Xu Aijing, Zhu Wei, Li Tang, Li Xiuzhen, Cheng Jing, Li Cuiling, Yi Peng, Liu Li
Department of Pediatric Endocrinology and Metabolism, Guangzhou Women and Children's Medical Center, Guangzhou Medical College, Guangzhou, Guangdong 510520, P.R. China.
Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, Guangdong Medical College, Dongguan, Guangdong 523808, P.R. China.
Mol Med Rep. 2015 Sep;12(3):3881-3889. doi: 10.3892/mmr.2015.3809. Epub 2015 May 21.
Type 1 diabetes is an autoimmune disorder, which occurs due to β cell damage. Interleukin (IL)-10, a pleotropic cytokine, has been reported to have anti‑inflammatory, immunosuppressive and immunostimulatory properties. Administration of IL‑10 is known to prevent autoimmune diabetes in non‑obese diabetic (NOD) mice. However, the mechanism of IL‑10‑induced protection in NOD mice requires further investigation. The aim of the present study was to evaluate the protective effect of transgenic IL‑10 expression in pancreatic β cells against autoimmune damage in NOD mice and to elucidate its mechanism of action. Female NOD mice (9 weeks old) were intraperitoneally injected with an adenovirus carrying either IL‑10 (Adv‑IL‑10) or green fluorescent protein (Adv‑GFP). Blood glucose was monitored weekly and the expression of IL‑10 was evaluated using reverse transcription quantitative polymerase chain reaction. IL‑10 and interferon (IFN)‑γ expression levels in serum and splenocytes were analyzed. CD4+CD25+FoxP3+ T regulatory (Treg) cells were determined by flow cytometry. Apoptosis of pancreatic β cells was determined using a terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick‑end labeling assay and expression levels of Fas and caspase‑3 were estimated by immunohistochemistry analysis. The results revealed that mice treated with IL‑10 showed less severe insulitis and a lower incidence of diabetes compared with the saline control and Adv‑GFP groups. In addition, compared with the control group, IFN‑γ levels were decreased in sera and splenocytes, while IL‑10 expression was increased in sera only. The number of CD4+CD25+FoxP3+ Treg cells was increased in IL‑10‑injected mice. Furthermore, the expression levels of Fas and caspase‑3 were decreased in IL‑10‑injected mice compared with that of GFP‑injected and control mice, which was concomitant with a reduction in β cell apoptosis. In conclusion, the present study demonstrated that IL‑10 gene transfer reduced the expression of the inflammatory cytokines, attenuated pancreatic insulitis and inhibited β cell apoptosis. This therefore indicated that IL-10 reduced the incidence of diabetes in female NOD mice.
1型糖尿病是一种自身免疫性疾病，由β细胞损伤引起。白细胞介素（IL）-10是一种多效性细胞因子，据报道具有抗炎、免疫抑制和免疫刺激特性。已知给予IL-10可预防非肥胖糖尿病（NOD）小鼠的自身免疫性糖尿病。然而，IL-10在NOD小鼠中诱导保护作用的机制需要进一步研究。本研究的目的是评估胰腺β细胞中转基因IL-10表达对NOD小鼠自身免疫损伤的保护作用，并阐明其作用机制。将9周龄雌性NOD小鼠腹腔注射携带IL-10（Adv-IL-10）或绿色荧光蛋白（Adv-GFP）的腺病毒。每周监测血糖，并使用逆转录定量聚合酶链反应评估IL-10的表达。分析血清和脾细胞中IL-10和干扰素（IFN）-γ的表达水平。通过流式细胞术测定CD4+CD25+FoxP3+调节性T（Treg）细胞。使用末端脱氧核苷酸转移酶脱氧尿苷三磷酸缺口末端标记法测定胰腺β细胞的凋亡，并通过免疫组织化学分析估计Fas和caspase-3的表达水平。结果显示，与生理盐水对照组和Adv-GFP组相比，接受IL-10治疗的小鼠胰岛炎较轻，糖尿病发病率较低。此外，与对照组相比，血清和脾细胞中的IFN-γ水平降低，而仅血清中的IL-10表达增加。注射IL-10的小鼠中CD4+CD25+FoxP3+Treg细胞数量增加。此外，与注射GFP的小鼠和对照小鼠相比，注射IL-10的小鼠中Fas和caspase-3的表达水平降低，这与β细胞凋亡减少相关。总之，本研究表明，IL-10基因转移降低了炎性细胞因子的表达，减轻了胰腺胰岛炎并抑制了β细胞凋亡。因此，这表明IL-10降低了雌性NOD小鼠的糖尿病发病率。
