Phospholipid Levels Research Articles

Benzodiazepinе derivative methanindiazenone modulates lipid metabolism in the liver of rats with rotenone-induced Parkinson’s syndrome

Parkinson’s disease (PD) is a neurodegenerative condition for which the exact causes remain elusive, and no effective treatments currently exist. The pathogenesis of PD is believed to involve oxidative stress, mitochondrial dysfunction, and lipid metabolism disorders. A benzodiazepine derivative JM-20 has demonstrated protective effects on mitochondria in both neurons and peripheral tissues of rats with rotenoneinduced Parkinson’s syndrome (PS). This study aimed to analyze bile composition and assess the impact of a new benzodiazepine derivative, methanindiazenone, on lipid metabolism in the liver of rats subjected to the rotenone model of PS. The results indicated that, compared to the control group, bile concentration of phospholipids, cholesterol, cholesterol esters, and triglycerides decreased by 24.3, 26.2, 25.8, and 27.5%, respectively. With methanindiazenone treatment at doses of 0.5 and 1.0 mg/kg, all these metrics reverted to the control level. However, in the rotenone+methanindiazenone 2.0 mg/kg group, the levels of phospholipids, cholesterol, and cholesterol esters (except for triglycerides) surpassed the control values by 33, 28.1, 28.4 and 33.5%, respectively. Methanindiazenone positively impacted the motor behavior of rats with the rotenone model of PS and enhanced their survival rates. Therefore, at doses of 0.5 and 1.0 mg/kg, methanindiazenone not only improved lipid metabolism in the liver but also the overall well-being of rats with the rotenone model of PS. However, a 2 mg/kg dose of methanindiazenone displayed toxic effects, as seen from the increased content of phospholipids, cholesterol, and cholesterol esters in bile. Hence, methanindiazenone holds potential as a therapeutic agent for PS and possibly other neurodegenerative diseases related to lipid metabolism impairment, but its use should be limited to doses of 0.5 and 1.0 mg/kg.

Ferroptosis inhibition by oleic acid mitigates iron-overload-induced injury

Iron overload, characterized by accumulation of iron in tissues, induces a multiorgan toxicity whose mechanisms are not fully understood. Using cultured cell lines, Caenorhabditis elegans, and mice, we found that ferroptosis occurs in the context of iron-overload-mediated damage. Exogenous oleic acid protected against iron-overload-toxicity in cell culture and Caenorhabditis elegans by suppressing ferroptosis. In mice, oleic acid protected against FAC-induced liver lipid peroxidation and damage. Oleic acid changed the cellular lipid composition, characterized by decreased levels of polyunsaturated fatty acyl phospholipids and decreased levels of ether-linked phospholipids. The protective effect of oleic acid in cells was attenuated by GW6471 (PPAR-α antagonist), as well as in Caenorhabditis elegans lacking the nuclear hormone receptor NHR-49 (a PPAR-α functional homologue). These results highlight ferroptosis as a driver of iron-overload-mediated damage, which is inhibited by oleic acid. This monounsaturated fatty acid represents a potential therapeutic approach to mitigating organ damage in iron overload individuals.

Serum metabolomics identified specific lipid compounds which may serve as markers of disease progression in patients with Alström and Bardet-Biedl syndromes.

Objectives: Alström syndrome (ALMS) and Bardet-Biedl syndrome (BBS) are among the so-called ciliopathies and are associated with the development of multiple systemic abnormalities, including early childhood obesity and progressive neurodegeneration. Given the progressive deterioration of patients' quality of life, in the absence of defined causal treatment, it seems reasonable to identify the metabolic background of these diseases and search for their progression markers. The aim of this study was to find metabolites characteristic to ALMS and BBS, correlating with clinical course parameters, and related to the diseases progression. Methods: Untargeted metabolomics of serum samples obtained from ALMS and BBS patients (study group; n = 21) and obese/healthy participants (control group; each of 35 participants; n = 70) was performed using LC-QTOF-MS method at the study onset and after 4years of follow-up. Results: Significant differences in such metabolites as valine, acylcarnitines, sphingomyelins, phosphatidylethanolamines, phosphatidylcholines, as well as lysophosphatidylethanolamines and lysophosphatidylcholines were observed when the study group was compared to both control groups. After a follow-up of the study group, mainly changes in the levels of lysophospholipids and phospholipids (including oxidized phospholipids) were noted. In addition, in case of ALMS/BBS patients, correlations were observed between selected phospholipids and glucose metabolism parameters. We also found correlations of several LPEs with patients' age (p < 0.05), but the level of only one of them (hexacosanoic acid) correlated negatively with age in the ALMS/BBS group, but positively in the other groups. Conclusion: Patients with ALMS/BBS have altered lipid metabolism compared to controls or obese subjects. As the disease progresses, they show elevated levels of lipid oxidation products, which may suggest increased oxidative stress. Selected lipid metabolites may be considered as potential markers of progression of ALMS and BBS syndromes.

Influence of acetyl-11-keto-beta boswellic acid on hepatic membrane dynamics and lipidiome during conditions of benzo(a)pyrene induced toxicity

Background and AimPollution and lifestyle changes expose mankind to a number of toxicants such as polycyclic aromatic hydrocarbons that may cause life-threatening diseases. The present study was undertaken to explicate the protective role of Acetyl-11-Keto-Beta Boswellic Acid (AKBA), if any, in containing benzo(a)pyrene (BaP) induced alterations on hepatic membrane dynamics and lipidiome in female rats. Experimental procedureThe animals were divided into five groups viz. Normal control, Vehicle treated, BaP treated, AKBA treated and BaP + AKBA treated. To induce hepatotoxicity, BaP was administered orally at a dose level of 50 mg/kg b.wt. dissolved in olive oil twice a week for 4 weeks. AKBA was supplemented to animals four weeks prior to BaP treatment and continued for 8 weeks at a dose level of 50 mg/kg b.wt. thrice a week. Certain key indices that included oxidative stress biomarkers, lipid profile of membranes, membrane fluidity parameters and activities of ATPases were studied. Results and ConclusionThe results showed that benzo(a)pyrene treatment resulted in a significant increase in the levels of lipid peroxidation (LPO) and ROS but caused a significant decrease in the levels of total lipids, phospholipids, cholesterol, glycolipids and activities of ATPases. Hepatic membrane fluidity as assessed by 1,6-Diphenyl-1,3,5-hexatriene (DPH) and Pyrene fluorescence probes was significantly increased in rats intoxicated with BaP. Interestingly, AKBA supplementation to BaP treated rats appreciably contained altered membrane dynamics and lipidiome as well as modulated hepatotoxicity by skirmishing activities of oxidative stress markers and also improved hepatic histoarchitecture. Our study thus concludes that AKBA can be used as a prophylactic intervention in providing protection to hepatocytes as it maintains membrane integrity in conditions of BaP induced toxicity.

Comparative metabolomics analysis reveals high-altitude adaptations in a toad-headed viviparous lizard, Phrynocephalus vlangalii

Extreme environmental conditions at high altitude, such as hypobaric hypoxia, low temperature, and strong UV radiation, pose a great challenge to the survival of animals. Although the mechanisms of adaptation to high-altitude environments have attracted much attention for native plateau species, the underlying metabolic regulation remains unclear. Here, we used a multi-platform metabolomic analysis to compare metabolic profiles of liver between high- and low-altitude populations of toad-headed lizards, Phrynocephalus vlangalii, from the Qinghai–Tibet Plateau. A total of 191 differential metabolites were identified, consisting of 108 up-regulated and 83 down-regulated metabolites in high-altitude lizards as compared with values for low-altitude lizards. Pathway analysis revealed that the significantly different metabolites were associated with carbohydrate metabolism, amino acid metabolism, purine metabolism, and glycerolipid metabolism. Most intermediary metabolites of glycolysis and the tricarboxylic acid cycle were not significantly altered between the two altitudes, but most free fatty acids as well as β-hydroxybutyric acid were significantly lower in the high-altitude population. This may suggest that high-altitude lizards rely more on carbohydrates as their main energy fuel rather than lipids. Higher levels of phospholipids occurred in the liver of high-altitude populations, suggesting that membrane lipids may undergo adaptive remodeling in response to low-temperature stress at high altitude. In summary, this study demonstrates that metabolic profiles differ substantially between high- and low-altitude lizard populations, and that these differential metabolites and metabolic pathways can provide new insights to reveal mechanisms of adaptation to extreme environments at high altitude.

Electrochemical analysis of total phospholipids in human serum for severe sepsis diagnosis

Electrochemical analysis of total phospholipids was performed for the diagnosis of sepsis. The influence of electrode materials on the analysis of the chromogenic substrate was analyzed using Au, graphite, and pyrolyzed carbon electrodes. The total phospholipid analysis based on electrochemical analysis with pyrolyzed carbon was used for diagnosis of sepsis using sera from healthy volunteers, systemic inflammatory response syndrome (SIRS), and severe sepsis patients. The analysis results using the optical measurement and the electrochemical analysis were compared for the serum samples from sepsis patients and healthy controls. Additionally, the interference of human serum on the optical measurement and electrochemical analysis was estimated by signal-to-noise (S/N) calculation. The assay results of the levels of other biomarkers for sepsis (C-reactive protein and procalcitonin) and the total phospholipid levels obtained using the optical measurement and electrochemical analysis methods were statistically similar. Finally, the mortality of patients, indicated by the results of the total phospholipid assay performed using the electrochemical analysis of the patient samples collected daily (1, 3, and 7 day(s) after admission to hospital), was compared with the patient mortality assessed via conventional severity indexes, such as the SOFA and APACHE Ⅱ scores. The 28-day survival rate was estimated by Kaplan–Meier survival analysis based on the total phospholipid level of patient samples that were obtained after 1, 3, and 7 day(s) from hospital admission.

Untargeted metabolomic profiling in children identifies novel pathways in asthma and atopy

BackgroundAsthma and other atopic disorders can present with varying clinical phenotypes marked by differential metabolomic manifestations and enriched biological pathways. ObjectiveTo identify these unique metabolomic profiles in atopy and asthma. MethodsWe analyzed baseline non-fasted plasma samples from a large multi-site pediatric population of 470 children < 13 years from three different sites in the US and France. Atopy (At+) was defined as skin prick test ≥ 3 mm and/or specific IgE ≥ 0.35 kUi/L, and/or total IgE ≥ 173 IU/mL. Asthma (As+) was based on physician’s diagnosis. The cohort was divided into four groups of varying combinations of As and At and six pairwise analyses were conducted to best assess differential metabolomic profiles between groups. Results210 children were classified as At-As-, 42 as At+As-, 74 as At-As+ and 144 as At+As+. Untargeted global metabolomic profiles were generated through Ultrahigh Performance Liquid Chromatography-Tandem Mass Spectroscopy. We applied two independent machine learning classifiers and shortlisted 362 metabolites as discriminant features. Our analysis showed the most diverse metabolomic profile in the At+As+ / At-As- comparison, followed by the At-As+ / At-As- comparison, indicating that asthma is the most discriminant condition associated with metabolomic changes. At+As+ metabolomic profiles were characterized by higher levels of bile acids, sphingolipids, and phospholipids, and lower levels of polyamine, tryptophan, and gamma-glutamyl amino-acids. ConclusionAt+As+ phenotype displays a distinct metabolomic profile suggesting underlying mechanisms such as modulation of host-pathogen and gut microbiota interactions, epigenetic changes in T-cell differentiation, and lower antioxidant properties of the airway epithelium.

Integration of 16S rRNA gene sequencing and LC/MS-based metabolomic analysis of early biomarkers of acute ischaemic stroke in Tibetan miniature pigs

Acute ischaemic stroke (AIS) is a complex, systemic, pathological, and physiological process. Systemic inflammatory responses and disorders of the gut microbiome contribute to increased mortality and disability following AIS. We conducted 16S high-throughput sequencing and ultra-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry-based non-targeted metabolomic analyses of the plasma from a Tibetan miniature pig middle cerebral artery occlusion (MCAO) model. A significant decrease in the abundance of Firmicutes and a significant increase in the abundance of Actinobacteria were observed after the onset of AIS. Among the plasma metabolites, the levels of phospholipids and amino acids were considerably altered. Loading values and differential metabolite–bacterial group association analyses of the metabolome and microbiome indicated a correlation between the microbiome and metabolome of Tibetan miniature pigs after MCAO. Furthermore, significant changes were observed in the ABC transporter pathway and purine metabolism in the gut microbiome–plasma metabolome during the early stage of AIS. Kyoto Encyclopaedia of Genes and Genomes enrichment analysis showed that arginine, proline, and cyanoamino acid metabolism was upregulated while ABC transporter metabolism pathway and carbohydrate digestion and absorption were substantially downregulated. The results of this study suggest that AIS affects the gut microbiota and plasma metabolites in Tibetan miniature pigs and that faecal microbiota transplantation could be a potential therapeutic approach for AIS.

Effects of dietary forage-to-concentrate ratio and forage type on milk phospholipids and fatty acid composition of polar lipids

The effects of grass silage and red clover silage on milk fatty acid (FA) composition are extensively studied, but little is known of their effects on minor lipid constituents of milk fat globule membrane. We investigated the effects of forage:concentrate (FC) ratio in grass silage-based diets and forage type (grass silage vs. red clover silage) on selected molecular species of milk phospholipids (PL) and the FA composition of PL. Ten multiparous Nordic Red cows were offered following dietary treatments: grass silage-based diets containing 70:30 (HG) or 30:70 (LG) FC ratio or a red clover silage-based diet (RC) comprising 50:50 FC ratio on a dry matter basis. The most abundant molecular species within the phosphatidylcholines was 16:0-18:1 phosphatidylcholine that was increased by 18% in HG compared with LG milk. Dietary treatments did not affect the relative proportion of 18:1-18:1+18:0-18:2 phosphatidylethanolamine that was the most prevalent species (ca. 44%-45%) in that class. We identified the d18:1-22:0 sphingomyelin as the most abundant sphingomyelin species that tended to increase in HG milk compared with LG. The FC ratio did not affect the relative proportions of saturated FA nor monounsaturated FA in PL, but the proportion of cis-9 18:1 was elevated in HG versus LG milk, whereas the proportion of 18:2n-6 was 50% higher in LG versus HG milk. The RC diet increased monounsaturated FA and 18:3n-3 levels in PL compared with grass silage-based diets and decreased the relative proportion of saturated FA. However, the RC diet did not affect the relative proportion of polyunsaturated FA in PL, although red clover silage typically increases the proportion of polyunsaturated FA in milk fat. This study provides valuable knowledge of the minor lipid components in milk on species level in relation to common feeding strategies in high-forage systems.

Protective roles of adiponectin and molecular signatures of HNF4α and PPARα as downstream targets of adiponectin in pancreatic β cells

The disease progression of the metabolic syndrome is associated with prolonged hyperlipidemia and insulin resistance, eventually giving rise to impaired insulin secretion, often concomitant with hypoadiponectinemia. As an adipose tissue derived hormone, adiponectin is beneficial for insulin secretion and β cell health and differentiation. However, the down-stream pathway of adiponectin in the pancreatic islets has not been studied extensively. Here, along with the overall reduction of endocrine pancreatic function in islets from adiponectin KO mice, we examine PPARα and HNF4α as additional down-regulated transcription factors during a prolonged metabolic challenge. To elucidate the function of β cell-specific PPARα and HNF4α expression, we developed doxycycline inducible pancreatic β cell-specific PPARα (β-PPARα) and HNF4α (β-HNF4α) overexpression mice. β-PPARα mice exhibited improved protection from lipotoxicity, but elevated β-oxidative damage in the islets, and also displayed lowered phospholipid levels and impaired glucose-stimulated insulin secretion. β-HNF4α mice showed a more severe phenotype when compared to β-PPARα mice, characterized by lower body weight, small islet mass and impaired insulin secretion. RNA-sequencing of the islets of these models highlights overlapping yet unique roles of β-PPARα and β-HNF4α. Given that β-HNF4α potently induces PPARα expression, we define a novel adiponectin-HNF4α-PPARα cascade. We further analyzed downstream genes consistently regulated by this axis. Among them, the islet amyloid polypeptide (IAPP) gene is an important target and accumulates in adiponectin KO mice. We propose a new mechanism of IAPP aggregation in type 2 diabetes through reduced adiponectin action.

FRI056 Effect Of 48 Hour Of Metreleptin In Humans With Lipodystrophy During Controlled Feeding

Abstract Disclosure: K.M. Bukhari: None. B. Abel: None. R.J. Brown: None. Introduction: The lipodystrophy (LD) syndromes are a rare group of disorders characterized by a generalized or partial loss of adipose tissue resulting in a deficiency of the adipocyte-secreted hormone leptin. Leptin replacement therapy with recombinant human leptin (metreleptin) has favorable effects on the metabolic profile of patients with LD and has been shown to have significant effects on metabolic pathways such as fatty acid oxidation and protein degradation following several months of treatment. However, many of these changes may relate to negative energy balance. Whether these changes can be seen within a few days of initiating metreleptin under energy balance conditions is unknown. Objectives: To explore acute (48 hour) and sub-acute (12 days) metabolomic effects of metreleptin under energy balance conditions in human subjects with leptin deficiency due to LD. Methods: The study included 17 patients with LD (5 generalized LD, 12 partial LD) who were studied on a metabolic ward with food intake held constant to maintain energy balance for 2 weeks. Metreleptin 5 mg q12 hr was administered, and fasting blood samples were collected at baseline (T0), after 2 days of treatment (T2), and after 12 days (T12). Untargeted metabolomic (848 compounds) and lipidomic (984 compounds) analysis was completed with the goal of assessing for any physiologically relevant changes during a period of controlled food intake and prior to any clinically relevant changes in dyslipidemia and diabetes. Statistical analyses between time points were done by paired t-tests. To account for false positives, a false discovery rate (q-value) was calculated for each compound, and only those with P≤0.05 are reported. Results: There was a very consistent reduction in the plasma levels of nearly all lipids detected (except monoacylglycerols) at T2 and T12 compared to T0. This includes plasma levels of phospholipids, ceramides, sphingomyelins, cholesterol esters, diacylglycerols (DAG) and triacylglycerols (TAG). There are significantly lower levels at T12 compared to T2 as well, indicating a continued decrease over time. A number of free fatty acids were significantly lower in the T2 metreleptin treated group compared to T0, with a smaller number that were also lower at T12. These included the medium chain, long chain saturated (palmitate [16:0]), long chain mono- and polyunsaturated (nisinate [24:6n3]). In conjunction with this, the levels of acylcarnitines are lower as well. Other significant changes included evidence of increased aerobic glycolysis with increased demand for pyruvate into the TCA cycle, as well as possible increased branched-chain amino acid catabolism with increased input into the TCA cycle. Conclusion: The effects of metreleptin on metabolism in LD appear to be rapid (48 hours), increase further after 12 days, and are independent from longer term changes in food intake, diabetes, and dyslipidemia. Presentation: Friday, June 16, 2023

Alterations in plasma and erythrocyte membrane fatty acid composition following exposure to toxic copper level affect membrane deformability and fluidity in female wistar rats

BackgroundDeformability and fluidity function of the red blood cell membrane are properties defined by the lipid composition. Toxic copper level induces membrane lipid peroxidation which could cause membrane instability. This study therefore investigated the effect of exposure to toxic copper level for 30 days on red blood cell membrane deformability and fluidity in female Wistar rats. MethodsTwelve (12) female Wistar rats (160 ± 10 g) were randomly grouped (n = 6) into control (given 0.1 ml distilled water p.o.) and copper-toxic (100 mg/kg Copper Sulphate, p.o.), and treated for 30 days. Plasma obtained and RBC membrane prepared from blood collected over EDTA post-treatment were assayed for total cholesterol (TC), phospholipids and fatty acid profile using spectrophotometry and Gas chromatography while heparinized blood was subjected to fragility test. Data were analyzed using student T-test for statistical significance at p < 0.05. Results and conclusionPlasma TC increased by 4.33% while RBC membrane TC decreased by 20.32% in copper-toxic group compared to control. Compared to control, excess copper significantly increased membrane phospholipids level (0.72 ± 0.01 vs 0.59 ± 0.04 mg/dL) but reduced membrane cholesterol/phospholipid ratio (46.61 ± 4.72 vs 72.66 ± 6.47) and stability (by 23.53%). Number of cis- and saturated fatty acids increased in copper-treated plasma and RBC membrane compared to control. Exposure to toxic copper level alters erythrocyte membrane fluidity and deformability by disrupting membrane lipid composition, saturation, bond configuration in phospholipids and permeability.

Sex differences in obesity-induced renal lipid accumulation revealed by lipidomics: a role of adiponectin/AMPK axis

BackgroundSex differences have been observed in the development of obesity-related complications in patients, as well as in animal models. Accumulating evidence suggests that sex-dependent regulation of lipid metabolism contributes to sex-specific physiopathology. Lipid accumulation in the renal tissue has been shown to play a major role in the pathogenesis of obesity-induced kidney injury. Unlike in males, the physiopathology of the disease has been poorly described in females, particularly regarding the lipid metabolism adaptation.MethodsHere, we compared the lipid profile changes in the kidneys of female and male mice fed a high-fat diet (HFD) or low-fat diet (LFD) by lipidomics and correlated them with pathophysiological changes.ResultsWe showed that HFD-fed female mice were protected from insulin resistance and hepatic steatosis compared to males, despite similar body weight gains. Females were particularly protected from renal dysfunction, oxidative stress, and tubular lipid accumulation. Both HFD-fed male and female mice presented dyslipidemia, but lipidomic analysis highlighted differential renal lipid profiles. While both sexes presented similar neutral lipid accumulation with obesity, only males showed increased levels of ceramides and phospholipids. Remarkably, protection against renal lipotoxicity in females was associated with enhanced renal adiponectin and AMP-activated protein kinase (AMPK) signaling. Circulating adiponectin and its renal receptor levels were significantly lower in obese males, but were maintained in females. This observation correlated with the maintained basal AMPK activity in obese female mice compared to males.ConclusionsCollectively, our findings suggest that female mice are protected from obesity-induced renal dysfunction and lipotoxicity associated with enhanced adiponectin and AMPK signaling compared to males.

Oxidized Phospholipid oxPAPC Alters Regulatory T-Cell Differentiation and Decreases Their Protective Function in Atherosclerosis in Mice.

Regulatory T cells (Tregs) are protective in atherosclerosis but reduced during disease progression due to cell death and loss of stability. However, the mechanisms of Treg dysfunction remain unknown. Oxidized phospholipids are abundant in atherosclerosis and can activate innate immune cells, but little is known regarding their impact on T cells. Given Treg loss during atherosclerosis progression and oxidized phospholipid levels in the plaque microenvironment, we investigated whether oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine (oxPAPC), an oxidized phospholipid associated with atherosclerotic plaques, alters Treg differentiation and function. CD4+ T cells were polarized to Treg, T helper (Th) 1, and Th17 cells with or without oxPAPC and assessed by flow cytometry. Gene expression in oxPAPC-treated Tregs was analyzed by bulk RNA sequencing. Functional studies of oxPAPC-induced Tregs were performed by coculturing Tregs with CellTrace Violet-labeled cells in vitro, and by adoptively transferring Tregs to hyperlipidemic Ldlr-/- mice to measure atherosclerosis progression. Compared with controls, oxPAPC-treated Tregs were less viable, but surviving cells expressed higher levels of the Th1-associated markers T-bet, CXCR3, and IFN (interferon)-γ. Th1 and Th17 skewing cultures were unaltered by oxPAPC. IFN-γ is linked to Treg instability, thus Treg polarization experiments were repeated using Ifngr1-/- CD4+ T cells. IFNγR1 (INF gamma receptor 1) deficiency did not improve cell viability in oxPAPC-treated Tregs; however, T-bet and IFN-γ expression was not increased in surviving cells suggesting a role for IFN-γsignaling. OxPAPC-treated Tregs were less suppressive in vitro, and adoptive transfer studies in hyperlipidemic Ldlr-/- mice showed that oxPAPC-induced Tregs possessed altered tissue homing and were insufficient to inhibit atherosclerosis progression. OxPAPC elicits Treg-specific changes altering Treg differentiation and inducing a Th1-like phenotype in surviving cells partially through IFN-γ signaling. This is biologically relevant as oxPAPC-treated Tregs do not reduce atherosclerosis progression in Ldlr-/- mice. This study supports the role of oxidized phospholipids in negatively impacting Treg differentiation and atheroprotective function.

Blood-derived lysophospholipid sustains hepatic phospholipids and fat storage necessary for hepatoprotection in overnutrition.

The liver has a high demand for phosphatidylcholine (PC), particularly in overnutrition, where reduced phospholipid levels have been implicated in the development of nonalcoholic fatty liver disease (NAFLD). Whether other pathways exist in addition to de novo PC synthesis that contribute to hepatic PC pools remains unknown. Here, we identified the lysophosphatidylcholine (LPC) transporter major facilitator superfamily domain containing 2A (Mfsd2a) as critical for maintaining hepatic phospholipid pools. Hepatic Mfsd2a expression was induced in patients having NAFLD and in mice in response to dietary fat via glucocorticoid receptor action. Mfsd2a liver-specific deficiency in mice (L2aKO) led to a robust nonalcoholic steatohepatitis-like (NASH-like) phenotype within just 2 weeks of dietary fat challenge associated with reduced hepatic phospholipids containing linoleic acid. Reducing dietary choline intake in L2aKO mice exacerbated liver pathology and deficiency of liver phospholipids containing polyunsaturated fatty acids (PUFAs). Treating hepatocytes with LPCs containing oleate and linoleate, two abundant blood-derived LPCs, specifically induced lipid droplet biogenesis and contributed to phospholipid pools, while LPC containing the omega-3 fatty acid docosahexaenoic acid (DHA) promoted lipid droplet formation and suppressed lipogenesis. This study revealed that PUFA-containing LPCs drive hepatic lipid droplet formation, suppress lipogenesis, and sustain hepatic phospholipid pools - processes that are critical for protecting the liver from excess dietary fat.

Alveolar type II epithelial cell FASN maintains lipid homeostasis in experimental COPD.

Alveolar epithelial type II (AEC2) cells strictly regulate lipid metabolism to maintain surfactant synthesis. Loss of AEC2 cell function and surfactant production are implicated in the pathogenesis of the smoking-related lung disease chronic obstructive pulmonary disease (COPD). Whether smoking alters lipid synthesis in AEC2 cells and whether altering lipid metabolism in AEC2 cells contributes to COPD development are unclear. In this study, high-throughput lipidomic analysis revealed increased lipid biosynthesis in AEC2 cells isolated from mice chronically exposed to cigarette smoke (CS). Mice with a targeted deletion of the de novo lipogenesis enzyme, fatty acid synthase (FASN), in AEC2 cells (FasniΔAEC2) exposed to CS exhibited higher bronchoalveolar lavage fluid (BALF) neutrophils, higher BALF protein, and more severe airspace enlargement. FasniΔAEC2 mice exposed to CS had lower levels of key surfactant phospholipids but higher levels of BALF ether phospholipids, sphingomyelins, and polyunsaturated fatty acid-containing phospholipids, as well as increased BALF surface tension. FasniΔAEC2 mice exposed to CS also had higher levels of protective ferroptosis markers in the lung. These data suggest that AEC2 cell FASN modulates the response of the lung to smoke by regulating the composition of the surfactant phospholipidome.

ANTI-ATHEROGENIC ACTIVITY OF ETHYL ACETATE AND ETHANOLIC EXTRACTS OF CAESALPINIA BONDUCELLA LINN.F. ON HIGH-FAT DIET-INDUCED ATHEROSCLEROSIS IN RATS

Objective: The aim is to investigate the anti-atherogenic effect of ethyl acetate (EACB) and ethanolic extracts of Caesalpinia bonducella (ETCB) kernels against high-fat diet (HFD) induced atherosclerosis (AS) in male Wistar rats. Methods: Rats were divided into seven groups of six each. Group I served as normal control, group II received HFD (20.5% of wheat flour, 52.6% of roasted bengal gram, 5% of skimmed milk powder, 4% of refined oil, 4% of casein, 4% starch with salt mixture, 9% of coconut oil, 0.5% of choline mixture and vitamin and 0.4% of cholesterol), group III received HFD+Standard drug atorvastatin (1.2 mg/kg b.w.) and the remaining four groups IV, V, VI, and VII received HFD along with EACB (100 and 200 mg/kg b.wt) and HFD along with ETCB (100 and 200 mg/kg b.wt) respectively for 90 days. Anti-atherogenic activity was assessed by quantifying the concentration of serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) cholesterol, high-density lipoprotein cholesterol, very LDL cholesterol, and phospholipids (PL). Tissue levels of TC, TG, and PL were also determined. Lipid peroxidation and enzymatic anti-oxidants were determined in the liver, heart, and aorta tissue. The histopathological analysis of the liver and aorta tissue supported the dose-dependent anti-atherogenic effects of EACB and ETCB. Results: EACB and ETCB significantly (p≤0.05) protected the above-mentioned parameters to fall from the normal levels. Conclusion: These observations suggest that the EACB and ETCB have a dose-dependent anti-atherogenic effect against HFD-induced AS.

Antioxidants ameliorate oxidative stress in alcoholic liver injury by modulating lipid metabolism and phospholipid homeostasis.

Alcoholic liver disease (ALD) is a significant risk factor in the global disease burden. The antioxidants vitamin C (Vc) and N-acetyl cysteine (NAC) have shown hepatoprotective effects in preventing and treating ALD. However, the correlation between the improved effect of antioxidants and lipid metabolism is still unclear. In this study, AML12 cells and C57BL/6 mice stimulated with alcohol were used to investigate the protective effects and potential mechanisms of two antioxidants (Vc and NAC) on alcoholic liver injury. Results showed that Vc and NAC attenuated intracellular lipid accumulation and oxidative damage induced by excessive alcohol exposure in hepatic AML12 cells. The in vivo results indicated that antioxidants ameliorated alcohol-induced changes in histopathology, reducing the levels of alcohol metabolizing factors and aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglyceride (TG), and total cholesterol (TC) contents, which demonstrated that antioxidants effectively mitigated liver injury in ALD mice. Further studies showed that antioxidants reversed the disruption of fatty acid (FA) synthesis and lipid transport induced by alcohol exposure, and restored phospholipid levels. Especially, Vc and NAC increased the endogenous antioxidant plasmenyl phosphatidylethanolamine (PlsEtn). Additionally, antioxidants ameliorated the alcohol-impaired mitochondrial function and inhibited excessive oxidative stress. In conclusion, antioxidants can regulate lipid metabolism and phospholipid homeostasis, which in turn inhibit oxidative stress and thereby exert protective effects against ALD.

Outcomes of 38 patients with PFIC3: Impact of genotype and of response to ursodeoxycholic acid therapy

Progressive familial intrahepatic cholestasis type 3 (PFIC3) is a rare liver disease caused by biallelic variations in ABCB4. Data reporting on the impact of genotype and of response to ursodeoxycholic acid (UDCA) therapy on long-term outcomes are scarce. We retrospectively describe a cohort of 38 patients with PFIC3 with a median age at last follow-up of 19.5 years (range 3.8-53.8). Twenty patients presented with symptoms before 1 year of age. Thirty-one patients received ursodeoxycholic acid (UDCA) therapy resulting in serum liver test improvement in 20. Twenty-seven patients had cirrhosis at a median age of 8.1 years of whom 18 received a liver transplant at a median age of 8.5 years. Patients carrying at least one missense variation were more likely to present with positive (normal or decreased) canalicular MDR3 expression in the native liver and had prolonged native liver survival (NLS; median 12.4 years [range 3.8-53.8]). In contrast, in patients with severe genotypes (no missense variation), there was no detectable canalicular MDR3 expression, symptom onset and cirrhosis occurred earlier, and all underwent liver transplantation (at a median age of 6.7 years [range 2.3-10.3]). The latter group was refractory to UDCA treatment, whereas 87% of patients with at least one missense variation displayed an improvement in liver biochemistry in response to UDCA. Biliary phospholipid levels over 6.9% of total biliary lipid levels predicted response to UDCA. Response to UDCA predicted NLS. Patients carrying at least one missense variation, with positive canalicular expression of MDR3 and a biliary phospholipid level over 6.9% of total biliary lipid levels were more likely to respond to UDCA and to exhibit prolonged NLS. In this study, data show that genotype and response to ursodeoxycholic acid therapy predicted native liver survival in patients with PFIC3 (progressive familial intrahepatic cholestasis type 3). Patients carrying at least one missense variation, with positive (decreased or normal) immuno-staining for canalicular MDR3, and a biliary phospholipid level over 6.9% of total biliary lipids were more likely to respond to ursodeoxycholic acid therapy and to exhibit prolonged native liver survival.

A novel detection method for neuronal death indicates abnormalities in intracellular membranous components in neuronal cells that underwent delayed death.

Acute neuronal degeneration is always preceded under the light and electron microscopes by a stage called microvacuolation, which is characterized by a finely vacuolar alteration in the cytoplasm of the neurons destined to death. In this study, we reported a method for detecting neuronal death using two membrane-bound dyes, rhodamine R6 and DiOC6(3), which may be associated with the so-called microvacuolation. This new method produced a spatiotemporally similar staining pattern to Fluoro-Jade B in kainic acid-damaged brains in mice. Further experiments showed that increased staining of rhodamine R6 and DiOC6(3) was observed only in degenerated neurons, but not in glia, erythrocytes, or meninges. Different from Fluoro-Jade-related dyes, rhodamine R6 and DiOC6(3) staining is highly sensitive to solvent extraction and detergent exposure. Staining with Nile red for phospholipids and filipin III for non-esterified cholesterol supports that the increased staining of rhodamine R6 and DiOC6(3) might be associated with increased levels of phospholipids and free cholesterol in the perinuclear cytoplasm of damaged neurons. In addition to kainic acid-injected neuronal death, rhodamine R6 and DiOC6(3) were similarly useful for detecting neuronal death in ischemic models either in vivo or in vitro. As far as we know, the staining with rhodamine R6 or DiOC6(3) is one of a few histochemical methods for detecting neuronal death whose target molecules have been well defined and therefore may be useful for explaining experimental results as well as exploring the mechanisms of neuronal death.