| Epidemiological and clinical study showed that diet with rich industrial trans fatty acids could increase plasma lipids and cause AS and cardiovascular disease.Thus,many country carried out policy to limit the contents of trans fatty acids in food products.However,trans fatty acids also found in the lipids of ruminant animals meat and milk products with little contents.And there is currently no policy to restrict its use.Under the global environment of limiting trans fatty acids,it is necessary to understand the effects of trans fatty acids in ruminants on human health,especially on cardiovascular disease,which plays an important role to clarify the safety and guidance of ruminant animal foods.Phospholipids,as the basic component of biofilms,are widely involved in basic life activities such as substance and energy metabolism and information transmission.Phospholipid structure and metabolic abnormalities will lead to cell structure destruction and abnormal function,thereby damaging human health.Fatty acids could affect the composition of phospholipids on the cell membrane and the composition of phospholipids in the cell membrane could directly affect the function of cells and blood vessels.Thus,how do trans fatty acids in ruminants influence phospholipid profile of endothelial cells?whether they affect endothelial cell function by changing phospholipids structure and then affect affect vascular function or not.Therefore,this project determined the trans fatty acid isomer content in ruminant animals and hydrogenated soybean oil to identify the most important trans-fatty acids in ruminant lipids and hydrogenated oils;Human umbilical vein endothelial cells were treated with 11t18:1 and 9t18:1 and their cis-isomer 9c18:1 and 11c18:1 were used as control groups to observe the effects of trans-fatty acids on inflammatory reaction and cell membrane damage.Based on the phospholipidomics technology,the effect of trans fatty acids in ruminant animals on the phospholipid profile of endothelial cells was investigated.The differential phospholipid metabolites were identified by PCA and PLS-DA multivariate statistical analysis to speculate and verify the differential phospholipase,find phospholipids and phospholipase biomarkers,and to explore the link between phospholipase and MAPK-related pathways,to find out the effect of trans-fatty acid ester structure of ruminants on endothelial cell membrane phospholipids and its mechanism.1,Determination of trans-fatty acid isomers in ruminants and hydrogenated soybean oils by solid-phase extraction of silver ions combined with gas chromatography.The results showed that trans-l6:l,trans-18:1 and trans-18:2 were presented in ruminant animal lipids,while hydrogenated soybean oil contains trans-18:1 and trans-18:2,of which trans-18:1 is the richest trans fatty acid among ruminant animals lipids and hydrogenated soybean oil,in which the highest content of trans-fatty acid isomers in hydrogenated soybean oil is 9t18:1,and the highest content of transfatty acid isomers in ruminant lipids is 11t18:1.Therefore,9t18:1 and 11t18:1 are used for follow-up experiments of industrial trans-fatty acids and ruminant trans-fatty acids,respectively.2,The effects of industrial trans-fatty acids and ruminant trans fatty acids on the function and fatty acid metabolism of human umbilical vein endothelial cells were compared.The results showed that both 9t18:1 and 11t18:1 could inhibit cell proliferation in a concentration-dependent manner.9t18:1 and 11t18:1 could also increase the expression of intracellular inflammatory factors ICAM-1,VCAM-1 and IL-6,increase the permeability of the cell membrane,reduce the fluidity of the cell membrane,and change the integrity of the cells.Among them,cell damage induced by 9t18:1 was significantly higher than11t18:1.In addition,the absorption rate of 9t18:1 in cells was found to be higher than 11t18:1.After treated with 9t18:1 and 11t18:1,both trans fatty acids could transformed into 7t16:1 and 9t16:1 through β oxidation,respectively.Among them,11t18:1 had the highest conversion rate,reaching 22.17%.In addition,11t18:1 partially converted to 9c11t-CLA in endothelial cells with a conversion rate of 8.27%.This may be the reason for the difference in cell function between 9t18:1 and 11t18:1.3,The effect of trans fatty acids in ruminants on phospholipid organization in human umbilical vein endothelial cells was determined by shotgun-MS and LC-MS.The results showed that there were four kinds of phospholipids(PC,PE,PS,PI)and four lysophospholipids(LPC,LPE,LPS,LPI)in endothelial cells,among which PC and PE were the main phospholipids;After the cells,the phospholipid structure of the cell membrane changed significantly,PE and PS decreased significantly,while the content of PI and lysophospholipid increased significantly.The result of PCA showed that the effects of 11t18:1 and 9t18:1 were similar,and the results of 9c18:1 and 11c18:1 were similar.Similarly,cluster analysis showed that the effects of 9t18:1 and 11t18:1 were similar,and the results of 9c18:1 and 11c18:1 were similar.After PLS-DA analysis found that fatty acids act on the cell membrane,the biologically diverse phospholipids are mainly some phospholipids that bind SFA and PUFA.Components indicate that fatty acids will replace their binding sites and cause them to degrade.4,The effect of trans-fatty acid on the phospholipase of human umbilical vein endothelial cells was determined by western-blot and the relationship between phospholipase and MAPK was discussed.The results showed that 9t18:1 and 11t18:1 and their cis-isomer 9c18:1 and 11c18:1 both significantly increased the expression of intracellular c PLA2,p-c PLA2,s PLA2,and i PLA2,9t18:1 and 11t18: 1 significantly increased the expression of s PLA2 in cells,while 9c18:1 and 11c18:1 were more likely to significantly increase the expression of intracellular i PLA2.In addition,it was also found that the MAPK signaling pathway regulates phospholipase A2 regulation of trans fatty acid-induced intracellular inflammatory responses.When phospholipase inhibitors inhibit the expression of the corresponding phospholipase,the expression of inflammatory factors ICAM-1,VCAM-1,and IL-6,and COX-2 and PGE2 secretion were significantly down-regulated.When MAPK pathway was inhibited by the corresponding MAPK inhibitors.The expression of phospholipase A2 and inflammatory factors ICAM-1,VCAM-1,and IL-6,as well as COX-2 expression and PGE2 secretion were significantly down-regulated. |
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