OBJECTIVETo investigate regulatory effect of Acheron (Achn) on proliferation and apoptosis of human vascular endothelial cell.

METHODS(1) Eahy926 cells were cultured in serum-free DMEM medium (96-well plates) and were divided into Achn inhibition group (transfected with plasmid psi-Achn), psi4.1 group (transfected with psi4.1 empty vector), Achn induction group (transfected with pcDNA-Achn), pcDNA3.1 group (transfected with pcDNA3.1 empty vector), cotransfection group [cotransfected with pcDNA-Achn + psi-calcium/calmodulin-dependent serine protein kinase (CASK)], blank control group (treated with PBS) according to the random number table (the same method below). The cell proliferation was determined by MTT assay at post transfection hour (PTH) 1, 24, 48, 72, with expression of absorbance value. (2) Total protein of Eahy926 cells were extracted and quantitated by BCA assay, and then they were divided into Achn antibody precipitation group (100 µg protein), CASK antibody precipitation group (100 µg protein), IgG antibody group (100 µg protein), Western blot group (20 µg protein). Achn and CASK protein levels were determined by immunoprecipitation and Western blot. (3) Synchronously cultured Eahy926 cells were divided into LPS induction group (treated with 5 mol/L LPS), Achn transfection group (transfected with pcDNA-Achn), cotransfection group (cotransfected with psi-CASK and pcDNA-Achn), KCl group (treated with 5 mol/L KCl), and blank control group (treated with 5 mol/L PBS). Cells in transfection groups were stimulated by LPS for 12 hours after PTH 24. Caspase-3 protein level was detected by immunohistochemistry. (4) Synchronously cultured Eahy926 cells were divided into Achn inhibition group (transfected with psi-Achn vector), Achn induction group (transfected with pcDNA-Achn vector), and blank control group (treated with PBS). Apoptosis rate was determined by FITC/PI with flow cytometry. Data were processed with one-way analysis of variance and t test.

RESULTS(1) The cell proliferation in Achn inhibition group was lower than that in psi4.1 group from PTH 24, and the differences were statistically significant at PTH 48, 72 (with t value respectively 10.777, 6.112, P values all below 0.05). The cell proliferation in Achn induction group during PTH 24-72 were higher that in pcDNA3.1 group (with t value respectively 5.367, 6.053, 9.831, P values all below 0.05). The cell proliferation in cotransfection group at PTH 48, 72 were significantly lower than that in Achn induction group (with t value respectively 5.481, 9.517, P values all below 0.05). (2) Achn protein was detected in CASK antibody precipitation group while CASK protein was also detected in Achn antibody precipitation group. (3) Caspase-3 level in Achn transfection group was lower [(15.6 ± 0.5)%] as compared with that in LPS induction group [(32.8 ± 2.6)%, t = 10.083, P < 0.05], and that in cotransfection group showed further inhibition [(7.0 ± 2.0)%, t = 9.827, P < 0.01]. (4) Apoptosis rate in Achn inhibition group [(45.6 ± 10.9)%] was higher than that in blank control group [(13.2 ± 4.3) %, t = 7.043, P < 0.05]; while that in Achn induction group [(5.3 ± 2.9)%] was lower than that in blank control group (t = 6.499, P < 0.05).

CONCLUSIONSAchn can promote human vascular endothelial cell proliferation, and inhibit its apoptosis induced by LPS or burn serum, and the effect is related to CASK.