Expression Of Nuclear Transcription Factor κB And Vimentin In Hashimoto's Thyroiditis And Their Correlation

Hashimoto's thyroiditis (HT), also called chronic lymphocytic thyroiditis, or lymphomatoid goiter, is one of the organ-specific autoimmune diseases in the world. It was firstly reported by Hashimoto in Japan in 1912. HT has family aggregation and a high prevalence among middle-aged females. Pathologically, this disease is characterized by lymphocyte infiltration, follicular epithelial cells destruction and interstitial fibrosis. With the progression of the disease, the thyroid epithelium will experience damage, repair and fibrosis continuously.Vimentin is a member of intermediate filament family and it is usually expressed in mesenchymal tissues or bidirectional differentiatied cell cytoplasm. Normally, Vimentin is expressed rarely in epithelial cells. In recent years, several research groups report that expression of Vimentin can be found in normal epithelium of thyroid and HT, but the number of the case is very small in their study. Little is known about the expression of vimentin in thyroid epithelium, and its increased expression with the pathogenesis of HT. NF-κB is a kind of nucleic protein factor with its pleiotropia transcription regulation. It is involved in the expression and regulation of many genes, expecially in genes related immune and inflammatory reactions, and plays an important role in human inflammatory reactions. Many data have shown the role of NF-κB in the pathogenesis of thyroid carcinomas, however, there is no report about the expression of NF-κB in Hashimoto's Thyroiditis, the correlation of NF-κB and Vimentin and the mechanism of epithelial-mesenchymal transformation ( EMT ) in thyroid epithelium.In this study, Vimentin and NF-kB were detected by immunohistochemistry (IHC) staining in 28 HT specimens and 9 normal thyroid specimens. 3 specimens expressed both Vimentin and NF-kB were selected for immunofluorescence (IF) double-staining assay. The co-expressions of CK8 and Vimentin, NF-kB and Vimentin were observed by confocal laser scanning microscope. The results showed that the mean positive rates of Vimentin in the two groups were 68.9±39.87% and 22.4±34.63% respectively, and there exists a significant difference statistically (P=0.004). The positive rates of NF-κB in the HT group and the control group were 64.29% (18/28) and 11.11% (1/9) respectively, with a significant difference statistically (P=0.008). The expression of Vimentin was closely related to that of NF-κB (Spearman correlation r=0.662,P<0.01). IF double-staining assays showed that CK8 and Vimentin, and Vimentin and NF-κB co-existed in the cytoplasm of epithelial cells in the HT. We demonstrated that the follicular epithelial cells exist epithelial-mesenchymal transformation (EMT) in HT, and it may be attributable to the increased expression of NF-κB.In summary, we investigated the expressions of NF-κB and Vimentin both in HT and normal thyroid, and their possible relationship, explored that NF-κB might play a role in the pathogenesis of HT.