Protective Effect Of Polysaccharide L01 On Human Umbilical Vein Endothelial Cell From Suffered LPS

Objective:To study the effect of Polysaccharide L01 from Laminaria on the expression and secretion of inducible nitric oxide synthase(iNOS),endothelial nitric oxide synthase(eNOS),prostaglandin I₂(prostacyclin)(PGI₂)stimulated by Lipopolysaccharide in cultured human umbilical vein endothelial cell (HUVEC),thus providing an experimental basis for developing a new drug for antithrombosisMethods:(1)The human umbilical vein endothelial cell was divided into 7 group randomly as blank control group,L01 control group,LMWH control group,model group.L-L01 treatment group,H-L01 treatment group,LMWH treatment group.With 40mg/L Lipopolysaccharide added,human umbilical vein endothelial cell was exposed to LMWH and different concentration of Polysacchatide of Laminaria(L01)and cultured for 48 hours.The level of iNOS, eNOS and 6-Keto-PGF1αin cultured supernatants was measured by enzyme-linked immunosorbent assay(ELISA).(2)Reverse transcriptase chain reaction(RT-PCR)was used to detect the expression of iNOS,eNOS and PGIS messenger RNA(mRNA)in HUVEC in all groups and the related products were examined by densityscan and half-quantiative analysis after electrophoresis to reflect the variety of the transcription level.(3)The ultrastructure of samples was observed by transmission electron microscope. Result:(1)Stimulated by 40mg/L LPS for 48h,the level of eNOS and 6-Keto-PGF1αdecreased significantly(P＜0.01,P＜0.05)and iNOS increased significantly(P＜0.01,P＜0.05)in cultured supernants.Besides the expression of eNOSrnRNA and PGISmRNA were down-regulated and iNOSmRNA was up-regulated in the HUVEC.After observed by transmission electron microscope,we found that the irregularity cellular nucleus,microvilli decreased and disaapeared,engorgement of mitochondrium,cristae dissolved and disaapeared,cytolysosome increased.But the effect of LPS was reduced by HMWH and different concentration of polysaccharide L01 from Laminaria after cultured.Conclusion:L01 not only enhanced the LPS-stimulated secretion of eNOS and 6-Keto-PGF1α,reduced the secretion of iNOS in cultured supernants,but also increased the LPS-stimulated expression of eNOSmRNA and PGISmRNA, decreased the expression of iNOSmRNA in the HUVEC,so increase the ratio of eNOS/β-actine,PGIS/β-actine,decrease the ratio of iNOS/β-actine.Except that,L01 also reduce the injury of HUVEC in ultrastructure.So Polysaccharide L01 from Laminaria can protect HUVEC in function and morphology.