Mast cells and metabolic syndrome

Mast cells are critical effectors in the development of allergic diseases and in many immunoglobulin E-mediated immune responses. These cells exert their physiological and pathological activities by releasing granules containing histamine, cytokines, chemokines, and proteases, including mast cell-specific chymase and tryptase. Like macrophages and T lymphocytes, mast cells are inflammatory cells, and they participate in the pathogenesis of inflammatory diseases such as cardiovascular complications and metabolic disorders. Recent observations suggested that mast cells are involved in insulin resistance and type 2 diabetes. Data from animal models proved the direct participation of mast cells in diet-induced obesity and diabetes. Although the mechanisms by which mast cells participate in these metabolic diseases are not fully understood, established mast cell pathobiology in cardiovascular diseases and effective mast cell inhibitor medications used in pre-formed obesity and diabetes in experimental models offer hope to patients with these common chronic inflammatory diseases. This article is part of a Special Issue entitled: Mast cells in inflammation.

Breaking patterns of environmentally influenced disease for health risk reduction: immune perspectives

BACKGROUND

Diseases rarely, if ever, occur in isolation. Instead, most represent part of a more complex web or "pattern" of conditions that are connected via underlying biological mechanisms and processes, emerge across a lifetime, and have been identified with the aid of large medical databases.

OBJECTIVE

We have described how an understanding of patterns of disease may be used to develop new strategies for reducing the prevalence and risk of major immune-based illnesses and diseases influenced by environmental stimuli.

FINDINGS

Examples of recently defined patterns of diseases that begin in childhood include not only metabolic syndrome, with its characteristics of inflammatory dysregulation, but also allergic, autoimmune, recurrent infection, and other inflammatory patterns of disease. The recent identification of major immune-based disease patterns beginning in childhood suggests that the immune system may play an even more important role in determining health status and health care needs across a lifetime than was previously understood.

CONCLUSIONS

Focusing on patterns of disease, as opposed to individual conditions, offers two important venues for environmental health risk reduction. First, prevention of developmental immunotoxicity and pediatric immune dysfunction can be used to act against multiple diseases. Second, pattern-based treatment of entryway diseases can be tailored with the aim of disrupting the entire disease pattern and reducing the risk of later-life illnesses connected to underlying immune dysfunction. Disease-pattern-based evaluation, prevention, and treatment will require a change from the current approach for both immune safety testing and pediatric disease management.

Monocytes in metabolic disorders--opportunities for flow cytometry contributions

Chronic inflammation has arised as a major underlying cause of atherosclerosis, obesity and diabetes. It is mediated by cells of innate immune system like macrophages but also by their antecedents, circulating monocytes. Roles of monocyte subsets and different markers of monocyte activation in the context of metabolic disorders have been reviewed. Applying cell based approach through flow cytometry in this field has resulted with new understanding of pathophysiologic mechanisms. Possible implications of these insights in diagnosis, prognosis and revealing of therapeutic targets in metabolic disorders remain a challenge for future.

Immunochemical termination of self-tolerance

The ability to selectively induce a strong immune response against self-proteins, or increase the immunogenicity of specific epitopes in foreign antigens, would have a significant impact on the production of vaccines for cancer, protein-misfolding diseases, and infectious diseases. Here, we show that site-specific incorporation of an immunogenic unnatural amino acid into a protein of interest produces high-titer antibodies that cross-react with WT protein. Specifically, mutation of a single tyrosine residue (Tyr(86)) of murine tumor necrosis factor-alpha (mTNF-alpha) to p-nitrophenylalanine (pNO(2)Phe) induced a high-titer antibody response in mice, whereas no significant antibody response was observed for a Tyr(86) --> Phe mutant. The antibodies generated against the pNO(2)Phe are highly cross-reactive with native mTNF-alpha and protect mice against lipopolysaccharide (LPS)-induced death. This approach may provide a general method for inducing an antibody response to specific epitopes of self- and foreign antigens that lead to a neutralizing immune response.

Gravinol ameliorates high-fructose-induced metabolic syndrome through regulation of lipid metabolism and proinflammatory state in rats

Using a rat model with fructose-induced metabolic syndrome, the effect of gravinol was investigated. Male Wistar rats were fed a 65% fructose diet and administered 10 or 20 mg of gravinol/kg of body weight/day for 2 weeks. High-level fructose feeding led to hyperglycemia, hyperlipidemia, hypertri-glyceridemia, and hypertension. On the other hand, the administration of gravinol significantly lowered serum glucose and total cholesterol levels. The tail arterial blood pressure was significantly elevated with the high-fructose diet. However, rats given gravinol showed a lower blood pressure as compared with fructose-fed control rats. In addition, the triglyceride (TG) levels in serum and lipoprotein fraction were dose-dependently reduced in rats fed gravinol. The decreases of hepatic TG and total cholesterol by gravinol were responsible for the down-regulation of hepatic sterol regulatory element binding protein (SREBP)-1. However, gravinol did not affect the protein levels of hepatic peroxisome proliferator-activated receptor-alpha and SREBP-2. Moreover, gravinol administration in the fructose-fed rats markedly reduced the glycosylated protein and thiobarbituric acid-reactive substance levels in the serum and hepatic mitochondria, and it inhibited the increase of the cyclooxygenase-2 protein level as a result of the down-regulation of nuclear factor kappa B (NF-kappaB). Furthermore, the decrease of anti-apoptotic bcl-2 protein levels and the increase of pro-apoptotic bax protein levels by the high-fructose diet were reversed by gravinol. These findings suggest that fructose-induced metabolic syndrome is attenuated by gravinol administration, which is associated with the reduction of serum lipids and protection against the proinflammatory state induced by oxidative stress.

Neonatal programming of neuroimmunomodulation--role of adipocytokines and neuropeptides

Programming is an epigenetic phenomenon by which nutrition, environment and stress acting in a critical period earlier in life change the organism's development. This process was evolutionarily selected as an adaptive tool for the survival of organisms living in nutritionally deficient areas and submitted to stressful conditions. Thus, perinatal malnutrition turns on different genes that provide the organism with a thrifty phenotype. In conditions of abundant supply of nutrients, those programmed organisms can be at risk of developing metabolic diseases (obesity, dyslipidemia, diabetes and hypertension). How nutrition or neonatal stress can program the immune system is less well known. Here, we discuss some of the hormonal and metabolic changes that occur in mothers and neonates and how those factors can imprint hormonal or metabolic changes that program neuroimmunomodulatory effects. Some of these changes involve thyroid hormones, leptin, insulin, glucocorticoids and prolactin as potential imprinting factors. Most of them can be transferred through the milk and may change with malnutrition or stress. We discuss the programming effects of these hormones upon body weight, body composition, insulin action, thyroid, adrenal and immune and inflammatory responses, with special emphasis on leptin, a cytokine that seems to play a central role in these events.

Results of an international, randomized trial comparing glucose metabolism disorders and outcome with cyclosporine versus tacrolimus

DIRECT (Diabetes Incidence after Renal Transplantation: Neoral C(2) Monitoring Versus Tacrolimus) was a 6-month, open-label, randomized, multicenter study which used American Diabetes Association/World Health Organization criteria to define glucose abnormalities. De novo renal transplant patients were randomized to cyclosporine microemulsion (CsA-ME, using C(2) monitoring) or tacrolimus, with mycophenolic acid, steroids and basiliximab. The intent-to-treat population comprised 682 patients (336 CsA-ME, 346 tacrolimus): 567 were nondiabetic at baseline. Demographics, diabetes risk factors and steroid doses were similar between treatment groups. The primary safety endpoint, new-onset diabetes after transplant (NODAT) or impaired fasting glucose (IFG) at 6 months, occurred in 73 CsA-ME patients (26.0%) and 96 tacrolimus patients (33.6%, p = 0.046). The primary efficacy endpoint, biopsy-proven acute rejection, graft loss or death at 6 months, occurred in 43 CsA-ME patients (12.8%) and 34 tacrolimus patients (9.8%, p = 0.211). Mean glomerular filtration rate (Cockcroft-Gault) was 63.6 +/- 20.7 mL/min/1.73 m(2) in the CsA-ME cohort and 65.9 +/- 23.1 mL/min/1.73 m(2) with tacrolimus (p = 0.285); mean serum creatinine was 139 +/- 58 and 133 +/- 57 mumol/L, respectively (p = 0.005). Blood pressure was similar between treatment groups at month 6, but total cholesterol, LDL-cholesterol and triglyceride levels were significantly higher with CsA than with tacrolimus (total cholesterol:HDL remained unchanged). The profile and incidence of adverse events were similar between treatments. The incidence of NODAT or IFG at 6 months post-transplant is significantly lower with CsA-ME than with tacrolimus without a significant difference in short-term outcome.

Innate immune system regulation of nuclear hormone receptors in metabolic diseases

The immune system modulates a number of biological processes to properly defend against pathogens. Here, we review how crosstalk between nuclear hormone receptors and the innate immune system may influence multiple biological functions during an immune response. Although nuclear hormone receptor repression of innate immune responses and inflammation has been well studied, a number of new studies have identified repression of nuclear hormone receptor signaling by various innate immune responses. IFN regulatory factor 3, a key transcription factor involved in the induction of antiviral genes, may play a role in mediating such crosstalk between the innate immune response and nuclear receptor-regulated metabolism. This crosstalk mechanism is now implicated in the pathogenesis of atherosclerosis and Reye's syndrome and could provide an explanation for other pathogen-associated metabolic and developmental disorders.

Solar cycles and their relationship to human disease and adaptability

In this paper, we show that 11-year solar cycle peaks predispose humans to disease, but also endow creativity and adaptability. We give several examples of diseases that are modulated by light and present evidence for an effect of intensity and variation in sunlight, primarily ultraviolet radiation (UVR), on the human genome. The birth dates of nearly 237,000 unique clients in the Maine Medicaid database collected from 1995 to 2004, inclusive, were related to solar cycle irradiance for the past seventy-one years, encompassing seven solar cycles. The sample was divided into four general categories of disease: mental/behavioral illnesses; metabolic diseases; autoimmune diseases; neoplasms. The birth months for those clients born in any given year were arranged in the form of a winter/summer ratio in order to more clearly appreciate the seasonality inherent in each disease category. Solar cycles were separated into chaotic (approximately three times as irradiant) or non-chaotic according to the Gutenberg-Richter power law and the uncertainty inherent in predicting solar storms. The results show that radiation peaks in solar cycles and particularly in chaotic solar cycles (CSCs) are associated with a higher incidence of mental disorders, suggesting the sensitivity of ectodermal embryonic tissues to UVR. Autoimmune diseases have intermediate sensitivity, while the neoplasms in the study, primarily of endoderm, appear suppressed by peak UVR intensity. The ratio of the number of clients born in CSC cycles to non-CSC cycles was highest for the more genetic mental diseases, like schizophrenia and bipolar disorder, but as that ratio decreased, the clients with diseases like multiple sclerosis and rheumatoid arthritis showed more environmental features manifested as a greater winter/summer birth month ratio that was significantly different than that of the average client in the whole data set. The paper presents evidence that latitude, e.g., variation in light, is an added stress to the immune system (especially at 53-54 degrees N. latitude) that is involved in nearly all human disease. We hypothesize that introns, the presumptive engenderers of gene control, modulate the effects of UVR, particularly for the neoplasms studied. We conclude that intermittent and largely unpredictable peak solar cycle radiation has been the fundamental engine of evolution, forcing organisms to adapt to mutagenic UVR and producing enough damage to instigate genetic variation. Probably a chance genetic mutation over 80,000 years ago produced a human brain capable of abstract thought and consciousness. The slight genetic instability that favored an adaptable, creative brain also produced other somatic variations that present phenotypically as disease, but largely expressed after natural selection (reproduction) and associated with the inexorable entropy of aging.

[Widal triad (Asthma-Nasal polyposis-aspirin intolerance): an inflammatory metabolism abnormality]

Widal disease is characterized by symptomatic triad of aspirin intolerance, nasal polyposis and asthma. This disease is closely linked to abnormalities of the arachidonic acid metabolism. Partly of genetic origin, these anomalies are also related to the immune system function and probably to age. These factors induce an increase of cysleukotriene synthetase enzyme, and consequently an overproduction of cysleukotrienes that have both proinflammatory and bronchoconstrictive effects. In recent years, encouraging results were obtained with anti-leukotrienes, especially when they are associated with topic corticosteroids. Finally, numerous research that attempt to reach a better understanding of arachidonic acid metabolism are underway, which enables us to hope for future therapeutic advances.

Recognition of the immunocompromised patient

The host defense systems in humans are highly specialized with respect to categories of infectious pathogens; yet, there is just enough overlap to protect one from minor defects. It is also important to appreciate that not all abnormalities reported from the laboratory are clinically significant. By appreciating the clinical syndromes that accompany various deficiencies, the surgeon can be aware of the at-risk patient.

The role of the Th-1 to Th-2 shift of the cytokine profiles of CD4 helper cells in the pathogenesis of autoimmune and hypercatabolic diseases

The task of the immune system is the continuous elimination of endogenous cellular debris and the elimination, when necessary, of exogenous structures. It therefore seems useful and practical to add to the paradigms 'self' and 'not self' the term 'altered self'. The concept of stress, introduced by W. B. Cannon and H. Selye in the 1930s, covers the wide range of aggressive environmental influences which for their part result in a uniform shift of the metabolism in the direction of catabolism. This results from the activation of the neuroendocrine stress axis, hypothalamus-pituitary-adrenals, and causes an increased release of catecholamines and glucocorticoids. These latter substances limit life-threatening acute-phase reactions by endogenous inflammation mediators. The purpose of the shift of the cytokine profiles of the CD4 lymphocytes from Th-1 to Th-2 is, with the return of a raised cortisol level to normal values, to temporarily take over the anti-inflammatory functions of the cortisol. A sustained Th-2 shift is an expression of a persistent hypercortisolism in autoimmune states. The suppression of the anti-inflammatory effects of cortisol as a result of states of excessive stress leads to hypercatabolic diseases such as AIDS, sepsis and toxic shock syndrome and protein calorie malnutrition (NAIDS). In the prevention and treatment of AIDS and NAIDS, besides the elimination of the causes of stress, the prophylactic and therapeutic efforts are based mainly on the activation of the mesenchymal production of anabolic matrix components, mainly glycosaminoglycans, and the neutralization of O2 and NO radicals and inflammation mediators from macrophages by polyanions and polyphenols. In our opinion, in sepsis and toxic shock syndromes, lasting reduction of the mortality rates for these diseases is best achieved through the early administration of high intravenous doses of gammaglobulins.

[Determination of natural antibodies to catecholamines in health and disease]

AIM

Enzyme immunoassay (EIA) determination of the level of natural antibodies (n-Ab) to catecholamines in patients with metabolic disturbances and cardiovascular diseases, correlation between content of n-Ab to these bioregulators and clinical diagnosis, biochemical indices.

MATERIALS AND METHODS

EIA with specially synthetized artificial antigens was used to determine n-Ab to catecholamines (adrenaline, noradrenaline, dopamin) in 41 patients with cardiovascular diseases and metabolic disturbances (ischemic heart disease, essential hypertension, hyperlipoproteinemia) and in 10 healthy subjects (donors, controls).

RESULTS

Changes in the levels of antibodies to catecholamines correspond to the clinical diagnosis. Interrelations exist between n-Ab to catecholamines and biochemical parameters in the disease.

CONCLUSION

The trends in the amount of n-Ab to catecholamines are a unique marker of metabolic disturbances of these endogenic substances and can be used in diagnosis.

Homocarnosinosis patients and great apes have a serum protein that cross-reacts with human serum carnosinase

A specific polyclonal antiserum to human serum carnosinase was raised in rabbits and was used to prepare an agarose-protein A-antibody matrix. An antigen capture procedure showed that sera from homocarnosinosis patients, which lack carnosinase activity, contain an immunoreactive protein (M(r) 75,000) indistinguishable from the carnosinase band from normal serum. Other higher primates have active serum carnosinase and a similar immunoreactive M(r) 75,000 protein. The immunoaffinity matrix was used in a facile procedure to isolate pure carnosinase from human plasma with a yield of 69%. The antiserum inhibited human serum carnosinase strongly, but the maximum inhibition attained averaged only 71%. The antiserum inhibited human and chimpanzee serum carnosinases more effectively than gorilla or other higher primate serum carnosinases.

Immunology and immunogenetics in metabolic diseases

The first part of the work reviews some general data regarding the HLA system and emphasizes the principal implications of this system in diabetes mellitus and other metabolic diseases. Part two discusses pathoimmunological mechanisms in metabolic pathology (on the one hand those linked to autoimmunity, on the other those linked to immunologic deficiency of enzymatic origin). Finally, some immunologic aspects in the treatment of metabolic diseases are outlined.

[Skin changes in paraproteinemias (monoclonal gammopathies)]

Numerous skin disorders or skin lesions are associated with a monoclonal gammopathy (formerly: paraproteinemia). These skin diseases can be differentiated in the following way: specific skin lesions caused by monoclonal immunoglobulin producing cells in the skin, in generalized plasmocytoma or morbus Waldenström. In another group of disorders the monoclonal immunoglobulins induce functional disturbances, e.g. Raynaud syndrome (if the monoclonal immunoglobulins are cryoglobulins), xanthomatosis through interactions between these immunoglobulins and lipoproteins, purpura in immunoglobulin induced stasis and hyperviscosity. The unlimited spreading of the plasmocytoma cells replaces normal immunoglobulin producing plasma cells followed by a disturbance of the humoral immune response, which is frequently accompanied by atypical infections of skin or other organs. Furthermore, an almost obligatory association with monoclonal gammopathies has been demonstrated in a few skin diseases, e.g. scleromyxedema. However, the role of the immunoglobulins in these disorders is unknown. In some other skin diseases, such as pyoderma gangrenosum, acrodermatitis atrophicans Herxheimer, scleredema Buschke etc., a monoclonal gammopathy is only detectable in some patients.

Chemotaxis: basic aspects of methodology, mechanisms and pathology

This review is an attempt to discuss the basic conceptual tools that are a prerequisite for any clinical study of chemotactic defects. They include familiarity with definitions of common terms and with the merits and drawbacks of the several possible in vivo and in vitro assay methods. Cellular mechanisms involved in locomotion are complex. They include basic requirements for cell metabolism as well as receptor recognition, attachment to surfaces and contraction of the cytoskeleton of the cell. Of the many chemotactic factors reported, few are well characterized and universally agreed upon. Similarly, with the use of more stringent criteria, a number of clinical defects of chemotaxis have proven transitory or even artifactual.