-
American Journal of Physiology.... Jun 2024FATP4 was thought to mediate intestinal lipid absorption which was disputed by a study using keratinocyte-Fatp4-rescued Fatp4 mice. These knockouts when fed with a...
FATP4 was thought to mediate intestinal lipid absorption which was disputed by a study using keratinocyte-Fatp4-rescued Fatp4 mice. These knockouts when fed with a western diet showed elevated intestinal triglyceride (TG) and fatty-acid levels. To investigate a possible role of FATP4 on intestinal lipid processing, (KO) mice were generated by -specific inactivation of the Fatp4 gene. We aimed to measure circulating and intestinal lipids in control and KO mice after acute or chronic fat intake or during ageing. Remarkably, mice displayed a ~30% decrease in ileal behenic, lignoceric, and nervonic acids, ceramides containing these FA, as well as, ileal sphingomyelin, phosphatidylcholine, and phosphatidylinositol levels. Such decreases were concomitant with an increase in jejunal cholesterol ester. After 2-week recovery from high lipid overload by tyloxapol and oral-lipid treatment, mice showed an increase in plasma TG and chylomicrons. Upon overnight fasting followed by an oral fat meal, mice showed an increase in plasma TG-rich lipoproteins and particle number of chylomicrons and very low-density lipoproteins. During ageing or after feeding with a high-fat high-cholesterol (HFHC) diet, mice showed an increase in plasma TG, fatty acids, glycerol, and lipoproteins as well as intestinal lipids. HFHC-fed KO mice displayed an increase in body weights, the numbers of lipid droplets with larger sizes in the ileum concomitant with a decrease in ileal ceramides and phosphatidylcholine. Thus, enterocyte FATP4 deficiency led to a metabolic shift from polar to neutral lipids in distal intestine rendering an increase in plasma lipids and lipoproteins.
PubMed: 38915276
DOI: 10.1152/ajpgi.00109.2024 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Jun 2024Cytidine-5'-diphosphate choline (CDP-choline) plays a crucial role in the formation of the phospholipid bilamolecular layer in cell membranes and the stabilization of... (Review)
Review
Cytidine-5'-diphosphate choline (CDP-choline) plays a crucial role in the formation of the phospholipid bilamolecular layer in cell membranes and the stabilization of the neurotransmitter system, acting as a precursor to phosphatidylcholine and acetylcholine. CDP-choline has been found effective in treating functional and consciousness disorders resulting from brain injury, Parkinson's disease, depression and glaucoma, and other conditions. As such, CDP-choline is widely utilized in clinical medicine and health care products. The conventional chemical synthesis process of CDP-choline is gradually being replaced by biosynthesis due to the expensive and toxic reagents involved, the production of various by-products, and the high cost of industrial production. Biosynthesis of CDP-choline offers two strategies: microbial fermentation and biocatalysis. Microbial fermentation utilizes inexpensive raw materials but results in a relatively low conversion rate and requires a complex separation and purification process. Biocatalysis, on the other hand, involves two stages: the growth of a living "catalyst" and the conversion of the substrate. Although the synthetic process in biocatalysis is more complex, it offers a higher conversion ratio, and the downstream processing technique for extraction is relatively less costly. Consequently, biocatalysis is currently the primary strategy for the industrial production of CDP-choline. This review aims to summarize the progress made in both chemical synthesis and biosynthesis of CDP-choline, with particular focus on the metabolic pathway and the synthetic processes involved in biocatalysis, in order to provide insights for the industrial production of CDP-choline.
Topics: Cytidine Diphosphate Choline; Biocatalysis; Fermentation; Humans
PubMed: 38914484
DOI: 10.13345/j.cjb.230715 -
Journal of Chemical Information and... Jun 2024Biological membranes play key roles in cellular compartmentalization, structure, and its signaling pathways. At varying temperatures, individual membrane lipids sample...
Biological membranes play key roles in cellular compartmentalization, structure, and its signaling pathways. At varying temperatures, individual membrane lipids sample from different configurations, a process that frequently leads to higher-order phase behavior and phenomena. Here, we present a persistent homology (PH)-based method for quantifying the structural features of individual and bulk lipids, providing local and contextual information on lipid tail organization. Our method leverages the mathematical machinery of algebraic topology and machine learning to infer temperature-dependent structural information on lipids from static coordinates. To train our model, we generated multiple molecular dynamics trajectories of dipalmitoyl-phosphatidylcholine membranes at varying temperatures. A fingerprint was then constructed for each set of lipid coordinates by PH filtration, in which interaction spheres were grown around the lipid atoms while tracking their intersections. The sphere filtration formed a that captures enduring key of the configuration landscape using homology, yielding . Following fingerprint extraction for physiologically relevant temperatures, the persistence data were used to train an attention-based neural network for assignment of effective temperature values to selected membrane regions. Our persistence homology-based method captures the local structural effects, via effective temperature, of lipids adjacent to other membrane constituents, e.g., sterols and proteins. This topological learning approach can predict lipid effective temperatures from static coordinates across multiple spatial resolutions. The tool, called MembTDA, can be accessed at https://github.com/hyunp2/Memb-TDA.
PubMed: 38912752
DOI: 10.1021/acs.jcim.4c00552 -
Lipids in Health and Disease Jun 2024Observational studies have indicated that the plasma lipid profiles of patients with atopic dermatitis show significant differences compared to healthy individuals....
BACKGROUND
Observational studies have indicated that the plasma lipid profiles of patients with atopic dermatitis show significant differences compared to healthy individuals. However, the causal relationship between these differences remains unclear due to the inherent limitations of observational studies. Our objective was to explore the causal effects between 179 plasma lipid species and atopic dermatitis, and to investigate whether circulating inflammatory proteins serve as mediators in this causal pathway.
METHODS
We utilized public genome-wide association studies data to perform a bidirectional two-sample, two-step mendelian randomization study. The inverse variance-weighted method was adopted as the primary analysis technique. MR-Egger and the weighted median were used as supplementary analysis methods. MR-PRESSO, Cochran's Q test, and MR-Egger intercept test were applied for sensitivity analyses to ensure the robustness of our findings.
RESULTS
The Mendelian randomization analysis revealed that levels of Phosphatidylcholine (PC) (18:1_20:4) (OR: 0.950, 95% CI: 0.929-0.972, p = 6.65 × 10), Phosphatidylethanolamine (O-18:1_20:4) (OR: 0.938, 95% CI: 0.906-0.971, p = 2.79 × 10), Triacylglycerol (TAG) (56:6) (OR: 0.937, 95% CI: 0.906-0.969, p = 1.48 × 10) and TAG (56:8) (OR: 0.918, 95% CI: 0.876-0.961, p = 2.72 × 10) were inversely correlated with the risk of atopic dermatitis. Conversely, PC (18:1_20:2) (OR: 1.053, 95% CI: 1.028-1.079, p = 2.11 × 10) and PC (O-18:1_20:3) (OR: 1.086, 95% CI: 1.039-1.135, p = 2.47 × 10) were positively correlated with the risk of atopic dermatitis. The results of the reverse directional Mendelian randomization analysis indicated that atopic dermatitis exerted no significant causal influence on 179 plasma lipid species. The level of circulating IL-18R1 was identified as a mediator for the increased risk of atopic dermatitis associated with higher levels of PC (18:1_20:2), accounting for a mediation proportion of 9.07%.
CONCLUSION
Our research suggests that plasma lipids can affect circulating inflammatory proteins and may serve as one of the pathogenic factors for atopic dermatitis. Targeting plasma lipid levels as a treatment for atopic dermatitis presents a potentially novel approach.
Topics: Dermatitis, Atopic; Humans; Mendelian Randomization Analysis; Genome-Wide Association Study; Lipids; Triglycerides; Phosphatidylethanolamines; Phosphatidylcholines; Polymorphism, Single Nucleotide
PubMed: 38909247
DOI: 10.1186/s12944-024-02134-9 -
Colloids and Surfaces. B, Biointerfaces Jun 2024The present work explores the specificity of supramolecular assemblies comprising dialkylaminostyrylhetarene dye molecules incorporated into phosphatidylcholine (PC) or...
The present work explores the specificity of supramolecular assemblies comprising dialkylaminostyrylhetarene dye molecules incorporated into phosphatidylcholine (PC) or phosphatidylserine (PS) aggregates. In PS-based assemblies, the dyes demonstrate a concentration-dependent fluorescent response, distinguishing anionic proteins such as bovine serum albumin (BSA) and pepsin from lysozyme (LYZ) in aqueous solutions. Conversely, no significant response is observed when the dyes are incorporated into the well-organized bilayers of neutral PC. The fluorescent response arises from the binding of dyes to proteins, leading to the detachment of dye molecules from the assemblies, rather than from the binding of proteins to the assemblies, although the latter process is facilitated by electrostatic attraction. Thus, both the poor ordering of PS molecules and the interfacial arrangement of the dyes are prerequisites for the fluorescent response of dye-PS aggregates. The structure of the dyes significantly impacts the spectral features of dye-PS and dye-protein assemblies. An optimal dye structure has been identified for the recognition of BSA, with a limit of detection (LOD) of 10.8 nM.
PubMed: 38908044
DOI: 10.1016/j.colsurfb.2024.114046 -
Langmuir : the ACS Journal of Surfaces... Jun 2024The growing reliance on pesticides for pest management in agriculture highlights the need for new analytical methods to detect these substances in food and water. Our...
The growing reliance on pesticides for pest management in agriculture highlights the need for new analytical methods to detect these substances in food and water. Our research introduces a SPRWG-(CH) lipopeptide (LP) as a functional analog of acetylcholinesterase (AChE) for glyphosate detection in environmental samples using phosphatidylcholine (PC) monolayers. This LP, containing hydrophilic amino acids linked to an 18-carbon aliphatic chain, alters lipid assembly properties, leading to a more flexible system. Changes included reduced molecular area and peak pressure in Langmuir adsorption isotherms. Small angle X-ray scattering (SAXS) and atomic force microscopy (AFM) analyses provided insights into the LP's structural organization within the membrane and its interaction with glyphosate (PNG). Structural and geometric parameters, as derived from in silico molecular dynamics simulations (MD), substantiated the impact of LP on the monolayer structure and the interaction with PNG. Notably, the presence of the LP and glyphosate increased charge transfer resistance, indicating strong adherence of the monolayer to the indium tin oxide (ITO) surface and effective pesticide interaction. A calibration curve for glyphosate concentration adjustment revealed a detection limit (LOD) of 24 nmol L, showcasing the high sensitivity of this electrochemical biosensor. This LOD is significantly lower than that of a similar colorimetric biosensor in aqueous media with a detection limit of approximately 0.3 μmol L. Such an improvement in sensitivity likely stems from adding a polar residue to the amino acid chain of the LP.
PubMed: 38907731
DOI: 10.1021/acs.langmuir.4c01089 -
Metabolism: Clinical and Experimental Jun 2024Bariatric surgery improves metabolic health, but the underlying mechanisms are not fully understood. We analyzed the effects of two types of bariatric surgery, sleeve...
OBJECTIVES
Bariatric surgery improves metabolic health, but the underlying mechanisms are not fully understood. We analyzed the effects of two types of bariatric surgery, sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), on the plasma metabolome and lipidome.
METHODS
We characterized the plasma metabolome (1268 metabolites) and lipidome (953 lipids) pre-operatively and at 3 and 12 months post-operatively in 104 obese adults who were previously recruited to a prospective cohort of bariatric surgery. The metabolomic and lipidomic responses to bariatric surgery over time were analyzed using multivariable linear mixed-effects models.
RESULTS
There were significant changes in multiple metabolites and lipids, including rapid early changes in amino acid and peptide metabolites, including decreases in branched-chain amino acids (BCAAs), aromatic AAs, alanine and aspartate, and increases in glycine, serine, arginine and citrulline. There were also significant decreases in many triglyceride species, with increases in phosphatidylcholines and phosphatidylethanolamines. There were significant changes in metabolites related to energy metabolism that were apparent only after 12 months. We observed differences by bariatric surgery type in the changes in a small number of primary and secondary bile acids, including glycohyocholate and glyco-beta-muricholate.
CONCLUSIONS
Our findings highlight the comprehensive changes in metabolites and lipids that occur over the 12 months following bariatric surgery. While both SG and RYGB caused profound changes in the metabolome and lipidome, RYGB was characterized by greater increases in bile acids following surgery.
PubMed: 38906372
DOI: 10.1016/j.metabol.2024.155955 -
Journal of Molecular Modeling Jun 2024Electroporation is a technique that creates electrically generated pores in the cell membrane by modifying transmembrane potential. In this work, the finite element...
CONTEXT
Electroporation is a technique that creates electrically generated pores in the cell membrane by modifying transmembrane potential. In this work, the finite element method (FEM) was used to examine the induced transmembrane voltage (ITV) of a spherical-shaped MCF-7 cell, allowing researchers to determine the stationary ITV. A greater ITV than the critical value causes permeabilization of the membrane. Furthermore, the present study shows how a specific surface conductivity can act as a stand-in for the thin layer that constitutes a cell membrane as the barrier between extracellular and intracellular environments. Additionally, the distribution of ITV on the cell membrane and its maximum value were experimentally evaluated for a range of applied electric fields. Consequently, the entire cell surface area was electroporated 66% and 68% for molecular dynamics (MD) simulations and FEM, respectively, when the external electric field of 1500 V/cm was applied to the cell suspension using the previously indicated numerical methods. Furthermore, the lipid bilayers' molecular structure was changed, which led to the development of hydrophilic holes with a radius of 1.33 nm. Applying MD and FEM yielded threshold values for transmembrane voltage of 700 and 739 mV, respectively.
METHOD
Using MD simulations of palmitoyloleoyl-phosphatidylcholine (POPC), pores in cell membranes exposed to external electric fields were numerically investigated. The dependence on the electric field was estimated and developed, and the amount of the electroporated cell surface area matches the applied external electric field. To investigate more, a mathematical model based on an adaptive neuro-fuzzy inference system (ANFIS) is employed to predict the percent cell viability of cancerous cells after applying four pulses during electroporation. For MD simulations, ArgusLab, VMD, and GROMACS software packages were used. Moreover, for FEM analysis, COMSOL software package was used. Also, it is worth mentioning that for mathematical model, MATLAB software is used.
Topics: Molecular Dynamics Simulation; Humans; Cell Membrane; Electroporation; Finite Element Analysis; Lipid Bilayers; Membrane Potentials; MCF-7 Cells; Electricity; Cell Membrane Permeability; Phosphatidylcholines
PubMed: 38904863
DOI: 10.1007/s00894-024-06012-0 -
The Journal of Physical Chemistry. B Jun 2024Ceramide transfer protein CERT is the mediator of nonvesicular transfer of ceramide from the ER to Golgi. In CERT, START is the domain responsible for the binding and...
Ceramide transfer protein CERT is the mediator of nonvesicular transfer of ceramide from the ER to Golgi. In CERT, START is the domain responsible for the binding and transport of ceramide. A wealth of structural data has revealed a helix-grip fold surrounding a large hydrophobic cavity holding the ceramide. Yet, little is known about the mechanisms by which START releases the ceramide through the polar region and into the packed environment of cellular membranes. As such events do not lend themselves easily to experimental investigations, we used multiple unbiased microsecond-long molecular simulations. We propose a membrane-assisted mechanism in which the membrane acts as an allosteric effector initiating the release of ceramide and where the passage of the ceramide acyl chains is facilitated by the intercalation of a single phosphatidylcholine lipid in the cavity, practically greasing the ceramide way out. We verify using free energy calculation and experimental lipidomics data that CERT forms stable complexes with phosphatidylcholine lipids, in addition to ceramide, thus providing validation for the proposed mechanism.
PubMed: 38903016
DOI: 10.1021/acs.jpcb.4c02398 -
BMC Genomics Jun 2024Global per capita meat consumption continues to rise, especially pork. Meat quality is influenced by the content of intramuscular fat (IMF) as a key factor. The...
BACKGROUND
Global per capita meat consumption continues to rise, especially pork. Meat quality is influenced by the content of intramuscular fat (IMF) as a key factor. The longissimus dorsi muscle of Dahe pigs (DHM, IMF: 7.98% ± 1.96%) and Dahe black pigs (DHBM, IMF: 3.30% ± 0.64%) was studied to explore cellular heterogeneity and differentially expressed genes (DEGs) associated with IMF deposition using single-nucleus RNA sequencing (snRNA-seq). The lipid composition was then analyzed using non-targeted lipidomics.
RESULTS
A total of seven cell subpopulations were identified, including myocytes, fibroblast/fibro/adipogenic progenitors (FAPs), satellite cells, endothelial cells, macrophages, pericytes, and adipocytes. Among them, FAPs and adipocytes were more focused because they could be associated with lipid deposition. 1623 DEGs in the FAPs subpopulation of DHBM were up-regulated compared with DHM, while 1535 were down-regulated. These DEGs enriched in the glycolysis/gluconeogenesis pathway. 109 DEGs were up-regulated and 806 were down-regulated in the adipocyte subpopulation of DHBM compared with DHM, which were mainly enriched in the PPAR signaling pathway and fatty acid (FA) biosynthesis. The expression level of PPARG, ABP4, LEP, and ACSL1 genes in DHM was higher than that in DHBM. Lipidomics reveals porcine lipid composition characteristics of muscle tissue. A total of 41 lipid classes and 2699 lipid species were identified in DHM and DHBM groups. The top ten relative peak areas of lipid classes in DHM and DHBM were triglyceride (TG), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), diglyceride (DG), cardiolipin (CL), ceramides (Cer), Simple Glc series (Hex1Cer), sphingomyelin (phSM), and phosphatidylinositol (PI). The relative peak areas of 35 lipid species in DHM were lower than DHBM, and 28 lipid species that were higher. There was a significant increase in the TG fatty acyl chains C6:0, C17:0, and C11:4, and a significant decrease in C16:0, C18:1, C18:2, and C22:4 in DHBM (p < 0.05).
CONCLUSIONS
C16:0 FA may downregulate the expression level of PPARG gene, which leads to the downregulation of fat metabolism-related genes such as ACSL, PLIN2, and FABP4 in DHBM compared with DHM. This may be the reason that the lipid deposition ability of Dahe pigs is stronger than that of Dahe black pigs, which need further investigation.
Topics: Animals; Swine; Muscle, Skeletal; Lipid Metabolism; Lipidomics; Sequence Analysis, RNA; Single-Cell Analysis; Lipids; Gene Expression Profiling
PubMed: 38902599
DOI: 10.1186/s12864-024-10488-8