Overexpression of acetylcholinesterase inhibited cell proliferation and promoted apoptosis in NRK cells

AIM: To study the potential function of acetylcholinesterase (AChE) in apoptosis through overexpression of AChE in Normal Rat Kidney (NRK) cells. METHODS: AChE activity was detected by the method of Karnovsky and Roots. Activated caspase-3 was analyzed by Western blotting and immunoflurescence with antibody special to activated caspase-3 fragment. The expression plasmids were constructed in pcDNA3.1 containing AChE gene or a fragment of AChE antisense that were got from RT-PCR. Stable expression cell lines were selected by G418 in cells transfected by lipofection. AChE expression was analyzed by RT-PCR and Western blotting. The proliferation rates of transfected cells were examined by the growth curve and cloning efficiency. MTT assay was used to analyze the cell viability. RESULTS: The proliferation rate of the cells transfected with AChE was retarded and the cloning efficiency was lower (28.2%±3.1% and 48.7%±2.1%) than cells transfected with vector (56.1%±0.3 %) or AChE-antisense (77.7%±2.2%). After 2 d the various clone types were deprived of serum, the residue cell viability were 10.4%±4.6% and 12.6%±6.7% in the cells transfected with AChE, and 27.4%±3.5% in cells with vector, and 50.3%±7.8% in cells with AChE-antisense. CONCLUSION: During apoptosis, increase of AChE protein is to inhibit cell proliferation, and then to promote apoptosis in NRK cells.