Lipid rafts and Fas/FasL pathway may involve in elaidic acid-induced apoptosis of human umbilical vein endothelial cells

Egg White-Derived Peptides QVPLW and LCAY Inhibit the Activity of Angiotensin I-Converting Enzyme in Human Umbilical Vein Endothelial Cells by Suppressing Its Recruitment into Lipid Rafts

As a membrane protein, the activity of angiotensin I-converting enzyme (ACE) can be modulated via regulation of its localization in the cell membrane with food-derived peptides. This study aimed to explore the effect of egg white peptides on the cell membrane localization and activity of ACE in human umbilical vein endothelial cells. ACE activity was found to be related to lipid rafts by using methyl-β-cyclodextrin (MβCD). QVPLW and LCAY can inhibit ACE activity by preventing ACE recruitment into lipid rafts, with in situ IC₅₀ values of 238.46 ± 11.35 μM and 31.55 ± 2.64 μM in the control groups, as well as 45.43 ± 6.15 μM and 34.63 ± 1.59 μM in the MβCD groups, respectively. QVPLW and LCAY may alter the cell membrane properties, including the fluidity, potential, and permeability, and eventually promote the transposition of ACE.

9t18:1 and 11t18:1 activate the MAPK pathway to regulate the expression of PLA2 and cause inflammation in HUVECs

trans fatty acids (TFAs) have been reported to promote vascular diseases mainly by promoting apoptosis and inflammation of vascular endothelial cells. However, it has been reported in recent years that elaidic acid (9t18:1) and vaccenic acid (11t18:1) may have different effects on vascular health. This study investigated the effects of 9t18:1 and 11t18:1 on human umbilical vein endothelial cell (HUVEC) function and the possible mechanism of inflammation by analyzing the changes in the phospholipid composition and the relationship between phospholipase A2 (PLA2) and MAPK pathway. Here we found that the effect of 11t18:1 on cell viability, membrane damage and cellular inflammation was significantly lower than that of 9t18:1 (p < 0.05). And 9t18:1 and 11t18:1 had different effects on phospholipid composition. Both 9t18:1 and 11t18:1 significantly increased the protein expression of PLA2. Moreover, the MAPK pathway regulated the expression of PLA2, inflammatory cytokines and cyclooxygenase-2 (COX-2) and the secretion of prostaglandin E2 (PGE2) in HUVECs induced by 9t18:1 and 11t18:1. In conclusion, 9t18:1 and 11t18:1 activated the MAPK pathway which regulated the expression of PLA2 to cause inflammation in HUVECs.

Association between KIF1B (rs17401966) polymorphism and hepatocellular carcinoma susceptibility: a meta-analysis

Introduction

The results of the earlier published studies on the association between KIF1B (rs17401966) polymorphism and hepatocellular carcinoma (HCC) risk are inconclusive. Hence, we performed this meta-analysis to evaluate the relationship between KIF1B (rs17401966) polymorphism and HCC risk.

Methods

Databases including PubMed, Web of Science and the Cochrane Library and bibliographies of relevant papers were screened to identify relevant studies published up to March 25, 2018. Pooled ORs and 95% CIs were calculated to evaluate the association. The subgroup analysis was conducted based on ethnicity, age, region and environment. A total of 19 studies from 11 eligible articles published from 2010 to 2016, with 8,741 cases and 10,812 controls, were included.

Results

The pooled results indicated that the association between KIF1B (rs17401966) polymorphism and the decreased HCC risk was significant. Subgroup analysis stratified by ethnicity showed the same association in Chinese, but not in non-Chinese population. When stratified by age, both old and young patients showed a decrease in HCC risk. When stratified by region, we detected the same association in Chinese in southern China. Similarly when stratified by environment, we observed the same association in Chinese in inland areas; however, no statistically significant association was observed in those in coastal areas.

Conclusion

This meta-analysis suggested that KIF1B (rs17401966) polymorphism could decrease HCC risk in Chinese and in overall population, but not in non-Chinese. This association remained significant in Chinese in southern China and inland areas, but not in those in northern and central China and coastal areas. Further large-scale multicenter studies are warranted to confirm these findings.

Biological effects of trans fatty acids and their possible roles in the lipid rafts in apoptosis regulation

A large number of recent studies are focused on evaluating the mechanism of action of trans fatty acids (TFAs) on the progression of apoptosis. A strong positive association has been reported between TFA and coronary heart disease (CHD), obesity and nonalcoholic steatohepatitis and so on. The present study reviewed the biological effects of trans fatty acids (TFA) and their possible roles in lipid rafts in regulating apoptosis. The following aspects of TFA were included: the research about TFA and diseases affecting serum lipid levels, inducing system inflammation and immune response, and the correlation between TFA and apoptosis. The primary purpose of the review article was to comprehensively evaluate the potential correlation between lipid rafts and apoptosis induced by different structures of TFA and provide some new research progress and future directions about it.

Pro-metastatic signaling of the trans fatty acid elaidic acid is associated with lipid rafts

Trans fatty acids (TFAs) are risk factors for cardiovascular disorders, and the cancer-promoting effects of TFAs have been previously reported. The present study examined the effects and signaling of elaidic acid (EA), a TFA, in colorectal cancer (CRC) cells. Oral intake of EA was found to increase metastasis of HT29 human CRC cells. Results indicated that, in the plasma membrane, EA was integrated into cholesterol rafts, which contain epidermal growth factor receptors (EGFR). EA increased nanog and c-myc, and decreased PGC-1A through lipid raft-associated EGFR signaling in HT29 cells. Depletion of cholesterol by methyl-β-cyclodextrin treatment abrogated the EA-induced stemness and oxidative phosphorylation. Simvastatin treatment also abrogated EA-enhanced tumor growth. These results indicate that EA enhances the stemness by activating EGFR in lipid rafts.

Potential Pathways Involved in Elaidic Acid Induced Atherosclerosis in Human Umbilical Vein Endothelial Cells

Researches have demonstrated that trans-fatty acids are related to the progression of atherosclerosis, but the underlying mechanism is not clear till now. In the presented study, two-dimensional electrophoresis based proteomics was used to discover the role of elaidic acid in atherosclerosis. In human umbilical vein endothelial cells (HUVEC), twenty-two and twenty-three differentially expressed proteins were identified in low (50 μmol/L) and high (400 μmol/L) concentration elaidic acid simulated groups, respectively, comparing with the control group. The expressions of some selected proteins (PSME3, XRCC5, GSTP1, and GSTO1) were validated by qRT-PCR analysis. Western blotting analysis further confirmed that elaidic acid downregulated the expression of PSME3and XRCC5. Moreover, P53, the downstream protein of PSME3, was further investigated. Results demonstrated that a variety of proteins, many of which were related to oxidative stress, apoptosis, and DNA damage, were involved in the elaidic acid induced atherosclerosis. Furthermore, P53 was demonstrated to regulate the atherosclerosis through cell cycle arrest and apoptosis pathway.