Oleic and linoleic acids promote chondrocyte apoptosis by inhibiting autophagy via downregulation of SIRT1/FOXO1 signaling.

Osteoarthritis (OA) is a complex joint disease that currently has no cure. OA involves metabolic disorders in chondrocytes and an imbalance between autophagy and apoptosis. As a common risk factor for OA, obesity induces changes in the fatty acid composition of synovial fluid, thereby disturbing chondrocyte homeostasis. However, whether unsaturated fatty acids affect the development of OA by regulating chondrocyte autophagy remains unclear. This study aimed to determine the effects of oleic and linoleic acids on chondrocyte autophagy and related mechanisms. Based on the mass spectrometry results, the levels of multiple unsaturated fatty acids, including oleic and linoleic acids, in the synovial fluid of patients with OA and obesity were significantly higher than those in patients with OA only. Moreover, we found that FOXO1 and SIRT1 were downregulated after oleic and linoleic acids treatment of chondrocytes, which inhibited chondrocyte autophagy. Importantly, the upregulation of SIRT1 and FOXO1 expression not only increased the level of autophagy but also improved the expression of chondrocyte extracellular matrix proteins. Furthermore, upregulated SIRT1 and FOXO1 expression alleviated the destruction of the articular cartilage in an OA rat model. Our results suggest that SIRT1/FOXO1 signaling can alleviate oleic acid- and linoleic acid-induced cartilage degradation both in vitro and in vivo and that the SIRT1/FOXO1 pathway may serve as an effective treatment target for inhibiting OA progression.

Evening primrose oil enriched with gamma linolenic acid and D/L-alpha tocopherol acetate attenuated carbon tetrachloride-induced hepatic injury model in male rats via TNF-α, IL-1ß, and IL-6 pathway.

The modulatory role of primrose oil (PO) supplementation enriched with γ-linolenic acid and D/L-alpha tocopherol acetate against a carbon tetrachloride (CCl4)-induced liver damage model was assessed in this study. Twenty male Albino rats were divided into four groups. The control group received corn oil orally. The PO group received 10 mg/kg P O orally. The CCl4 group received 2 mL/kg CCl4 orally and PO/CCl4 group; received PO and 2 mL/kg CCl4 orally. The relative liver weight was recorded. Serum liver enzymes, hepatic malondialdehyde (MDA), hepatic reduced glutathione (GSH) and the expression of hepatic tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1ß), and interleukin 6 (IL-6) were assessed. The binding affinities of γ-linolenic acid and D/L-alpha tocopherol constituents with IL-1ß, IL-6 and TNF-α were investigated using molecular docking simulations. Histopathological and electron microscopic examinations of the liver were performed. The results indicated that CCl4 elevated serum liver enzyme and hepatic MDA levels, whereas GSH levels were diminished. The upregulation of IL-1ß, IL-6, and TNF-α gene expressions were induced by CCl4 treatment. The PO/CCl4-treated group showed amelioration of hepatic injury biomarkers and oxidative stress. Restoration of histopathological and ultrastructural alterations while downregulations the gene expressions of TNF-α, IL1-ß and IL-6 were observed. In conclusion, evening primrose oil enriched with γ-linolenic acid and D/L-alpha tocopherol acetate elicited a potential amelioration of CCl4-induced hepatic toxicity.

Camel milk peptides alleviate hyperglycemia by regulating gut microbiota and metabolites in type 2 diabetic mice.

This study aimed to investigate the hypoglycemic effect of Camel milk peptides (CMPs) on Type 2 diabetes mellitus (T2DM) mice and reveal its related mechanism from the aspect of gut microbiota and metabolites. The administering CMPs significantly alleviated the weight loss, polydipsia and polyphagia, reduced fasting blood glucose (FBG), improved insulin resistance and sensitivity, and restored the level of serum hormones, lipopolysaccharide (LPS), lipid metabolic and tissue damage. Furthermore, CMPs intervention remarkably reversed gut microbiota dysbiosis in T2DM mice by reducing the relative abundance of Proteobacteria, Allobaculum, Clostridium, Shigella and the Firmicutes/Bacteroidetes ratio, while increasing the relative abundance of Bacteroidetes and Blautia. Metabolomic analysis identified 84 different metabolites between T2DM and CMPs-treated groups, participating in three pathways of Pantothenate and CoA biosynthesis, Phenylalanine metabolism and Linoleic acid metabolism. Ureidopropionic acid, pantothenic acid, hippuric acid, hydrocinnamic acid and linoleic acid were identified as key acidic metabolites closely related to hypoglycemic effect. Correlation analysis indicated that CMPs might have a hypoglycemic effect through their impact on gut microbiota, leading to variations in short-chain fatty acids (SCFAs), acidic metabolites and metabolic pathways. These findings suggest that CMPs could be a beneficial nutritional supplement for intervention T2DM.

Mechanistic understanding of KCNQ1 activating polyunsaturated fatty acid analogs.

The KCNQ1 channel is important for the repolarization phase of the cardiac action potential. Loss of function mutations in KCNQ1 can cause long QT syndrome (LQTS), which can lead to cardiac arrythmia and even sudden cardiac death. We have previously shown that polyunsaturated fatty acids (PUFAs) and PUFA analogs can activate the cardiac KCNQ1 channel, making them potential therapeutics for the treatment of LQTS. PUFAs bind to KCNQ1 at two different binding sites: one at the voltage sensor (Site I) and one at the pore (Site II). PUFA interaction at Site I shifts the voltage dependence of the channel to the left, while interaction at Site II increases maximal conductance. The PUFA analogs, linoleic-glycine and linoleic-tyrosine, are more effective than linoleic acid at Site I, but less effective at Site II. Using both simulations and experiments, we find that the larger head groups of linoleic-glycine and linoleic-tyrosine interact with more residues than the smaller linoleic acid at Site I. We propose that this will stabilize the negatively charged PUFA head group in a position to better interact electrostatically with the positively charges in the voltage sensor. In contrast, the larger head groups of linoleic-glycine and linoleic-tyrosine compared with linoleic acid prevent a close fit of these PUFA analogs in Site II, which is more confined. In addition, we identify several KCNQ1 residues as critical PUFA-analog binding residues, thereby providing molecular models of specific interactions between PUFA analogs and KCNQ1. These interactions will aid in future drug development based on PUFA-KCNQ1 channel interactions.

Phenotype microarray analysis reveals the biotransformation of Fusarium oxysporum f.sp. lycopersici influenced by Bacillus subtilis PBE-8 metabolites.

Herein, Bacillus subtilis PBE-8's biocontrol efficacy was evaluated through physiological and metabolic approaches against Fusarium oxysporum f.sp. lycopersici (FOL). The study elaborates on PBE-8's cell-free filtrate (CFF) antifungal activity through mycelial growth inhibition, metabolite profiling, and substrates utilization patterns. Additionally, under different CFF concentrations, reduction in spore count (94%-55%), biomass (50%), and cytoplasmic bulbous protrusions in mycelia were also observed. Furthermore, the effect of bacterial CFF on FOL metabolism was confirmed through GC-MS. CFF suppresses the concentration of aliphatic amino acids like L-valine, L-leucine, L-Isoleucine, glycine, and fatty acids such as linoleic acid and α- linolenic acid during the co-culturing conditions, which are essential for pathogenicity and resistance against host's systemic acquired resistance. The phenotype microarray assay revealed that CFF-treated FOL shows phenotype loss in 507 (56.58%) out of 896 substrates. Among 507, twenty-seven substrates showed significant phenotype loss, among which four substrates such as L-glutamic acid, L-glutamine, ammonia, and L-arginine are common in different crucial metabolic pathways of FOL, like alanine, aspartate, and glutamate metabolism, arginine and proline, carbon metabolism, arginine biosynthesis, nitrogen metabolism, amino-acyl tRNA synthesis, and biosynthesis of amino acids. The results suggest that PBE-8 CFF has certain antifungal metabolites that hinder the fungal metabolic pathways.

Effects of polystyrene microplastics acute exposure in the liver of swordtail fish (Xiphophorus helleri) revealed by LC-MS metabolomics.

As global pollution, microplastics pollution has aroused growing concerns. In our experiment, the effect of microplastics acute exposure on the liver of swordtail fish was investigated by using LC-MS metabolomics. Fishes treated with high concentration polystyrene microspheres (1 µm) for 72 h were divided into three concentration groups: (A) no microplastics, (B): 1 × 106 microspheres L-1, (C): 1 × 107 microspheres L-1. Metabolomic analysis indicated that exposure to microplastics caused alterations of metabolic profiles in swordtail fish, including 37 differential metabolites were identified in B vs. A, screened out ten significant metabolites, which involved 14 metabolic pathways. One hundred three differential metabolites were identified in C vs. A, screened out 16 significant metabolites, which involved 30 metabolic pathways. Six significant metabolites were overlapping in group B vs. A and C vs. A; they are 3-hydroxyanthranilic acid, l-histidine, citrulline, linoleic acid, pantothenate, and xanthine. In addition, four metabolic pathways are overlapping in group B vs. A and C vs. A; they are beta-alanine metabolism, biosynthesis of amino acids, linoleic acid metabolism, and aminoacyl-tRNA biosynthesis. These differential metabolites were involved in oxidative stress, immune function, energy metabolism, sugar metabolism, lipid metabolism, molecule transport, and weakened feed utilization, growth performance, nutrient metabolism, and animal growth. Furthermore, we found that the number of interfered amino acids and microplastics showed a dose-effect. In summary, great attention should be paid to the potential impact of microplastics on aquatic organisms.

Equilibration solution composition and extended exposure to equilibration phase affect embryo development and lipid profile of mouse oocytes.

RESEARCH QUESTION: Can exposure time to equilibration solutions during oocyte vitrification affect the lipid profile of oocytes and embryonic development? Could vitrification media supplemented with oleic, linoleic acids and L-carnitine effectively minimize damage induced by vitrification on embryo development and oocyte membrane lipid profile? DESIGN: Experimental study including 936 oocytes from C57BL/6J mice, randomly divided into fresh IVF (control) and equilibration solution groups. Oocytes were exposed to equilibration solution from Irvine Scientific, Tvitri-4 or Tvitri-4 supplemented with L-carnitine and fatty acids for 7 or 10 min, vitrified-warmed, and submitted to IVF. The lipid profile of oocytes immediately after equilibration solution exposure was also asessed using the same equilibration times and solution compositions. RESULTS: Longer equilibration time resulted in lower oocyte survival and blastocyst rates, and reduced relative abundance of structural lipids, i.e. phosphatidylcholines and sphingomyelins, varying according to equilibration solution composition. It also induced membrane disruptions resembling bubbles in the oocyte surface predominantly in equilibration solution from Irvine Scientific, rarely in Tvitri-4 and absent in Tvitri-4 supplemented with L-carnitine and fatty acids. To reveal the metabolic pathways associated with the equilibration phase of vitrification, lipid pathway analysis was conducted; both P-values and pathway impact values showed that the linoleic acid metabolism (P = 0.00223; impact =1) and alpha-Linolenic acid metabolism (P = 0.00084; impact = 0.33) were the most pathway perturbed, followed by glycerophospholipid metabolism (P = 0.0167; impact = 0.25) CONCLUSION: A longer equilibration phase pre-vitrification can influence embryo development and induce changes in oocyte lipid composition related to membrane integrity. The results suggest internalization of oleic and linoleic acids added to equilibration solution by the oocyte, which, to some extent, contributed to membrane phospholipids preservation, regardless of the equilibration times assessed.

Allosteric Regulation of the Soluble Epoxide Hydrolase by Nitro Fatty Acids: a Combined Experimental and Computational Approach.

The human soluble epoxide hydrolase (hsEH) is a key regulator of epoxy fatty acid (EpFA) metabolism. Inhibition of sEH can maintain endogenous levels of beneficial EpFAs and reduce the levels of their corresponding diol products, thus ameliorating a variety of pathological conditions including cardiovascular, central nervous system and metabolic diseases. The quest for orthosteric drugs that bind directly to the catalytic crevice of hsEH has been prolonged and sustained over the past decades, but the disappointing outcome of clinical trials to date warrants alternative pharmacological approaches. Previously, we have shown that hsEH can be allosterically inhibited by the endogenous electrophilic lipid 15-deoxy-Δ12,14-Prostaglandin-J2, via covalent adduction to two cysteines, C423 and C522. In this study, we explore the properties and behaviour of three electrophilic lipids belonging to the class of the nitro fatty acids, namely 9- and 10-nitrooleate and 10-nitrolinoleate. Biochemical and biophysical investigations revealed that, in addition to C423 and C522, nitro fatty acids can covalently bind to additional nucleophilic residues in hsEH C-terminal domain (CTD), two of which predicted in this study to be latent allosteric sites. Systematic mapping of the protein mutational space and evaluation of possible propagation pathways delineated selected residues, both in the allosteric patches and in other regions of the enzyme, envisaged to play a role in allosteric signalling. The responses elicited by the ligands on the covalent adduction sites supports future fragment-based design studies of new allosteric effectors for hsEH with increased efficacy and selectivity.

Effect of different dietary fats on inflammation and glucose intolerance in high fructose and high fat fed experimental animals.

OBJECTIVES: Diet is the major modifiable risk factor for the onset of insulin resistance and its progression into diabetes. In the present study the effect of various dietary fats on inflammatory homeostasis and glucose tolerance is investigated in high fat and high fructose fed mice model. METHODS: C57/BL6J mice were divided into four groups and fed a casein-based diet containing high fructose (45%) and high fat (24%) (clarified butter oil [CBO]; safflower oil [SFFO] and lard oil [LO]) for 120 days; oral glucose tolerance (OGTT), plasma lipid profile and plasma & adipose tissue cytokines levels were compared with the control diet (10% groundnut oil and 59.5% starch) fed animals. RESULTS: The total cholesterol and triglycerides were higher in CBO and LO fed animals with glucose intolerance and increased body weights; liver and white adipose tissue weights were higher in CBO and LO fed animals respectively. CBO feeding increased the plasma (IFN-γ) and adipose tissue cytokines (IFN-γ, IL-10, IL-6 & TNF-α). LO feeding increased plasma IFN-γ, TNF-α and IL-1ß and adipose tissue IL-6. SFFO feeding decreased body weight and tissue cytokines and increased plasma IFN-γ levels without causing impairment in the glucose tolerance. CONCLUSIONS: Consumption of a high fructose and high fat diet which mimic the present-day dietary pattern resulted in altered inflammatory homeostasis and impairment in glucose tolerance in 24% CBO and LO fed animals. The deleterious effects of high fructose feeding were reversed in SFFO fed mice possibly due to the presence of oleic and linoleic acids.

Palmitic acid-induced defects in cell cycle progression and cytokinesis in Neuro-2a cells.

Obesity is associated with elevated levels of free fatty acids (FFAs). Excessive saturated fatty acids (SFAs) exhibit significant deleterious cytotoxic effects in many types of cells. However, the effects of palmitic acid (PA), the most common circulating SFA, on cell cycle progression in neuronal cells have not been well-examined. The aim of this study was to examine whether PA affects the proliferation and cell cycle progression in mouse neuroblastoma Neuro-2a (N2a) cells. Our studies found that 200 µM PA significantly decreased DNA synthesis and mitotic index in N2a cells as early as 4 h following treatment. 24 h treatment with 200 µM PA significantly decreased the percentage of diploid (2 N) cells while dramatically increasing the percentage of tetraploid (4 N) cells as compared to the BSA control. Moreover, our studies found that 24 h treatment with 200 µM PA increased the percentage of binucleate cells as compared to the BSA control. Our studies also found that unsaturated fatty acids (UFAs), including linoleic acid, oleic acid, α-linolenic acid, and docosahexaenoic acid, were able to abolish PA-induced decrease of 2 N cells, increase of 4 N cells, and accumulation of binucleate cells. Taken together, these results suggest that PA may affect multiple aspects of the cell cycle progression in N2a cells, including decreased DNA synthesis, G2/M arrest, and cytokinetic failure, which could be abolished by UFAs.Abbreviations: 4-PBA, 4-Phenylbutyric Acid; ALA, α-linolenic acid; BrdU, 5-bromo-2'-deoxyuridine; DAPI, 4',6-diamidino-2-phenylindole; ER, endoplasmic reticulum; FFA, free fatty acids; FITC, fluorescein isothiocyanate; LA, linoleic acid; MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; N2a, Neuro-2a; NAC, N-acetyl cysteine; OA, oleic acid; PA, palmitic acid; pHH3, Phosphorylation of histone H3; PI, propidium iodide; SFA, saturated fatty acids; PUFA, polyunsaturated fatty acids; TUNEL, terminal deoxynucleotidyl transferase dUTP nick end labeling; UFA, unsaturated fatty acids.

Synthesis and molecular targets of N-13-hydroxy-octadienoyl-ethanolamine, a novel endogenous bioactive 15-lipoxygenase-derived metabolite of N-linoleoyl-ethanolamine found in the skin and saliva.

N-Arachidonoyl-ethanolamine (AEA) is an endocannabinoid (eCB) and endogenous lipid mimicking many of the effects of Δ9-tetrahydrocannabinol, notably on brain functions, appetite, pain and inflammation. The eCBs and eCB-like compounds contain fatty acids, the main classes being the monoacylglycerols and the N-acyl-ethanolamines (NAEs). Thus, each long chain fatty acid likely exists under the form of a monoacylglycerol and NAE, as it is the case for arachidonic acid (AA) and linoleic acid (LA). Following their biosynthesis, AA and AEA can be further metabolized into additional eicosanoids, notably by the 15-lipoxygenase pathway. Thus, we postulated that NAEs possessing a 1Z,4Z-pentadiene motif, near their omega end, would be transformed into their 15-lipoxygenase metabolites. As a proof of concept, we investigated N-linoleoyl-ethanolamine (LAE). We successfully synthesized LEA and LEA-d4 as well as their 15-lipoxygenase-derived derivatives, namely 13-hydroxy-9Z,11E-octadecadienoyl-N-ethanolamine (13-HODE-EA) and 13-HODE-EA-d4, using Novozyme 435 immobilized on acrylic resin and soybean lipoxygenase respectively. We also show that both human 15-lipoxygenase-1 and -2 can biosynthesize 13-HODE-EA. Co-incubation of LEA and LA with either human 15-lipoxygenase led to the biosynthesis of 13-HODE-EA and 13-HODE in a ratio equal to or greater than 3:1, indicating that LEA is preferred to LA by these enzymes. Finally, we show that 13-HODE-EA is found in human saliva and skin and is a weak although selective TRPV1 agonist. The full biological importance of 13-HODE-EA remains to be explored.

In vitro and in vivo effects of P-MAPA immunomodulator on schistosomiasis.

Schistosomiasis is an infectious disease caused by helminth parasites of the genus Schistosoma; it is transmitted in over 78 countries. The main strategy for schistosomiasis control is treatment of infected people with praziquantel (PZQ). As PZQ-resistant strains have emerged, new anti-schistosomal agents have become necessary. We evaluated the in vitro and in vivo effect of P-MAPA, an aggregated polymer of protein magnesium ammonium phospholinoleate-palmitoleate anhydride with immunomodulatory properties; it is produced by Aspergillus oryzae fermentation. In vitro, P-MAPA (5, 50, and 100 µg/mL) damaged the Schistosoma mansoni tegument, causing thorn losses and tuber destruction in male worms and peeling and erosion in females after 24-h incubation. In vivo, P-MAPA (5 and 100 mg/kg, alone and combined with PZQ - 50 mg/kg) reduced the number of eggs by up to 69.20% in the liver and 88.08% in the intestine. Furthermore, granulomas were reduced up to 83.13%, and there was an increase in the number of dead eggs and a reduction of serum aspartate aminotransferase levels. These data suggest that P-MAPA activity can help improve schistosomiasis treatment and patients' quality of life.

Regulation of flowering under short photoperiods based on transcriptomic and metabolomic analysis in Phaseolus vulgaris L.

Common bean (Phaseolus vulgaris L.) is a short-day plant and its flowering time, and consequently, pod yield and quality is influenced by photoperiod. In this study, the photoperiodic-sensitive variety 'Hong jin gou', which flowers 31 days (d) earlier in short-day than in long-day, was used as the experimental material. Samples were collected to determine the growth and photosynthetic parameters in each daylength treatment, and transcriptome and metabolome data were conducted. We identified eight genes related to flowering by further screening for differentially expressed genes. These genes function to regulate the biological clock. The combination of differentially expressed genes and metabolites, together with the known regulation network of flowering time and the day-night expression pattern of related genes allow us to speculate on the regulation of flowering time in the common bean and conclude that TIMING OF CAB EXPRESSION1 (TOC1) plays a pivotal role in the network and its upregulation or downregulation causes corresponding changes in the expression of downstream genes. The regulatory network is also influenced by gibberellic acid (GA) and jasmonic acid (JA). These regulatory pathways jointly comprise the flowering regulatory network in common bean.

Friedreich Ataxia: current state-of-the-art, and future prospects for mitochondrial-focused therapies.

Friedreich's Ataxia is an autosomal recessive genetic disease causing the defective gene product, frataxin. A body of literature has been focused on the attempts to counteract frataxin deficiency and the consequent iron imbalance, in order to mitigate the disease-associated pro-oxidant state and clinical course. The present mini review is aimed at evaluating the basic and clinical reports on the roles and the use of a set of iron chelators, antioxidants and some cofactors involved in the key mitochondrial functions. Extensive literature has focused on the protective roles of iron chelators, coenzyme Q10 and analogs, and vitamin E, altogether with varying outcomes in clinical studies. Other studies have suggested mitoprotective roles for other mitochondrial cofactors, involved in Krebs cycle, such as alpha-lipoic acid and carnitine, involved in acyl transport across the mitochondrial membrane. A body of evidence points to the strong antioxidant properties of these cofactors, and to their potential contribution in mitoprotective strategies in Friedreich's Ataxia clinical evolution. Thus, we suggest the rationale for planning combination strategies based on the 3 mitochondrial cofactors and of some antioxidants and iron binders as mitoprotective cocktails in Friedreich Ataxia patients, calling attention to clinical practitioners of the importance to implement clinical trials.

The anti-cancer drug ABTL0812 induces ER stress-mediated cytotoxic autophagy by increasing dihydroceramide levels in cancer cells.

ABTL0812 is a first-in-class small molecule with anti-cancer activity, which is currently in clinical evaluation in a phase 2 trial in patients with advanced endometrial and squamous non-small cell lung carcinoma (NCT03366480). Previously, we showed that ABTL0812 induces TRIB3 pseudokinase expression, resulting in the inhibition of the AKT-MTORC1 axis and macroautophagy/autophagy-mediated cancer cell death. However, the precise molecular determinants involved in the cytotoxic autophagy caused by ABTL0812 remained unclear. Using a wide range of biochemical and lipidomic analyses, we demonstrated that ABTL0812 increases cellular long-chain dihydroceramides by impairing DEGS1 (delta 4-desaturase, sphingolipid 1) activity, which resulted in sustained ER stress and activated unfolded protein response (UPR) via ATF4-DDIT3-TRIB3 that ultimately promotes cytotoxic autophagy in cancer cells. Accordingly, pharmacological manipulation to increase cellular dihydroceramides or incubation with exogenous dihydroceramides resulted in ER stress, UPR and autophagy-mediated cancer cell death. Importantly, we have optimized a method to quantify mRNAs in blood samples from patients enrolled in the ongoing clinical trial, who showed significant increased DDIT3 and TRIB3 mRNAs. This is the first time that UPR markers are reported to change in human blood in response to any drug treatment, supporting their use as pharmacodynamic biomarkers for compounds that activate ER stress in humans. Finally, we found that MTORC1 inhibition and dihydroceramide accumulation synergized to induce autophagy and cytotoxicity, phenocopying the effect of ABTL0812. Given the fact that ABTL0812 is under clinical development, our findings support the hypothesis that manipulation of dihydroceramide levels might represents a new therapeutic strategy to target cancer.Abbreviations: 4-PBA: 4-phenylbutyrate; AKT: AKT serine/threonine kinase; ATG: autophagy related; ATF4: activating transcription factor 4; Cer: ceramide; DDIT3: DNA damage inducible transcript 3; DEGS1: delta 4-desaturase, sphingolipid 1; dhCer: dihydroceramide; EIF2A: eukaryotic translation initiation factor 2 alpha; EIF2AK3: eukaryotic translation initiation factor 2 alpha kinase 3; ER: endoplasmic reticulum; HSPA5: heat shock protein family A (Hsp70) member 5; MAP1LC3B: microtubule associated protein 1 light chain 3 beta; MEF: mouse embryonic fibroblast; MTORC1: mechanistic target of rapamycin kinase complex 1; NSCLC: non-small cell lung cancer; THC: Δ9-tetrahydrocannabinol; TRIB3: tribbles pseudokinase 3; XBP1: X-box binding protein 1; UPR: unfolded protein response.

The P-MAPA Immunomodulator Partially Prevents Apoptosis Induced by Zika Virus Infection in THP-1 Cells.

BACKGROUND: Zika virus is an emerging arbovirus of global importance. ZIKV infection is associated with a range of neurological complications such as the Congenital Zika Syndrome and Guillain Barré Syndrome. Despite the magnitude of recent outbreaks, there is no specific therapy to prevent or to alleviate disease pathology. OBJECTIVE: To investigate the role of P-MAPA immunomodulator in Zika-infected THP-1 cells. METHODS: THP-1 cells were subjected to Zika virus infection (Multiplicity of Infection = 0.5) followed by treatment with P-MAPA for until 96 hours post-infection. After that, the cell death was analyzed by annexin+/ PI+ and caspase 3/ 7+ staining by flow cytometry. In addition, virus replication and cell proliferation were accessed by RT-qPCR and Ki67 staining, respectively. RESULTS: We demonstrate that P-MAPA in vitro treatment significantly reduces Zika virus-induced cell death and caspase-3/7 activation on THP-1 infected cells, albeit it has no role in virus replication and cell proliferation. CONCLUSION: Our study reveals that P-MAPA seems to be a satisfactory alternative to inhibit the effects of Zika virus infection in mammalian cells.

N-Benzyl-linoleamide, a Constituent of Lepidium meyenii (Maca), Is an Orally Bioavailable Soluble Epoxide Hydrolase Inhibitor That Alleviates Inflammatory Pain.

Lepidium meyenii (maca), a plant indigenous to the Peruvian Andes, recently has been utilized globally for claimed health or recreational benefits. The search for natural products that inhibit soluble epoxide hydrolase (sEH), with therapeutically relevant potencies and concentrations, led to the present study on bioactive amide secondary metabolites found in L. meyenii, the macamides. Based on known and suspected macamides, 19 possible macamides were synthesized and characterized. The majority of these amides displayed excellent inhibitory potency (IC50 ≈ 20-300 nM) toward the recombinant mouse, rat, and human sEH. Quantitative analysis of commercial maca products revealed that certain products contain known macamides (1-5, 8-12) at therapeutically relevant total concentrations (≥3.29 mg/g of root), while the inhibitory potency of L. meyenii extracts directly correlates with the sum of concentration/IC50 ratios of macamides present. Considering both its in vitro efficacy and high abundance in commercial products, N-benzyl-linoleamide (4) was identified as a particularly relevant macamide that can be utilized for in vivo studies. Following oral administration in the rat, compound 4 not only displayed acceptable pharmacokinetic characteristics but effectively reduced lipopolysaccharide-induced inflammatory pain. Inhibition of sEH by macamides provides a plausible biological mechanism of action to account for several beneficial effects previously observed with L. meyenii treatments.

P-MAPA, a Fungi-Derived Immunomodulatory Compound, Induces a Proinflammatory Response in a Human Whole Blood Model.

P-MAPA is a complex compound, derived from Aspergillus oryzae cultures, that has shown immunomodulatory properties in infection and cancer animal models. Despite promising results in these models, the mechanisms of cellular activation by P-MAPA, suggested to be Toll-like receptor- (TLR-) dependent, and its effect on human immune cells, remain unclear. Using an ex vivo model of human whole blood, the effects of P-MAPA on complement system activation, production of cytokines, and the expression of complement receptors (CD11b, C5aR, and C3aR), TLR2, TLR4, and the coreceptor CD14 were analyzed in neutrophils and monocytes. P-MAPA induced complement activation in human blood, detected by increased levels of C3a, C5a, and SC5b-9 in plasma. As a consequence, CD11b expression increased and C5aR decreased upon activation, while C3aR expression remained unchanged in leukocytes. TLR2 and TLR4 expressions were not modulated by P-MAPA treatment on neutrophils, but TLR4 expression was reduced in monocytes, while CD14 expression increased in both cell types. P-MAPA also induced the production of TNF-α, IL-8, and IL-12 and oxidative burst, measured by peroxynitrite levels, in human leukocytes. Complement inhibition with compstatin showed that P-MAPA-induced complement activation drives modulation of C5aR, but not of CD11b, suggesting that P-MAPA acts through both complement-dependent and complement-independent mechanisms. Compstatin also significantly reduced the peroxynitrite generation. Altogether, our results show that P-MAPA induced proinflammatory response in human leukocytes, which is partially mediated by complement activation. Our data contribute to elucidate the complement-dependent and complement-independent mechanisms of P-MAPA, which ultimately result in immune cell activation and in its immunomodulatory properties in infection and cancer animal models.

The dietary peroxidized lipid, 13-HPODE, promotes intestinal inflammation by mediating granzyme B secretion from natural killer cells.

It is well known that consumption of a high-fat diet (HFD) promotes intestinal inflammation despite little being known about causative factors. Recent evidence implicates dietary peroxidized lipids (POLs), which are typically formed from the oxidation of polyunsaturated fatty acid double bonds, as potential contributors due to their enrichment in HFDs, ability to be formed during gastrointestinal transit, and immunogenic and cytotoxic properties. 13-HPODE, the most common dietary POL, demonstrates pro-inflammatory activity in a variety of immune cells, especially Natural Killer (NK) cells whose role in mediating intestinal inflammation remains unclear. Therefore, we set out to investigate how 13-HPODE and other POLs modulate NK-cell activity in the context of intestinal inflammation. We not only found that NK cells fully decompose exogenous 13-HPODE, but that direct treatment stimulates TNF-α and MCP1 expression as well as Granzyme B (GZMB) secretion in a dose-dependent manner. Similar results were observed upon incubation of NK cells with oxidized, but not-unoxidized, low-density lipoproteins. Secretory products from 13-HPODE-treated NK cells were able to induce Caco2 intestinal cell inflammation in the same way as exogenous GZMB with greater sensitivity in undifferentiated compared to differentiated cells. Results were recapitulated in 13-HPODE-fed mice, demonstrating both spatial and temporal patterns of elevated GZMB expression that favored acute treatments in the distal intestinal epithelium. Collectively, our results suggest that that HFD-derived POLs, like 13-HPODE, potentially contribute to intestinal inflammation by stimulating the secretion of pro-inflammatory granzymes by resident NK cells, ultimately revealing a more direct role for diet in modulating gut homeostasis and the immune environment.

The antitumour drug ABTL0812 impairs neuroblastoma growth through endoplasmic reticulum stress-mediated autophagy and apoptosis.

Neuroblastoma is the leading cause of cancer death in children aged 1 to 4 years. Particularly, five-year overall survival for high-risk neuroblastoma is below 50% with no curative options when refractory or relapsed. Most of current therapies target cell division and proliferation, thereby inducing DNA damage and programmed cell death. However, aggressive tumours often present alterations of these processes and are resistant to therapy. Therefore, exploring alternative pathways to induce tumour cell death will provide new therapeutic opportunities for these patients. In this study we aimed at testing the therapeutic potential of ABTL0812, a novel anticancer drug that induces cytotoxic autophagy to eliminate cancer cells, which is currently in phase II clinical trials of adult tumours. Here, we show that ABTL0812 impaired the viability of clinical representative neuroblastoma cell lines regardless of genetic alterations associated to bad prognosis and resistance to therapy. Oral administration of ABTL0812 to mice bearing neuroblastoma xenografts impaired tumour growth. Furthermore, our findings revealed that, in neuroblastoma, ABTL0812 induced cancer cell death via induction of endoplasmic reticulum stress, activation of the unfolded protein response, autophagy and apoptosis. Remarkably, ABTL0812 potentiated the antitumour activity of chemotherapies and differentiating agents such as irinotecan and 13-cis-retinoic acid. In conclusion, ABTL0812 distinctive mechanism of action makes it standout to be used alone or in combination in high-risk neuroblastoma patients.