Determinants of thyroid autoantibody production in Hashimoto’s thyroiditis

Hashimoto’s thyroiditis (HT) is the most prevalent thyroid autoimmune disorder, characterized by the presence of specific thyroid autoantibodies (TAb). The development of autoimmunity, including TAb production and clinical presentation of HT, is determined by a complex interplay of genetic susceptibility and several endogenous and environmental factors, which are discussed in this article. During the progression of the disease, TAb production precedes clinical manifestations, although the correlation between TAb concentrations and thyroid function is weak. We do not treat euthyroid HT patients despite elevated TAb; while in hypothyroidism, replacement therapy with l-thyroxine is required. Until now, an effective approach to prevent TAb production and the development of clinical disease has not yet been established. However, further identification of risk factors and their interaction may help in the prevention of thyroid autoimmunity.     

Genistein improves thyroid function in Hashimoto’s thyroiditis patients through regulating Th1 cytokines

Hashimoto thyroiditis (HT) is a common autoimmune disease. Genistein is an isoflavone with immunomodulatory functions in various diseases. In this double-blind, randomized, placebo-controlled clinical study, we investigated the effects of genistein on patients with HT. A total of 218 patients were recruited. Genistein treated patients had a significant increased T₄, fT₄ levels, as well as reduction in serum TSH, TPOAb and TgAb levels, compared with those receiving placebo. Furthermore, Th1 related cytokine IFN-γ and IL-2 changes after genistein treatment suggest the immune modulating effect of genistein is mediated through regulating the function of Th1 cells. Overall, the genistein administration was effective and well tolerated in HT patients. These results demonstrate an immunological effect of genistein on HT patients. Further studies are warranted to determine the longer-term effects and possible chemopreventive effects on thyroid cancer in HT patients.     

Maltoma of the thyroid and Sjögren’s syndrome in a woman with Hashimoto’s thyroiditis

We report the case of a 70-yr-old woman with maltoma of the thyroid, Sjögren’s syndrome, and a history of Hashimoto’s thyroiditis. The patient underwent a total thyroidectomy for a recently growing mass of the thyroid, while being treated with l-thyroxine for Hashimoto’s thyroiditis. Postoperatively, routine histologic examination was consistent with the diagnosis of chronic lymphocytic thyroiditis of autoimmune etiology. Three years later, the patient presented with high temperature, anorexia, and coughing. This time, a microscopic examination of deeper thyroid tissue sections and an immunohistochemical study revealed a low-grade, non-Hodgkin lymphoma, MALT type. Simultaneously, the diagnosis of Sjögren’s syndrome was established and the patient is currently under investigation for generalized lymphoma. This case clearly demonstrates the difficulty in differentially diagnosing Hashimoto’s thyroiditis from low-grade MALT lymphoma by the use of routine histologic examination.     

Time of transplantation and cell preparation determine neural stem cell survival in a mouse model of Huntington’s disease

Cell replacement therapies for neurodegenerative diseases, using multipotent neural stem cells (NSCs), require above all, a good survival of the graft. In this study, we unilaterally injected quinolinic acid (QA) into the striatum of adult mice and transplanted syngeneic NSCs of enhanced green fluorescent protein-transgenic mice into the lesioned striatum. The injection of QA leads to an excitotoxic lesion with selective cell death of the medium sized spiny neurons, the same cells that are affected in Huntington’s disease. In order to investigate the best timing of transplantation for the survival of donor cells, we transplanted the stem cells at 2, 7 and 14 days after injury. In addition, the influence of graft preparation prior to transplantation, i.e., intact neurospheres versus dissociated cell suspension on graft survival was investigated. By far the best survival was found with the combination of early transplantation (i.e., 2 days after QA-lesion) with the use of neurospheres instead of dissociated cell suspension. This might be due to the different states of host’s astrocytic and microglia activation which we found to be moderate at 2, but pronounced at 7 and 14 days after QA-lesion. We also investigated brain derived neurotrophic factor (BDNF)-expression in the striatum after QA-lesion and found no significant change in BDNF protein-level. We conclude that already the method of graft preparation of NSCs for transplantation, as well as the timing of the transplantation procedure strongly affects the survival of the donor cells when grafted into the QA-lesioned striatum of adult mice.     

Frequency and Distribution of DNA fragmentation in Hashimoto’s thyroiditis and development of papillary thyroid carcinoma

Downregulation of apoptosis and high expression of bcl-2 play an important role in the development of follicular lymphoma. However, little is known about apoptosis in thyroid disease, particularly with respect to the development of papillary carcinoma from Hashimoto’s thyroiditis. To study the early stages of cell death in various types of thyroid disease, surgical specimens from 31 patients including Hashimoto’s thyroiditis (HT,n=7), papillary carcinoma (PC,n=12), Hashimoto’s thyroiditis with papillary carcinoma (HTPC,n=5), and Graves’ disease (GD,n=7) were examined by anin situ nucleotidyl transferase assay (ISNTA), which detects DNA fragmentation. Control normal thyroid tissue (NT,n=7) was obtained from surgically resected papillary thyroid carcinomas sampled away from the primary tumor. An immunohistochemical (IHC) method was used to detect bcl-2 expression. Positive ISNTA nuclei in thyroid follicular cells or tumor cells per section were counted in all parenchymal areas, excluding areas of lymphocyte aggregates. The intensity of bcl-2 staining was graded on a scale of 1+ to 3+. The number of ISNTA-positive thyroid follicular cells was a significantly higher in HT compared to GD. In addition, there was significantly lower number of ISNTA positive non-neoplastic thyroid follicular cells in HTPC compared to HT alone. Strong expression of bcl-2 was found in all cases of GD and NT, but much less bcl-2 staining was seen in HT. There was moderate expression of bcl-2 in HTPC and PC. These findings suggest that (1) DNA fragmentation of the thyroid follicular cells plays an important role in the thyroid injury in HT but not in GD, (2) expression of bcl-2 may overcome the apoptosis in GD but not in HT, and (3) downregulation of DNA fragmentation of the follicular cells in Hashimoto’s thyroiditis associated with papillary carcinoma may suggest an important mechanism for tumor pathogenesis.     

First surgical tumour reduction of peritoneal surface malignancy in a rat’s model

Surgical therapy of peritoneal surface malignancy from colorectal origin in combination with Hyperthermic Intraoperative Peritoneal Chemotherapy (HIPEC) has now become an established treatment approach in very few specialised centres. A peritonectomy procedure is possible to perform with additional HIPEC in patients. An experimental model to simulate peritonectomy procedure and HIPEC does not exist so far in rats. Nevertheless, animal models seem to be very important for evaluation of new therapeutic opportunities and toxicity of different multimodal therapies. In a first step we analysed the surgical tumour debulking of peritoneal surface malignancy in rats. A peritoneal surface malignancy from colonic origin was induced in 75 male BD IX rats. Twenty one days after induction of peritoneal surface malignancy rats were randomised and animals intend to create an operation with surgical tumour debulking. There was no tumour growth in two animals. The aim of the peritonectomy procedure was the complete tumour reduction. In this study the results of the surgical approach will be described. A complete tumour reduction (R0) was achieved in 34 animals. In 39 rats a macroscopic tumour deposit was left behind (R2). The intraoperative experimental Peritoneal Cancer Index (ePCI) was used to describe tumour weight and number of tumour inoculations. Both parameters were found to be dependent factors of complete tumour reduction. Six animals died due to therapeutical interventions. Surgical tumour debulking in rats with peritoneal surface malignancy is possible with high reliability and a low mortality rate. This animal model could be an important step for investigation of multimodal treatment options and toxicity in treatment regimens of peritoneal surface malignancy.     

Primary mediastinal large B-cell lymphoma arising from thyroid in a renal recipient with Hashimoto’s thyroiditis

Primary mediastinal large B-cell lymphoma is a subtype of diffuse large B-cell lymphoma, arising in the mediastinum from putative thymic B-cell origin with distinctive clinical and genetic features. Generally, primary mediastinal large B-cell lymphoma is believed as only deriving in the mediastinum. The current study presents a rare case of primary mediastinal large B-cell lymphoma which arising from thyroid in a renal recipient with Hashimoto’s thyroiditis. Moreover, we devoted a discussion to the relationship among primary mediastinal large B-cell lymphoma, immunomodulatory therapy and autoimmune diseases. The immunologic derangement induced by long-term immunomodulatory therapy and Hashimoto’s thyroiditis may be the possible cause for the ectopic lymphoma.     

Increased circulating Tfh17 and PD-1+Tfh cells are associated with autoantibodies in Hashimoto’s thyroiditis

Abstract

Objective: Hashimoto’s thyroiditis (HT) is characterized by autoantibodies targeting the thyroid. Abnormal CD4⁺CXCR5⁺T cell levels were previously shown to be associated with HT. However, Tfh cells consist of heterogeneous subpopulations, and which T follicular helper (Tfh) cell subpopulation participates in the pathogenesis of HT remains poorly understood.

Methods: Thirty healthy controls (HCs) and 52 HT patients were enrolled in the study. The percentages of Tfh, ICOS⁺Tfh, PD1⁺Tfh, Tfh1, Tfh2, Tfh17, effector Tfh, resting Tfh, effector memory Tfh, central memory Tfh, and naïve Tfh cells in the peripheral blood were all determined via flow cytometry, and the associations between the percentages of these cells and thyroid function indices were also investigated.

Results: The percentage of Tfh cells was significantly higher in HT patients than in HCs. Examination of the Tfh cell subsets revealed that the percentages of Tfh1, Tfh2, and resting Tfh cells were significantly decreased, while those of the ICOS⁺Tfh, PD1⁺Tfh, Tfh17, and effector Tfh cells were significantly increased in HT patients. No significant differences in effector memory, central memory or naïve Tfh cell percentages were noted between the HC and HT groups. Furthermore, the percentage of PD1⁺Tfh cells was positively correlated with anti-thyroglobulin antibody levels. Most importantly, only Tfh17 cell percentages were positively correlated with anti-thyroglobulin and anti-thyroid peroxidase antibody levels and were negatively correlated serum free T3 and free T4 levels in HT patients.

Conclusions: Increased circulating Tfh17 cell and PD1⁺Tfh percentages are associated with higher autoantibody levels in HT patients, which imply that Tfh17 or PD1⁺Tfh cells may play a pathogenic role in the development of HT.     

Long-term restoration of nigrostriatal system function by implanting GDNF genetically modified fibroblasts in a rat model of Parkinson’s disease

The motor behavior and levels of dopamine and its metabolites in the striatum were studied in rats that received a unilateral injection of 6-OHDA and underwent grafting of rat-derived primary fibroblasts that had been genetically modified to express lacZ and human glial cell line-derived neurotrophic factor (GDNF). Rotation behavior tests were performed each week and striatal levels of DA and its metabolites were measured every 4 weeks after grafting of fibroblasts that expressed lacZ, with or without additional transfection of the GDNF transgene. Rats grafted with GDNF-producing fibroblasts showed a significant improvement in motor behavior as determined by the rotation test, with a less pronounced reduction in the levels of dopamine and its metabolites in the striatum as compared with those in the control animals or brain parts. In addition, there was a lower decrease in the number of TH immunoreactive neurons in the substantia nigra ipsilateral to the lesion in rats with GDNF-producing fibroblasts than in rats with lacZ-expressing fibroblasts. These results support the notion that intracerebral grafting of fibroblasts that express GDNF is a potentially useful therapeutic strategy for treating Parkinsons disease.     

The effect of matrix stiffness on the differentiation of mesenchymal stem cells in response to TGF-β

Bone marrow mesenchymal stem cells (MSCs) are a valuable cell source for tissue engineering and regenerative medicine. Transforming growth factor β (TGF-β) can promote MSC differentiation into either smooth muscle cells (SMCs) or chondrogenic cells. Here we showed that the stiffness of cell adhesion substrates modulated these differential effects. MSCs on soft substrates had less spreading, fewer stress fibers and lower proliferation rate than MSCs on stiff substrates. MSCs on stiff substrates had higher expression of SMC markers α-actin and calponin-1; in contrast, MSCs on soft substrates had a higher expression of chondrogenic marker collagen-II and adipogenic marker lipoprotein lipase (LPL). TGF-β increased SMC marker expression on stiff substrates. However, TGF-β increased chondrogenic marker expression and suppressed adipogenic marker expression on soft substrates, while adipogenic medium and soft substrates induced adipogenic differentiation effectively. Rho GTPase was involved in the expression of all aforementioned lineage markers, but did not account for the differential effects of substrate stiffness. In addition, soft substrates did not significantly affect Rho activity, but inhibited Rho-induced stress fiber formation and α-actin assembly. Further analysis showed that MSCs on soft substrates had weaker cell adhesion, and that the suppression of cell adhesion strength mimicked the effects of soft substrates on the lineage marker expression. These results provide insights of how substrate stiffness differentially regulates stem cell differentiation, and have significant implications for the design of biomaterials with appropriate mechanical property for tissue regeneration.     

The cardiomyogenic differentiation of rat mesenchymal stem cells on silk fibroin–polysaccharide cardiac patches in vitro

Polysaccharides and proteins profoundly impact the development and growth of tissues in the natural extra-cellular matrix (ECM). To mimic a natural ECM, polysaccharides were incorporated to/or co-sprayed with silk fibroin (SF) to produce SF/chitosan (CS) or SF/CS–hyaluronic acid (SF/CS–HA) microparticles that were further processed by mechanical pressing and genipin cross-linking to produce hybrid cardiac patches. The ATR–FTIR spectra confirm the co-existence of CS or CS–HA and SF in microparticles and patches. For evaluating the cellular responses of rMSCs to the SF/CS and SF/CS–HA cardiac patches, the growth of rMSCs and cardiomyogenic differentiation of 5-aza inducing rMSCs cultured on patches was examined. First, the isolated rMSCs were identified with various positive and negative surface markers such as CD 44 and CD 31 by a flow cytometric technique, respectively. For examining the growth of rMSCs on the patches, MTT viability assay was performed, and the results demonstrated that the growth of rMSCs on SF and SF-hybrid patches significantly exceeded (P < 0.001) that on culture wells after seven days of cultivation. Additionally, the relative growth rates of rMSCs on SF/CS and SF/CS–HA hybrid patches were significantly better (P < 0.01) than that on SF patches that were also observed by using vimentin stain to the cells. For instance, the relative cell growth rates (%) in cell culture wells, SF, SF/CS and SF/CS–HA patches were 100%, 282.9 ± 6.5%, 337.0 ± 8.0% and 332.6 ± 6.6% (n = 6, for all), respectively. For investigating the effects of the hybrid patches on cardiomyogenic differentiation of 5-aza inducing rMSCs, the expressions of specific cardiac genes of cells such as Gata4 and Nkx2.5 were examined by real-time quantitative polymerase chain reaction (real-time PCR) analysis. The results of cardiomyogenic differentiation of induced rMSCs on SF/CS and SF/CS–HA hybrid patches significantly improved the expressions of cardiac genes of Gata4, Nkx2.5, Tnnt2 and Actc1 genes (all, P < 0.01 or better, n = 3) than those on SF patches and culture wells. Interestingly, the results of cardiac gene expressions of the cells on the SF/CS–HA hybrid patches were the most pronounced in promoting cardiomyogenic differentiations in this investigation. Furthermore, immunofluorescence staining of cardiac proteins such as cardiotin and connexin 43 for induced rMSCs cultured on SF/CS and SF/CS–HA hybrid patches were much pronounced compared with SF patches, indicating the improvements of cardiomyogenic differentiation on the hybrid patches. The results of this study demonstrate that the SF/CS and SF/CS–HA hybrid patches may be promising biomaterials for regenerating infarcted cardiac tissues.     

Critical amino acid variants in HLA-DRB1 allotypes in the development of Graves’ disease and Hashimoto’s thyroiditis in the Japanese population

The effects of amino acid variants encoded by human leukocyte antigen (HLA) class II on the development of Graves’ disease (GD) and Hashimoto’s thyroiditis (HT) have not been fully elucidated. We investigated the HLA-DRB1 genes of 243 GD patients and 82 HT patients in the Japanese population and compared the frequencies of HLA-DRB1 alleles and HLA-DRB1 amino acid variants between these patients and the Japanese populations previously reported by another institution. The frequencies of HLA-DRB1*04:05 and -DRB1*14:03 alleles were significantly higher and those of HLA-DRB1*01:01 and -DRB1*15:02 alleles were lower in GD patients than in controls. The frequencies of HLA-DRB1*08:03 and -DRB1*09:01 alleles were significantly higher and that of the HLA-DRB1*13:02 allele was lower in HT patients than in controls. A blind association analysis with all amino acid positions identified DRß9 and DRß31 for GD and DRß9, DRß13, and DRß21 for HT. The frequency of Glu-9 was significantly higher and that of Cys-9 was lower in GD patients than in controls. The frequencies of Lys-9 and Phe-13 were significantly higher in HT patients than in controls. DRß9 and DRß13 could be critical amino acid positions in the development of GD and HT.     

Th17-Inducing Conditions Lead to in vitro Activation of Both Th17 and Th1 Responses in Behcet’s Disease

Objectives: Interleukin-17 (IL-17) has been associated with the pathogenesis of various autoimmune/inflammatory diseases. The aim of this study was to investigate the expression of Th17-related immunity in an innate immunity-dominated vasculitis, namely Behcet’s disease (BD).

Methods: Peripheral blood mononuclear cells from 37 patients (age: 38.5 ± 9.8 years) with BD, and 25 healthy controls (HC) (age: 39.1 ± 9.3 years), were cultured in Th17-inducing conditions (IL-6, Phytohemagglutinin (PHA), IL-1β, and IL-23) for 6 days. Cultured cells were stained with CD4, CD8, CD3, TCR gamma/delta, CD19, interferon-γ (IFN-γ), and IL-17 antibodies to determine the intracellular cytokine secretion by flow cytometry.

Results: IL-17 expression by CD8+ and γδ+ T cells was higher in BD compared to HC (p = 0.004, p = 0.003, respectively). No differences were observed between the groups in the IL-17 production by B cells. Under Th17-inducing conditions, production of IFN-γ by CD4+, CD8+, and γδ+ T cells was also higher in BD compared to HC (p < 0.05 in all).

Conclusion: Our results suggest that under Th17-stimulating conditions, T cells express both IL-17 and IFN-γ in BD. More prominent IL-17 and IFN-γ production by all lymphocyte subsets in BD might be associated with the increased innate responses, early tissue neutrophil infiltrations and late adaptive immunity in BD.     

Dual release of dexamethasone and TGF-β3 from polymeric microspheres for stem cell matrix accumulation in a rat disc degeneration model

Low back pain is frequently caused by nucleus pulposus (NP) degeneration. Tissue engineering is a powerful therapeutic strategy which could restore the normal biomechanical motion of the human spine. Previously we reported that a new nanostructured three-dimensional poly(lactide-co-glycolide) (PLGA) microsphere, which is loaded with dexamethasone and growth factor embedded heparin/poly(l-lysine) nanoparticles via a layer-by-layer system, was an effective cell carrier in vitro for NP tissue engineering. This study aimed to investigate whether the implantation of adipose-derived stem cell (ADSC)-seeded PLGA microspheres into the rat intervertebral disc could regenerate the degenerated disc. Changes in disc height by plain radiograph, T2-weighted signal intensity in magnetic resonance imaging (MRI), histology, immunohistochemistry and matrix-associated gene expression were evaluated in normal controls (NCs) (without operations), a degeneration control (DC) group (with needle puncture, injected only with Dulbecco’s modified Eagle’s medium), a PLGA microspheres (PMs) treatment group (with needle puncture, PLGA microspheres only injection), and PLGA microspheres loaded with ADSCs treatment (PMA) group (with needle puncture, PLGA microspheres loaded with ADSC injection) for a 24-week period. The results showed that at 24 weeks post-transplantation, the PM and PMA groups regained disc height values of ～63% and 76% and MRI signal intensities of ～47% and 76%, respectively, compared to the NC group. Biochemistry, immunohistochemistry and gene expression analysis also indicated the restoration of proteoglycan accumulation in the discs of the PM and PMA groups. However, there was almost no restoration of proteoglycan accumulation in the discs of the DC group compared with the PM and PMA groups. Taken together, these data suggest that ADSC-seeded PLGA microspheres could partly regenerate the degenerated disc in vivo after implantation into the rat degenerative intervertebral disc.     

The effect of collagen-binding NGF-β on the promotion of sciatic nerve regeneration in a rat sciatic nerve crush injury model

Nerve growth factor plays a critical role in peripheral nerve regeneration. However, the lack of efficient NGF delivery approach limits its clinical application. It has demonstrated in our previous work that the native human NGF-β (NAT-NGF) fused with a collagen-binding domain (CBD) could bind to collagen specifically. Since collagen is the major component of nerve extracellular matrix, we speculated that the collagen-binding NGF would target to nerve cells and improve their regeneration. In this report, we found that the fusion protein could specifically bind to endogenous collagen of the rat sciatic nerves and maintain NGF activity both in vitro and in vivo. In the rat sciatic nerve crush injury model, we found that collagen-binding NGF could be retained and concentrated at the nerve injured site to promote nerve repair and enhance function recovery following nerve damage. Thus, the collagen-binding NGF could improve the repair of peripheral nerve injury.     

Microarray profiling and functional analysis reveal the regulatory role of differentially expressed plasma circular RNAs in Hashimoto’s thyroiditis

Immunologic Research - Circular RNAs (circRNAs) have been revealed as being abundantly expressed in a variety of tissues and have been found to contribute to the regulation of many autoimmune...     

Modulus-dependent characteristics of Wharton’s jelly mesenchymal stem cells (WJMSC) encapsulated in hydrogel microspheres

Recent studies revealing stem cell behavior dependence on mechanical properties of a substrate has initiated the need to probe matrix mechanics and its influence on stem cell fate in a physiologically relevant three-dimensional (3D) microenvironment. We investigated the proliferative and osteogenic potentials of Wharton’s jelly mesenchymal stem cells (WJMSCs) immobilized in alginate microspheres with respect to the mechanical properties of alginate hydrogels (1, 1.5 and 2% (w/v)) post incubation in a simulated in vivo environment. Compressive moduli, degradation profile, and swelling kinetics of the hydrogels varied proportionally with alginate concentration and with exposure to simulated conditions. Degradation profile and morphological analysis showed that hydrogels exhibiting high modulus (2% w/v) remained the most intact at the end of day 21. High cell viability in all conditions was observed throughout the culture period. Low-modulus hydrogels (1% w/v) facilitated proliferation of WJMSCs whereas high-modulus hydrogels demonstrated better osteogenic differentiation inferred by an up regulation of osteo-specific genes, expressions of osteocalcin, and quantification of calcium deposition. These findings present a step forward in the development of application-specific hydrogel matrices for stem cell-based tissue engineering.