title: Polyinosine-polycytidylic acid promotes excessive iodine intake induced thyroiditis in non-obese diabetic mice via Toll-like receptor 3 mediated inflammation.
abstract: BACKGROUND
  Excessive iodine intake and viral infection are recognized as both critical factors associated with autoimmune thyroid diseases. Toll-like receptors (TLRs) have been reported to play an important role in autoimmune and inflammatory disorders. In this study, we aimed to clarify the possible mechanism of TLR3 involved in polyinosine-polycytidylic acid (poly(I:C)) promoting excessive iodine intake induced thyroiditis in non-obese diabetic (NOD) mice.
  
  
  METHODS
  Both NOD and BALB/c mice were randomly assigned to four groups: control group (n = 5), high iodine intake (HI) group (n = 7), poly(I:C) group (n = 7) and combination of excessive iodine and poly(I:C) injection (HIP) group (n = 7). After 8 weeks, mice were weighed and blood samples were collected. All the mice were sacrificed before dissection of spleen and thyroid gland. Then, thyroid histology, thyroid secreted hormone, expression of CD3(+) cells and TLR3 as well as inflammatory mRNA level were evaluated.
  
  
  RESULTS
  Both NOD and BALB/c mice from HI and HIP group represented goiter and increasing thyroid relative weight. Thyroid histology evidence indicated that only HIP group of NOD mice showed severe thyroiditis with lymphocytes infiltration in majority of thyroid tissue, severe damage of follicles and general fibrosis. Immunofluorescence staining results displayed a large number of CD3(+) cells in HIP NOD mice. Real-time polymerase chain reaction (PCR) results suggested interferon (IFN)-α increased over 30 folds and IFN-γ expression was doubled compared with control group, but interleukin (IL)-4 remained unchanged in HIP group of NOD mice thyroid. Meanwhile, over one third decrease of blood total thyroxine (TT4) and increased thyroid-stimulating hormone (TSH) was observed in HIP group of NOD mice. Only HIP group of NOD mice represented significantly elevation of TLR3 expression.
  
  
  CONCLUSIONS
  Poly(I:C) enhanced excessive dietary iodine induced thyroiditis in NOD mice through increasing TLR3 mediated inflammation.
authors: 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, Key Laboratory of Hormones and Development (Ministry of Health), Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, China.
authors: Ya-nan
authors: YN
authors: Shi
authors: Feng-hua
authors: FH
authors: Liu
authors: Xiu-jie
authors: XJ
authors: Yu
authors: Ze-bing
authors: ZB
authors: Liu
authors: Qing-xin
authors: QX
authors: Li
authors: Ji-hong
authors: JH
authors: Yuan
authors: Xiao-yi
authors: XY
authors: Zang
authors: Lan-ying
authors: LY
authors: Li
mesh_terms: D000818:Animals; D005260:Female; D007249:Inflammation / Q000139:chemically induced* / Q000378:metabolism*; D007455:Iodine / Q000633:toxicity*; D051379:Mice; D016688:Mice, Inbred NOD; D011070:Poly I-C / Q000494:pharmacology*; D013966:Thyroiditis / Q000139:chemically induced* / Q000276:immunology* / Q000378:metabolism; D051196:Toll-Like Receptor 3 / Q000378:metabolism*
chemical_list: D051196:Toll-Like Receptor 3; D007455:Iodine; D011070:Poly I-C