Experimental Autoimmune Thyroiditis Research Articles

Puerarin Alleviates Experimental Autoimmune Thyroiditis by Regulating Macrophages.

Hashimoto's thyroiditis (HT) is the most common organ-specific autoimmune disease, predominantly affecting women. Although the pathogenesis of HT is incompletely understood, some studies have found that macrophage polarization plays a role. Puerarin is a soy isoflavone compound that has anti-inflammatory and immunomodulatory effects and regulates macrophage immune activity. This study aimed to verify the therapeutic effect of puerarin on HT and explored its regulatory effect on macrophage polarization imbalance in HT. Through bioinformatics analysis and molecular biology methods, it was found that macrophages increased significantly in HT patients and model mice. Immunological staining showed that puerarin intervention could reduce tissue inflammatory cell infiltration. Molecular biological examination displayed that puerarin could inhibit local and systemic inflammation levels, and the expression of marker thyroglobulin and thyroid peroxidase Abs. In vivo experimental results indicated that puerarin regulated macrophage polarity and reduced inflammatory damage, possibly by inhibiting the pyroptosis signaling pathway. In vivo macrophage clearance experiments demonstrated that puerarin relied on macrophages to exert its mechanism of action in treating HT. The results of this study indicate that macrophages are important mediators in the development of HT, and puerarin can regulate macrophage polarity and inflammatory status to provide thyroid tissue protection, which provides a new idea for the treatment of HT.

Protective effect of thyroid and restores of ovarian function of Buzhong Yiqi granule on experimental autoimmune thyroiditis in female rats.

To observe the effects of Buzhong Yiqi granule on thyroid function and ovarian function in rats with experimental autoimmune thyroiditis (EAT). EAT model was replicate by using the method of mixing and injecting porcine thyroglobulin with Freund's adjuvant and high iodine. Rats were randomly divided into normal control (NC) group, EAT model (EAT) group, selenium yeast (PC) group, low dose Buzhong Yiqi (BZYQ-L) group, medium dose Buzhong Yiqi (BZYQ-M) group and high dose Buzhong Yiqi (BZYQ-H) group. After two months of drug intervention according to dosage, enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), anti-thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TGAb) in peripheral blood of rats. The pathological changes of rat thyroid tissues were observed under light microscope with HE staining; ELISA was used to determine estradiol (E2), follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), anti-müllerian hormone (AMH), and the pathological changes of rat ovarian tissues were observed under light microscope with hematoxylin and eosin staining. Compared with the NC group, BZYQ granule improved the thyroid and ovarian tissue morphology, and the levels of TPOAb, TGAb and TSH in the model group rats significantly increased (P < 0.05), the thyroid tissue was severely destroyed, the levels of E2, FSH, LH, T, AMH significantly increased (P < 0.05), and the ovary exhibited polycystic changes; Compared with the model group, TSH level in the BZYQ-L group rats decreased (P < 0.05), FSH, T, AMH levels decreased (P < 0.05), in the BZYQ-M group TPOAb, TSH levels decreased (P < 0.05), FSH, LH, T, AMH levels significantly decreased (P < 0.05), BZYQ-H group TPOAb, TGAb, TSH levels significantly decreased (P < 0.05), FSH, LH, T, AMH levels significantly decreased (P < 0.05), with the greatest improvement and significantly better than selenium yeast group (P < 0.05). BZYQ granule could regulate the thyroid function of EAT rats, reduce thyroid antibody titers, then act on the ovarian function, regulate hormone disorders, and alleviate the pathological damage of rat's ovarian tissues. The effect of high dose Buzhong Yiqi granule is the best.

The Effect of Simvastatin on Thyroid Function in Experimental Autoimmune Thyroiditis Induced in Rats

Autoimmune thyroiditis or Hashimoto’s thyroiditis (HT): is the most common autoimmune thyroid disease. is characterized by marked lymphocytic infiltration and the presence of serum autoantibodies against Thyroid peroxidase (TPO) and Thyroglobulin (TG). HT is a prevalent cause of hypothyroidism in areas of the world where dietary iodine is sufficient. Genetic predisposition and cellular and humoral immunity play a role in thyroid autoimmune pathogenesis. Antithyroid antibodies are produced by interaction between APC, T cells, and B cells to fix complement. Thyroid tissue is more severely damaged by complement-dependent antibody-mediated cytotoxicity. Statins, the powerful inhibitors of HMG-CoA reductase have pleotropic effects including anti-inflammatory and immunomodulatory effects. In this current study, Experimental autoimmune thyroiditis was induced in twenty-four female Wistar rat. Simvastatin was given at a dose of 4mg/kg for 30 days. Thyroid autoantibodies and Thyroid hormones were measured by ELISA technique Results showed that Simvastatin reduced autoantibodies against TPO and TG. It also lowered serum level of TSH and increased serum level of T4. Due to the undesirable side effects associated with the current treatment options used in Autoimmune thyroiditis. Simvastatin might be a promising approach in the treatment of this disease.

Content of macro- and microelements in rats with experimental autoimmune thyroiditis and under the influence of lemna minor

The aim was to study the effect of aqueous extract and 30 % alcohol tincture of Lemna minor frond (AELM and TLM) on the content of macro- and microelements in rats with experimental autoimmune thyroiditis. Materials and methods. The effect of AELM and TLM was studied in a model of experimental autoimmune thyroiditis in rats, induced by immunization with human thyroid antigen. The serum levels of total thyroxine, total triiodothyronine, antibodies to thyroglobulin, antibodies to thyroperoxidase, and concentrations of macro- and microelements were studied. Results. The development of experimental autoimmune thyroiditis led to a decrease in the content of total thyroxine and antibodies to thyroperoxidase in the blood serum, an increase in the content of antibodies to thyroglobulin and a decrease in the concentrations of sodium, chlorine, potassium phosphorus, zinc, copper, iron and magnesium. It was found that the use of AELM and TLM against the background of autoimmune thyroiditis led to the restoration of T4 and elemental balance in rats, which was manifested in an increase in the content of sodium, chlorine, phosphorus, magnesium, zinc, iron, copper and calcium in the blood serum. It was also shown that TLM had a more powerful effect on the normalisation of the content of such elements as chlorine, potassium, copper and zinc. The obtained effect of AELM and TLM on the content of macro- and microelements in the blood serum of animals with experimental AIT can be explained by their positive effect on the functional activity of the thyroid gland. The studied extract and tincture may also affect other physiological and biochemical processes due to the content of macro- and microelements and other biologically active substances, which requires further research. Conclusions. Administration of AELM and TLM to rats with experimental AIT contributed to lowering the level of Anti-TG and restoring the thyroid and elemental status in the animals' blood serum. The obtained research data allow us to recommend AELM and TLM as a regulator of the elemental status of the body in case of changes in thyroid function

A Flexible Mouse Model of Autoimmune Thyroiditis Induced by Immunization with an Adenovirus Containing Full-Length Thyroglobulin cDNA.

The main challenge in the "post-GWAS" era is to determine the functional meaning of genetic variants and their contribution to disease pathogenesis. Development of suitable mouse models is critical because disease susceptibility is triggered by complex interactions between genetic, epigenetic, and environmental factors that cannot be modeled by in vitro models. Thyroglobulin (TG) is a key gene for autoimmune thyroid disease (AITD) and several single nucleotide polymorphisms (SNPs) in the TG coding region have been associated with AITD. The classical model of experimental autoimmune thyroiditis (EAT), based on immunization of genetically susceptible mouse strains with purified TG protein in adjuvant, does not allow testing the impact of TG sequence variants on the development of autoimmune thyroiditis. Here we describe a protocol for the induction of EAT by immunization of mice susceptible to thyroiditis with an adenovirus vector carrying full-length human TG cDNA (Ad-TG EAT). We also provide support protocols for evaluation of autoimmune thyroiditis including serological assessment of TG antibodies, in vitro splenocyte proliferation assay and cytokines secretion, thyroid histology, and evaluation of thyroid lymphocytic infiltration by immunostaining. This protocol for EAT induction allows manipulation of the TG cDNA to introduce variants associated with AITD, enabling the testing of the functional effects of susceptible variants and their haplotypes on the immunogenicity of TG. Furthermore, the Ad-TG EAT mouse model is a valuable model for studying the interactions of the TG variants with non-genetic factors influencing AITD development (e.g., cytokines, iodine exposure) or with variants of other susceptible genes (e.g., HLA-DRβ1). © 2024 Wiley Periodicals LLC. Basic Protocol: Development of a mouse model of autoimmune thyroiditis induced by immunization with adenovirus containing full-length thyroglobulin cDNA Support Protocol 1: Splenocytes isolation Support Protocol 2: T cell stimulation and carboxyfluorescein diacetate succinimidyl ester (CFSE) based cell proliferation assay Support Protocol 3: Cytokine assays: measuring levels of interferon gamma (IFNγ) and interleukins IL-2, IL-4, and IL-10 in splenocyte supernatants Support Protocol 4: Evaluating thyroid histology and infiltration with immune cells: hematoxylin-eosin staining of mice thyroid glands Support Protocol 5: Immunohistochemistry of thyroid tissues: Immunofluorescence protocol of paraffin-embedded thyroid sections Support Protocol 6: Anti-thyroglobulin antibody measurement in mice sera by enzyme-linked immunosorbent assay (ELISA).

Notch signaling regulates Th17 cells differentiation through PI3K/AKT/mTORC1 pathway and involves in the thyroid injury of autoimmune thyroiditis.

Autoimmune Thyroiditis (AIT) is the most common thyroid disease; however, there were no measures to prevent the progression of the disease. The present study attempts to identify that Notch signaling regulates the differentiation of T helper 17 (Th17) cells by activating downstream Phosphatidylinositol-3 kinase/protein kinase/mechanistic target of rapamycin complex 1 (PI3K/AKT/mTORC1) pathway participating in the thyroid injury of the experimental autoimmune thyroiditis (EAT). In vivo experiments, mice were randomly divided into 4 groups: a control group, an EAT group, and two groups with LY294002 treatment (pTg plus 25mg/kg or 50mg/kg LY294002, respectively). The degrees of thyroiditis were evaluated, and the percentage of Th17 cells, expression of interleukin-17A (IL-17A), and the main components of the Notch-PI3K signaling pathway were detected in different groups. In vitro experiments, two different dosages of LY294002 (25 and 50μM) were used to intervene splenic mononuclear cells (SMCs) from EAT mice to further evaluate the regulatory effect of Notch-PI3K pathway on Th17 cells. Our data demonstrate that the infiltration of Th17 cells and the expressions of IL-17A, Notch, hairy and split 1 (Hes1), p‑AKT (Ser473), p‑AKT (Thr308), p‑mTOR (Ser2448), S6K1, and S6K2 increased remarkably in EAT mice. After PI3K pathway was blocked, the degrees of thyroiditis were significantly alleviated, and the proportion of Th17 cells, the expression of IL-17A, and the above Notch-PI3K pathway-related molecules decreased in a dose-dependent manner. Additionally, the proportion of Th17 cells was positively correlated with the concentration of serum thyroglobulin antibody (TgAb), IL-17A, and Notch-PI3K pathway-related molecules mRNA levels. Notch signal promotes the secretion of IL-17A from Th17 cells by regulating the downstream PI3K/AKT/mTORC1 pathway through Hes-Phosphatase and tensin homolog (PTEN) and participates in thyroid autoimmune damage, and the PI3K pathway inhibitor may play important effects on AIT by affecting Th17 cells differentiation.

Yiqi Jiedu Xiaoying Decoction Improves Experimental Autoimmune Thyroiditis in Rats by Regulating Th17/Treg Cell Balance.

Experimental autoimmune thyroiditis (EAT) is a widely used animal model to study the pathogenesis and treatment of autoimmune thyroid diseases. Yiqi Jiedu Xiaoying Decoction (YJXD) is a traditional Chinese medicine formula with potential immunomodulatory effects. In this study, we investigated the therapeutic effects of YJXD on EAT in rats and explored its underlying mechanisms. Female Wistar rats were induced to develop EAT by immunization with thyroglobulin (Tg) and taken sodium iodide water (0.05%) and then treated with YJXD or sodium selenite. HE staining was used to observe the pathological changes of thyroid tissue in EAT rats. Th17 and Treg cell frequencies were analyzed by flow cytometry, and the expression levels of Th17- and Treg-related cytokines and thyroid autoantibody were determined by enzyme-linked immunosorbent assay (ELISA). The expression of Th17- and Treg-related transcriptional factors was detected by real-time polymerase chain reaction (RT-PCR) and Immunohistochemistry (IHC). Our results demonstrated that treatment with YJXD significantly attenuated the severity of EAT, as evidenced by reduced thyroid gland inflammatory infiltration and decreased serum thyroglobulin autoantibody levels. Importantly, YJXD treatment effectively modulated the Th17/Treg cell balance by suppressing Th17 cell differentiation and promoting Treg cell expansion. Moreover, YJXD was also found to regulate the expression levels of Th17- and Tregrelated cytokines and transcriptional factors, further supporting its immunomodulatory effects in EAT. YJXD exerted therapeutic effects on EAT by regulating the Th17/Treg cell balance, modulating the production of Th17- and Treg-related cytokines and the expression of transcriptional factors.

Experimental rat models for Hashimoto's thyroiditis.

Hashimoto's thyroiditis (HT) is an autoimmune thyroid disease characterized by T lymphocyte-mediated destruction of thyroid follicles. To study the pathogenesis of HT and the efficacy of new substances for its treatment, an easily obtained and adequate to the human disease experimental model is needed. The aim of our study was to find out whether it is possible to induce experimental autoimmune thyroiditis (EAT) similar to Hashimoto's thyroiditis by injecting with thyroglobulin (Tg) without using agents that enhance its thyroiditogenicity and without taking into account the genetic sensitivity of animals. Wistar rats were immunized with freshly isolated rat Tg or porcine Tg. In 8weeks, histological studies of the thyroid and parathyroid glands were performed. Thyroid function and total serum calcium level were also evaluated. Immunization with both rat and porcine freshly isolated Tg caused T lymphocytic infiltration of the thyroid gland, thyroid follicle atrophy and degradation in Wistar rats. EAT caused by porcine Tg was characterized by greater severity than EAT induced with rat Tg. In 55% of rats with porcine Tg-induced EAT, oxyphilic metaplasia was detected in the parathyroid glands. In addition, low total serum calcium was observed in these rats. Two rat models of autoimmune thyroiditis were obtained. EAT caused in Wistar rats by immunization with rat Tg is similar to Hashimoto's thyroiditis. EAT induced with porcine Tg was accompanied by oxyphil cell metaplasia in the parathyroids and hypocalcemia.

Gut Microecology May Be Involved in the Pathogenesis of Hashimoto Thyroiditis by Reducing Production of Hydrogen Sulfide.

Hashimoto thyroiditis (HT) is related to intestinal microbiota alteration, but the causal relationship remains unclear. Hydrogen sulfide (H2S) is a microbiota-derived metabolite. We speculated that abnormal intestinal microbiota might limit H2S production capacity, promoting HT pathogenesis. This work aimed to illustrate that the intestinal microbiota plays important roles in HT pathogenesis via microbiota-derived H2S levels. We collected feces from HT patients and healthy donors for fecal microbiota transplantation (FMT). Thirty-six female CBA/J mice were randomly assigned to 4 groups: experimental autoimmune thyroiditis (EAT) group, EAT + Healthy group, EAT + HT group, and EAT + HT + H2S group. 16S ribosomal RNA sequencing was performed to examine gut microbiota alterations and the H2S production pathway. Serum TgAb and H2S levels were assayed by enzyme-linked immunosorbent assay and H2S-selective sensors, respectively. T-cell subpopulations in the spleen were detected by flow cytometry. The gut microbiota was different after FMT among the EAT, EAT + Healthy, and EAT + HT groups. The thyroiditis score assessed by hematoxylin and eosin staining was higher in the EAT + HT group than that in the EAT and EAT + HT + H2S groups. Helper T (Th1) and Th17 cell differentiation ratios were increased in the EAT + HT group compared to the other 3 groups. Serum H2S levels were decreased and the dissimilatory sulfate reduction (DSR) pathway was attenuated in the EAT + HT group compared to the EAT + Healthy group. H2S alleviated thyroiditis severity and related immune disorders, which were aggravated by the FMT from HT patients. The attenuated DSR pathway in the gut microbiota from HT patients might be involved in thyroiditis pathogenesis.

Selenium regulates T cell differentiation in experimental autoimmune thyroiditis in mice

Selenium (Se) is an essential trace element that plays an important role in thyroid physiology. Se supplementation can reduce levels of autoimmune thyroid antibodies, which may be beneficial in Hashimoto's thyroiditis (HT). However, the long-term benefits of Se supplementation for HT patients are controversial and there is no clear clinical evidence to support it, so further basic and clinical research is needed. The effect of Se on immune cells, especially T cells, in autoimmune thyroiditis (AIT) has not been elucidated. Here, we replicated a mouse model of experimental autoimmune thyroiditis (EAT) on a high-iodine diet and treated it with Se supplementation. At week 8 of the experiment, Se supplementation reduced the destruction of thyroid follicles and the infiltration rate of lymphocytes in EAT mice, and reversed the disturbance of peripheral blood thyroxine and thyroid autoantibody levels. Further examination revealed that Se had broad effects on T-cell subsets. Its effects include reducing the production of pro-inflammatory cytokines by Th1 cells, inhibiting the differentiation and production of cytokines by Th2 and Th17 cells, and upregulating the differentiation and production of cytokines by Treg cells. These changes help alleviate thyroid follicle damage during EAT. In conclusion, selenium supplementation has the potential to improve the prognosis of AIT by altering the subset differentiation and/or function of CD4+ T cells.

Circadian clock disruption in autoimmune thyroiditis.

A vicious cycle between circadian disruption and escalating immune responses has been described in diverse inflammatory disease. The current study aimed to explore the role of circadian clock disruption in autoimmune thyroiditis (AIT). Thirty AIT patients and 30 controls were enrolled and biopsied for thyroid tissues. Alterations of core clock genes expression in AIT thyroid tissues, and its association with serum and tissue inflammatory biomarkers were assessed. For animal studies, C57BL/6J mice administered with porcine thyroglobulin or PBS (as control) combined with adjuvants were sacrificed at four time points to investigate the circadian characteristic of experimental autoimmune thyroiditis (EAT). Light shift (LS) conditions were used to explore the influence of external circadian disturbance on EAT. The expression of clock genes BMAL1 and PER2 was significantly reduced in thyroid tissues from AIT patients and was negatively correlated to levels of thyroid peroxidase antibodies. In mouse models, diurnal fluctuations of proinflammatory cytokines were demonstrated, and further exposing mice to LS led to overproduction of TNF-α, IFN-γ, and anti-thyroglobulin antibodies. Circadian analysis revealed significant oscillations of Bmal1, Clock, Per2, Cry1, Ror, and Rev-erb, which was broadly disturbed in EAT, LS, and EAT + LS groups. This study demonstrates that expression pattern of clock genes was disrupted in AIT thyroid, and chronic circadian disruption may aggravate the inflammatory responses in AIT. Whether maintaining a regular circadian rhythm can alleviate autoimmune thyroid diseases warrants further research.

Effective Inhibition of Thyroid Antigen Presentation Using Retro-Inverso Peptides in Experimental Autoimmune Thyroiditis: A Pathway Toward Immune Therapies of Thyroid Autoimmunity.

Background: Autoimmune thyroid diseases (AITD) represent the most common autoimmune diseases. However, current therapies focus on relieving the symptoms instead of curing AITD, and new therapies to reverse the autoimmune attack on the thyroid are needed. HLA-DRβ1-Arg74 is the key HLA class II allele that triggers AITD by presenting pathogenic thyroglobulin (Tg) peptides that activate thyroid self-reactive T cells. We hypothesized that blocking the presentation of Tg peptides to T cells within the HLA-DRβ1-Arg74 peptide binding cleft could reverse the autoimmune response to the thyroid in AITD. Methods: The approach we used to block Tg peptide presentation within HLA-DRβ1-Arg74 is to design retro-inverso D-amino acid (RID) peptides that have high affinity to the HLA-DRβ1-Arg74 peptide binding pocket. Results: By using computational approaches and molecular dynamics simulations, we designed two RID peptides, RT-15 and VT-15, that blocked peptide binding to recombinant HLA-DRβ1-Arg74 molecule, as well as T cell activation in vitro. Furthermore, RT-15 and VT-15 blocked in vivo T cell activation by thyroglobulin in humanized NOD-DR3 mice induced with experimental autoimmune thyroiditis. Conclusions: In summary, we discovered two RID peptides that block thyroglobulin peptide binding to HLA-DRβ1-Arg74 and their presentation to T cells in AITD. These findings set the stage for a personalized medicine therapeutic approach for AITD patients who carry the DRβ1-Arg74 allele. This antigen-specific therapeutic strategy can potentially be extended to other autoimmune diseases.

Generation of a Mouse Spontaneous Autoimmune Thyroiditis Model.

In recent years, Hashimoto's thyroiditis (HT) has become the most common autoimmune thyroid disease. It is characterized by lymphocyte infiltration and the detection of specific serum autoantibodies. Although the potential mechanism is still not clear, the risk of Hashimoto's thyroiditis is related to genetic and environmental factors. At present, there are several types of models of autoimmune thyroiditis, including experimental autoimmune thyroiditis (EAT) and spontaneous autoimmune thyroiditis (SAT). EAT in mice is a common model for HT, which is immunized with lipopolysaccharide (LPS) combined with thyroglobulin (Tg) or supplemented with complete Freund's adjuvant (CFA). The EAT mouse model is widely established in many types of mice. However, the disease progression is more likely associated with the Tg antibody response, which may vary in different experiments. SAT is also widely used in the study of HT in the NOD.H-2h4 mouse. The NOD.H2h4 mouse is a new strain obtained from the cross of the nonobese diabetic (NOD) mouse with the B10.A(4R), which is significantly induced for HT with or without feeding iodine. During the induction, the NOD.H-2h4 mouse has a high level of TgAb accompanied by lymphocyte infiltration in the thyroid follicular tissue. However, for this type of mouse model, there are few studies to comprehensively evaluate the pathological process during the induction of iodine. A SAT mouse model for HT research is established in this study, and the pathologic changing process is evaluated after a long period of iodine induction. Through this model, researchers can better understand the pathological development of HT and screen new treatment methods for HT.

Dynamic changes in the histomorphological structure of the thyroid gland of rats against the background of experimental autoimmune thyroiditis

In preclinical studies, which are conducted to study the therapeutic effectiveness and pharmacological safety of biologically active compounds for the correction of autoimmune thyroiditis, various experimental models of this pathology are used in the experiment.&#x0D; In this work, we analyzed various models of thyroiditis that have been used for the past fifty years. Such an analysis made it possible to choose the most optimal model for the study of autoimmune pathology of the thyroid gland as well as for the correction of this condition. The analysis of known and the search for new pathogenetically justified models of autoimmune diseases of endocrine organs is a very urgent task.&#x0D; The aim of the work was to study the dynamics of changes in the histomorphological structure of the thyroid gland when modeling autoimmune thyroiditis in rats using an allogeneic antigen isolated from the human thyroid gland.&#x0D; The postoperative thyroid gland of a person was used as an antigen. Morphological changes in the thyroid gland were studied one, three and six months after the end of the simulation.&#x0D; It was found that the use of this type of immunization led to changes in the parenchyma of the gland, characteristic of autoimmune thyroiditis. Already one month after modeling, Gürtle cells, fibrosis, areas of lymphoid infiltration of the parenchyma were registered. These pathological changes persisted and worsened three and six months after the end of the simulation.&#x0D; The investigated type of model of experimental autoimmune thyroiditis is easily reproduced. Pathological changes in the gland deepen over time and are comparable to those that occur in people with Hashimoto's thyroiditis

Pharmacological suppression of NLRP3 inflammasome attenuated the development of autoimmune thyroiditis.

Autoimmune thyroiditis (AIT), characterized by an endless inflammatory process of self-destruction, ultimately leads to chronic swelling of the thyroid gland and its dysfunction. Here, we investigated the involvement of the NLR pyrin domain-containing 3 (NLRP3) inflammasome in AIT development. We found that NLRP3 is significantly upregulated in the thyroid of AIT patients and mice with experimental autoimmune thyroiditis (EAT). Pharmacological suppression of NLRP3 using its inhibitor MCC950 suppressed the progression of EAT in vivo. Furthermore, MCC950 treatment significantly reduced the numbers of infiltrating CD4+ and CD8+ T cells in the thyroid. Moreover, MCC950 significantly lowered the amounts of T helper 1 cells, T helper 17 cells, interferon gamma, and interleukin-17A; however, it significantly increased regulatory-T-cell numbers and interleukin-10 levels. These results suggest that suppression of NLRP3 inflammasome activation reverses AIT by inhibiting Th1- and Th17-cell responses and promoting Treg cell responses. Hence, the NLRP3 inflammasome is a promising therapeutic and theragnostic target in AIT. inhibits Th1- and Th17-cell responses and promotes Treg cell responses.

Notch Signaling Pathway Promotes Th17 Cell Differentiation and Participates in Thyroid Autoimmune Injury in Experimental Autoimmune Thyroiditis Mice.

To investigate whether the Notch signaling pathway participates in the occurrence and development of experimental autoimmune thyroiditis (EAT) by affecting the differentiation and function of Th17 cells. Experimental mice were randomly divided into a control group, an EAT-A group (porcine thyroid immunoglobulin- (pTg-) treated mice) and an EAT-B group (treated with the DAPT γ-secretase inhibitor before pTg). HE staining, IHC staining, flow cytometry, RT-qPCR, and ELISA were used to evaluate the degrees of thyroiditis, detect the percentage of Th17 cells and measure the expression of retinoic acid-related orphan receptor gamma t (RORγt), interleukin-17A (IL-17A), and the main components of the Notch signaling pathway. The degrees of thyroiditis, the proportions of Th17 cells, and the expression of RORγt and IL-17A were significantly decreased in the EAT-B group after blocking the Notch signaling pathway by DAPT, and these parameters were significantly increased in the EAT-A group compared to the control group (all P < 0.05). Additionally, the Th17 cell percentages and IL-17A concentrations in spleen mononuclear cells (SMCs) from EAT-A mice decreased in a dose-dependent manner after DAPT treatment in vitro (all P < 0.01). Correlation analyses revealed that the Th17 cell percentages were positively correlated with the serum TgAb titers, Notch pathway-related mRNA expression levels, and IL-17A concentrations in EAT mice (all P < 0.05). The expression of Notch signaling pathway components was upregulated in EAT mice, but blockade of the Notch signaling pathway alleviated the degree of thyroiditis, decreased the Th17 cell proportions, and downregulated the IL-17A effector cytokine both in vivo and in vitro. These findings suggested that the Notch signaling pathway may be involved in the pathogenesis of thyroid autoimmune injury in EAT mice by promoting the differentiation of Th17 cells.

Determination of the Predictive Roles and Potentially Pathogenic Antigen Epitopes of α-Enolase Related to the Development of Miscarriage in Females with Autoimmune Thyroiditis.

Autoimmune thyroiditis (AIT) is a common endocrine disease which causes a significantly increased risk of miscarriage. Our recent study has shown that the increased ENO1 autoantibody (ENO1Ab) expression in an experimental AIT mouse model was induced by thyroglobulin (Tg) immunization only. In this study, we explored the potential roles of ENO1Ab in miscarriage occurrence among AIT women, and the specific epitopes of ENO1 targeted by ENO1Ab. A total of 432 euthyroid pregnant participants were selected from the project of Subclinical Hypothyroid during Early Pregnancy, including 48 women with AIT and miscarriage, 96 with miscarriage but no AIT, 96 with AIT but no miscarriage, and 192 without either AIT or miscarriage. The enzyme-linked immunosorbent assay was used to determine the serum levels of total IgG against ENO1 and 18 predicted antigen epitopes of ENO1. The results showed that women with AIT and miscarriage had the highest serum levels of ENO1Ab compared to the other groups. Logistic regression analysis showed that the serum ENO1Ab was an independent risk factor for miscarriage, especially among AIT females. The serum level of total IgG against the predicted epitope peptide 6 (i.e., P6 and aa168-183) of ENO1 was significantly increased in women with AIT and miscarriage when compared with those of both the AIT non-miscarriage group and non-AIT miscarriage group. This pilot study suggests that serum ENO1Ab may have a fair predictive value for AIT-related miscarriage, and the autoantibody specific to P6 epitope may especially be more specifically related to this disorder.

Effects of herbal cake-partitioned moxibustion on the expression of thyroid autophagy-related factors LC3B and Beclin-1 in rats with autoimmune thyroiditis

ObjectiveTo observe the anti-inflammatory effect, as well as the effect on the expression of microtubule-associated protein light chain 3B (LC3B) and Beclin-1 of herbal cake-partitioned moxibustion in rats with experimental autoimmune thyroiditis (EAT).MethodsFemale Sprague-Dawley rats were randomly divided into a normal group and a modeling group. The EAT rat model was prepared by a combination of antigen immunization plus iodine agent induction. After the model was prepared, rats in the modeling group were randomly and equally divided into a model group and a herbal cake-partitioned moxibustion group. In the herbal cake-partitioned moxibustion group, moxibustion was alternately applied to two groups of points [Dazhui (GV14)-Mingmen (GV4) and Tiantu (CV22)-Guanyuan (CV4)], and the treatment continued for 30 d. Rats in the normal and model groups were only fixed identically without intervention. Histopathological manifestations of thyroid glands were observed by hematoxylin-eosin staining; the concentrations of thyroid peroxidase antibodies (TPOAb), thyroglobulin antibodies (TGAb), interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay; real-time fluorescence quantitative polymerase chain reaction and immunohistochemistry were used to detect the mRNA and protein expression of autophagy-related factors LC3B and Beclin-1 in thyroid tissue.ResultsThere were massive follicular destruction, lymphocytic infiltration, and interstitial fibrous tissue hyperplasia of the thyroid glands in the model group. Some follicles of the thyroid glands were destroyed with few lymphocyte infiltrations and fibrous tissue hyperplasia in the moxibustion group. Compared with the normal group, the concentrations of serum TPOAb, TGAb, IL-1β, IL-6, and TNF-α were increased in the model rats (P<0.05); the mRNA and protein expression levels of LC3B and Beclin-1 in thyroid tissue were reduced in the model group (P<0.05). Compared with the model group, the concentrations of serum TPOAb, TGAb, IL-1β, IL-6, and TNF-α were reduced in the herbal cake-partitioned moxibustion group (P<0.05); the mRNA and protein expression levels of LC3B and Beclin-1 in thyroid tissue were increased in the herbal cake-partitioned moxibustion group (P<0.05). The mRNA and protein expression of LC3B and Beclin-1 in thyroid tissue was negatively correlated with the serum levels of TPOAb and TGAb.ConclusionHerbal cake-partitioned moxibustion reduces the inflammatory response in the thyroid glands of EAT rats and lowers the levels of serum TPOAb and TGAb. This may be related to the regulation of mRNA and protein expression of the autophagy-associated factors LC3B and Beclin-1 in rat thyroid tissue.

Reduction in experimental autoimmune thyroiditis by IgG Fc fragments bearing regRF epitopes.

Previously, we identified a new immunoregulatory factor, the production of which provides rats with resistance to certain experimental autoimmune diseases. It has been named regulatory rheumatoid factor (regRF). RegRF inhibits the expansion of CD4 T lymphocytes by killing activated cells. CD4 T cells are essential for antibody production against a majority of antigens and for the generation of cytotoxic T cells; therefore, regRF is an attractive therapeutic biotarget for T-cell and antibody-mediated autoimmune diseases. RegRF is anti-idiotypic antibodies that have a shared paratope in addition to an individual paratope. Epitopes specific to the shared regRF paratope (regRF epitopes) can be obtained on conformers of IgG Fc fragments. Immunization with Fc fragments carrying regRF epitopes reduces rat collagen-induced arthritis and diminishes experimental autoimmune encephalomyelitis. The aim of this study was to determine whether IgG Fc fragments bearing regRF epitopes suppress experimental autoimmune thyroiditis (EAT). Four weeks after EAT induction, rats were immunized with IgG Fc fragments exhibiting regRF epitopes. Histology studies of the thyroid were performed 4weeks later. Thyroid function and other parameters were also evaluated. Treatment of rats with Fc fragments bearing regRF epitopes decreased the number of rats affected by EAT, significantly decreased the extent of thyroid damage, prevented thyroid metaplasia, and restored normal thyroid hormone production. Therefore, RegRF is a promising biotarget in autoimmune thyroiditis, and Fc fragments bearing regRF epitopes are a potential therapeutic agent for that condition.

Leptin receptor antagonist attenuates experimental autoimmune thyroiditis in mice by regulating Treg/Th17 cell differentiation.

Leptin has been found to be involved in the development and progression of many autoimmune diseases. As an organ-specific autoimmune disease, the pathogenesis of Hashimoto's thyroiditis has not been fully elucidated. It has been reported that serum leptin level is increased in Hashimoto's thyroiditis, but other studies have not shown any difference. We replicated a mouse model of experimental autoimmune thyroiditis (EAT) with a high-iodine diet and found that injection of the leptin receptor antagonist Allo-aca reduced thyroid follicle destruction and inflammatory cell infiltration in EAT mice, and thyroxine and thyroid autoimmune antibody levels. Further investigation revealed that Allo-aca promotes the differentiation of Treg cells and inhibits the differentiation of Th17 cells. We believe that Allo-aca can alter the differentiation of Treg/Th17 cells by inhibiting the leptin signaling pathway, thereby alleviating thyroid injury in EAT mice. Interfering with the leptin signaling pathway may be a novel new approach to treat treating and ameliorating Hashimoto's thyroiditis.