Role of chemokines in endocrine autoimmune diseases.

Chemokines are a group of peptides of low molecular weight that induce the chemotaxis of different leukocyte subtypes. The major function of chemokines is the recruitment of leukocytes to inflammation sites, but they also play a role in tumoral growth, angiogenesis, and organ sclerosis. In the last few years, experimental evidence accumulated supporting the concept that interferon-gamma (IFN-gamma) inducible chemokines (CXCL9, CXCL10, and CXCL11) and their receptor, CXCR3, play an important role in the initial stage of autoimmune disorders involving endocrine glands. The fact that, after IFN-gamma stimulation, endocrine epithelial cells secrete CXCL10, which in turn recruits type 1 T helper lymphocytes expressing CXCR3 and secreting IFN-gamma, thus perpetuating autoimmune inflammation, strongly supports the concept that chemokines play an important role in endocrine autoimmunity. This article reviews the recent literature including basic science, animal models, and clinical studies, regarding the role of these chemokines in autoimmune endocrine diseases. The potential clinical applications of assaying the serum levels of CXCL10 and the value of such measurements are reviewed. Clinical studies addressing the issue of a role for serum CXCL10 measurement in Graves' disease, Graves' ophthalmopathy, chronic autoimmune thyroiditis, type 1 diabetes mellitus, and Addison's disease have been considered. The principal aim was to propose that chemokines, and in particular CXCL10, should no longer be considered as belonging exclusively to basic science, but rather should be used for providing new insights in the clinical management of patients with endocrine autoimmune diseases.

An alternatively spliced variant of CXCR3 mediates the inhibition of endothelial cell growth induced by IP-10, Mig, and I-TAC, and acts as functional receptor for platelet factor 4.

The chemokines CXCL9/Mig, CXCL10/IP-10, and CXCL11/I-TAC regulate lymphocyte chemotaxis, mediate vascular pericyte proliferation, and act as angiostatic agents, thus inhibiting tumor growth. These multiple activities are apparently mediated by a unique G protein-coupled receptor, termed CXCR3. The chemokine CXCL4/PF4 shares several activities with CXCL9, CXCL10, and CXCL11, including a powerful angiostatic effect, but its specific receptor is still unknown. Here, we describe a distinct, previously unrecognized receptor named CXCR3-B, derived from an alternative splicing of the CXCR3 gene that mediates the angiostatic activity of CXCR3 ligands and also acts as functional receptor for CXCL4. Human microvascular endothelial cell line-1 (HMEC-1), transfected with either the known CXCR3 (renamed CXCR3-A) or CXCR3-B, bound CXCL9, CXCL10, and CXCL11, whereas CXCL4 showed high affinity only for CXCR3-B. Overexpression of CXCR3-A induced an increase of survival, whereas overexpression of CXCR3-B dramatically reduced DNA synthesis and up-regulated apoptotic HMEC-1 death through activation of distinct signal transduction pathways. Remarkably, primary cultures of human microvascular endothelial cells, whose growth is inhibited by CXCL9, CXCL10, CXCL11, and CXCL4, expressed CXCR3-B, but not CXCR3-A. Finally, monoclonal antibodies raised to selectively recognize CXCR3-B reacted with endothelial cells from neoplastic tissues, providing evidence that CXCR3-B is also expressed in vivo and may account for the angiostatic effects of CXC chemokines.

New insights on the neuroprotective role of sterols and sex steroids: the seladin-1/DHCR24 paradigm.

In 2000 a new gene, i.e. seladin-1 (for selective Alzheimer's disease indicator-1) was identified and found to be down regulated in vulnerable brain regions in Alzheimer's disease. Seladin-1 was considered a novel neuroprotective factor, because of its anti-apoptotic properties. Subsequently, it has been demonstrated that seladin-1 corresponds to the gene that encodes 3-beta-hydroxysterol delta-24-reductase (DHCR24), that catalyzes the synthesis of cholesterol from desmosterol. There is evidence that cholesterol plays a fundamental role in maintaining brain homeostasis. Because of its enzymatic activity, seladin-1/DHCR24 has been considered the human homolog of the plant protein DIMINUTO/DWARF1, that is involved in the synthesis of sterol plant hormones. We have recently demonstrated that seladin-1/DHCR24 is a fundamental mediator of the protective effects of estrogens in the brain. This review describes how this protein interacts with cholesterol and estrogens, thus generating a neuroprotective network, that might open new possibilities in the prevention/treatment of neurodegenerative diseases.

Interferon-alpha, -beta and -gamma induce CXCL9 and CXCL10 secretion by human thyrocytes: modulation by peroxisome proliferator-activated receptor-gamma agonists.

It has been hypothesized that interferon (IFN) alpha and beta cause autoimmune thyroid dysfunctions by changing the Th1/Th2 balance, but the mechanisms involved are not yet known. The aims of this study were: (a) to test the effect of IFNalpha, IFNbeta and IFNgamma on the secretion of the Th1 chemokines CXCL9 and CXCL10, in "primary cultures of human thyroid follicular cells" (TFC); (b) to assess the effect of PPARgamma activation on CXCL9 and CXCL10 secretion. In TFC, CXCL9 and CXCL10 were undetectable in the supernatant. IFNgamma, IFNalpha and IFNbeta, dose dependently induced CXCL9 and CXCL10 release. TNFalpha alone had no effect. The combination of each of the IFNs with TNFalpha had a significant synergistic effect on CXCL9 and CXCL10 secretion. Treatment of TFC with rosiglitazone dose dependently inhibited the IFNs-stimulated CXCL9 and CXCL10 release. Compared with IFNalpha and IFNbeta, IFNgamma was the most potent stimulus of CXCL9 and CXCL10 secretion. In conclusion, IFNalpha, IFNbeta, IFNgamma and TNFalpha (synergistically with IFNs) dose-dependently induce the release of CXCL9 and CXCL10 by TFC, suggesting that this process may be related, at least in part, to the appearance of thyroid dysfunction during IFNs therapy. Furthermore, PPARgamma activation partially inhibits this process.

Characterization of human adult stem-cell populations isolated from visceral and subcutaneous adipose tissue.

Adipose tissue is a dynamic endocrine organ with a central role in metabolism regulation. Functional differences in adipose tissue seem associated with the regional distribution of fat depots, in particular in subcutaneous and visceral omental pads. Here, we report for the first time the isolation of human adipose-derived adult stem cells from visceral omental and subcutaneous fat (V-ASCs and S-ASCs, respectively) from the same subject. Immunophenotyping shows that plastic culturing selects homogeneous cell populations of V-ASCs and S-ASCs from the corresponding stromal vascular fractions (SVFs), sharing typical markers of mesenchymal stem cells. Electron microscopy and electrophysiological and real-time RT-PCR analyses confirm the mesenchymal stem nature of both V-ASCs and S-ASCs, while no significant differences in a limited pattern of cytokine/chemokine expression can be detected. Similar to S-ASCs, V-ASCs can differentiate in vitro toward adipogenic, osteogenic, chondrogenic, muscular, and neuronal lineages, as demonstrated by histochemical, immunofluorescence, real-time RT-PCR, and electrophysiological analyses, suggesting the multipotency of such adult stem cells. Our data demonstrate that both visceral and subcutaneous adipose tissues are a source of pluripotent stem cells with multigermline potential. However, the visceral rather than the subcutaneous ASC could represent a more appropriate in vitro cell model for investigating the molecular mechanisms implicated in the pathophysiology of metabolic disorders such as obesity.

Seladin-1 and testicular germ cell tumours: new insights into cisplatin responsiveness.

The molecular basis for the exquisite sensitivity of testicular germ cell tumours of adolescents and adults (TGCTs), ie seminomas and non-seminomatous germ cell tumours, to chemo/radiotherapy has not been fully clarified so far. It has been suggested that it may be dependent on factors involved in the regulation of apoptosis. Seladin-1 is a multi-functional protein involved in various biological processes, including apoptosis. The aim of our study was to assess the expression of seladin-1 in different histological types of TGCTs, known to have varying treatment sensitivity, in order to establish whether this protein may influence cisplatin responsiveness in vitro. Seladin-1 expression levels, both at the mRNA and at the protein level, were higher in the adjacent normal parenchyma than in the pathological counterparts. In tumoural tissues, the level of expression differed among TGCT histological types. The highest tumour-expression level was found in teratoma, whereas the lowest was detected in seminoma, corresponding to the different chemo/and radiosensitivities of these tumour types. In common with other cancers, in TGCT-derived cell lines seladin-1 showed anti-apoptotic properties through inhibition of caspase-3 activation. We confirmed our results using a non-seminomatous cell line model (NT2) before and after differentiation with retinoic acid. Significantly higher seladin-1 expression was observed in the differentiated derivatives (teratoma) and an inverse relationship was found between seladin-1 expression and the amount of cleaved caspase-3. Seladin-1 silencing or overexpression in this cell line supports involvement of seladin-1 in cisplatin responsiveness. Seladin-1 silencing was associated with greater cisplatin responsiveness demonstrated by decreased cell viability and increased expression of apoptotic markers. In contrast, overexpression of seladin-1 was associated with a higher survival rate and a clear anti-apoptotic effect. In conclusion, we have demonstrated for the first time an important role for seladin-1 in the biology of TGCTs and provided new insights into cisplatin responsiveness of these tumours.

Comparison between VDR analogs and current immunosuppressive drugs in relation to CXCL10 secretion by human renal tubular cells.

During kidney allograft rejection, CXC chemokine ligand 10 (CXCL10)-CXC chemokine receptor 3 (CXCR3) trafficking between peripheral blood and tissues initiates alloresponse and perpetuates a self-inflammatory loop; thus, CXCL10-CXCR3 axis could represent a pharmacologic target. In this perspective, immunosuppressors targeting graft-resident cells, beside immune cells, could be very advantageous. Vitamin D receptor (VDR) agonists exhibit considerable immunomodulatory properties. This study aimed to investigate whether elocalcitol and BXL-01-0029 could decrease the expression of CXCL10 in activated renal tubular cells in vitro and thus be useful in kidney allograft rejection treatment. Experiments were performed in human tubular renal cells stimulated with interferon-gamma + tumor necrosis factor-alpha with and without VDR agonists, tacrolimus, sirolimus, hydrocortisone, methylprednisolone, cyclosporin A and mycophenolate mofetil. CXCL10 protein secretion and gene expression were measured by ELISA and by quantitative PCR. Specific inhibitors were used to investigate intracellular pathways involved in tubular cells activation. For IC(50) determination and comparison, dose-response curves with VDR agonists, tacrolimus and mycophenolic acid were performed. Elocalcitol and BXL-01-0029 inhibited CXCL10 secretion by renal cells, without affecting cell viability, while almost all the immunosuppressors were found to be ineffective, except for tacrolimus and mycophenolate mofetil. BXL-01-0029 was the most potent drug and, notably, it was found to be capable of allowing reduction in tacrolimus-inhibitory doses. Our data suggest that BXL-01-0029 could potentially be a dose-reducing agent for conventional immunosuppressors in kidney rejection management.

High pretransplant serum levels of CXCL9 are associated with increased risk of acute rejection and graft failure in kidney graft recipients.

Several clinical and experimental models have underlined the role of the CXCR3-binding chemokines in the immune-mediated kidney diseases. This study aimed to investigate the predictive value of measuring pretransplant CXCL9 levels for acute rejection (AR) onset and kidney transplantation outcome. Pretransplantation serum levels of CXCL9 were tested retrospectively in 252 kidney graft recipients, whose stratification in two groups according to CXCL9 levels (<272.1 pg/ml vs. >272.1 pg/ml) showed highly significant differences in 5-year survival rates (97.7% vs. 73.3%; P < 0.001). Multivariate analysis demonstrated that among the analysed variables, CXCL9 [relative risk (RR) 11.708] and AR (RR 3.604) had the highest predictive power of graft loss. Accordingly, patients with AR (254.4 + or - 22.1; P < 0.05) and, even more, those with anti-thymoglobulin (ATG)-treated AR also showed increased pretransplant serum CXCL9 levels (319.3 + or - 28.1, P < 0.001). Moreover, CXCL9 expression and distribution were investigated in tissue specimens obtained from 10 patients affected by AR, and wide CXCL9 expression was detected not only in infiltrating inflammatory cells but also in vascular and tubular structures. Measurement of pretransplant serum CXCL9 levels might represent the tracking of a clinically useful parameter to identify subjects at high risk of AR and graft failure. These findings might be used for the individualization of immunosuppressive therapies.

Regeneration of glomerular podocytes by human renal progenitors.

Depletion of podocytes, common to glomerular diseases in general, plays a role in the pathogenesis of glomerulosclerosis. Whether podocyte injury in adulthood can be repaired has not been established. Here, we demonstrate that in the adult human kidney, CD133+CD24+ cells consist of a hierarchical population of progenitors that are arranged in a precise sequence within Bowman's capsule and exhibit heterogeneous potential for differentiation and regeneration. Cells localized to the urinary pole that expressed CD133 and CD24, but not podocyte markers (CD133+CD24+PDX- cells), could regenerate both tubular cells and podocytes. In contrast, cells localized between the urinary pole and vascular pole that expressed both progenitor and podocytes markers (CD133+CD24+PDX+) could regenerate only podocytes. Finally, cells localized to the vascular pole did not exhibit progenitor markers, but displayed phenotypic features of differentiated podocytes (CD133-CD24-PDX+ cells). Injection of CD133+CD24+PDX- cells, but not CD133+CD24+PDX+ or CD133-CD24- cells, into mice with adriamycin-induced nephropathy reduced proteinuria and improved chronic glomerular damage, suggesting that CD133+CD24+PDX- cells could potentially treat glomerular disorders characterized by podocyte injury, proteinuria, and progressive glomerulosclerosis.

A new mechanism involving ERK contributes to rosiglitazone inhibition of tumor necrosis factor-alpha and interferon-gamma inflammatory effects in human endothelial cells.

OBJECTIVE: Microvascular endothelium is one of the main targets of the inflammatory response. On specific activation, endothelial cells recruit Th1-lymphocytes at the inflammatory site. We investigated the intracellular signaling mediating tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma inflammatory response in human microvascular endothelial cells (HMEC-1) and the interfering effects of the peroxisome-proliferator-activated-receptor (PPARgamma) agonist, rosiglitazone (RGZ). METHODS AND RESULTS: TNFalpha and IFNgamma, mainly when combined, stimulate IFNgamma-inducible protein of 10 kDa (IP10) and fractalkine production evaluated by ELISA and TaqMan analyses. This effect is not only mediated by activation of the NFkB and Stat1 classic pathways, but also involves a rapid increase in phosphorylation and activation of extracellular signal-regulated kinases (ERK1/2) as measured by Western blot. RGZ interferes with TNFalpha and IFNgamma stimulation of IP10, fractalkine, and adhesion molecule through a novel rapid mechanism which involves the blocking of ERK activation. CONCLUSIONS: Our findings shed new light on the mechanisms underlying the inflammatory response of microvascular endothelium and on the possible therapeutic use of RGZ in vasculopathies involving Th1-responses.

Pretransplant positivity for circulating thyroid antibodies and graft survival in patients undergoing kidney transplant.

BACKGROUND: Thyroid disturbances are common in kidney graft recipients and they may influence graft function. CXC chemokine ligand 10 plays a role in both autoimmune thyroiditis and graft rejection. Thyroid antibody (Ab) positivity has been regarded as a marker of imbalance of the immune system. AIM: To relate pretransplant positivity for antithyroperoxidase (TPO) Ab and antithyroglobulin (Tg) Ab with kidney graft outcome. METHODS: Pretransplant thyroid antibodies were measured in 211 kidney graft recipients. RESULTS: The 5-year death-censored graft survival rate was 91.5%. Pretransplant circulating Tg Ab and TPO Ab were detected in 12 (5.7%) and 13 (6.2%) patients, respectively. Lifetime analysis showed similar 5-year graft survival rates in patients negative or positive for Tg Ab and TPO Ab (91.5 vs. 91.7% for Tg Ab and 91.9 vs. 84.6% for TPO Ab). However, patients with pretransplant positivity for TPO Ab showed a significantly lower 5-year graft survival when early graft loss (12 months after transplant) was excluded (84.6 and 96.8% for TPO Ab+ and TPO Ab- patients, respectively; p < 0.05). Occurrence of acute rejection and chronic allograft nephropathy was unrelated to thyroid Ab positivity. Serum CXC chemokine ligand 10 levels were similar independent of Tg Ab and TPO Ab positivity. CONCLUSION: Pretransplant positivity for TPO Ab may affect long-term graft survival in kidney graft recipients independent of occurrence of acute rejections and chronic allograft nephropathy.

Seladin-1 is a fundamental mediator of the neuroprotective effects of estrogen in human neuroblast long-term cell cultures.

Estrogen exerts neuroprotective effects and reduces beta-amyloid accumulation in models of Alzheimer's disease (AD). A few years ago, a new neuroprotective gene, i.e. seladin-1 (for selective AD indicator-1), was identified and found to be down-regulated in AD vulnerable brain regions. Seladin-1 inhibits the activation of caspase-3, a key modulator of apoptosis. In addition, it has been demonstrated that the seladin-1 gene encodes 3beta-hydroxysterol Delta24-reductase, which catalyzes the synthesis of cholesterol from desmosterol. We have demonstrated previously that in fetal neuroepithelial cells, 17beta-estradiol (17betaE2), raloxifene, and tamoxifen exert neuroprotective effects and increase the expression of seladin-1. The aim of the present study was to elucidate whether seladin-1 is directly involved in estrogen-mediated neuroprotection. Using the small interfering RNA methodology, significantly reduced levels of seladin-1 mRNA and protein were obtained in fetal neuroepithelial cells. Seladin-1 silencing determined the loss of the protective effect of 17betaE2 against beta-amyloid and oxidative stress toxicity and caspase-3 activation. A computer-assisted analysis revealed the presence of half-palindromic estrogen responsive elements upstream from the coding region of the seladin-1 gene. A 1490-bp region was cloned in a luciferase reporter vector, which was transiently cotransfected with the estrogen receptor alpha in Chinese hamster ovarian cells. The exposure to 17betaE2, raloxifene, tamoxifen, and the soy isoflavones genistein and zearalenone increased luciferase activity, thus suggesting a functional role for the half-estrogen responsive elements of the seladin-1 gene. Our data provide for the first time a direct demonstration that seladin-1 may be considered a fundamental mediator of the neuroprotective effects of estrogen.

Androgen receptor regulation of the seladin-1/DHCR24 gene: altered expression in prostate cancer.

Prostate cancer (CaP) represents a major leading cause of morbidity and mortality in the Western world. Elevated cholesterol levels, resulting from altered cholesterol metabolism, have been found in CaP cells. Seladin-1 (SELective Alzheimer Disease INdicator-1)/DHCR24 is a recently described gene involved in cholesterol biosynthesis. Here, we demonstrated the androgen regulation of seladin-1/DHCR24 expression, due to the presence of androgen responsive element sequences in its promoter region. In metastatic androgen receptor-negative CaP cells seladin-1/DHCR24 expression and cholesterol amount were reduced compared to androgen receptor-positive cells. In tumor samples from 61 patients who underwent radical prostatectomy the expression of seladin-1/DHCR24 was significantly higher with respect to normal tissues. In addition, in cancer tissues mRNA levels were positively related to T stage. In tumor specimens from 23 patients who received androgen ablation treatment for 3 months before surgery seladin-1/DHCR24 expression was significantly lower with respect to patients treated by surgery only. In conclusion, our study demonstrated for the first time the androgen regulation of the seladin-1/DHCR24 gene and the presence of a higher level of expression in CaP tissues, compared to the normal prostate. These findings, together with the results previously obtained in metastatic disease, suggest an involvement of this gene in CaP.

Pretransplant serum FT3 levels in kidney graft recipients are useful for identifying patients with higher risk for graft failure.

OBJECTIVE: End-stage renal disease (ESRD) is a condition associated with thyroid disturbances both in function and morphology. Recent studies demonstrated that serum free triiodothyronine 3 (FT3) levels are negatively correlated with serum markers of inflammation and endothelial activation in patients with ESRD. However, no previous research evaluated serum thyroid function parameters in relation to kidney graft outcome, as we aim to do so in this study. DESIGN: Serum FT3, free thyroxine 4 (FT4) and TSH levels were measured before transplantation in 196 kidney graft recipients. RESULTS: The graft survival rate at 5 years for all patients was 92.3%. Kidney graft recipients with normally functioning grafts showed serum pretransplant thyroid parameters similar to patients who experienced graft failure. Life-time analysis was performed after stratification of patients according to pretransplant serum FT3 levels < 3.1 pmol/l or > 3.1 pmol/l. A significantly different 5-year death-censored graft survival rate (93.9%vs. 76.5% for patients with normal or low FT3 levels, respectively; P < 0.01) and similar survival rate (death of patients with functioning grafts) (21.1%vs. 5.9%; P = 0.288) were observed. No similar feature was found for FT4 or TSH, suggesting that the effect is not related to hypothyroidism but rather dependent upon inappropriately low FT3 levels. Pretransplant serum FT3 levels were similar in patients who experienced early acute rejections as compared with nonrejector patients. CONCLUSIONS: The results of this study demonstrate that among patients with ESRD undergoing kidney transplantation, those displaying lower pretransplant serum FT3 levels are at higher risk for subsequent graft failure. The demonstration of a predictive value of serum FT3 levels for graft survival suggests that measurement of pretransplant serum FT3 levels might represent a clinically useful parameter to identify patients with increased risk for graft failure.

Correlation between, clinical, biochemical, color Doppler ultrasound thyroid parameters, and CXCL-10 in autoimmune thyroid diseases.

OBJECTIVE: the aim of present study is to determine possible contributions of INF-gamma inducible chemochine CXCL-10 in the thyroid color doppler ultrasound (CDU) parameters typical of autoimmune disorders. METHODS: we studied a consecutive series of 25 patients with autoimmune thyroid disease and 10 healthy control subjects. All subjects underwent a thyroid CDU examination by the same investigator, who was unaware of the laboratory values at the time of the examination. Moreover, all subjects underwent a clinical evaluation, CXCL-10 and thyroid hormonal assessment. RESULTS: CXCL-10 levels were significantly higher in patients with autoimmune diseases and as well as in subjects with an increased thyroid vascularization at CDU. Moreover, CXCL-10 levels were significantly (p<0.05) correlated with inferior thyroid arteria peak systolic velocity (ITA-PSV; r = 0.376) and with thyroid volume even after adjustment for confounding factors. No difference was observed between vascular thyroid pattern at CDU and thyroid circulating hormones while, ITA-PSV was significantly associated with TSH (Adj. r = -0.373; p<0.05). CONCLUSIONS: our data seem to suggest that CXCL-10 could play an important role in the intra-thyroid angiogenesis modulation, explaining, at least partiality, CDU findings typical of thyroid autoimmune diseases. Moreover we confirmed previous reports considering ITA-PSV as the best CDU parameters in the differential diagnosis of thyroid autoimmune disorders.

Regenerative potential of embryonic renal multipotent progenitors in acute renal failure.

Bone marrow-and adult kidney-derived stem/progenitor cells hold promise in the development of therapies for renal failure. Here is reported the identification and characterization of renal multipotent progenitors in human embryonic kidneys that share CD24 and CD133 surface expression with adult renal progenitors and have the capacity for self-renewal and multilineage differentiation. It was found that these CD24+CD133+ cells constitute the early primordial nephron but progressively disappear during nephron development until they become selectively localized to the urinary pole of Bowman's capsule. When isolated and injected into SCID mice with acute renal failure from glycerol-induced rhabdomyolysis, these cells regenerated different portions of the nephron, reduced tissue necrosis and fibrosis, and significantly improved renal function. No tumorigenic potential was observed. It is concluded that CD24+CD133+ cells represent a subset of multipotent embryonic progenitors that persist in human kidneys from early stages of nephrogenesis. The ability of these cells to repair renal damage, together with their apparent lack of tumorigenicity, suggests their potential in the treatment of renal failure.

Iodine-131 given for therapeutic purposes modulates differently interferon-gamma-inducible alpha-chemokine CXCL10 serum levels in patients with active Graves' disease or toxic nodular goiter.

CONTEXT: The mechanism of activation of the immune system after iodine-131 (131I) treatment of hyperthyroidism is still not fully clarified. Serum levels of CXCL10, a prototype of the CXC family of chemokines, are increased in several endocrine autoimmune conditions, and this chemokine plays a role at least in the initial phases of thyroid autoimmune disease and in Graves' disease (GD). OBJECTIVE, DESIGN, AND PATIENTS: The aim of the present study was to measure the serum CXCL10 levels in 20 patients with GD and 10 patients with toxic nodular goiter (TNG) before and 6 months after 131I treatment, when patients had achieved euthyroidism. Forty healthy subjects and 40 patients with autoimmune thyroiditis served as control groups. RESULTS: Before 131I, mean CXCL10 was significantly higher in patients with GD and thyroiditis than controls or those with TNG. Serum CXCL10 levels significantly decreased in GD patients 6 months after 131I treatment, whereas they remained within normal limits in TNG patients after restoration of euthyroidism by 131I. CONCLUSIONS: In conclusion, our results demonstrate that high serum CXCL10 levels are associated with the hyperthyroid phase in GD but not TNG, providing further evidence for a minimal role of hyperthyroidism per se in determining high CXCL10 levels and showing a strong association with the autoimmune process. The reduction of CXCL10 levels after 131I treatment in GD only shows that the thyroid gland itself is the main source of circulating CXCL10.

Serum CXCL10 levels and occurrence of thyroid dysfunction in patients treated with interferon-alpha therapy for hepatitis C virus-related hepatitis.

OBJECTIVE: Thyroid autoimmunity is a common side effect of interferon-alpha (IFN-alpha) treatment for chronic hepatitis C. There are currently no reliable parameters to predict the occurrence of thyroid dysfunctions in patients undergoing IFN-alpha therapy. CXC chemokine ligand 10 (CXCL10) is a chemokine known to play a role in both thyroid autoimmune disease and hepatitis C virus (HCV) hepatitis. DESIGN: The aim of this study was to evaluate serum CXCL10 levels in HCV patients treated with IFN-alpha in relation to the occurrence of thyroid dysfunctions. Serum CXCL10 levels were assayed in 25 HCV patients (proven to be negative for serum thyroid antibodies) before and during IFN-alpha therapy (2, 4 and 6 months) and in 50 healthy controls. HCV patients were retrospectively selected according to the occurrence of IFN-alpha-induced thyroid dysfunction and were assigned to two groups. Group I included 15 patients who did not develop thyroid antibody positivity or dysfunction; group II included ten patients who showed the appearance of serum thyroid antibodies, followed by clinically overt thyroid dysfunction. RESULTS: Patients with HCV, regardless of the development of thyroid dysfunctions, had significantly higher serum CXCL10 than controls (261.6+/-123.4 vs 80.4+/-33.6 pg/ml; P<0.00001). Pretreatment mean serum CXCL10 levels were significantly higher in Group I versus Group II (308.6+/-130.7 vs 191.1+/-69.4 pg/ml; P<0.05). Groups I and II showed different rates of favourable response to IFN-alpha treatment (33 and 90% respectively). CONCLUSION: Our results suggest that measuring serum CXCL10 before IFN-alpha treatment may be helpful for identifying those patients with higher risk to develop thyroid dysfunction, and require a careful thyroid surveillance throughout the treatment.

Interferon-gamma-inducible alpha-chemokine CXCL10 involvement in Graves' ophthalmopathy: modulation by peroxisome proliferator-activated receptor-gamma agonists.

CONTEXT: CXC alpha-chemokine CXCL10/inducing protein-10 play an important role in the initial phases of autoimmune thyroid disorders. Human thyrocytes in primary culture produce large amounts of CXCL10 when stimulated by interferon-gamma (IFNgamma) and TNFalpha. OBJECTIVE: Serum CXCL10 levels (sCXCL10) were measured in patients with active or inactive Graves' ophthalmopathy (GO). The effects of IFNgamma and TNFalpha stimulation and peroxisome proliferator-activated receptor-gamma (PPARgamma) activation on CXCL10 secretion in primary cultures of thyrocytes, orbital fibroblasts, and preadipocytes were tested. PATIENTS: Sixty consecutive patients with Graves' disease, 60 age- and sex-matched patients with GO, and 60 controls were studied. RESULTS: sCXCL10 was higher (P < 0.0001) in Graves' disease (120 +/- 83 pg/ml; n = 60) and GO (122 +/- 71; n = 60) patients than in age- and sex-matched euthyroid controls (72 +/- 32; n = 60). Among GO patients, sCXCL10 levels were significantly higher in those (n = 14) with active disease (171 +/- 197) than in those with inactive disease (114 +/- 45 pg/ml; P < 0.003). In primary cultures of thyrocytes, retrobulbar fibroblasts and retrobulbar preadipocytes from GO patients, CXCL10 production was absent under basal conditions; dose-dependent secretion of CXCL10 was not induced by TNFalpha alone, whereas stimulation with IFNgamma or TNFalpha plus IFNgamma induced CXCL10 release. Treatment of all cell types with the PPARgamma agonist, rosiglitazone, dose-dependently (0.1-10 microm) suppressed IFNgamma- plus TNFalpha-induced CXCL10 release. CONCLUSIONS: We conclude that in GO, thyrocytes and retrobulbar cell types participate in the self-perpetuation of inflammation by releasing chemokines under the influence of cytokines. PPARgamma activation plays an inhibitory role in this process.

Increased serum CXCL10 in Graves' disease or autoimmune thyroiditis is not associated with hyper- or hypothyroidism per se, but is specifically sustained by the autoimmune, inflammatory process.

OBJECTIVE: Serum CXCL10 (an interferon-gamma-inducible chemokine) levels (sCXCL10) are increased in several autoimmune conditions, including Graves' disease (GD) and autoimmune thyroiditis (AT). Longitudinal assessment of sCXCL10 in autoimmune hypo- or hyperthyroidism has not yet been performed. DESIGN AND METHODS: We longitudinally assayed sCXCL10 in the following groups: thirty-three GD and 11 toxic nodular goiter (TNG) patients when hyperthyroid (Hyper) and when reaching euthyroidism (Eu) with methimazole therapy (MMI) sixty-six AT (33 hypothyroid (Hypo) and 33 Eu) patients, basally and after reaching EU (for Hypo) with levothyroxine (L-T4) therapy twenty-two patients with thyroid cancer (CA) under L-T4-suppressive treatment, of whom 11 were re-evaluated after L-T4 withdrawal for diagnostic WBS, and 11 after recombinant TSH (rhTSH) administration thirty-three healthy controls. RESULTS: At initial evaluation, Hyper GD and AT (Hypo significantly higher than Eu) showed significantly higher mean sCXCL10 than all other groups. MMI treatment led to a significant decrease in sCXCL10 only in GD (not in TNG), while restoration of Eu, in Hypo AT, by L-T4 was not accompanied by significant sCXCL10 change. CA showed sCXCL10 comparable to controls, and both Hypo after L-T4 withdrawal and rhTSH injection had no effect on sCXCL10. CONCLUSIONS: Treatment of Hyper leads to a significant decrease in sCXCL10 only in GD, and this probably depends upon the MMI immunomodulatory effect. L-T4 correction of Hypo is not accompanied by significant modification of sCXCL10 in AT. Increased sCXCL10 is not associated with Hyper or Hypo per se, but is specifically sustained by the autoimmune inflammatory event occurring in both GD and AT.