ABSTRACT
We were intrigued to analyze donor eyes of two individuals without retinopathy even after 40 years of type 2 diabetes mellitus. Targeted molecular factors associated with angiogenesis and the key antioxidant enzymes in retinal tissue were analyzed. Accordingly PEDF, Adiponectin and Paraoxonase 2 showed augmented mRNA expression in both the retina with no significant change in VEGF expression. Vitreous showed increased PEDF protein in donor 1 and Adiponectin in donor 2 with no change in VEGF protein. This study highlights the profile of specific molecular factors that contribute to the non-development of diabetic retinopathy changes in these individuals.
Subject(s)
Adiponectin/biosynthesis , Aryldialkylphosphatase/biosynthesis , Diabetes Mellitus, Type 2/diagnosis , Eye Proteins/biosynthesis , Gene Expression Regulation , Nerve Growth Factors/biosynthesis , Retina/pathology , Serpins/biosynthesis , Tissue Donors , Adiponectin/genetics , Aged, 80 and over , Aryldialkylphosphatase/genetics , Biomarkers/metabolism , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Eye Proteins/genetics , Female , Humans , Male , Middle Aged , Nerve Growth Factors/genetics , Oxidative Stress , RNA/genetics , Retina/metabolism , Retinal Diseases , Serpins/geneticsABSTRACT
OBJECTIVES: High levels of plasma homocysteine have been reported to be toxic to the vascular endothelium, thereby creating an environment of hypercoagulability and occlusion. Elevated homocysteine has been reported as a risk factor for young adult central retinal vein occlusion (CRVO) cases. This study aimed to see if oxidative stress is an independent risk factor or is homocysteine dependent. METHODS: 23 young adult CRVO patients and 54 age and sex-matched controls were included in the study. Oxidative stress markers thiobarbituric acid-reacting substance (TBARS), superoxide dismutase (SOD), total thiols, glutathione peroxidase and total antioxidant capacity (TAC) were estimated. The effect of homocysteine (25-200 µM) on cultured bovine retinal endothelial cells (BREC) on oxidative stress parameter TBARS was measured. RESULTS: There was a significant increase in the plasma TBARS in CRVO cases compared with controls (p=0.000). SOD and TAC were significantly lower in CRVO cases than controls (p=0.000, p=0.022). There was a significant negative correlation between TAC and TBARS (p=0.00) and a significant positive correlation between homocysteine and TBARS (p=0.029). Nominal regression analysis showed that TAC and homocysteine influence TBARS significantly. The in-vitro study in BREC cells revealed that homocysteine increased the TBARS dose and time dependently. CONCLUSION: TBARS and homocysteine are known to be independent risk factors for CRVO. TBARS can be influenced by both homocysteine and TAC, thereby contributing to the aetiopathology of CRVO by increasing oxidative stress.
