DSCR1 gene silencing by siRNA in fibroblast cells from patient with down syndrome

Abstract

DSCR1 (Down Syndrome Critical Region 1) is overexpressed in fetal Down Syndrome (DS) brain. DSCR1 belongs to highly conserved calcineurin inhibitor family called calcipressin. DSCR1 can bind to and inhibit calcineurn, a protein important for learning and memory. Small interfering RNA (siRNA) molecules are the key intermediaries in post-transcriptional gene silencing which when exogenously administered can inhibit the expression of any given target gene. Since DSCR1 is overexpressed in DS fetal brain, it’s possible that normalizing DSCR1 ecpression may restore normal brain function is DS individual. The goal of this study is to inhibit DSCR1 gene in fibroblast cells by siRNA. The comparison result of mRNA (by real time PCR) and protein (by western blot) gene expression between untreated and treated with 3 concentrations of siRNAs in control and case samples indicated that siRNAs did not affect to mRNA level of DSCR1 gene in control samples (t test, Pr=0.61, 0.5626 and 0.3947) due to the long period of post-transfection. The RFP (Red Florescent Protein) gene was cloned into siRNA plasmid vector to indicate the uptake rate and siRNA efficiency. RFP signal was shown that siRNAs were effectively within 5 days of post-transfection but the limitation of cell lines growth could not collect cell within 5 days. The Result of siRNA effect in case samples indicated that siRNA concentration 0.5fold and 1 fold increased DSCR1 mRNA level (t test, Pr=0.0203 and 0.0054). By the way, the result of 1.5 fold of siRNAs in case samples indicated that siRNAs at high concentration could not affect to mRNA