AIM: To study the changes of iNOS mRNA ,protein and the production of nitric oxide(NO) as well as whether puerarin regulates the expression of iNOS mRNA during the formation of diabetic rat cataract. METHODS: One hundred and eight Sprague-Dawley(SD) rats were randomly divided into three groups, thirty-six rats were taken as control group, seventy two rats were injected peritoneally with streptozotocin(STZ,45mg/kg) to establish animal model of diabetic cataract, and then divided into STZ (36) and puerarin(36) treatment groups. Morphologic changes of lens were observered with slit lamp and light microscope; Samples were taken at 20th, 40th, 60th day and the changes in iNOS mRNA and protein expression of lens epithelium cells(LEC)as well as production of NO and NOS activity were determined with reverse transcription -polymerase chain reaction(RT-PCR), western blot, and biochemical method ,respectively. RESULTS: Morphologyic changes of LEC, up-regulation of iNOS mRNA and iNOS protein as well as increase in NO production and NOS activity in the LEC were observered during the formation of rat diabetic cataract. Compared with TZ group, puerarin treatment group showed distinctly down-regulation of iNOS mRNA and iNOS protein and decrease in NO production and NOS activity as well as attenuation of morphologic changes. CONCLUSIONS: There are morphologic changes of LEC and up-regulation of iNOS mRNA and as well as increase in NO production and NOS activity in the LEC during the formation of diabetic rat cataract , and treatment with puerarin can reverse the above changes.

Objective To study the mechanism of p55 inducing cell apoptosis, the 180 bp fragment of Puma promoter was cloned into the pGL3-basic luciferase reporter vector. The biological activity of Pumareporter plasmid was verified by cell transfection. Methods The target fragments of Puma were amplified by RT-PCR method and the fragments were inserted into the pGL3-basic luciferase reporter vector. The acquired Puma-Luc plasmid was transfected into H1299 cell line and detected its activity. Results Sequencing indicated that the amplified Puma promoter is correct. Dual-luciferase Reporter Assay showed the Puma-Luc constructs have promoter activity. Conclusion The cloning of human Puma gene promoter and the construction of its reporter vector were successful. This study will lay the foundation for further research on the function of p53 inducing apoptosis through mitochondrial pathway.