Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024141 (systemic lupus erythematosus)
 44,322 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

S-carboxy-L-methylcysteine was used to assess the activity of the S-oxidation pathway of sulphur metabolism in 35 patients with systemic lupus erythematosus (SLE); 25 (71%) showed impaired sulphoxidation and 21 (60%) produced virtually no sulphoxides, compared with 17 (36%) and 2 (4%), respectively, of 47 healthy controls. The substrate/product ratio of cysteine oxygenase (plasma cysteine/sulphate) was significantly higher in SLE patients than in controls (median [interquartile range] 362 [224-588] vs 65 [44-111]; p less than 0.00001). The alternative pathway of sulphur metabolism, S-methylation, catalysed by thiolmethyltransferase, was not impaired in the SLE patients. There is a biochemical difference in sulphur metabolism between SLE and rheumatoid arthritis, since both pathways are impaired in the latter disorder.
 ...
PMID:Abnormal sulphur oxidation in systemic lupus erythematosus. 134 15

As a result of the implication of N-oxidized procainamide metabolites in drug-related lupus (DRL), the electrochemical behaviour of these compounds was investigated and a coulometric synthesis of the nitroso derivative developed using a previously described carbon packed bed bulk electrolysis flow cell. The electrochemical characterization of the parent p-substituted aromatic amine and the N-oxidized derivatives was achieved through systematic comparison with previously well described aromatic amine and nitro systems using cyclic voltammetry and liquid chromatography with electrochemical detection (LC-EC). Chromatographically assisted hydrodynamic voltammetry indicated current limiting plateau potentials of 0.45 and -0.2 V versus Ag/AgCl, respectively, for synthetically prepared procainamide hydroxylamine and electrolytically prepared nitrosoprocainamide. Reaction characterization and binding behaviour is described for each of the procainamide metabolites following in vitro incubations with cysteine, glutathione, ascorbic acid and mouse haemoglobin.
 ...
PMID:Electrochemical investigations of immunologically reactive procainamide metabolites. 209 15

Factors that potentially affect the generation of excess low molecular weight DNA (LMW-DNA) in cultured phytohemagglutinin (PHA)-stimulated lymphocytes of patients with systemic lupus erythematosus (SLE) were studied because this species of DNA is consistently found and this DNA may play a role in the pathogenesis of the disease. Superoxide dismutase (SOD; 0.05 mg/mL), a scavenger of free radical oxygen, decrease LMW-DNA formation in lymphocytes by 22%. Co-cultivation with cysteamine, a second scavenger of free radical oxygen and a sulfhydryl radioprotective agent, resulted in a 32% decrease in the generation of excess LMW-DNA at a concentration of 0.5 x 10(-3) mol/L and largely prevented its formation at 1.0 x 10(-3) mol/L. Other free radical scavengers (catalase, mannitol, vitamins C and E), cyclooxygenase inhibitors (ibuprofen and aspirin), a xanthine oxidase inhibitor (allopurinol), and an iron chelator (desferoxamine) did not affect excess LMW-DNA formation. Glutathione (1 x 10(-3) mol/L) had no effect and cysteine was toxic. Because scavengers of free radicals might be useful in the therapy of lupus, a trial of cysteamine (30 to 60 mg/kg/d) was administered to six acutely ill patients with SLE. A therapeutic benefit was not demonstrated, and some patients had exacerbation of disease. Lymphocyte cell growth from control and lupus subjects was stimulated when cysteamine, 1 x 10(-5) to 1 x 10(-4) mol/L was added to the media, but inhibited at concentrations of 2 x 10(-4) mol/L or greater. These studies suggest that the autooxidation and toxicity of high-dose cysteamine preclude its therapeutic use as a free radical scavenger.
 ...
PMID:Scavengers of free radical oxygen affect the generation of low molecular weight DNA in stimulated lymphocytes from patients with systemic lupus erythematosus. 224 68

Because of the implication of N-oxidized metabolites of procainamide in the induction of drug-related lupus, we have studied the electrochemical behavior of these metabolites and developed an electrochemical synthesis of nitrosoprocainamide. This synthesis was developed using procainamide hydroxylamine as the starting material which was oxidized to the nitroso species at an applied potential of 700 mV vs Ag/AgCl using a carbon packed bed bulk electrolysis flow cell. Conversion efficiencies of greater than 95% were achieved with this method. Subsequent studies with a chemically diverse series of biocompounds were used to investigate possible reactions between the procainamide hydroxylamine and nitroso species and these selected molecules. Only antioxidants such as cysteine, glutathione and ascorbic acid were found to react with the nitroso compound as determined by electrochemical methods, and this reaction was characterized as primarily a simple redox reaction at physiological pH. Animal studies conducted with murine spleen cells incubated with mitogens and various procainamide compounds demonstrated that the N-oxidized metabolites are the active immunopharmacologic agents.
 ...
PMID:Electrochemical determination of N-oxidized procainamide metabolites and functional assessment of effects on murine cells in vitro. 245 6

EEA1, a 162-kDa autoantigen associated with subacute cutaneous systemic lupus erythematosus, is a coiled-coil protein localized to early endosomes and cytosol. At its C terminus, the protein contains a cysteine-rich motif, which is shared with Vps27, Fab1, and Vac1, yeast proteins implicated in membrane traffic (Mu, F. T., Callaghan, J. M., Steele-Mortimer, O., Stenmark, H., Parton, R. G., Campbell, P. L., McCluskey, J., Yeo, J. P., Tock, E. P., and Toh, B. H. (1995) J. Biol. Chem. 270, 13503-13511). Here we show that this motif constitutes a genuine zinc binding domain, which we term the FYVE finger (based on the first letters of four proteins containing this motif). Profile-based data base searches identified the FYVE finger in 11 distinct proteins. The FYVE finger-containing C terminus of EEA1 was found to bind 2 mol equivalents of Zn2+. Mutations of conserved histidine and cysteine residues in the FYVE motif independently reduced zinc binding to 1 mol equivalent. Confocal immunofluorescence microscopy of transfected HEp2 cells revealed that the C-terminal part (residues 1277-1411) of EEA1 colocalizes extensively with a GTPase-deficient mutant of the early endosomal GTPase Rab5, while deletion of the FYVE finger or mutations that interfere with zinc binding cause a cytosolic localization. These results implicate the FYVE finger in the specific localization of EEA1 to endosomes.
 ...
PMID:Endosomal localization of the autoantigen EEA1 is mediated by a zinc-binding FYVE finger. 879 41

Immunoglobulin A-alpha-1-antitrypsin complex (IgA-AT) is a nonimmune complex formed by disulphide bonding between an active thiol group available on the cysteine residue of alpha heavy chains of IgA and a cysteine in position 232 of alpha l-antitrypsin in single polypeptide chain. The level of the complex can easy be determined using the ELISA method and findings are expressed in arbitrary units. In the healthy adults' sera the IgA-AT complex level is lower than 0.4 arbitrary unit. The elevated levels of the complex were found in a number of rheumatic diseases. In 50% of SLE patients, its levels are increased, particularly in those with current central nervous system involvement. Similarly, in approximately 50% sera derived from RA patients they are also found to be higher. Their presence correlates with anatomical progression of the disease. IGA-AT complex is found in RA (in 90% of cases) but not in the osteoarthritis synovial fluid. Our findings can be applied in clinical praxis in differential diagnosis of early rheumatoid arthritis and osteoarthritis. The IGA-AT complex can be also found in ankylosing spondylitis. The complex has been determined in a relatively large number of IgA myeloma sera. In 30% of the cases its levels were 10-fold higher than the upper limit for healthy adults.
 ...
PMID:Immunoglobulin A--alpha-1-antitrypsin complex in rheumatic diseases. 930 36

CD5 is a 67 kDa type I glycoprotein which belongs to the Scavenger Receptor Cysteine-Rich (SRCR) family of receptors. This family includes either cell-surface (e.g. CD6) or secreted (e.g. Spalpha) proteins implicated in the development of the immune system and the regulation of immune responses. In this study, we purified and characterised a circulating natural soluble CD5 form (nsCD5) which is indistinguishable (in apparent molecular mass, glycosylation pattern, and antibody reactivity) from a recombinant soluble CD5 form (rsCD5) composed of the three extracellular SCRC domains. The nsCD5 is a N-glycosylated 52 kDa molecule present in normal human serum and in supernatants of in vitro phorbol ester- and CD3-stimulated peripheral blood mononuclear cells. The nsCD5 concentration in sera from healthy donors is relatively low (median 1.75 ng/ml, rn=166) and is similar to that found in sera from patients suffering of various autoimmune (systemic lupus erythematosus, primary Sjogren syndrome, rheumatoid arthritis) and non-autoimmune (chronic renal failure, B-cell chronic lymphocytic leukemia) disorders. In vitro experiments indicate that nsCD5 is released by proteolytic cleavage of the membrane form. These results represent the first evidence of proteolytic release of a transmembrane SRCR family member following cell activation.
 ...
PMID:Identification of a natural soluble form of human CD5. 1048 39

The cDNA clones encoding immunoglobulin (Ig) light (L) chain variable (V) region associated with constant (C) region were isolated from yellowtail (Seriola quinqueradiata) kidney by expressed sequence tag analysis (accession numbers: AB062619-AB062668, AB064322). The sequences of both VL and CL region contain well-conserved cysteine residues important for intra- and inter-domain interaction in mammals. Comparisons of the amino acid sequence of the CL domain with those of other species showed a high degree of similarity, with 88.3%, 59.8%, and 60.6% to those of wolf fish (Anarhichas lupus), rainbow trout IgL I isotype (Oncorhynchus mykiss) and channel catfish G isotype (Ictalurus punctatus), respectively. Multiple sequence alignments of the CL domain with those of higher vertebrates, however, did not readily allow it to be classified as kappa or lambda isotypes. Furthermore, the pI, hydrophobicity and variability of yellowtail VL regions were studied in 65 cDNA clones and the diversity was observed in CDR1, CDR2 and CDR3 regions.
 ...
PMID:Cloning, sequence and variability analysis of expressed immunoglobulin light chain genes from yellowtail Seriola quinqueradiata. 1254 26

The type one complement receptor (CR1) contains a variable number of binding domains for C3b and C4b, formed through a nearly identical set of repeating units known as short consensus repeats (SCRs). Each SCR contains four cysteines that, by forming two disulfide bonds, impart a conformation critical for function. In this study, we identified a CR1 single nucleotide polymorphism (1597C>T) that results in an additional cysteine (483R>C) in SCR 8 of the N-terminal C3b/C4b binding domain, and occurring sporadically in corresponding SCRs of other repeated C3b/C4b binding domains. The normal carrier frequency for 483-C was 6.3% in 175 African Americans, and 2.4% in 153 Caucasians. In expression constructs containing one C3b/C4b binding domain, the 483-C residue reduced binding to C3b, C3bi, and C4b by over 80% (each p<0.0001), versus the wildtype construct. Full-length CR1 from 483-C carriers also exhibited reduced binding to C3b and C4b, although the effect was influenced by the total number of binding domains present. Race-matched comparisons between SLE patients (86 African Americans, 228 Caucasians) and the normal cohort showed that 483-C carrier status alone is not a risk factor for SLE or lupus nephritis. The physiological role of this polymorphism remains to be determined.
 ...
PMID:A polymorphism in the type one complement receptor (CR1) involves an additional cysteine within the C3b/C4b binding domain that inhibits ligand binding. 1746 2

The architectural chromosomal protein high-mobility group box 1 protein (HMGB1) acts as an alarmin when released from cells. It is involved in the pathogenesis of inflammatory and autoimmune diseases. HMGB1 can undergo post-translational modifications including oxidation. However, the mechanisms and functional relevance of HMGB1 oxidation are not yet understood. Increased concentrations of reactive oxygen species (ROS) have been reported during apoptosis and necrosis. Hence, we investigated the oxidative status of HMGB1 in dead cells. Immunoblot analyses under reducing and non-reducing conditions revealed that HMGB1 is oxidized in dead cells. Moreover, tagging of oxidized cysteine residues by a maleimide moiety linked to polyethylene glycol showed that HMGB1 passively released from primary and secondary necrotic cells was predominantly oxidized. Also HMGB1 in plasma of patients with systemic lupus was reversibly oxidized. In conclusion, HMGB1 undergoes reversible oxidative modifications at cysteine residues during cell death, which may modulate its biological properties.
 ...
PMID:Oxidation of the alarmin high-mobility group box 1 protein (HMGB1) during apoptosis. 1981 Dec 84


1 2 3 Next >>