10.22376/ijpbs.2019.10.1.p1-12 Volume 8 Issue 4 2017 (October - December) Nitrosative stress leads to Parkinson's disease through mitochondrial dysregulation. Although Parkinson's disease is caused by several genes such as lessThan i greaterThan Parkin lessThan /i greaterThan lessThan i greaterThan , DJ-1, PINK1, ATP13A2, PLA2G6, FBXO7, SNCA, LRRK2, VPS35 lessThan /i greaterThan and lessThan i greaterThan GBA lessThan /i greaterThan but there is a need for the investigation of sensitivity and expression of Parkinson's disease genes upon nitrosative stress. Hence the current study focused on Parkinson's disease gene expression in PC12 cells upon nitrosative stress. The nitrosative stress was carried out by rotenone, SIN1 and peroxynitrite and the expression pattern of genes were studied using real time PCR. PTEN-Induced putative kinase 1 ( lessThan i greaterThan PINK1 lessThan /i greaterThan ), Leucine-rich repeat kinase 2 ( lessThan i greaterThan LRRK2 lessThan /i greaterThan ) and Vacuolar Protein Sorting-associated protein 35 ( lessThan i greaterThan VPS35 lessThan /i greaterThan ) genes were analysed by real time PCR. Our findings demonstrate that under nitrosative stress the expression of lessThan i greaterThan VPS35 lessThan /i greaterThan is up regulated by 1.35 fold when treated with lower concentration of peroxynitrite (250 µM); however under higher concentration it is down regulated :10 fold with 1mM peroxynitrite, 16.7 fold with 0.5 µM and 2.5 µM rotenone, 8.3 fold and 7.6 fold with 50 µM and 250 µM SIN1. The lessThan i greaterThan PINK1 lessThan /i greaterThan found to be down regulated: 50 fold with 250 µM peroxynitrite, 20 fold with 1mM peroxynitrite, 14.3 fold with 0.5 µM rotenone, 16.7 fold with 2.5 µM rotenone, 11.1 fold with 50 µM SIN1 and 10 fold with 250 µM SIN1 under all concentrations; surprisingly lessThan i greaterThan LRRK2 lessThan /i greaterThan gene did not show any kind of expression during PCR optimisation itself. In conclusion lessThan i greaterThan PINK1 lessThan /i greaterThan appears to be most sensitive compare to lessThan i greaterThan VPS35 lessThan /i greaterThan as it is down regulated with lower concentration of peroxynitrite. ANUSHREE , ARAVIND P, GIRISHA SHRINGALA THIMAPPA AND DEVARAJU KURAMKOTE SHIVANNA Gene expression, Nitrosative stress, Parkinson’s disease, Real Time PCR 49-56