Pro-resolving and pro-inflammatory fatty acid-derived mediators in sputum of stable state bronchiectasis patients.

BACKGROUND: Bronchiectasis is characterized by neutrophilic inflammation and frequent exacerbations often associated with infections. Lipid mediators play critical roles in the inflammatory response, and the balance between anti-inflammatory and pro-inflammatory mediators could drive to chronic inflammation. The aim of this study was to evaluate the metabolites of docosahexaenoic acid and arachidonic acid in sputum of adults with bronchiectasis defining their associations with clinical data, bacterial load and neutrophil elastase. METHODS: An observational, cross-sectional study was conducted at the bronchiectasis program of the Policlinico Hospital in Milan, Italy, where patients were enrolled. Active neutrophil elastase was measured by enzyme-linked immunosorbent assay, pro-resolving and pro-inflammatory fatty acid-derived mediators were evaluated by mass spectrometry and respiratory pathogens were assessed by real-time PCR. Analysis were performed on sputum collected during stable state and clinical data were also collected. RESULTS: Levels of pro-inflammatory mediators derived from arachidonic acid metabolism showed association with neutrophil elastase, were proportional to Pseudomonas aeruginosa identifications and were linked with radiological gravity index, while the concentrations of pro-resolution mediators derived from docosahexaenoic acid were associated with a better health status, highlighted by the inverse correlation with radiological gravity index, bacterial infections and sputum volume production. CONCLUSION: Pro-inflammatory mediators derived from FA metabolisms are associated with severity of bronchiectasis while DHA-derived metabolites are inversely associated with severity of the disease, which may be used for personized treatment of bronchiectasis.

Increased dietary levels of α-linoleic acid inhibit mammary tumor growth and metastasis.

OBJECTIVE: The aim of this study was to determine whether α-linolenic acid (ALA ω-3 fatty acid) enriched diet affects growth parameters when applied to a syngeneic model of mammary carcinoma. MATERIALS AND METHODS: BALB/c mice were divided and fed with: 1) a chia oil diet, rich in ALA or 2) a corn oil diet, rich in linoleic acid (LA ω-6 fatty acid). Mice were subcutaneously inoculated with a tumor cell line LM3, derived from a murine mammary adenocarcinoma. RESULTS: After 35 days, tumor incidence, weight, volume and metastasis number were lower in the ALA-fed mice, while tumor latency time was higher, and the release of pro-tumor metabolites derived from ω-6 fatty acids decreased in the tumor. Compared to the control group, a lower number of mitosis, a higher number of apoptotic bodies and higher T-lymphocyte infiltration were consistently observed in the ALA group. An ALA-rich diet decreased the estrogen receptor (ER) α expression, a recognized breast cancer promotor while showing an opposite effect on ERß in tumor lysates. CONCLUSION: These data support the anticancer effect of an ALA-enriched diet, which might be used as a dietary strategy in breast cancer prevention.

The use of circulating cathodic antigen rapid test and serology for diagnosis of active Schistosoma mansoni infection in migrants in Italy, a non-endemic country: a cross sectional study.

Diagnosis of schistosomiasis in migrants coming from endemic areas can be difficult, especially in asymptomatic subjects. Light-intensity disease, in fact, may be missed due to the low sensitivity of the stool microscopy and serologic testing cannot distinguish between a resolved infection and an active infection in patients who have been infected and treated in the past, because specific antibodies can persist despite cure. We describe a cross-sectional study conducted on 82 migrants tested for Schistosoma mansoni on single blood (anti-schistosome antibodies, total IgE) and urine [point-of-care (POC) circulating-cathodic-antigen (CCA) test] samples. A positive POC-CCA test (active infection) resulted in two untreated patients with a positive serology while all patients (n = 66) with a past infection showed a negative POC-CCA test. POC-CCA urine test in combination with serology may be helpful in rapidly differentiate active from past S. mansoni infection in migrants coming from endemic areas.

Transcellular biosynthesis of eicosanoid lipid mediators.

The synthesis of oxygenated eicosanoids is the result of the coordinated action of several enzymatic activities, from phospholipase A2 that releases the polyunsaturated fatty acids from membrane phospholipids, to primary oxidative enzymes, such as cyclooxygenases and lipoxygenases, to isomerases, synthases and hydrolases that carry out the final synthesis of the biologically active metabolites. Cells possessing the entire enzymatic machinery have been studied as sources of bioactive eicosanoids, but early on evidence proved that biosynthetic intermediates, albeit unstable, could move from one cell type to another. The biosynthesis of bioactive compounds could therefore be the result of a coordinated effort by multiple cell types that has been named transcellular biosynthesis of the eicosanoids. In several cases cells not capable of carrying out the complete biosynthetic process, due to the lack of key enzymes, have been shown to efficiently contribute to the final production of prostaglandins, leukotrienes and lipoxins. We will review in vitro studies, complex functional models, and in vivo evidences of the transcellular biosynthesis of eicosanoids and the biological relevance of the metabolites resulting from this unique biosynthetic pathway. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance".

In vitro pharmacological evaluation of multitarget agents for thromboxane prostanoid receptor antagonism and COX-2 inhibition.

PURPOSE: Patients with high cardiovascular risk due to ageing and/or comorbidity (diabetes, atherosclerosis) that require effective management of chronic pain may take advantage from new non-steroidal anti-inflammatory drugs (NSAIDs) that at clinical dosages may integrate the anti-inflammatory activity and reduced gastrointestinal side effects of selective cyclooxygenase-2 (COX-2) inhibitor (coxib) with a cardioprotective component involving antagonism of thromboxane A2 prostanoid (TP) receptor. METHODS: New compounds were obtained modulating the structure of the most potent coxib, lumiracoxib, to obtain novel multitarget NSAIDs endowed with balanced coxib and TP receptor antagonist properties. Antagonist activity at TP receptor (pA2) was evaluated for all compounds in human platelets and in an heterologous expression system by measuring prevention of aggregation and Gq-dependent production of intracellular inositol phosphate induced by the stable thromboxane A2 (TXA2) agonist U46619. COX-1 and COX-2 inhibitory activities were assessed in human washed platelets and lympho-monocytes suspension, respectively. COX selectivity was determined from dose-response curves by calculating a ratio (COX-2/COX-1) of IC50 values. RESULTS: The tetrazole derivative 18 and the trifluoromethan sulfonamido-isoster 20 were the more active antagonists at TP receptor, preventing human platelet aggregation and intracellular signalling, with pA2 values statistically higher from that of lumiracoxib. Comparative data regarding COX-2/COX-1 selectivity showed that while compounds 18 and 7 were rather potent and selective COX-2 inhibitor, compound 20 was somehow less potent and selective for COX-2. CONCLUSION: These results indicate that compounds 18 and 20 are two novel combined TP receptor antagonists and COX-2 inhibitors characterized by a fairly balanced COX-2 inhibitor activity and TP receptor antagonism and that they may represent a first optimization of the original structure to improve their multitarget activity.

CHF6001 II: a novel phosphodiesterase 4 inhibitor, suitable for topical pulmonary administration--in vivo preclinical pharmacology profile defines a potent anti-inflammatory compound with a wide therapeutic window.

CHF6001 [(S)-3,5-dichloro-4-(2-(3-(cyclopropylmethoxy)-4-(difluoromethoxy)phenyl)-2-(3-(cyclopropylmethoxy)-4-(methylsulfonamido)benzoyloxy)ethyl)pyridine 1-oxide] is a novel phosphodiesterase 4 (PDE4) inhibitor designed for use in pulmonary diseases by inhaled administration. Intratracheal administration of CHF6001 to ovalbumin-sensitized Brown-Norway rats suppressed the antigen-induced decline of lung functions (ED50 = 0.1 µmol/kg) and antigen-induced eosinophilia (ED50 = 0.03 µmol/kg) when administered (0.09 µmol/kg) up to 24 hours before antigen challenge, in agreement with CHF6001-sustained lung concentrations up to 72 hours after intratracheal treatment (mean residence time 26 hours). Intranasal, once daily administration of CHF6001 inhibited neutrophil infiltration observed after 11 days of tobacco smoke exposure in mice, both upon prophylactic (0.15-0.45 µmol/kg per day) or interventional (0.045-0.45 µmol/kg per day) treatment. CHF6001 was ineffective in reversing ketamine/xylazine-induced anesthesia (a surrogate of emesis in rat) up to 5 µmol/kg administered intratracheally, a dose 50- to 150-fold higher than anti-inflammatory ED50 observed in rats. When given topically to ferrets, no emesis and nausea were evident up to 10 to 20 µmol/kg, respectively, whereas the PDE4 inhibitor GSK-256066 (6-[3-(dimethylcarbamoyl)phenyl]sulfonyl-4-(3-methoxyanilino)-8-methylquinoline-3-carboxamide) induced nausea at 1 µmol/kg intratracheally. A 14-day inhalation toxicology study in rats showed a no-observed-adverse-effect level dose of 4.4 µmol/kg per day for CHF6001, lower than the 0.015 µmol/kg per day for GSK-256066. CHF6001 was found effective and extremely well tolerated upon topical administration in relevant animal models, and may represent a step forward in PDE4 inhibition for the treatment of asthma and chronic obstructive respiratory disease.

CHF6001 I: a novel highly potent and selective phosphodiesterase 4 inhibitor with robust anti-inflammatory activity and suitable for topical pulmonary administration.

This study examined the pharmacologic characterization of CHF6001 [(S)-3,5-dichloro-4-(2-(3-(cyclopropylmethoxy)-4-(difluoromethoxy)phenyl)-2-(3-(cyclopropylmethoxy)-4-(methylsulfonamido)benzoyloxy)ethyl)pyridine 1-oxide], a novel phosphodiesterase (PDE)4 inhibitor designed for treating pulmonary inflammatory diseases via inhaled administration. CHF6001 was 7- and 923-fold more potent than roflumilast and cilomilast, respectively, in inhibiting PDE4 enzymatic activity (IC50 = 0.026 ± 0.006 nM). CHF6001 inhibited PDE4 isoforms A-D with equal potency, showed an elevated ratio of high-affinity rolipram binding site versus low-affinity rolipram binding site (i.e., >40) and displayed >20,000-fold selectivity versus PDE4 compared with a panel of PDEs. CHF6001 effectively inhibited (subnanomolar IC50 values) the release of tumor necrosis factor-α from human peripheral blood mononuclear cells, human acute monocytic leukemia cell line macrophages (THP-1), and rodent macrophages (RAW264.7 and NR8383). Moreover, CHF6001 potently inhibited the activation of oxidative burst in neutrophils and eosinophils, neutrophil chemotaxis, and the release of interferon-γ from CD4(+) T cells. In all these functional assays, CHF6001 was more potent than previously described PDE4 inhibitors, including roflumilast, UK-500,001 [2-(3,4-difluorophenoxy)-5-fluoro-N-((1S,4S)-4-(2-hydroxy-5-methylbenzamido)cyclohexyl)nicotinamide], and cilomilast, and it was comparable to GSK256066 [6-((3-(dimethylcarbamoyl)phenyl)sulfonyl)-4-((3-methoxyphenyl)amino)-8-methylquinoline-3-carboxamide]. When administered intratracheally to rats as a micronized dry powder, CHF6001 inhibited liposaccharide-induced pulmonary neutrophilia (ED50 = 0.205 µmol/kg) and leukocyte infiltration (ED50 = 0.188 µmol/kg) with an efficacy comparable to a high dose of budesonide (1 µmol/kg i.p.). In sum, CHF6001 has the potential to be an effective topical treatment of conditions associated with pulmonary inflammation, including asthma and chronic obstructive pulmonary disease.

Monitoring inflammation and airway remodeling by fluorescence molecular tomography in a chronic asthma model.

BACKGROUND: Asthma is a multifactorial disease for which a variety of mouse models have been developed. A major drawback of these models is represented by the transient nature of the airway pathology peaking 24-72 h after challenge and resolving in 1-2 weeks. We characterized the temporal evolution of pulmonary inflammation and tissue remodeling in a recently described mouse model of chronic asthma (8 week treatment with 3 allergens: Dust mite, Ragweed, and Aspergillus; DRA). METHODS: We studied the DRA model taking advantage of fluorescence molecular tomography (FMT) imaging using near-infrared probes to non-invasively evaluate lung inflammation and airway remodeling. At 4, 6, 8 or 11 weeks, cathepsin- and metalloproteinase-dependent fluorescence was evaluated in vivo. A subgroup of animals, after 4 weeks of DRA, was treated with Budesonide (100 µg/kg intranasally) daily for 4 weeks. RESULTS: Cathepsin-dependent fluorescence in DRA-sensitized mice resulted significantly increased at 6 and 8 weeks, and was markedly inhibited by budesonide. This fluorescent signal well correlated with ex vivo analysis such as bronchoalveolar lavage eosinophils and pulmonary inflammatory cell infiltration. Metalloproteinase-dependent fluorescence was significantly increased at 8 and 11 weeks, nicely correlated with collagen deposition, as evaluated histologically by Masson's Trichrome staining, and airway epithelium hypertrophy, and was only partly inhibited by budesonide. CONCLUSIONS: FMT proved suitable for longitudinal studies to evaluate asthma progression, showing that cathepsin activity could be used to monitor inflammatory cell infiltration while metalloproteinase activity parallels airway remodeling, allowing the determination of steroid treatment efficacy in a chronic asthma model in mice.

Antiinflammatory and antioxidant effects of H2O2 generated by natural sources in Il1ß-treated human endothelial cells.

Specific reactive oxygen species (ROS) from different sources, might lead to different and even opposite, cellular effects. We studied the production of specific ROS resulting from the exposure of human umbilical veins endothelial cells (HUVEC) to H2O2 derived from the natural antioxidant epigallocathechin gallate (EGCG) or from the exposure to IL-1ß using a fluorogenic probe and flow cytometry, and evaluated by western blot analysis and immunocytochemistry the associated expression of transcription factors sensitive to both inflammatory and oxidative stress, such as NF-κB and Nrf2, and some downstream activated genes such as cyclooxygenase-2 (COX-2) and hemeoxygenase 1 (HO-1). The results obtained showed that exogenously-generated H2O2 induce anti-inflammatory and antioxidant effects in HUVECs counteracting the pro-inflammatory and pro-oxidant effect of IL-1ß related to the production of superoxide anions. The underlying mechanisms resulting from the extracellular production of H2O2, include (1) Nrf2 nuclear translocation and the enhanced expression of antioxidant enzymes such as HO-1, and (2) the previously unreported inhibition of NF-κB and COX-2 expression. Overall, these findings provide evidence that the production of specific reactive oxygen species finely tunes endothelial cell function and might be relevant for the reappraisal of the effects of exogenous antioxidants in the context of cardiovascular diseases.

Autocrine activity of cysteinyl leukotrienes in human vascular endothelial cells: Signaling through the CysLT2 receptor.

We evaluated the autocrine activities of cysteinyl leukotrienes (cysteinyl-LTs) in HUVEC and studied the signaling and the pharmacological profile of the CysLT2 receptor (CysLT2R) expressed by ECs, finally assessing the role of the CysLT2R in permeability alterations in a model of isolated brain. Cysteinyl-LTs and their precursor LTA4 contracted HUVEC and increased permeability to macromolecules, increasing the formation of stress fibers through the phosphorylation of myosin light-chain (MLC) following Rho and PKC activation. Accordingly, in an organ model of cerebral vasculature with an intact intima, neutrophils challenge leaded to significant formation of cysteinyl-LTs and edema. Pretreatment with a selective CysLT2R antagonist prevented cytoskeleton rearrangement and HUVEC contraction, along with edema formation in the brain preparation, while leaving the synthesis of cysteinyl-LTs unaffected. We also demonstrate here that the CysLT1R antagonist zafirlukast, pranlukast, pobilukast and iralukast also possess CysLT2R antagonistic activity, which could help in reconsidering previous data on the role of cysteinyl-LTs in the cardiovascular system. The results obtained are further supporting a potential role for CysLT2R in cardiovascular disease.

Unsaturated fatty acids, omega-3 index and hospitalization in MISC.

The growing interest in Omega-3 fatty acids as diagnostic markers or new therapeutic approaches also for COVID-19 disease, led us to investigate the presence of potential correlations between Omega-3 fatty acids' levels in whole blood and days of hospitalization or admission to the paediatric intensive care unit (PICU) in 51 children with MIS-C diagnosis following SARS-CoV-2 infection. A statistically significant negative correlation was observed between days of hospitalization and docosapentaenoic acid (22:5n-3,DPA), docosahexaenoic acid (DHA) and total Omega-3 FA levels. Dividing the study group into quartiles according to Omega-3-Index (O3I), no statistically significant difference was observed with respect to the PICU admission rate. In contrast, the number of days of hospitalization in Q4 (O3I ≥ 2.51 %) was different from the number observed in groups Q1-3 (O3I < 2.51 %), with subjects showing higher O3I needing shorter hospitalizations than the subjects with lower O3I. According to previous study investigating O3I in adults affected by Sars-cov-2 we explored the levels of this nutrients in children with MIS-C. Our exploratory study shows that high DPA, DHA and O3I levels could be effective in reducing the length of hospitalization.

Harnessing the translational power of bleomycin model: new insights to guide drug discovery for idiopathic pulmonary fibrosis.

Background: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, age-related interstitial lung disease (ILD) with limited therapeutic options. Despite the wide variety of different in vivo models for IPF, these preclinical models have shown limitations that may significantly impair their translational potential. Among the most relevant limitations are the methodologies used to assess the efficacy of anti-fibrotic treatments, that are not the ones used in humans. In this scenario, the goal of the work presented in this paper is to provide translational relevance to the bleomycin (BLM)-induced pulmonary fibrosis mouse model, introducing and validating novel readouts to evaluate the efficacy of treatments for IPF. Methods: The BLM model was optimized by introducing the use of functional assessments such as the Forced Vital Capacity (FVC) and the Diffusion Factor for Carbon Monoxide (DFCO), that are respectively the primary and secondary endpoints in clinical trials for IPF, comparing them to more common readouts such as lung histology, improved by the application of Artificial Intelligence (AI) to detect and quantify fibrotic tissue deposition, and metalloproitenase-7 (MMP-7), a clinical prognostic biomarker. Results: Lung function measurement and DFCO changes well correlated with Ashcroft score, the current gold-standard for the assessment of pulmonary fibrosis in mice. The relevance and robustness of these novel readouts in the BLM model was confirmed by the results obtained testing Nintedanib and Pirfenidone, the only drugs approved for the treatment of IPF patients: in fact, both drugs administered therapeutically, significantly affected the changes in these parameters induced by BLM treatment, with results that closely reflected the efficacy observed in the clinic. Changes in biomarkers such as MMP-7 were also evaluated, and well correlated with the modifications of FVC and DFCO. Conclusion: Novel functional readouts such as FVC and DFCO can be efficiently used to assess pathology progression in the BLM-induced pulmonary fibrosis mouse model as well as compound efficacy, substantially improving its translational and predictivity potential.

Bicalutamide and Trehalose Ameliorate Spinal and Bulbar Muscular Atrophy Pathology in Mice.

Spinal and bulbar muscular atrophy (SBMA) is characterized by motor neuron (MN) degeneration that leads to slowly progressive muscle weakness. It is considered a neuromuscular disease since muscle has a primary role in disease onset and progression. SBMA is caused by a CAG triplet repeat expansion in the androgen receptor (AR) gene. The translated poly-glutamine (polyQ) tract confers a toxic gain of function to the mutant AR altering its folding, causing its aggregation into intracellular inclusions, and impairing the autophagic flux. In an in vitro SBMA neuronal model, we previously showed that the antiandrogen bicalutamide and trehalose, a natural disaccharide stimulating autophagy, block ARpolyQ activation, reduce its nuclear translocation and toxicity and facilitate the autophagic degradation of cytoplasmic AR aggregates. Here, in a knock-in SBMA mouse model (KI AR113Q), we show that bicalutamide and trehalose ameliorated SBMA pathology. Bicalutamide reversed the formation of the AR insoluble forms in KI AR113Q muscle, preventing autophagic flux blockage. We demonstrated that apoptosis is activated in KI AR113Q muscle, and that both compounds prevented its activation. We detected a decrease of mtDNA and an increase of OXPHOS enzymes, already at early symptomatic stages; these alterations were reverted by trehalose. Overall, bicalutamide and/or trehalose led to a partial recovery of muscle morphology and function, and improved SBMA mouse motor behavior, inducing an extension of their survival. Thus, bicalutamide and trehalose, by counteracting ARpolyQ toxicity in skeletal muscle, are valuable candidates for future clinical trials in SBMA patients.

Synthesis of cysteinyl leukotrienes in human endothelial cells: subcellular localization and autocrine signaling through the CysLT2 receptor.

The purpose of this study was to characterize enzyme, receptor, and signaling involved in the synthesis and the activity of cysteinyl leukotrienes (cys-LTs) in human umbilical vein endothelial cells (HUVECs). We used primary cultures of HUVECs and evaluated the formation of cys-LTs by RP-HPLC. Suicide inactivation and subcellular localization of the enzyme responsible for the conversion of leukotriene (LT) A(4) into LTC(4) were studied by repeated incubations with LTA(4) and immunogold electron microscopy. The CysLT(2) receptor in HUVECs was characterized by equilibrium binding studies, Western blot analysis, and immunohistochemistry. Concentration-response curves in HUVECs and in transfected COS-7 cells were used to characterize a novel specific CysLT(2) receptor antagonist (pA(2) of 8.33 and 6.79 against CysLT(2) and CysLT(1) receptors, respectively). The results obtained provide evidence that the mGST-II synthesizing LTC(4) in HUVECs is pharmacologically distinguishable from the LTC(4)-synthase (IC(50) of MK886 <5 µM for LTC(4)-synthase and >30 µM for mGST-II), is not suicide-inactivated and is strategically located on endothelial transport vesicles. The CysLT(2) receptor is responsible for the increase in intracellular Ca(2+) following exposure of HUVECs to cys-LTs and is coupled to a pertussis toxin-insensitive G(q) protein. The synthesis of cys-LTs from LTA(4) by endothelial cells is directly associated with the activation of the CysLT(2) receptor (EC(50) 0.64 µM) in a typical autocrine fashion.

Bronchodilators modulate inflammation in chronic obstructive pulmonary disease subjects.

Chronic obstructive pulmonary disease (COPD) is characterized by neutrophilic airway inflammation and oxidative stress. Leukotriene B4 (LTB4), a potent proinflammatory mediator, is synthesized by 5-lipoxygenase (5-LO), which is activated by the presence of lipid hydroperoxides resulting from oxidative stress on biological membranes. We proposed to evaluate the effect of a four week treatment with two different bronchodilators of common practice in COPD treatment, on the production of reactive oxygen species (ROS), in particular superoxide anions, and of LTB4 by peripheral blood neutrophils obtained from COPD subjects. 24 subjects among the COPD outpatients were enrolled, and randomized to receive either formoterol (12 µg bid) or tiotropium (18 µg od). Peripheral blood neutrophils were obtained at the start and at the end of the treatment, and production of superoxide anions and of LTB4 were evaluated as previously published. The results obtained showed a decrease in the unstimulated production of superoxide by isolated neutrophils in both groups, but tiotropium only was effective in modulating the production of LTB4, while formoterol caused an increased production of superoxide in response to fMLP, when compared to values obtained before treatment. In conclusion, tiotropium showed a better antiinflammatory activity profile when compared to formoterol in a clinical setting, reducing superoxide and LTB4 production by peripheral neutrophils obtained from COPD subjects.

Transcellular biosynthesis of cysteinyl leukotrienes in vivo during mouse peritoneal inflammation.

Leukotrienes (LTs) are lipid mediators of inflammation formed by enzymatic oxidation of arachidonic acid. One intriguing aspect of LT production is transcellular biosynthesis: cells expressing 5-lipoxygenase (5LO) form LTA(4) and transfer it to cells expressing LTA(4) hydrolase (LTA(4)H) or LTC(4) synthase (LTC(4)S) to produce LTB(4) or LTC(4). This process has been demonstrated in vivo for LTB(4), but not for cysteinyl LTs (cysLTs). We examined transcellular cysLT synthesis during zymosan-induced peritonitis, using bone marrow transplants with transgenic mice deficient in key enzymes of LT synthesis and analyzing all eicosanoids by liquid chromatography/tandem mass spectrometry. WT mice time-dependently produced LTB(4) and cysLTs (LTC(4), LTD(4), and LTE(4)). 5LO(-/-) mice were incapable of producing LTs. WT bone marrow cells restored this biosynthetic ability, but 5LO(-/-) bone marrow did not rescue LT synthesis in irradiated WT mice, demonstrating that bone marrow-derived cells are the ultimate source of all LTs in this model. Total levels of 5LO-derived products were comparable in LTA(4)H(-/-) and WT mice, but were reduced in LTC(4)S(-/-) animals. No differences in prostaglandin production were observed between these transgenic or chimeric mice. Bone marrow cells from LTA(4)H(-/-) or LTC(4)S(-/-) mice injected into 5LO(-/-) mice restored the ability to synthesize LTB(4) and cysLTs, providing unequivocal evidence of efficient transcellular biosynthesis of cysLTs. These results highlight the potential relevance of transcellular exchange of LTA(4) for the synthesis of LTs mediating biological activities during inflammatory events in vivo.

Bioactive Compounds in Edible Oils and Their Role in Oxidative Stress and Inflammation.

Diet and inflammatory response are recognized as strictly related, and interest in exploring the potential of edible fats and oils for health and chronic diseases is emerging worldwide. Polyunsaturated fatty acids (PUFAs) present in fish oil (FO), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may be partly converted into oxygenated bioactive lipids with anti-inflammatory and/or pro-resolving activities. Moreover, the co-presence of phenolic compounds and vitamins in edible oils may prevent the development of chronic diseases by their anti-inflammatory, antioxidant, neuroprotective, and immunomodulatory activities. Finally, a high content in mono-unsaturated fatty acids may improve the serum lipid profile and decrease the alterations caused by the oxidized low-density lipoproteins and free radicals. The present review aims to highlight the role of lipids and other bioactive compounds contained in edible oils on oxidative stress and inflammation, focusing on critical and controversial issues that recently emerged, and pointing to the opposing role often played by edible oils components and their oxidized metabolites.

Effects of Mediterranean Diet or Low-Fat Diet on Blood Fatty Acids in Patients with Coronary Heart Disease. A Randomized Intervention Study.

The Mediterranean diet (MD) prevents cardiovascular disease by different putative mechanisms, including modifications in the blood fatty acid (FA) profile. Polytherapy for secondary cardiovascular prevention might mask the effect of MD on the FA profile. This study was aimed to assess whether MD, in comparison with a low-fat diet (LFD), favorably modifies the blood FA profile in patients with coronary heart disease (CHD) on polytherapy. One hundred and twenty patients with a recent history of coronary stenting, randomized to MD or to LFD, completed 3 months of this open-label dietary intervention study. Diet Mediterranean-ness was evaluated using the Mediterranean Diet Adherence Screener (MeDAS) score. Both diets significantly reduced saturated FA (p < 0.01). Putative favorable changes in total n-3 FA (p = 0.03) and eicosapentaenoic acid plus docosahexaenoic acid (EPA + DHA; p = 0.04) were significantly larger with MD than with LFD. At 3 months, in the whole cohort, the MeDAS score correlated inversely with palmitic acid (R = -0.21, p = 0.02), and with palmitoleic acid (R = -0.32, p = 0.007), and positively with total n-3 FA (R = 0.19, p = 0.03), EPA (R = 0.28, p = 0.002), and EPA + DHA (R = 0.21, p = 0.02). In CHD patients on polytherapy, both MD and LFD shift FA blood composition towards a healthier profile, with a more favorable effect of MD on omega-3 levels.

Blood Fatty Acids Profile in MIS-C Children.

MIS-C (multisystem inflammatory syndrome in children) linked to SARS-CoV-2 infection, is a pathological state observed in subjects younger than 21 years old with evidence of either current SARS-CoV-2 infection or exposure within the 4 weeks prior to the onset of symptoms, the presence of documented fever, elevated markers of inflammation, at least two signs of multisystem involvement, and, finally, lack of an alternative diagnosis. They share with adult COVID-19 patients the presence of altered markers of inflammation, but unlike most adults the symptoms are not pulmonary but are affecting several organs. Lipid mediators arising from polyunsaturated fatty acids (PUFA) play an important role in the inflammatory response, with arachidonic acid-derived compounds, such as prostaglandins and leukotrienes, mainly pro-inflammatory and ω3 PUFA metabolites such as resolvins and protectins, showing anti-inflammatory and pro-resolution activities. In order to assess potential alterations of these FA, we evaluated the blood fatty acid profile of MIS-C children at admission to the hospital, together with biochemical, metabolic and clinical assessment. All the patients enrolled showed altered inflammatory parameters with fibrinogen, D-dimer, NT-proBNP, ferritin, aspartate aminotransferase (AST), C-reactive protein (CRP) and TrygIndex levels over the reference values in all the subjects under observation, while albumin and HDL-cholesterol resulted below the normal range. Interestingly, linoleic acid (LA), arachidonic acid (AA) and the ω3 PUFA docosahexaenoic acid (DHA) results were lower in our study when compared to relative amounts reported in the other studies, including from our own laboratory. This significant alteration is pointing out to a potential depletion of these PUFA as a result of the systemic inflammatory condition typical of these patients, suggesting that LA- and AA-derived metabolites may play a critical role in this pathological state, while ω3 PUFA-derived pro-resolution metabolites in these subjects may not be able to provide a timely, physiological counterbalance to the formation of pro-inflammatory lipid mediators. In conclusion, this observational study provides evidence of FA alterations in MIS-C children, suggesting a significant contribution of ω6 FA to the observed inflammatory state, and supporting a potential dietary intervention to restore an appropriate balance among the FAs capable of promoting the resolution of the observed inflammatory condition.