Poly (I:C) promotes iodine excess-induced chronic lymphocytic thyroiditis in NOD mouse / 中国病理生理杂志

ABSTRACT

AIM: To investigate the effects of poly (I:C) as virus mimics on iodine excess-induced chronic lymphocytic thyroiditis in NOD mouse. METHODS: Female, 32 NOD mice were randomly divided into 4 groups: (1) control;(2) high iodine;(3) poly (I:C);(4) high iodine+poly (I:C). Nine weeks after administration, mice were sacrificed. The following parameters were determined: body weight, thyroid weight and anatomic form. Thyroid hormone (T_4) in serum was measured by radioimmunoassay, the thyroid morphology was observed through HE staining, apoptosis was detected by TUNEL, the mRNA expression levels of TRAIL, TRAIL-sR1, ICAM-1 and CXCL10 were determined by the method of real time RT-PCR. RESULTS: Compared to control group and poly (I:C) group, the thyroid absolute weight and relative weight in high iodine group were increased (P<0.01), the level of total T_4 in serum was decreased (P<0.05), inflammation and apoptosis were obviously observed, the mRNA expressions of TRAIL, TRAIL-sR1, CXCL10 and ICAM-1 were upregulated (P<0.05). Compared to high iodine group, thyroid absolute weight and relative weight in high iodine+poly (I:C) group were further increased, the level of total T_4 in serum was further decreased (P<0.05), the ratio of inflammatory degree Ⅳ increased to 50.0%, the numbers of apoptosis cells were further enhanced, the mRNA expressions of TRAIL, TRAIL-sR1, ICAM-1 and CXCL10 were further upregulated (P<0.05). Otherwise, the tendency of all parameters in poly (I:C) group was similar to that in control group (P>0.05). CONCLUSION: Poly (I:C) aggravates chronic lymphocytic thyroiditis induced by excess of iodine associated with increase in infiltration of lymphocytes and induction of apoptosis.