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)

Paraoxonase 1 (PON1) is a high-density lipoprotein-associated enzyme that is believed to be involved in the protection against oxidative stress. There is evidence that paraoxonase activity is reduced in patients with diabetes and cataract. In the current study, we analyzed mRNA expression of PON1 as well as other members of the paraoxonase family, PON2 and PON3, in human cataractous lens samples. Our results indicate that only PON1 is expressed at the gene and protein levels in human lens tissues. We quantified MDA levels and measured PON1 (paraoxonase/arylesterase) enzymatic activities in subjects suffering from cataract due to aging and diabetes. Decreased PON1 activity was more pronounced in diabetic patients (p< 0.001) compared to senile subjects, which may be due to glycation and increased oxidative insult. To examine the structural alterations that occur in response to glycation, we constructed a three-dimensional model of PON1 and its glycated variant. Glycation at Lys70 and Lys75 is predicted to cause hindrance in binding of substrate to the active site of the enzyme.
 ...
PMID:Expression and activity of paraoxonase 1 in human cataractous lens tissue. 1943 27

Cataract, the lens opacity, is among major causes of blindness in Pakistani population. In recent past, oxidative stress is suggested to play crucial role in loss of transparency. Along with other antioxidants, Paraoxonase 1 (PON1) has also shown decreased activity in patients suffering from cataract. The aim of current study was to examine the possible association of PON polymorphism with predisposition of cataract formation in local population. The study was conducted on 51 cataract patients and 50 control subjects considering all ethical issues. DNA was extracted from whole blood and PON1 polymorphism was identified using tetra primer ARMS-PCR method for both positions L55M and Q192R. Tetra primer ARMS-PCR results revealed that association between L55M polymorphism and cataract was insignificant while 192R genotype PON1 frequency was higher among the people suffering from cataract (78.4%) as compared to control subjects (56%), (odds ratio=2.857, confidence interval=1.197-6.820). Hence, R allele is likely to be a risk factor for cataract with allele frequency (82.3%) and (odds ratio=4.552, confidence interval=1.716-12.073, p-value=0.002). PON1 Q192R polymorphism is likely to be a risk factor for cataract development in Pakistani population while PON1 L55M was not found to be associated with cataract.
...
PMID:Q192R paraoxonase1 polymorphism is a risk factor for cataract in Pakistani population. 2716 46