Platelet Activating Factor (PAF): A Mediator of Inflammation

Predictive and therapeutic value of lipoprotein-associated phospholipaseA2 in sarcopenia in chronic obstructive pulmonary disease

BACKGROUND

Sarcopenia, characterized by progressive muscle dysfunction, is a common complication of chronic obstructive pulmonary disease (COPD). Our previous study revealed serum Lipoprotein-associated phospholipaseA2 (Lp-PLA2) level significantly increased in COPD and associated with exercise tolerance. This study further investigated the functions and target potential of Lp-PLA2 for sarcopenia in COPD.

METHODS

The circulating Lp-PLA2 level/enzyme activity in COPD patients and age-matched healthy volunteers were measured. Clinical parameters on skeletal muscle were measured and their correlations with Lp-PLA2 were analyzed. We explored the involvement of Lp-PLA2 in vivo and treatment effectiveness of darapladib (a specific Lp-PLA2 inhibitor) in CS-induced muscle dysfunction models.

RESULTS

Circulating Lp-PLA2 level/enzyme activity was elevated in COPD patients compared with healthy controls, negatively associated with skeletal muscle mass and function. In CS-induced muscle dysfunction murine models, up-regulated serum Lp-PLA2 level/enzyme activity was verified again. In CS-exposed mouse models, darapladib treatment reversed muscle mass loss and muscle dysfunction, meanwhile rescued upregulation of MuRF1 and atrogin-1, and activation of inflammatory factors, oxidant enzymes and NF-κB signaling.

CONCLUSIONS

Lp-PLA2 could be a potential indicator for sarcopenia in COPD. Darapladib, a Lp-PLA2 inhibitor, can alleviate CS-induced skeletal muscle dysfunction and represents a potential therapeutic for sarcopenia in COPD.

SELENOI Functions as a Key Modulator of Ferroptosis Pathway in Colitis and Colorectal Cancer

Ferroptosis plays important roles both in normal physiology and multiple human diseases. It is well known that selenoprotein named glutathione peroxidase 4 (GPX4) is a crucial regulator for ferroptosis. However, it remains unknown whether other selenoproteins responsible for the regulation of ferroptosis, particularly in gut diseases. In this study, it is observed that Selenoprotein I (Selenoi) prevents ferroptosis by maintaining ether lipids homeostasis. Specific deletion of Selenoi in intestinal epithelial cells induced the occurrence of ferroptosis, leading to impaired intestinal regeneration and compromised colonic tumor growth. Mechanistically, Selenoi deficiency causes a remarkable decrease in ether-linked phosphatidylethanolamine (ePE) and a marked increase in ether-linked phosphatidylcholine (ePC). The imbalance of ePE and ePC results in the upregulation of phospholipase A2, group IIA (Pla2g2a) and group V (Pla2g5), as well as arachidonate-15-lipoxygenase (Alox15), which give rise to excessive lipid peroxidation. Knockdown of PLA2G2A, PLA2G5, or ALOX15 can reverse the ferroptosis phenotypes, suggesting that they are downstream effectors of SELENOI. Strikingly, GPX4 overexpression cannot rescue the ferroptosis phenotypes of SELENOI-knockdown cells, while SELENOI overexpression can partially rescue GPX4-knockdown-induced ferroptosis. It suggests that SELENOI prevents ferroptosis independent of GPX4. Taken together, these findings strongly support the notion that SELENOI functions as a novel suppressor of ferroptosis during colitis and colon tumorigenesis.

Recent advancements in deciphering the therapeutic properties of plant secondary metabolites: phenolics, terpenes, and alkaloids

Plants produce a diverse range of secondary metabolites that serve as defense compounds against a wide range of biotic and abiotic stresses. In addition, their potential curative attributes in addressing various human diseases render them valuable in the development of pharmaceutical drugs. Different secondary metabolites including phenolics, terpenes, and alkaloids have been investigated for their antioxidant and therapeutic potential. A vast number of studies evaluated the specific compounds that possess crucial medicinal properties (such as antioxidative, anti-inflammatory, anticancerous, and antibacterial), their mechanisms of action, and potential applications in pharmacology and medicine. Therefore, an attempt has been made to characterize the secondary metabolites studied in medicinal plants, a brief overview of their biosynthetic pathways and mechanisms of action along with their signaling pathways by which they regulate various oxidative stress-related diseases in humans. Additionally, the biotechnological approaches employed to enhance their production have also been discussed. The outcome of the present review will lead to the development of novel and effective phytomedicines in the treatment of various ailments.

Bioactive peptides in dry-cured ham: A comprehensive review of preparation methods, metabolic stability, safety, health benefits, and regulatory frameworks

Dry-cured hams contain abundant bioactive peptides with significant potential for the development of functional foods. However, the limited bioavailability of food-derived bioactive peptides has hindered their utilization in health food development. Moreover, there is insufficient regulatory information regarding bioactive peptides and related products globally. This review summarizes diverse bioactive peptides derived from dry-cured ham and by-products originating from various countries and regions. The bioactivity, preparation techniques, bioavailability, and metabolic stability of these bioactive peptides are described, as well as the legal and regulatory frameworks in various countries. The primary objectives of this review are to dig deeper into the functionality of dry-cured ham and provide theoretical support for the commercialization of bioactive peptides from food sources, especially the dry-cured ham.

Lysophospholipid Acyltransferase 9 Promotes Emphysema Formation via Platelet-activating Factor

Cigarette smoking is known to be the leading cause of chronic obstructive pulmonary disease (COPD). However, the detailed mechanisms have not been elucidated. PAF (platelet-activating factor), a potent inflammatory mediator, is involved in the pathogenesis of various respiratory diseases such as bronchial asthma and COPD. We focused on LPLAT9 (lysophospholipid acyltransferase 9), a biosynthetic enzyme of PAF, in the pathogenesis of COPD. LPLAT9 gene expression was observed in excised COPD lungs and single-cell RNA sequencing data of alveolar macrophages (AMs). LPLAT9 was predominant and upregulated in AMs, particularly monocyte-derived AMs, in patients with COPD. To identify the function of LPLAT9/PAF in AMs in the pathogenesis of COPD, we exposed systemic LPLAT9-knockout (LPALT9-/-) mice to cigarette smoke (CS). CS increased the number of AMs, especially the monocyte-derived fraction, which secreted MMP12 (matrix metalloprotease 12). Also, CS augmented LPLAT9 phosphorylation/activation on macrophages and, subsequently, PAF synthesis in the lung. The LPLAT9-/- mouse lung showed reduced PAF production after CS exposure. Intratracheal PAF administration accumulated AMs by increasing MCP1 (monocyte chemoattractant protein-1). After CS exposure, AM accumulation and subsequent pulmonary emphysema, a primary pathologic change of COPD, were reduced in LPALT9-/- mice compared with LPLAT9+/+ mice. Notably, these phenotypes were again worsened by LPLAT9+/+ bone marrow transplantation in LPALT9-/- mice. Thus, CS-induced LPLAT9 activation in monocyte-derived AMs aggravated pulmonary emphysema via PAF-induced further accumulation of AMs. These results suggest that PAF synthesized by LPLAT9 has an important role in the pathogenesis of COPD.

Differential expression of serum TM, PAF, and CD62P in patients with autologous arteriovenous fistula and the correlation with vascular access function

BACKGROUND

End-stage renal disease (ESRD) is the final stage of chronic kidney disease (CKD).

AIMS

We aimed to analyze the expression differences of serum thrombomodulin (TM), platelet-activating factor (PAF), and P-selectin (CD62P) in patients with autologous arteriovenous fistula (AVF) and the correlation with vascular access function.

METHODS

The case data were retrospectively analyzed. Moreover, 160 patients with AVF maintenance hemodialysis were selected as the AVF group, and 150 healthy participants were selected as the healthy control group. According to the function of vascular access, patients in the AVF group were divided into Group A (n = 50, after the first establishment of AVF), Group B (n = 64, normal vascular access function after hemodialysis treatment), and Group C (n = 46, vascular access failure). Pearson analysis was conducted to explore the correlation between serum TM, PAF, CD62P content, and vascular pathological examination indicators, to evaluate the value of TM, PAF, and CD62P levels in predicting vascular access failure in patients with AVF.

RESULTS AND DISCUSSION

The serum levels of TM, PAF, and CD62P were positively correlated with the expressions of CD68 and MCP-1, respectively (p < .001). Serum TM was positively correlated with the levels of PAF and CD62P (p < .001), and PAF was positively correlated with the levels of CD62P (p < .001), respectively. Serum levels of TM, PAF and CD62P were risk factors for vascular access failure in AVF patients (p < .05). The area under the curve of serum TM, PAF and CD62P levels in predicting vascular access failure in AVF patients was 0.879.

CONCLUSION

The serum levels of TM, PAF, and CD62P in AVF patients were correlated with the vascular access function of AVF patients, which was very important for maintaining the stability of vascular access function, and had certain value in predicting vascular access failure/disorder in AVF patients, and could be popularized and applied.

Severe Type 2 Inflammation Leads to High Platelet-Activating-Factor-Associated Pathology in Chronic Rhinosinusitis with Nasal Polyps-A Hierarchical Cluster Analysis Using Bulk RNA Barcoding and Sequencing

Platelet-activating factor (PAF) is a phospholipid-derived inflammatory mediator that triggers various inflammatory conditions, including eosinophil activation and recruitment. This study aimed to evaluate the expressions of PAF-metabolism-associated genes, namely genes coding the enzymes involved in PAF synthesis (LPCAT1, LPCAT2, LPCAT3, and LPCAT4), PAF degradation (PAFAH1B2, PAFAH1B3, and PAFAH2), and the gene for the PAF receptor (PTAFR) in subtypes of CRSwNP classified by clinical- or hierarchal-analysis-based classifications. Transcriptomic analysis using bulk RNA barcoding and sequencing (BRB-seq) was performed with CRSwNP, including eosinophilic CRS (ECRS) (n = 9), nonECRS (n = 8), ECRS with aspirin-exacerbated respiratory disease (Asp) (n = 3), and controls with a normal uncinate process mucosa (n = 6). PTAFR was only upregulated in ECRS and nonECRS. In the hierarchical cluster analysis with clusters 1 and 2 reflecting patients with low-to-moderate and high levels of type 2 inflammation, respectively, cluster 1 exhibited a significant downregulation of LPCAT2 and an upregulation of PTAFR expression, while cluster 2 showed an upregulation of LPCAT1, PAFAH1B2, and PTAFR and downregulation of PAFAH2 expression. Understanding this strong PAF-associated pathophysiology in the severe type 2 inflammation group could provide valuable insights into the treatment and management of CRSwNP.

The effects of IGF-1 and IGFBP-2 treatments on the atherosclerosis in the aorta and the coronary arteries of the high cholesterol diet-fed rabbits

Several studies have demonstrated suppression of aortic atherosclerosis by insulin like growth factor-1 (IGF-1) in hypercholesterolemic rabbits. Though a recent study has reported that IGF-1 exerts anti-atherogenic effects in coronary arteries, the mechanisms of IGF-1 in coronary arteries need to be further verified. Studies about insulin like growth factor binding protein-2 (IGFBP-2) in atherosclerosis are rarely. The objective of this study is to examine the effects of IGF-1 and IGFBP-2 on the atherosclerosis development in the aorta and coronary arteries of the high-cholesterol diet (HCD)-fed rabbits. New Zealand white rabbits were fed either normal chow (n = 5) or a diet containing 1.0 % cholesterol (n = 18) for 12 weeks. Cholesterol-fed rabbits were given IGF-1 or IGFBP-2 or saline intravenously (each n = 6) for 10 weeks. The results revealed that IGF-1 decreased total cholesterol (TC) and low-density lipoprotein (LDL) levels (p < 0.05), whereas IGFBP-2 did not. IGF-1 significantly attenuated atherosclerotic lesions and reduced accumulated macrophages within the coronary artery plaques, whereas IGFBP-2 deteriorated these changes. Moreover, IGF-1 reduced serum platelet-activating factor acetylhydrolase levels, C reactive protein (CRP), and inhibited the protein expression levels of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6). IGFBP-2 elevated serum 8-hydroxy-2'-deoxyguanosine levels, CRP, and promoted the protein expression levels of TNF-α and IL-6. In conclusion, IGF-1 can substantially suppress plaque formation in coronary arteries with a marked inhibition of macrophage accumulation likely via its anti-inflammatory properties, whereas IGFBP-2 plays an opposite effect on atherosclerosis. The present study highlighted a theoretical basis for pharmacological treatment of atherosclerosis.

Anaphylaxis mortality in the perioperative setting: Epidemiology, elicitors, risk factors and knowledge gaps

Perioperative anaphylaxis (PA) is a severe condition that can be fatal, but data on PA mortality are scarce. The aim of this article is to review the epidemiology, elicitors and risk factors for PA mortality and identify knowledge gaps and areas for improvement regarding the management of severe PA. PA affects about 100 cases per million procedures. Mortality is rare, estimated at 3 to 5 cases per million procedures, but the PA mortality rate is higher than for other anaphylaxis aetiologies, at 1.4% to 4.8%. However, the data are incomplete. Published data mention neuromuscular blocking agents and antibiotics, mainly penicillin and cefazolin, as the main causes of fatal PA. Reported risk factors for fatal PA vary in different countries. Most frequently occurring comorbidities are obesity, male gender, cardiovascular diseases and ongoing treatment with beta-blockers. However, there are no clues about how these factors interact and the impact of individual risk factors. The pathophysiology of fatal PA is still not completely known. Genetic factors such as deficiency in PAF-acetyl hydrolase and hereditary alpha-tryptasemia, have been reported as modulators of severe anaphylaxis and possible targets for specific treatments. Our review underlines unmet needs in the field of fatal PA. Although we confirmed the need for timely administration of an adequate dose of adrenaline and the proper infusion of fluids, there is no evidence-based data on the proper dose of intravenous titrated adrenaline and which clinical manifestations would flag the need for fluid therapy. There are no large clinical studies supporting the administration of alternative vasopressors, such as glucagon and methylene blue. Further research on pathophysiological mechanisms of PA and its severity may address these issues and help clinicians to define new therapeutic approaches.

B-cell-activating factor (BAFF) and platelet-activating factor (PAF) in pregnancies complicated by maternal obesity and diabetes: a preliminary study

OBJECTIVE

In pregnancies complicated by maternal obesity and diabetes, a disruption in inflammatory mediators occurs, resulting in endothelial microvascular dysfunction, oxidative stress, tissue damage, and maternal and feto-neonatal complications. To outline this proinflammatory status, an innovative approach is represented by the measurement of proinflammatory cytokines. Among these biomarkers, B-cell-activating factor (BAFF) and platelet-activating factor (PAF) play a key role in metabolic regulation, immune response to infections, tissue homeostasis, and "food-related inflammation." The aim of the present study is to investigate the blood expression of BAFF and PAF in a cohort of pregnant women affected by obesity and diabetes compared with a control group of healthy pregnant women.

METHODS

A prospective longitudinal cohort study has been conducted on pregnant women referred to Fondazione Policlinico Universitario Gemelli IRCCS in Rome. For each pregnant woman, a capillary sample was collected with a swab in three different consecutive evaluations carried out in the three trimesters of pregnancy.

RESULTS

A total of 77 pregnant women have been enrolled. No significant differences in BAFF and PAF levels were longitudinally observed between groups. Focusing on the exposed group, in the third trimester of pregnancy, both PAF and BAFF levels were lower than the basal time. Among the selected group of patients who developed Gestational Diabetes, only PAF values were longitudinally lower when compared to other groups. The multivariate analysis showed that BAFF levels were positively correlated with thyroid-stimulating hormone levels. No macrosomia, no shoulder dystocia, no major perineal lacerations at birth, and no intrauterine growth restriction were observed in the whole population.

CONCLUSIONS

This study supports the involvement of metabolic and proinflammatory biomarkers in the mechanisms related to pregnancy complications. Improving a good metabolic environment for obese and diabetic pregnant women could break the vicious cycle connecting inflammation, oxidative stress, and metabolic disorders.

Anti-heat shock protein 10 IgG in chronic spontaneous urticaria: Relation with miRNA-101-5p and platelet-activating factor

BACKGROUND

Anti-heat shock protein (HSP) autoantibodies are detected in autoimmune diseases. We sought to ascertain whether anti-HSP10 IgG is present in patients with CSU and to elucidate the role of HSP10 in CSU pathogenesis.

METHOD

Using a human proteome microarray, six potential autoantibodies had higher expression in 10 CSU samples compared with 10 normal controls (NCs). Among them, HSP10 IgG autoantibody was quantified by immune dot-blot assay in sera from 86 CSU patients and 44 NCs. The serum levels of HSP10 and microRNA-101-5p were measured in CSU patients and NCs. The effects of HSP10 and miR-101-5p on mast cell degranulation in response to IgE, compound 48/80, and platelet-activating factor (PAF) were investigated.

RESULTS

CSU patients had higher IgG positivity to HSP10 (40.7% vs. 11.4%, p = .001), lower serum HSP10 levels (5.8 ± 3.6 vs. 12.2 ± 6.6 pg/mL, p < .001) than in NCs, and their urticaria severity was associated with anti-HSP10 IgG positivity, while HSP10 levels were related to urticaria control status. MiR-101-5p was increased in CSU patients. PAF enhanced IL4 production in PBMCs from CSU patients. IL-4 upregulated miR-101-5p and reduced HSP10 expression in keratinocytes. Transfection of miR-101-5p reduced HSP10 expression in keratinocytes. MiR-101-5p promoted PAF-induced mast cell degranulation, while HSP10 specifically prevented it.

CONCLUSION

A new autoantibody, anti-HSP10 IgG was detected in CSU patients, which showed a significant correlation with UAS7 scores. A decreased serum HSP10 level was associated with upregulation of miR-101-5p due to increased IL-4 and PAF in CSU patients. Modulation of miR-101-5p and HSP10 may be a novel therapeutic approach for CSU.

Associations of phase angle with platelet-activating factor metabolism and related dietary factors in healthy volunteers

Introduction

Phase angle (PA) is derived from bioelectrical impedance analysis (BIA). It reflects cell membrane function and decreases in disease. It is affected by inflammation, oxidative stress, and diet. Platelet-activating factor (PAF) is a potent inflammatory lipid mediator. Its levels, along with the activity of its metabolic enzymes, including CDP-choline:1-alkyl-2-acetyl-sn-glycerol-cholinephosphotransferase, acetyl-CoA:lyso-PAF-acetyltransferases, and PAF-AH/Lp-PLA2 are also related to dietary factors, such as the dietary antioxidant capacity (DAC). The aim of the study was to estimate whether the PAF metabolic circuit and related dietary factors are associated with PA in healthy volunteers.

Methods

In healthy subjects, PAF, its metabolic enzyme activity, and erythrocyte fatty acids were measured, while desaturases were estimated. Food-frequency questionnaires and recalls were used, and food groups, macronutrient intake, MedDietScore, and DAC were assessed. Lifestyle and biochemical variables were collected. DXA and BIA measurements were performed.

Results

Lp-PLA2 activity was positively associated with PA (rho = 0.651, p < 0.001, total population; rho = 0.780, p < 0.001, women), while PAF levels were negatively associated with PA only in men (partial rho = -0.627, p = 0.012) and inversely related to DAC. Estimated desaturase 6 was inversely associated with PA (rho = -0.404, p = 0.01, total sample). Moreover, the DAC correlated positively with PA (rho = 0.513, p = 0.03, women). All correlations were adjusted for age, body mass index, and sex (if applicable).

Conclusion

PA is associated with PAF levels and Lp-PLA2 activity in a gender-dependent fashion, indicating the involvement of PAF in cell membrane impairment. The relationship of PA with DAC suggests a protective effect of antioxidants on cellular health, considering that antioxidants may inhibit PAF generation.

Novel Cyclopentathiophene Carboxamide Derivatives as PAFR Antagonists for Treating Ocular Diseases, Allergies, and Inflammation-Related Diseases

Provided herein are novel cyclopentathiophene carboxamide derivatives as platelet activating factor receptor (PAFR) antagonists, pharmaceutical compositions, use of such compounds in treating ocular diseases, allergies, and inflammation-related diseases, and processes for preparing such compounds.

Platelet-activating factor as an endogenous cofactor of food anaphylaxis

Anaphylaxis is a severe, acute, life-threatening generalized or systemic hypersensitivity reaction. The incidence of anaphylaxis is increasing worldwide, with medications and food contributing to most cases. Physical exercise, acute infections, drugs, alcohol, and menstruation are the external cofactors associated with more severe systemic reaction. The aim of this review is to show that platelet-activating factor contributes to the development of severe anaphylactic reaction, and even to anaphylactic shock.

Mast Cells and Basophils in IgE-Independent Anaphylaxis

Anaphylaxis is a life-threatening or even fatal systemic hypersensitivity reaction. The incidence of anaphylaxis has risen at an alarming rate in the past decades in the majority of countries. Generally, the most common causes of severe or fatal anaphylaxis are medication, foods and Hymenoptera venoms. Anaphylactic reactions are characterized by the activation of mast cells and basophils and the release of mediators. These cells express a variety of receptors that enable them to respond to a wide range of stimulants. Most studies of anaphylaxis focus on IgE-dependent reactions. The mast cell has long been regarded as the main effector cell involved in IgE-mediated anaphylaxis. This paper reviews IgE-independent anaphylaxis, with special emphasis on mast cells, basophils, anaphylactic mediators, risk factors, triggers, and management.

Platelet activation: a promoter for psoriasis and its comorbidity, cardiovascular disease

Psoriasis is a chronic inflammatory skin disease with a prevalence of 0.14% to 1.99%. The underlying pathology is mainly driven by the abnormal immune responses including activation of Th1, Th17, Th22 cells and secretion of cytokines. Patients with psoriasis are more likely to develop cardiovascular disease (CVD) which has been well recognized as a comorbidity of psoriasis. As mediators of hemostasis and thromboinflammation, platelets play an important part in CVD. However, less is known about their pathophysiological contribution to psoriasis and psoriasis-associated CVD. A comprehensive understanding of the role of platelet activation in psoriasis might pave the path for more accurate prediction of cardiovascular (CV) risk and provide new strategies for psoriasis management, which alleviates the increased CV burden associated with psoriasis. Here we review the available evidence about the biomarkers and mechanisms of platelet activation in psoriasis and the role of platelet activation in intriguing the common comorbidity, CVD. We further discussed the implications and efficacy of antiplatelet therapies in the treatment of psoriasis and prevention of psoriasis-associated CVD.

Extrinsic and Intrinsic Modulators of Anaphylaxis

The severity of anaphylaxis is determined by many factors. The allergenic source as well as the age of the affected individual and the route of allergen exposure encompass the major contributors of the clinical outcome. Moreover, the severity can be modulated further by intrinsic and extrinsic factors. Among these, the genetic predisposition, certain comorbidities such as uncontrolled asthma, and hormonal fluctuations have been proposed as intrinsic and antihypertensive medications or physical activity as extrinsic factors. Recent advances have highlighted immunologic pathways that may exacerbate the response to allergens through receptors on mast cells, basophils, platelets, and other granulocytes. Atopy, platelet-activating factor acetylhydrolase deficiency, hereditary alpha tryptasemia, and clonal mast cell disorders are examples associated with genetic alterations that may predispose to severe anaphylaxis. Identifying risk factors that lower the threshold of reactivity or increase the severity of multisystem reactions is important in the management of this patient population.

Cyclopentathiophene Carboxamide Derivatives as PAFR Antagonists for Treating Ocular Diseases, Allergies, and Inflammation-Related Disorders

Provided herein are cyclopentathiophene carboxamide derivatives as platelet activating factor receptor (PAFR) antagonists, pharmaceutical compositions, use of such compounds in treating ocular diseases, allergies, and inflammation-related disorders, and processes for preparing such compounds.

Protective Effect of Olive Oil Microconstituents in Atherosclerosis: Emphasis on PAF Implicated Atherosclerosis Theory

Atherosclerosis is a progressive vascular multifactorial process. The mechanisms underlining the initiating event of atheromatous plaque formation are inflammation and oxidation. Among the modifiable risk factors for cardiovascular diseases, diet and especially the Mediterranean diet (MedDiet), has been widely recognized as one of the healthiest dietary patterns. Olive oil (OO), the main source of the fatty components of the MedDiet is superior to the other "Mono-unsaturated fatty acids containing oils" due to the existence of specific microconstituents. In this review, the effects of OO microconstituents in atherosclerosis, based on data from in vitro and in vivo studies with special attention on their inhibitory activity against PAF (Platelet-Activating Factor) actions, are presented and critically discussed. In conclusion, we propose that the anti-atherogenic effect of OO is attributed to the synergistic action of its microconstituents, mainly polar lipids that act as PAF inhibitors, specific polyphenols and α-tocopherol that also exert anti-PAF activity. This beneficial effect, also mediated through anti-PAF action, can occur from microconstituents extracted from olive pomace, a toxic by-product of the OO production process that constitutes a significant ecological problem. Daily intake of moderate amounts of OO consumed in the context of a balanced diet is significant for healthy adults.

Secretory and Membrane-Associated Biomarkers of Mast Cell Activation and Proliferation

Mast cells (MCs) are immune cells distributed in many organs and tissues and involved in the pathogenesis of allergic and inflammatory diseases as a major source of pro-inflammatory and vasoactive mediators. MC-related disorders are heterogeneous conditions characterized by the proliferation of MC within tissues and/or MC hyper-reactivity that leads to the uncontrolled release of mediators. MC disorders include mastocytosis, a clonal disease characterized by tissue MC proliferation, and MC activation syndromes that can be primary (clonal), secondary (related to allergic disorders), or idiopathic. Diagnosis of MC disorders is difficult because symptoms are transient, unpredictable, and unspecific, and because these conditions mimic many other diseases. Validation of markers of MC activation in vivo will be useful to allow faster diagnosis and better management of MC disorders. Tryptase, being the most specific MC product, is a widely used biomarker of proliferation and activation. Other mediators, such as histamine, cysteinyl leukotrienes, and prostaglandin D2, are unstable molecules and have limitations in their assays. Surface MC markers, detected by flow cytometry, are useful for the identification of neoplastic MC in mastocytosis but, so far, none of them has been validated as a biomarker of MC activation. Further studies are needed to identify useful biomarkers of MC activation in vivo.