Mast cells and stress--a psychoneuroimmunological perspective

The effects of alpha-lipoic acid (ALA) on the urinary bladder injury in rats exposed to chronic stress: A histochemical study

Objective: In the present study, we aimed to investigate the morphological and biochemical effects of alpha-lipoic acid (ALA) on bladder injury caused by water avoidance stress (WAS) and to show its effect on the number of degranulated mast cells, which increase after stress. Materials and Methods: Wistar albino rats were subjected to WAS and the animals in the treatment group were injected ALA. After the urinary bladder tissues were subjected to routine tissue processing, hematoxylin-eosin staining and periodic acid-Schiff reaction were applied to observe general morphology and acidic toluidine blue method to investigate mast cells. Biochemical assessments of malondialdehyde (MDA) and glutathione (GSH) were also obtained. Transmission electron microscope was used for the ultrastructural, and scanning electron microscope for the topographical analyses. Results: The experiments showed that chronic stress caused injury in the bladder, increased degranulated and total number of mast cells and decreased GSH and increased MDA levels. ALA treatment after WAS ameliorated bladder injury in most areas, decreased degranulated and total mast cell number and increased GSH and decreased MDA levels. Conclusion: It was concluded that ALA can be a useful agent in the treatment of interstitial cystitis.

Skin and Psychosomatics - Psychodermatology today

Modern psychodermatology relies on the bio-psycho-social disease model in psychosomatics, according to which biological, psychological and social factors (on various levels, from molecules to the biosphere) play a major role in the disease pathogenesis through complex, non-linear interactions over the entire disease course. It is nowadays experimentally proven that "emotions get into the skin". Recent research shows close anatomical, physiological and functional connections between skin and nervous system, already known to be ontogenetically related. These connections are reflected in many skin diseases where psychological and somatic etiological factors are closely intertwined. A holistic approach by the physician should do justice to this interdependence; biological, psychological and social factors should be adequately taken into account when taking anamnesis, making a diagnosis and choosing a therapy. The "visibility" of the skin organ bestows dermatology a special position among the various other clinical subjects, and renders a holistic, psychosomatic approach to the patient that is particularly important. The life course belongs also to modern psychodermatological approaches. Based on the modern psychodermatology concept, other corresponding sub-areas such as psychogastroenterology, psychocardiology etc. have emerged. After the theoretical part of this article, some selected skin diseases are discussed in more detail from the psychosomatic point of view.

Migraine associated with gastrointestinal disorders: A pathophysiological explanation

BACKGROUND

Migraine is a highly prevalent, disabling, and costly disorder worldwide. From a long time ago, headaches have been known to be associated with gastrointestinal (GI) disorders. Headaches originating from gastric complaints were appreciated by Persian Medicine (PM) scholars. Today, functional GI disorders are shown to have high comorbidity with migraines; however, a causal relationship is not accepted today and pathophysiological explanations for this comorbidity are scarce. Therefore, based on the PM philosophy and the existing evidence, we aimed to propose an explanation for the co-morbidity of migraine and GI disorders.

SUMMARY

Noxious stimuli from the GI tract are relayed to the nucleus tractus solitarius (NTS) in the brain stem, which is located close to the trigeminal nucleus caudalis (TNC). TNC has shown projections to (NTS) through which frequent GI stimuli may antidromically reach the TNC and finally result in neurogenic inflammation. In addition, immune products, particularly histamine, are released in the submucosa of the GI tract and absorbed into the systemic circulation, which renders migraineurs more prone to attacks.

The role of stress in the mosaic of autoimmunity: An overlooked association

Stress is defined as the pscyophysiological reaction in which the steady state is disturbed or threatened. Stress is not always perceived as a negative response. Stress results when environmental demands exceed an individuals' adaptive capacities. Autoimmune diseases are heterogeneous group of chronic diseases which occur secondary to loss of self antigen tolerance. The etiopathogenesis of autoimmune disease is uncertain. Genetic factors as well as environmental factors appear to interplay, leading to a cascade of events resulting in disease onset. Stress has been postulated to play a role in disease onset in the genetically susceptible patients. During the stress response, catecholamines and glucocorticoids are released from locus coeruleus and adrenal gland. These biomolecules exert control over various immune cells in the innate and adaptive arms of the immune system, thereby altering the cytokine profile released. The increase of IL-4 promotes T-helper 2 (T_h2) cell differentiation, while the decrease in IL-12 and the increased IL-10 production reduce the number of T-helper 1 (T_h1) cells. The relationship between stress and autoimmune diseases is intricate. Stress has been shown to be associated with disease onset, and disease exacerbations in rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease, multiple sclerosis, Graves' disease as well as other autoimmune conditions. In certain conditions such as psoriasis, stress has been implicated in delaying lesion clearance upon the application of standard treatment regimes. Finally, psychological therapy and cognitive behavioral therapy aimed to reduce stress levels was shown to be effective in influencing better outcomes in many autoimmune diseases. The purpose of this paper is to closer inspect the clinical evidence regarding the role of stress on influencing the various aspects of disease entities.

Rat Basophilic Leukemia Cells (RBL-2H3) Generate Prostaglandin D2 (PGD2) after Regulated upon Activation, Normal T-cell Expressed and Secreted (RANTES) activation

Increasing evidence indicates that local neurogenic inflammation, possibly in response to different stimuli, may be involved in sensory nerve sensitization, migraine generation and some other precipitating events leading to neuronal dysfunction in the brain. In addition, mast cells generate eicosanoids that are linked to asthma and other inflammatory diseases. Regulated upon activation, normal T-cell expressed and secreted (RANTES) is a small protein and a prototype member of the CC chemokine-beta subfamily with chemoattractant and inflammatory properties. In this study we used the RBL-2H3 cell line to determine whether or not these cells generate prostaglandin D2 (PGD2) after treatment with RANTES. After 4 hours of incubation, RBL-2H3 cells cultured with RANTES at 20 ng/mL released large amounts of PGD2 in a dose-response manner compared to control. Moreover, RBL-treated RANTES generated a large quantity of histamine. Our study confirms once again the proinflammatory action of RANTES, in this case acting on the stimulation of the arachidonic acid cascade product PGD2.

Mast cells' involvement in inflammation pathways linked to depression: evidence in mastocytosis

Converging sources of evidence point to a role for inflammation in the development of depression, fatigue and cognitive dysfunction. More precisely, the tryptophan (TRP) catabolism is thought to play a major role in inflammation-induced depression. Mastocytosis is a rare disease in which chronic symptoms, including depression, are related to mast cell accumulation and activation. Our objectives were to study the correlations between neuropsychiatric features and the TRP catabolism pathway in mastocytosis in order to demonstrate mast cells' potential involvement in inflammation-induced depression. Fifty-four patients with mastocytosis and a mean age of 50.1 years were enrolled in the study and compared healthy age-matched controls. Depression and stress were evaluated with the Beck Depression Inventory revised and the Perceived Stress Scale. All patients had measurements of TRP, serotonin (5-HT), kynurenine (KYN), indoleamine 2,3-dioxygenase 1 (IDO1) activity (ratio KYN/TRP), kynurenic acid (KA) and quinolinic acid (QA). Patients displayed significantly lower levels of TRP and 5-HT without hypoalbuminemia or malabsorption, higher IDO1 activity, and higher levels of KA and QA, with an imbalance towards the latter. High perceived stress and high depression scores were associated with low TRP and high IDO1 activity. In conclusion, TRP metabolism is altered in mastocytosis and correlates with perceived stress and depression, demonstrating mast cells' involvement in inflammation pathways linked to depression.

Mastocytosis in adulthood and neuropsychiatric disorders

Patients with mastocytosis can display various disabling general and neuropsychological symptoms among one third of them, including general signs such as fatigue and musculoskeletal pain, which can have a major impact on quality of life. Neurological symptoms are less frequent and mainly consist of acute or chronic headache (35%), rarely syncopes (5%), acute onset back pain (4%), and in a few cases, clinical and radiological symptoms resembling or allowing the diagnosis of multiple sclerosis (1.3%). Headaches are associated with symptoms related to mast cell activation syndrome (flushes, prurit, and so forth) and more frequently present as migraine (37.5%), with often aura (66%). Depression-anxiety like symptoms can occur in 40% to 60% of the patients and cognitive impairment is not rare (38.6%). The pathophysiology of these symptoms could be linked to tissular mast cell infiltration or to mast cell mediators release or both. The tryptophan metabolism could be involved in mast cell-induced neuroinflammation through indoleamine-2,3-dioxygenase activation. Treatments targeting mast cell may be useful to target neuropsychological features associated with mastocytosis, including tyrosine kinase inhibitors.

Dietary Supplements for Arthritis and other Inflammatory Conditions: Key Role of Mast Cells and Benefit of Combining Anti-Inflammatory and Proteoglycan Products

Arthritis is estimated to affect over 30% of all adults and all the available drugs add considerable morbidity and mortality of their own. A recent therapeutic approach targets the mast cells that are currently considered critical in a variety of inflammatory diseases, especially arthritis. Mast cells could be activated by many immune and neural triggers, as well as by many food substances and drugs leading to secretion of numerous vasoactive and inflammatory molecules. Recent studies have shown that mast cells can be inhibited by certain naturally occurring flavonoids, such as quercetin, and the sulfated proteoglycan chondroitin sulfate. Glucosamine and chondroitin are present in many dietary supplements, but neither the source nor the purity of the active substances is listed; moreover, these formulations do not permit sufficient absorption, due to the high molecular weight and negative charge. Moreover, a common source of chondroitin sulfate is cow trachea with the risk of spongioform encephalopathy (mad cow disease). A new series of dietary supplements (Algonot-Plus®) are based on published scientific evidence and combine quercetin, glucosamine sulfate and chondroitin sulfate of high purity in formulations that include kernel olive oil to increase absorption of the inhibitory substances.

Vitamin E slows down the progression of osteoarthritis

Osteoarthritis is a chronic degenerative joint disorder with the characteristics of articular cartilage destruction, subchondral bone alterations and synovitis. Clinical signs and symptoms of osteoarthritis include pain, stiffness, restricted motion and crepitus. It is the major cause of joint dysfunction in developed nations and has enormous social and economic consequences. Current treatments focus on symptomatic relief, however, they lack efficacy in controlling the progression of this disease, which is a leading cause of disability. Vitamin E is safe to use and may delay the progression of osteoarthritis by acting on several aspects of the disease. In this review, how vitamin E may promote the maintenance of skeletal muscle and the regulation of nucleic acid metabolism to delay osteoarthritis progression is explored. In addition, how vitamin E may maintain the function of sex organs and the stability of mast cells, thus conferring a greater resistance to the underlying disease process is also discussed. Finally, the protective effect of vitamin E on the subchondral vascular system, which decreases the reactive remodeling in osteoarthritis, is reviewed.

Psychosocial impact of mast cell disorders: Pilot investigation of a rare and understudied disease

Mast cell disorders are rare, chronic diseases involving unpredictable physical symptoms ranging in severity, duration, and frequency. Almost two-thirds of participants with these disorders ( n = 180) experienced clinically meaningful depressive symptoms. Depressed mood was associated with somatic symptomatology, poorer quality of life, lower resilience, and indirectly with ways of coping. Newly developed measures for this population performed psychometrically well. There was no gender difference in depression but women reported greater use of several ways of coping, greater disease-related distress, poorer quality of life, and more symptoms. Results underscore the need for further research and development of effective psychosocial interventions for this population.

Kounis syndrome: an update on epidemiology, pathogenesis, diagnosis and therapeutic management

Kounis syndrome has been established as a hypersensitivity coronary disorder induced by various conditions, drugs, environmental exposures, foods and coronary stents. Allergic, hypersensitivity, anaphylactic and anaphylactoid reactions are associated with this syndrome. Vasospastic allergic angina, allergic myocardial infarction and stent thrombosis with occluding thrombus infiltrated by eosinophils and/or mast cells constitute are the three reported, so far, variants of this syndrome. Apart from coronary arteries, it affects the cerebral and mesenteric arteries. Its manifestations are broadening and its etiology is continuously increasing. Kounis syndrome is a ubiquitous disease which represents a magnificent natural paradigm and nature’s own experiment in a final trigger pathway implicated in cases of coronary artery spasm and plaque rupture. Kounis syndrome seems to be not a rare disease but an infrequently diagnosed clinical entity which has revealed that the same mediators released from the same inflammatory cells are also present and in acute coronary events of non allergic etiology. These cells are not only present in the culprit region before plaque erosion or rupture but they release their contents just before an actual coronary event. Therefore, awareness of etiology, epidemiology, pathogenesis and clinical manifestations seems to be important for its prognosis, diagnosis, treatment, prevention.

Honeycomb-like Structured Film Regulates Mediator Release from Non-Tumor Mast Cells

We previously reported a honeycomb-like structured film (HCF) stimulates mast cell proliferation and multinucleated formation. In this study, we examined the role of HCF in regulating the release of mediators from cultured mast cells. We measured the release of histamine, substance P, tumor necrosis factor (TNF)-α, and leukotriene B4 (LTB-4) from NCL-2 cells (proliferative mouse non-tumor mast cells). After 7 days of culture, HCF selectively down-regulated the release of TNF-α, LTB-4, and (to a lesser extent) substance P, but not histamine. Mast cell attachment to HCF may have a greater effect on release of de novo synthesized molecules.

Brain injury due to anaphylactic shock: broadening manifestations of Kounis syndrome

Anaphylactic shock is a real and life threatening medical emergency which is encountered in every field of medicine. The coronary arteries seem to be the primary target of anaphylaxis resulting in the development of Kounis syndrome. Kounis syndrome is a pan-arterial anaphylaxis -associated syndrome affecting patients of any age, involving numerous and continuously increasing causes, with broadening clinical manifestations and covering a wide spectrum of mast cell activation disorders. Recently, Kounis-like syndrome affecting the cerebral arteries was found to be associated with mast cell activation disorders. In anaphylactic shock, the decrease of cerebral blood flow is more than what would be expected from severe arterial hypotension. This is attributed to the early and direct action of anaphylactic mediators on cerebral vessels. While adrenaline is a life saving agent in the treatment of anaphylactic shock, it contains sodium betabisulfite as preservative and should be avoided in sulfite allergic patients. Potential allergens encountered in endodotic practice include formocresol, zinc compounds thiurams, sodium dimethyldithiocarbamade, and mercaptobenzothiazole that might have synergistic action. All these agents together with analgesics, antibiotics, antiseptics, formaldehyde, latex, local anaesthetics and metals used in dental practice, in general, can induce anaphylactic shock. Practitioners should be aware of these consequences. A careful history of previous atopy and reactions is of paramount importance for safe and effective management.

Kounis syndrome: a new twist on an old disease

Kounis syndrome is the concurrence of acute coronary syndromes with conditions associated with mast cell activation, such as allergies or hypersensitivity and anaphylactic or anaphylactoid insults that can involve other interrelated and interacting inflammatory cells behaving as a 'ball of thread'. It is caused by inflammatory mediators such as neutral proteases including tryptase and chymase, arachidonic acid products, histamine, platelet activating factor and a variety of cytokines and chemokines released during the activation process. Platelets with FCεRI and FCεRII receptors also participate in the above cascade. Vasospastic allergic angina, allergic myocardial infarction and stent thrombosis with occluding thrombus infiltrated by eosinophils and/or mast cells constitute the three reported variants of this syndrome. Kounis syndrome is a ubiquitus disease that represents a magnificent natural paradigm and nature's own experiment, in a final trigger pathway implicated in cases of coronary artery spasm and plaque rupture. Kounis syndrome can complicate anesthesia, vaccination, medical therapy and stent implantation and it seems to be associated with coronary allograft vasculopathy and takotsubo syndrome, it can often be confused with hypersensitivity myocarditis and can be the cause of unexplained sudden death. Kounis syndrome has revealed that the same mediators released from the same inflammatory cells are present in acute coronary events of nonallergic etiology. These cells are not only present in the culprit region before plaque erosion or rupture but they release their contents just before an actual coronary event. Therefore, does Kounis syndrome represent a magnificent natural paradigm and nature's own experiment in a final trigger pathway implicated in cases of coronary artery spasm and plaque rupture showing a novel way towards our effort to prevent acute coronary syndromes? Drugs, substances targeting the stem cell factor that is essential for mast cell development, proliferation, survival, adhesion and homing as well as monoclonal antibodies and natural molecules that protect mast cell surface and stabilize mast cell membrane could emerge as novel therapeutic ways capable to prevent acute coronary and acute cerebrovascular events.

Psychoneuroimmunologic factors in inflammatory bowel disease

BACKGROUND

Bidirectional relationships between the immune system, nervous system, and psychological processes likely exist in inflammatory bowel disease (IBD) because stress can affect IBD, and IBD is associated with an increased risk of psychological difficulty. The field of psychoneuroimmunology (PNI) sheds light on specific mechanisms that are involved in these relationships, and this research can be applied specifically to IBD. The purpose of this article is to review research on PNI processes in IBD and provide recommendations for future research.

METHODS

A literature search was conducted using the PubMed and PsychInfo computerized databases and bibliographies of relevant articles.

RESULTS

The hypothalamic-pituitary-adrenal axis, sympathetic-adrenomedullary system, proinflammatory cytokines, substance P, and mast cells play roles in inflammatory processes in IBD. These processes also respond to stress, and they have been implicated in psychological problems in otherwise healthy individuals. These overlapping processes in inflammation and psychological function have received limited attention in IBD, but preliminary evidence suggests that these mechanisms may play a role in the psychological difficulty experienced by those with IBD.

CONCLUSIONS

Several bidirectional PNI mechanisms overlap in IBD, suggesting ways that stress and psychological function can affect disease activity and, conversely, avenues by which the inflammation in IBD may contribute to psychological difficulty. More research on specific PNI processes is needed to fully understand these factors in IBD.

Acute effects of calvarial damage on dural mast cells, pial vascular permeability, and cerebral cortical histamine levels in rats and mice

Neurological complications after mild head injury can include vasogenic edema and/or subsequent development of epilepsy, conditions associated with elevated histamine. In the present study we assessed the potential of mast cells located in the dura mater to contribute to elevated cortical histamine and breakdown of the blood-brain barrier after minor head injury, modeled by either a parietal craniectomy or producing a groove in (scoring) the parietal bone surface to model a grazing head injury. We measured the following effects at 5-20 min after a unilateral parietal craniectomy (rats) or unilateral scoring of the parietal bone (mice): (1) mast cell integrity in subjacent dura mater; (2) subjacent vs. contralateral histamine in dura mater and cerebral cortex; (3) vascular permeability of cerebral cortical blood vessels subjacent to the injury, and; (4) the effects of an H(2)-receptor antagonist on cerebral cortical vascular permeability.

RESULTS

Dural mast cells subjacent to the craniectomy became activated (degranulated) concomitant with (1) decreased histamine in dura mater subjacent to the craniectomy; (2) increased histamine in the subjacent cerebral cortex; and (3) extravasation of Evans blue-albumin which stained the subjacent cerebral cortex, indicating a localized breakdown of the blood-brain barrier. Similar results were observed in mice after scoring the parietal bone surface and, additionally, pretreatment with the histamine H(2)-receptor antagonist zolantadine (1 h before injury) dose-dependently inhibited extravasation of Evans blue-albumin. We conclude that even a minor grazing injury of the skull, in the absence of penetrating brain injury or concussion, can activate dural mast cells and elevate cortical histamine, a novel mechanism with potential contributions to neurotraumatic complications arising from a relatively minor or grazing head wound.

Endometriosis Is Associated With Prevalence of Comorbid Conditions in Migraine

OBJECTIVE

To examine the headache characteristics of women with migraine and endometriosis (EM), and differences in the prevalence of comorbid conditions between female migraineurs with EM, without EM and nonheadache controls.

BACKGROUND

Migraine and EM are common conditions in women of reproductive age, and both are influenced by ovarian hormones. The comorbidity of migraine and EM is newly recognized, but reasons for the association are uncertain.

METHODS

This is a cross-sectional study of female headache outpatients and healthy controls conducted at University of Toledo and Duke University in 2005 and 2006. After a headache specialist determined headache frequency and diagnosis (based on criteria of the second International Classification of Headache Disorders), patients completed a self-administered electronic survey with information on demographics, headache-related disability, menstrual disorders, premenstrual dysphoric disorder (PMDD), vascular event risk, and comorbid conditions, including irritable bowel syndrome (IBS), fibromyalgia (FM), chronic fatigue syndrome (CFS), interstitial cystitis (IC), depression, and anxiety.

RESULTS

Study enrolled 171 women with migraine and 104 controls. EM was reported more commonly in migraineurs than in controls (22% vs 9.6%, P < .01). Frequency of chronic headache was higher in migraineurs with EM compared to without EM (P= .002) and median headache-related disability scores were also higher in the EM group (P= .025). Symptoms of PMDD were more common in migraineurs, but frequency did not differ by EM status. Migraineurs with EM reported more menorrhagia, dysmenorrhea, and infertility compared to the migraine cohort without EM and to controls. Depression, anxiety, IBS, FM, CFS, and IC were more common in migraine with EM group than in controls. Anxiety (OR = 2.2, 95% CI 1.0-4.7), IC (OR = 10.6, 95% CI 1.9-56.5), and CFS (OR = 3.6, 95% CI 1.1-11.5) were more common in migraine with EM group, than in the cohort with migraine without EM.

CONCLUSION

Prevalence of EM is higher in women with migraine than in nonheadache controls. Migraineurs with EM have more frequent and disabling headaches, and are more likely to have other comorbid conditions affecting mood and pain, compared to migraineurs without EM.

A temporal framework for understanding the effects of stressful life events on inflammation in patients with multiple sclerosis

A growing literature reports that stressful life events are associated with exacerbation and the subsequent development of brain lesions in patients with multiple sclerosis (MS). The evolution an MS exacerbation occurs over a period of many months and involves many different biological processes that change over time. Likewise, the experience of stress also occurs over time, with an onset, a shift from acute to chronic in some cases, and resolution. Each of these phases is associated with unique biological features. Thus, the impact of stress on MS exacerbation may depend on the temporal trajectories of stress and MS exacerbation, and when the intersection between these two trajectories occurs. This paper presents a temporal model, along with three different temporal relationships and associated mechanisms by which stress may impact MS exacerbation. These include the onset of a stressor, which may be mediated by mast cell activation, the point that a stressor begins to become chronic, which may be mediated by glucocorticoid resistance in immune cells, and the resolution of the stressor, which may be mediated by a drop in cortisol. These three hypotheses are not necessarily mutually exclusive. Data on psychosocial mediators and moderators are also briefly reviewed and future research directions are discussed.

Bronchial hyperresponsiveness in irritable bowel syndrome

Extraintestinal symptoms are often found in patients with irritable bowel syndrome (IBS). Recent studies suggest that IBS is associated with bronchial hyperresponsiveness. But it is still arguable that the bronchial hyperresponsiveness is associated with IBS patients. The purpose of this study is to investigate the possible relationship between IBS and bronchial hyperresponsiveness. Forty-two patients with IBS and 42 control subjects were included in this study. All patients underwent pulmonary function, methacholine challenge, and skin prick tests. There was no statistical difference between the two groups with respect to percentage of all pulmonary function test parameters, including FEV(1)%, FCV%, FVC/FEV(1), and FEF(25 - 75)%. Only two persons in the alternating-type IBS patient group and one person in the control group tested positive in the methacholine provocation test. But all PC(20) values were above 16 mg/ml. These results do not demonstrate a relationship between bronchial hyperresponsiveness and IBS. However, a relationship might exist in a subpopulation of IBS patients.

Mast cells and mast cell mediators as targets of dietary supplements

OBJECTIVE

To review the increasing amount of data that support or dispel the use of dietary supplements in the treatment of inflammatory conditions that involve mast cells, such as allergies, arthritis, and chronic pelvic pain syndrome.

DATA SOURCES

A search was conducted in MEDLINE for natural substances, dietary supplements, flavonoids, and proteoglycans for their in vitro or in vivo effects on allergic and inflammatory conditions.

STUDY SELECTION

Studies were selected for inclusion because of the impact factor of the journal, the definitive nature of the findings, the soundness of the study design, and the expert opinion of the authors.

RESULTS

Dietary supplements include a large group of products, such as vitamins, minerals, plant, or animal extracts, as well as herbal preparations that are often called medicinal herbs. Many of the available dietary supplements contain a multitude of ingredients, the source and/or purity of which is seldom disclosed; some of these may have biologic effects of their own or may interact with other supplements or drugs, often leading to adverse effects. The most well-documented evidence published to date is on the inhibitory action of natural compounds, especially flavonoids, on mast cells and allergic symptoms. Some flavonoids have weak inhibitory activity, whereas others may have no benefit or may be detrimental. Sulfated proteoglycans could provide synergistic action but require formulations with increased absorption.

CONCLUSIONS

Combining the most active flavonoids with proteoglycans could be helpful in atopic and inflammatory conditions. However, a complete list of active ingredients and their source, purity, and exact concentration should be a requirement for nutraceuticals to standardize, compare, and promote their safe use.

Irritable bowel syndrome and bronchial hyperresponsiveness: is there a link?

BACKGROUND/AIM

Many studies have demonstrated a high prevalence of bronchial hyperresponsiveness in patients with irritable bowel syndrome (IBS). The aim of this 24-month prospective study was to evaluate the prevalence of IBS in asthmatic patients.

METHODS

We analyzed 623 asthmatic patients that were evaluated for body mass index, sex, and age before undergoing both a methacholine challenge test (MCHt) and skin prick tests.

RESULTS

We found that 276 asthmatic patients (44.3%) were positive on the MCHt, while 347 (55.7%) were negative. We also found that 27 (9.7%) of the 276 patients with a positive MCHt and 44 (12.7%) of the 347 patients with a negative MCHt were affected by IBS. Therefore, there was no statistically significant difference between positive MCHt tests and IBS. The PC(20) (mean provocation concentration of methacholine producing a 20% reduction in forced expiratory volume in 1 s < or =16 mg/ml) in all patients tested was 8.64 +/- 2.58 mg/ml, being 8.75 +/- 2.52 and 8.55 +/- 2.32 mg/ml for males and females, respectively.

CONCLUSIONS

These results do not demonstrate a relationship between MCHt and IBS. However, a relationship might still exist in a subpopulation of patients whose symptoms worsen by stress.

Critical role of mast cells in inflammatory diseases and the effect of acute stress

Mast cells are not only necessary for allergic reactions, but recent findings indicate that they are also involved in a variety of neuroinflammatory diseases, especially those worsened by stress. In these cases, mast cells appear to be activated through their Fc receptors by immunoglobulins other than IgE, as well as by anaphylatoxins, neuropeptides and cytokines to secrete mediators selectively without overt degranulation. These facts can help us better understand a variety of sterile inflammatory conditions, such as multiple sclerosis (MS), migraines, inflammatory arthritis, atopic dermatitis, coronary inflammation, interstitial cystitis and irritable bowel syndrome, in which mast cells are activated without allergic degranulation.

Corticotropin-releasing hormone and its structurally related urocortin are synthesized and secreted by human mast cells

Stress activates the hypothalamic-pituitary-adrenal axis through CRH, leading to production of glucocorticoids that down-regulate immune responses. However, acute stress also has proinflammatory effects. We previously showed that restraint stress, as well as CRH and its structurally related urocortin (Ucn), could activate mast cells and trigger mast cell-dependent vascular permeability. Here we show for the first time that human cord blood-derived cultured mast cells (hCBMC) at 10 wk, but not at 2 wk, are immunocytochemically positive for CRH and Ucn; human leukemic mast cells are weakly positive for both peptides. The ability of these mast cells to synthesize CRH and Ucn was confirmed by showing mRNA expression with RT-PCR. hCBMC (8-14 wk) synthesize and store 1-10 ng/106 cells (10-20 microg/g) of both CRH and Ucn detected by ELISA of cell homogenates. Stimulation of IgE-sensitized hCBMC with anti-IgE results in secretion of most CRH and Ucn. These findings indicate that mast cells are not only the target, but also a potential source of CRH and Ucn that could have both autocrine and paracrine functions, especially in allergic inflammatory disorders exacerbated by stress.

IL-1 Induces Vesicular Secretion of IL-6 without Degranulation from Human Mast Cells

Fc epsilon RI cross-linkage in mast cells results in release of granule-associated mediators, such as histamine and proteases, as well as the production of numerous cytokines, including IL-6. Mast cells have been increasingly implicated in inflammatory processes where explosive degranulation is not commonly observed. Here, we show that IL-1 stimulates secretion of IL-6 without release of the granule-associated protease tryptase in normal human umbilical cord blood-derived mast cells (hCBMCs). IL-6 secretion stimulated by IL-1 in hCBMCs is potentiated by priming with IL-4 and reflects the higher levels of IL-6 secreted from human leukemic mast cell line (HMC-1). Stimulating HMC-1 cells by both IL-1 and TNF-alpha results in synergistic secretion of IL-6. IL-6 is de novo synthesized, as its secretion is blocked by inhibitors of transcription or protein synthesis. IL-1 does not increase intracellular calcium ion levels in either hCBMCs or HMC-1 cells, and IL-6 stimulation proceeds in the absence of extracellular calcium ions. Ultrastructural Immunogold localization shows that IL-6 is excluded from the secretory granules and is compartmentalized in 40- to 80-nm vesicular structures. Selective secretion of IL-6 from mast cells appears distinct from degranulation and may contribute to the development of inflammation, where the importance of IL-6 has been recognized.

Neuropeptides: opportunities for drug discovery

The role of peptides as signalling molecules in the nervous system has been studied for more than 30 years. Neuropeptides and their G-protein-coupled receptors are widely distributed throughout the body and they commonly occur with, and are complementary to, classic neurotransmitters. The functions of neuropeptides range from neurotransmitter to growth factor. They are present in glial cells, are hormones in the endocrine system, and are messengers in the immune system. Much evidence indicates that neuropeptides are of particular importance when the nervous system is challenged (eg, by stress, injury, or drug abuse). These features and the large number of neuropeptides and neuropeptide receptors provide many opportunities for the discovery of new drug targets for the treatment of nervous-system disorders. In fact, receptor-subtype-selective antagonists and agonists have been developed, and recently a substance P receptor (neurokinin 1) antagonist has been shown to have clinical efficacy in the treatment of major depression and chemotherapy-induced emesis. Several other neuropeptide receptor ligands are in clinical trials for various indications.

High levels of intrauterine corticotropin-releasing hormone, urocortin, tryptase, and interleukin-8 in spontaneous abortions

Stress induces CRH secretion that activates hypothalamic-pituitary-adrenal axis and is also abortogenic. In addition to hypothalamus, CRH and its analog urocortin (Ucn) are also secreted locally outside the brain where they activate mast cells leading to inflammation; however, the level of CRH and Ucn or mast cell mediators has not been examined in products of conception (POC). CRH and Ucn were measured by enzyme immunoassay, tryptase by fluoroenzyme immunoassay, and IL-8 by ELISA in POC of 7-9 wk gestation from Caucasian women; they were divided into group I with elective abortions (n = 4), group II with one spontaneous abortion (n = 12), and group III with at least two spontaneous abortions (n = 7). CRH, Ucn, tryptase, and IL-8 levels were higher (P < 0.05) in group III (8683 +/- 1201 pg/g, 7961 +/- 1499 pg/g, 1553 +/- 572 ng/g, and 8317 +/- 1874 pg/g, respectively) than group II (2561 +/- 314 pg/g, 2349 +/- 394 pg/g, 403 +/- 97 ng/g, and 3199 +/- 449 pg/g, respectively) and group I (163 +/- 162 pg/g, 328 +/- 327 pg/g, 72 +/- 31 ng/g, and 3681 +/- 931 pg/g, respectively). Immunostaining of POC showed significantly more tryptase in group III women. High POC levels of CRH and Ucn under stress in habitual spontaneous abortions may activate uterine mast cells to secrete abortogenic tryptase and IL-8.

IL-10, an inflammatory/inhibitory cytokine, but not always

IL-10 has been previously called cytokine synthesis inhibiting factor, produced mostly by Th2 cells, macrophages and CD8+ cell clones. IL-10 is capable of inhibiting the synthesis of several cytokines from different cells, antigen or mitogen activated. IL-10 exerts its inhibition at the mRNA transcriptional and translational level. In addition, IL-10 is a co-stimulatory cytokine on activated T cells. For example, IL-10 inhibits NK cell activity, the production of Th1 cytokines, cytokines generated by peripheral blood mononuclear cells, and macrophage activity. On the other hand, IL-10 exerts immunostimulatory effects on B cells, cytotoxic T cell development and thymocytes. In mast cells derived from CD4+/CD133+ cells, IL-10 inhibits IL-6 and TNFalpha, and prostaglandin E(1) and E(2) induced by IL-6. Here, we report for the first time that IL-10 fails to inhibit tryptase and IL-6 from human mast cell-1 (HMC-1) and human umbilical cord blood-derived mast cells.

Remodelling and Inflammation in Bronchial Asthma

Chronic stable asthma is characterized by inflammation of the airway wall, with abnormal accumulation of basophils, eosinophils, lymphocytes, mast cells, macrophages, dendritic cells and myofibroblasts. The airway inflammation is not confined to severe asthma, but is also found in mild and moderate asthma. This inflammation results in a peculiar type of lymphocytic infiltration whereby Th2 lymphocytes secrete cytokines that orchestrate cellular inflammation and promote airway hyperresponsiveness.

The term “airway remodelling” in bronchial asthma refers to structural changes that occurr in conjunction with, or because of, chronic airway inflammation. Airway remodelling results in alterations in the airway epithelium, lamina propria, and submucosa, leading to thickening of airway wall. The consequences of airway remodelling in asthma include incompletely reversible airway narrowing, bronchial hyperresponsiveness (BHR), smooth muscle contraction, airway edema, and mucus hypersecretion which may predispose persons with asthma to exacerbations and even death from airway obstruction.

Corticotropin-releasing hormone and brain mast cells regulate blood-brain-barrier permeability induced by acute stress

Stress activates the hypothalamic-pituitary-adrenal axis through release of corticotropin releasing hormone (CRH), leading to production of glucocorticoids that down-regulate immune responses. Acute stress, however, also has proinflammatory effects that seem to be mediated through the activation of mast cells. Stress and mast cells have been implicated in the pathophysiology of various inflammatory conditions, including some in the central nervous system, such as multiple sclerosis in which disruption of the blood-brain barrier (BBB) precedes clinical symptoms. We previously showed that acute restraint stress increases rat BBB permeability to intravenous 99Tc gluceptate and that administration of the "mast cell stabilizer" disodium cromoglycate (cromolyn) inhibits this effect. In this study, we show that the CRH-receptor antagonist Antalarmin blocks stress-induced 99Tc extravasation, whereas site-specific injection of CRH in the paraventricular nucleus (PVN) of the hypothalamus mimics acute stress. This latter effect is blocked by pretreatment of the PVN with cromolyn; moreover, restraint stress cannot disrupt the BBB in the diencephalon and cerebellum of W/W(v) mast cell-deficient mice. These results demonstrate that CRH and mast cells are involved in regulating BBB permeability and, possibly, brain inflammatory disorders exacerbated by acute stress.

Topical immunopharmacology of ocular allergies

PURPOSE OF REVIEW

To review the histamine-1 receptor antagonists, mast cell blockers and natural agents with such actions that can be used for the topical treatment of ocular allergies.

RECENT FINDINGS

Increasing evidence indicates that some histamine-1 receptor antagonists have additional actions to inhibit secretion of inflammatory mediators, especially cytokines, from ocular mast cells and other cell types. Emerging information suggests that such actions may be through regulation of intracellular calcium ion levels of NF-kappaB activation.

SUMMARY

A number of available drugs and natural non-prescription agents may have anti-histaminic and anti-inflammatory actions.

Mast cells: new targets for multiple sclerosis therapy?

Growing evidence suggests that mast cells (MCs) play a crucial role in the inflammatory process and the subsequent demyelination observed in patients suffering from multiple sclerosis (MS). Although no consensus exists on the role of mast cells in multiple sclerosis, recent results from animal models clearly indicate that these cells act at multiple levels to influence both the induction and the severity of disease. In addition to changing our views on the pathophysiology of multiple sclerosis, the concept that mast cells are critical for the outcome of the disease could have an important impact on the development of new therapeutic approaches.

Mast cell deficient W/W(v) mice lack stress-induced increase in serum IL-6 levels, as well as in peripheral CRH and vascular permeability, a model of rheumatoid arthritis

Corticotropin releasing hormone (CRH) and interleukin-6 (IL-6) are implicated in inflammatory diseases triggered by stress. Acute restraint stress increases serum IL-6 in the blood, but its source is not known. Our current study was carried out in order to determine the contribution of mast cells to stress-induced IL-6 release and to investigate skin CRH and vascular permeability in mice. W/W(v) mast cell deficient and their wild type control +/+ mice were stressed in a plexiglass restraint chamber for 60 or 120 min. Serum corticosterone and IL-6 levels were measured. Other mice were injected with (99)Tchnetium gluceptate ((99)Tc) and its extravastion, indicating vascular permeability, was determined along with CRH levels in the skin and knee joints. Acute stress increased serum IL-6 in mice, but was greatly inhibited in W/W(v) mast cell deficient mice. Vascular permeability to (99)Tc, as well as local CRH levels, were also increased by stress, but not in W/W(v) mice. Findings from our current study suggest a link between mast cells and stress-related skin and joint inflammation and may explain initial events in psoriatic and rheumatoid arthritis.

Serum interleukin-6 reflects disease severity and osteoporosis in mastocytosis patients

BACKGROUND

Systemic mastocytosis (SM) is a condition typically characterized by an increased number of mast cells in the bone marrow or in skin areas known as urticaria pigmentosa. Patients may present with flushing, itching, gastrointestinal symptoms, arrhythmias, headaches and osteoporosis. Some patients experience systemic symptoms indicative of SM in the absence of a positive bone marrow or skin biopsy, and are known as 'clinical mastocytosis', but are herein referred to as suspected of having systemic mastocytosis. Serum tryptase has been increasingly used as a biochemical marker of mastocytosis, but is not always elevated.

OBJECTIVE

To investigate the association of serum levels of two key mast cell mediators, interleukin-6 (IL-6) and tryptase, to each other and with disease severity in patients with mastocytosis.

METHODS

Patients responded to an announcement from the Systemic Mastocytosis Society (USA) and submitted frozen serum samples, but the precise diagnosis made by their own health providers was not known until after the assays were completed. There were 9 suspected systemic mastocytosis (SuSM), 3 cutaneous mastocytosis (CM), 11 indolent systemic mastocytosis (ISM), and 3 aggressive systemic mastocytosis (ASM). Five normal volunteers (3 females/2 males) also submitted samples, as did 33 cardiac patients without coronary artery disease. For 2 days prior to and during the collection period, mastocytosis patients were asked to abstain from any over-the-counter or food products containing biogenic amines, as well as drugs prescribed for this condition. Serum levels of IL-6 and tryptase were measured using established assays.

RESULTS

Twenty-six patients (14 females/12 males) submitted serum samples. There were 9 cases of SuSM (6 females/3 males) in whom tryptase values were borderline normal; IL-6 values were slightly elevated with one being high. In 3 cases of CM (2 females/1 male), both tryptase and IL-6 were slightly elevated. In patients with ISM (5 females/6 males), only 6/11 had any tryptase elevated significantly as compared to 9/11 with elevated serum IL-6. Three patients with ASM had significant elevations of both IL-6 and tryptase. The most consistent finding was that of IL-6 elevations in 7/7 patients (3 females/4 males) who reported symptoms of osteoporosis and/or bone pain (1 SuSM, 3 ISM, 3 ASM) in the absence of any coexisting condition involving bone pathology.

CONCLUSION

Serum IL-6 is elevated in mastocytosis patients and correlates with severity of symptoms and the presence of osteoporosis. High serum IL-6 may not only signify disease progression, but may also participate in the pathophysiology of mastocytosis.