Interleukin-10 promotes resolution of granulomatous experimental autoimmune thyroiditis

Inbred Mouse Models in Cryptococcus neoformans Research

Animal models are frequently used as surrogates to understand human disease. In the fungal pathogen Cryptococcus species complex, several variations of a mouse model of disease were developed that recapitulate different aspects of human disease. These mouse models have been implemented using various inbred and outbred mouse backgrounds, many of which have genetic differences that can influence host response and disease outcome. In this review, we will discuss the most commonly used inbred mouse backgrounds in C. neoformans infection models.

Analysis of cytokine levels, T regulatory cells and serotonin content in patients with depression

Alterations in peripheral serotonin concentrations and an imbalanced immune system have been reported in patients with depression. Cytokines and T regulatory (Treg) cells may play an important role in the development of depression. This study investigates the levels of cytokines and Treg cells, as well as the concentration of serotonin (5-HT) in the blood of 89 patients suffering from depression and 89 healthy participants between two acquisitions. We investigated the state of health before (T1) and after (T2) psychological and pharmacological therapy. Both cytokine (IL-6, IL-10, TNF-α, and INF-γ) and 5-HT levels in the blood were measured by enzyme-linked immunosorbent assays. The levels of CD4⁺ CD25⁺ Treg cells were determined by flow cytometric analysis. Patients with depression showed significantly higher serum levels of IL-6 and INF-γ, no altered serum levels of IL-10 and TNF-α, and decreased platelet and serum 5-HT levels compared with healthy participants at the first acquisition. In addition, the symptoms of depression and anxiety, the TNF-α level, and the amount of CD4⁺ CD25⁺ cells in the blood were decreased from the first to the second acquisition. Further, a correlation between IL-6 and platelet 5-HT has been observed in patients. An imbalance of the immune system in patients with depression and an association of the serotonergic system and cytokines were observed. These results indicate that the development of depression might be related to several interacting proteins, including cytokines and 5-HT, and the treatment affects imbalances of these factors.

Comparison of CD4+CD25hiFoxP3+ Treg Induction by pIL-10-Transfected Dendritic Cells in Different Mouse Strains

Tolerogenic dendritic cells (tolDCs) and T-regulatory cells (Tregs) are involved in maintaining tolerance to self-antigens and foreign antigens. The cells are used as therapeutic tools for inducing tolerance to transplanted organs or tissues. We investigated the possibility of inducing Tregs in splenocyte cultures using DCs transfected with a DNA construct encoding mouse interleukin-10 (DCpIL-10). DCs were derived from bone marrow cells in the presence of rmGM-CSF and rmIL-4 and electroporated with a plasmid encoding mouse IL-10. Furthermore, DCpIL-10 was cocultured with syngeneic splenocytes. The CD4⁺CD25^hiFoxP3⁺ Treg frequency, IL-10 expression, and inhibition of the mixed lymphocyte reaction were evaluated. C57Bl/6 and CBA mice differ in their initial frequency of CD4⁺CD25^hiFoxP3⁺ Tregs and baseline IL-10 production. Also, the effectiveness of CD4⁺CD25^hiFoxP3⁺ Treg upregulation by tolDCpIL-10 was different. In this study, DCpIL-10 from C57Bl/6 mice induced CD4⁺CD25^hiFoxP3⁺ Tregs in syngenic splenocytes, which was accompanied by an increase in the IL-10 production and a decrease in the proliferation of splenocytes in response to the alloantigen. DCpIL-10 may be used to induce CD4⁺CD25^hiFoxP3⁺ Tregs and the regulatory potential of splenocytes.

Severity of local inflammation does not impact development of fibrosis in mouse models of intestinal fibrosis

Intestinal fibrosis is thought to be a consequence of excessive tissue repair, and constitutes a common problem in patients with Crohn’s disease (CD). While fibrosis seems to require inflammation as a prerequisite it is unclear whether the severity or persistence of inflammation influences the degree of fibrosis. Our aim was to investigate the role of sustained inflammation in fibrogenesis. For the initiation of fibrosis in vivo the models of Il10^−/− spontaneous colitis, dextran sodium sulfate (DSS)-induced chronic colitis and heterotopic transplantation were used. In Il10^−/− mice, we determined a positive correlation between expression of pro-inflammatory factors (Il1β, Tnf, Ifnγ, Mcp1 and Il6). We also found a positive correlation between the expression of pro-fibrotic factors (Col3a1 Col1a1, Tgfβ and αSma). In contrast, no significant correlation was determined between the expression of pro-inflammatory Tnf and pro-fibrotic αSma, Col1a1, Col3a1, collagen layer thickness and the hydroxyproline (HYP) content. Results from the DSS-induced chronic colitis model confirmed this finding. In the transplantation model for intestinal fibrosis a pronounced increase in Mcp1, inos and Il6 in Il10^−/− as compared to WT grafts was observed, indicating more severe inflammation in Il10^−/− grafts. However, the increase of collagen over time was virtually identical in both Il10^−/− and WT grafts. Severity of inflammation during onset of fibrogenesis did not correlate with collagen deposition. Although inflammation might be a pre-requisite for the initiation of fibrosis our data suggest that it has a minor impact on the progression of fibrosis. Our results suggest that development of fibrosis and inflammation may be disconnected. This may be important for explaining the inefficacy of anti-inflammatory treatments agents in most cases of fibrotic inflammatory bowel diseases (IBD).

A Potential Role for Green Tea as a Radiation Sensitizer for Prostate Cancer

Prostate cancer (PCa) is the most common non-cutaneous cancer in the United States. There is currently a lack of safe and effective radiosensitizers that can enhance the effectiveness of radiation treatment (RT) for Pca. Clonogenic assay, PCNA staining, Quick Cell Proliferation assay, TUNEL staining and caspase-3 activity assay were used to assess proliferation and apoptosis in DU145 Pca cells. RT-PCR/IHC were used to investigate the mechanisms. We found that the percentage of colonies, PCNA staining intensity, and the optical density value of DU145 cells were decreased (RT/GT vs. RT). TUNEL + cells and the relative caspase-3 activity were increased (RT/GT vs. RT). Compared to RT, the anti-proliferative effect of RT/GT correlated with increased expression of the anti-proliferative molecule p16. Compared to RT, the pro-apoptotic effect of RT/GT correlated with decreased expression of the anti-apoptotic molecule Bcl-2. GT enhances RT sensitivity of DU145 by inhibiting proliferation and promoting apoptosis.

Resolution of inflammation: a new therapeutic frontier

Dysregulated inflammation is a central pathological process in diverse disease states. Traditionally, therapeutic approaches have sought to modulate the pro- or anti-inflammatory limbs of inflammation, with mixed success. However, insight into the pathways by which inflammation is resolved has highlighted novel opportunities to pharmacologically manipulate these processes - a strategy that might represent a complementary (and perhaps even superior) therapeutic approach. This Review discusses the state of the art in the biology of resolution of inflammation, highlighting the opportunities and challenges for translational research in this field.

IL-9 inhibits HTB-72 melanoma cell growth through upregulation of p21 and TRAIL

BACKGROUND

IL-9 is a pleiotropic cytokine produced mainly by Th9 cells. IL-9 may have an anti-proliferative role in murine melanoma, however, its effect on human melanoma is unknown.

METHODS

We examined the effects of IL-9 on proliferation and apoptosis in four human melanoma cell lines, HTB-65, HTB-72, CRL-11147, and SK-Mel-5. Clonogenic assay, PCNA staining, Quick Cell Proliferation assay, TUNEL staining and caspase-3 activity assay were used to assess proliferation and apoptosis, as appropriate.

RESULTS

We found that IL-9 decreased the percentage of colonies of HTB-72 and SK-Mel-5 cells but not that of HTB-65 or CRL-11147 cells. PCNA mRNA, PCNA+ cells, PCNA staining intensity, and the OD value of HTB-72 melanoma cells were consistently decreased in the present of IL-9. IL-9 also increased TUNEL+ cells and the relative caspase-3 activity in HTB-72 melanoma cells. We further investigated the possible molecular mechanisms using RT-PCR and immunohistochemical staining. The anti-proliferative effect of IL-9 on HTB-72 cells correlated with higher expression of anti-proliferative molecule p21. Its pro-apoptotic effect on HTB-72 cells correlated with higher expression of the pro-apoptotic molecule TRAIL.

CONCLUSIONS

IL-9 inhibits melanoma HTB-72 cell growth by upregulation of p21 and TRAIL. Understanding the interactions between IL-9 and melanoma may help direct strategies for cytokine-based immunotherapy development.

Association between Interlukin-6 (IL-6), Interlukin-10 (IL-10) and depression in patients undergoing Hematopoietic stem cell transplantation

BACKGROUND

The release of pro-inflammatory cytokines is responsible for the variety of behavioral, neuro-endocrine and neuro-chemical alterations in psychiatric condition. In this study we evaluate relation between depression and IL-6 and IL-10 in patients undergoing hematopoietic stem cell transplantation (HSCT).

MATERIALS AND METHODS

66 patients in this cross-sectional study from July 2013 until August 2014 for HSCT interred the study and were assessed for depression using Hospital Anxiety and Depression Scale (HADS). Serum interleukin (IL)-6, (IL)-10 and high sensitive C-reactive protein (hs-CRP) were assessed on the same time. Association between these biomarkers with depression was evaluated using SPSS version 20.

RESULTS

A total of 66 patients with the mean age of 41.18+13.92 and 41.95+12.35 years old in non depressed and depressed group respectively were enrolled in this study. Patients with depression showed significantly higher levels of serum IL-6 and the IL-6-to-IL-10 ratio compared to patients without depression (p<0.001).There was no statistically significant association between IL-10 and hs-CRP with depression in this group of the patients.

CONCLUSIONS

High IL-6 level has significant association with depression in patients undergoing HSCT. In conclusion, since IL-6 can affect the outcomes after HSCT and depression was associated with increased serum IL-6 level, early identification of depression can be beneficial in these patients.

IL-35 promotes pancreas cancer growth through enhancement of proliferation and inhibition of apoptosis: evidence for a role as an autocrine growth factor

Interleukin-35 (IL-35), an IL-12 cytokine family member, mediates the immune inhibitory function of regulatory T cells (Treg). We assayed the presence of IL-35 in paraffin-embedded human pancreas cancer (PCAN) and unexpectedly found IL-35 was expressed mainly by epithelial derived PCAN cells, but not by Treg. We further examined the expression and effect of exogenous IL-35 in human PCAN cell lines and found IL-35 promoted growth and inhibited apoptosis in PCAN cell lines. IL-35 induced proliferation correlated with an increase in cyclin B, cyclin D, cdk2, and cdk4 and a decrease in p27 expression, while inhibition of apoptosis was associated with an increase in Bcl-2 and a decrease in TRAILR1. We conclude IL-35 is produced by PCAN in vivo and promotes PCAN cell line growth in vitro. These results might indicate an important new role for IL-35 as an autocrine growth factor in PCAN growth.

Subacute thyroiditis in a patient with juvenile idiopathic arthritis undergoing etanercept treatment: a case report and review of the literature

We report on a 24-year-old woman with juvenile idiopathic arthritis (JIA) who developed subacute thyroiditis (SAT) while being treated with etanercept. She had suffered from JIA for 12 years, and her arthritis proved refractory to treatment with ibuprofen, prednisolone, and methotrexate. For the past 5 years, the patient had been treated successfully with etanercept at 25 mg/week. The patient more recently complained of high fever and lassitude, and presented with anterior neck swelling and tenderness. Palpation of the thyroid gland revealed it to be warm, erythematous, tender, and diffusely swollen. Laboratory tests revealed an increased erythrocyte sedimentation rate and C-reactive protein level. Thyroid function tests revealed decreased levels of thyrotropin-stimulating hormone, increased levels of free triiodothyronine, free thyroxine, and thyroglobulin, and an absence of thyroid autoantibodies. Sonography showed a diffusely reduced predominantly hypoechoic thyroid gland. Unenhanced computed tomography of the neck showed a homogeneously and mildly reduced thyroid gland. Serum titers of several viruses were not significant and so were considered unlikely to be the pathogens. On the basis of these presented findings, we diagnosed SAT, and etanercept therapy was withdrawn. The patient was treated with antibiotics and an increased prednisolone dose was initiated. She became symptom free and showed improved laboratory test results within 2 weeks, and was euthyroid by 3 months. Three months later, the patient developed hypothyroidism, although 6 months further on, the patient was asymptomatic on prednisolone, methotrexate, and levothyroxine therapy. In conclusion, whether SAT is a specific adverse event in this case in response to etanercept remains unclear. Nevertheless, the possibility of SAT should be considered in such patients on etanercept treatment.

TGF-β promotes proliferation of thyroid epithelial cells in IFN-γ(-/-) mice by down-regulation of p21 and p27 via AKT pathway

IFN-γ(-/-) NOD.H-2h4 mice develop an autoimmune disease characterized by hyperplasia and proliferation of thyroid epithelial cells (TEC H/P). Proliferating TECs produce TGF-β, and IFN-γ inhibits TEC H/P. In the present study, cultured TECs were used to directly determine the mechanisms by which these cytokines act on TECs to result in proliferation or inhibition of proliferation. With TECs from IFN-γ(-/-) NOD.H-2h4 mice or mice expressing the dominant negative TGF-β type II receptor on TECs, TGF-β was shown to promote TEC proliferation and IFN-γ was shown to inhibit TEC proliferation in vitro. TGF-β may promote TEC proliferation by down-regulating antiproliferative molecules p21 and p27, whereas IFN-γ may inhibit proliferation by up-regulating antiproliferative molecules p18 and p21 and down-regulating the pro-proliferative molecule cyclin D. Inhibition of AKT abolished the effect of TGF-β on p21 and p27, resulting in similar proliferation of TGF-β-treated and control TECs. Increased expression of proliferating cell nuclear antigen (PCNA), TGF-β, and p-AKT and decreased expression of p21 and p27 by proliferating TECs correlated with the proliferative state of TEC H/P. Taken together, the results suggest that TGF-β promotes TEC proliferation by down-regulating p21 and p27 via the AKT pathway in IFN-γ(-/-) NOD.H-2h4 mice, which may have significant implications for development of effective therapeutic strategies targeting the TGF-β and AKT pathways for treatment of hyperplasia and/or neoplasia.

Effect of transgenic overexpression of FLIP on lymphocytes on development and resolution of experimental autoimmune thyroiditis

In our previous studies, resolution of granulomatous experimental autoimmune thyroiditis (G-EAT) was promoted when thyroid epithelial cells were protected from Fas-mediated apoptosis due to transgenic overexpression of FLIP. We hypothesized that if FLIP were overexpressed on lymphocytes, CD4(+) effector cells would be protected from Fas-mediated apoptosis, and resolution would be delayed. To test this hypothesis, we generated transgenic (Tg) mice overexpressing FLIP under the CD2 promoter. Transgenic FLIP was expressed on CD4(+) and CD8(+) T cells and B cells. Transgenic overexpression of FLIP protected cultured splenocytes from Fas-mediated, but not irradiation-induced, apoptosis in vitro. Unexpectedly, Tg(+) donor cells transferred minimal G-EAT, which was partially overcome by depleting donor CD8(+) T cells. When Tg(+) and Tg(-) donors transferred equivalent disease, G-EAT resolution was delayed in FLIP transgenic mice. However, CD2-FLIP Tg(+) donors often transferred less severe G-EAT, even after depletion of CD8(+) T cells. This influenced the rate of G-EAT resolution, resulting in little difference in G-EAT resolution between groups. Tg(+) mice always had reduced anti-mouse thyroglobulin autoantibody responses, compared with Tg(-) littermates, presumably because of FLIP overexpression on B cells. These results suggest that effects of transgenic FLIP on a particular autoimmune disease vary, depending on what cells express the transgene and whether those cells are effector cells or if they function to modulate disease.

A case report of subacute thyroiditis during pregnancy: difficulties in differential diagnosis and changes in cytokine levels

INTRODUCTION

Thyroid dysfunction during pregnancy may result in both maternal and neonatal complications. Subacute thyroiditis (SAT) is an extremely rare cause of both hyper- and hypothyroidism in pregnant women.

CASE DESCRIPTION

A case of first trimester SAT is presented. Diagnosis of SAT was based on fine-needle aspiration biopsy. The disease resolved spontaneously without need for prednisone administration but a hypothyroid phase treated with T4 throughout pregnancy occurred. The pregnancy resulted in a healthy full term infant. We measured various cytokine levels in an attempt to follow their course during SAT as well as throughout the remaining period of pregnancy. Serum thyreoglobulin (Tg) levels correlated best with thyroid function tests (TFTs) and the course of SAT.

CONCLUSIONS

The diagnosis of SAT at a pregnancy setting may be intriguing. The measurement of circulating cytokines is not helpful in the differential diagnosis or monitoring of the disease.

Haplotype-dependent differential activation of the human IL-10 gene promoter in macrophages and trophoblasts: implications for placental IL-10 deficiency and pregnancy complications

PROBLEM

polymorphic changes in the IL-10 gene promoter have been identified that lead to altered IL-10 production. We hypothesized that because of these genotypic changes, the IL-10 promoter might be expressed in a cell type-specific manner and may respond differentially to inflammatory triggers.

METHOD OF STUDY

we created reporter gene promoter constructs containing GCC, ACC, and ATA haplotypes using DNA from patients harboring polymorphic changes at -1082 (G→A), -819 (C→T), and -592 (C→A) sites in the IL-10 promoter. These individual luciferase reporter constructs were transiently transfected into either primary term trophoblasts or THP1 monocytic cells. DNA-binding studies were performed to implicate the role of the Sp1 transcription factor in response to differential promoter activity.

RESULTS

our results suggest that the GCC promoter construct was activated in trophoblast cells in response to lipopolysaccharide (LPS), as demonstrated by reporter gene expression, but not in monocytic cells. The ACC construct showed weaker activation in both cell types. Importantly, while the ATA promoter was constitutively activated in both cell types, its expression was selectively repressed in response to LPS, but only in trophoblasts. DNA-nuclear protein binding assays with nuclear extracts from LPS treated or untreated cells suggested a functional relevance for Sp1 binding differences at the -592 position.

CONCLUSIONS

these results demonstrate cell type-specific effects of the genotypic changes in the IL-10 gene promoter. These responses may be further modulated by bacterial infections or other inflammatory conditions to suppress IL-10 production in human trophoblasts.

Comparison of sensitivity of Th1, Th2, and Th17 cells to Fas-mediated apoptosis

Following activation through the TCR, CD4+ T cells can differentiate into three major subsets: Th1, Th2, and Th17 cells. IL-17-secreting Th17 cells play an important role in the pathogenesis of several autoimmune diseases and in immune responses to pathogens, but little is known about the regulation of apoptosis in Th17 cells. In this study, the sensitivity of in vitro-polarized Th1, Th2, and Th17 cells to Fas-mediated apoptosis was compared directly by different methods. The order of sensitivity of T cell subsets to Fas-mediated apoptosis is: Th1 > Th17 > Th2. The greater sensitivity of Th17 cells to Fas-mediated apoptosis compared with Th2 cells correlated with their higher expression of FasL and comparable expression of the antiapoptotic molecule FLIP. The decreased sensitivity of Th17 compared with Th1 cells correlated with the higher expression of FLIP by Th17 cells. Transgenic overexpression of FLIP in T cells protected all three subsets from Fas-mediated apoptosis. These findings provide new knowledge for understanding how survival of different subsets of T cells is regulated.

Eosinophils infiltrate thyroids, but have no apparent role in induction or resolution of experimental autoimmune thyroiditis in interferon-gamma(-/-) mice

Granulomatous experimental autoimmune thyroiditis (G-EAT) is induced by mouse thyroglobulin (MTg)-sensitized splenocytes activated with MTg and interleukin (IL)-12. Our previous studies showed that, when used as donors and recipients, interferon (IFN)-gamma(-/-) and wild-type (WT) DBA/1 mice both develop severe G-EAT. Thyroid lesions in IFN-gamma(-/-) mice have many eosinophils and few neutrophils, while those in WT mice have extensive neutrophil infiltration and few eosinophils. Thyroid lesions in IFN-gamma(-/-) mice consistently resolve by day 40-50, whereas those in WT mice have ongoing inflammation and fibrosis persisting for more than 60 days. To determine if the extensive infiltration of eosinophils in thyroids of IFN-gamma(-/-) mice contributes to thyroid damage and/or early resolution of G-EAT, anti-IL-5 was used to inhibit migration of eosinophils to thyroids. G-EAT severity was compared at day 20 and day 40-50 in IFN-gamma(-/-) recipients given anti-IL-5 or control immunoglobulin G (IgG). Thyroids of anti-IL-5-treated IFN-gamma(-/-) mice had few eosinophils and more neutrophils at day 20, but G-EAT severity scores were comparable to those of control IgG-treated mice at both day 20 and day 40-50. Expression of chemokine (C-X-C motif) ligand 1 (CXCL1) mRNA was higher and that of chemokine (C-C motif) ligand 11 (CCL11) mRNA was lower in thyroids of anti-IL-5-treated IFN-gamma(-/-) mice. IL-5 neutralization did not influence mRNA expression of most cytokines in IFN-gamma(-/-) mice. Thus, inhibiting eosinophil migration to thyroids did not affect G-EAT severity or resolution in IFN-gamma(-/-) mice, suggesting that eosinophil infiltration of thyroids occurs as a consequence of IFN-gamma deficiency, but these cells have no apparent pathogenic role in G-EAT.

Low serum IL-10 concentrations and loss of regulatory association between IL-6 and IL-10 in adults with major depression

Elevated circulating pro-inflammatory cytokines are associated with symptoms of depression, and disorders involving chronic inflammation are often co-morbid with major depression. Since healthy immune regulation is accomplished through counter-balancing effects of pro- and anti-inflammatory cytokines, we hypothesized that depressed subjects (compared to controls) would express lower concentrations of the anti-inflammatory/immunoregulatory cytokine interleukin (IL)-10, and a higher IL-6/IL-10 ratio. We also examined the possibility that depressed subjects may exhibit a deficiency in the regulatory loop involving IL-6 induced secretion of IL-10. Therefore, we hypothesized that circulating IL-6 and IL-10 would be positively correlated in controls, while the correlation would be weaker in depressed subjects. Resting state serum cytokine concentrations were quantified in 12 unmedicated depressed subjects, and 11 age, gender, and ethnicity-matched controls. Depressed subjects showed significantly lower IL-10 (p=0.03, Cohen's d=-0.96), non-significantly higher IL-6, and significantly higher IL-6/IL-10 ratios (p=0.05, Cohen's d=0.50). Across all participants, higher scores on the self-rated Inventory of Depressive Symptoms were associated with lower IL-10 (r(21)=-0.57, p=0.005) and non-significantly higher IL-6/IL-10 ratios (r(21)=0.38, p=0.07), but not related to IL-6 concentrations. As hypothesized, IL-6 and IL-10 concentrations were strongly and positively correlated in controls (r(9)=0.81, p=0.003), but were completely dissociated in depressed subjects (r(10)=0.01, p=0.98). These results suggest that lower IL-10 levels, a higher IL-6/IL-10 ratio, and the apparent absence of a counter-balancing, immunoregulatory increase in IL-10 in response to elevated IL-6 concentrations contribute to the pro-inflammatory physiological milieu that is known to be associated with major depression. Therefore, reduced induction/availability of IL-10, that would normally inhibit pro-inflammatory cytokine actions and resolve inflammation, may contribute to the depressogenic as well as the inflammatory disease-promoting effects of chronic, low-level elevations in pro-inflammatory cytokines.

Cytoprotective effects of human interleukin-10 gene transfer against necrosis and apoptosis induced by hepatic cold ischemia/reperfusion injury

BACKGROUND

Apoptosis as well as necrosis may play an important role in hepatic ischemia/reperfusion (I/R) injury. Interleukin 10 (IL-10), a Th2 type cytokine, modulates inflammatory responses by inhibiting the production of proinflammatory cytokines. The study focused on cytoprotective and antiapoptotic pathways to assess mechanisms by which gene transduction of human IL-10 (hIL-10) may renders grafts resistant to the cold I/R injury.

MATERIALS AND METHODS

Adenoviruses encoding hIL-10 or beta-galactosidase (LacZ) were injected via the superior mesenteric vein into prospective donor animals. The donor liver was harvested 48h after transduction, and stored for 12h at 4 degrees C lactated Ringer's solution prior to being transplanted. Graft survival, liver function, the degree of necrosis and apoptosis, and the molecules of apoptotic networks were assessed.

RESULTS

Ad-hIL-10 pretreatment significantly prolonged the survival of liver grafts by improving liver function, preserving hepatocyte integrity and architecture, and depressing intrahepatic apoptosis and necrosis. In addition, Ad-hIL-10 pretreatment diminished the release of cytochrome c from mitochondria into cytoplasm and caspase-3 activity, with simultaneous up-regulated of antioxidant HO-1 and anti-antiapoptotic Bcl-2 molecules.

CONCLUSION

Adenoviral gene transfer of hIL-10 ameliorated cold I/R injury by decreasing hepatic necrosis and apoptosis. The underlying mechanism of cytoprotective effects may at least be involved with the inhibition of caspase-3 activity and mitochondrial cytochrome c release, and the up-regulation of antiapoptotic (Bcl-2) and antioxidant (HO-1) molecules.

Regenerative potentials of the murine thyroid in experimental autoimmune thyroiditis: role of CD24

Hashimoto thyroiditis can be partially reproduced in mice by immunization with thyroglobulin or, more recently, thyroperoxidase. This experimental autoimmune thyroiditis (EAT) model has been extensively characterized during early disease phases (up to d 35 after immunization). By extending the analysis of EAT to 100 d after immunization, we noted a remarkable regenerative capacity of the thyroid and the expression of Oct-4, suggesting in vivo the existence of adult thyroid stem cells. After an almost complete destruction of the follicular architecture, occurring between d 21 and 28, the thyroid was capable of restoring its follicles and reducing the mononuclear infiltration, so that by d 100 after immunization, it regained its normal morphology and function. During this regeneration process, thyrocytes expressed high levels of CD24. We therefore assessed the role of CD24 in thyroid regeneration by inducing EAT in mice lacking CD24. Regeneration was faster in the absence of CD24, likely a consequence of the effect of CD24 on the infiltrating lymphocytes. The study suggests that the EAT model can also be used as a tool to investigate adult thyroid stem cells.

A critical role for TRAIL in resolution of granulomatous experimental autoimmune thyroiditis

Granulomatous experimental autoimmune thyroiditis (G-EAT) is induced by mouse thyroglobulin (MTG)-sensitized splenocytes activated in vitro with MTG and IL-12. Thyroid lesions reach maximal severity 20 days after cell transfer, and usually resolve or progress to fibrosis by day 60 depending on the extent of thyroid damage at day 20. Our previous studies indicated that neutralization of TNF-alpha or FasL had no effect on G-EAT induction, but neutralization of TNF-alpha promoted, while neutralization of FasL inhibited, G-EAT resolution. TNF-related apoptosis-inducing ligand (TRAIL) is a member of the TNF superfamily. This study was undertaken to define the role of endogenous TRAIL in G-EAT development and/or resolution. Neutralization of endogenous TRAIL had little effect on G-EAT induction, but significantly inhibited G-EAT resolution and increased thyroid fibrosis. This correlated with higher expression of pro-inflammatory cytokines and preferential expression of the pro-apoptotic molecule TRAIL, and anti-apoptotic molecules FLIP and Bcl-xL on inflammatory cells in thyroids of anti-TRAIL-treated recipients. The results suggest that endogenous TRAIL is not required for G-EAT development in recipients, but is critical for G-EAT resolution. Endogenous TRAIL might promote resolution, at least in part, through modulation of the balance between pro- and anti-inflammatory cytokines, and the expression pattern of pro- and anti-apoptotic molecules of thyroid epithelial cells (TECs) and inflammatory cells.