Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We previously found that Ca2+ concentrations, inducible nitric oxide synthase (iNOS) mRNA, and protein expression in lenses of the Shumiya cataract rat (SCR) increase with the development of cataracts. In this study, we investigated the change in Ca2+-ATPase activities and ATP levels in the human lens epithelial cell line SRA 01/04 (HLE cells) with the stimulation of interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS). Expression levels of iNOS mRNA in HLE cells, which were determined using semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and quantitative real-time RT-PCR methods, increased during stimulation with IFN-gamma (1000 IU) and LPS (100 ng/ml). NO release from HLE cells, expressed as the sum of NO2- and NO3- levels, increased with the increase in iNOS expression levels. Ca2+-ATPase activities increased and ATP levels decreased in HLE cells stimulated with the combination of IFN-gamma and LPS. Furthermore, both diethyldithiocarbamate and aminoguanidine attenuated the increase in Ca2+-ATPase activities and the decrease in ATP levels. These results suggest that excessive production of NO may cause mitochondrial damage, resulting in an increased Ca2+ concentration in the lens. The increase in Ca2+ concentration in the lens may increase Ca2+-ATPase activities.
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PMID:Inhibitors of inducible nitric oxide synthase prevent damage to human lens epithelial cells induced by interferon-gamma and lipopolysaccharide. 1701 54

Asymmetric dimethylarginine (ADMA) is an endogenous NO synthase (NOS) inhibitor whose production is enhanced by oxidative stress. Recent studies have shown that ADMA may also directly stimulate the production of reactive oxygen species (ROS) by up-regulation of the renin-angiotensin system independently of NOS inhibition. In this study, to investigate the clinical association of ADMA with diabetic retinopathy, we evaluated the levels of ADMA and NO oxides (NO2- and NO3-) in serum and aqueous humor obtained during cataract surgery from non-diabetic subjects (n = 21) and diabetic patients (n = 17). We found that the ADMA existed in aqueous humor and its level was similar to that in serum. The ADMA levels in both serum and aqueous humor were higher in diabetic patients, especially those with severe retinopathy, than in the non-diabetic group (serum ADMA: 0.67 +/- 0.26 vs. 0.53 +/- 0.08 micromol/l, p<0.05; aqueous humor ADMA: 0.55 +/- 0.20 vs. 0.32 +/- 0.16 micromol/l, p<0.05). Also, the aqueous humor level of ADMA, but not the serum level, was correlated with HbA1c on analysis of all the patients (R = 0.33, p<0.05 by simple regression analysis). However, a correlation between the ADMA levels in serum and aqueous humor was not observed in either the non-diabetic group or the diabetic group. Furthermore, serum and aqueous humor levels of NOx did not differ between the two groups, and no correlation with ADMA levels was observed in either group. These results suggest that ROS production may be enhanced in the eyes of diabetics. Since ADMA may act to potentiate ROS production independently of its inhibition of NOS, further investigation is required to clarify the possible contribution of ADMA to the development or progression of retinopathy.
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PMID:Asymmetric dimethylarginine (ADMA) in the aqueous humor of diabetic patients. 1737 59