Levels Of Esters Research Articles

Multi‐omic profiling of isogenic ApoE3/3 and ApoE4/4 iPSC‐derived astrocytes uncovers altered lipid metabolism and mitochondrial function of ApoE4 astrocytes

AbstractBackgroundAs the main genetic risk factor for AD, glial ApoE4 has been implicated in a number of early disease relevant processes, such as lipid dyshomeostasis, mitochondrial dysfunction and altered immune function. This ApoE4 glial phenotype is not yet well characterized and this hampers the rationale design of ApoE4‐targeting interventions.MethodWe characterize the phenotypes of ApoE3/3 and ApoE4/4 iPSC‐derived astrocytes by multi‐omic profiling. In addition, we use lipidomic and metabolic profiling of interventions in ApoE4 astrocytes to define compounds that normalize lipid counts and metabolic function.ResultIn the ApoE4 astrocytes we observe strong accumulation of cholesterol esters (storage product of cholesterol) and triglycerides (storage products of fatty acids), in comparison to the ApoE3 astrocytes. Interestingly, our proteomic and transcriptomic profiling of these cells reveal an increase in cholesterol synthesis, despite the already high levels of cholesterol esters in the cell. Moreover, our proteomic and transcriptomic results display an increase in mitochondrial pathways, such as beta‐oxidation, TCA cycle and oxidative phosphorylation and a decrease in glycolysis. Not only mitochondrial function is altered but also mitochondrial organization, as we see an upregulation of the most relevant proteins for mitochondrial fusion, MFN1, MFN2 and OPA1. Our lipidomic and metabolic profiling of ApoE4 astrocytes after treatment with a number of different interventions reveals new insights into these altered lipid metabolic pathways.ConclusionOur multi‐omic profiling of iPSC‐derived ApoE3/3 and ApoE4/4 astrocytes uncovers that ApoE4 astrocytes have altered lipid metabolism, mitochondrial function and mitochondrial organization. Treatment with interventions reveals new insights into these altered pathways.

The relationship between ApoE4 and lipid dysregulation in glia of the PS19 mouse model of tauopathy

AbstractBackgroundApolipoprotein E4 (apoE), the major lipoprotein in the brain, plays an essential role in brain`s lipid homeostasis; furthermore, the presence of the apoE4 allele is the strongest genetic risk factor for developing late‐onset AD compared to most common apoE3 and protective apoE2 alleles. Recent studies in iPSC microglia and astrocytes demonstrate that apoE modulates cholesterol dysfunction and inflammatory responses in an isoform‐specific fashion. However, it is not known if lipid accumulation in glia mediates toxic effects in vivo in the context of tauopathy and neurodegeneration.MethodIn this work we used the combination unbiased lipidomics coupled with immunostainings to dissect the role of apoE and apoE isoforms in glial lipid metabolism of tauopathy P301S tau transgenic mice with a targeted replacement of murine apoE with human ApoE4, ApoE3, or ApoE KO. We further treated the P301S/ApoE4 mice with the LXR agonist GW3965 to test if promoting cholesterol efflux in P301S mice would reduce tau pathology and neurodegeneration in this model.ResultsBy performing unbiased lipidomic analysis of forebrain samples, we demonstrate that P301S/ApoE KI mice accumulate significant amounts of specific cholesteryl esters, oxidized sterols and endolysosomal BMP lipids in an ApoE‐isoform and Tau‐dependent manner. We further show that microglia from aged 9.5 months old P301S/ApoE4 mice accumulate significant amounts of neutral BODIPY‐positive lipid inclusions within lysosomes. Next, we demonstrate that the oral administration of the LXR agonist GW3965 for 3 months significantly reduces p‐tau‐positive AT8 immunostaining in cortex and hippocampus, protects from associated brain neurodegeneration, and improves nesting behavior in 9.5 months old P301S/ApoE4 mice. Using bulk RNA sequencing and immunostaining, we show that LXR agonist diet induces changes in cholesterol biosynthesis and metabolism that result in a significant reduction of neuroinflammatory responses in aged P301S/ApoE4 mice. Lastly, using unbiased lipidomics of forebrain tissues we demonstrate that P301S/ApoE4 mice on LXR diet exhibit significantly lower levels of cholesterol esters when compared to tau transgenic animals on control diet.ConclusionsTogether, we demonstrate that ApoE4 promotes lipid accumulation in glia in the setting of tauopathy and that reducing the accumulation of these lipids by LXR activation is neuroprotective.

Correlational analysis of plasma metabolome and brain imaging in a humanized APOE mouse model

AbstractBackgroundApolipoprotein E (APOE) ε4 is the strongest genetic risk factor for the development of late‐onset Alzheimer’s disease (LOAD). Additionally, females have a 2x greater risk of developing LOAD than males. LOAD patients show brain glucose hypometabolism and severe reduction in hippocampal volume. Hippocampal atrophy has also been linked with plasma ceramide and phosphotidylcholine (PC) levels in these patients. This study explores the effects of sex and genotype on the plasma metabolome and potential correlations to brain imaging metrics in an aged humanized APOE (hAPOE) mouse model.MethodPlasma samples from 23–25‐month‐old hAPOE mice (37M/32F) expressing ε3/3, ε3/4 or ε4/4 genotypes were analyzed via mass spectrometry using the Biocrates MxP® Quant 500 platform. In a subset of these animals (24M/20F), in‐vivo FDG‐PET and high‐resolution ex‐vivo MRI were obtained. Cerebral FDG‐PET standardized uptake values were normalized to cerebellum (SUVr). Cerebral SUVr and regional volumes were correlated with detected metabolites and metabolic indicators using Pearson correlations. Two‐way ANOVAs were used to identify sex and genotype effects with post‐hoc t‐tests to determine statistical significance.ResulthAPOE ε3/3 mice had significantly greater cholesteryl ester (54%; p < 0.026) and lysophosphotidylcholine (lysoPC; 27%; p < 0.031) levels compared to ε4/4 mice. Females had lower levels of PCs (93%; p < 0.007), lysoPCs (82%; p < 0.018), triglycerides (62%; p < 0.045), and 1‐Met‐His (p = 5.84E‐25) than males. Significant positive correlations were observed between cerebral SUVr and PCs (45%; p < 0.049) as well as lysoPCs (82%; p <0.017). Total brain volume was negatively correlated with plasma 3‐Met‐His:creatinine ratio, indicative of muscle protein degradation (r = ‐0.44; p = 0.003) and positively correlated with (LysoPC+ arachidonic acid): PC ratio, indicative of phospholipase A2 activity (r = 0.42; p = 0.004). Right hippocampal volume percentage was significantly positively correlated with PCs (64%; p < 0.045) and 1‐Met‐His (p = 0.00067).ConclusionAt a comparable human age of ∼ 70 years, within the humanized APOE mouse, sex was the major contributing factor to metabolic differences in peripheral blood plasma. Levels of peripheral metabolites correlated with brain volumetrics and glucose metabolism, highlighting potential therapeutic targets for interventions designed to preserve neuronal health in AD.

Solanaceae Glycoalkaloids Disturb Lipid Metabolism in the Tenebrio molitor Beetle.

Glycoalkaloids (GAs) are produced naturally by plants and affect insect survivability and fertility. These compounds can be considered potential bioinsecticides; however, the mechanisms and effects of their action remain undiscovered. As lipids are essential molecules for the proper functioning of an insect organism, this research aimed to determine the effects of GAs on the lipid metabolism of the Tenebrio molitor beetle. Solanine, chaconine, tomatine, and tomato leaf extract were applied to larvae by injection at two concentrations, 10-8 and 10-5 M. Then, the tissue was isolated after 2 and 24 h to determine the levels of free fatty acids, sterols and esters using the GC-MS technique. Moreover, the triacylglyceride level and the activity of the key β-oxidation enzyme, 3-hydroxyacyl-CoA dehydrogenase (HADH), were measured. The results indicate that GAs affect the content and composition of lipid compounds in the beetles' haemolymph and fat body. The effects depend on the GA concentrations, incubation time, and kind of tissue. Moreover, the tested compounds decrease HADH activity, especially in the fat body, which may affect energy production. To our knowledge, this is the first study concerning lipid metabolism in T. molitor after GA application. Our results provide some insights into that topic.

Lipases and carboxylesterases affect moth sex pheromone compounds involved in interspecific mate recognition

Moth sex pheromones are a classical model for studying sexual selection. Females typically produce a species-specific pheromone blend that attracts males. Revealing the enzymes involved in the interspecific variation in blend composition is key for understanding the evolution of these sexual communication systems. The nature of the enzymes involved in the variation of acetate esters, which are prominent compounds in moth pheromone blends, remains unclear. We identify enzymes involved in acetate degradation using two closely related moth species: Heliothis (Chloridea) subflexa and H. (C.) virescens, which have different quantities of acetate esters in their sex pheromone. Through comparative transcriptomic analyses and CRISPR/Cas9 knockouts, we show that two lipases and two esterases from H. virescens reduce the levels of pheromone acetate esters when expressed in H. subflexa females. Together, our results show that lipases and carboxylesterases are involved in tuning Lepidoptera pheromones composition.

Circulating metabolites may illustrate relationship of alcohol consumption with cardiovascular disease

BackgroundMetabolite signatures of long-term alcohol consumption are lacking. To better understand the molecular basis linking alcohol drinking and cardiovascular disease (CVD), we investigated circulating metabolites associated with long-term alcohol consumption and examined whether these metabolites were associated with incident CVD.MethodsCumulative average alcohol consumption (g/day) was derived from the total consumption of beer, wine, and liquor on average of 19 years in 2428 Framingham Heart Study Offspring participants (mean age 56 years, 52% women). We used linear mixed models to investigate the associations of alcohol consumption with 211 log-transformed plasma metabolites, adjusting for age, sex, batch, smoking, diet, physical activity, BMI, and familial relationship. Cox models were used to test the association of alcohol-related metabolite scores with fatal and nonfatal incident CVD (myocardial infarction, coronary heart disease, stroke, and heart failure).ResultsWe identified 60 metabolites associated with cumulative average alcohol consumption (p < 0.05/211 ≈ 0.00024). For example, 1 g/day increase of alcohol consumption was associated with higher levels of cholesteryl esters (e.g., CE 16:1, beta = 0.023 ± 0.002, p = 6.3e − 45) and phosphatidylcholine (e.g., PC 32:1, beta = 0.021 ± 0.002, p = 3.1e − 38). Survival analysis identified that 10 alcohol-associated metabolites were also associated with a differential CVD risk after adjusting for age, sex, and batch. Further, we built two alcohol consumption weighted metabolite scores using these 10 metabolites and showed that, with adjustment age, sex, batch, and common CVD risk factors, the two scores had comparable but opposite associations with incident CVD, hazard ratio 1.11 (95% CI = [1.02, 1.21], p = 0.02) vs 0.88 (95% CI = [0.78, 0.98], p = 0.02).ConclusionsWe identified 60 long-term alcohol consumption-associated metabolites. The association analysis with incident CVD suggests a complex metabolic basis between alcohol consumption and CVD.

Modulation of the Aromatic Profile of Verdejo Wine through Sequential Inoculation of Wickerhamomyces anomalus and Saccharomyces cerevisiae

Two strains of Saccharomyces cerevisiae (Sc01 and Sc02) and one strain of Wickerhamomyces anomalus (Wa) were isolated from organic Verdejo spontaneous fermentations and used for the development of experimental winemaking. Sc01 and Sc02 represented 52.7% of the population of the Saccharomyces strains isolated throughout the fermentation process. W. anomalus appeared as the predominant species among the non-Saccharomyces yeasts. Wa turned out to be the strain of this species with the shortest lag phase and positive enzymatic activities, and it was selected for white wine production. Fermentations with unique inoculation of S. cerevisiae strains were compared with sequential inoculation with W. anomalus. The results showed that the sequential inoculations did not affect the fermentation kinetics or physicochemical characteristics of the wines compared with the unique inoculations. However, this study identified a significant impact on the aromatic profiles of the produced wines due to the sequential inoculations. This modification resulted in a similar new aromatic profile in both sequential inoculations, demonstrating common characteristics related to the contribution of W. anomalus. In general, the sequential fermentations were mainly characterized by lower levels of acetate esters and an increase in ethyl acetate levels, whereas lower levels of ethyl octanoate and ethyl dec-9-enoate were detected. Propan-1-ol and butan-1-ol showed an increase in the sequential fermentations, while 4-methylpentan-1-ol and 2-phenylethanol were found in lower concentrations. These results highlight the great influence that the presence of specific strains of native non-Saccharomyces yeasts exerts on the characteristics of elaborate wines.

Evolution behavior of volatile components of shiitake mushrooms during infrared-assisted spouted bed drying

The present study aimed to investigate the effect of different drying temperatures and airflow speeds on the number and species of volatile components in infrared-assisted spouted bed dried (IRSBD) Shiitake mushrooms. The dynamics changes in volatile components (determined by HS-SPME-GC-MS) during drying under optimal conditions were also monitored. Results revealed that the maximum number of volatile components (69 species) was observed at a temperature of 55 °C and airflow speed of 8.0 m/s, of which the volatile components in Shiitake mushrooms varied significantly over the drying process at this condition. Fresh Shiitake mushrooms mainly composed of volatile substances such as alcohols, ketones and acids. During the early drying stage (0–40 min), the levels of alcohols and ketones gradually decreased, while the species and levels of aldehydes, esters, and volatile sulfur-containing compounds (VSCs) increased. In the middle stage (40–120 min), levels of alcohols, esters, aldehydes, acids, and alkanes species increased, while the levels of VSCs decreased. For the last stage (120–200 min), the levels of sulfur-containing heterocyclic compounds, aldehydes, esters, acids, pyrazines, and alkanes were all increased. The findings of this study provide insights into the flavor formation mechanism during IRSBD of Shiitake mushrooms and offer a theoretical reference for the production of industrial flavorful dried goods.

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.

Impact of cluster thinning and harvest date on berry volatile composition and sensory profile of &lt;i&gt;Vitis&lt;/i&gt; sp. Seyval blanc and Vandal-Cliche

Northern conditions are challenging for grape and wine producers. To cope with these challenges, the use of early ripening interspecific hybrid Vitis sp., such as Seyval blanc and Vandal-Cliche, is often preferred to traditional V. vinifera. However, knowledge about cultural practices suitable for interspecific hybrid varieties are still scarce, especially regarding their impact on profiles of volatile compounds and the sensory perception of berries. In this study, the impact of cluster thinning and harvest date on grapevine physiology, must chemical composition and berry sensory attributes of Seyval blanc and Vandal-Cliche was investigated. Three crop loads (100 %, 70 % and 40 % crop) and three harvest dates corresponding to pre-maturity, maturity, and post-maturity were assessed in 2012 and 2013. Cluster thinning significantly decreased the yield of Vandal-Cliche, but not of Seyval blanc, for which it instead improved fruit set without affecting yield. The impact of cluster thinning on must chemical composition was limited for both cultivars, although some significant changes were observed, especially in the cool season of 2013. Clear variations during ripening, in terms of technological parameters and aroma characteristics, were observed depending on the cultivars and the seasons. In Seyval blanc, C6-alcohols and C13-norisoprenoids decreased during ripening, while C6-aldehydes and linalool increased. In Vandal-Cliche, berries from the first and the last sampling dates of the warm season of 2012 showed the highest levels of C13-norisoprenoids, whereas berries from the last sampling date in the cold season of 2013 showed the highest levels of terpenes, C13-norisoprenoids and ethyl esters. Despite its limited impact on fruit chemical composition, cluster thinning significantly impacted the sensory perception of Vandal-Cliche berries in both years. Cluster-thinned berries had softer skin, sweeter and less acidic pulp, and fruitier skin and pulp aroma. Skin softness allowed excellent discrimination of the maturity of both cultivars during the two study years, suggesting that this descriptor could be a suitable maturity marker for these interspecific hybrid varieties. In summary, cluster thinning proves beneficial for enhancing fruit set in Seyval Blanc in a northern climate; however, its influence on fruit quality is minimal for both cultivars.

Human blood lipid profiles after dietary supplementation of different omega 3 ethyl esters formulations

The validity of omega 3 fatty acids (ω3 FAs), mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), as dietary supplements has been widely proved. It’s well known in fact, that they protect against cardiovascular diseases, reduce the levels of triacylglycerides (TAGs) and cholesteryl esters (CEs) in blood, and have anti-inflammatory activity. For these reasons, in the last few years the production of dietary supplement containing ω3 has increased significantly. In this context, the possibility to obtain ω3 and other high value molecules from alternative sources as fish waste, in accordance with the principles of circular economy, becomes an enormous attractive. In addition, the opportunity of creating new products, with greater health benefits, represents an interesting challenge. The current study was focused on the extraction of ω3 fatty acids and peptides from tuna waste industry, to realize a new dietary supplement. To this purpose, a supercritical fluid extraction (SFE) method was developed to separate, isolate, and enrich the different fractions subsequently used to produce an innovative formulate. The obtained supplement was characterized in terms of fatty acids esterified ester (FAEE) composition by gas chromatography (GC) coupled to both flame ionization detection (FID) and mass spectrometry (MS), and content of heavy metals by inductively coupled plasma–mass spectrometry (ICP-MS).The effects of ω3 supplementation on metabolism and circulating lipid profiles was tested on 12 volunteers and assessed by GC-FID analysis of whole blood collected on paper support (Dried Blood Spot, DBS) at the beginning of the study and after thirty days. The results of plasma fatty acids levels after 30 days showed a significant decrease in the ω6/ω3 ratio, as well as the saturated/polyunsaturated fatty acids (SFA/PUFA) ratio, compared to subjects who took the ω3 ethyl esters unformulated. The novel formulated supplements proved to be extremely interesting and promising products, due to a significant increase in bioavailability, that makes it highly competitive in the current panorama of the nutraceutical industry.

The effect of commercial β-glucosidase and its immobilization on quality of red wine production

To find a feasible strategy for commercial β-glucosidase to enhance red wine quality, immobilized enzyme technology were considered. The preferred epoxy resin using the covalent binding method was ES-103B, and its optimal immobilization conditions were pH 4.9, 25 h immobilization time and 3 mg/g enzyme concentration. Meanwhile, this immobilized β-glucosidase still contained weak esterase activity just like commercial β-glucosidase. Free commercial β-glucosidase had different effects on the fermentation of 11 clones from three grape varieties (Syrah, Merlot and Cabernet Sauvignon) to produce wine. For example, the free enzyme increased the concentrations of β-damascenone, 1-hexanol, phenylethyl alcohol, and three ethyl esters (ethyl hexanoate, ethyl octanoate and ethyl decanoate) in a Cabernet Sauvignon (CS169) wine, but total anthocyanins level was reduced, affecting the color depth (a* value). Notably, during the alcoholic fermentation stage of CS169, immobilized β-glucosidase did not significantly decrease polyphenolic levels and color depth (a* value). What's more, using immobilized β-glucosidase under this treatment condition resulted in the highest levels of higher alcohols, ethyl esters, and acetate. Moreover, β-damascenone content increased by more than 25.35%, as well as phenethyl alcohol and benzaldehyde of benzenic compounds significantly increased by over 72.23% and two-fold, respectively. As a result, CS169 wine possessed more complex aroma and highest sensory score. Therefore, enologists can use immobilized β-glucosidase to develop various strategies that enhance wine quality and produce different wine styles.

Impact of Different Drying Methods on the Microbiota, Volatilome, Color, and Sensory Traits of Sea Fennel (Crithmum maritimum L.) Leaves.

Sea fennel (Crithmum maritimum L.) is a strongly aromatic herb of the Apiaceae family, whose full exploitation by the modern food industry is of growing interest. This study aimed at investigating the microbiological quality, volatile profile, and sensory traits of sea fennel spices produced using room-temperature drying, oven drying, microwave drying, and freeze drying. All the assayed methods were able to remove moisture up until water activity values below 0.6 were reached; however, except for microwave drying, none of the assayed methods were effective in reducing the loads of contaminating microorganisms. The metataxonomic analysis highlighted the presence of phytopathogens and even human pathogens, including members of the genera Bacillus, Pseudomonas, Alternaria, and Cryptococcus. When compared to fresh leaves, dried leaves showed increased L* (lightness) and c* (chroma, saturation) values and reduced hue angle. Dried leaves were also characterized by decreased levels of terpene hydrocarbons and increased levels of aldehydes, alcohols, and esters. For the sensory test, the microwave-dried samples obtained the highest appreciation by the trained panel. Overall, the collected data indicated microwave drying as the best option for producing sea fennel spices with low microbial loads, brilliant green color, and high-quality sensory traits.

A lipidomic approach to bisphenol F-induced non-alcoholic fatty liver disease-like changes: altered lipid components in a murine model.

Bisphenol A (BPA), a typical environmental endocrine disruptor, is an "obesogen" that can induce lipid accumulation in the liver. Highly similar in structure to BPA, bisphenol F (BPF) is becoming the dominant BPA substitute on the market, which attracts more and more attention due to its potential adverse effects. Recently, BPF exposure is found to cause non-alcoholic fatty liver disease (NAFLD)-like changes; however, the underlying toxic effects remain poorly understood. Therefore, in the current study, we focused on BPF-mediated lipid homeostasis, especially the alterations of lipid components and metabolism. In human serum, the BPF levels in healthy controls and NAFLD patients were assessed by ELISA, and BPF-induced disturbance of lipid metabolism was evaluated in mouse model via non-targeted lipomic methods with ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry. It suggested that BPF exposure was positively correlated with NAFLD severity and triglyceride level in patients. Based on the relationships, lipid metabolites were assessed in mouse livers between control and BPF-treated group, and it revealed that twenty-six lipid metabolites (including phospholipids, sphingolipids, and glycerides) were significantly changed in mouse livers. Phosphatidylcholine, phosphatidylethanolamine, and diglyceryl ester levels were lower than those in the control mice; hexose ceramide content in sphingolipids markedly increased in BPF-treated mouse livers. Noteworthily, the glycerophospholipid metabolic pathway was found to be the most pronounced in BPF-induced disturbance of lipid metabolism. Therefore, the current study, for the first time, is deciphering the BPF-induced lipid metabolic disturbance, which may provide novel intervention strategies for BPF-induced NAFLD-like changes.

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

Analysis for different flavor compounds in mature milk from human and livestock animals by GC×GC-TOFMS.

Breast milk plays a crucial role in the taste development of infants, which cannot be replicated by other mammalian milk or formulas. This study aimed to identify and characterize the flavor substances in 15 different types of milk and analyze the differences among them. The results showed that human milk contained high levels of esters, particularly fatty acid ethyl esters, which contribute to its unique flavor. The four substances that had the highest flavor contribution in all species were identified as 2,3-butanedione, trimethylamine, isophorone, and acetaldehyde. Furthermore, the analysis of differences revealed that thermal-oxidation of lipids could explain the variation between human milk and other species in terms of flavor compounds. The key differential flavor compounds identified in milk from all species were trimethylamine, propanal, 1-pentanol, pyridine 2-methyl, and 2-butanone. These findings can potentially aid in developing formulas that better meet the taste needs of infants.

서리피해를 받은 잎으로 만든 홍차의 GC×GC-TOFMS 휘발성 화합물 분석

Korea suffers from unusual droughts, heavy rain, or high temperatures due to the abnormal weather phenomenon worldwide. This climate change directly impacts the occurrence of frost in spring, which is causing serious damage to the buds and leaves of tea plants that mainly grow in spring. Frost damage delays the harvest time and decreases production, leading to a decline in the income of tea-producing farmers. Therefore, it is essential to develop ways of using discarded tea leaves. This study analyzed the volatile compounds in black tea prepared from the discarded tea leaves by two-dimensional gas chromatography-time of flight mass spectrometry (GC×GC-TOFMS). The total relative content of 481 compounds was approximately 1.8 times higher in frost-damaged black tea than in regular black tea. The ketone and ester levels in frost-damaged black tea were approximately twice as high as that in normal black tea. Two types of black tea samples were well distinguished by a dependable PLS-DA model, which presented satisfied variance and cross-validated predictive capability (R2Y=0.997, Q2=0.956) without overfitting phenomena (R2=0.953, Q2=-0.266). One hundred eighty compounds with variable importance in the projection (VIP) values &gt;1.0 were applied. The result of HCA analysis, esters, and alkenes were concentrated in normal black tea, and the ketones and heterocyclic compounds were concentrated in frost-damaged black tea. These results provide basic data for improving the process of producing good products using discarded leaves caused by frost damage.

Plasma lipidome reveals susceptibility and resistance of Pekin ducks to DHAV-3

Duck hepatitis A virus genotype 3 (DHAV-3) is the most popular pathogen of duck viral hepatitis (DVH) and has led to a huge economic threat to the Asian duck industry. In this work, we investigated the differences in the LC-MS/MS-based dynamic lipid profiles between susceptible and resistant Pekin duck lines with DHAV-3 infection. We found that the plasma lipidome of the two duck lines was characterized differently in expression levels of lipids during the infection, such as decreased levels of glycerolipids and increased levels of cholesteryl esters and glycerophospholipids in susceptible ducks compared with resistant ducks. By integrating lipidomics and transcriptomics analysis, we showed that the altered homeostasis of lipids was potentially regulated by a variety of differentially expressed genes including CHPT1, PI4K2A, and OSBP2 between the two duck lines, which could account for liver dysfunction, apoptosis, and illness upon DHAV-3 infection. Using the least absolute shrinkage and selection operator (LASSO) approach, we determined a total of 25 infection-related lipids that were able to distinguish between the infection states of susceptible and resistant ducks. This study provides molecular clues for elucidating the pathogenesis and therapeutic strategies of DHAV-3 infection in ducklings, which has implication for the development of resistance breeding.

Identification of volatile organic compounds as markers to detect Monilinia fructicola infection in fresh peaches

Monilinia spp. are among the main fungal pathogen affecting peaches, and they can cause severe pre- and postharvest losses. Development of smart packaging technologies (e.g., volatile indicators), facilitating infection detection and preventing other fruit from being contaminated, is still limited. In this study, we compared for the first time the aroma profile of whole healthy fresh peaches to Monilinia fructicola-artificially inoculated peaches, identifying discriminant volatile organic compounds (VOCs). More than one hundred VOCs were detected by applying head space solid-phase microextraction followed by GC-MS analysis. The level of methyl esters, hydrocarbons, lactones, and acids decreased in infected peaches indicating fruit aroma deterioration, while the concentration of ethyl esters and alcohols increased. In particular, the amount of ethanol and derived ethyl acetate reached a maximum of 24- and 20-fold increase in the infected peaches, respectively. Isobutanol, propyl acetate, and ethyl isovalerate were specifically emitted by M. fructicola-infected peaches. These compounds might serve as markers for the development of smart sensors allowing the detection of fungal infection.

Cholesterol biogenesis is a PTEN-dependent actionable node for the treatment of endocrine therapy-refractory cancers.

PTEN and PIK3CA mutations are the most prevalent PI3K pathway alterations in prostate, breast, colorectal, and endometrial cancers. p110β becomes the prominent PI3K isoform upon PTEN loss. In this study, we aimed to understand the molecular mechanisms of PI3K dependence in the absence of PTEN. Using online bioinformatical tools, we examined two publicly available microarray datasets with aberrant PI3K activation. We found that the rate-limiting enzyme of cholesterol biogenesis, SQLE, was significantly upregulated in p110β-hyperactivated or PTEN-deficient mouse prostate tumors. Concomitantly, the expression of cholesterol biosynthesis pathway enzymes was directly correlated with PI3K activation status in microarray datasets and diminished upon PTEN re-expression in PTEN-null prostate cancer cells. Particularly, PTEN re-expression decreased SQLE protein levels in PTEN-deficient prostate cancer cells. We performed targeted metabolomics and detected reduced levels of cholesteryl esters as well as free cholesterol upon PTEN re-expression. Notably, PTEN-null prostate and breast cancer cell lines were more sensitive to pharmacological intervention with the cholesterol pathway than PTEN-replete cancer cells. Since steroid hormones use sterols as structural precursors, we studied whether cholesterol biosynthesis may be a metabolic vulnerability that enhances antihormone therapy in PTEN-null castration-resistant prostate cancer cells. Coinhibition of cholesterol biosynthesis and the androgen receptor enhanced their sensitivity. Moreover, PTEN suppression in endocrine therapy-resistant luminal-A breast cancer cells leads to an increase in SQLE expression and a corresponding sensitization to the inhibition of cholesterol synthesis. According to our data, targeting cholesterol biosynthesis in combination with the hormone receptor signaling axis can potentially treat hormone-resistant prostate and breast cancers.