Protective effects and its mechanism of lipoxins on human umbilical vein endothelial cells under hypoxia / 中华妇产科杂志

ABSTRACT

Objective To investigate protective effects and mechanisms of lipoxinA4(LXA4)on human umbilical vein endothelial cells(HUVEC)under hypoxia in vitro.Methods The HUVEC culture were divided into groups as followedadded M199 cudture medium as normal contml groups,added CoCl2 to mimic hypoxia in vitro as hypoxia group and added different concentrations of LXA4(1,10,100 nmol/L)were added to the induced hypoxiai HUVEC as agents intervention group.Morphological changes of HUVEC were observed by using inverted phase contrast mieroscope.The influence of LXA4 on cell survival was investigated by methyl thiazolyl tetrazolium(MTT) assaying method after the treatment with different concentrations of LXA4 and 100 nmol/L lipoxinA4 according to different time(4,8,12 and 24 hours).The expression of von-willebrand factor (vWF) was detected by immunocytoehemistry method. The changes of cytosolic Ca2+ were measured by laser scanning confocal microscope. Results ( 1 ) Morphological changesthe cells under hypoxia lost its normal shapes and showed necrosis, while the cells cocuhured with 100 nmol/L LXA4 were normal appropriately. (2)Survival rate the survival rates of HUVEC under hypoxia was (40. 1±3.9) % and increased to ( 52. 9 ± 1.4) %, (64. 1 ± 3. 3 ) %, ( 76. 6 ± 1.6) % respectively when added with LXA4 with concentration of 1,10, 100 nmol/L into culture medium. There was significant different survival rate when compared with that of hypoxia group. (3) The level of vWF The expression of vWF was decreased with the increasing concentrations of LXA4 added into culture medium, the gray values were 203.9 ±0. 7 in 1 nmol/L,204.6 ±0. 9 in 10 nmoL/L,191.8 ±0. 5 in 100 nmol/L respectively, which reached statistical difference in comparison with that of hypoxia groups (P<0. 05). (4) Confocai analysis:the intracellular free Ca2+ concentrations of HUVEC were intensified with LXA4 treatment. Conclusions LXA4 plays an important role in keeping the normal shape of HUVEC under hypoxia, can enhance survival of hypoxial HUVEC and decrease the level of vWF in cytoplasm. The protective mechanism might be via decreasing mitochondria Ca2+ overload and increasing cytoplasm Ca3+ by nucleus Ca2+ transference.