Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.3.1 (NADPH oxidase)
 11,281 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Morphological and functional alterations in Hashimoto's thyroiditis (HT) are predominantly mediated by Th1 cytokines through apoptotic cell death. This ultimate step could be preceded by functional injuries in thyroid hormone synthesis. The action of two Th1 cytokines (IL-1alpha/IFN-gamma) on thyroperoxidase (TPO) and thyroid oxidase (ThOXs) expression was tested in human thyrocytes isolated from normal tissues, Graves' disease (GD) tissues, and autonomous toxic nodules. There was no evidence of cell death. Nitric oxide (NO) release was induced by cytokines but was absent when NG-nitro-L-arginine methyl ester (L-NAME) was coincubated. When thyrotropin (TSH)-incubated normal and GD thyrocytes were treated with IL-1alpha/IFN-gamma, TPO and ThOXs protein and mRNA expression dropped, a decrease partially prevented by L-NAME, suggesting that NO acts as a mediator of Th1 effects. In thyrocytes from autonomous toxic nodules, the high level of TPO and ThOXs protein expression was not influenced by TSH or by cytokines, a finding partially reproduced when normal thyrocytes were treated with increasing concentrations of TSH. In conclusion, incubation of normal or GD thyrocytes with Th1 cytokines induces a significant reduction in TSH-increased expression of both TPO and ThOXs, an effect partially mediated by NO. The thyroid cell function can therefore be severely affected in HT, even when cells remain viable. In autonomous toxic nodules, cells become partially insensitive to exogenous Th1 cytokines.
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PMID:Expression of TPO and ThOXs in human thyrocytes is downregulated by IL-1alpha/IFN-gamma, an effect partially mediated by nitric oxide. 1647 76

Autoimmune thyroiditis, also known as chronic lymphocytic or Hashimoto's thyroiditis, is characterized by infiltration of the thyroid gland by inflammatory cells and production of autoantibodies to thyroid-specific antigens thyroglobulin and thyroperoxidase. It is accompanied by hypothyroidism due to destruction and eventual fibrous replacement of the follicle cells. Autoimmune thyroiditis is clearly multifactorial in etiology with genetic and environmental factors contributions. Excess dietary Iodine can exacerbate thyroiditis in genetically susceptible hosts such as the NOD.H2(h4) mouse. In this mouse excess dietary iodine leads to an increased immunogenicity of the thyroglobulin molecule and enhanced expression of ICAM-1 on thyroidal follicle cells. We present evidence here that ICAM-1 expression is enhanced by the elevated generation of reactive oxygen species (ROS). The anti-oxidant diphenyleneiodium (DPI), an inhibitor of NADPH oxidase, reduced both the generation of ROS and of ICAM-1 expression in cultures of NOD.H2(h4) mouse thyrocytes. These results suggest that antioxidants may have therapeutic value in preventing autoimmune thyroiditis.
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PMID:Autoimmune thyroiditis and ROS. 1862 41

The thyroid gland is a unique endocrine organ that requires hydrogen peroxide (H(2)O(2)) for thyroid hormone formation. The molecule for H(2)O(2) production in the thyroid gland has been known as dual oxidase 2 (DUOX2). Recently, NADPH oxidase 4 (NOX4), a homolog of the NOX family, was added as a new intracellular source of reactive oxygen species (ROS) in the human thyroid gland. This review focuses on the recent progress of the DUOX system and its possible contribution to human thyroid diseases. Also, we discuss human thyroid diseases related to abnormal H(2)O(2) generation. The DUOX molecule contains peroxidase-like and NADPH oxidase-like domains. Human thyroid gland also contains DUOX1 that shares 83% similarity with the DUOX2 gene. However, thyroid DUOX1 protein appears to play a minor role in H(2)O(2) production. DUOX proteins require DUOX maturation or activation factors (DUOXA1 or 2) for proper translocation of DUOX from the endoplasmic reticulum to the apical plasma membrane, where H(2)O(2) production takes place. Thyroid cells contain antioxidants to protect cells from the H(2)O(2)-mediated oxidative damage. Loss of this balance may result in thyroid cell dysfunction and thyroid diseases. Mutation of either DUOX2 or DUOXA2 gene is a newly recognized cause of hypothyroidism due to insufficient H(2)O(2) production. Papillary thyroid carcinoma, the most common thyroid cancer, is closely linked to the increased ROS production by NOX4. Hashimoto's thyroiditis, a common autoimmune thyroid disease in women, becomes conspicuous when iodide intake increases. This phenomenon may be explained by the abnormality of iodide-induced H(2)O(2) or other ROS in susceptible individuals. Discovery of DUOX proteins and NOX4 provides us with valuable tools for a better understanding of pathophysiology of prevalent thyroid diseases.
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PMID:Dual oxidase, hydrogen peroxide and thyroid diseases. 2040 74

Recent epidemiological studies recognized a steady increase in the incidence of different autoimmune endocrine disorders, including autoimmune thyroid disease (AITD). The etiology of AITD is multifactorial and involves genetic and environmental factors and apparently with a strong preponderance in females. There are mainly two types of AITD, Graves' disease and Hashimoto's disease and both of these show strong association in age groups above 45-50 years. Among environmental factors smoking and alcohol have significant effects, both protective as well as for aggravating the disease, even though the precise nature of these effects are not clearly known. There are elevated levels of circulating antibodies against the thyroid proteins, mainly thyroid oxidase, thyroglobulin and thyroid stimulating hormone receptor, in patients with Graves' disease or Hashimoto's disease. Linkage and association studies in AITD identified several major genes that are relevant for the onset of AITD, including the thyroid-specific genes, thyroglobulin and thyroid-stimulating hormone receptor and also many immune-regulatory genes. In this review we addressed many aspects of AITD including disease mechanisms, involved thyroid antigens, environmental factors and genetic factors.
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PMID:Autoimmune thyroid disease: mechanism, genetics and current knowledge. 2553 30