Biological Association and Expressions of NOS3 & SOD2 in Non-Diabetic Senile Cataractogenesis

Aim: To evaluate the functional relationship between the nitric oxide synthase (NOS) and superoxide dismutase (SOD) enzymes in the pathogenesis of human senile cataract lenses of non-diabetic patients. Methods: Total solubilized proteins from human cataract lens were compared with normal lens (control) by 2-Dimenstional gel electrophoresis (2-DE). Proteins with different abundances were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Western blot analysis was used to verify the changes in expression of NOS3 and SOD2. A further functional association of NOS3 with SOD2 and other proteins was seen by STRING 8.3 databases. Results: In the 2-DE maps, the cataract and normal lens proteins migrated in the region of pH 3 - 10 with a relative molecular weight of 20 - 130 kDa. Approximately two protein spots with differential intensity were detected as NOS3 and SOD2 using MALDI-TOF-MS. Western blot analysis showed high expression of NOS3 in cataract and SOD2 in normal lens samples. String interaction network revealed strong interactions between NOS3 and SOD2 at high confidence score, which is helpful in characterization of functional abnormalities that may be a causative factor in the pathogenesis of cataract. Conclusion: This study will offer new avenues for mechanistic evaluation and future prevention of cataractogensis. However, large scale studies will be required to evaluate the effect of this interaction on the clinical outcome in human cataract.