Eicosanoid storm in infection and inflammation

Ginsenosides from Panax ginseng modulate lipid mediator profiles in human leukocytes by interference with cellular 5-lipoxygenase activity

Lipid mediators are a superfamily of bioactive molecules that are crucially involved in immune responses, regulating all stages of inflammation. Panax (P.) ginseng has pleiotropic pharmacological effects, including anti-cancer, anti-diabetic, and anti-inflammatory properties. Ginsenosides, unique triterpenoid glycosides from the plant's root, are proposed as active ingredients responsible for the immunomodulating potential of P.ginseng. Here, we comprehensively screened 23 ginsenosides for manipulating the lipid mediator network in various primary human innate immune cells. Several ginsenosides selectively inhibited 5-lipoxygenase (5-LOX)-mediated formation of pro-inflammatory leukotriene B4, but not of prostaglandins, in monocyte-derived macrophages and polymorphonuclear leukocytes by a unique irreversible mechanism. Structure-activity relationships revealed (i) higher anti-5-LOX activity of PPD-type ginsenosides, (ii) correlation with lipophilicity (R2 = 0.91), and (iii) eudysmic ratios favoring the 20S-epimers. Our findings highlight ginsenosides as immunomodulatory principles of P. ginseng and reveal abrogation of leukotriene formation rather than interference with prostaglandins as immediate anti-inflammatory mechanism.

Systematic Profile of Oxylipins in Myocardial Infarction by Liquid Chromatography-Tandem Mass Spectrometry

RATIONALE

Oxylipins play an important role in inflammatory processes, accompanying the occurrence of myocardial infarction. Analyzing a wide panel of oxylipins derived from more polyunsaturated fatty acids may provide valuable information to elucidate the relationships between the signaling mediator profile and myocardial infarction comprehensively.

METHODS

An ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for simultaneously measuring 74 oxylipins in 50-μL human samples with a 10-min chromatographic run and easy operation has been developed and validated.

RESULTS

Accuracy and precision were below 15% of the relative errors in 99% of quality control. Recoveries and matrix effect were considered acceptable. Potential effects of different collecting tubes were also assessed. We successfully utilized our approach to measure plasma samples obtained from 99 healthy individuals and 302 myocardial infarction patients.

CONCLUSIONS

Profiles of oxylipins discovered potential biomarkers and clarified the pathological characteristics of oxylipin metabolism in myocardial infarction. Our approach was rapid, accurate, and precise, with high throughput, low sample volume, and easy operation, suitable for large-scale studies.

ATP-release pannexin channels are gated by lysophospholipids

In addition to its role as cellular energy currency, adenosine triphosphate (ATP) serves as an extracellular messenger that mediates diverse cell-to-cell communication. Compelling evidence supports that ATP is released from cells through pannexins, a family of membrane proteins that form heptameric large-pore channels. However, the activation mechanisms that trigger ATP release by pannexins remain poorly understood. Here, we discover lysophospholipids as endogenous pannexin activators, using activity-guided fractionation of mouse tissue extracts combined with untargeted metabolomics and electrophysiology. We show that lysophospholipids directly and reversibly activate pannexins in the absence of other proteins. Secretomics experiments reveal that lysophospholipid-activated pannexin 1 leads to the release of not only ATP but also other signaling metabolites, such as 5'-methylthioadenosine, which is important for immunomodulation. We also demonstrate that lysophospholipids activate endogenous pannexin 1 in human monocytes, leading to the release of IL-1β through inflammasome activation. Our results provide a connection between lipid metabolism and purinergic signaling, both of which play major roles in immune responses.

Joint transcriptomics and metabolomics unveil the protective mechanism of tamarind seed polysaccharide against antibiotic-induced intestinal barrier damage

Intestinal barrier damage is frequently caused by antibiotic therapy, potentially leading to bacterial translocation and toxin leakage, which triggers inflammation and increases the risk of various diseases. In this study, Tamarind seed polysaccharides (TSP) with different molecular weights were administered to mice during the recovery phase from clindamycin-induced intestinal barrier damage. The results indicated that TSP restored the shortened colon length, reduced the enlarged cecum index, and decreased the elevated level of inflammatory infiltration. Biochemical testing revealed that TSP decreased the levels of intestinal permeability biomarkers and inflammatory factors that were elevated by clindamycin treatment. Transcriptomics and non-targeted metabolomics analyses respectively uncovered changes in colon gene expression and fecal metabolites. The joint analysis of these omics data identified critical pathways, including arachidonic acid metabolism, retinol metabolism, and steroid hormone biosynthesis. These findings suggest that TSP could be a promising dietary supplement for protecting the intestinal barrier and alleviating inflammation.

Activation of the endoplasmic reticulum stress regulator IRE1α compromises pulmonary host defenses

The endoplasmic reticulum (ER) stress sensor inositol-requiring enzyme 1α (IRE1α) is associated with lung infections where innate immune cells are drivers for progression and resolution ammatory cytokinesflammation. Yet, the role of IRE1α in pulmonary innate immune host defense during acute respiratory infection remains unexplored. Here, we found that activation of IRE1α in infected lungs compromises immunity against methicillin-resistant Staphylococcus aureus (MRSA)-induced primary and secondary pneumonia. Moreover, activation of IRE1α in MRSA-infected lungs and alveolar macrophages (AMs) leads to exacerbated production of inflammatory mediators followed by cell death. Ablation of myeloid IRE1α or global IRE1α inhibition confers protection against MRSA-induced pneumonia with improved survival, bacterial clearance, cytokine reduction, and lung injury. In addition, loss of myeloid IRE1α protects mice against MRSA-induced secondary to influenza pneumonia by promoting AM survival. Thus, activation of IRE1α is detrimental to pneumonia, and therefore, it shows potential as a target to control excessive unresolved lung inflammation.

Annexin A: Cell Death, Inflammation, and Translational Medicine

The annexin superfamily proteins, a family of calcium-dependent phospholipid-binding proteins, are involved in a variety of Ca²+-regulated membrane events. Annexin A, expressed in vertebrates, has been implicated in a variety of regulated cell death (RCD) pathways, including apoptosis, autophagy, pyroptosis, ferroptosis, and neutrophil extracellular trap-induced cell death (NETosis). Given that inflammation is a key driver of cell death, the roles of Annexin A in inflammation have been extensively studied. In this review, we discuss the regulatory roles of Annexin A in RCD and inflammation, the development of related targeted therapies in translational medicine, and the application of animal models to study these processes. We also analyze current challenges and discuss future directions for improved diagnostic and therapeutic strategies.

Astrocytic lipid droplets contain MHCII and may act as cogs in the antigen presentation machinery

Lipid droplets (LDs) are crucial for energy homeostasis, but are also involved in a wide spectrum of other cellular processes. Accumulating data identifies LDs as an important player in inflammation. However, the underlying mechanisms and the impact of LDs on neuroinflammation remain unclear. Here, we describe a novel function of LDs in human astrocytes, in the context of Alzheimer's disease (AD). Although, the overall lipid profile was unchanged in astrocytes with AD pathology, our data show a clear effect on LD metabolism and specific fatty acids involved in neuroinflammation. Importantly, we found astrocytes to be in close contact with infiltrating CD4 + T cells in the AD brain. Moreover, PLIN3 + LDs in astrocytes co-localize with major histocompatibility complex II (MHCII), indicating a role of LDs in adaptive immunity. Comprehensive analysis of human induced pluripotent stem cell (hiPSC)-derived astrocytes revealed that MHCII is in fact loaded within PLIN3 + LDs and forwarded to neighboring cells via tunneling nanotubes and secretion. Notably, the MHCII molecules are cleaved into its active form prior to packing, indicating an alternative route of MHCII shuttling through LDs, transporting functional immune complexes between cells. Quantification of PLIN3 + LDs in astrocytic cultures, human brain tissue and cerebral organoids indicates that AD pathology initially stimulates PLIN3 + LD formation, but in the long-run results in PLIN3 + LD consumption, which may have consequences on the astrocytes' MHCII distribution capacity. Taken together, our findings present a novel function of PLIN3 + LDs that can be of relevance for AD and other inflammatory conditions.

Identification of cellular senescence-related genes as biomarkers for lupus nephritis based on bioinformatics

Background

Lupus nephritis (LN) is one of the most common and severe complications of systemic lupus erythematosus with unclear pathogenesis. The most accurate diagnosis criterion of LN is still renal biopsy and nowadays treatment strategies of LN are far from satisfactory. Cellular senescence is defined as the permanent cell cycle arrest marked by senescence-associated secretory phenotype (SASP), which has been proved to accelerate the mobility and mortality of patients with LN. The study is aimed to identify cellular senescence-related genes for LN.

Methods

Genes related to cellular senescence and LN were obtained from the MSigDB genetic database and GEO database respectively. Through differential gene analysis, Weighted Gene Go-expression Network Analysis (WGCNA) and machine learning algorithms, hub cellular senescence-related differentially expressed genes (CS-DEGs) were identified. By external validation, hub CS-DEGs were further filtered and the remaining genes were identified as biomarkers. We explored their potential physiopathologic function through GSEA.

Results

We obtained 432 genes related to cellular senescence, 1,208 differentially expressed genes (DEGs) and 840 genes in the key gene module related to LN, which were intersected with each other for CS-DEGs. Subsequent Machine learning algorithms screened out six hub CS-DEGs and finally three hub CS-DEGs, ALOX5, PTGER2 and PRKCB passed through external validation, which were identified as biomarkers. The three biomarkers were enriched in "B Cell receptor signaling pathway" and "NF-kappa B signaling pathway" based on GESA results.

Conclusion

This study explored the potential relationship between cellular senescence and LN, and identified three biomarkers ALOX5, PTGER2, and PRKCB playing key roles in LN, which will provide new insights for the diagnosis and treatment of LN.

Elevated Levels of IL-1Ra, IL-1β, and Oxidative Stress in COVID-19: Implications for Inflammatory Pathogenesis

Background: The coronavirus-caused disease (COVID-19), first identified in China in December 2019, has spread worldwide becoming a global pandemic. Although people infected with the SARS-CoV-2 virus presented mainly respiratory and gastrointestinal symptoms, an increase in cardiovascular incidents was observed in several scientific studies. SARS-CoV-2 virus has been shown to disrupt the normal immune response leading to a dysregulation of immune system function and massive production of inflammatory cytokines commonly known as "cytokine storm". Methods: 57 patients eventually participated in the study, assigned to non-COVID (24 patients) and COVID (33 patients) groups. After signing consent to participate in the study, each patient was given a self-administered questionnaire to fill out prior to specimen collection, anthropometric measurements were taken and venous blood was collected for the following determinations: pro- and anti-inflammatory cytokines using a Bio-Plex 200 system, oxidative stress markers and basic hematological blood parameters. Results: showed statistically significant higher values of IL-1Ra and IL-1β in the COVID-19 group. Of the oxidative stress markers, only MDA levels were higher in the COVID-19 group. Conclusions: the results of our study provide evidence and support the occurrence of elevated levels of IL-1Ra, IL-1β and MDA in the COVID-19 group of patients, which are associated with a worse course and prognosis of COVID-19. A better understanding of the pathophysiology and dysregulation of the immune system associated with the cytokine storm is essential to select patients at risk and develop effective drugs and vaccines.

Species-specific optimization of oxylipin ionization in LC-MS: a design of experiments approach to improve sensitivity

Oxylipins are diverse bioactive signaling molecules, which occur in very low concentrations in complex matrices, posing challenges in achieving consistent and sensitive analysis. UHPLC-MS/MS is the preferred technique to separate and quantify these molecules, often optimized using a time-consuming trial-and-error approach. In this study, we applied the design of experiments (DoE) approach to systematically investigate the ionization properties of multiple oxylipin species. Fractional factorial and central composite designs were employed to detect relevant instrument parameters and optimize signal intensity in ESI-MS/MS analysis. Response surface modeling revealed distinct ionization and fragmentation behaviors between polar and apolar oxylipins, driven by their responses to interface temperature and collision-induced dissociation (CID) gas pressure. Particularly, prostaglandins and lipoxins benefit from higher CID gas pressure and lower temperatures compared to the lipophilic HODEs and HETEs to achieve optimal intensity in multiple reaction monitoring analysis. While global source parameters were optimized, analyte-specific entrance/exit potentials and collision energies required individual adjustments. The final method was applied to analyze seven oxylipin classes including leukotrienes, prostaglandins, lipoxins, resolvins, HETEs, HODES, and HoTrEs. Although improvements in lower limits of quantification were modest (< 1 pg on-column), signal-to-noise ratios increased two-fold for lipoxins and resolvins and three- to four-fold for leukotrienes and HETEs, enhancing detection at trace levels. This DoE-guided strategy provides a powerful tool to improve UHPLC-MS/MS analysis of oxylipins across various instrument vendors, guiding the way towards inter-laboratory comparability.

Immunoregulatory mechanisms of the arachidonic acid pathway in cancer

The arachidonic acid (AA) pathway promotes tumor progression by modulating the complex interactions between cancer and immune cells within the microenvironment. In this Review, we summarize the knowledge acquired thus far concerning the intricate mechanisms through which eicosanoids either promote or suppress the antitumor immune response. In addition, we will discuss the impact of eicosanoids on immune cells and how they affect responsiveness to immunotherapy, as well as potential strategies for manipulating the AA pathway to improve anticancer immunotherapy. Understanding the molecular pathways and mechanisms underlying the role played by AA and its metabolites in tumor progression may contribute to the development of more effective anticancer immunotherapies.

Lipidomic insights on abdominal aortic aneurysm and peripheral arterial disease

Abdominal aortic aneurysm (AAA) and peripheral arterial disease (PAD) are two cardiovascular diseases associated with considerable morbidity, mortality and quality of life impairment. As they are multifactorial diseases, several factors contribute to their pathogenesis, including oxidative stress and lipid peroxidation, and these may have key roles in the development of these pathologies. Alterations of the lipid metabolism and lipid profile have been reported in cardiovascular diseases but to a lesser extent in AAA and PAD. Modifications in the profile of some molecular lipid species, in particular, native phospholipid and triglyceride species were mainly reported for AAA, while alterations in the fatty acid profile were noticed in the case of PAD. Oxidized phospholipids were also reported for AAA. Although AAA and PAD have a common atherosclerotic root, lipidomics demonstrates the existence of distinct lipid. Lipidomic research regarding AAA and PAD is still scarce and should be set in motion to increase the knowledge on the lipid changes that occur in these diseases, contributing not only to the discovery of new biomarkers for diagnosis and prognosis assessment but also to tailor precision medicine in the clinical field.

Arachidonic acid in aging: New roles for old players

BACKGROUND

Arachidonic acid (AA), one of the most ubiquitous polyunsaturated fatty acids (PUFAs), provides fluidity to mammalian cell membranes. It is derived from linoleic acid (LA) and can be transformed into various bioactive metabolites, including prostaglandins (PGs), thromboxanes (TXs), lipoxins (LXs), hydroxy-eicosatetraenoic acids (HETEs), leukotrienes (LTs), and epoxyeicosatrienoic acids (EETs), by different pathways. All these processes are involved in AA metabolism. Currently, in the context of an increasingly visible aging world population, several scholars have revealed the essential role of AA metabolism in osteoporosis, chronic obstructive pulmonary disease, and many other aging diseases.

AIM OF REVIEW

Although there are some reviews describing the role of AA in some specific diseases, there seems to be no or little information on the role of AA metabolism in aging tissues or organs. This review scrutinizes and highlights the role of AA metabolism in aging and provides a new idea for strategies for treating aging-related diseases.

KEY SCIENTIFIC CONCEPTS OF REVIEW

As a member of lipid metabolism, AA metabolism regulates the important lipids that interfere with the aging in several ways. We present a comprehensivereviewofthe role ofAA metabolism in aging, with the aim of relieving the extreme suffering of families and the heavy economic burden on society caused by age-related diseases. We also collected and summarized data on anti-aging therapies associated with AA metabolism, with the expectation of identifying a novel and efficient way to protect against aging.

Conformational dynamics and activation of membrane-associated human Group IVA cytosolic phospholipase A 2 (cPLA 2 )

Cytosolic phospholipase A 2 (cPLA 2 ) associates with membranes where it hydrolyzes phospholipids containing arachidonic acid to initiate an inflammatory cascade. All-atom molecular dynamics simulations were employed to understand the activation process when cPLA 2 associates with the endoplasmic reticulum (ER) membrane of macrophages where it acts. We found that membrane association causes the lid region of cPLA 2 to undergo a closed-to-open state transition that is accompanied by the sideways movement of loop 495-540, allowing the exposure of a cluster of lysine residues (K488, K541, K543, and K544), which binds the allosteric activator PIP 2 in the membrane. The active site of the open form of cPLA 2 , containing the catalytic dyad residues S228 and D549, exhibited a three-fold larger cavity than the closed form of cPLA 2 in aqueous solution. These findings provide mechanistic insight as to how cPLA 2 ER membrane association promotes major transitions between conformational states critical to allosteric activation and enzymatic phospholipid hydrolysis.

Roles of Lipoxygenases in Cardiovascular Diseases

Lipoxygenases (LOXs) are a family of dioxygenases that catalyze the peroxidation of polyunsaturated fatty acids, such as linoleic acid and arachidonic acid, initiating the synthesis of bioactive lipid mediators. The LOX-mediated production of these bioactive molecules in various cell types plays a critical role in the pathophysiology of cardiovascular diseases, including atherosclerosis, hypertension, and myocardial ischemia-reperfusion injury. In this review, we summarize the roles of LOXs and their products in different cardiovascular cells and conditions, offering valuable insights may contribute to the development of novel therapeutic strategies for cardiovascular diseases.

A Targeted Mass Spectrometric Approach to Evaluate the Anti-Inflammatory Activity of the Major Metabolites of Foeniculum vulgare Mill. Waste in Human Bronchial Epithelium

Fennel waste is rich in compounds that may have beneficial effects on human health. For this reason, the most abundant metabolites in fennel were isolated as the following: quercetin-3-O-glucoside, quinic acid, 1,5-dicaffeoylquinic acid, kaempferol-3-O-glucuronide, and quercetin-3-O-glucuronide. After inducing inflammation in human bronchial epithelial cells by stimulating them with IL-1β, the cells were treated with the specialized Foeniculum vulgare metabolites at different concentrations to assess their anti-inflammatory effect. Eicosanoids, fatty acids, and sphingolipids were extracted from the cell medium and quantified by UPLC-ESI-QTRAP-MS/MS analysis. The anti-inflammatory activity of the metabolites isolated from fennel waste was demonstrated. They were able to alleviate the inflammatory state in human bronchial epithelium by modulating the metabolic expression of both pro- and anti-inflammatory eicosanoids, fatty acids, and sphingolipids. These findings suggest the potential use of fennel waste in the production of dietary supplements to alleviate the symptoms of chronic inflammatory diseases like asthma, chronic obstructive pulmonary disease (COPD), and idiopathic pulmonary fibrosis (IPF), where the continuous use of antiphlogistics may have significant side effects.

Functional characterization of eicosanoid signaling in Drosophila development

20-carbon fatty acid-derived eicosanoids are versatile signaling oxylipins in mammals. In particular, a group of eicosanoids termed prostanoids are involved in multiple physiological processes, such as reproduction and immune responses. Although some eicosanoids such as prostaglandin E2 (PGE2) have been detected in some insect species, molecular mechanisms of eicosanoid synthesis and signal transduction in insects have not been thoroughly investigated. Our phylogenetic analysis indicated that, in clear contrast to the presence of numerous receptors for oxylipins and other lipid mediators in humans, the Drosophila genome only possesses a single ortholog of such receptors, which is homologous to human prostanoid receptors. This G protein-coupled receptor, named Prostaglandin Receptor or PGR, is activated by PGE2 and its isomer PGD2 in Drosophila S2 cells. PGR mutant flies die as pharate adults with insufficient tracheal development, which can be rescued by supplying high oxygen. Consistent with this, through a comprehensive mutagenesis approach, we identified a Drosophila PGE synthase whose mutants show similar pharate adult lethality with hypoxia responses. Drosophila thus has a highly simplified eicosanoid signaling pathway as compared to humans, and it may provide an ideal model system for investigating evolutionarily conserved aspects of eicosanoid signaling.

Immunonutrition in ERAS Protocol for Patients with Gynecologic Cancer: A Narrative Review of the Literature

In-hospital patients who are in the gynecologic oncology setting often suffer from malnutrition, which is one of the primary problems, the rate of which reportedly ranges from 28% to 70%. Malnutrition is a significant risk factor for immunosuppression, negatively impacting immune response and postoperative recovery capacity. At the time of the surgeries, due to their wide scope and aggressive treatments such as chemotherapy and radiotherapy, the situation becomes more serious. Those micronutrients taking part in immunonutrition, namely, arginine, omega-3 fatty acids, nucleotides, and antioxidants, have the potential to prevent inflammation, protect against infections, and promote healing after the surgery. Research has shown that immunonutrition can lower the risk of postoperative infection, promote the normal healing of wounds, and reduce the hospital stays of patients, as well as support malnutrition status during chemotherapy. This review is based on a literature search conducted in Medline, Scopus, Clinicaltrials.gov, Cochrane CENTRAL, and Google Scholar, with the last search date being November 2024. Some studies. found that perioperative immunonutrition decreases wound infections and affects some immune indexes in gynecologic oncology patients positively. However, factors such as non-compliant patients, high costs, and non-standard formulations can deter its wider use. Patient adherence drops postoperatively mainly due to nausea and decreased appetite, whereas the cost of enriched formulations acts as an economic barrier. Postoperative compliance drops from ~78% prior to surgery to ~28% due to nausea, anorexia, and chemotherapy. Additionally, cost remains a constraining factor since special formulas are 2-4 times that of normal nutrition. While immunonutrition reduces hospital stay (by ~2-3 days) and infection rate (by 25-40%), access is hindered by prohibitive initial costs and lack of insurance coverage. Approaches such as subsidized schemes, enhanced palatability, and cost-benefit analyses are required to increase adoption. In addition, the lack of standardized protocols makes the clinical community hesitant to adopt this approach. Immunonutrition is, despite these problems, still hoped to be the new adjunct to gynecologic oncology patients. In future studies, it is imperative to pay attention to the best formulations that produce the best outcomes and evaluate and implement guidelines that are based on evidence. Together, with these improvements, immunonutrition could very well be an integral part of perioperative care thus completing the process by which patients in intense treatments are benefited not only via treatment but also via quality of life.

Nannochloropsis Lipids and Polyunsaturated Fatty Acids: Potential Applications and Strain Improvement

The genus Nannochloropsis comprises a group of oleaginous microalgae that accumulate polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA). These molecules are essential for the correct development and health of humans and animals. Thanks to their attractive lipid profile, Nannochloropsis is mainly marketed as a feed ingredient in aquaculture. In microalgae of this genus, contents and cellular location of PUFAs are affected by the growth conditions and gene expression. Strain improvement through non-recombinant approaches can generate more productive strains and efficient bioprocesses for PUFA production. Nevertheless, the lack of specific markers, detection methods, and selective pressure for isolating such mutants remains a bottleneck in classical mutagenesis approaches or lipid quality assessment during cultivation. This review encompasses the importance of PUFAs and lipid classes from Nannochloropsis species and their potential applications. Additionally, a revision of the different ways to increase PUFA content in Nannochloropsis sp. by using classical mutagenesis and adaptive laboratory evolution is also presented, as well as various methods to label and quantify lipids and PUFAs from Nannochloropsis microalgae.

How pathogens drive adipose tissue loss in the host

Weight loss is a hallmark of many infections, including those caused by bacteria, fungi and parasites. This loss is often attributed to infection-induced anorexia and the need to mobilise energy from internal sources to cope with the pathogens. Weight loss during infection results from a significant reduction of muscle and fat mass, two organs that together account for approximately 60% of body mass in the healthy state. While muscle wasting is a well-documented aspect of infection-related weight loss, adipose tissue loss via lipolysis also plays a critical role and can determine disease outcomes. This review explores the regulators of adipose tissue depletion via excessive lipolysis during infection, the probable mechanisms, and the potential consequences for host survival and pathogen fitness.

Identification and verification of biomarkers associated with arachidonic acid metabolism in non-alcoholic fatty liver disease

Elevated arachidonic acid metabolism (AAM) has been linked to the progression of non-alcoholic fatty liver disease (NAFLD). However, the specific role of AAM-related genes (AAMRGs) in NAFLD remains poorly understood. To investigate the involvement of AAMRGs in NAFLD, this study analyzed datasets GSE89632 and GSE135251 from the Gene Expression Omnibus (GEO) and Molecular Signatures Database (MSigDB). Differential expression analysis revealed 2256 differentially expressed genes (DEGs) between NAFLD and control liver tissues. Cross-referencing these DEGs with AAMRGs identified nine differentially expressed AAMRGs (DE-AAMRGs). Least absolute shrinkage and selection operator (LASSO) and univariate logistic regression analyses pinpointed five biomarkers-CYP2U1, GGT1, PLA2G1B, GPX2, and PTGS1-demonstrating significant diagnostic potential for NAFLD, as validated by receiver operating characteristic (ROC) analysis. These biomarkers were implicated in pathways related to AAM and arachidonate transport. An upstream regulatory network, involving transcription factors (TFs) and MicroRNAs (miRNAs), was constructed to explore the regulatory mechanisms of these biomarkers. In vivo validation using a NAFLD mouse model revealed liver histopathological changes, and quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot (WB) analyses confirmed the upregulation of biomarker expression, particularly PTGS1, in NAFLD. The bioinformatic analysis identified five AAM-related biomarkers, enhancing the understanding of NAFLD pathogenesis and offering potential diagnostic targets.

ATP Alters the Oxylipin Profiles in Astrocytes: Modulation by High Glucose and Metformin

Background: Astrocytes play a key role in the inflammatory process accompanying various neurological diseases. Extracellular ATP accompanies inflammatory processes in the brain, but its effect on lipid mediators (oxylipins) in astrocytes remains elusive. Metformin is a hypoglycemic drug with an anti-inflammatory effect that has been actively investigated in the context of therapy for neuroinflammation, but its mechanisms of action are not fully elucidated. Therefore, we aimed to characterize the effects of ATP on inflammatory markers and oxylipin profiles; determine the dependence of these effects on the adaptation of astrocytes to high glucose levels; and evaluate the possibility of modulating ATP effects using metformin. Methods: We estimated the ATP-mediated response of primary rat astrocytes cultured at normal (NG, 5 mM) and high (HG, 22.5 mM) glucose concentrations for 48 h before stimulation. Cell responses were assessed by monitoring changes in the expression of inflammatory markers (TNFα, IL-6, IL-10, IL-1β, iNOS, and COX-2) and the synthesis of oxylipins (41 compounds), assayed with ultra-high-performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS). Intracellular pathways were assessed by analyzing the phosphorylation of p38; ERK MAPK; transcription factors STAT3 and NF-κB; and the enzymes mediating oxylipin synthesis, COX-1 and cPLA2. Results: The stimulation of cells with ATP does not affect the expression of pro-inflammatory markers, increases the activities of p38 and ERK MAPKs, and activates oxylipin synthesis, shifting the profiles toward an increase in anti-inflammatory compounds (PGD2, PGA2, 12-HHT, and 18-HEPE). The ATP effects are reduced in HG astrocytes. Metformin potentiated ATP-induced oxylipin synthesis (11-HETE, PGD2, 12-HHT, 15-HETE, 13-HDoHE, and 15-HETrE), which was predominantly evident in NG cells. Conclusions: Our data provide new evidence showing that ATP induces the release of anti-inflammatory oxylipins, and metformin enhances these effects. These results should be considered in the development of anti-inflammatory therapeutic approaches aimed at modulating astrocyte function in various pathologies.

Mechanisms of immunity in acutely decompensated cirrhosis and acute-on-chronic liver failure

The identification of systemic inflammation (SI) as a central player in the orchestration of acute-on-chronic liver failure (ACLF) has opened new avenues for the understanding of the pathophysiological mechanisms underlying this disease condition. ACLF, which develops in patients with acute decompensation of cirrhosis, is characterized by single or multiple organ failure and high risk of short-term (28-day) mortality. Its poor outcome is closely associated with the severity of the systemic inflammatory response. In this review, we describe the key features of SI in patients with acutely decompensated cirrhosis and ACLF, including the presence of a high blood white cell count and increased levels of inflammatory mediators in systemic circulation. We also discuss the main triggers (i.e. pathogen- and damage-associated molecular patterns), the cell effectors (i.e. neutrophils, monocytes and lymphocytes), the humoral mediators (acute phase proteins, cytokines, chemokines, growth factors and bioactive lipid mediators) and the factors that influence the systemic inflammatory response that drive organ failure and mortality in ACLF. The role of immunological exhaustion and/or immunoparalysis in the context of exacerbated inflammatory responses that predispose ACLF patients to secondary infections and re-escalation of end-organ dysfunction and mortality are also reviewed. Finally, several new potential immunogenic therapeutic targets are debated.

A plasma lipid signature in acute human traumatic brain injury: Link with neuronal injury and inflammation markers

Traumatic brain injury (TBI) leads to major membrane lipid breakdown. We investigated plasma lipids over 3 days post-TBI, to identify a signature of acute human TBI and assess its correlation with neuronal injury and inflammation. Plasma from patients with TBI (Abbreviated Injury Scale (AIS)3 - serious injury, n = 5; AIS4 - severe injury, n = 8), and controls (n = 13) was analysed for lipidomic profile, neurofilament light (NFL) and cytokines, and the omega-3 index was measured in red blood cells. A lipid signature separated TBI from controls, at 24 and 72 h. Major species driving the separation were: lysophosphatidylcholine (LPC), phosphatidylcholine (PC) and hexosylceramide (HexCer). Docosahexaenoic acid (DHA, 22:6) and LPC (0:0/22:6) decreased post-injury. NFL levels were increased at 24 and 72 h post-injury in AIS4 TBI vs. controls. Interleukin (IL-)6, IL-2 and IL-13 were elevated at 24 h in AIS4 patients vs. controls. NFL and IL-6 were negatively correlated with several lipids. The omega-3 index at admission was low in all patients (controls: 4.3 ± 1.1% and TBI: 4.0 ± 1.1%) and did not change significantly over 3 days post-injury. We have identified specific lipid changes, correlated with markers of injury and inflammation in acute TBI. These observations could inform future lipid-based therapeutic approaches.

Beyond CCR7: dendritic cell migration in type 2 inflammation

Conventional dendritic cells (cDCs) are crucial antigen-presenting cells that initiate and regulate T cell responses, thereby shaping immunity against pathogens, innocuous antigens, tumors, and self-antigens. The migration of cDCs from peripheral tissues to draining lymph nodes (dLNs) is essential for their function in immune surveillance. This migration allows cDCs to convey the conditions of peripheral tissues to antigen-specific T cells in the dLNs, facilitating effective immune responses. Migration is primarily mediated by chemokine receptor CCR7, which is upregulated in response to homeostatic and inflammatory cues, guiding cDCs to dLNs. However, during type 2 immune responses, such as those triggered by parasites or allergens, a paradox arises-cDCs exhibit robust migration to dLNs despite low CCR7 expression. This review discusses how type 2 inflammation relies on additional signaling pathways, including those induced by membrane-derived bioactive lipid mediators like eicosanoids, sphingolipids, and oxysterols, which cooperate with CCR7 to enhance cDC migration and T helper 2 (Th2) differentiation. We explore the potential regulatory mechanisms of cDC migration in type 2 immunity, offering insights into the differential control of cDC trafficking in diverse immune contexts and its impact on immune responses.

Resveratrol in animal models of pancreatitis and pancreatic cancer: A systematic review with machine learning

BACKGROUND

Resveratrol (RES), a common type of plant polyphenols, has demonstrated promising therapeutic efficacy and safety in animal models of pancreatitis and pancreatic cancer. However, a comprehensive analysis of these data is currently unavailable. This study aimed to systematically review the preclinical evidence regarding RES's effects on animal models of pancreatitis and pancreatic cancer via meta-analyses and optimised machine learning techniques.

METHODS

Animal studies published from inception until June 30th 2024, were systematically retrieved and manually filtrated across databases including PubMed, EMBASE, Web of Science, Ovid MEDLINE, Scopus, and Cochrane Library. Methodological quality of the included studies was evaluated following the SYRCLE's RoB tool. Predefined outcomes included histopathology and relevant biochemical parameters for acute pancreatitis, and tumour weight/tumour volume for pancreatic cancer, comparing treatment and model groups. Pooled effect sizes of the outcomes were calculated using STATA 17.0 software. Machine learning techniques were employed to predict the optimal usage and dosage of RES in pancreatitis models.

RESULTS

A total of 50 studies comprising 33 for acute pancreatitis, 1 chronic pancreatitis, and 16 for pancreatic cancer were included for data synthesis after screening 996 records. RES demonstrated significant improvements on pancreatic histopathology score, pancreatic function parameters (serum amylase and lipase), inflammatory markers (TNF-α, IL-1β, IL-6, and pancreatic myeloperoxidase), oxidative biomarkers (malondialdehyde and superoxide dismutase), and lung injury (lung histopathology and myeloperoxidase) in acute pancreatitis models. In pancreatic cancer models, RES notably reduced tumour weight and volume. Machine learning highlighted tree-structured Parzen estimator-optimised gradient boosted decision tree model as achieving the best performance, identifying course after disease induction, total dosage, single dosage, and total number of doses as critical factors for improving pancreatic histology. Optimal single dosage was 20-105 mg/kg with 3 to 9 doses.

CONCLUSION

This study comprehensively demonstrates the therapeutic effects of RES in mitigating pancreatitis and pancreatic cancer in animal models. Anti-inflammatory, anti-oxidative, and anti-tumour growth properties are potential mechanisms of action for RES.

Consumer Product Chemical Mixtures and Oxylipin-Mediated Inflammation and Oxidative Stress during Early Pregnancy: Findings from a Large US Pregnancy Cohort

Consumer product chemicals pose an environmental risk to public health. Exposure during pregnancy to consumer product chemicals, particularly phthalates and phenols, may increase the susceptibility to pregnancy disorders by dysregulating inflammation and oxidative stress. However, existing studies rely on downstream and nonmodifiable markers of these processes. Oxylipins are oxidized lipids that act as key upstream drivers of inflammation and oxidative stress. Importantly, oxylipins are responsive to therapeutic interventions and thus potentially modifiable. Using recent advances in lipidomics and statistical approaches to address both individual chemical biomarkers and their mixtures, we determined associations between early pregnancy biomarkers of consumer product chemical exposure and oxylipins in a large prospective cohort. Overall, our results revealed associations among oxylipins produced across several biosynthetic pathways, suggesting a pattern indicative of dysregulated inflammation and elevated levels of oxidative stress. Phthalate metabolites were the primary drivers of associations, particularly for metabolites of low molecular weight phthalates, often used in personal care products. However, we found similar associations for a biomarker of a phthalate replacement that is increasingly used in consumer products. Our study provides observational evidence of specific physiological pathways that may be dysregulated by exposure to consumer product chemicals, including legacy phthalates and phthalate replacements.

Bioactive lipid signaling and lipidomics in macrophage polarization: Impact on inflammation and immune regulation

Macrophages, crucial innate immune cells, defend against pathogens and resolve inflammation, maintaining tissue balance. They perform phagocytosis, present antigens to T cells, and bond innate and adaptive immunity through various activation states. Classical activation is associated with Th1 responses and interferon γ production, while alternative activation, induced by interleukin 4, is characterized by increased endocytosis, reduced secretion of pro-inflammatory cytokines, and roles in immunoregulation and tissue remodeling. Although these represent opposite extremes observed in vitro, the remarkable plasticity of macrophages allows for a wide spectrum of activation phenotypes that are complex to characterize experimentally. While the application of omics techniques has resulted in significant advances in the characterization of macrophage polarization, lipidomic studies have received lesser attention. Beyond their role as structural components and energy sources, lipids function as signaling molecules that regulate macrophage activation and polarization, thereby shaping immune responses. This work reviews the interaction between lipid signaling and macrophage polarization, exploring how lipid metabolism influences macrophage phenotype and function. These insights offer potential therapeutic strategies for immune-mediated diseases and inflammation-related disorders, including inflammaging.

Revealing rutaecarpine's promise: A pathway to parkinson's disease relief through PPAR modulation

The pathological mechanisms of Parkinson's disease (PD) is complex, and no definitive cure currently exists. This study identified Rutaecarpine (Rut), an alkaloid extracted from natural plants, as a potential therapeutic agent for PD. To elucidate its mechanisms of action and specific effects in PD, network pharmacology, molecular docking, and experimental validation methods were employed. Our findings demonstrated the efficacy of Rut in ameliorating PD symptoms. Network pharmacology analysis indicated that Rut exerts its therapeutic effects through the PPAR signaling pathway and the lipid pathway. Molecular docking results revealed that Rut forms stable protein-ligand complexes with PPARα and PPARγ. Animal experiments showed that Rut improved motor function in PD mice, protected dopaminergic neurons, ameliorated lipid metabolism disorders, and reduced neuroinflammation. This study identified the critical molecular mechanisms and therapeutic targets of Rut in the treatment of PD, providing a theoretical foundation for future investigations into the pharmacodynamics of Rut as a potential anti-PD agent.

ATP-release pannexin channels are gated by lysophospholipids

In addition to its role as cellular energy currency, adenosine triphosphate (ATP) serves as an extracellular messenger that mediates diverse cell-to-cell communication. Compelling evidence supports that ATP is released from cells through pannexins, a family of membrane proteins that form heptameric large-pore channels. However, the activation mechanisms that trigger ATP release by pannexins remain poorly understood. Here, we discover lysophospholipids as endogenous pannexin activators, using activity-guided fractionation of mouse tissue extracts combined with untargeted metabolomics and electrophysiology. We show that lysophospholipids directly and reversibly activate pannexins in the absence of other proteins. Secretomics experiments reveal that lysophospholipid-activated pannexin 1 leads to the release of not only ATP but also other signaling metabolites, such as 5'-methylthioadenosine, which is important for immunomodulation. We also demonstrate that lysophospholipids activate endogenous pannexin 1 in human monocytes, leading to the release of IL-1β through inflammasome activation. Our results provide a connection between lipid metabolism and purinergic signaling, both of which play major roles in immune responses.

Gangliosides and Cholesterol: Dual Regulators of Neuronal Membrane Framework in Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with heterogeneous clinical presentation. Diagnosing ASD is complex, and the criteria for diagnosis, as well as the term ASD, have changed during the last decades. Diagnosis is made based on observation and accomplishment of specific diagnostic criteria, while a particular biomarker of ASD does not yet exist. However, studies universally report a disequilibrium in membrane lipid content, pointing to a unique neurolipid signature of ASD. This review sheds light on the possible role of cholesterol and gangliosides, complex membrane glycosphingolipids, in the development of ASD. In addition to maintaining membrane integrity, neuronal signaling, and synaptic plasticity, these lipids play a role in neurotransmitter release and calcium signaling. Evidence linking ASD to lipidome changes includes low cholesterol levels, unusual ganglioside levels, and unique metabolic profiles. ASD symptoms may be mitigated with therapeutic interventions targeting the lipid composition of membranes. However, restoring membrane equilibrium in the central nervous system remains a challenge. This review underscores the need for comprehensive research into lipid metabolism to uncover practical insights into ASD etiology and treatment as lipidomics emerges as a major area in ASD research.

Systematic review of innate immune responses against Mycobacterium tuberculosis complex infection in animal models

Background

Mycobacterium tuberculosis (Mtb) complex (MTBC) includes ten species that affect mammals and pose a significant global health concern. Upon infection, Mtb induces various stages in the host, including early bacterial elimination, which may or may not involve memory responses. Deciphering the role of innate immune responses during MTBC infection is crucial for understanding disease progression or protection. Over the past decade, there has been growing interest in the innate immune response to Mtb, with new preclinical models emerging.

Methods

We conducted a systematic review following PRISMA guidelines, focused on innate immune mediators linked to protection or disease progression in animal models of MTBC infection. We searched two databases: National Library of Medicine and Web of Science. Two researchers independently extracted data based on specific inclusion and exclusion criteria.

Results

Eighty-three articles were reviewed. Results were categorized in four groups: MTBC species, animal models, soluble factors and innate pathways, and other molecules (metabolites and drugs). Mtb and M. bovis were the only species studied. P2X7R receptor's role in disease progression and higher macrophage recruitment were observed differentially after infection with hypervirulent Mtb strains. Mice and non-human primates (NHPs) were the most used mammals, with emerging models like Galleria mellonella and planarians also studied. NHPs provided insights into age-dependent immunity and markers for active tuberculosis (ATB). Key innate immune factors/pathways identified included TNF-α, neutrophil recruitment, ROS/RNS responses, autophagy, inflammasomes, and antimicrobial peptides, with homologous proteins identified in insects. Metabolites like vitamin B5 and prostaglandin E2 were associated with protection. Immunomodulatory drugs targeting autophagy and other mechanisms were studied, exhibiting their potential as therapeutic alternatives.

Conclusion

Simpler, physiologically relevant, and ethically sound models, such as G. mellonella, are needed for studying innate responses in MTBC infection. While insects lack adaptive immunity, they could provide insights into "pure" innate immune responses. The dissection of "pure," "sustained" (later than 7 days post-infection), and trained innate immunity presents additional challenges that require high-resolution temporospatial analytical methods. Identifying early innate immune mediators and targetable pathways in the blood and affected tissues could identify biomarkers for immunization efficiency, disease progression, and potential synergistic therapies for ATB.

msiFlow: automated workflows for reproducible and scalable multimodal mass spectrometry imaging and microscopy data analysis

Multimodal imaging by matrix-assisted laser desorption ionisation mass spectrometry imaging (MALDI MSI) and microscopy holds potential for understanding pathological mechanisms by mapping molecular signatures from the tissue microenvironment to specific cell populations. However, existing software solutions for MALDI MSI data analysis are incomplete, require programming skills and contain laborious manual steps, hindering broadly applicable, reproducible, and high-throughput analysis to generate impactful biological discoveries. Here, we present msiFlow, an accessible open-source, platform-independent and vendor-neutral software for end-to-end, high-throughput, transparent and reproducible analysis of multimodal imaging data. msiFlow integrates all necessary steps from raw data import to analytical visualisation along with state-of-the-art and self-developed algorithms into automated workflows. Using msiFlow, we unravel the molecular heterogeneity of leukocytes in infected tissues by spatial regulation of ether-linked phospholipids containing arachidonic acid. We anticipate that msiFlow will facilitate the broad applicability of MSI in multimodal imaging to uncover context-dependent cellular regulations in disease states.

Microbial adaptive pathogenicity strategies to the host inflammatory environment

Pathogenic microorganisms can infect a variety of niches in the human body. During infection, these microbes can only persist if they adapt adequately to the dynamic host environment and the stresses imposed by the immune system. While viruses entirely rely on host cells to replicate, bacteria and fungi use their pathogenicity mechanisms for the acquisition of essential nutrients that lie under host restriction. An inappropriate deployment of pathogenicity mechanisms will alert host defence mechanisms that aim to eradicate the pathogen. Thus, these adaptations require tight regulation to guarantee nutritional access without eliciting strong immune activation. To work efficiently, the immune system relies on a complex signalling network, involving a myriad of immune mediators, some of which are quite directly associated with imminent danger for the pathogen. To manipulate the host immune system, viruses have evolved cytokine receptors and viral cytokines. However, among bacteria and fungi, selected pathogens have evolved the capacity to use these inflammatory response-specific signals to regulate their pathogenicity. In this review, we explore how bacterial and fungal pathogens can sense the immune system and use adaptive pathogenicity strategies to evade and escape host defence to ensure their persistence in the host.

Lipid droplets in central nervous system and functional profiles of brain cells containing lipid droplets in various diseases

Lipid droplets (LDs), serving as the convergence point of energy metabolism and multiple signaling pathways, have garnered increasing attention in recent years. Different cell types within the central nervous system (CNS) can regulate energy metabolism to generate or degrade LDs in response to diverse pathological stimuli. This article provides a comprehensive review on the composition of LDs in CNS, their generation and degradation processes, their interaction mechanisms with mitochondria, the distribution among different cell types, and the roles played by these cells-particularly microglia and astrocytes-in various prevalent neurological disorders. Additionally, we also emphasize the paradoxical role of LDs in post-cerebral ischemia inflammation and explore potential underlying mechanisms, aiming to identify novel therapeutic targets for this disease.

Genome-wide association study reveals shared and distinct genetic architecture of fatty acids and oxylipins in the Hispanic Community Health Study/Study of Latinos

Bioactive fatty acid-derived oxylipin molecules play key roles mediating inflammation and oxidative stress. Circulating levels of fatty acids and oxylipins are influenced by environmental and genetic factors; characterizing the genetic architecture of bioactive lipids could yield new insights into underlying biology. We performed a genome-wide association study (GWAS) of 81 fatty acids and oxylipins in 11,584 Hispanic Community Health Study/Study of Latinos (HCHS/SOL) participants with genetic and lipidomic data measured at study baseline (58.6% female, mean age = 46.1 years (standard deviation 13.8)). Additionally, given the effects of central obesity on inflammation, we examined interactions with waist circumference using two-degree-of-freedom joint tests. Thirty-three of the 81 oxylipins and fatty acids were significantly heritable (heritability range: 0-32.7%). Forty (49.4%) oxylipins and fatty acids had at least one genome-wide significant (p < 6.94E-11) variant resulting in 19 independent genetic loci. Six loci (lead variant minor allele frequency [MAF] range: 0.08-0.50), including desaturase-encoding FADS and OATP1B1 transporter protein-encoding SLCO1B1, exhibited associations with two or more fatty acids and oxylipins. At several of these loci, there was evidence of colocalization of the top variant across fatty acids and oxylipins. The remaining loci were only associated with one oxylipin or fatty acid and included several CYP loci. We also identified an additional rare variant (MAF = 0.002) near CARS2 in two-degree-of-freedom tests. Our analyses revealed shared and distinct genetic architecture underlying fatty acids and oxylipins, providing insights into genetic factors and motivating work to characterize these compounds and elucidate their roles in disease.

The Octadecanoids: Synthesis and Bioactivity of 18-Carbon Oxygenated Fatty Acids in Mammals, Bacteria, and Fungi

The octadecanoids are a broad class of lipids consisting of the oxygenated products of 18-carbon fatty acids. Originally referring to production of the phytohormone jasmonic acid, the octadecanoid pathway has been expanded to include products of all 18-carbon fatty acids. Octadecanoids are formed biosynthetically in mammals via cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP) activity, as well as nonenzymatically by photo- and autoxidation mechanisms. While octadecanoids are well-known mediators in plants, their role in the regulation of mammalian biological processes has been generally neglected. However, there have been significant advancements in recognizing the importance of these compounds in mammals and their involvement in the mediation of inflammation, nociception, and cell proliferation, as well as in immuno- and tissue modulation, coagulation processes, hormone regulation, and skin barrier formation. More recently, the gut microbiome has been shown to be a significant source of octadecanoid biosynthesis, providing additional biosynthetic routes including hydratase activity (e.g., CLA-HY, FA-HY1, FA-HY2). In this review, we summarize the current field of octadecanoids, propose standardized nomenclature, provide details of octadecanoid preparation and measurement, summarize the phase-I metabolic pathway of octadecanoid formation in mammals, bacteria, and fungi, and describe their biological activity in relation to mammalian pathophysiology as well as their potential use as biomarkers of health and disease.

Next generation thiazolyl ketone inhibitors of cytosolic phospholipase A2 α for targeted cancer therapy

Eicosanoids are key players in inflammatory diseases and cancer. Targeting their production by inhibiting Group IVA cytosolic phospholipase A2 (cPLA2α) offers a promising approach for cancer therapy. In this study, we synthesize a second generation of thiazolyl ketone inhibitors of cPLA2α starting with compound GK470 (AVX235) and test their in vitro and cellular activities. We identify a more potent and selective lead molecule, GK420 (AVX420), which we test in parallel with AVX235 and a structurally unrelated compound, AVX002 for inhibition of cell viability across a panel of cancer cell lines. From this, we show that activity of polycomb group repressive complex 2 is a key molecular determinant of sensitivity to cPLA2α inhibition, while resistance depends on antioxidant response pathways. Consistent with these results, we show that elevated intracellular reactive oxygen species and activating transcription factor 4 target gene expression precede cell death in AVX420-sensitive T-cell acute lymphoblastic leukemia cells. Our findings imply cPLA2α may support cancer by mitigating oxidative stress and inhibiting tumor suppressor expression and suggest that AVX420 has potential for treating acute leukemias and other cancers that are susceptible to oxidative cell death.

The role of metabolites in the progression of osteoarthritis: Mechanisms and advances in therapy

Osteoarthritis (OA) is a progressive degenerative disease affected by many factors, and there is currently no effective treatment. In recent years, the latest progress in metabolomics in OA research has revealed several metabolic pathways and new specific metabolites involved in OA. Metabolites play significant roles in the identification and management of OA. This review looks back on the development history of metabolomics and the progress of this technology in OA as well as its potential clinical applications. It summarizes the applications of metabolites in the field of OA and future research directions. This understanding will advance the identification of metabolic treatment goals for OA.

The translational potential of this article

The development of metabolomics offers possibilities for the treatment of OA. This article reviews the relationship between metabolites associated with chondrocytes and OA. Selectively altering these three metabolic pathways and their associated metabolites may hold great potential as new focal points for OA treatment.

Molecular Mechanisms Linking Omega-3 Fatty Acids and the Gut-Brain Axis

The gut-brain axis (GBA) is a complex communication network connecting the gastrointestinal tract (GIT) and the central nervous system (CNS) through neuronal, endocrine, metabolic, and immune pathways. Omega-3 (n-3) fatty acids, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are crucial food components that may modulate the function of this axis through molecular mechanisms. Derived mainly from marine sources, these long-chain polyunsaturated fatty acids are integral to cell membrane structure, enhancing fluidity and influencing neurotransmitter function and signal transduction. Additionally, n-3 fatty acids modulate inflammation by altering eicosanoid production, reducing proinflammatory cytokines, and promoting anti-inflammatory mediators. These actions help preserve the integrity of cellular barriers like the intestinal and blood-brain barriers. In the CNS, EPA and DHA support neurogenesis, synaptic plasticity, and neurotransmission, improving cognitive functions. They also regulate the hypothalamic-pituitary-adrenal (HPA) axis by reducing excessive cortisol production, associated with stress responses and mental health disorders. Furthermore, n-3 fatty acids influence the composition and function of the gut microbiota, promoting beneficial bacterial populations abundance that contribute to gut health and improve systemic immunity. Their multifaceted roles within the GBA underscore their significance in maintaining homeostasis and supporting mental well-being.

Anti-Inflammatory, Antithrombotic, and Antioxidant Properties of Amphiphilic Lipid Bioactives from Shrimp

Background/Objectives: Marine organisms, including shrimps, have gained research interest due to containing an abundance of bioactive lipid molecules.This study evaluated the composition and the in vitro biological activities of amphiphilic bioactive compounds from four different wild shrimp species: Litopenaeus vannamei, Penaeus kerathurus, Aristaeomorpha foliacea, and Parapenaeus longirostris. Methods: Total lipid (TL) extracts were obtained from shrimp and separated into total amphiphilic (TAC) and total lipophilic (TLC) compounds. Phenolic (TPC) and carotenoid (TCC) contents, antioxidant activities (DPPH, ABTS, FRAP assays), and biological effects on platelet-activating factor (PAF) and ADP-induced platelet activation were evaluated. Structural analyses were performed using ATR-FTIR spectroscopy, while LC-MS was used to elucidate the fatty acid composition and overall structure of polar lipids (PLs) present in shrimp TAC extracts. Results: TAC extracts, rich in phenolics, carotenoids, PL, and unsaturated fatty acids (UFAs), exhibited stronger anti-inflammatory and antithrombotic activities compared with TLC extracts, which showed potent antioxidant capacity. Significant amounts of UFAs, such as the monounsaturated fatty acid (MUFA) oleic acid (C18:1n9) and omega-3 (n3) polyunsaturated fatty acids (PUFAs) like eicosapentaenoic acid (EPA; C20:5n3) and docosahexaenoic acid (DHA; C22:6n3), were detected in the PLs of shrimp TAC extracts, with favorable anti-inflammatory values for their n6/n3 PUFA ratio. Shrimp amphiphilic bioactives present in the TAC extracts provide anti-inflammatory effects against the PAF pathway and antithrombotic effects against ADP and eicosanoid pathways. Conclusions: The overall findings support further study on the use of shrimp extracts rich in anti-inflammatory, anti-thrombotic, and antioxidant amphiphilic bioactives as ingredients to produce new bio-functional health-promoting products, in the context of sustainable development and circular economy.

The platelet and plasma proteome and targeted lipidome in postpartum dairy cows with elevated systemic inflammation

Unregulated, systemic inflammation negatively impacts health and production in dairy cows. Soluble mediators and platelets have been studied for their expansive role in mediating inflammation. Our objectives were to compare the plasma oxylipin and endocannabinoid profiles, and the platelet and plasma proteomic profiles of healthy cows to cows experiencing elevated systemic inflammation as indicated by plasma haptoglobin (Hp) concentrations. Postpartum cows at 3 DIM with plasma Hp concentrations [Formula: see text] 0.50 g/L and no clinical disease were enrolled into the high-inflammation group (n = 8). Cows with plasma Hp concentrations [Formula: see text] 0.1 g/L and no clinical disease were enrolled into the low-inflammation group (n = 8). Targeted lipidomic analysis revealed differences in the plasma oxylipin and endocannabinoid profile between high- and low-inflammation cows. Cows in the high-inflammation group had increased plasma concentrations of the oxylipins 9(S)-HpOTrE, 9(S)-HOTrE, 13(S)-HpOTrE, and 9,10-EpOME, and the endocannabinoid anandamide. In-depth proteomic analysis of platelets between the high- and low-inflammation groups revealed significant differences in protein categories related to platelet granule release and cellular iron uptake. Proteomic outputs from plasma revealed 24 proteins to be different between high and low-inflammation groups, including proteins involved in autophagy and immune mediation. Together, our results indicate that cows experiencing an exacerbated systemic inflammatory response in the postpartum may have impaired disease resistance, and platelets could be contributors to their inflammatory state.

Palmitic acid inhibits macrophage-mediated chemotherapy resistance in multiple myeloma via ALOX12 signaling

We previously discovered that macrophages (MΦs), especially tumor-associated MΦs (tMΦs), contribute to chemotherapy resistance in multiple myeloma (MM). However, the mechanism underlying MΦ-mediated chemotherapy resistance in MM needs further elucidation, and the identification of factors that preferentially abrogate MΦ-induced inhibition of MM chemotherapy may have important clinical significance. In this study, we showed that the expression of FASN and SCD2, the enzymes that synthesize palmitic acid and convert it to palmitoleic acid, was decreased in tMΦs compared with MΦs. Interestingly, palmitic acid abrogated the MΦ-mediated protection of MM cells from the effects of bortezomib and melphalan in vitro. Combination treatment with palmitic acid and bortezomib or melphalan further inhibited MM tumor growth in vivo. Mechanistically, palmitic acid treatment increased ALOX12 expression in MΦs. ALOX12 inhibition partially abrogated the palmitic acid-induced decrease in MΦ-mediated MM cell survival. Palmitic acid treatment inhibited AMPK signaling in MΦs, and ALOX12 knockdown activated the AMPK signaling pathway in MΦs. AMPK inhibition decreased the MΦ-mediated protection of drug-treated MM cells, and AMPK activation partially abolished the palmitic acid-induced inhibition of MΦ-mediated protection. ALOX12 converts arachidonic acid (AA) to 12-HETE. Moreover, treatment with AA but not 12-HETE partially abrogated the inhibitory effect of palmitic acid on MΦ-mediated MM cell survival in response to bortezomib or melphalan. Overall, we identified palmitic acid as a factor that inhibits MΦ-mediated resistance to bortezomib and melphalan in MM, which may have clinical significance.

Multiomic molecular patterns of lipid dysregulation in a subphenotype of sepsis with higher shock incidence and mortality

BACKGROUND

Lipids play a critical role in defense against sepsis. We sought to investigate gene expression and lipidomic patterns of lipid dysregulation in sepsis.

METHODS

Data from four adult sepsis studies were analyzed and findings were investigated in two external datasets. Previously characterized lipid dysregulation subphenotypes of hypolipoprotein (HYPO; low lipoproteins, increased mortality) and normolipoprotein (NORMO; higher lipoproteins, lower mortality) were studied. Leukocytes collected within 24 h of sepsis underwent RNA sequencing (RNAseq) and shotgun plasma lipidomics was performed.

RESULTS

Of 288 included patients, 43% were HYPO and 57% were NORMO. HYPO patients exhibited higher median SOFA scores (9 vs 5, p = < 0.001), vasopressor use (67% vs 34%, p = < 0.001), and 28-day mortality (30% vs 16%, p = 0.004). Leukocyte RNAseq identified seven upregulated lipid metabolism genes in HYPO (PCSK9, DHCR7, LDLR, ALOX5, PLTP, FDFT1, and MSMO1) vs. NORMO patients. Lipidomics revealed lower cholesterol esters (CE, adjusted p = < 0.001), lysophosphatidylcholines (LPC, adjusted p = 0.001), and sphingomyelins (SM, adjusted p = < 0.001) in HYPO patients. In HYPO patients, DHCR7 expression strongly correlated with reductions in CE, LPC, and SM (p < 0.01), while PCSK9, MSMO1, DHCR7, PLTP, and LDLR upregulation were correlated with low LPC (p < 0.05). DHCR7, ALOX5, and LDLR correlated with reductions in SM (p < 0.05). Mortality and phenotype comparisons in two external datasets (N = 824 combined patients) corroborated six of the seven upregulated lipid genes (PCSK9, DHCR7, ALOX5, PLTP, LDLR, and MSMO1).

CONCLUSION

We identified a genetic lipid dysregulation signature characterized by seven lipid metabolism genes. Five genes in HYPO sepsis patients most strongly correlated with low CE, LPC, and SMs that mediate cholesterol storage and innate immunity.

Baicalin alleviates intestinal inflammation and microbial disturbances by regulating Th17/Treg balance and enhancing Lactobacillus colonization in piglets

BACKGROUND

Intestinal inflammation is a common and serious health problem in piglet production, especially enteritis caused by pathogenic Escherichia coli (E. coli). This condition often leads to high mortality, slow weight gain, and significant economic losses.

RESULTS

In this study, we isolated an E. coli strain, SKLAN202302, from the colon of diarrheal piglets to create an intestinal inflammation model for evaluating the protective effects of baicalin. Piglets infected with E. coli exhibited significant reductions in body weight, feed intake, small intestine length, and ileal goblet cell count (P < 0.05), along with deteriorated ileal morphology. However, baicalin supplementation resulted in body weights, feed intake, and intestinal morphology similar to those of the control group. Notably, there was a significant increase in the colonization of Lactobacillus species, particularly Lactobacillus_reuteri, Lactobacillus_amylovorus, and Lactobacillus_johnii, compared to the E. coli group (P < 0.05). At the metabolic and transcriptional levels, E. coli infection increased inflammatory mediators, including eicosanoids (leukotriene F4, prostaglandin F1a, leukotriene E4, thromboxane B2, prostaglandin G2, and PGH2), monosaccharides, and TCA cycle intermediates (oxoglutaric acid, glutaric acid, adipic acid, citric acid, and isocitric acid) in the ileum. It also promoted the expression of genes related to autoimmune diseases and the Th17 differentiation signaling pathway (CTLA4, IFN-ALPHA-8, IL12RB2, TRAV3, TRAV16, FOS, and VEGFA), as well as inflammatory factors. Conversely, baicalin supplementation not only counteracted these effects but also enhanced the presence of metabolites such as phospholipids [including lysoPC (P-18:1(9Z)/0:0), PC (17:0/0:0), lysoPC (16:1(9Z)/0:0), PC (18:0/0:0), lysoPC (18:0/0:0), PA (10:0/i-16:0), and PA (10:0/8:0)] and amino acids. It also regulated genes within the IL-17 signaling pathway (IL4, CCL17, CXCL10, IFNG, and CXCL2), suggesting a mechanism by which baicalin mitigates E. coli-induced intestinal and microbial disturbances. Subsequent flow cytometry analysis showed that E. coli infection increased the numbers of CD3+ and Foxp3+ cells, decreased IL-17A+ cells, and reduced Th17/Treg ratios. Baicalin supplementation restored these parameters to control levels.

CONCLUSIONS

Baicalin supplementation effectively alleviates E. coli-induced intestinal inflammation and microbial disturbances in piglets by enhancing beneficial Lactobacillus colonization, counteracting inflammatory mediators, and regulating immune-related gene expression and the Th17/Treg balance. These findings highlight baicalin's potential in alleviating intestinal inflammation.

Candidate genes associated with fatty acid compositions in north American Atlantic salmon (Salmo salar)

Fatty acids are a requirement for normal development, however, since humans are unable to de novo produce essential fatty acids, they must be obtained from diet. Atlantic salmon is a major dietary source of nutritious and digestible fatty acids. Here, we set out to uncover the genomic basis of individual fatty acids and indices (saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, n-3, and n-6) in 208 North American Atlantic salmon, to understand selection potential toward increasing relative quantities of essential fatty acids and to identify candidate genes for future research. Total n-6 (pro-inflammatory) was higher than total n-3 (anti-inflammatory) fatty acids with a ratio of 1 : 1.31 (n-3 : n-6). Heritability of fatty acids ranged from 0 to 0.99, however, most fatty acids and indices had moderate to high heritabilities (ranged from 0.20 to 0.88), implying that selection for improvement of traits could be possible. We found the same significant markers on chromosome 23 (based on false discovery rate thresholds of 2.0e-6 and suggestive significant thresholds of 2.0e-5 in Manhattan plots) in four fatty acids (γ-linoleic acid, stearidonic acid, dihimo-γ-linolenic acid, and eicosatrienoic acid), where three genes (sin3b, acbd6, and fads2) are known to be involved in lipid metabolism. These genes, fads2 in particular, would all make ideal candidates for future functional studies. In addition, there were four fatty acids with loci over the suggestive significant threshold with a variety of markers on different chromosomes (lauric acid, stearic acid, eicosatetraenoic acid (ETA), and docosadienoic acid), with associated genes that had relevant functions to fatty acids or adipose cells in general.

Severity-Dependent Long-Term Post-Traumatic Changes in the Circulating Oxylipin Profile

Trauma causes the breakdown of membrane phospholipids and the subsequent degradation of the released polyunsaturated fatty acids (PUFAs) to partially bioactive oxylipins. Here, we screened for circulating PUFAs and oxylipins in patients (n = 34) differing from those of uninjured controls (n = 25) and analyzed their diagnostic potential. Patients were followed up for 1 to 240 h after minor/moderate, severe, and very severe injuries. Of the targeted oxylipins, 13 out of 80 (13/80) were detected in almost all patients and controls. Injury caused a long-term decrease in 9- and 13-hydroxyoctadecadienoic acids and in several dihydroxyeicosatetraenoic acids, the stable derivatives of bioactive anti-inflammatory epoxyeicosatrienoic acids, compared to controls. Frequently, these oxylipins correlated inversely to injury severity, days in the intensive care unit and hospital, and/or procalcitonin and pro-inflammatory cytokine levels 48 up to 240 h after trauma. Notably, 20/80 oxylipins were detected in some patients but not or less often in controls. Many of these oxylipins increased transiently immediately after injury. Their level is partly correlated with adverse clinical parameters at this early time point. The circulating oxylipidome was markedly affected by trauma. Several oxylipins showed injury-dependent alterations at different time points in the post-traumatic course.

Crosstalk and communication of cancer-associated fibroblasts with natural killer and dendritic cells: New frontiers and unveiled opportunities for cancer immunotherapy

Natural killer (NK) cells and dendritic cells (DCs) are critical mediators of anti-cancer immune responses. In addition to their individual roles, NK cells and DCs are involved in intercellular crosstalk which is essential for the initiation and coordination of adaptive immunity against cancer. However, NK cell and DC activity is often compromised in the tumor microenvironment (TME). Recently, much attention has been paid to one of the major components of the TME, the cancer-associated fibroblasts (CAFs), which not only contribute to extracellular matrix (ECM) deposition and tumor progression but also suppress immune cell functions. It is now well established that CAFs support T cell exclusion from tumor nests and regulate their cytotoxic activity. In contrast, little is currently known about their interaction with NK cells, and DCs. In this review, we describe the interaction of CAFs with NK cells and DCs, by secreting and expressing various mediators in the TME of adult solid tumors. We also provide a detailed overview of ongoing clinical studies evaluating the targeting of stromal factors alone or in combination with immunotherapy based on immune checkpoint inhibitors. Finally, we discuss currently available strategies for the selective depletion of detrimental CAFs and for a better understanding of their interaction with NK cells and DCs.

Epithelial-immune interactions govern type 2 immunity at barrier surfaces

Allergic diseases are acute and chronic inflammatory conditions resulting from disproportionate responses to environmental stimuli. Affecting approximately 40% of the global population, these diseases significantly contribute to morbidity and increasing health care costs. Allergic reactions are triggered by pollen, house dust mites, animal dander, mold, food antigens, venoms, toxins, and drugs. This review explores the pivotal role of the epithelium in the skin, lungs, and gastrointestinal tract in regulating the allergic response and delves into the mechanisms of tissue-specific epithelial-immune interactions in this context, with recent advances highlighting their roles in the initiation, elicitation, and resolution phases of allergy. Understanding these intricate interactions at epithelial barriers is essential for developing targeted therapies to manage and treat allergic diseases.

Integrated metabolomics and lipidomics investigation of the mechanism of Danggui Sini Decoction on improving lipid homeostasis in primary dysmenorrhea

BACKGROUND

Danggui Sini Decoction (DGSND) is a classic prescription for treating primary dysmenorrhea (PD), while, the ameliorating effects of DGSND on PD and its mechanisms are not yet fully understood.

PURPOSE

The present study is devoted to investigate the protective effect of DGSND against PD and the possible mechanism from the perspective of metabolomics as well as lipidomics.

METHODS

DGSND was characterized by UPLC-Q-TOF/MS. The PD rat model was induced by estradiol benzoate and oxytocin, and traditional pharmacology, including writhing times, latency time, biochemical index, organ index, and histopathology were performed to evaluated the efficacy of DGSND on PD. Urine metabolomics strategy combined with functional analysis was adopted to delineate the therapeutic effect of DGSND on PD rats and anchor the crucial pathway, and lipidomics analysis was further performed with the uterine tissue as the research object to elucidate the protective mechanism of DGSND from the perspective of lipid homeostasis. Finally, western blot analysis was used to validate the expression of key metabolic enzymes in lipid metabolism.

RESULTS

DGSND was effective in ameliorating writhing times, latency time, the value of prostaglandin F2α (PGF2α)/PGE2, uterus index, and morphological changes of PD rats. Metabolic signature of PD rats was primarily characterized by the disturbance of steroid hormone metabolism, amino acid metabolism, and lipid metabolism. Functional analysis revealed the urine biomarkers of PD were most related with lipid abnormality. Further lipidomics analysis indicated DGSND exerted anti-PD effects by remodeling lipid homeostasis, which might be due to the significant correlations between different kinds of lipids, especially the extremely high correlation of phosphatidylethanolamine, phosphatidylcholine, and fatty acids. Moreover, the key metabolic enzymes expression of CK, PLA2, LPCAT3, COX-2, and 5-LOX can be greatly downregulated by DGSND.

CONCLUSION

Our findings demonstrated a novel protective mechanism of DGSND against PD by regulating lipid homeostasis.