scholarly journals Lipid Remodeling Confers Osmotic Stress Tolerance to Embryogenic Cells during Cryopreservation

2021 ◽  
Vol 22 (4) ◽  
pp. 2174
Author(s):  
Liang Lin ◽  
Junchao Ma ◽  
Qin Ai ◽  
Hugh W. Pritchard ◽  
Weiqi Li ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Technology Development ◽  
Membrane Lipids ◽  
Species Conservation ◽  
Membrane Lipid ◽  
Cell Integrity ◽  
Embryogenic Cells ◽  
Osmotic Stress Tolerance ◽  
Lipid Species ◽  
Magnolia Officinalis

Plant species conservation through cryopreservation using plant vitrification solutions (PVS) is based in empiricism and the mechanisms that confer cell integrity are not well understood. Using ESI-MS/MS analysis and quantification, we generated 12 comparative lipidomics datasets for membranes of embryogenic cells (ECs) of Magnolia officinalis during cryogenic treatments. Each step of the complex PVS-based cryoprotocol had a profoundly different impact on membrane lipid composition. Loading treatment (osmoprotection) remodeled the cell membrane by lipid turnover, between increased phosphatidic acid (PA) and phosphatidylglycerol (PG) and decreased phosphatidylcholine (PC) and phosphatidylethanolamine (PE). The PA increase likely serves as an intermediate for adjustments in lipid metabolism to desiccation stress. Following PVS treatment, lipid levels increased, including PC and PE, and this effectively counteracted the potential for massive loss of lipid species when cryopreservation was implemented in the absence of cryoprotection. The present detailed cryobiotechnology findings suggest that the remodeling of membrane lipids and attenuation of lipid degradation are critical for the successful use of PVS. As lipid metabolism and composition varies with species, these new insights provide a framework for technology development for the preservation of other species at increasing risk of extinction.

scholarly journals Membrane Lipids’ Metabolism and Transcriptional Regulation in Maize Roots Under Cold Stress

2021 ◽  
Vol 12 ◽  
Author(s):  
Xunchao Zhao ◽  
Yulei Wei ◽  
Jinjie Zhang ◽  
Li Yang ◽  
Xinyu Liu ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Low Temperature ◽  
Cold Stress ◽  
Temperature Stress ◽  
Membrane Lipids ◽  
Membrane Lipid ◽  
Metabolic Changes ◽  
Low Temperature Stress ◽  
Maize Seedlings ◽  
Maize Roots

Low temperature is one of the major abiotic stresses that restrict the growth and development of maize seedlings. Membrane lipid metabolism and remodeling are key strategies for plants to cope with temperature stresses. In this study, an integrated lipidomic and transcriptomic analysis was performed to explore the metabolic changes of membrane lipids in the roots of maize seedlings under cold stress (5°C). The results revealed that major extraplastidic phospholipids [phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidic acid (PA), and phosphatidylinositol (PI)] were dominant membrane lipids in maize root tissues, accounting for more than 70% of the total lipids. In the transcriptome data of maize roots under cold stress, a total of 189 lipid-related differentially expressed genes (DEGs) were annotated and classified into various lipid metabolism pathways, and most of the DEGs were enriched in the “Eukaryotic phospholipid synthesis” (12%), “Fatty acid elongation” (12%), and “Phospholipid signaling” (13%) pathways. Under low temperature stress, the molar percentage of the most abundant phospholipid PC decreased around 10%. The significantly up-regulated expression of genes encoding phospholipase [phospholipase D (PLD)] and phosphatase PAP/LPP genes implied that PC turnover was triggered by cold stress mainly via the PLD pathway. Consequently, as the central product of PC turnover, the level of PA increased drastically (63.2%) compared with the control. The gene-metabolite network and co-expression network were constructed with the prominent lipid-related DEGs to illustrate the modular regulation of metabolic changes of membrane lipids. This study will help to explicate membrane lipid remodeling and the molecular regulation mechanism in field crops encountering low temperature stress.

scholarly journals Comparison of Erythrocyte Membrane Lipid Profiles between NAFLD Patients with or without Hyperlipidemia

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Wenbin Chen ◽  
Shanshan Shao ◽  
Hu Cai ◽  
Jie Han ◽  
Tian Guo ◽  
...  
Keyword(s):  
Erythrocyte Membrane ◽  
Cell Function ◽  
Membrane Lipids ◽  
Weight Percent ◽  
Membrane Lipid ◽  
Lipid Profiles ◽  
Data Sets ◽  
Lipid Profiling ◽  
Nonalcoholic Fatty Liver ◽  
Lipid Species

Objectives. Nonalcoholic fatty liver disease (NAFLD) and hyperlipidemia (HL) are common metabolic disorders due to overnutrition and obesity. NAFLD is often associated with hyperlipidemia. The aim of this study was to identify and compare the erythrocyte membrane lipids profile in NAFLD patients with or without HL. Methods. A total of 112 subjects (with similar age and body mass index) were divided into four groups: (1) normal controls, (2) NAFLD alone, (3) HL alone, and (4) NAFLD combined with HL (NAFLD + HL). Lipid was extracted from the erythrocyte membrane, and lipid profiles of subjects were analyzed by liquid chromatography mass spectrometry (LC-MS). Results. Data sets from 103 subjects were adopted for lipidomic analysis. Significant changes of lipid species were observed in patient groups, especially in the HL group and NAFLD + HL group. The HL group showed increased level of most lipid species, and decreased level of most lipid species was observed in the NAFLD + HL group. The weight percent of myristic acid, stearic acid, erucic acid, and docosahexaenoic acid also showed distinct variation between different groups. Conclusions. NAFLD, HL, and NAFLD + HL all had an impact on lipid profiling of the erythrocyte membrane. The influence of NAFLD alone is less important compared with HL. Some lipids should be highlighted because of their specific role in cell function and systemic metabolism.

Microscopy of membrane lipids: how precisely can we define their distribution?

2015 ◽  
Vol 57 ◽  
pp. 81-91 ◽  
Author(s):  
Sho Takatori ◽  
Toyoshi Fujimoto
Keyword(s):  
Membrane Lipids ◽  
Freeze Fracture ◽  
Practical Method ◽  
Membrane Lipid ◽  
Electron Microscopic ◽  
Functional Roles ◽  
Lipid Dynamics ◽  
Lipid Species ◽  
Quick Freezing ◽  
The Moment

Membrane lipids form the basic framework of biological membranes by forming the lipid bilayer, but it is becoming increasingly clear that individual lipid species play different functional roles. However, in comparison with proteins, relatively little is known about how lipids are distributed in the membrane. Several microscopic methods are available to study membrane lipid dynamics in living cells, but defining the distribution of lipids at the submicrometre scale is difficult, because lipids diffuse quickly in the membrane and most lipids do not react with aldehydes that are commonly used as fixatives. Quick-freezing appears to be the only practical method by which to stop the lipid movement instantaneously and capture the molecular localization at the moment of interest. Electron microscopic methods, using cryosections, resin sections, and freeze-fracture replicas are used to visualize lipids in quick-frozen samples. The method that employs the freeze-fracture replica is unique in that it requires no chemical treatment and provides a two-dimensional view of the membrane.

scholarly journals The mitochondrial intermembrane space–facing proteins Mcp2 and Tgl2 are involved in yeast lipid metabolism

2019 ◽  
Vol 30 (21) ◽  
pp. 2681-2694
Author(s):  
Fenja Odendall ◽  
Sandra Backes ◽  
Takashi Tatsuta ◽  
Uri Weill ◽  
Maya Schuldiner ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Membrane Lipids ◽  
Genetic Interaction ◽  
Proper Function ◽  
Intermembrane Space ◽  
Gene Encoding ◽  
Double Deletion ◽  
Lipid Species ◽  
Mitochondrial Lipid ◽  
Cellular Compartments

Mitochondria are unique organelles harboring two distinct membranes, the mitochondrial inner and outer membrane (MIM and MOM, respectively). Mitochondria comprise only a subset of metabolic pathways for the synthesis of membrane lipids; therefore most lipid species and their precursors have to be imported from other cellular compartments. One such import process is mediated by the ER mitochondria encounter structure (ERMES) complex. Both mitochondrial membranes surround the hydrophilic intermembrane space (IMS). Therefore, additional systems are required that shuttle lipids between the MIM and MOM. Recently, we identified the IMS protein Mcp2 as a high-copy suppressor for cells that lack a functional ERMES complex. To understand better how mitochondria facilitate transport and biogenesis of lipids, we searched for genetic interactions of this suppressor. We found that MCP2 has a negative genetic interaction with the gene TGL2 encoding a neutral lipid hydrolase. We show that this lipase is located in the intermembrane space of the mitochondrion and is imported via the Mia40 disulfide relay system. Furthermore, we show a positive genetic interaction of double deletion of MCP2 and PSD1, the gene encoding the enzyme that synthesizes the major amount of cellular phosphatidylethanolamine. Finally, we demonstrate that the nucleotide-binding motifs of the predicted atypical kinase Mcp2 are required for its proper function. Taken together, our data suggest that Mcp2 is involved in mitochondrial lipid metabolism and an increase of this involvement by overexpression suppresses loss of ERMES.

scholarly journals The p97-UBXD8 complex modulates ER-Mitochondria contact sites by modulating membrane lipid saturation and composition

2021 ◽  
Author(s):  
Rakesh Ganji ◽  
Joao A. Paulo ◽  
Yuecheng Xi ◽  
Ian Kline ◽  
Jiang Zhu ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Lipid Composition ◽  
Unsaturated Fatty Acids ◽  
Lipid Synthesis ◽  
Membrane Lipid ◽  
Loss Of Function ◽  
Membrane Lipid Composition ◽  
Aaa Atpase ◽  
Contact Sites ◽  
Lipid Species

AbstractThe intimate association between the endoplasmic reticulum (ER) and mitochondrial membranes at ER-mitochondria contact sites serves as a platform for several critical cellular processes, in particular lipid synthesis. Enzymes involved in lipid biosynthesis are enriched at contacts and membrane lipid composition at contacts is distinct relative to surrounding membranes. How contacts are remodeled and the subsequent biological consequences of altered contacts such as perturbed lipid metabolism remains poorly understood. Here we show that the p97 AAA-ATPase and its ER-tethered ubiquitin-X domain adaptor 8 (UBXD8) regulate the prevalence of ER-mitochondria contacts. The p97-UBXD8 complex localizes to contacts and loss of this complex increases contacts in a manner that is dependent on p97 catalytic activity. Quantitative proteomics of purified contacts demonstrates alterations in proteins regulating lipid metabolism upon loss of UBXD8. Furthermore, lipidomics studies indicate significant changes in distinct lipid species in UBXD8 knockout cells. We show that loss of p97-UBXD8 results in perturbed contacts due to an increase in membrane lipid saturation via SREBP1 and the lipid desaturase SCD1. Aberrant contacts in p97-UBXD8 loss of function cells can be rescued by supplementation with unsaturated fatty acids or overexpression of SCD1. Perturbation of contacts and inherent lipid synthesis is emerging as a hallmark to a variety of human disorders such as neurodegeneration. Notably, we find that the SREBP1-SCD1 pathway is negatively impacted in the brains of mice with p97 mutations that cause neurodegeneration. Our results suggest that contacts are exquisitely sensitive to alterations to membrane lipid composition and saturation in a manner that is dependent on p97-UBXD8.

scholarly journals The Adjustment of Membrane Lipid Metabolism Pathways in Maize Roots Under Saline–Alkaline Stress

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaoxuan Xu ◽  
Jinjie Zhang ◽  
Bowei Yan ◽  
Yulei Wei ◽  
Shengnan Ge ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Stress Responses ◽  
Membrane Lipids ◽  
Membrane Lipid ◽  
Alkaline Stress ◽  
Expression Of Genes ◽  
Phosphatidic Acid Phosphatase ◽  
Maize Roots ◽  
Regulated Expression ◽  
Genes Encoding

Plants are frequently confronted by diverse environmental stress, and the membrane lipids remodeling and signaling are essential for modulating the stress responses. Saline–alkaline stress is a major osmotic stress affecting the growth and development of crops. In this study, an integrated transcriptomic and lipidomic analysis was performed, and the metabolic changes of membrane lipid metabolism in maize (Zea mays) roots under saline–alkaline stress were investigated. The results revealed that phospholipids were major membrane lipids in maize roots, and phosphatidylcholine (PC) accounts for approximately 40% of the total lipids. Under 100 mmol NaHCO3 treatment, the level of PC decreased significantly (11–16%) and the parallel transcriptomic analysis showed an increased expression of genes encoding phospholipase A and phospholipase D/non-specific phospholipase C, which suggested an activated PC turnover under saline–alkaline stress. The plastidic galactolipid synthesis was also activated, and an abnormal generation of C34:6 galactolipids in 18:3 plants maize implied a plausible contribution from the prokaryotic pathway, which could be partially supported by the up-regulated expression of three putative plastid-localized phosphatidic acid phosphatase/lipid phosphate phosphatase. A comprehensive gene–metabolite network was constructed, and the regulation of membrane lipid metabolism under saline–alkaline stress in maize was discussed.

scholarly journals Defining how multiple lipid species interact with inward rectifier potassium (Kir2) channels

2020 ◽  
Vol 117 (14) ◽  
pp. 7803-7813 ◽  
Author(s):  
Anna L. Duncan ◽  
Robin A. Corey ◽  
Mark S. P. Sansom
Keyword(s):  
Plasma Membrane ◽  
Membrane Lipids ◽  
Membrane Lipid ◽  
Inward Rectifier ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Anionic Lipid ◽  
Lipid Interactions ◽  
Interaction Sites ◽  
Lipid Species

Protein–lipid interactions are a key element of the function of many integral membrane proteins. These potential interactions should be considered alongside the complexity and diversity of membrane lipid composition. Inward rectifier potassium channel (Kir) Kir2.2 has multiple interactions with plasma membrane lipids: Phosphatidylinositol (4, 5)-bisphosphate (PIP2) activates the channel; a secondary anionic lipid site has been identified, which augments the activation by PIP2; and cholesterol inhibits the channel. Molecular dynamics simulations are used to characterize in molecular detail the protein–lipid interactions of Kir2.2 in a model of the complex plasma membrane. Kir2.2 has been simulated with multiple, functionally important lipid species. From our simulations we show that PIP2interacts most tightly at the crystallographic interaction sites, outcompeting other lipid species at this site. Phosphatidylserine (PS) interacts at the previously identified secondary anionic lipid interaction site, in a PIP2concentration-dependent manner. There is interplay between these anionic lipids: PS interactions are diminished when PIP2is not present in the membrane, underlining the need to consider multiple lipid species when investigating protein–lipid interactions.

scholarly journals Criticality of plasma membrane lipids reflects activation state of macrophage cells

2019 ◽  
Author(s):  
Eugenia Cammarota ◽  
Chiara Soriani ◽  
Raphaelle Taub ◽  
Fiona Morgan ◽  
Jiro Sakai ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Critical Point ◽  
Membrane Lipids ◽  
Membrane Lipid ◽  
Membrane Receptors ◽  
Critical Conditions ◽  
Membrane Composition ◽  
Macrophage Cells ◽  
Lipid Species ◽  
Anti Inflammatory

AbstractSignalling is of particular importance in immune cells, and upstream in the signalling pathway many membrane receptors are functional only as complexes, co-locating with particular lipid species. Work over the last 15 years has shown that plasma membrane lipid composition is close to a critical point of phase separation, with evidence that cells adapt their composition in ways that alter the proximity to this thermodynamical point. Macrophage cells are a key component of the innate immune system, responsive to infections, regulating the local state of inflammation. We investigate changes in the plasma membrane’s proximity to the critical point, as a response to stimulation by various pro- and anti-inflammatory agents. Pro-inflammatory (IFN-γ, Kdo-LipidA, LPS) perturbations induce an increase in the transition temperature of the GMPVs; anti-inflammatory IL4 has the opposite effect. These changes recapitulate complex plasma membrane composition changes, and are consistent with lipid criticality playing a master regulatory role: being closer to critical conditions increases membrane protein activity.

scholarly journals How does hepatic lipid accumulation lead to lipotoxicity in non-alcoholic fatty liver disease?

2021 ◽  
Vol 15 (1) ◽  
pp. 21-35
Author(s):  
Yana Geng ◽  
Klaas Nico Faber ◽  
Vincent E. de Meijer ◽  
Hans Blokzijl ◽  
Han Moshage
Keyword(s):  
Lipid Metabolism ◽  
Liver Disease ◽  
Fatty Liver ◽  
Lipid Accumulation ◽  
Fatty Liver Disease ◽  
Lipid Uptake ◽  
Cellular Mechanisms ◽  
Alcoholic Fatty Liver ◽  
Lipid Species ◽  
Alcoholic Fatty Liver Disease

Abstract Background Non-alcoholic fatty liver disease (NAFLD), characterized as excess lipid accumulation in the liver which is not due to alcohol use, has emerged as one of the major health problems around the world. The dysregulated lipid metabolism creates a lipotoxic environment which promotes the development of NAFLD, especially the progression from simple steatosis (NAFL) to non-alcoholic steatohepatitis (NASH). Purposeand Aim This review focuses on the mechanisms of lipid accumulation in the liver, with an emphasis on the metabolic fate of free fatty acids (FFAs) in NAFLD and presents an update on the relevant cellular processes/mechanisms that are involved in lipotoxicity. The changes in the levels of various lipid species that result from the imbalance between lipolysis/lipid uptake/lipogenesis and lipid oxidation/secretion can cause organellar dysfunction, e.g. ER stress, mitochondrial dysfunction, lysosomal dysfunction, JNK activation, secretion of extracellular vesicles (EVs) and aggravate (or be exacerbated by) hypoxia which ultimately lead to cell death. The aim of this review is to provide an overview of how abnormal lipid metabolism leads to lipotoxicity and the cellular mechanisms of lipotoxicity in the context of NAFLD.

scholarly journals Triple-Knockout, Synuclein-Free Mice Display Compromised Lipid Pattern

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3078
Author(s):  
Irina A. Guschina ◽  
Natalia Ninkina ◽  
Andrei Roman ◽  
Mikhail V. Pokrovskiy ◽  
Vladimir L. Buchman
Keyword(s):  
Fatty Acids ◽  
Lipid Metabolism ◽  
Family Members ◽  
Ether Lipid ◽  
Brain Regions ◽  
Membrane Lipid ◽  
Lipid Binding ◽  
Synaptic Functions ◽  
Ethanolamine Plasmalogens ◽  
Lipid Pattern

Recent studies have implicated synucleins in several reactions during the biosynthesis of lipids and fatty acids in addition to their recognised role in membrane lipid binding and synaptic functions. These are among aspects of decreased synuclein functions that are still poorly acknowledged especially in regard to pathogenesis in Parkinson’s disease. Here, we aimed to add to existing knowledge of synuclein deficiency (i.e., the lack of all three family members), with respect to changes in fatty acids and lipids in plasma, liver, and two brain regions in triple synuclein-knockout (TKO) mice. We describe changes of long-chain polyunsaturated fatty acids (LCPUFA) and palmitic acid in liver and plasma, reduced triacylglycerol (TAG) accumulation in liver and non-esterified fatty acids in plasma of synuclein free mice. In midbrain, we observed counterbalanced changes in the relative concentrations of phosphatidylcholine (PC) and cerebrosides (CER). We also recorded a notable reduction in ethanolamine plasmalogens in the midbrain of synuclein free mice, which is an important finding since the abnormal ether lipid metabolism usually associated with neurological disorders. In summary, our data demonstrates that synuclein deficiency results in alterations of the PUFA synthesis, storage lipid accumulation in the liver, and the reduction of plasmalogens and CER, those polar lipids which are principal compounds of lipid rafts in many tissues. An ablation of all three synuclein family members causes more profound changes in lipid metabolism than changes previously shown to be associated with γ-synuclein deficiency alone. Possible mechanisms by which synuclein deficiency may govern the reported modifications of lipid metabolism in TKO mice are proposed and discussed.

Sign in / Sign up

Export Citation Format

Share Document