Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In a previous work we characterized a major epitope of thyroid peroxidase (TPO), which was recognised by 66% of 157 patients with autoimmune thyroid disease (AITD) and 9 out of 50 patients with non-thyroidal autoimmune disease (NTAID) 6 of whom had antibodies to the gastric parietal cell antigen (PCA). In the present study we have affinity purified C2 antibodies and demonstrated that they bind to the native TPO enzyme in a radioimmunoassay (RIA). We have measured antibodies to the C2 peptide and a second TPO peptide, C21, in enzyme-linked immunosorbent assays (ELISA) in 30 patients with NTAID all of whom have antibodies to the gastric PCA, having first determined the incidence of antibodies to C21 in 98 patients with AITD who do not have antibodies to the gastric PCA. 58% of patients with AITD have antibodies to C21, a peptide of TPO which overlaps C2 by 21 amino acids in the region containing an 11 residue fragment which is very similar to a fragment of the H+ K+ ATPase, which has recently been shown to be a major component of the gastric PCA. In patients having NTAID and antibodies to the gastric PCA, 60% are positive for C2 Ab and 100% for C21 Ab, which is suggestive of an epitope shared by TPO and H+ K+ ATPase, corresponding to TPO 659----669 and H+ K+ ATPase 177----187. We conclude that C2 antibodies are heterogenous and comprise activities which bind to the intact enzyme and activities binding to an epitope which may be common to TPO and H+ K+ ATPase.
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PMID:Studies with recombinant autoepitopes of thyroid peroxidase: evidence suggesting an epitope shared between the thyroid and the gastric parietal cell. 171 10

The recently cloned sodium-iodide symporter (NIS) represents a key molecule for thyroid function by efficiently accumulating iodide from the circulation into the thyrocyte against an electrochemical gradient. This uptake requires energy, is coupled to the action of Na+/K+-ATPase, and stimulated by TSH, the main hormone regulating thyroid-specific functions. NIS mutations are found in congenital hypothyroidism, and potential defects in the NIS gene, its expression, or function of the NIS protein are currently under investigation in various thyroid diseases. Increased NIS expression has been found in autonomous adenoma and Graves' disease, decreased levels of NIS protein and/or mRNA were observed in Hashimoto's disease, cold nodules, most thyroid cancers and cell lines derived therefrom. Autoantibodies directed against NIS have been identified in autoimmune thyroid disease and blocking antibodies isolated from sera of patients with Hashimoto's disease inhibit NIS function in NIS-transfected CHO cells. NIS mRNA expression can be up-regulated by retinoic acid in human thyroid carcinoma cell lines whereas retinoic acid treatment decreases NIS expression and function in differentiated rat thyroid FRTL-5 cells. Apart from thyrocytes, NIS is also expressed in other tissues known to transiently accumulate radioiodide, albeit at much lower levels, requiring RT-PCR for detection of the transcript. Diagnostic and therapeutic implications of the recent cloning of the human NIS gene such as development of NIS-directed drugs, ligands, antibodies, vaccines, gene therapeutic approaches combining NIS targeting and expression together with the long-established, efficient and safe method of radioiodide therapy are discussed both for application to thyroid related diseases and carcinoma, and non-thyroid benign and malignant diseases. Apart from these therapeutic and diagnostic perspectives the availability of the NIS gene will also open new opportunities to develop sensitive and homologous diagnostic test systems to identify factors involved in autoimmune thyroid disease, evolution of goitre, adenoma and thyroid cancer as well as NIS-directed new drugs. Advanced and sophisticated molecular diagnostic approaches (RT-PCR from fine needle aspirations, screening for mutations, analysis of gene defects) are already developed for NIS and will complement or overcome some established procedures in thyroid diagnostics.
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PMID:Implications of the molecular characterization of the sodium-iodide symporter (NIS). 986 44

Juvenile patients affected with autoimmune thyroid disorders showed a 14-21% prevalence of parietal cell antibodies (PCA) reacting against the H+/K+-ATPase of the gastric parietal cells. PCA are the principal immunological markers of atrophic body gastritis (ABG).ABG is characterized by loss of oxyntic glands, achlorhydria, and hypergastrinemia. The aim of this study was to determine whether PCA positivity could be associated with biochemical and histological manifestations of gastric autoimmunity in juvenile patients with autoimmune thyroid disease (AITD). We studied 129 children (96 females and 33 males) with chronic lymphocytic thyroiditis (n = 115) or Graves' disease (n = 14). Mean age at diagnosis of AITD was 9.7 +/- 3.3 yr, and mean age at sampling was 12.3 +/- 3.7 yr. We determined PCA and Helicobacter pylori antibodies, gastrin, and pepsinogen I plasma levels. Gastroscopy with multiple biopsies was carried out in a subgroup of patients with PCA positivity. We found that 30% of children had detectable PCA. Hypergastrinemia was found in 45% of the PCA-positive children (range, 40-675 pg/ml) vs. 12% of PCA-negative children (range, 35-65 pg/ml; P < 0.001). Eighteen patients with PCA positivity underwent gastroscopy; eight of these children had normogastrinemia, which showed no signs of ABG, and 10 children had hypergastrinemia, of whom five had mild to severe ABG. Our study shows that autoimmune gastritis is an early event in juvenile AITD with detectable PCA. Gastrin plasma level is a reliable marker of gastric atrophy.
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PMID:Early manifestations of gastric autoimmunity in patients with juvenile autoimmune thyroid diseases. 1547 89