿病小鼠中表达的分析

Analysis of LIGHT expression in NOD mice with experimental typeⅠ diabetes mellitus

目的建立I型糖尿病NOD小鼠模型,探讨LIGHT在I型糖尿病模型NOD小鼠中的表达及意义。方法监测雌性NOD小鼠血糖、胰岛素水平;NOD小鼠分为4组,即未发病5周龄及11周龄组、发病1 w和2 w组。采用qRT-PCR、Western blot、免疫组化技术分析NOD小鼠胰腺组织LIGHT的mRNA、蛋白表达变化;ELISA法检测血清胰岛素、可溶性LIGHT及Th1细胞因子IFN-γ含量;HE染色检测胰岛炎,对胰岛炎评分,并对血清LIGHT含量与IFN-γ含量及胰岛炎积分进行相关性分析。结果糖尿病发病组NOD小鼠胰腺组织LIGHT基因的mRNA和蛋白表达及血清LIGHT浓度均明显高于未发病的5周龄组(P<0.05),血清中Th1细胞因子IFN-γ分泌显著增加。血清LIGHT含量与IFN-γ水平及胰岛炎积分呈明显正相关(r1=0.52,r2=0.87,P<0.01)。结论 LIGHT在NOD小鼠胰腺组织中的表达上调,可能影响Th1细胞因子IFN-γ的分泌及胰岛炎程度,血清LIGHT能反映I型糖尿病胰岛炎的严重程度。

Objective To set up a NOD mouse model for typeⅠdiabetes mellitus,and to investigate the expression and significance of LIGHT in NOD mice. Methods The NOD mice were divided into 4 groups as 2 groups for five week and 11 week old not occurred diabetes,and 2 groups for occurred diabetes for 1 week and 2 week,respectively. The NOD mice were maintained under a specific pathogen-free condition,and blood glucose levels were measured weekly from tested mice.Animals were considered as diabetics when two consecutive blood glucose levels exceeded 250 mg / d L in a week. Total RNA and protein were extracted from fresh pancreatic tissue from tested mice. The mRNA levels and protein levels of LIGHT were determined by qRT-PCR,Western blot and immuno-histochemisty,separatly. ELISA was carried out in detection of concentration for serum insulin,LIGHT and IFN-γ. Pancreatic histopathology was determined with hematoxylin and eosin staining. Besides,the relationship between serum LIGHT concentration and IFN-γ concentration / insulitis scores was statistically analyzed. Results The qRT-PCR,Western blot and immunohistochemisty results showed that the expression level of LIGHT in pancreatic tissue was increased in diabetic mice（ P〈0. 05）. The serum IFN-γ concentration in diabetic mice was significant higher than that in five-week-old mice not occurred diabetes（ P〈0. 01）. serum LIGHT concentration showed a significantly positive correlation with the serum IFN-γ concentration or insulitis scores（ r1= 0. 52,r2= 0. 87,P〈0. 01）. Conclusion The expression of LIGHT was upregulated in NOD mice with diabetes,which might influence to the secretion of IFN-γ and insulitis,and serum LIGHT concentration could reflect the severity of insulitis.