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Mast cells (MCs) are tissue cells that are derived from bone marrow stem cells that contribute to allergic reactions, inflammatory diseases, innate and adaptive immunity, autoimmunity, and mental disorders. MCs located near the meninges communicate with microglia through the production of mediators such as histamine and tryptase, but also through the secretion of IL-1, IL-6 and TNF, which can create pathological effects in the brain. Preformed chemical mediators of inflammation and tumor necrosis factor (TNF) are rapidly released from the granules of MCs, the only immune cells capable of storing the cytokine TNF, although it can also be produced later through mRNA. The role of MCs in nervous system diseases has been extensively studied and reported in the scientific literature; it is of great clinical interest. However, many of the published articles concern studies on animals (mainly rats or mice) and not on humans. MCs are known to interact with neuropeptides that mediate endothelial cell activation, resulting in central nervous system (CNS) inflammatory disorders. In the brain, MCs interact with neurons causing neuronal excitation with the production of neuropeptides and the release of inflammatory mediators such as cytokines and chemokines. This article explores the current understanding of MC activation by neuropeptide substance P (SP), corticotropin-releasing hormone (CRH), and neurotensin, and the role of pro-inflammatory cytokines, suggesting a therapeutic effect of the anti-inflammatory cytokines IL-37 and IL-38.

Much evidence suggests autoimmunity in the etiopathogenesis of periodontal disease. In fact, in periodontitis, there is antibody production against collagen, DNA, and IgG, as well as increased IgA expression, T cell dysfunction, high expression of class II MHC molecules on the surface of gingival epithelial cells in inflamed tissues, activation of NK cells, and the generation of antibodies against the azurophil granules of polymorphonuclear leukocytes. In general, direct activation of autoreactive immune cells and production of TNF can activate neutrophils to release pro-inflammatory enzymes with tissue damage in the gingiva. Gingival inflammation and, in the most serious cases, periodontitis, are mainly due to the dysbiosis of the commensal oral microbiota that triggers the immune system. This inflammatory pathological state can affect the periodontal ligament, bone, and the entire gingival tissue. Oral tolerance can be abrogated by some cytokines produced by epithelial cells and activated immune cells, including mast cells (MCs). Periodontal cells and inflammatory–immune cells, including mast cells (MCs), produce cytokines and chemokines, mediating local inflammation of the gingival, along with destruction of the periodontal ligament and alveolar bone. Immune-cell activation and recruitment can be induced by inflammatory cytokines, such as IL-1, TNF, IL-33, and bacterial products, including lipopolysaccharide (LPS). IL-1 and IL-33 are pleiotropic cytokines from members of the IL-1 family, which mediate inflammation of MCs and contribute to many key features of periodontitis and other inflammatory disorders. IL-33 activates several immune cells, including lymphocytes, Th2 cells, and MCs in both innate and acquired immunological diseases. The classic therapies for periodontitis include non-surgical periodontal treatment, surgery, antibiotics, anti-inflammatory drugs, and surgery, which have been only partially effective. Recently, a natural cytokine, IL-37, a member of the IL-1 family and a suppressor of IL-1b, has received considerable attention for the treatment of inflammatory diseases. In this article, we report that IL-37 may be an important and effective therapeutic cytokine that may inhibit periodontal inflammation. The purpose of this paper is to study the relationship between MCs, IL-1, IL-33, and IL-37 inhibition in acute and chronic inflamed gingival tissue.

Psoriasis (PS) is an autoimmune skin disease mediated by immune cells that typically presents inflammatory erythematous plaques, and it is associated with many comorbidities. PS exhibits excessive keratinocyte proliferation, and a high number of immune cells including macrophages, neutrophils, Th1 and Th17 lymphocytes, and mast cells (MCs). MCs are of hematopoietic origin, derived from bone marrow cells, which migrate, mature and reside in vascularized tissues. They can be activated by antigen provoking overexpression of pro-inflammatory cytokines and release a number of mediators including interleukin (IL)-1 and IL-33. IL-1, released by activated keratinocytes and MCs, stimulates skin macrophage to release IL-36, a powerful pro-inflammatory IL-1 family member. IL-36 mediates both innate and adaptive immunity, including chronic pro-inflammatory diseases such as psoriasis. Suppressing IL-36 results in a noticeable improvement in the treatment of psoriasis. IL-36 is inhibited by IL-36Ra which binds on to IL-36 receptor ligand, but suppression can also occur by binding IL-38 to the IL-36R receptor. IL-38 specifically binds only to IL-36R and inhibits human mononuclear cells stimulated with IL-36 in vitro, sharing the effect with IL-36Ra. Here, we report that inflammation in psoriasis is mediated by IL-1 generated by MCs, a process that activates macrophages to secrete pro-inflammatory IL-36 inhibited by IL-38. In this article we confirm that IL-38 and IL-37 cytokines emerge as inhibitors of inflammation in psoriasis and hold promise of an innovative therapeutic tool.

Coagulopathy represents one of the most important determinants of morbidity and mortality in coronavirus disease-19 (COVID-19). Whether standard thromboprophylaxis is sufficient or higher doses are needed, especially in severe patients, is unknown. To evaluate the safety of intermediate dose regimens of low-weight molecular heparin (LWMH) in COVID-19 patients with pneumonia, particularly in older patients. We retrospectively evaluated 105 hospitalized patients (61 M, 44 F; mean age 73.7 years) treated with subcutaneous enoxaparin: 80 mg/day in normal weight and mild-to-moderate impair or normal renal function; 40 mg/day in severe chronic renal failure or low bodyweight (

Polyphenols are ubiquitous in food and have long been recognized to possess antioxidant, anti-inflammatory and anticancer activities. Mast cells (MCs) are implicated in the pathogenesis of inflammatory diseases, allergy, autoimmunity and cancer. MCs derive from hematopoietic progenitor cells, reside virtually in all vascularized tissue and are activated by crosslinking of FceRI-bound IgE (at very high affinity: 1 × 1010 M-1) with multivalent antigen. MCs in cytoplasmic granules release preformed chemical mediators, and also they can release lipid mediators and cytokines/chemokines without degranulation. Luteolin, 3’,4’,5,7-tetrahydroxyflavone, is a flavonoid contained in many kinds of plants including vegetables and fruits. This anti-oxidant product inhibits interleukin (IL)-6, IL-8 and vascular endothelial growth factor (VEGF) production from tumor necrosis factor (TNF)-triggered keratinocytes, and is a candidate for use in alternative therapies in the treatment of inflammatory skin disorders. Quercetin (3,3’,4’,5,7-pentahydroxyflavone) is a ubiquitous flavonoid which exhibits anti-cancer, anti-oxidative and anti-inflammatory properties and causes a reduction in the availability of nitrite that influences vascular function. Quercetin exerts physiological functions though the interaction with phosphatidylinositol-3-phosphate kinase (PI3K), mitogen-activated protein kinase (MAPK), extracellular signal regulated kinase (ERK), kinase (MEK) 1, and others, and has a negative effect on FceRI cross-linking and other activating receptors on mast cells. In this article we report for the first time the interrelationship between mast cells and polyphenols.

The aim of this study was to evaluate the role of mast cells (MCs) in allograft rejection, eventually inhibited by IL-37. Immune cells including MCs participate in allograft rejection by generating IL-1, IL-33, TNF and other cytokines. We evaluated allograft rejection on the experience of our experimental data and using the relevant literature. MCs are involved in initiation and regulation of innate and adaptive immune responses-pathways. MCs are important pro-inflammatory cells which express high-affinity receptor FceRI and can be activated by IgE and some pro-inflammatory cytokines, such as IL-1 and IL-33. The cross-linkage of high affinity IgE receptor on MCs by antigen ligation has a crucial role in allergy, asthma, anaphylaxis, cancer and allograft rejection. MCs mediate immunity in organ transplant, leading to the activation of allospecific T cells implicated in the rejection and generate pro-inflammatory cytokines/chemokines. IL-1 pro-inflammatory cytokine family members released by MCs mediate allograft rejection and inflammation. IL-37 is also an IL-1 family member generated by macrophage cell line in small amounts, which binds to IL-18Rα and produces an anti-inflammatory effect. IL-37 provokes the inhibition of TLR signaling, TLR-induced mTOR and (MyD88)-mediated responses, suppressing pro-inflammatory IL-1 family members and increasing IL-10. IL-37 inhibition offers the opportunity to immunologically modulate MCs, by suppressing their production of IL-1 family members and reducing the risk of allograft rejection, resulting as a potential good therapeutic new cytokine. Here, we report the relationship between inflammatory MCs, allograft rejection and pro-inflammatory and anti-inflammatory IL-37.

Migraine is a common painful neurovascular disorder usually associated with several symptoms, such as photophobia, phonophobia, nausea, vomiting and inflammation, and involves immune cells. Mast cells (MCs) are immune cells derived from hematopoietic pluripotent stem cells which migrate and mature close to epithelial, blood vessels, and nerves. In almost all vascularized tissues there are MCs that produce, contain and release biologically active products including cytokines, arachidonic acid compounds, and proteases. In addition, MCs participate in innate and adaptive immune responses. Innate responses in the central nervous system (CNS) occur during neuroinflammatory phenomena, including migraine. Antigens found in the environment have a crucial role in inflammatory response, causing a broad range of diseases including migraine. They can be recognized by several innate immune cells, such as macrophages, microglia, dendritic cells and MCs, which can be activated trough Toll-like receptor (TLR) signaling. MCs reside close to primary nociceptive neurons, associate with nerves, and are capable of triggering local inflammation. MCs are involved in the pathophysiology of various tissues and organs, especially where there is an increase of angiogenesis. Activated MCs release preformed mediators include histamine, heparin, proteases (tryptase, chimase), hydrolases, cathepsin, carboxypeptidases, and peroxidase, and they also generate pro-inflammatory cytokines/chemokines. In addition, activated macrophages, microglia and MCs in the CNS release pro-inflammatory cytokines which provoke an increase of arachidonic acid product levels and lead to migraine and other neurological manifestations including fatigue, nausea, headaches and brain fog. Innate immunity and pro-inflammatory interleukin (IL)-1 cytokine family members can be inhibited by IL-37, a relatively new member of the IL-1 family. In this article, we report that some pro-inflammatory cytokines inducing migraine may be inhibited by IL-37, a natural suppressor of inflammation, and innate and acquired immunity.

The purpose of this article is to study the involvement of inflammatory mast cells (MCs) in depression which may be inhibited by IL-37. We evaluate mast cells in depression on the basis of our previous experimental data, and using the most relevant studies reported in the literature. Dysfunction of mood, feelings, and thoughts is a major risk factor for several metabolic diseases and may influence the physiology of the body leading to depression. Depression, present in mastocytosis, is an important endogenous process that promotes the activation of meningeal cell receptors through a low-grade neurogenic chronic inflammation, and MCs. Mast cells are localized along meningeal blood vessels and connective tissues, as well as between the ganglion cells and nerve fibers. They are present in the hypothalamus of mammalian brains capable of communication with nerves. MCs are classically activated by binding to IgE cross-link FceRI high-affinity receptor leading to release a plethora of mediators responsible for the generation of inflammatory cytokines. Corticotropin-releasing hormone (CRH), produced by MCs, has been found in microglial cells where it regulates immune cells and contributes to the pathogenesis of neurodegenerative diseases including depression. Inflammatory cytokines released by MCs aggravate depression and could be partially inhibited by IL-37. A detailed understanding of the interaction between the immune system, including MCs and depression, is necessary in order to address an effective therapy which could include IL-37. As a consequence, the concepts reviewed here have treatment implications.

Spores and fungal fragments found in indoor and outdoor environments originate from opportunistic fungi and they can contribute to inflammatory responses, causing a broad range of symptoms. Papers were selected and reviewed with an emphasis on the molecular mechanisms involved in the effect of fungi on immune cells, especially mast cells (MCs). Fungi can bind to antibodies and complement them, allowing them to be recognized by cells of the innate immune system, including macrophages, dendritic cells, and MCs, which are then stimulated via Toll-like receptor signaling. Fungi can cause diseases mediated by MCs and aggravate allergic inflammation. Immunosuppressed subjects can be particularly susceptible to developing diseases caused by opportunistic fungi. Mold also liberates mycotoxins that could be on volatile spores and stimulate MCs to secrete pro-inflammatory cytokines/chemokines, but this mechanism is not known. Fungi can activate the immune system directly or through mycotoxins, leading to stimulation of immune cells and chronic neuroinflammatory symptoms. Some of these processes may be inhibited by the new anti-inflammatory cytokine interleukin 37.

Background Fibrosis involves the activation of inflammatory cells, leading to a decrease in physiological function of the affected organ or tissue. Aims To update and synthesize relevant information concerning fibrosis into a new hypothesis to explain the pathogenesis of fibrosis and propose potential novel therapeutic approaches. Materials and methods Literature was reviewed and relevant information is discussed in the context of the pathogenesis of fibrosis. Results A number of cytokines and their mRNA are involved in the circulatory system and in organs of patients with fibrotic tissues. The profibrotic cytokines are generated by several activated immune cells, including fibroblasts and mast cells (MCs), which are important for tissue inflammatory responses to different types of injury. MC-derived TNF, IL-1, and IL-33 contribute crucially to the initiation of a cascade of the host defence mechanism(s), leading to the fibrosis process. Inhibition of TNF and inflammatory cytokines may slow the progression of fibrosis and improve the pathological status of the affected subject. IL-37 is generated by various types of immune cells and is an IL-1 family member protein. IL-37 is not a receptor antagonist; it binds IL-18 receptor alpha (IL-18Rα) and delivers the inhibitory signal by using TIR8. It has been shown that IL-37 can be protective in inflammation and injury, and inhibits both innate and adaptive immunity. Discussion IL-37 may be useful for suppression of inflammatory diseases induced by inhibiting MyD88-dependent TLR signalling. In addition, IL-37 downregulates NF-κB induced by TLR2 or TLR4 through a mechanism dependent on IL-18Rα. Conclusion This review summarizes current knowledge on the role of MC in inflammation and tissue/organ fibrosis, with a focus on the therapeutic potential of IL-37-targeting cytokines.

Mast cells (MCs) promote guest immune responses to parasites and play a critical role in allergic and inflammatory reactions. Once they have been activated, MCs release highly inflammatory compounds that can provoke serious pathologic signs that can lead to death. MCs generate a number of preformed, de novo synthesized compounds and inflammatory cytokine/chemokine synthesis in response to the high-affinity (Kd=10-10 M) immunoglobulin E receptor triggering. Circulating MC progenitors migrate into arterial intima and develop lesions, mediating inflammation. They are involved in several disorders, including metabolic diseases, such as type 2 diabetes mellitus, in which endothelial cells release several inflammatory compounds during acute and chronic vascular damage. Certain inflammatory cytokines, such as interleukin (IL)-1 and IL-33, not only are produced by MCs but also may activate them. These effects mediate systemic inflammatory responses in metabolic disorders. Proinflammatory cytokines, such as tumor necrosis factor, IL-33 and IL-6, secreted by MCs and other immune cells, contribute to insulin resistance by activating kinases. IL-37 (IL-1 family member 7), one of the latest cytokines discovered, binds the IL-18 receptor alpha (IL-18Rα) chain and suppresses innate and acquired immunity, with a therapeutic effect. It also inhibits cytokine levels, including IL-6, IL-18, IL-33, tumor necrosis factor and IL-1, and may improve insulin production and, therefore, the pathogenesis of diabetes, stroke and cardiovascular health. This describes a new concept of inhibition of and cure for inflammatory diseases. However, the safety, dosage and tolerability of this novel therapeutic agent, IL-37, still remains to be determined.

Mast cells (MCs) are implicated in an array of diseases, especially those involving a mucosal surface, including intestine. On appropriate activation from cytoplasmatic granules, MCs release preformed chemical mediators and generate inflammatory lipids and cytokines/chemokines. Intracellular signal and Lyn activation pathways can cause the degranulation of MCs and the generation of lipid mediators and cytokines/chemokines. MCs undergo maturation and polarization in gut mucosal surfaces where they are constitutively present, and can alter intestinal permeability, an important factor in many inflammatory mucosal disorders including autoimmune diseases. On the other hand, since they are immununosuppressive, MCs have potential anti-inflammatory properties by producing TGF-β1, interleukin (IL)-4, IL-10, IL-13 and histamine. In addition, MC chymase, located in the sub-mucosa, acts on intestinal permeability by protecting the bowel. To carry the inflammatory response, MCs need to be attracted by CC chemokines such as RANTES (CCL5) and MCP-1(CCL2), an effect absent in genetically W/Wv mast cell-deficient mice, where the inflammatory reaction is not present. Here, we focused our attention on recent findings regarding how MCs can initiate and develop the cellular immune response in the gut and mediate inflammation, an effect that can be inhibited by IL-37. These studies contribute to clarify the mechanisms by which MCs profoundly affect immunity and inflammation of the intestine.

Mast cells are essential not only for allergies but also for innate and acquired immunity, autoimmunity and inflammation, and they are recognized as a new type of immunoregulatory cells capable of producing different cytokines. Natural compounds have long been recognized to possess anti-inflammatory, antioxidant and anticancergenic activity. Quercitin is an inhibitor for mast cells and is a potent antioxidant, cytoprotective and anti-inflammatory compound and has a negative effect on intracellular regulator signal events initiated by FceRI receptor cross-linking and other activating receptors on mast cells. These observations candidate quercitin as a therapeutic compound in association with other therapeutic molecules. Capsaicin is a compound derived from peppers, especially capsicum, and is involved in stimulating circulation aiding digestion and relieving pain. Capsaicin receptor sub type I (VRI) is expressing in neurons and is present in a number of brain nuclei and in non-neuronal tissues, mediating inflammatory response. Capsaicin is involved in migraine, allergic symptoms, arthritis pain and gastric secretion. In this paper we review the biological effects of quercitin and capsaicin.

Bacteria and their products, such as LPS, act on mast cells (MCs) to induce the secretion of multiple cytokines, including IL-1, TNF, IL-18 and IL-33, which can be dosed in the site of infected tissues. Antigen-binding IgE cross-links FceRI on mast cells involves the generation and activation of PKCδ, ERK, tyrosine kinases (Syk and Lyn) and mitogen-activated protein kinases (MAPKs), inducing the release of chemical mediators which provoke inflammation and hypersensitive reaction. Other stimuli, including, cytokines, neuropeptides, chemical and physical activators, can also act on MCs to release a plethora of inflammatory compounds. Activated MCs produce a broad spectrum of inflammatory cytokines, chemokines, lipid compounds and vasoactive amines, all involved in immune response. By producing TNF, MCs have an antibacterial defense and a protective function; while pathogenic bacteria and their products, such as LPS, have an inflammatory response through MC activation. LPS binding TLR4 produce MC generation IL-1 family members, and chemokines, which may recruit inflammatory cells at the infection site; whereas in KitW/W-v mice, where MCs are genetically absent, the inflammatory effect is not present. We report for the first time a link between MCs and bacteria emphasizing the mediation of inflammatory cytokines/chemokines. We can conclude that mast cells fight bacteria, and their immune response is perfectly integrated in the immune network. We hope that the understanding of microbial and mast cell interaction leads to more efficient therapeutic development in relation to microbial resistance.

Diabetes is a metabolic disorder characterized by hyperglycemia and associated with microvascular and macrovascular syndromes mediated by mast cells. Mast cells are activated through cross-linking of their surface high affinity receptors for IgE (FcRI) or other antigens, leading to degranulation and release of stored inflammatory mediators, and cytokines/chemokines without degranulation. Mast cells are implicated in innate and acquired immunity, inflammation and metabolic disorders such as diabetes. Histamine and tryptase genes in mast cells are overexpressed in pancreatic tissue of type 2 diabetes mellitus (T2DM) patients. Histamine is a classic inflammatory mediator generated by activated receptors of mast cells from the histamine-forming enzyme histidine decarboxylase (HDC), which can be activated by two inflammatory chemokines, RANTES and MPC1, when injected intramuscularly or intradermally in mice. This activation is inhibited in genetically mast cell-deficient W/Wv mice, which show higher insulin sensitivity and glucose tolerance. This study contributes to understanding the mechanism by which mast cells profoundly affect diabetes, and their manipulation could represent a new therapeutic strategy. However, further studies are needed to clarify the role of mast cells in inflammation and metabolic disorders such as diabetes.

Inflammatory diseases represent one of the major causes of morbidity and mortality throughout the world and they affect the functions of several tissues. The pathophysiology of these diseases involves release of many pro-inflammatory mediators such as cytokines/chemokines, histamine, C3a, C5a (complement components), bradykinin, leukotrienes (LTC4, LTD4, LTE4), PAF, and substance P, in addition to anti-inflammatory molecules. Recently, it has been demonstrated that neuroimmune interactions are important in the initiation and progress of inflammatory processes. Substance P is an 11-amino acid neuropeptide that is released from nerve endings in many tissues. It acts via membrane-bound NK1 receptors (NK1R). Inflammatory and neuropeptides such as substance P stimulate the release of chemokines, in particular IL-8, a potent neutrophil chemoattractant. Expression of IL-8 is regulated mainly by the transcription factors NF-kappaB, activating protein-1. Substance P plays an important role in immunological and inflammatory states, and it is a mediator of tissue injury, asthma, arthritis, allergy and autoimmune diseases. In this article, our studies revisited the interrelationship between these two powerful inflammatory compounds: substance P and cytokines. These observations suggest that these inflammatory molecules may represent a potential therapeutic target to treat several inflammatory states.

The mechanism of anterior cruciate ligament (ACL) injury is still unclear. To gain this insight, knowledge of the mechanical behaviour of the healthy ACL during activities that may stress the ligament must be investigated in vivo. The goal of this research was to measure ACL strain in vivo during rapid deceleration, a sport type movement that has been previously shown to precede injuries to the ACL in healthy subjects. A young male subject with no previous knee joint injuries volunteered after informed consent. The strain gauge device (DVRT) was calibrated and surgically implanted in the antero-medial band of the intact ACL. The subject was then transported to the lab for data collection. The zero strain position of the ACL was determined using the slack-taut technique. The subject hopped as quickly as possible from a distance of 1.5 m to the target, an X taped at the centre of a force plate, landing with the instrumented left leg and stopping in the landed position. The entire collection window was five seconds at 1000 Hz. A total of three rapid deceleration trials were collected and averaged over the hop cycle. The slack-taut test was then repeated to ensure proper operation of the DVRT and the reliability of the results. The results showed an average peak strain of the ACL during the instrumented Lachman test of 2.00+/-0.17%. The average peak strain of the ACL during the rapid deceleration task was 5.47+/-0.28%. The data indicate that the RD task caused an increase in peak ACL strain that is much higher than during the instrumented Lachman test, and that the strain begins to increase during the flight phase, prior to landing, and reaches a peak that corresponds to the peak ground reaction force. This technique may be used in further sport-specific movements to gain insight into movement patterns associated with ACL injury mechanisms.

Atherosclerosis is an inflammatory disease and hyperlipidaemia is one of the main risk factors for aging, hypertension and diabetes. Variance in plasma LDL cholesterol concentration may be associated with differences in cardiovascular disease risk and high levels of lipids are associated with increased risk of developing atherosclerosis. Macrophages, which generate pro-inflammatory cytokines, mainly interleukin-1 (IL-1) and tumor necrosis factor-α (TNF-alpha), are deeply involved in atherosclerosis, as well as mast cells which generate several cytokines, including IL-6 and IFN-gamma, and chemokines such as eotaxin, MCP-1 and RANTES involved in monocyte recruitment and differentiation in the arterial wall. In addition, mast cells participate in lipid retention and vascular cell remodeling, and are mediators of innate and adaptive immunity during atherosclerosis. Mast cells which accumulate in the human arterial intima and adventitia during atherosclerotic plaque progression, release vasoactive and angiogenic compounds, and pro-inflammatory mediators, such as arachidonic acid metabolites, histamine, cytokines/chemokines, platelet activating factor (PAF) and proteolytic enzymes. Mast cells can be activated by pro-inflammatory stimuli, including cytokines, hypercholesterolemia, and hyperglycemia, and trigger the endothelial expression of adhesion molecules such as P-selectin, vascular cell adhesion molecule-1 (VCAM-1) and chemokines which mediate the recruitment and adhesion of leukocytes. The participation of mast cells in atherosclerosis is still an enigma and it may be of therapeutic interest to clarify this process.

Inflammation, neurodegeneration, imbalance of neurotransmitter systems, oxidative stress and depression are all risk factors for obesity. There is evidence regarding the cross-talk between adipose tissue and the immune system and obese patients may show an alteration of immune functions with major depression, including immune suppression with reduced T-cell and macrophage activity. Obesity is mediated by inflammatory cells such as lymphocytes, macrophages and mast cells which release pro-inflammatory cytokines and chemokines. Obesity-induced leukocyte infiltrations in adipose tissue cause cytokine/chemokine release and inflammation. Here, we report the relationship between obesity, neurological alterations and inflammation.

Microglia derive from mononuclear myeloid progenitors and are a major glial complement of the central nervous system. When microglia are activated they secrete inflammatory cytokines and toxic mediators which amplify the inflammatory response. In addition, the microglia inflammatory products are implicated in the neuronal destruction usually observed in various neurodegenerative diseases. Microglia cells express corticotropin releasing hormone (CRH) receptors, and activation of microglia by CRH releases bioactive molecules which have a biological effect in the brain and regulate several neurological diseases. CRH plays a pivotal role in stress responses and is a key mediator of the hypothalamic-pituitary-adrenocortical system. CRH is expressed in human mast cells, leading to autocrine effects and participates in inflammatory response together with neuropeptides, and stimulates mast cells. IL-33-activated mast cells release vascular endothelial growth factor in response to CRH and act synergistically to increase vascular permeability. CRH also up-regulates IL-18 expression by increasing intracellular reactive oxygen in microglia cells. Here we report the relationship between CRH, microglia and mental disorders.

Mast cells are inflammatory cells, and they are prominent in inflammatory diseases such as allergy and asthma. Mast cells possess high-affinity receptors for IgE (FcERI) and the cross-linking of these receptors is essential to trigger the secretion of granules containing arachidonic acid metabolism (such as prostaglandin (PG) D2, leukotriene (LT) B4, and LTC4), histamine, cytokines, chemokines, and proteases, including mast cell-specific chymases and tryptases. Activation of mast cells provokes the secretion of cytokines and mediators that are responsible for the pathologic reaction of immediate hypersensitivity. Sensory nerve stimulation by irritants and other inflammatory mediators provokes the release of neuropeptides, causing an increase in vascular permeability, plasma extravasation and edema. Trigeminal nerve stimulation actives dura mast cells and increases vascular permeability, effects inhibited by capsaicin. Capsaicin causes release of sensory neuropeptide, catecholamines and vasodilation. Several studies have reported that capsaicin is effective in relief and prevention of migraine headaches, improves digestion, helps to prevent heart disease, and lowers blood cholesterol and blood pressure levels. The findings reported in these studies may have implications for the pathophysiology and possible therapy of neuroinflammatory disorders.

Vascular endothelial growth factor (VEGF) is one of the most important inducers of angiogenesis, therefore blocking angiogenesis has led to great promise in the treatment of various cancers and inflammatory diseases. VEGF, expressed in response to soluble mediators such as cytokines and growth factors, is important in the physiological development of blood vessels as well as development of vessels in tumors. In cancer patients VEGF levels are increased, and the expression of VEGF is associated with poor prognosis in diseases. VEGF is a mediator of angiogenesis and inflammation which are closely integrated processes in a number of physiological and pathological conditions including obesity, psoriasis, autoimmune diseases and tumor. Mast cells can be activated by anti-IgE to release potent mediators of inflammation and can also respond to bacterial or viral antigens, cytokines, growth factors and hormones, leading to differential release of distinct mediators without degranulation. Substance P strongly induces VEGF in mast cells, and IL-33 contributes to the stimulation and release of VEGF in human mast cells in a dose-dependent manner and acts synergistically in combination with Substance P. Here we report a strong link between VEGF and mast cells and we depict their role in inflammation and immunity.

Mast cells in the tissue are located close to nerves in and around the small vessels where they orchestrate important immune response after antigen recognition through Toll-like receptors. Mast cells can activate T and B lymphocytes and dendritic cells and have been postulated to act directly within tissue allografts and/or to induce indirect effects via inflammatory mediator release, therefore they have been shown to play an indispensable role in allograft tolerance. Major limitation in the success of transplantation is the immune response of the recipient to the donor tissue. The failure of tissue grafting is caused by an inflammatory reaction called rejection. Mast cells play a role during immune response and are elicited with transplanted allograft and also may exhibit their immune-regulatory effects directly through secretion of modulatory cytokines and activation of metabolic pathways. However, the role of mast cells in transplantation is poorly understood. The most severe rejection episodes have been found in patients with an increased number of mast cells. Mast cell mediators which can activate latent forms of TGF-β or increase angiotensin II levels are capable of inducing fibrosis through various mechanisms, activating fibroblasts and inducing collagen synthesis. Mast cells are also implicated in regulatory T-cell functions and are required to sustain peripheral tolerance via Treg, therefore there is an interaction between mast cells and Treg cells. Treg create IL-9 in enhancing mast cell growth and Chemotaxis, suggesting that Treg and mast cells form a functional unit that mediates graft tolerance. In this study we concentrate our attention on the role of mast cells in rejection of allografts and try to understand the role of mast cell-related immune mechanisms in organ transplantation.

Atherosclerosis is an inflammatory disease due to a diet high in saturated fat, hypercholesterolemia, obesity, hypoglycemia, etc. mainly mediated by the infiltration of macrophage and T cells into the vascular wall. Once the endothelial is damaged monocytes penetrate the tissue and are transformed in scavenger cells. Upon stimulation of Th1 cells, a group of cytokines is released and contributes to the inflammatory response of atherosclerotic tissue. When macrophages proliferate they amplify inflammatory response through the secretion of growth factors and cytokines such as TNF and IL-1. In addition, chemokines such as RANTES and other C-C chemokines are generated, and matrix metalloprotinease 9 (MMP-9) are produced by activated monocytes. However, the immune system in atherosclerosis still remains unclear. Here, in this study we revisited the inter-relationship between atherosclerosis and inflammation.

Mast cells, which derive from a bone marrow progenitor and mature in tissues, are important for allergic reactions, but also in inflammation, autoimmunity, and T-cell-mediated immune responses. The addition of certain cytokines to human umbilical cord blood-derived cultured mast cells have been shown to augment IgE-induced production of distinct cytokines, without histamine secretion. CCL2/MCP-1 is a beta chemokine capable of attracting and activating lymphocytes, macrophages, memory T cells and basophilic cells, but not neutrophils. CCL2/MCP-1 regulates the recruitment of inflammatory cells into tissue during inflammation and allergy. IL-33 belongs to the IL-1 family and binds to the ST2 receptor which has high homology to IL-1 receptor and has biological activities. IL-33, causes allergic inflammation and exerts significant biological effects both in vivo and in vitro. IL-33 induces expression of several cytokines and chemokines, resulting in severe inflammatory and allergic diseases. However, our knowledge regarding the effects of these cytokines on human mast cell functions is limited. Here, using human umbilical cord blood mast cells (HUCBMCs) as a valid model, we found that IL-33 induces CCL2/MCP-1 release in HUCBMCs. The release was higher at 24 h incubation compared with 12 h. This study documents the ability of IL-33 to directly stimulate Human umbilical cord blood mast cells (UCBMCs) to produce CCL2/MCP-1. We show that IL-33 is a strong activator of human mast cells capable of inducing CCL2/MCP-1 released at translational level. The present data describe an additional biological activity of IL-33, suggesting that this cytokine may have an important effect on the recruitment of inflammatory cells in allergic diseases. Copyright © by BIOLIFE, s.a.s.

Immunological and biochemical reactions associated with inflammation are elicited in response to a physical or immunological challenge. Early in inflammation there is mobilization and infiltration of neutrophils, mast cells and macrophages to the site of inflammation. These cells release pro-inflammatory compounds icluding cytokines, vasoactive peptides (eg., histamine), and eicosanoids. The release of prostaglandin D2 (PGD2) and tryptase induced by anti-IgE, A23187 and compound 48/80 were studied using in vitro a good and valid model of human cord blood-derived mast cells (HCBDMC). Tryptase is a mast cell product and enhances vasopermeability with anticoagulant activities. In this study we measure the release of PGD2 and tryptase on mast cells activate by anti-IgE, calcium ionophore A23187, polybasic compound 48/80 (an agent containing a cationic region adjacent to a hydrophobic moiety, which works by activating G proteins) and IL-18. The generation of PGD2 was measured by radioimmunoassay. Release of PGD2 was detectable (after 12 h) following challenge with anti-IgE, A23187 and compound 48/80. Our data show that mature HCBDMC produce proinflammatory PGD2 following triggering with anti-IgE and with IgE-independent agonists, such as calcium ionophore A23187 and polybasic compound 48/80, while IL-18 was unable to stimulate the release of PGD2 or tryptase on HCBDMC. Although a great deal has been learned about the mediators produced by mast cells, the ultimate biologic function(s) of mast cells remains a mystery.

This review examines recent articles on the relationship of cytokines to allergy and inflammation with particular emphasis on interleukin (IL)-4. The objective of this article is therefore to review published studies to identify cytokines consistently involved in allergic inflammation. Proinflammatory cytokines, including IL-4, IL-5, IL-13 and GM-CSF along with TNF-alpha play a role in allergen-induced airway leukocyte recruitment and these cytokines can be generated by T mast cells and other cells. In addition, IL-9, IL-25, IL-33, IL-17, IL-27 and IFN-γ are deeply involved in the regulation of asthma. Blocking the effect of these proinflammatory cytokines might provide new therapeutic approaches for the control of allergy and inflammation.

The acute phase response is the part of the innate defence system of an animal against trauma, inflammation or infection. During this response, there is increased production and release of certain plasma proteins known as acute phase proteins, which include C-reactive protein (CRP), serum amyloid A (SAA) and fibrinogen (Fg). CRP consists of five identical subunits of 206 amino acids with a molecular weight of approximately 23 kDa. There is strong evidence from numerous studies that CRP is a predictor of inflammation. The acute-phase protein serum amyloid A (SAA) is a clinically useful marker of inflammation. SAA plays not only an important role in the development of AA amyloidosis (an important complication of rheumatoid arthritis) but also interacts with events closely involved in the metabolic syndrome as a high- and low-grade inflammatory modulator. Fibrinogen (Fg) is a high molecular weight plasma adhesion protein and is a biomarker of inflammation. It is synthesized and assembled in hepatocytes and fibroblasts and when secreted into the circulation, its plasma half-life ranges from 3 to 4 days. Several cytokines, are involved in the induction of acute phase protein synthesis, but the mutual importance of these cytokines seems to be cell-type specific and to vary in various experimental settings. Here we revisited the classic acute phase proteins SAA, C-Reactive protein and fibrinogen in their role in inflammation and their interrelationship with some cytokines.

Obesity is one of the main rising causes of health problems in modern society and is correlated to type 2 diabetes mellitus, hypertension, heart disease and atherosclerosis. Bacterial products, endogenous substances such as oxidized LDL (ox-LDL) and heat shock proteins mediate activation of Toll-like receptors and reinforce the view that the innate immune system plays a key role in the genesis of atherosclerosis. In addition, natural killer T (NKT) cells respond to lipids presented via CD1d on APCs, and may also be able to affect atherosclerosis. All the main cell types involved in atherosclerosis such as endothelial cells, macrophages, T cells, smooth muscle cells and platelets express proinfammatory cytokines. In addition, CD4 ligation triggers the expression of adhesion molecules, cytokines and matrix metalloprotinease. IL-6 cytokines travels to the liver where it elicits acute phase response resolving in the release of serum amyloid-A C-reactive protein, fbrogen and plasminogen activator inhibitor-1. Therefore increasing body fat mass is associated with high levels of infammatory cytokines such as IL-1 and TNF. In this study we revisit the interrelationship between fat and infammation.

As in Northern Germany there have recently been several deaths caused by Escherichia coli (E.coli), we decided to revisit the effects of E.coli infection. Since this bacteria is the most numerous facultative and aerobic germ in the human intestine, we would like to warn the population of its pathogenicity. In fact, E.coli can be pathogenic both in humans and in animals and can start an inflammatory process, activating some factors of the cell nucleus such as NFkB, with the consequent production of cytokines. E.coli can appear in several strains and can be very aggressive and can contaminate food, water and the environment, causing severe disease, and in some cases death.

Cytokines are immunal regulatory proteins, however they also play a relevant role in inflammatory diseases. IL-31 is a newly discovered cytokine expressed primarily in TH2 cells, introduced by activated CD4+ T cells. IL-31 is capable of inducing chemokines and other cytokines in several inflammatory diseases via its surface receptor. This cytokine is also produced by mast cells and mast cell line, suggesting a role in allergic diseases. In this editorial we revisit the biological role of IL-31 in immunity and inflammation.

The inflammatory response is mediated by immunological and chemotactic factors, proteins of the complement system, histamine, serotonin, arachidonic acid products and cytokines. All these compounds, including cytokines/chemokines, are major contributors to the symptoms of inflammation. Cytokines/chemokines, commonly referred to as “biological response modifiers”, are relatively new compounds for possible use in stimulation of the immune response, and display a number of overlapping abilities to stimulate cells of various lineages and differentiation stages; nonetheless, most of these compounds are potent inflammatory mediators. Mast cell mediators are either contained within secretory granules or can be synthesized de novo and can be released upon activation by either a massive degranulation, or by a selective release of specific molecules. These cells accumulate in the stroma of a variety of inflamed and transformed tissues in response to locally produced chemotactic factors for immune-cells, such as RANTES and MCP-1. Here we describe some connections between mast cells and chemokines.

IL-32 is onae of the last important cytokines discovered, produced mainly by T cells, natural killer cells, and epithelial cells. Probably many other different cells are a source of IL-32, which has been found to be a powerful pro-inflammatory mediator. Here we studied the effect of IL-32 on histamine release by human-derived cord-blood mast cells. In these studies we found that IL-32 significantly stimulates the release of histamine only at high concentrations (100 ng/ml) while at 10 or 50 ng/ml it had no effect. These results were found for the first time and demonstrate that IL-32 may play an important role in allergic and inflammatory diseases. Copyright © by BIOLIFE, s.a.s.

Autism spectrum disorder is of interest neurochemically because it represents a relatively homogeneous disorder with regard to disease development, abnormal cognitive development and intellectual development disturbance. A consistent finding in autistic children is a high number of mast cells and a high level of serotonin which is also found at elevated concentrations in the urine of autistic patients. In addition, a dysfunction of clinical conditions, such as gastrointestinal and immunological symptoms, is frequently noted in autistic children, however, IgE does not appear to be prevalent in these children but probably an increase of cytokines/chemokines produced by mast cells at an early age may play an important role. Therefore an immune hypothesis, involving also autoimmunity, is one possible pathogenetic mechanism in autism. In conclusion, mast cell activation could contribute to immune and neuroinflammatory abnormalities that are evident in patients with autism spectrum disorders.

The tridecapeptide neurotensin (NT) acts in the mammalian brain as a primary neurotransmitter or neuromodulator of classical neurotransmitters. Morphological and functional in vitro and in vivo studies have demonstrated the existence of close interactions between NT and dopamine both in limbic and in striatal brain regions. Additionally, biochemical and neurochemical evidence indicates that in these brain regions NT also plays a crucial role in the regulation of the aminoacidergic signalling. Immune cells, such as lymphocytes, macrophages and mast cells are reported to be activated by neuropeptides, such as neurotensin; this activation leads to cytokine and immunoglobulin production. In addition, neurotensin increases calcium level and the production of nitric oxide, therefore neurotensin is deeply involved in immunity and inflammation but its real function still remains to be elucidated.

The activation of monocytes/macrophages by several stimuli is an initial event in the inflammatory response. To ascertain the importance of LTB(4) and 5-lypoxigenase in the inflammatory site, we isolated and stimulated rat adherent granuloma macrophages (RAGMs) with calcium ionophore in the presence or absence of regulated on activation, normal T expressed and secreted (RANTES) [CCL5] at different concentrations. We tested the hypothesis that RANTES may influence the production of LTB(4) stimulated by calcium ionophore A23187 (2.5 microM/ml) in rat adherent granuloma macrophages derived from granuloma induced by potassium permanganate diluted 1:40 saturated solution. To test this hypothesis, we measured LTB(4) production, in rat granuloma macrophages stimulated with A23187 (2.5 microM) alone and in combination with RANTES at different concentrations. In these studies, the cell-free supernatant of stimulated RAGMs with the ionophore A23187, resulted in a drastic increase of LTB(4). However, when the cells were treated with the combination RANTES plus A23187 the stimulatory effect was more pronounced than A23187 alone. LTB(4) production was quantitated. The calcium ionophore A23187 directly induced LTB(4) in macrophages, this production was markedly enhanced when the cells were pretreated with RANTES. However, the addition of RANTES in the absence of calcium ionophore A23187 did not directly induce LTB(4) release, nor was lypoxigenase expression augmented. Preincubation of RAGMs with NDGA (nordihydroguiaretic acid) (10(-5)M) completely abolished the production of LTB4 on RAGMSs challenged with A23187 in combination with RANTES or A23187 alone in the supernatants. Similar effects were obtained when the cells were pretreated with dexamethasone. These data suggest, for the first time, that RANTES may stimulate the release of LTB(4), only when it is associated to other stimuli and for this reason we conclude that RANTES modulates inflammatory diseases, and may require other stimuli to be effective in amplifying its spectrum of action(s).

Purpose: Mast cells play an important role in innate and acquired immunity and are thought to be the cellular origin of most proteases and cytokines. Substance P (SP) and its receptor, NK-1R, play critical roles in immune regulation in human and animal models of inflammation. Methods: We used mature human cord blood mast cells (HCBMC) differentiated from cord blood CD34+ precursor activated with SP in culture. Results: Our data indicate that Substance P strongly activates mature HCBMC in releasing CXCL8 expression and secretion (Control: 1.200 ± 1.0; SP: 4.10 ± 0.90; P < 0.01). Moreover, in a RT-PCR, HCBMC expressed CXCL8 mRNA after Substance P activation. Since calcium ionophore A23187 is a pharmacological activator that raises cytosolic free calcium ion concentraion and stimulates mast cells in the production and secretion of proinflammatory compounds, it was used as positive control. In addition, we found that HCBMCs generate the transcription of histidine decarboxylase (HDC), the enzyme responsible for the generation of histamine from histidine, after SP treatment. Since CXCL8 is a member of the CXC chemokine subfamily with potent chemotactic activity and is a primary inflammatory cytokine we conclude that our results, obtained from HCBMC cultures, a good and valid model in vitro, support the concept that the neurogenic system modulates inflammatory events by Substance P-mediated HCBMC chemokine CXCL8 release. Conclusion: The expression, synthesis and release of CXCL8 suggest an increase of inflammatory process in vivo mediated by the recruitment and infiltration of inflammatory cells in inflamed tissues.

Cytokines are immunomodulatory and inflammatory compounds produced by many different cell types. The IL-1 family consists of at least eleven cytokines including IL-18 and IL-13 and are essential to the host defence against severe infections and mediate inflammation. IL-18 also enhances tumour rejection and has high capacity to augment the cytotoxicity of NK cells and T cells. IL-33 stimulates basophils and mast cells to produce cytokines and histamine independently of IgE. Mast cells play a crucial role in the development of allergy through the cross-linking of their surface receptors for IgE leading to degranulation and inflammation. Activated mast cells induce the generation of PGD2, detectable in 2–15 minutes after challenge, and LTC4. Here we review the interrelationship between PGD2, IL-1 family members and mast cells.

Mast cells reside in connective tissues and are widely recognized as effector cells important in innate and acquired immunity. These cells are the only ones capable of storing preformed TNFα in their cytoplasmatic granules and release upon activation. TNF-alpha is a potent multifunctional cytokine involved in autoimmune diseases, cancer, allergy, and acute and chronic inflammation. In this study, we revisit the interrelationship between TNFα and mast cells.

Mast cells (MCs) derive from a distinct precursor in the bone marrow and are predominantly found in tissues at the interface between the host and the external environment where they can secrete mediators without overt degranulation. Mast cells mature under local tissue microenvironmental factors and are necessary for the development of allergic reactions, through crosslinking of their surface receptors for IgE (FcεRI), leading to degranulation and the release of vasoactive, pro-inflammatory and nociceptive mediators that include histamine, pro-inflammatory and anti-inflammatory cytokines and proteolytic enzymes. Multiple sclerosis (MS) is an autoimmune disease characterized by inflammatory demylination within the central nervous system. MCs are involved in the pathogenesis of MS by generating various vasoactive mediators and cytokines and participate in the destruction of the myelin sheath and the neuronal cells. The process of the development of demyelinating plaques in MS is probably linked with the rupture of the blood-brain barrier by MC products. The effects of natalizumab, which is a very effective drug in reducing the annualized relapse rate and other relapse-based endpoints, are discussed. Here, we report the relationship between MCs and MS.

In this study we investigated the in vitro behaviour, morphostructure and extracellular matrix synthesis of human dental follicular stem cells (hDFSCs) isolated from human dental bud, which resulted to be positive for mesenchymal markers (CD29, CD90, CD146 and CD166) by FACS analysis. Cells were analysed by light and electronic microscopy to evaluate their biological response either at week 1, that is before differentiation, or at weeks 3–6, when they had been cultured in osteogenic medium onto a highly porous natural scaffold material (Bio-Oss®). Microscopy analysis of primary culture cells showed they had a mesenchymal stem cell-like morphostructure, spindle shaped, similar to the culture of mesenchymal stem cells derived from adult bone marrow. Also, after osteogenic differentiation, these analyses indicate typical osteoblast morphostructure and reveale a tri-dimensional organization of the cells and deposition of extracellular matrix (ECM) in close contact with biomaterial. This approach would allow to personalize the scaffold for bone tissue engineering in order to accelerate the process of osteogenesis.

Cancer cells invade surrounding tissues and metastasize to distant sites. Diet high in fat is a strong link to, and perhaps causes, a high incidence of tumours. Trans-fatty acid might impair the function and it could be involved in the development of cancer. Cholesterol is also strongly suspected to be involved in the development of tumours, therefore it is important for everyone to eat well, especially for people with cancer to prevent the body tissues from breaking down and helping to rebuild the normal tissue that may have been affected by the treatments. Factors secreted by adipocytes and macrophages such as TNF-alpha and other inflammatory proteins are involved in inflammation in cancer. In addition, MCSF which up-regulates adipocyte tissue is also important for the stimulation of fat cell proliferation and is expressed by human adipocytes. Many cytokines, such as IL-1, IL-6, IL-8, IL-32, IL-33 and MCP-1, are biomarkers for cancer and chronic diseases along with transcription factors NFkB and AP-1; these last two factors are important bioactive substances on the molecular mechanism of the control of genes which in turn affect cellular metabolism. In this paper we revisit the interrelationship between cancer and metabolism.

A high level of cholesterol is associated with obesity, cardiovascular diseases and atherosclerosis. Immune response in atherosclerosis is mediated by chemokines which attract monocytes, leading to the innate immune response characterised by the production of cytokines. The immunoregulatory cytokines are an important bridge between innate and adductive immunity. TH1 cytokines are involved as effector T cells in inflammatory response, while TH2 cytokines can be anti-inflammatory such as IL-10 and IL-4. It is well known that statins enhance the production of TH2 cytokines whereas the secretion of TH1 cytokines is suppressed. For this purpose, we studied the significance of anti-inflammatory effect and suppression of inflammation by statins. In this paper we revisited the role of cholesterol and cytokines IL-18, IL-10, IL-12, TNF-α, interferon-γ, and chemokines in inflammatory diseases.

Cytokines such as interleukins, chemokines and interferons are immunomodulating and inflammatory agents, characterized by considerable redundancy, in that many cytokines appear to share similar functions. Virtually all nucleated cells, but especially epithelial cells and macrophages, are potent producers of cytokines. The objective of this study is to review the detailed mechanism of action and the biological profiles of IL-37, the newest anti-inflammatory cytokine. This review focuses on IL-37, a key cytokine in regulating inflammatory responses, mainly by inhibiting the expression, production and function of proinflammatory cytokines: IL-1 family pro-inflammatory effects are markedly suppressed by IL-37.