Serum hepatocyte growth factor is increased in Hashimoto's thyroiditis whether or not it is associated with nodular goiter as compared with healthy non-goitrous individuals

Interleukin‑6 signalling as a valuable cornerstone for molecular medicine (Review)

The biological abilities of interleukin-6 (IL-6) have been under investigation for nearly 40 years. IL-6 works through an interaction with the complex peptide IL-6 receptor (IL-6R). IL-6 is built with four α-chain nanostructures, while two different chains, IL-6Rα (gp80) and gp130/IL6β (gp130), are included in IL-6R. The three-dimensional shapes of the six chains composing the IL-6/IL-6R complex are the basis for the nanomolecular roles of IL-6 signalling. Genes, pseudogenes and competitive endogenous RNAs of IL-6 have been identified. In the present review, the roles played by miRNA in the post-transcriptional regulation of IL-6 expression are evaluated. mRNAs are absorbed via the 'sponge' effect to dynamically balance mRNA levels and this has been assessed with regard to IL-6 transcription efficiency. According to current knowledge on molecular and nanomolecular structures involved in active IL-6 signalling, two different IL-6 models have been proposed. IL-6 mainly has functions in inflammatory processes, as well as in cognitive activities. Furthermore, the abnormal production of IL-6 has been found in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; also known as COVID-19). In the present review, both inflammatory and cognitive IL-6 models were analysed by evaluating the cytological and histological locations of IL-6 signalling. The goal of this review was to illustrate the roles of the classic and trans-signalling IL-6 pathways in endocrine glands such as the thyroid and in the central nervous system. Specifically, autoimmune thyroid diseases, disorders of cognitive processes and SARS-CoV-2 virus infection have been examined to determine the contribution of IL-6 to these disease states.

Serum interleukin-6 levels are increased in HIV-infected patients that develop autoimmune disease during long-term follow-up

BACKGROUND

Elevated IL-6 levels have been associated with both autoimmune diseases and treated HIV-seropositive (HIV⁺) subjects. However, few data on classic and trans-signaling IL-6 in autoimmune thyroid diseases and HIV⁺ subjects developing autoimmune disorders are currently available.

MATERIALS AND METHODS

A total of 102 patients were included in the study. They were subdivided into two groups. Group A consisted in 51 HIV⁺ patients, who were followed-up for a period of five years in search of possible occurrence of autoimmune diseases. Ten of them, treated with antiretroviral therapy (ART), developed an autoimmune disorder, namely Hashimoto's thyroiditis, and psoriasis. Group B consisted in 51 patients affected by Hashimoto's thyroiditis (HT). Serum levels of the free form of IL-6 were analyzed by ELISA in all patients and for HIV⁺ patients at the beginning of the follow-up, before initiation of ART.

RESULTS

Mean serum levels of IL-6 were similar in Group A and in Group B. In Group B, IL-6 levels showed a 5.8% increase compared with assay minimum detectable dose corresponding to 1% of full serum IL-6 level. However, serum levels of free IL-6 were increased in those HIV⁺ patients who developed autoimmune disorders (5.8±2.8pg/ml) and in these patients, the highest levels of free IL-6 correlated with age and CD4 cellular counts.

CONCLUSIONS

The present study indicates a correlation between serum free IL-6 levels and the occurrence of autoimmune disease in HIV⁺ population, treated with ART during a long-term follow-up. The increased levels of serum free IL-6 were observed before ART treatment was initiated, indicating that IL-6 measurement in such patients may represent an early predictor of development of autoimmune disease.

Comparative Efficacy and Toxicity of Different Species of Sargassum in Haizao Yuhu Decoction in PTU-Induced Goiter Rats

BACKGROUND

Haizao Yuhu Decoction has been widely used to treat thyroid-related diseases especially goiter with few side effects in traditional Chinese medicine (TCM), including herb pair Sargassum (HZ) and Glycyrrhizae Radix et Rhizoma (GC), as one of "eighteen antagonistic medicaments." The two different species of Sargassum, Sargassum fusiforme (Sf) and Sargassum pallidum (Sp), are not clearly differentiated in clinical use, so that herb pair Sf-GC and Sp-GC could show different effect and toxicity.

METHODS

We investigated the antigoitrous effect and toxicity and clarified the potential underlying mechanism of the two different species of Sargassum in HYD (HYDf and HYDp) in PTU-reduced goiter rats.

RESULTS

The results demonstrated that both HYDf and HYDp could exhibit antigoitrous effect through alterations in hypothalamus-pituitary-thyroid (HPT) axis and inhibition of the TPO gene expression; there is no difference in the antigoitrous effects between the two different species of Sargassum application in HYD.

CONCLUSION

This study evaluated the safety and efficacy of herb pair HZ-GC applied in HYD in goiter rats at molecular, cellular, and whole level and compared the two species of Sargassum further. We provide a reliable way to clarify the possible mechanism of the antagonistic medicament herb pair HZ-GC for its application.

Hepatocyte Growth Factor/C-Met Axis in Thyroid Cancer: From Diagnostic Biomarker to Therapeutic Target

The hepatocyte growth factor (HGF)/c-met axis plays a crucial role in cancer development by promoting cellular proliferation, motility, and morphogenesis, as well as angiogenesis. Different cellular distributions of both the ligand and the receptor in benign vs malignant lesions indicate this biological system as a candidate for a diagnostic biomarker of malignancy occurring in endocrine glands, such as the thyroid and pituitary. Furthermore, the HGF/c-met expression may help to identify a subset of patients eligible for potential targeted therapies with HGF/c-met inhibitors or antagonists in thyroid tumour, as well as in other malignancies. This may be relevant for iodine-refractory cancers, the treatment of which is still a major challenge. With this in mind, HGF/c-met expression in thyroid cancer tissue may be useful for prognostic and therapeutic stratification of patients.

The association between thyroid volume, L-thyroxine therapy and hepatocyte growth factor levels among patients with euthyroid and hypothyroid goitrous and non-goitrous Hashimoto's thyroiditis versus healthy subjects

OBJECTIVE

Hashimoto's thyroiditis (HT) is the most common etiology of hypothyroidism in regions where iodine deficiency is not a concern. To date, many clinical investigations have been conducted to elucidate its pathogenesis. Several growth factors have been shown to have a role in its development. Hepatocyte growth factor (HGF) is one of the aforementioned molecules. We aimed to demonstrate whether HGF is responsible for HT and goiter development. Also, we aimed to test the hypothesis that levo-thyroxine sodium therapy will suppress HGF levels.

MATERIALS AND METHODS

Sixty-one premenopausal women who were admitted to our outpatient clinic between November 2010 and September 2011 were enrolled. Three groups were determined according to their thyroid function tests (TFTs) as euthyroid Hashimoto's, control and subclinical hypothyroid Hashimoto's groups. Basal TFTs, anti-thyroid peroxidase (anti-TPO), anti-thyroglobulin (anti-tg), thyroid ultrasonography (USG) and HGF were studied and recorded. Subclinical hypothyroid HT patients received levo-thyroxine sodium replacement therapy, and were re-assessed for the same laboratory and radiologic features after a median 3.5 month follow-up.

RESULTS

Basal HGF levels were not different between groups. In the subclinical hypothyroidism group, HGF levels (752.75 ± 144.91 pg/ml vs. 719.37 ± 128.05 pg/ml; p = 0.496) and thyroid volumes (12.51 ± 3.67 cc vs. 12.18 ± 4.26 cc; p = 0.7) before and after treatment did not change significantly. No correlations were found between HGF and other parameters. HGF levels were similar between subjects with nodular goiter and normal thyroid structure.

CONCLUSIONS

HGF was not shown to be associated with HT and goiter development. In addition, levo-thyroxine sodium replacement therapy did not alter serum HGF levels significantly.

Cytokine production in patients with papillary thyroid cancer and associated autoimmune Hashimoto thyroiditis

Hashimoto thyroiditis (HT) is the most frequent thyroid autoimmune disease, while papillary thyroid cancer (PTC) is one of the most common endocrine malignancies. A few patients with HT also develop PTC. The aim of this study was to analyze cytokine profiles in patients with PTC accompanied with autoimmune HT in comparison with those in patients with PTC alone or HT alone and healthy subjects. Cytokine levels were determined in supernatants obtained from phytohemagglutinin (PHA)-stimulated whole blood cultures in vitro. The concentrations of selected cytokines: Th1-interferon gamma (IFN-γ); Th2-interleukin 4 (IL-4), interleukin 5 (IL-5), interleukin 6 (IL-6), interleukin 10 (IL-10) and interleukin 13 (IL-13); Th9-interleukin 9 (IL-9); and Th17-interleukin 17 (IL-17A) were measured using multiplex cytokine detection systems for human Th1/Th2/Th9/Th17/Th22. We found that PTC patients with HT produced significantly higher concentrations of IL-4, IL-6, IL-9, IL-13 and IFN-γ than PTC patients without HT. In conclusion, autoimmune HT affects the cytokine profile of patients with PTC by stimulating secretion of Th1/Th2/Th9 types of cytokines. Th1/Th2 cytokine ratios in PTC patients with associated autoimmune HT indicate a marked shift toward Th2 immunity.

HGF/Met-Signaling Contributes to Immune Regulation by Modulating Tolerogenic and Motogenic Properties of Dendritic Cells

Hepatocyte growth factor (HGF)-signaling via Met can induce mitogenic, morphogenic, and motogenic activity in various cell types. Met expression in the immune system is limited to cells with antigen-presenting capacities, including dendritic cells (DCs). Thus, it appears highly conceivable that Met-signaling impacts on adaptive immune responses. However, the mechanisms by which HGF imparts its effects on immunological responses are not yet fully understood. DCs possess unique functionalities that are critically involved in controlling both tolerance and immunity. HGF conveys immunoregulatory functions, which strongly correlate with that of DCs orchestrating the apt immune response in inflammation. Therefore, this review focuses on the current knowledge of Met-signaling in DCs with specific emphasis on the morphogenic and motogenic activities. HGF has been identified to play a role in peripheral immune tolerance by directing DC differentiation towards a tolerogenic phenotype. In skin immunity, Met-signaling was shown to drive mobilization of DCs by regulating matrix metalloproteinase activities. This is strikingly reminiscent of the role of Met for regulating a cell fate program during embryonic development, wound healing, and in tumor invasion known as epithelial-mesenchymal transition (EMT). Thus, the concept emerges that an EMT program is executed by Met-signaling in DCs, which will be also discussed.

Polymorphisms in the TNFA and IL6 genes represent risk factors for autoimmune thyroid disease

BACKGROUND

Autoimmune thyroid disease (AITD) comprises diseases including Hashimoto's thyroiditis and Graves' disease, both characterized by reactivity to autoantigens causing, respectively, inflammatory destruction and autoimmune stimulation of the thyroid-stimulating hormone receptor. AITD is the most common thyroid disease and the leading form of autoimmune disease in women. Cytokines are key regulators of the immune and inflammatory responses; therefore, genetic variants at cytokine-encoding genes are potential risk factors for AITD.

METHODS

Polymorphisms in the IL6-174 G/C (rs1800795), TNFA-308 G/A (rs1800629), IL1B-511 C/T (rs16944), and IFNGR1-56 T/C (rs2234711) genes were assessed in a case-control study comprising 420 Hashimoto's thyroiditis patients, 111 Graves' disease patients and 735 unrelated controls from Portugal. Genetic variants were discriminated by real-time PCR using TaqMan SNP genotyping assays.

RESULTS

A significant association was found between the allele A in TNFA-308 G/A and Hashimoto's thyroiditis, both in the dominant (OR = 1.82, CI = 1.37-2.43, p-value = 4.4×10(-5)) and log-additive (OR = 1.64, CI = 1.28-2.10, p-value = 8.2×10(-5)) models. The allele C in IL6-174 G/C is also associated with Hashimoto's thyroiditis, however, only retained significance after multiple testing correction in the log-additive model (OR = 1.28, CI = 1.06-1.54, p-value = 8.9×10(-3)). The group with Graves' disease also registered a higher frequency of the allele A in TNFA-308 G/A compared with controls both in the dominant (OR = 1.85, CI = 1.19-2.87, p-value = 7.0×10(-3)) and log-additive (OR = 1.69, CI = 1.17-2.44, p-value = 6.6×10(-3)) models. The risk for Hashimoto's thyroiditis and Graves' disease increases with the number of risk alleles (OR for two risk alleles is, respectively, 2.27 and 2.59).

CONCLUSIONS

This study reports significant associations of genetic variants in TNFA and IL6 with the risk for AITD, highlighting the relevance of polymorphisms in inflammation-related genes in the etiopathogenesis of AITD.

The tyrosine kinase receptor c-met, its cognate ligand HGF and the tyrosine kinase receptor trasducers STAT3, PI3K and RHO in thyroid nodules associated with Hashimoto's thyroiditis: an immunohistochemical characterization

Hepatocyte growth factor (HGF) exerts proliferative activities in thyrocytes upon binding to its tyrosine kinase receptor c-met and is also expressed in benign thyroid nodules as well as in Hashimoto's thyroiditis (HT). The simultaneous expression of HGF/c-met and three trasducers of tyrosine kinase receptors (STAT3, PI3K, RHO) in both the nodular and extranodular tissues were studied by immunohistochemistry in 50 benign thyroid nodules (NGs), 25 of which associated with HT. The ligand/tyrosine kinase receptor pair HGF/c-met and the two trasducers PI3K and RHO were expressed in NGs, regardless of association with HT, with a higher positive cases percentage in HT-associated NGs compared to not HT-associated NGs (25/25 or 100% vs 7/25 or 28%; P<0.001). HGF, PI3K and RHO expression was only stromal (fibroblasts and endothelial cells), in all 32 reactive NGs, while c-met localization was consistently epithelial (thyrocyes). Immunoreactions for HGF, c-met, PI3K and RHO were also apparent in the extra-nodular tissue of HT specimens, where HGF and PI3K were expressed not only in stromal cells but also in thyrocyes along with the c-met. Finally, a positive correlation was observed between the proportion of HGF, c-met, PI3K follicular cells and the grade of lymphoid aggregates in HT. In conclusion, HGF, c-met, PI3K are much more frequently and highly expressed in HT compared to NGs, and among all NGs in those present in the context of HT. A paracrine effect of HFG/c-met on nodule development, based on the prevalent stromal expression, may be suggested along with a major role of HGF/c-met and PI3K in HT. Finally, the expression of such molecules in HT may be regulated by lymphoid infiltrate.