endothelin-1 and Autoimmune-Diseases

Systemic sclerosis (SSc) is an autoimmune disorder with clinical manifestations resulting from immune activation, fibrosis development and damage of small blood vessels. Although there have been no established treatments for SSc, lots of new treatments targeting organ and pathogenesis are in the process of development. Transforming growth factor (TGF)-beta is a major cytokine involved in the pathogenesis of fibrosis in SSc. The blockade of cell surface molecules capable of activating latent TGF-beta, blockade of ligand by the pan-isoform-specific antibody, soluble TGF-beta receptors and a recombinant latency associated peptide, as well as inhibitors for ALK5 and Smad3 are the potential strategies to abolish the pathological activation of TGF-beta signaling in SSc fibroblasts. Besides TGF-beta, connective tissue growth factor (CTGF)/CCN2, platelet-derived growth factor (PDGF) and endothelin-1 are the candidates for the new therapeutic targets. As for immune dysfunction in SSc, i.v. immunoglobulin infusion, stem cell transplantation and B-cell depletion are potential new therapies under or awaiting a randomized, double-blind, placebo-controlled trial, although their efficacies are still controversial. Phosphodiesterase-5 inhibitors, endothelin receptor antagonists and inhibitors for serotonin signaling are the new therapeutic targets for Raynaud's phenomenon, digital ulceration and pulmonary arterial hypertension in SSc. Imatinib mesylate may be a novel new therapy for fibrosis and vasculopathy in SSc because it reverses the expression levels of Fli1, which is a transcription factor downregulated in SSc through an epigenetic mechanism and is likely to be involved in the development of fibrosis and vasculopathy in this disease. Potential therapeutic targets other than those described above are also reviewed.

Topics: Animals; Autoimmune Diseases; B-Lymphocytes; Benzamides; Connective Tissue Growth Factor; Endothelin Receptor Antagonists; Endothelin-1; Humans; Imatinib Mesylate; Immunoglobulins; Mice; Phosphodiesterase 5 Inhibitors; Piperazines; Platelet-Derived Growth Factor; Pyrimidines; Randomized Controlled Trials as Topic; Receptors, Transforming Growth Factor beta; Scleroderma, Systemic; Selective Serotonin Reuptake Inhibitors; Smad3 Protein; Transforming Growth Factor beta

Endothelin (ET)-1 is a potent renal vasoconstrictor with pro-inflammatory, profibrotic and mitogenic potential. Animal studies support a pathogenetic contribution of ET-1 and its cognate receptors in several renal manifestations of autoimmune disorders. However, data in humans are limited. The present minireview thus summarizes the observations available in humans. Similar to animal models, ET-1 is overexpressed in glomerular and tubulointerstitial lesions, which is reflected by an increased urinary excretion of ET-1. Since antagonizing the ET system has beneficial effects in experimental models, this approach may be translated to the human kidney, thus counteracting vasoconstriction, inflammation and extracellular matrix deposition during the course of human autoimmune disease.

Topics: Autoimmune Diseases; Endothelin-1; Humans; Inflammation; Kidney Diseases; Receptors, Endothelin; Vasoconstriction

The aim of this study was to determine the role of endothelin-1 (ET-1), a molecule involved in multiple vascular and fibrosing abnormalities, as a biomarker of interstitial lung disease (ILD), as well as its use for the differential diagnosis between idiopathic pulmonary fibrosis (IPF) and ILD associated with autoimmune diseases (AD-ILD), using a large and well-defined cohort of patients with ILD. A total of 112 patients with IPF, 91 patients with AD-ILD (28 rheumatoid arthritis (RA), 26 systemic sclerosis, 20 idiopathic inflammatory myositis and 17 interstitial pneumonia with autoimmune features) and 44 healthy controls were included. ET-1 serum levels were determined by enzyme-linked immunosorbent assay. A significant increase in ET-1 levels was found in patients with IPF compared to controls. Likewise, AD-ILD patients also showed higher ET-1 levels than controls when the whole cohort was stratified by the type of AD. Similar ET-1 levels were found in IPF and AD-ILD patients, regardless of the underlying AD. Interestingly, increased ET-1 levels were correlated with worse lung function in IPF and RA-ILD patients. Our study supports that serum ET-1 may be useful as a biomarker of ILD, although it could not help in the differential diagnosis between IPF and AD-ILD. Moreover, ET-1 levels may be associated with ILD severity.

Topics: Arthritis, Rheumatoid; Autoimmune Diseases; Biomarkers; Endothelin-1; Humans; Idiopathic Pulmonary Fibrosis; Lung Diseases, Interstitial

Pulmonary arterial hypertension is often associated with connective tissue disease. Although there are some animal models of pulmonary hypertension, an autoimmune disease-based model has not yet been reported. MRL/lpr mice, which have hypergammaglobulinemia, produce various autoimmune antibodies, and develop vasculitis and nephritis spontaneously. However, little is known about pulmonary circulation in these mice. In the present study, we examined the pulmonary arterial pressure in MRL/lpr mice.. We used female MRL/lpr mice aged between 12 and 14 weeks. Fluorescent immunostaining showed that there was no deposition of immunoglobulin or C3 in the lung tissue of the MRL/lpr mice. Elevation of interferon-γ and interleukin-6 was recognized in the lung tissue of the MRL/lpr mice. Right ventricular systolic pressure, Fulton index and the ratio of right ventricular weight to body weight in the MRL/lpr mice were significantly higher than those in wild type mice with same background (C57BL/6). The medial smooth muscle area and the proportion of muscularized vessels in the lung tissue of the MRL/lpr mice were larger than those of the C57BL/6 mice. Western blot analysis demonstrated markedly elevated levels of prepro-endothelin-1 and survivin as well as decreased endothelial nitric oxide synthase phosphorylation in the lung tissue of the MRL/lpr mice. Terminal deoxynucleotidyl-transferase-mediated dUTP nick end-labeling assay showed the resistance against apoptosis of pulmonary arterial smooth muscle cells in the MRL/lpr mice.. We showed that MRL/lpr mice were complicated with pulmonary hypertension. MRL/lpr mice appeared to be a useful model for studying the mechanism of pulmonary hypertension associated with connective tissue diseases.

Topics: Animals; Apoptosis; Autoimmune Diseases; Blood Pressure; Complement C3; Cytokines; Disease Models, Animal; Endothelin-1; Heart Ventricles; Hypertension, Pulmonary; Immunoglobulin G; Inhibitor of Apoptosis Proteins; Lung; Mice; Mice, Inbred C57BL; Mice, Inbred MRL lpr; Myocytes, Smooth Muscle; Nitric Oxide Synthase Type III; Pulmonary Artery; Repressor Proteins; Survivin

Myocarditis and subsequent dilated cardiomyopathy are major causes of heart failure in young adults. Experimental autoimmune myocarditis (EAM) is a mouse model of post-infectious myocarditis and inflammatory cardiomyopathy. The pathological role of endothelin (ET) in myocarditis has not been elucidated.. EAM was induced by immunization of cardiac myosin peptide with complete Freund's adjuvant on days 0 and 7 in BALB/c mice. An ETA/ETB dual receptor antagonist, SB209670, was administered by a continuous infusion from a subcutaneous pump for 2 weeks.. An increase in the heart-to-body weight ratio was observed in SB209670-treated mice compared with vehicle-treated mice. Heart pathology in SB209670-treated mice was remarkable for gross inflammatory infiltration, in contrast to the lesser inflammation in the hearts of vehicle-treated mice. We found that an ET blockade decreased the number of Foxp3(+) regulatory T cells in the heart. The ET blockade also inhibited the expression of the suppressor of cytokine signaling 3 that plays a key role in the negative regulation of both Toll-like receptor- and cytokine receptor-mediated signaling. EAM is a CD4(+) T cell-mediated disease. CD4(+) T cells isolated from SB209670-treated EAM mice produced less IL-10 and more inflammatory cytokines, IL-6 and IL-17, than those isolated from vehicle-treated mice.. The ET receptor antagonist exacerbated autoimmune myocarditis in mice. Our novel findings suggest that ET may play an important role in the regulation of inflammation in myocarditis.

Topics: Animals; Autoimmune Diseases; CD4-Positive T-Lymphocytes; Cell Differentiation; Chemokines; Disease Progression; Endothelin Receptor Antagonists; Endothelin-1; Flow Cytometry; Gene Expression Regulation; Lymph Nodes; Mice, Inbred BALB C; Myocarditis; Myocardium; Myosins; Receptor, Endothelin A; Receptor, Endothelin B; Suppressor of Cytokine Signaling 3 Protein; Suppressor of Cytokine Signaling Proteins

In order to test the hypothesis that treatment with quercetin at a dose of 10 mg/kg protects from the progression of experimental autoimmune myocarditis (EAM) to dilated cardiomyopathy (DCM), we have used the rat model of EAM induced by porcine cardiac myosin. Our results identified that the post-myocarditis rats suffered from elevated endoplasmic reticulum (ER) stress and adverse cardiac remodelling in the form of myocardial fibrosis, whereas the rats treated with quercetin have been protected from these changes as evidenced by the decreased myocardial levels of ER stress and fibrosis markers when compared with the vehicle-treated DCM rats. In addition, the myocardial dimensions and cardiac function were preserved significantly in the quercetin-treated rats in comparison with the DCM rats treated with vehicle alone. Interestingly, the rats treated with quercetin showed significant suppression of the myocardial endothelin-1 and also the mitogen activated protein kinases (MAPK) suggesting that the protection offered by quercetin treatment against progression of EAM involves the modulation of MAPK signalling cascade. Collectively, the present study provides data to support the role of quercetin in protecting the hearts of the rats with post myocarditis DCM.

Topics: Animals; Apoptosis; Autoimmune Diseases; Biomarkers; Cardiac Myosins; Cardiotonic Agents; Cytochromes c; Endoplasmic Reticulum Stress; Endothelin-1; Fibrosis; Heart; Male; MAP Kinase Signaling System; Myocarditis; Myocardium; Organ Size; Osteopontin; Oxidative Stress; Quercetin; Rats; Rats, Inbred Lew; Ventricular Remodeling

Discovery of treatments to protect axonal function of neurons and prevent permanent disability associated with progressive multiple sclerosis (MS) has faced the uphill challenge of assessing relatively small changes in accumulated axon damage within a background environment that is disorganized by CNS inflammation. We hypothesized that transient immunosuppression after initiation of MS-like autoimmune mechanisms would disassociate development of MS-like myelinated axon pathology from development of CNS inflammation in a rat model of autoimmune optic neuritis (AON). A rat model of myelin oligodendrocyte glycoprotein peptide-induced AON was transiently treated (on days 3-7 after antigen exposure) with 5-(4-phenylbutoxy)psoralen (PAP-1), an immunomodulatory drug previously shown specifically to suppress proliferation of effector memory T-cells and immunoglobulin class-switched B-cells. Thirteen days after antigen exposure, optic nerves were harvested for quantitative assessment of 12 MS-associated pathologies using microfluorimetry. With one exception, the immunoreactivities (-ir) for eight markers of MS-like neuroinflammation and immune infiltration were significantly reduced (P < 0.05) by transient PAP-1 treatment, often to levels significantly below those detected in normal control rat optic nerves. With one exception, four immunoreactive markers of MS-like myelinated axon pathology were detected at levels indicating increased axon/myelin pathology compared with vehicle-treated rats with AON (P < 0.05). These data suggest the conclusion that early causative mechanisms in CNS autoimmunity initiate signaling mechanisms that diverge into two separate pathways, one that is strongly associated with inflammatory responses and one that is associated predominantly with disturbed axon-myelin interactions and impaired fast axonal transport.

Topics: Animals; Autoimmune Diseases; Endothelin-1; Female; Ficusin; Inflammation; Interleukin-1; Myelin Proteins; Myelin-Associated Glycoprotein; Myelin-Oligodendrocyte Glycoprotein; Optic Neuritis; Pancreatitis-Associated Proteins; Rats; Rats, Inbred BN