Hyperexpansion of genetic diversity and metabolic capacity of extremophilic bacteria and archaea in ancient Andean lake sediments.

BACKGROUND: The Andean Altiplano hosts a repertoire of high-altitude lakes with harsh conditions for life. These lakes are undergoing a process of desiccation caused by the current climate, leaving terraces exposed to extreme atmospheric conditions and serving as analogs to Martian paleolake basins. Microbiomes in Altiplano lake terraces have been poorly studied, enclosing uncultured lineages and a great opportunity to understand environmental adaptation and the limits of life on Earth. Here we examine the microbial diversity and function in ancient sediments (10.3-11 kyr BP (before present)) from a terrace profile of Laguna Lejía, a sulfur- and metal/metalloid-rich saline lake in the Chilean Altiplano. We also evaluate the physical and chemical changes of the lake over time by studying the mineralogy and geochemistry of the terrace profile. RESULTS: The mineralogy and geochemistry of the terrace profile revealed large water level fluctuations in the lake, scarcity of organic carbon, and high concentration of SO42--S, Na, Cl and Mg. Lipid biomarker analysis indicated the presence of aquatic/terrestrial plant remnants preserved in the ancient sediments, and genome-resolved metagenomics unveiled a diverse prokaryotic community with still active microorganisms based on in silico growth predictions. We reconstructed 591 bacterial and archaeal metagenome-assembled genomes (MAGs), of which 98.8% belonged to previously unreported species. The most abundant and widespread metabolisms among MAGs were the reduction and oxidation of S, N, As, and halogenated compounds, as well as aerobic CO oxidation, possibly as a key metabolic trait in the organic carbon-depleted sediments. The broad redox and CO2 fixation pathways among phylogenetically distant bacteria and archaea extended the knowledge of metabolic capacities to previously unknown taxa. For instance, we identified genomic potential for dissimilatory sulfate reduction in Bacteroidota and α- and γ-Proteobacteria, predicted an enzyme for ammonia oxidation in a novel Actinobacteriota, and predicted enzymes of the Calvin-Benson-Bassham cycle in Planctomycetota, Gemmatimonadota, and Nanoarchaeota. CONCLUSIONS: The high number of novel bacterial and archaeal MAGs in the Laguna Lejía indicates the wide prokaryotic diversity discovered. In addition, the detection of genes in unexpected taxonomic groups has significant implications for the expansion of microorganisms involved in the biogeochemical cycles of carbon, nitrogen, and sulfur. Video Abstract.

Assessing the potential of n-alkyl amides and n-alkyl nitriles in the arid sedimentary strata of northwestern China as environmental indicators.

Recent advancements in the application of lipid biomarkers as paleoenvironmental indicators have provided invaluable insights into the dynamics of climatic variations, vegetative histories, and anthropogenic impacts. However, our current understanding of nitrogen-containing lipid biomarkers (NCLBs) in sedimentary deposits remains limited, notwithstanding their potential significance in global nitrogen cycling. To bridge this research gap, a comprehensive study was conducted to characterize the distribution patterns of n-alkyl amides (NAAs) and n-alkyl nitriles (NANs) in representative paleo-lake and loess sedimentary profiles from the arid region of northwestern China (NWC). The widespread occurrence of these NCLBs across late Quaternary strata, with distinct distribution patterns observed in various settings, suggests their formation under diverse environmental conditions. The prevalence of NAAs in arid sedimentary deposits can primarily be attributed to the diverse array of local biota, including vascular plants, algae, and fungi, rather than being solely associated with biomass burning, as commonly assumed. Furthermore, the distribution patterns of NANs closely align with those of NAAs, indicating their formation through thermally induced dehydration of precursor NAAs. Both groups of NCLBs exhibit significant preservation potential in sediments within NWC, which is believed to be intimately linked to the region's arid and cold climate as well as its neutral or weakly alkaline depositional setting. These findings underscore the prospective use of NAAs as indicators of environmental changes and NANs as potential markers of past fire-related activities, making them valuable tools for paleoenvironmental reconstructions of late Quaternary strata, especially in arid, cold, and weakly alkaline regions.

Atherogenic Combined Index: Validation of a Novel Predictive Lipid Biomarker for the Presence and Severity of Coronary Artery Disease.

BACKGROUND/AIM: The balance between atherogenic and antiatherogenic lipid particles significantly influences coronary artery disease (CAD), as an imbalance may contribute to the development and progression of atherosclerosis, which affects the risk and severity of CAD. This study aims to introduce and validate the atherogenic combined index (ACI) as a novel lipid biomarker that, comprehensively assesses the balance between atherogenic and antiatherogenic particles in the blood to effectively reflect the cumulative atherogenic effect and its association with the presence and severity of CAD. MATERIAL AND METHODS: In this cross-sectional study, 1,830 patients diagnosed with CAD and a total of 650 patients without CAD were included in the study cohort for comprehensive analysis and comparison. Based on the tertiles of the SYNTAX score (SS), three subgroups of patients with CAD were identified. ACI and other atherogenic indices were compared to predict the presence and severity of CAD. RESULTS: The levels of ACI and other non-traditional lipid markers levels were higher in the CAD group compared to the non-CAD group (p <0.05, for all). ACI showed a good linear association with the SYNTAX score (r = 0.527; p <0.001). The multivariate logistic regression model showed that ACI was an independent predictor of the presence (OR: 1.602, 95% CI: 1.509-1.701, p <0.001) and severity (OR: 1.296, 95% CI: 1.243-1.351, p <0.001) of CAD after adjustment for various confounders. CONCLUSION: The results suggest that ACI may serve as a promising and stronger tool for predicting the presence and severity of CAD.

Lipid biomarkers in colorectal cancer, with particular emphasis on exosomes - current status and future inferences.

INTRODUCTION: Colorectal cancer (CRC) is one of the most deadly cancers on a global scale. Diagnosis of CRC is challenging and it is often detected at a late stage. Identification of relevant biomarkers could lead to the development of effective diagnostic methods for CRC. AREAS COVERED: We reviewed the literature on lipid (including exosomal) biomarkers that have the potential to become common, minimally invasive and effective diagnostic tools for CRC. We showed that differences in lipid levels (single compounds and entire panels) make it possible to classify patients into diseased or healthy groups, determine the stage of CRC, as well as accompanying inflammation and immune reactions associated with tumorigenesis. We also discussed exosomes which are important components of the tumor microenvironment that influence tumor progression and for which only a small number of studies were conducted so far in this area. EXPERT OPINION: A rapid development in the field of lipid-based biomarkers, including exosomal lipid biomarkers, is expected as growing evidence shows their potential application and good accuracy. However, one of the major issues that needs to be addressed within this topic is to translate findings into a noninvasive and versatile diagnostic test robustly validated in clinical conditions.

Lipid biomarkers and stable isotopes uncover paleovegetation changes in extremely species-rich forest-steppe ecosystems, Central Europe.

The historical development of the vegetation of semi-dry grasslands in Central Europe is not satisfactorily understood. Long-term continuity of open vegetation or, conversely, deep-past forest phases are considered possible sources of the current extreme species diversity of these ecosystems. We aimed to reveal the trajectory of paleovegetation development in these ecosystems through detailed analysis of terrestrial in-situ soil geoarchives. We measured the bulk soil carbon and nitrogen contents, lipid molecular distribution, and compound-specific stable carbon and hydrogen isotopic signatures of mid- and long-chain n-alkanes extracted from soil and modern plant material tissues (i.e., deciduous and Pinus leaves and grass/herbaceous species). The C23-C33 n-alkane homologues were identified in soils with different abundances. Normally, C27 and C29 n-alkanes were the most abundant homologues in tree-leaf samples, while grass-derived n-alkanes were mostly C31 and C33 homologues. Soils were largely dominated by C29 and C31 n-alkanes. Odd-numbered C27-C33 soil n-alkane δ13C values ranged from -36.2‰ to -23.2‰, whereas their δ2H values showed a wider range of variability that fluctuated from -224‰ to -172‰. Molecular distribution in combination with radiocarbon analysis of soil organic matter (SOM) and δ13C and δ2H values of n-alkanes revealed a large contribution of C3 trees (both deciduous and coniferous trees/pine trees) as the main source of n-alkanes between the late Pleistocene and early Holocene (ca 15,000-8200 calibrated year before present/cal year BP). A clear shift toward more grassy/herbaceous vegetation was observed from the early Holocene (ca 11,700-8200 cal year BP) onwards. Distribution patterns of lipids and soil geochemical parameters showed that plants are the main source of SOM and that biodegradation and kinetic isotope fractionation are not the main reasons for 13C enrichment in soil profiles. Past C3 vegetation shifts as well as paleoclimate changes (i.e., aridity) can have played a role in the observed 13C depth profiles.

Changes in Lipid Profiles with the Progression of Pregnancy in Black Women.

Background/Objectives: Lipid metabolism plays an important role in maternal health and fetal development. There is a gap in the knowledge of how lipid metabolism changes during pregnancy for Black women who are at a higher risk of adverse outcomes. We hypothesized that the comprehensive lipidome profiles would show variation across pregnancy indicative of requirements during gestation and fetal development. Methods: Black women were recruited at prenatal clinics. Plasma samples were collected at 8-18 weeks (T1), 22-29 weeks (T2), and 30-36 weeks (T3) of pregnancy. Samples from 64 women who had term births (≥37 weeks gestation) were subjected to "shotgun" Orbitrap mass spectrometry. Mixed-effects models were used to quantify systematic changes and dimensionality reduction models were used to visualize patterns and identify reliable lipid signatures. Results: Total lipids and major lipid classes showed significant increases with the progression of pregnancy. Phospholipids and glycerolipids exhibited a gradual increase from T1 to T2 to T3, while sphingolipids and total sterol lipids displayed a more pronounced increase from T2 to T3. Acylcarnitines, hydroxy acylcarnitines, and Lyso phospholipid levels significantly decreased from T1 to T3. A deviation was that non-esterified fatty acids decreased from T1 to T2 and increased again from T2 to T3, suggestive of a potential role for these lipids during the later stages of pregnancy. The fatty acids showing this trend included key fatty acids-non-esterified Linoleic acid, Arachidonic acid, Alpha-linolenic acid, Eicosapentaenoic acid, Docosapentaenoic acid, and Docosahexaenoic acid. Conclusions: Mapping lipid patterns and identifying lipid signatures would help develop intervention strategies to reduce perinatal health disparities among pregnant Black women.

Metal exposure and blood lipid biomarkers in early pregnancy: A cross-sectional study.

Recognizing the risk factors for dyslipidemia during pregnancy is crucial for safeguarding the health of both the mothers and the offspring. Growing evidence emerged and suggested links between environmental factors, including metals, and alteration in lipid levels or dyslipidemia in general populations. However, knowledge of the associations during pregnancy remains extremely lacking. Herein, we aimed to explore whether elevated metal exposure constitutes a risk factor for dyslipidemia in pregnant women. Based on the Tongji-Shuangliu Birth Cohort (TSBC), a total of 663 pregnant women were recruited and their urinary levels of 17 metals and blood lipid biomarkers in early pregnancy were measured, namely triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). The multivariable linear regression models revealed that exposure to selected metals during early pregnancy was significantly associated with some important biomarkers. In particular, after natural log-transformed for the levels of lipid biomarkers and metals, copper (Cu) exposure was positively associated with HDL-C (ß = 0.024, 95% CI: 0.001, 0.046), while zinc (Zn) was associated with TG (ß = 0.062, 95% CI: 0.013, 0.110) and selenium with TC (ß = 0.028, 95% CI: 0.004, 0.054). Exposure to rubidium (Rb) was positively associated with multiple lipid biomarkers, including HDL-C (ß = 0.020, 95% CI: 0.002, 0.037) and LDL-C (ß = 0.022, 95% CI: 0.001, 0.042). Mixture exposure analysis further identified significant associations between Cu and HDL-C, Zn and TG, Rb and HDL-C, when multiple metal exposures were considered in the Bayesian kernel machine regression model simultaneously. Our findings showed that exposure to several metals during early pregnancy was associated with an increased prevalence of blood lipid abnormalities in pregnant women. These findings underscore the potential impact of metal combinations on lipid metabolism and increase our understanding of the risk factors associated with abnormal lipid metabolism during pregnancy.

Obesity and dyslipidemia in early life: Impact on cardiometabolic risk.

Childhood obesity with its growing prevalence worldwide presents one of the most important health challenges nowadays. Multiple mechanisms are involved in the development of this condition, as well as in its associations with various cardiometabolic complications, such as insulin resistance, diabetes, metabolic dysfunction-associated steatotic liver disease and cardiovascular diseases. Recent findings suggest that childhood obesity and associated dyslipidemia at least partly originate from epigenetic modifications that take place in the earliest periods of life, namely prenatal and perinatal periods. Hence, alterations of maternal metabolism could be fundamentally responsible for fetal and neonatal metabolic programming and consequently, for metabolic health of offspring in later life. In this paper, we will review recent findings on the associations among intrauterine and early postnatal exposure to undesirable modulators of metabolism, development of childhood obesity and later cardiometabolic complications. Special attention will be given to maternal dyslipidemia as a driven force for undesirable epigenetic modulations in offspring. In addition, newly proposed lipid biomarkers of increased cardiometabolic risk in obese children and adolescents will be analyzed, with respect to their predictive potential and clinical applicability.

Peatland warming influences the abundance and distribution of branched tetraether lipids: Implications for temperature reconstruction.

Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are bacterial membrane lipids whose distribution in peatland soils serves as an important proxy for past climate changes due to strong linear correlations with temperature in modern environments. However, commonly used brGDGT-based temperature models are characterized by high uncertainty (ca. 4 °C) and these calibrations can show implausible correlations when applied at an ecosystem level. This lack of accuracy is often attributed to our limited understanding of the exact mechanisms behind the relationship between brGDGTs and temperature and the potential effect of temperature-independent factors on brGDGT distribution. Here, we examine the abundance and distribution of brGDGTs in a boreal peatland after four years of in-situ warming (+0, +2.25, +4.5, +6.75 and +9 °C). We observed that with warming, concentrations of total brGDGTs increased. Furthermore, we determined a shift in brGDGT distribution in the surface aerobic layers of the acrotelm (0-30 cm depth), whereas no detectable change was observed at deeper anaerobic depths (>40 cm), possibly due to limited microbial activity. The response of brGDGTs to warming was also reflected by a strong increase in the methylation index of 5-methyl brGDGTs (MBT'5Me), classically used as a temperature proxy. Further, the relationship between the MBT'5Me index and soil temperature differed between 0-10, 10-20 and 20-30 cm depth, highlighting depth-specific response of brGDGTs to warming, which should be considered in paleoenvironmental and paleoecological studies. As the bacterial community composition was generally unaltered, the rapid changes in brGDGT distribution argue for a physiological adaptation of the microorganisms producing these lipids. Finally, soil temperature and water table depth were better predictors of brGDGT concentration and distribution, highlighting the potential for these drivers to impact brGDGT-based proxies. To summarize, our results provide insights on the response of brGDGT source microorganisms to soil warming and underscore brGDGTs as viable temperature proxies for better understanding of climatic perturbation in peatlands.

Lipid-based paleoecological and biogeochemical reconstruction of Store Saltsø, an extreme lacustrine system in SW Greenland.

Polar lakes harbour a unique biogeochemistry that reflects the implications of climatic fluctuations against a susceptible yet extreme environment. In addition to polar, Store Saltsø (Kangerlussuaq, southwestern Greenland) is an endorheic lake with alkaline and oligotrophic waters that host a distinctive ecology adapted to live in such particular physico-chemical and environmental conditions. By exploring the sedimentary record of Store Saltsø at a molecular and compound-specific isotopic level, we were able to understand its ecology and biogeochemical evolution upon climate change. We employed lipid biomarkers to identify biological sources and metabolic traits in different environmental samples (shore terrace, sediment core, and white precipitates at the shore), and their succession over time to reconstruct the lake paleobiology. Different molecular ratios and geochemical proxies provided further insights toward the evolution of environmental conditions in the frame of the deglaciation history of Kangerlussuaq. The relative abundance of terrestrial (i.e., plant derived) biomarkers (odd long-chain n-alkanes, even long-chain n-alkanols, and phytosterols) in the upper half of the shore terrace versus the relatively more present aquatic biomarkers (botryococcenes and long-chain alkenones) in its lower half revealed higher lake water levels in the past. Moreover, the virtual absence of organics in the deepest section of the sediment core (32-29 cm depth) suggested that the lake did not yet exist at the northwestern shore of Store Saltsø ∼5100 years ago. According to the relative abundance of lipid biomarkers detected in the adjacent section above (29-25 cm depth), we hypothesize that the northwestern shore of Store Saltsø formed ∼4900 years ago. By combining the molecular and compound-specific isotopic analysis of lipids in a ∼360 cm sedimentary sequence, we recreated the paleobiology and evolution of an extreme lacustrine environment suitable for the study of the limits of life and the effects of climate warming.

The Association Between Blood Mercury and Lipid Biomarkers in US Hypertensive Adults.

Mercury (Hg) is detrimental to human health, but its impact on lipid biomarkers remains a subject of controversy. This study sought to delineate a clear link between blood Hg and lipid biomarkers correlated with cardiovascular disease (CVD), including total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG), in hypertensive adults in the USA. METHODS: This cross-sectional research gathered data from a total of 4415 participants sourced from the National Health and Nutrition Examination Survey (NHANES). The Holm-Bonferroni stepdown procedure was utilized to control the type I error rate in multiple comparisons. We employed multivariable linear regression models to assess the correlation between blood Hg and lipid biomarkers. Subsequently, subgroup analyses were conducted, categorized by both gender and race. Additionally, we used smooth curve fittings and generalized additive models to confirm the presence of non-linear relationships. When non-linearity was detected, we applied a recursive algorithm to calculate the inflection points. Finally, we established a weighted two-piecewise linear regression model to illustrate the associations on either side of the inflection point. RESULTS: In our multivariable linear regression models, clear associations emerged. Specifically, positive correlations were observed between blood mercury and TC (ß = 0.025; 95% CI 0.009 to 0.041; corrected P = 0.011), LDL-C (ß = 0.022; 95% CI 0.007 to 0.036; corrected P = 0.012), and HDL-C (ß = 0.007; 95% CI 0.001 to 0.013; corrected P = 0.058). However, there was no significant correlation with TG (ß = - 0.007; 95% CI - 0.018 to 0.004; corrected P = 0.526). Notably, it has been demonstrated that distinct inverted U-shaped and U-shaped curves exist when stratified by gender in our analysis. CONCLUSIONS: Blood Hg exhibited a positive correlation with TC, LDL-C, and HDL-C in hypertensive adults in the USA. Nonetheless, no significant association was observed with TG.

Anthropogenic multipollutant input to the offshore South China Sea.

The remote region of the South China Sea (SCS), situated far from urban mainland areas, is commonly perceived to experience minimal pollution. However, this may evolve into a considerably polluted region owing to increasing anthropogenic pollutants. In this study, we employ a multidisciplinary approach to analyze the surface sediments collected from the offshore area of the southern SCS. Our aim is to explore potential anthropogenic pollutants, their interactions, and the related controlling factors. This research endeavors to enhance our understanding of the current pollution status in the SCS and help making relevant policy management decisions. Comparison with previous reports reveals that now, the area is more extensively and increasingly contaminated by petroleum hydrocarbons and heavy metals (Cd and As) than before. For the first time, we report the recognition of coprostanol and long-chain alkyl mid-chain ketones, unveiling the noticeable incorporation of sewage fecal matter and biomass burning into offshore sediments. Moreover, sedimentary multipollutants (except ketones) exhibit strong correlations with terrestrial elements and fine-sized particles, displaying a roughly high-west/low-east spatial variability in pollutant accumulation or enrichment. These signatures evidently demonstrate the major impact of river discharges (e.g., the Mekong River to the west and the Pearl and Red Rivers to the north) on the SCS. They have hydrodynamic effects on the subsequent basin-wide dispersal of pollutants, driven by monsoon-induced large- and regional-scale currents. The different behavior of burning-related ketones may be partly due to their aerosol form, leading to atmospheric transportation. Because anthropogenic multipollutants pose compounded threats, exacerbating oceanic warming and acidification to marine ecosystems such as the widespread coral reefs in the southern SCS, scientific management of urban emissions is required to mitigate ecosystem degradation in the Anthropocene era.

Serpentinization-associated travertines as spatio-temporal archives for lipid biomarkers key for the search for life on Mars.

Serpentinization is a well-known aqueous alteration process that may have played important roles in the origins and early evolution of life on Earth, and perhaps Mars, but there are still aspects related to biomarker distribution, partitioning, and preservation that merit further study. To assess the role that precipitation of carbonate phases in serpentinization settings may have on biomarker preservation, we search for life signs in one of the world's largest outcrops of subcontinental peridotites (Ronda, South Spain). We investigate the organic record of groundwater and associated carbonate deposits (travertines) in seven hyperalkaline springs, and reconstruct the biological activity and metabolic interactions of the serpentinization-hosted ecosystem. We identified lipid biomarkers and isotopic evidences of life, whose concentration and variety were much lower in groundwater than travertine deposits (ppb/ppt versus ppm level). Groundwater carried organics of abiotic (n-alkanes with values of CPI âˆ¼ 1) and/or biotic origin, of fresher (e.g. acids or alcohols) or more diagenetized (mature hopanes and n-alkanes) nature. In contrast, associated travertines held a more prolific record of biomarkers incorporating (molecular and isotopic) fingerprints of surface (mostly phototrophs) and subsurface (chemolithotrophs, methanogens and/or methanotrophs) life. Serpentinization-associated travertines seem to act as biomolecule archives over time fed by autochthonous and allochthonous sources, hence amplifying the dim biological signal of groundwater. These results illustrate the relevance of serpentinization-associated surface mineral deposits in searching for traces of life on analogous environments on Mars. We highlight the diversity of lipids produced in serpentinizing land environments and emphasize the potential of these geostable biomolecules to preserve fingerprints of life.

Lipidomic diversity and proxy implications of archaea from cold seep sediments of the South China Sea.

Cold seeps on the continental margins are characterized by intense microbial activities that consume a large portion of methane by anaerobic methanotrophic archaea (ANME) through anaerobic oxidation of methane (AOM). Although ANMEs are known to contain unique ether lipids that may have an important function in marine carbon cycling, their full lipidomic profiles and functional distribution in particular cold-seep settings are still poorly characterized. Here, we combined the 16S rRNA gene sequencing and lipidomic approaches to analyze archaeal communities and their lipids in cold seep sediments with distinct methane supplies from the South China Sea. The archaeal community was dominated by ANME-1 in the moderate seepage area with strong methane emission. Low seepage area presented higher archaeal diversity covering Lokiarchaeia, Bathyarchaeia, and Thermoplasmata. A total of 55 core lipids (CLs) and intact polar lipids (IPLs) of archaea were identified, which included glycerol dialkyl glycerol tetraethers (GDGTs), hydroxy-GDGTs (OH-GDGTs), archaeol (AR), hydroxyarchaeol (OH-AR), and dihydroxyarchaeol (2OH-AR). Diverse polar headgroups constituted the archaeal IPLs. High concentrations of dissolved inorganic carbon (DIC) with depleted δ13CDIC and high methane index (MI) values based on both CLs (MICL) and IPLs (MIIPL) indicate that ANMEs were active in the moderate seepage area. The ANME-2 and ANME-3 clades were characterized by enhanced glycosidic and phosphoric diether lipids production, indicating their potential role in coupling carbon and phosphurus cycling in cold seep ecosystems. ANME-1, though representing a smaller proportion of total archaea than ANME-2 and ANME-3 in the low seepage area, showed a positive correlation with MIIPL, indicating a different mechanism contributing to the IPL-GDGT pool. This also suggests that MIIPL could be a sensitive index to trace AOM activities performed by ANME-1. Overall, our study expands the understanding of the archaeal lipid composition in the cold seep and improves the application of MI using intact polar lipids that potentially link to extent ANME activities.

Phospholipidomics in Clinical Trials for Brain Disorders: Advancing our Understanding and Therapeutic Potentials.

Phospholipidomics is a specialized branch of lipidomics that focuses on the characterization and quantification of phospholipids. By using sensitive analytical techniques, phospholipidomics enables researchers to better understand the metabolism and activities of phospholipids in brain disorders such as Alzheimer's and Parkinson's diseases. In the brain, identifying specific phospholipid biomarkers can offer valuable insights into the underlying molecular features and biochemistry of these diseases through a variety of sensitive analytical techniques. Phospholipidomics has emerged as a promising tool in clinical studies, with immense potential to advance our knowledge of neurological diseases and enhance diagnosis and treatment options for patients. In the present review paper, we discussed numerous applications of phospholipidomics tools in clinical studies, with a particular focus on the neurological field. By exploring phospholipids' functions in neurological diseases and the potential of phospholipidomics in clinical research, we provided valuable insights that could aid researchers and clinicians in harnessing the full prospective of this innovative practice and improve patient outcomes by providing more potent treatments for neurological diseases.

Role of lipid signalling in extracellular vesicles-mediated cell-to-cell communication.

Lipid signalling plays a crucial role in extracellular vesicle (EV)-mediated cell-to-cell communication. Extracellular vesicles are small membrane-bound structures released by various cell types into the extracellular environment. They include exosomes, microvesicles, and apoptotic bodies. These vesicles contain a variety of bioactive molecules, including proteins, nucleic acids (such as miRNAs and mRNAs), and lipids. Lipids are important components of EVs and are involved in various aspects of their biogenesis, cargo sorting, and functional effects on target cells. In this review, we will discuss how lipid signalling is involved in EV-mediated cell-to-cell communication. In summary, lipid signalling is intricately involved in extracellular vesicle-mediated cell-to-cell communication. The lipid composition of EVs influences their biogenesis, cargo sorting, interactions with target cells, and functional effects on recipient cells. Understanding the role of lipids in EV-mediated communication is essential for deciphering the mechanisms underlying intercellular signalling and developing potential therapeutic strategies based on EVs.

Causal effects of serum lipid biomarkers on early age-related macular degeneration using Mendelian randomization.

BACKGROUND: Age-related macular degeneration (AMD) is one of the major causes of vision loss. Early AMD needs to be taken seriously, but the causal effects of lipid biomarkers on early AMD remain unclear. METHODS: In this study, two-sample Mendelian randomization (MR) analysis was performed to systematically assess the causal relationships between seven serum lipid biomarkers (apolipoprotein A (ApoA), apolipoprotein B (ApoB), total cholesterol (CHOL), high-density lipoprotein cholesterol (HDL-C), direct low-density lipoprotein cholesterol (LDL-C), lipoprotein A [Lp(a)], and triglycerides (TG)) and risk of early AMD. In total, 14,034 cases and 91,214 controls of European ancestry were included in the analysis (number of SNPs = 11,304,110). RESULTS: MR estimates revealed that a higher HDL-C level is strongly associated with increased risk of early AMD (OR = 1.25, 95% CI: 1.15-1.35, P = 2.61 × 10-8). In addition, level of ApoA is also positively associated with risk of early AMD (OR = 2.04, 95% CI: 1.50-2.77, P = 6.27 × 10-6). Conversely, higher levels of TG significantly decrease the risk of early AMD (OR = 0.77, 95% CI: 0.71-0.84, P = 5.02 × 10-10). Sensitivity analyses further supported these associations. Moreover, multivariable MR analyses, adjusted for the effects of correlated lipid biomarkers, yielded similar results. CONCLUSION: This study identifies causal relationships between elevated circulating HDL-C/ApoA levels and increased risk of early AMD, in addition to finding that TG specifically reduces the risk of early AMD. These findings contribute to a better understanding of the role of lipid metabolism in drusen formation, particularly in early AMD development.

The Determination of the Spatial Distribution of Indigenous Lipid Biomarkers in an Immature Jurassic Sediment Using Time-of-Flight-Secondary Ion Mass Spectrometry.

The ability to detect and map lipids, including potential lipid biomarkers, within a sedimentary matrix using mass spectrometry (MS) imaging may be critical to determine whether potential lipids detected in samples returned from Mars are indigenous to Mars or are contaminants. Here, we use gas chromatography-mass spectrometry (GC-MS) and time-of-flight-secondary ion mass spectrometry (ToF-SIMS) datasets collected from an organic-rich, thermally immature Jurassic geologic sample to constrain MS imaging analysis of indigenous lipid biomarkers in geologic samples. GC-MS data show that the extractable fractions are dominated by C27-C30 steranes and sterenes as well as isorenieratene derivatives. ToF-SIMS spectra from organic matter-rich laminae contain a strong, spatially restricted signal for ions m/z 370.3, m/z 372.3, and m/z 386.3, which we assign to C27 sterenes, cholestane (C27), and 4- or 24-methyl steranes (C28), respectively, as well as characteristic fragment ions of isorenieratene derivatives, including m/z 133.1, m/z 171.1, and m/z 237.1. We observed individual steroid spatial heterogeneity at the scale of tens to hundreds of microns. The fine-scale heterogeneity observed implies that indigenous lipid biomarkers concentrated within specific regions may be detectable via ToF-SIMS in samples with even low amounts of organic carbon, including in samples returned from Mars.

Compound-specific carbon isotope analysis of short-chain fatty acids from Pine tissues: characterizing paleo-fire residues and plant exudates.

Different types of plant tissues and resin can account for the wax lipids found in sedimentary contexts and archaeological samples. Consequently, there is increasing research to characterize the fatty acid carbon isotope ratios of different plant anatomical parts and their plant exudates (resin). With the aim to explore isotopic differences between plant tissues, state of the fine organic matter, effect of thermal degradation, and to identify plant residues we measured the δ13C values of short-chain fatty acids (δ13C16:0 and δ13C18:0) in: i) dead and fresh (collected and immediately dried) pine needles and branches (Pinus canariensis) and pine resin from laboratory-controlled heating experiments and ii) sediment and charred pine tissue samples from a wild pine forest fire. Our results are compared to previously published experimental open-air fire experiments and pine-fuelled archaeological combustion features. We found that for both fatty acid types, there are differences in δ13C signatures among anatomical parts and initial moisture content. These data allow us to characterize the isotopic signature of pine tissue and the effect of degradation on isotopic biomarkers, as well as to estimate combustion temperatures in pine-fuelled anthropogenic fires. Supplementary Information: The online version contains supplementary material available at 10.1007/s12520-023-01815-3.

Widely targeted quantitative lipidomics and prognostic model reveal plasma lipid predictors for nasopharyngeal carcinoma.

BACKGROUND: Dysregulation of lipid metabolism is closely associated with cancer progression. The study aimed to establish a prognostic model to predict distant metastasis-free survival (DMFS) in patients with nasopharyngeal carcinoma (NPC), based on lipidomics. METHODS: The plasma lipid profiles of 179 patients with locoregionally advanced NPC (LANPC) were measured and quantified using widely targeted quantitative lipidomics. Then, patients were randomly split into the training (125 patients, 69.8%) and validation (54 patients, 30.2%) sets. To identify distant metastasis-associated lipids, univariate Cox regression was applied to the training set (P < 0.05). A deep survival method called DeepSurv was employed to develop a proposed model based on significant lipid species (P < 0.01) and clinical biomarkers to predict DMFS. Concordance index and receiver operating curve analyses were performed to assess model effectiveness. The study also explored the potential role of lipid alterations in the prognosis of NPC. RESULTS: Forty lipids were recognized as distant metastasis-associated (P < 0.05) by univariate Cox regression. The concordance indices of the proposed model were 0.764 (95% confidence interval (CI), 0.682-0.846) and 0.760 (95% CI, 0.649-0.871) in the training and validation sets, respectively. High-risk patients had poorer 5-year DMFS compared with low-risk patients (Hazard ratio, 26.18; 95% CI, 3.52-194.80; P < 0.0001). Moreover, the six lipids were significantly correlated with immunity- and inflammation-associated biomarkers and were mainly enriched in metabolic pathways. CONCLUSIONS: Widely targeted quantitative lipidomics reveals plasma lipid predictors for LANPC, the prognostic model based on that demonstrated superior performance in predicting metastasis in LANPC patients.