Lipids最新文献

Seed oils sourced from West Africa are generally not well-characterized, but likely to have an untapped potential. This review aims to make an overview of fatty acid (FA) composition of unconventional seed oils from semi-arid West African trees and evaluate potential for new and enhanced uses and for improving local livelihoods and biodiversity conservation. A total of 111 studies on FA composition were found, covering 31 species. Only 69 of the studies (62%) were included in the review, as 38% had unreliable or incomplete results. There was a clear link between taxonomic kinship and FA composition. Over 20 potentially interesting and underexploited oils were found, including oils with properties similar to palm oil, olive oil, coconut oil, shea butter, and cotton seed oil. About half of the oils have promising potential for cosmetics. One third of the oils were relatively saturated, indicating properties for structuring food and heat resistance. Most of the species had multiple uses and oil production could be profitable in co-production with other non-timber forest products. Furthermore, establishment of sustainable oil production and domestication of oil trees could promote biodiversity conservation. Enhanced oil production in semi-arid West Africa is promising, but several practical constraints remain to be overcome.

Implementing insects, such as the black soldier fly larvae (BSFL), as animal feed commonly includes the previous removal of substantial amounts of fat. This fat may represent an as yet underutilized energy source for livestock. However, transfer of lauric and myristic acid, prevalent in BSFL fat and undesired in human nutrition, into animal-source foods like eggs may limit its implementation. To quantify this, a laying hen experiment was performed comprising five different diets (10 hens/diet). These were a control diet with soybean oil and meal and a second diet with soybean oil but with partially defatted BSFL meal as protein source. The other three diets were based on different combinations of partially defatted BSFL meal and fat obtained by two different production methods. Lauric acid made up half of the BSFL fat from both origins. Both BSFL fats also contained substantial amounts of myristic and palmitic acid. However, in the insect-based diets, the net transfer from diet to egg yolk was less than 1% for lauric acid, whereas the net transfer for myristic and palmitic acid was about 30% and 100%, respectively. The net transfer did not vary between BSFL originating from production on different larval feeding substrates. The results illustrate that hens are able to metabolize or elongate very large proportions of ingested lauric acid and myristic acid, which are predominant in the BSFL lipids (together accounting for as much as 37 mol%), such that they collectively account for less than 3.5 mol% of egg yolk fatty acids.

High serum levels of triglycerides (Tg) and low levels of high-density lipoprotein cholesterol (HDL-C) are characteristic of the Metabolic Syndrome (MetS). We assessed the ratio of Tg to HDL-C as a way to identify MetS and insulin resistance. We also evaluated its association with severity of carotid atherosclerosis. Data were analyzed from three cohorts totaling 13,908 participants. MetS was defined according to the International Diabetes Federation criteria. Optimal cut-off for Tg/HDL-C ratio was obtained using Youden's index in receiver-operating characteristic (ROC) curve analyses. The risk of MetS and IR in those with a Tg/HDL-C ratio above the optimum cutoff was evaluated by logistic regression analysis. A Tg/HDL-C ratio above the optimal cutoff level significantly increased the odds ratio for MetS in the three cohorts (OR 6.00, 4.04, and 3.50, least in the healthy population), identified insulin resistance defined by the homeostatic model of insulin resistance (HOMA-IR) (p < 0.0001), and was strongly associated with atherosclerosis severity (p = 0.0001). Tg/HDL-C ratio identifies persons with MetS, insulin resistance, and severe atherosclerosis. It should be used more widely to identify patients at high risk. This is clinically important because insulin resistance is treatable.

Cholesterol metabolism is paramount to cells. Aberrations to cholesterol metabolism affects cholesterol homeostasis, which may impact the risk of several diseases. Recent evidence has suggested that vascular smooth muscle cell (VSMC) cholesterol metabolism may play a role in atherosclerosis. However, there is scant in vitro mechanistic data involving primary VSMC that directly tests how VSMC cholesterol metabolism may impact atherosclerosis. One reason for this lack of data is due to the impracticality of gene manipulation studies in primary VSMC, as cultured primary VSMC become senescent and lose their morphology rapidly. However, there are no immortalized VSMC lines known to be suitable for studying VSMC cholesterol metabolism. The purpose of this study was to determine whether MOVAS cells, a commercially available VSMC line, are suitable to use for studying VSMC cholesterol metabolism. Using immunoblotting and immunofluorescence, we showed that MOVAS cells express ABCA1, ABCG1, and SREBP-2. We also determined that MOVAS cells efflux cholesterol to apoAI and HDL, which indicates functionality of ABCA1/ABCG1. In serum-starved MOVAS cells, SREBP-2 target gene expression was increased, confirming SREBP-2 functionality. We detected miR-33a expression in MOVAS cells and determined this microRNA can silence ABCA1 and ABCG1 via identifying conserved miR-33a binding sites within ABCA1/ABCG1 3′UTR in MOVAS cells. We showed that cholesterol-loading MOVAS cells results in this cell line to transdifferentiate into a macrophage-like cell, which also occurs when VSMC accumulate cholesterol. Our characterization of MOVAS cells sufficiently demonstrates that they are suitable to use for studying VSMC cholesterol metabolism in the context of atherosclerosis.

MicroRNA-328 (miR-328) was reported to protect against atherosclerosis, but its role in foam cell formation remains unknown. The aim of this study was to investigate the effect of miR-328-5p on macrophage lipid accumulation and the underlying mechanisms. The results showed that miR-328-5p expression was robustly decreased in oxidized low-density lipoprotein (ox-LDL)-treated macrophages. Treatment of human acute monocytic leukemia cel (THP-1) macrophage-derived foam cells with a miR-328-5p mimic markedly increased [³H]-cholesterol efflux, inhibited lipid droplet accumulation, and decreased intracellular total cholesterol (TC), free cholesterol (FC) and cholesteryl ester (CE) contents. Upregulation of miR-328-5p also reduced the expression of histone deacetylase 3 (HDAC3) but increased the levels of ATP-binding cassette transporter A1 (ABCA1) in THP-1 macrophage-derived foam cells. Mechanistically, miR-328-5p inhibited HDAC3 expression by directly targeting its 3′UTR, thereby promoting ABCA1 expression and the subsequent cholesterol efflux. Furthermore, miR-328-5p mimic treatment did not affect the uptake of Dil-ox-LDL or the expression of scavenger receptor-A (SR-A), thrombospondin receptor (CD36) and ABCG1. Taken together, these findings suggest that miR-328-5p alleviates macrophage lipid accumulation through the HDAC3/ABCA1 pathway.

Diacylglycerol kinase (DGK) phosphorylates diacylglycerol to produce phosphatidic acid (PtdOH) and regulates the balance between two lipid second messengers: diacylglycerol and PtdOH. Several lines of evidence suggest that the η isozyme of DGK is involved in the pathogenesis of bipolar disorder. However, the detailed molecular mechanisms regulating the pathophysiological functions remain unclear. One reason is that it is difficult to detect the cellular activity of DGKη. To overcome this difficulty, we utilized protein myristoylation and a cellular PtdOH sensor, the N-terminal region of α-synuclein (α-Syn-N). Although DGKη expressed in COS-7 cells was broadly distributed in the cytoplasm, myristoylated (Myr)-AcGFP-DGKη and Myr-AcGFP-DGKη-KD (inactive (kinase-dead) mutant) were substantially localized in the plasma membrane. Moreover, DsRed monomer-α-Syn-N significantly colocalized with Myr-AcGFP-DGKη but not Myr-AcGFP-DGKη-KD at the plasma membrane. When COS-7 cells were osmotically shocked, all DGKη constructs were exclusively translocated to osmotic shock-responsive granules (OSRG). DsRed monomer-α-Syn-N markedly colocalized with only Myr-AcGFP-DGKη at OSRG and exhibited a higher signal/background ratio (3.4) than Myr-AcGFP-DGKη at the plasma membrane in unstimulated COS-7 cells (2.5), indicating that α-Syn-N more effectively detects Myr-AcGFP-DGKη activity in OSRG. Therefore, these results demonstrated that the combination of myristoylation and the PtdOH sensor effectively detects DGKη activity in cells and that this method is convenient to examine the molecular functions of DGKη. Moreover, this method will be useful for the development of drugs targeting DGKη. Furthermore, the combination of myristoylation (intensive accumulation in membranes) and α-Syn-N can be applicable to assays for various cytosolic PtdOH-generating enzymes.

Statins are commonly prescribed antilipidemic and anticholesterol class of drugs. In addition to their major role, they have been found to have anticancer effects on in vitro, animal and clinical studies. The aim of this study was to investigate the effects of six different statins (rosuvastatin, pravastatin, simvastatin, lovastatin, fluvastatin, and atorvastatin) on A549 cancer cells lipids by Fourier transform infrared (FTIR) spectroscopy. Proliferation tests were carried out to detect the half-maximal inhibitory concentrations (IC₅₀) of each statin on A549 cells. The IC₅₀ values were 50 μM for simvastatin, 150 μM for atorvastatin and pravastatin, and 170 μM for fluvastatin, 200 μM for rosuvastatin and lovastatin on A549 cells. No correlation was found between the antiproliferative effects of the statins and lipid-lowering effect. The cells were treated with IC₅, IC₁₀, and IC₅₀ values of each statins concentration and lipid extracts were compared using FTIR spectroscopy. The results indicated that different statins had different effects on the lipid content of A549 cells. The FTIR spectra of the lipid exctracts of statin-treated A549 cells indicated that the value of hydrocarbon chain length, unsaturation index, oxidative stress level, and phospholipid containing lipids increased except for rosuvastatin-treated A549 cells. In addition, rosuvastatin significantly lowered cholesterol ester levels. In conclusion, the contrasting effects of rosuvastatin should be further investigated.

In the present study, the lipid amount and fatty acid profile of different Sparidae species, including gilthead seabream, juvenile gilthead seabream, annular seabream, white seabream, common two-banded seabream were evaluated. Fish were seasonally collected from Köyceğiz Lagoon (Muğla, South Western Turkey) from June 2018 to June 2019 and after collection, the sex of each specimen was recorded. According to the results of the study, the highest lipid amount was found in female annular seabream individuals as 8.09 ± 0.78% in November and the lowest lipid amount was found in male juvenile gilthead seabream as 0.98 ± 0.12% in March. Palmitic acid and oleic acid were determined as the most abundant SFA and MUFA for all species, respectively. The highest value of DHA, which was the predominant PUFA was assessed as 15.33 ± 0.26% in female white seabream in November whereas the lowest value (3.83 ± 0.36%) was found in gilthead seabream in December. The n-6/n-3 ratio was determined between 0.27 ± 0.00 (for male common two-banded seabream in July)-1.20 ± 0.03 (for male gilthead seabream in December) and it followed within the range of healthy values for all species. As a conclusion, it was found that values of lipid and fatty acid profiles among the examined Sparidae species vary among the season of collection. The results of the study gave the seasonal nutritional values of four economically-important Sparidae species that being rich in healthy polyunsaturated fatty acids such as DHA, have beneficial in human nutrition.

Partially hydrogenated oils (PHO) have been removed from the food supply due to adverse effects on risk for coronary heart disease (CHD). High-oleic soybean oils (HOSBO) are alternatives that provide functionality for different food applications. The objective of this study was to determine how consumption of diets containing HOSBO compared to other alternative oils, with similar functional properties, modifies LDL cholesterol (LDLc) and other risk factors and biomarkers of CHD. A triple-blind, crossover, randomized controlled trial was conducted in humans (n = 60) with four highly-controlled diets containing (1) HOSBO, (2) 80:20 blend of HOSBO and fully hydrogenated soybean oil (HOSBO+FHSBO), (3) soybean oil (SBO), and (4) 50:50 blend of palm oil and palm kernel oil (PO + PKO). Before and after 29 days of feeding, lipids/lipoproteins, blood pressure, body composition, and markers of inflammation, oxidation, and hemostasis were measured. LDLc, apolipoprotein B (apoB), NonHDL-cholesterol (HDLc), ratios of total cholesterol (TC)-to-HDLc and LDLc-to-HDL cholesterol, and LDL particle number and small LDL particles concentration were lower after HOSBO and HOSBO+FHSBO compared to PO (specific comparisons p < 0.05). Other than TC:HDL, there were no differences in lipid/lipoprotein markers when comparing HOSBO+FHSBO with HOSBO. LDLc and apoB were higher after HOSBO compared to SBO (p < 0.05). PO + PKO increased HDLc (p < 0.001) and apolipoprotein AI (p < 0.03) compared to HOSBO and HOSBO+FHSBO. With the exception of lipid hydroperoxides, dietary treatments did not affect other CHD markers. HOSBO, and blends thereof, is a PHO replacement that results in more favorable lipid/lipoprotein profiles compared to PO + PKO (an alternative fat with similar functional properties).

ACYL-LIPID THIOESTERASES (ALT) are a type of plant acyl–acyl carrier protein thioesterase that generate a wide range of medium-chain fatty acids and methylketone (MK) precursors when expressed heterologously in Escherichia coli. While this makes ALT-type thioesterases attractive as metabolic engineering targets to increase production of high-value medium-chain fatty acids and MKs in plant systems, the behavior of ALT enzymes in planta was not well understood before this study. To profile the substrate specificities of ALT-type thioesterases in different plant tissue types, AtALT1-4 from Arabidopsis thaliana, which have widely varied chain length and oxidation state preferences in E. coli, were overexpressed in Arabidopsis seeds, Camelina sativa seeds, and Nicotiana benthamiana leaves. Seed-specific overexpression of ALT enzymes led to medium-chain fatty acid accumulation in Arabidopsis and Camelina seed triacylglycerols, and transient overexpression in N. benthamiana demonstrated that the substrate preferences of ALT-type thioesterases in planta generally agree with those previously determined in E. coli. AtALT1 and AtALT4 overexpression in leaves and seeds resulted in the accumulation of 12–14 carbon-length fatty acids and 6–8 carbon-length fatty acids, respectively. While it was difficult to completely profile the products of ALT-type thioesterases that generate MK precursors (i.e. β-keto fatty acids), our results nonetheless demonstrate that ALT enzymes are catalytically diverse in planta. The knowledge gained from this study is a significant step towards being able to use ALT-type thioesterases as metabolic engineering tools to modify the fatty acid profiles of oilseed crops, other plants, and microorganisms.