Distribution Of Lipids Research Articles

Development of a Desorption Electrospray Ionization-Multiple-Reaction-Monitoring Mass Spectrometry (DESI-MRM) Workflow for Spatially Mapping Oxylipins in Pulmonary Tissue.

Oxylipins are a class of low-abundance lipids formed via oxygenation of fatty acids. These compounds include potent signaling molecules (e.g., octadecanoids, eicosanoids) that can exert essential functions in the pathophysiology of inflammatory diseases including asthma. While some oxylipin signaling cascades have been unraveled using LC-MS/MS-based methods, measurements in homogenate samples do not represent the spatial heterogeneity of lipid metabolism. Mass spectrometry imaging (MSI) directly detects analytes from a surface, which enables spatial mapping of oxylipin biosynthesis and migration within the tissue. MSI has lacked the sensitivity to routinely detect low-abundance oxylipins; however, new multiple-reaction-monitoring (MRM)-based MSI technologies show increased sensitivity. In this study, we developed a workflow to apply desorption electrospray ionization coupled to a triple quadrupole mass spectrometer (DESI-MRM) to spatially map oxylipins in pulmonary tissue. The targeted MSI workflow screened guinea pig lung extracts using LC-MS/MS to filter oxylipin targets based on their detectability by DESI-MRM. A panel of 5 oxylipins was then selected for DESI-MRM imaging derived from arachidonic acid (TXB2, 11-HETE, 12-HETE), linoleic acid (12,13-DiHOME), and α-linolenic acid (16-HOTrE). To parse this new data type, a custom-built R package (quantMSImageR) was developed with functionality to label regions of interest as well as quantify and analyze lipid distributions. The spatial distributions quantified by DESI-MRM were supported by LC-MS/MS analysis, with both indicating that 16-HOTrE and 12-HETE were associated with airways, while 12,13-DiHOME and arachidonic acid were mapped to parenchyma. This study realizes the potential of targeted MSI to routinely map low-abundance oxylipins with high specificity at scale.

Dichlorvos evokes systemic lipid dysmetabolism in Wistar rats: rescindment influence of curcumin

Organophosphorus pesticides such as dichlorvos (DDVP) are often employed to eradicate pests, especially in low and medium-income countries. However, they have several negative impacts on the visceral organs. Astonishingly, curcumin protects organs from the detrimental effects of xenobiotics via the maintenance of redox homeostasis; unfortunately, its role in dichlorvos-provoked multi-organ impairment vis-à-vis lipid homeostasis has not been examined. Therefore, this undertaking probed the remedial efficacy of curcumin on DDVP-prompted combined systemic toxicity and major lipid distribution. Randomization was engaged to dedicate rats (40) into seven groups (6 rats/group): control, DDVP only (20 mg kg-1day-1), DDVP administered with either curcumin (50 and 100 mg kg-1day-1) or reference medication atropine (0.2 mg kg-1day-1), and curcumin only (50 and 100 mg kg-1day-1). DDVP was dispensed orally for one week, followed by two weeks of curcumin treatment. Twenty-four hours after the last administration, we sacrificed the rats and collected their blood and viscera (liver, kidney, heart, lung, and brain) for bioassays. Curcumin remarkably (p<0.05) rescinded DDVP-mediated increases in plasma, LDL, and systemic cholesterol; markedly (p<0.05) attenuated DDVP-elicited decreases in HDL-cholesterol and TAG contents in all the compartments except erythrocyte and liver; and significantly (p<0.05) abated DDVP-induced plasma phospholipidaemia, multi-organ phospholipidosis, and up-regulation of 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA-R) activity. This finding demonstrated that curcumin reverses DDVP-triggered anomalous lipid dynamics by abating cholesterogenesis and phospholipidosis and restoring HMG-CoA-R activity.

Synergistically Activated Aggregation-Induced Emission Probe for Precise In Situ Staining of Lipids in Atherosclerotic Plaques.

Visualizing the localization and distribution of lipids within arteries is crucial for studying atherosclerosis. However, existing lipid-specific probes face challenges such as strong hydrophobicity and nonspecific staining of lipophilic organelles or tissues, making them impractical for the precise identification of atherosclerotic plaques. To address this issue, we design a synergistically activated probe, Cbz-Lys-Lys-TPEB, which responds to cathepsin B (CTB) and H2O2 for the in situ generation of aggregation-induced emission luminogens (AIEgens). This enables specific staining of lipids within arteries and precise imaging of atherosclerotic plaques. The probe combines a tetraphenylethene building block with a hydrophilic peptide sequence (Cbz-Lys-Lys) and phenylboric acid module, providing excellent water solubility and fluorescence quenching in a molecular dispersion state. Upon interaction with H2O2 and CTB within plaques, the hydrophilic Cbz-Lys-Lys-TPEB probe is specifically cleaved and converted into hydrophobic AIEgens, leading to rapid aggregation and significant fluorescence enhancement. Interestingly, the in situ-liberated AIEgens display distinct lipid binding ability, effectively tracking the location and distribution of lipids in plaques. This synergistic target-activated AIEgen liberation strategy demonstrates significant feasibility for the reliable and accurate identification of atherosclerotic plaques, holding tremendous potential for clinical diagnosis and risk stratification of atherosclerosis.

Shape Analysis of Biomimetic and Plasma Membrane Vesicles

Giant membrane vesicles (GUVs) and Giant plasma membrane vesicles (GPMVs) are used as models to study membrane properties. We conducted a comparative study to examine how reducing the volume of vesicles with different lipid compositions, solution symmetries, solution asymmetries, and membrane charges affects their morphology. We used three‐dimensional visualization techniques to study the shape of the vesicles. Although the vesicles may not be perfectly spherical, they exhibit some fluctuations in their shape. To understand these variations, we used confocal image stacks for visualization. Our experimental observations show that the membrane's charge influences the deflation of the GUVs in the presence of trans‐bilayer sugar asymmetries. The lipid bilayers of our GUVs have a uniform distribution of lipids in both leaflets, indicating no asymmetry in lipid composition. However, we induce trans‐bilayer asymmetries by exposing each leaflet to different solution compositions, leading to asymmetric adsorption or desorption layers. We also estimated and compared the deformation of GPMV shapes extracted from cells with trans‐bilayer buffer asymmetries and composition asymmetries with biomimetic membranes.

Membrane structure-responsive lipid scrambling by TMEM63B to control plasma membrane lipid distribution.

Phospholipids are asymmetrically distributed in the plasma membrane (PM), with phosphatidylcholine and sphingomyelin abundant in the outer leaflet. However, the mechanisms by which their distribution is regulated remain unclear. Here, we show that transmembrane protein 63B (TMEM63B) functions as a membrane structure-responsive lipid scramblase localized at the PM and lysosomes, activating bidirectional lipid translocation upon changes in membrane curvature and thickness. TMEM63B contains two intracellular loops with palmitoylated cysteine residue clusters essential for its scrambling function. TMEM63B deficiency alters phosphatidylcholine and sphingomyelin distributions in the PM. Persons with heterozygous mutations in TMEM63B are known to develop neurodevelopmental disorders. We show that V44M, the most frequent substitution, confers constitutive scramblase activity on TMEM63B, disrupting PM phospholipid asymmetry. We determined the cryo-electron microscopy structures of TMEM63B in its open and closed conformations, uncovering a lipid translocation pathway formed in response to changes in the membrane environment. Together, our results identify TMEM63B as a membrane structure-responsive scramblase that controls PM lipid distribution and we reveal the molecular basis for lipid scrambling and its biological importance.

Simultaneous Determination of the Position and Cis-Trans Configuration of Lipid C═C Bonds via Asymmetric Derivatization and Ion Mobility-Mass Spectrometry.

The position and cis-trans configuration of C═C bonds in unsaturated lipids significantly affect their biological activities. Simultaneous identification of the position and cis-trans configuration of C═C bonds in unsaturated lipids is important; nonetheless, it still remains a challenging task. Herein, a stereoselective asymmetric reaction was used to recognize cis-trans isomers of the C═C bonds, and the derivatized precursor ions and product ions were subjected to tandem ion mobility-mass spectrometry (IM-MS) analysis. The theoretical calculation revealed that the formation of intramolecular hydrogen bonds after the cyclization reaction amplified the structural difference between diastereomers and increased the separation efficiency in IM. Consequently, a simple, sensitive, and highly selective platform for simultaneous determination of the position and cis-trans configuration of various C═C bonds in unsaturated lipids was established. It was then successfully applied to pinpoint the cis-trans geometry conversion of the located C═C bonds in lipids of the bacterial membrane under environmental stress and track the heterogeneous distribution of unsaturated lipids in rats after spinal cord injury. The present study also offers new insights into the application of IM-MS technology in resolving molecular structures and demonstrates the potential as a platform for a broad range of applications.

Comparison of low-density lipoprotein cholesterol (LDL-c) estimates by in-lab and point-of-care devices in the context of emerging LDL-c equations

Abstract Low-density lipoprotein cholesterol (LDL-c) and lipid measurements are used for hyperlipidemia diagnosis, cardiovascular disease risk classification, and medication management. Millions of lipid panels are performed annually. Given the widespread need for lipid testing, there are two CLIA-waived point-of-care (POC) lipid testing devices. These devices were FDA-approved using the Friedewald equation to estimate LDL-c based on measurements of (triglycerides (TG), high-density lipoprotein cholesterol (HDL-c), and total cholesterol (TC). By contrast, for laboratory-based LDL-c estimation, the Friedewald equation is being replaced by newer, more accurate equations such as the NIH-Sampson equation. These equations use the same lipid panel results to estimate LDL-c and only differ in the arithmetic of the estimation. This study evaluates how differences between the in-clinic POC machines and in-laboratory lipid measurements affect the estimated LDL-c results and are compounded by differences in the equations used for LDL-c estimation. This retrospective observational study collected deidentified lipid results (TG, HDL-c, TC, LDL-c) and demographic data (age, gender) for all samples that had lipid panel results from in-lab and POC within twenty-four hours of each other in a single hospital system between 2014 and 2023. Three hundred twenty samples were identified; samples with non-numerical values or results outside of the reportable range for TG, HDL-c, or TC were not included in subsequent LDL-c calculations using the Friedewald and NIH-Sampson equations (69 results). Patients under the age of 18 were excluded (2 results). Two hundred and forty-nine samples met inclusion criteria; this cohort showed non-significant differences in lipid, age, and gender distributions relative to all POC results tested in the same time frame. Consistent with prior reports, we observed discordance between POC and the in-lab lipid measurements, particularly for TG (Bland-Altman: bias:-23.04 mg/dL, standard deviation:61.3 mg/dL). These analytical differences may not change clinical management if the cardiovascular risk classification using estimated LDL-c is unchanged. However, the risk classification based on the in-lab versus in-clinic testing differed for 20% of patients. The most pronounced difference in LDL-c estimation occurred when the POC machine used Friedewald and in-lab testing used NIH-Sampson, and resulted in 5% more patients differentially classified. Regardless of testing platform, more patients are categorized as higher risk on an individual and population-based level with the NIH-Sampson equation. This study highlights the need for transparency in lipid panel reports regarding which LDL-c equation is used in both POC and in-lab testing formats, and the need for readily available tools for conversion between different LDL-c estimation equations.

Lipid droplet distribution in Atlantic salmon (Salmo salar L.) oocytes is related to the fertilisation and developmental outcome

At present, there is no simple and practical applicable method to determine the quality of Atlantic salmon oocytes upon collection at the fish farm. Investigating oocyte lipid droplet patterns might be a tool for the aquaculture industry to predict oocyte quality in Atlantic salmon. While examining the lipid distribution in oocyte batches from 16 females of Atlantic salmon with a range in fertilisation rate (6–97 %), five categories of lipid droplet patterns were distinguished. In category 1, the lipid droplets were evenly distributed whereas in the remaining categories lipid droplets showed varying degree of coalescence. Categories 2, 3, 4 and 5 were distinguished based on the area of coalesced lipid droplets. The fertilisation rate was observed to be high (≥ 90 %), in females that had more oocytes from category 1, 2 and 3 whereas females with more oocytes from category 4 and 5 showed a low fertilisation rate (<90 %). A similar pattern was revealed between lipid droplet categories and eyed embryo and hatching success. Staining of salmon oocytes further confirmed the observed lipid droplet patterns, and different sizes of lipid droplets were present in almost all oocytes. The study revealed a significant association between lipid droplet category and fertilisation outcome in oocytes of Atlantic salmon that can be a practical tool for predicting oocyte quality.

Erythrocyte membrane and breast milk fatty acid profile in lactating mothers: relationship with infant erythrocyte membrane fatty acid profile.

During the first thousand days of life, fetus and infant's nutrition depends on mother's diet. Polyunsaturated fatty acids(PUFA) are important substrates in infant neurogenesis. We related erythrocyte membrane (EM) and breast milk fatty acids (FA) profile in lactating mothers with the EM FA profile in exclusively breastfed infants and evaluated maternal fat consumption. We conducted an observational, cross-sectional analytical study. During the 2016-2019 period, milk and blood samples from adult mothers 90 days post-partum and infant's blood were analysed, and FA were determined by GC. A frequency of consumption survey of fatty acids precursor foods and sources was conducted. The sample included forty-five mother-infant EM and forty-five milk samples donated by the same mothers. A low percentage of DHA (0·14 (0·12-0·2)) was found in milk, consistent with mother's low consumption of DHA-rich foods. A significant positive correlation between infant's EM DHA percentage and milk DHA percentage (r = 0·39; P value 0·008), as well as between infant's EM ω-3 fatty acids sum and milk DHA percentage (r = 0·39; P value 0·008), was found. When milk had a DHA percentage greater than or equal to 0·20 %, infants had a significant increase in DHA in their EM. Mother's consumption of DHA precursors and sources was NS. The relation between the DHA percentage distribution found in maternal milk, and the DHA percentage distribution found in infant's and mother's EM was proven in this population. Dietary fatty acid intake is associated with the maternal milk lipid distribution and with mothers' and infant's EM fatty acids percentage.

Maternal Lipids in Pregnancy and Later Life Dyslipidemia: The POUCHmoms Longitudinal Cohort Study.

Maternal lipid levels increase in normal pregnancies. Here, we examine whether pregnancies with the highest total cholesterol, low-density lipoprotein (LDL) or triglyceride levels or the lowest high-density lipoprotein (HDL) levels predict future dyslipidemia post-pregnancy. Longitudinal cohort study. Five communities in Michigan, USA. Pregnant women (n = 649) with blood lipid levels measured at mid-pregnancy in the Pregnancy Outcomes and Community Health (POUCH) Study and at the POUCHmoms Study follow-up, 7-15 years later. Maternal mid-pregnancy lipid levels were defined as 'high' (upper quartile of triglycerides ≥ 216 mg/dL, LDL ≥ 145 mg/dL and total cholesterol ≥ 256 mg/dL) or 'low' (lower quartile, HDL < 58 mg/dL) using whole sample lipid distributions. At follow-up, dyslipidemia was classified by the clinical cutoffs of triglycerides and total cholesterol ≥ 200 mg/dL, LDL ≥ 130 mg/dL and HDL < 50 mg/dL. Weighted regression models estimated the risk of dyslipidemia at follow-up in relation to pregnancy lipid levels, adjusted for baseline confounders. Dyslipidemia later in life. Mid-pregnancy triglycerides, LDL, and total cholesterol levels at the upper quartile were associated with at least threefold increase in the risk of abnormal triglycerides, LDL and total cholesterol levels later in life. Women with low mid-pregnancy HDL levels had just over a twofold increased risk of abnormally low HDL levels at follow-up. These associations persisted following adjustment for covariates, i.e. demographics, lifestyle, and years of follow-up. Higher mid-pregnancy LDL, total cholesterol and triglycerides and lower levels of HDL may signal future dyslipidemia risk and the need for closer lipid monitoring to ensure timely interventions that can attenuate cardiovascular disease risk.

Lipid imaging mass spectrometry: Towards a new molecular histology

Lipid research is attracting greater attention, as these molecules are key components to understand cell metabolism and the connection between genotype and phenotype. The study of lipids has also been fueled by the development of new and powerful technologies, able to identify an increasing number of species in a single run and at decreasing concentrations. One of such key developments has been the image techniques that enable the visualization of lipid distribution over a tissue with cell resolution. Thanks to the spatial information reported by such techniques, it is possible to associate a lipidome trait to individual cells, in fixed metabolic stages, which greatly facilitates understanding the metabolic changes associated to diverse pathological conditions, such as cancer. Furthermore, the image of lipids is becoming a kind of new molecular histology that has great chances to make an impact in the diagnostic units of the hospitals. Here, we examine the current state of the technology and analyze what the next steps to bring it into the diagnosis units should be. To illustrate the potential and challenges of this technology, we present a case study on clear cell renal cell carcinoma, a good model for analyzing malignant tumors due to their significant cellular and molecular heterogeneity.

A-213 Comparison of low-density lipoprotein cholesterol (LDL-c) estimates by in-lab and point-of-care devices in the context of emerging LDL-c equations

Abstract Background Low-density lipoprotein cholesterol (LDL-c) and lipid measurements are used for hyperlipidemia diagnosis, cardiovascular disease risk classification, and medication management. Millions of lipid panels are performed annually. Given the widespread need for lipid testing, there are two CLIA-waived point-of-care (POC) lipid testing devices. These devices were FDA-approved using the Friedewald equation to estimate LDL-c based on measurements of (triglycerides (TG), high-density lipoprotein cholesterol (HDL-c), and total cholesterol (TC). However, in laboratory-based testing, the Friedewald equation is being replaced by newer, more accurate equations such as the NIH-Sampson equation. These equations use the same lipid panel results to estimate LDL-c and only differ in the arithmetic of the estimation. The study objective is to evaluate how differences between the in-clinic POC machines and in-laboratory lipid measurements affect the estimated LDL-c results and are compounded by differences in the equations used for LDL-c estimation. Methods This retrospective observational study collected deidentified lipid results (TG, HDL-c, TC, LDL-c) and demographic data (age, gender) for all samples that had lipid panel results from in-lab and POC within twenty-four hours of each other in a single hospital system between 2014 and 2023. Three hundred twenty samples were identified; samples with non-numerical values or results outside of the reportable range for TG, HDL-c, or TC were not included in subsequent LDL-c calculations using the Friedewald and NIH-Sampson equations (69 results). Patients under the age of 18 were excluded (2 results). Two hundred and forty-nine samples met inclusion criteria; this cohort showed non-significant differences in lipid, age, and gender distributions relative to all POC results tested in the same time frame. Results Consistent with prior reports, we observed discordance between POC and the in-lab lipid measurements, particularly for TG (Bland-Altman: bias:-23.04 mg/dL, standard deviation:61.3 mg/dL). Regardless of the testing platform, LDL-c results are higher on an individual and population-based level with the NIH-Sampson equation. These analytical differences may not change clinical management if the cardiovascular risk classification using estimated LDL-c is unchanged. However, the risk classification based on the in-lab versus in-clinic testing differed for 20-30% of patients. The most pronounced difference in LDL-c estimation occurred when the POC machine used Friedewald and in-lab testing used NIH-Sampson, and resulted in 5% more patients differentially classified. Conclusions This study highlights the need for transparency in lipid panel reports regarding which LDL-c equation is used in both POC and in-lab testing formats, and the need for readily available tools for conversion between different LDL-c estimation equations.

Constraining the sources of archaeal tetraether lipids in multiple cold seep provinces of the Cascadia Margin

Archaeal isoprenoid glycerol dialkyl glycerol tetraether lipid (iGDGT) abundance profiles and carbon isotopic compositions reflect the relative distributions of archaeal sources, including planktonic, benthic, and methane-cycling contributions. Here, we analyze the carbon isotope ratios of iGDGTs purified from sediments of three different cold seep sites in Cascadia Margin, off the coast of Washington, USA. Together with relative abundance and glycerol configurations, we use the carbon isotope ratios to estimate the contributions of multiple archaeal sources to the sedimentary iGDGT assemblages and their impact on values of the TEX86 and methane indices. Using a Bayesian mixing model, we robustly characterize three potential endmembers by determining their characteristic lipid distributions, inferred contributions to the total sediment inventory, and carbon isotopic signatures. Despite the geographic proximity of the sample locations, we find site-specific heterogeneity in relative iGDGT abundances and δ13C values. Planktonic and benthic methane-cycling sources predominate in all cases (contributing > 98 % of iGDGTs), while benthic non-methane cycling archaea contribute minimally to the sedimentary lipid pool. Environments with higher methane influence show an increased presence of anti-parallel iGDGTs, indicating that methane-cycling archaea may dominantly or exclusively synthesize iGDGTs in this configuration. Our results quantify the relationship between the methane index (MI) and methane impact in systems dominated by planktonic and benthic methane-cycling archaea. Within the framework of the TEX86 temperature proxy, this permits a quantitative demonstration that it is overly simplistic to apply a MI cutoff threshold as a binary indicator to determine methane influence, and caution is needed when taking this approach in paleoclimate reconstructions.

Robust lipid scrambling by TMEM16 proteins requires an open groove and thin membrane.

Biological membranes are complex and dynamic structures with different populations of lipids on their inner and outer leaflets. The Ca2+-activated TMEM16 family of membrane proteins play an important role in collapsing this asymmetric lipid distribution by spontaneously, and bidirectionally, scrambling phospholipids between the two leaflets, which can initiate signaling and alter the physical properties of the membrane. While evidence shows that lipid scrambling occurs via an open hydrophilic pathway ("groove") that spans the membrane, it remains unclear if all family members facilitate lipid movement in this manner. Here we present a comprehensive computational study of lipid scrambling by all TMEM16 members with experimentally solved structures. We performed coarse-grained molecular dynamics (MD) simulations of 27 structures from five different family members solved under activating and non-activating conditions, and we captured over 700 scrambling events in aggregate. This enabled us to directly compare scrambling rates, mechanisms, and protein-lipid interactions for fungal and mammalian TMEM16s, in both open (Ca2+-bound) and closed (Ca2+-free) conformations with statistical rigor. We show that nearly all (>90%) scrambling occurs in the dilated groove and the degree of induced membrane thinning positively correlates with the scrambling rate. Surprisingly, we also observed 60 scrambling events that occurred outside the canonical groove, over 90% of which took place at the dimer-dimer interface in mammalian TMEM16s. This new site suggests an alternative mechanism for lipid scrambling in the absence of an open groove.

Ameliorated lipid distribution in prediabetes - Effects of 12 weeks traditional Chinese YiJinJing exercise plus TheraBand: A randomized controlled trial

ObjectiveLipid distribution plays a crucial role in glucose metabolism, and this study aimed to investigate the effects of 12 weeks traditional Chinese YiJinJing exercise on specific lipid distributions in patients with prediabetes. MethodsSixty participants with prediabetes were randomly allocated to either a control group (Con, n = 30) or an exercise group (Ex, n = 30). The Ex group underwent YiJinJing exercise plus Theraband, engaging in 1-h sessions, 3 times per week, over a total period of 12 weeks. Dual-energy X-ray absorptiometry (DEXA) and magnetic resonance imaging (MRI) were used to measure lipid distribution in different body segments and organs. Additionally, a body composition analyser was employed to measure visceral fat, and laboratory tests were conducted to measure indicators related to glycolipid metabolism. ResultsFollowing a 12-week intervention with Exercise, 37 % of prediabetic patients in the Ex group achieved normal blood glucose levels. Significant reductions were observed in upper limb fat (ULF), trunk fat (TrF) and liver fat (LF) values in the Ex group compared to the Con group. Additionally, within the Ex group, there were notable decreases in triglyceride (TG) levels, body mass index (BMI), waist-hip ratio (WHR), android fat (AF), ULF, thigh fat (ThF), renal sinus fat (RSF), and LF compared to baseline. ConclusionsTraditional Chinese YiJinJing plus TheraBand exercise can significantly reduce blood glucose levels through improved lipid distribution and metabolism in prediabetic patients. Hence, YiJinJing can serve as a crucial intervention for individuals with prediabetes.

Association of non-high-density lipoprotein to high-density lipoprotein ratio (NHHR) with prognosis in cancer survivors: a population-based study in the United States.

Patients with cancer frequently exhibit alterations in serum lipid profiles associated with chemotherapy. It has been reported that lipid distribution in cancer correlates with tumor progression. However, the prognostic value of serum lipid biomarkers in cancer survivors remains a subject of debate. We aim to explore the relationship between non-high-density lipoprotein to high-density lipoprotein ratio (NHHR) and the prognosis of cancer survivors. In this study, we analyzed cancer survivor data from the National Health and Nutrition Examination Survey (NHANES) from 1999-2000 to 2017-2018. The study included prospective cohorts that included total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) levels as well as mortality data. Weighted multivariate cox regression models, competing risk models and restricted cubic spline (RCS) models were applied to investigate the association between NHHR and cancer survival. Subgroup and sensitivity analyses were performed to test the robustness of the results. This study involved 4,177 participants, representing about 19.6 million U.S. adults. After adjustment for various factors, the lower NHHR group (≤1.64) had a 31% (HR 1.31; 95% CI [1.11,1.54], p = 0.001) higher risk of death from any cause compared to the higher NHHR group. The link between NHHR and mortality remained stable across most subgroups, with notable interactions for smoking (p = 0.006) and diabetes status (p = 0.046). A J-shaped pattern was observed between NHHR and all-cause mortality, significantly among obesity-related cancer survivors (overall association test p-value = 0.0068, non-linear association test p-value = 0.0016). However, a non-significant negative correlation was observed for cancer-specific mortality (overall association test p-value = 0.48, non-linear association test p-value = 0.66). Considering the competitive risk of heart disease and cancer-specific mortality, there is no difference between the high and low NHHR groups, while the low NHHR group showed an increased risk of non-specific causes of death (p < 0.001). The results of this study suggest that NHHR is an important indicator that is strongly associated with all-cause mortality in cancer survivors, and that this relationship may be influenced by the interaction of diabetes and smoking status. This finding may provide important information for future research and patient management.

Differential effects of melatonin on adipose tissues under normoestrogenic and estrogen-deficient conditions in rats

In post-menopause, oxidative stress due to the decline of natural antioxidants increases the susceptibility to metabolic syndromes (MetS). Estrogen and melatonin (MEL) share antioxidant properties; however, few studies have reported the impact of estrogen deficiency and MEL treatment on morphology, redox status, and antioxidant defense capacity of diverse adipose tissue (AT) subtypes. To investigate this issue, MEL was administered to ovariectomized (OVX) rats and sham-operated rats for 16 weeks (10 mg/kg). The adipocyte morphology, oxidative stress parameters and antioxidant enzyme activity were evaluated in the visceral retroperitoneal adipose tissue (rVAT), subcutaneous inguinal adipose tissue (iSAT) and brown adipose tissue (BAT). In OVX rats, MEL treatment suppressed rVAT hypertrophy and increased the prevalence of small adipocytes in iSAT, suggesting a better lipid distribution among ATs. MEL treatment increased glutathione reductase and glucose-6-phosphate dehydrogenase activity in iSAT; therefore, restored the glutathione level. In rVAT, MEL increased glutathione peroxidase and glutathione reductase activity. MEL minimized the risks for the development of metabolic abnormalities due to estrogen deficiency. However, under normoestrogenic condition, MEL decreased plasma estradiol levels and uterine mass, raising the concerning of its effect on reproductive functions.

Tracing de novo Lipids using Stable Isotope Labeling LC-TIMS-TOF MS/MS.

Lipids are highly diverse, and small changes in lipid structures and composition can have profound effects on critical biological functions. Stable isotope labeling (SIL) offers several advantages for the study of lipid distribution, mobilization, and metabolism, as well as de novo lipid synthesis. The successful implementation of the SIL technique requires the removal of interferences from endogenous molecules. In the present work, we describe a high-throughput analytical protocol for the screening of SIL lipids from biological samples; examples will be shown of lipid de novo identification during mosquito ovary development. The use of complementary liquid chromatography trapped ion mobility spectrometry and mass spectrometry allows for the separation and lipids assignment from a single sample in a single scan (<1 h). The described approach takes advantage of recent developments in data-dependent acquisition and data-independent acquisition, using parallel accumulation in the mobility trap followed by sequential fragmentation and collision-induced dissociation. The measurement of SIL at the fatty acid chain level reveals changes in lipid dynamics during the ovary development of mosquitoes. The lipids de novo structures are confidently assigned based on their retention time, mobility, and fragmentation pattern.

Engineering Phosphatidylserine Containing Asymmetric Giant Unilamellar Vesicles.

The plasma membrane lipid distribution is asymmetric, with several anionic lipid species located in its inner leaflet. Among these, phosphatidylserine (PS) plays a crucial role in various important physiological functions. Over the last decade several methods have been developed that allow for the fabrication of large or giant unilamellar vesicles (GUVs) with an asymmetric lipid composition. Investigating the physicochemical properties of PS in such asymmetric lipid bilayers and studying its interactions with proteins necessitates the reliable fabrication of asymmetric GUVs (aGUVs) with a high degree of asymmetry that exhibit PS in the outer leaflet so that the interaction with peptides and proteins can be studied. Despite progress, achieving aGUVs with well-defined PS asymmetry remains challenging. Recently, a Ca2+-initiated hemifusion method has been introduced, utilizing the fusion of symmetric GUVs (sGUVs) with a supported lipid bilayer (SLB) for the fabrication of aGUVs. We extend this approach to create aGUVs with PS in the outer bilayer leaflet. Comparing the degree of asymmetry between aGUVs obtained via Ca2+ or Mg2+ initiated hemifusion of a phosphatidylcholine (PC) sGUVwith a PC/PS-supported lipid bilayer, we observe for both bivalent cations a significant number of aGUVs with near-complete asymmetry. The degree of asymmetry distribution is narrower for physiological salt conditions than at lower ionic strengths. While Ca2+ clusters PS in the SLB, macroscopic domain formation is absent in the presence of Mg2+. However, the clustering of PS upon the addition of Ca2+ is apparently too slow to have a negative effect on the quality of the obtained aGUVs. We introduce a data filtering method to select aGUVs that are best suited for further investigation.

The impact of methylparaben and chlorine on the architecture of Stenotrophomonas maltophilia biofilms

The biofilm architecture is significantly influenced by external environmental conditions. Biofilms grown on drinking water distribution systems (DWDS) are exposed to environmental contaminants, including parabens, and disinfection strategies, such as chlorine. Although changes in biofilm density and culturability from chemical exposure are widely reported, little is known about the effects of parabens and chlorine on biofilm morphology and architecture. This is the first study evaluating architectural changes in Stenotrophomonas maltophilia colony biofilms (representatives of bacterial communities presented in DWDS) induced by the exposure to methylparaben (MP) at environmental (15 μg/L) and in-use (15 mg/L) concentrations, and chlorine at 5 mg/L, using widefield epi-fluorescence mesoscopy with Mesolens. The GFP fluorescence of colony biofilms allowed the visualization of internal structures and Nile Red fluorescence permitted the inspection of the distribution of lipids. Our data show that exposure to MP triggers physiological and morphological adaptation in mature colony biofilms by increasing the complexity of internal structures, which may confer protection to embedded cells from external chemical molecules. These architectural modifications include changes in lipid distribution as an adaptive response to MP exposure. Although chlorine exposure affected colony biofilm diameter and architecture, the colony roundness was completely affected by the simultaneous presence of MP and chlorine. This work is pioneer in using Mesolens to highlight the risks of exposure to emerging environmental contaminants (MP), by affecting the architecture of biofilms formed by drinking water (DW) bacteria, even when combined with routine disinfection strategies.