Human leptin enhances activation and proliferation of human circulating T lymphocytes

Obesity, Fat Mass and Immune System: Role for Leptin

Obesity is an epidemic disease characterized by chronic low-grade inflammation associated with a dysfunctional fat mass. Adipose tissue is now considered an extremely active endocrine organ that secretes cytokine-like hormones, called adipokines, either pro- or anti-inflammatory factors bridging metabolism to the immune system. Leptin is historically one of most relevant adipokines, with important physiological roles in the central control of energy metabolism and in the regulation of metabolism-immune system interplay, being a cornerstone of the emerging field of immunometabolism. Indeed, leptin receptor is expressed throughout the immune system and leptin has been shown to regulate both innate and adaptive immune responses. This review discusses the latest data regarding the role of leptin as a mediator of immune system and metabolism, with particular emphasis on its effects on obesity-associated metabolic disorders and autoimmune and/or inflammatory rheumatic diseases.

Emergence of Leptin in Infection and Immunity: Scope and Challenges in Vaccines Formulation

Deficiency of leptin (ob/ob) and/or desensitization of leptin signaling (db/db) and elevated expression of suppressor of cytokine signaling-3 (SOCS3) reported in obesity are also reported in a variety of pathologies including hypertriglyceridemia, insulin resistance, and malnutrition as the risk factors in host defense system. Viral infections cause the elevated SOCS3 expression, which inhibits leptin signaling. It results in immunosuppression by T-regulatory cells (Tregs). The host immunity becomes incompetent to manage pathogens' attack and invasion, which results in the accelerated infections and diminished vaccine-specific antibody response. Leptin was successfully used as mucosal vaccine adjuvant against Rhodococcus equi. Leptin induced the antibody response to Helicobacter pylori vaccination in mice. An integral leptin signaling in mucosal gut epithelial cells offered resistance against Clostridium difficile and Entameoba histolytica infections. We present in this review, the intervention of leptin in lethal diseases caused by microbial infections and propose the possible scope and challenges of leptin as an adjuvant tool in the development of effective vaccines.

Adipokines and inflammation: is it a question of weight?

Obesity has reached epidemic proportions in the Western society and is increasing in the developing world. It is considered as one of the major contributors to the global burden of disability and chronic diseases, including autoimmune, inflammatory and degenerative diseases. Research conducted on obesity and its complications over the last two decades has transformed the outdated concept of white adipose tissue (WAT) merely serving as an energy depot. WAT is now recognized as an active and inflammatory organ capable of producing a wide variety of factors known as adipokines. These molecules participate through endocrine, paracrine, autocrine or juxtacrine crosstalk mechanisms in a great variety of physiological or pathophysiological processes, regulating food intake, insulin sensitivity, immunity and inflammation. Although initially restricted to metabolic activities (regulation of glucose and lipid metabolism), adipokines currently represent a new family of proteins that can be considered key players in the complex network of soluble mediators involved in the pathophysiology of immune/inflammatory diseases. However, the complexity of the adipokine network in the pathogenesis and progression of inflammatory diseases has posed, since the beginning, the important question of whether it may be possible to target the mechanism(s) by which adipokines contribute to disease selectively without suppressing their physiological functions. Here, we explore in depth the most recent findings concerning the involvement of adipokines in inflammation and immune responses, in particular in rheumatic, inflammatory and degenerative diseases. We also highlight several possible strategies for therapeutic development and propose that adipokines and their signalling pathways may represent innovative therapeutic strategies for inflammatory disorders.

Leptin in inflammation and autoimmunity

After its discovery as a key controller of metabolic function, leptin has been later extensively implicated in additional functions including important modulatory activities on the innate and adaptive immune response. This review analyzes the known implications of leptin in multiple inflammatory conditions, including autoimmune diseases, and how this knowledge could be instrumental in the design of leptin-based manipulation strategies to help restoration of abnormal immune responses.

Leptin in autoimmune mechanisms of systemic rheumatic diseases

In the last two decades, white adipose tissue (WAT) has been recognized as a key actor of many physiological and pathological conditions. WAT is able to produce mediators, named "adipokines", which may affect systemic homeostasis. In particular, leptin is not only involved in appetite and energy metabolism, but also in immune system. Increasing evidence established that leptin can regulate both innate and adaptive immunity mainly with pro-inflammatory effects but also, to a lesser extent, with anti-inflammatory features. In autoimmune diseases, a failure or breakdown of the mechanisms of self-tolerance is observed. Leptin, which plays an important role in the control of immune balance, has been involved in autoimmunity generation and maintenance. In this review, it has been provided an up-to-date report about the role of leptin in systemic autoimmune diseases, with particular reference to connective tissue diseases, inflammatory arthritis, and vasculitis.

Protective Capacity of Statins during Pneumonia Is Dependent on Etiological Agent and Obesity

Acute respiratory infections are a leading cause of death worldwide. Clinical data is conflicted regarding whether statins improve outcomes for pneumonia. Potential confounding factors including specific etiology of pneumonia as well as obesity could potentially mask protective benefit. Obesity is a risk factor for high cholesterol, the main target for statin therapy. We demonstrate that statin intervention conferred no protective benefit in the context of wild-type mice regardless of infectious agent. Statin intervention conferred either a protective benefit, during influenza infection, or detrimental effect, in the case of pneumococcal infection, in obese animals. These data suggest etiology of pneumonia in the context of obesity could be dramatically altered by the protective effects of statin therapy during bacterial and viral pneumonia.

Leptin action in normal and pathological pregnancies

Leptin is now considered an important signalling molecule of the reproductive system, as it regulates the production of gonadotrophins, the blastocyst formation and implantation, the normal placentation, as well as the foeto-placental communication. Leptin is a peptide hormone secreted mainly by adipose tissue, and the placenta is the second leptin-producing tissue in humans. Placental leptin is an important cytokine which regulates placental functions in an autocrine or paracrine manner. Leptin seems to play a crucial role during the first stages of pregnancy as it modulates critical processes such as proliferation, protein synthesis, invasion and apoptosis in placental cells. Furthermore, deregulation of leptin levels has been correlated with the pathogenesis of various disorders associated with reproduction and gestation, including polycystic ovary syndrome, recurrent miscarriage, gestational diabetes mellitus, pre-eclampsia and intrauterine growth restriction. Due to the relevant incidence of the mentioned diseases and the importance of leptin, we decided to review the latest information available about leptin action in normal and pathological pregnancies to support the idea of leptin as an important factor and/or predictor of diverse disorders associated with reproduction and pregnancy.

The Immunome in Two Inherited Forms of Pulmonary Fibrosis

The immunome (immune cell phenotype, gene expression, and serum cytokines profiling) in pulmonary fibrosis is incompletely defined. Studies focusing on inherited forms of pulmonary fibrosis provide insights into mechanisms of fibrotic lung disease in general. To define the cellular and molecular immunologic phenotype in peripheral blood, high-dimensional flow cytometry and large-scale gene expression of peripheral blood mononuclear cells and serum proteomic multiplex analyses were performed and compared in a cohort with familial pulmonary fibrosis (FPF), an autosomal dominant disorder with incomplete penetrance; Hermansky-Pudlak syndrome pulmonary fibrosis (HPSPF), a rare autosomal recessive disorder; and their unaffected relatives. Our results showed high peripheral blood concentrations of activated central memory helper cells in patients with FPF. Proportions of CD38⁺ memory CD27^- B-cells, IgA⁺ memory CD27⁺ B-cells, IgM⁺ and IgD⁺ B-cells, and CD39⁺ T helper cells were increased whereas those of CD39^- T helper cells were reduced in patients affected with either familial or HPSPF. Gene expression and serum proteomic analyses revealed enrichment of upregulated genes associated with mitosis and cell cycle control in circulating mononuclear cells as well as altered levels of several analytes, including leptin, cytokines, and growth factors. In conclusion, dysregulation of the extra-pulmonary immunome is a phenotypic feature of FPF or HPSPF. Further studies investigating the blood immunome are indicated to determine the role of immune system dysregulation in the pathogenesis of pulmonary fibrosis.

Clinical Trial Registration

www.ClinicalTrials.gov, identifiers NCT00968084, NCT01200823, NCT00001456, and NCT00084305.

Leptin affects filopodia and cofilin in NK-92 cells in a dose- and time-dependent manner

Hyperleptinemia, associated with obesity, is related with immune dysfunction and carcinogenesis. Natural Killer (NK) cells, a major component of the innate immune system are mediators of anti-tumor immunity and the most actively migrating cells among leukocytes. Actin rearrangement, promoted by cofilin plays a central role in cellular migration. Leptin affects the phosphorylation-dependent activity of cofilin and thus actin remodeling. We used human NK-92 cells to explore the in vitro effects of leptin on co-localization of cofilin and F-actin and on morphological changes in NK cells. NK-92 cells were incubated with different leptin concentrations (10 and 100 ng/mL) for 30 min and 24 h and immunocytochemically stained. Results demonstrate a dose- and time-dependent influence of leptin on cellular morphology. Utilizing confocal microscopy, we observed that the co-localization of cofilin-1 and F-actin was slightly influenced by leptin. In summary, the present study demonstrates an impact of a physiological leptin stimulation on the filopodia length, and a time-dependent effect on the co-localization of cofilin and F-actin in NK-92 cells.

Regulatory T Cells Mediate Local Immunosuppression in Lymphedema

Patients who suffer from lymphedema have impaired immunity and, as a result, are at an increased risk for infections. Furthermore, previous studies have shown that lymphadenectomy impairs acquisition of adaptive immune responses and antibody production in response to foreign antigens. Although it is clear that antigen presentation in lymph nodes plays a key role in adaptive immunity, the cellular mechanisms that regulate impaired immune responses in patients with lymphedema or following lymphatic injury remain unknown. We have previously found that axillary lymph node dissection, both clinically and in a mouse model, results in a marked increase in the number of regulatory T cells in the ipsilateral limb. In this study, we focus on the role of regulatory T cells in immunosuppression and show that regulatory T-cell proliferation in tissues distal to site of lymphatic injury contributes to impaired innate and adaptive immune responses. More importantly, using Foxp3-DTR transgenic mice, we show that depletion of regulatory T cells in the setting of lymphatic injury restores these critical immune-mediated responses. These findings provide additional evidence that immune responses following lymphatic injury play a key role in mediating the pathology of lymphedema.

Adipose Tissue Inflammation Induces B Cell Inflammation and Decreases B Cell Function in Aging

Aging is the greatest risk factor for developing chronic diseases. Inflamm-aging, the age-related increase in low-grade chronic inflammation, may be a common link in age-related diseases. This review summarizes recent published data on potential cellular and molecular mechanisms of the age-related increase in inflammation, and how these contribute to decreased humoral immune responses in aged mice and humans. Briefly, we cover how aging and related inflammation decrease antibody responses in mice and humans, and how obesity contributes to the mechanisms for aging through increased inflammation. We also report data in the literature showing adipose tissue infiltration with immune cells and how these cells are recruited and contribute to local and systemic inflammation. We show that several types of immune cells infiltrate the adipose tissue and these include macrophages, neutrophils, NK cells, innate lymphoid cells, eosinophils, T cells, B1, and B2 cells. Our main focus is how the adipose tissue affects immune responses, in particular B cell responses and antibody production. The role of leptin in generating inflammation and decreased B cell responses is also discussed. We report data published by us and by other groups showing that the adipose tissue generates pro-inflammatory B cell subsets which induce pro-inflammatory T cells, promote insulin resistance, and secrete pathogenic autoimmune antibodies.

Clinical Features of Atopic Dermatitis in Adults Are Different according to Onset

Few studies of atopic dermatitis (AD) in adult patients have evaluated differences in clinical features of AD according to onset age. We aimed to characterize the clinical features of AD in adult patients according to age of onset. Subjects with AD outpatient visiting the Department of Dermatology at Kangnam Sacred Heart Hospital were recruited for this study. A dermatologist conducted clinical evaluation, a survey of demographics, and onset of AD-associated signs and symptoms for each participant. Total immunoglobulin E (IgE) was also tested. A total of 280 adult AD patients were enrolled, among which 232 patients (82.86%) showed pre-adult-onset (age < 18 years) and 48 patients (17.14%) had adult-onset (age ≥ 18 years) of AD. There were significant differences between the 2 groups in the area of initial involvement (P = 0.017) and in treatment history (P = 0.010). Interestingly, patients with body mass index (BMI) ≥ 25 showed significantly higher Eczema Area and Severity Index (EASI) scores than did patients with BMI < 25 in the pre-adult-onset adult AD group (P = 0.048). On the other hand, there were no significant differences in sex, family history, BMI, EASI, and total IgE between patients with pre-adult-onset AD and patients with adult-onset AD. Our findings suggest that, even though many common features exist, there are significant differences between the clinical characteristics of pre-adult-onset and adult-onset AD subgroups, in adult patients with AD.

Higher Time-Updated Body Mass Index: Association With Improved CD4+ Cell Recovery on HIV Treatment

BACKGROUND

Prior studies found overweight or obese HIV-infected individuals had greater early CD4 cell recovery on antiretroviral therapy (ART), but the results have been inconsistent. We assessed the longitudinal relationship between body mass index (BMI) and CD4 cell recovery on ART in a large, multisite cohort to identify potential physiologic links between adiposity and CD4 cell expansion.

METHODS

We modeled the relationship of time-updated BMI with CD4 count in patients starting ART from 17 North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) cohorts. The primary analysis used a linear mixed effects model incorporating up to 13 years of data per patient and adjusted for age, sex, race, ART regimen, baseline CD4 count and other covariates. Sensitivity analyses limited the cohort to patients with sustained viral suppression or censored at virologic failure.

RESULTS

Fourteen thousand eighty-four HIV-infected individuals initiating ART contributed data between 1998 and 2010. Time-updated BMI was significantly associated with CD4 cell recovery over time (P < 0.001). After 5 years of ART, the mean CD4 count at a BMI of 30 kg/m was 22% higher than at a BMI of 22 kg/m (606 vs. 498 cells per microliter) and 34% higher at a BMI of 40 kg/m (665 vs. 498 cells per microliter). Results were similar in the sensitivity analyses.

DISCUSSION

Higher BMI is associated with long-term advantages in immune recovery on ART. Although it is unclear if this impacts health outcomes, including balancing the negative health effects of obesity, elucidating the underlying mechanism could identify therapies for patients with suboptimal immune reconstitution.

Changes in body mass index during childhood and risk of various asthma phenotypes: a retrospective analysis

BACKGROUND

It is known that asthma is related to obesity but also to small birthweight. The objective of this study was to clarify this issue by assessing the putative relationship between the changes in corpulence between birth and childhood as assessed by body mass index (BMI) and asthma phenotypes.

METHODS

The following status in corpulence was assessed in 7781 schoolchildren using quartile of BMI at birth and at around 10 (9-11 years): underweight at birth and at around 10, underweight at birth and overweight at around 10, overweight at birth and underweight at around 10, overweight at birth and at around 10, and the reference group constituted by all the other children in whom corpulence changes were not extreme. Determination of asthma phenotypes (allergic, non-allergic, and exercise-induced asthma) was based on a clinical examination including skin prick tests, an exercise challenge test, and a questionnaire.

RESULTS

The risk of allergic asthma was higher in children with persistent underweight, children with persistent overweight, and children becoming markedly more corpulent. In boys, the risk of allergic asthma was significantly higher for the less corpulent children at birth, regardless of whether they remained so or become overweight. In girls, the risk of allergic asthma was significantly higher in those with persistent overweight. There were no significant associations between BMI changes and non-allergic and exercise-induced asthma.

CONCLUSIONS

We observed that some extreme changes in BMI, persistent underweight, and persistent overweight in childhood increased the risk of allergic asthma.

Influence of body mass index on survival in indolent and mantle cell lymphomas: analysis of the StiL NHL1 trial

Obesity is a well-known risk factor for the development of cancer, but its influence on the course of disease is still controversial. We investigated the influence of body mass index (BMI) on overall survival (OS) in 502 patients with indolent non-Hodgkin’s lymphoma or mantle cell lymphoma in a subgroup analysis of the StiL (Study Group Indolent Lymphomas) NHL1 trial. We defined a cut-off of 22.55 kg/m² by ROC calculation and Youden Index analysis and stratified patients into “low BMI” and “high BMI”. Five-year OS was significantly longer in the high BMI group (82.2%) when compared to that of the low BMI group (66.2%) (HR 0.597; 95%CI 0.370–0.963; p = 0.034). BMI was also an independent prognostic factor for OS in multivariate analysis (HR 0.541; 95%CI 0.332–0.883; p = 0.014). Of note, patients had a significantly lower BMI in the presence than patients in the absence of B-symptoms (p = 0.025). BMI significantly impacts on OS in indolent non-Hodgkin’s lymphoma and mantle cell lymphoma, which may be influenced by the effect of B-symptoms on BMI.

Adipokine Contribution to the Pathogenesis of Osteoarthritis

Recent studies have shown that overweight and obesity play an important role in the development of osteoarthritis (OA). However, joint overload is not the only risk factor in this disease. For instance, the presence of OA in non-weight-bearing joints such as the hand suggests that metabolic factors may also contribute to its pathogenesis. Recently, white adipose tissue (WAT) has been recognized not only as an energy reservoir but also as an important secretory organ of adipokines. In this regard, adipokines have been closely associated with obesity and also play an important role in bone and cartilage homeostasis. Furthermore, drugs such as rosuvastatin or rosiglitazone have demonstrated chondroprotective and anti-inflammatory effects in cartilage explants from patients with OA. Thus, it seems that adipokines are important factors linking obesity, adiposity, and inflammation in OA. In this review, we are focused on establishing the physiological mechanisms of adipokines on cartilage homeostasis and evaluating their role in the pathophysiology of OA based on evidence derived from experimental research as well as from clinical-epidemiological studies.

Leptin and adiponectin: pathophysiological role and possible therapeutic target of inflammation in ischemic stroke

Stroke is a multifactorial disease contributing to significant noncommunicable disease burden in developing countries. Risk of stroke is largely a consequence of morbidities of diabetes, obesity, hypertension, and heart diseases. Incidence of stroke is directly proportional to body mass index. Adipose tissue stores energy as well as acts as an active endocrine organ, which secretes numerous humoral factors. Adiponectin and leptin are the commonest adipocytokines and have been invariably linked to the development of coronary heart disease and may be involved in the underlying biological mechanism of stroke. Leptin and adiponectin mediate proatherogenic and antiatherogenic responses, respectively, and hence, determining the plasma or serum levels of leptin and adiponectin alone or in combination may act as a novel prognostic biomarker for inflammation and atherosclerosis in stroke. This review addresses leptin- and adiponectin-mediated inflammatory mechanism in ischemic stroke and their potential as therapeutic targets.

Role of leptin as a link between metabolism and the immune system

Leptin is an adipocyte-derived hormone not only with an important role in the central control of energy metabolism, but also with many pleiotropic effects in different physiological systems. One of these peripheral functions of leptin is a regulatory role in the interplay between energy metabolism and the immune system, being a cornerstone of the new field of immunometabolism. Leptin receptor is expressed throughout the immune system and the regulatory effects of leptin include cells from both the innate and adaptive immune system. Leptin is one of the adipokines responsible for the inflammatory state found in obesity that predisposes not only to type 2 diabetes, metabolic syndrome and cardiovascular disease, but also to autoimmune and allergic diseases. Leptin is an important mediator of the immunosuppressive state in undernutrition status. Placenta is the second source of leptin and it may play a role in the immunomodulation during pregnancy. Finally, recent work has pointed to the participation of leptin and leptin receptor in the pathophysiology of inflammation in oral biology. Therefore, leptin and leptin receptor should be considered for investigation as a marker of inflammation and immune activation in the frontier of innate-adaptive system, and as possible targets for intervention in the immunometabolic mediated pathophysiology.

Leptin receptor expression during the progression of endometrial carcinoma is correlated with estrogen and progesterone receptors

INTRODUCTION

The hormone leptin, which is produced in the adipose tissue, may influence tumorigenesis directly via its receptor (Ob-R). Thus, a role for Ob-R in endometrial carcinogenesis has been proposed. However, most studies neither included samples of the entire histological progression of endometrial carcinoma nor examined Ob-R jointly with the estrogen and progesterone receptors (ER and PR, respectively).

MATERIAL AND METHODS

To determine the fluctuations of Ob-R, ER, and PR during the histological progression of endometrial carcinoma, we assessed their expression via immunohistochemistry (IHC) in six histological types of endometrium (proliferative, secretory, nonatypical and atypical hyperplasia, and endometrioid and nonendometrioid endometrial carcinoma), in which we performed histopathological and digital scoring for the quantification of receptors.

RESULTS

We found that Ob-R expression was positively correlated with that of ER and PR (r = 1, p < 0.001; r = 0.943, p < 0.005, respectively), and there was a significant difference in Ob-R expression among proliferative normal endometrium, hyperplasias, and carcinomas, according to their relative digitally scored Ob-R expression (p < 0.001). In addition, we observed that Ob-R expression in the secretory endometrium was more similar to that of carcinomas than to its proliferative counterpart.

CONCLUSIONS

These results indicate that Ob-R expression fluctuates during endometrial carcinogenesis in correlation with ER and PR, suggesting that Ob-R expression in vivo is highly dependent on estrogen and progesterone activities in the endometrium and on its ER and PR status, as suggested previously by in vitro studies.

Nutritional effects on T-cell immunometabolism

T cells are highly influenced by nutrient uptake from their environment, and changes in overall nutritional status, such as malnutrition or obesity, can result in altered T-cell metabolism and behavior. In states of severe malnutrition or starvation, T-cell survival, proliferation, and inflammatory cytokine production are all decreased, as is T-cell glucose uptake and metabolism. The altered T-cell function and metabolism seen in malnutrition is associated with altered adipokine levels, most particularly decreased leptin. Circulating leptin levels are low in malnutrition, and leptin has been shown to be a key link between nutrition and immunity. The current view is that leptin signaling is required to upregulate activated T-cell glucose metabolism and thereby fuel T-cell activation. In the setting of obesity, T cells have been found to have a key role in promoting the recruitment of inflammatory macrophages to adipose depots along with the production of inflammatory cytokines that promote the development of insulin resistance leading to diabetes. Deletion of T cells, key T-cell transcription factors, or pro-inflammatory T-cell cytokines prevents insulin resistance in obesity and underscores the importance of T cells in obesity-associated inflammation and metabolic disease. Altogether, T cells have a critical role in nutritional immunometabolism.

Lymph Node Transplantation Decreases Swelling and Restores Immune Responses in a Transgenic Model of Lymphedema

INTRODUCTION

Secondary lymphedema is a common complication of cancer treatment and recent studies have demonstrated that lymph node transplantation (LNT) can decrease swelling, as well as the incidence of infections. However, although these results are exciting, the mechanisms by which LNT improves these pathologic findings of lymphedema remain unknown. Using a transgenic mouse model of lymphedema, this study sought to analyze the effect of LNT on lymphatic regeneration and T cell-mediated immune responses.

METHODS

We used a mouse model in which the expression of the human diphtheria toxin receptor is driven by the FLT4 promoter to enable the local ablation of the lymphatic system through subdermal hindlimb diphtheria toxin injections. Popliteal lymph node dissection was subsequently performed after a two-week recovery period, followed by either orthotopic LNT or sham surgery after an additional two weeks. Hindlimb swelling, lymphatic vessel regeneration, immune cell trafficking, and T cell-mediated immune responses were analyzed 10 weeks later.

RESULTS

LNT resulted in a marked decrease in hindlimb swelling, fibroadipose tissue deposition, and decreased accumulation of perilymphatic inflammatory cells, as compared to controls. In addition, LNT induced a marked lymphangiogenic response in both capillary and collecting lymphatic vessels. Interestingly, the resultant regenerated lymphatics were abnormal in appearance on lymphangiography, but LNT also led to a notable increase in dendritic cell trafficking from the periphery to the inguinal lymph nodes and improved adaptive immune responses.

CONCLUSIONS

LNT decreases pathological changes of lymphedema and was shown to potently induce lymphangiogenesis. Lymphatic vessels induced by LNT were abnormal in appearance, but were functional and able to transport antigen-presenting cells. Animals treated with LNT have an increased ability to mount T cell-mediated immune responses when sensitized to antigens in the affected hindlimb.

Obesity paradox in advanced liver disease: obesity is associated with lower mortality in hospitalized patients with cirrhosis

BACKGROUND & AIMS

To investigate how obesity impacts inpatient mortality, length of stay (LOS) and costs in patients with cirrhosis. Obesity is a growing epidemic associated with multiple co-morbidities, increased morbidity, and a significant economic burden on healthcare. Despite the overall harmful impact of obesity, the 'obesity paradox' has been described as decreased mortality among obese vs non-obese patients in various chronic medical conditions.

METHODS

Analysis of the Nationwide Inpatient Sample (NIS) for 2012, which contains data from 44 states and 4378 hospitals. Data from all cases with primary, secondary or tertiary discharge diagnosis of cirrhosis identified by International Classification of Diseases-9 code 571.2, 571.5 571.6 were included. Primary outcomes included inpatient mortality, LOS, and hospital charges. Obesity as a predictor of mortality was defined by a predetermined obesity co-morbidity variable.

RESULTS

A total of 32,605 patients were included. Crude mortality was lower for obese cirrhotic patients (2.7% vs 3.5%, P = 0.02) than for non-obese cirrhotic patients. In contrast, median LOS was longer (4 vs 3 days, P < 0.001) and median hospital charges were higher for obese cirrhotic patients ($26 803 vs $23 447, P < 0.001) In multivariate logistic regression, obesity was associated with a lower risk of inpatient mortality (OR=0.73, 95%CI: 0.55-0.95, P = 0.02).

CONCLUSIONS

In the acute care setting, obese patients with cirrhosis have lower mortality than non-obese patients with cirrhosis, longer hospitalizations and higher healthcare cost, providing new evidence for the obesity paradox in cirrhosis. Obese cirrhotic patients are more likely to have enhanced nutritional reserve which may play a role in survival during acute illness.

Multiple Sclerosis and Obesity: Possible Roles of Adipokines

Multiple Sclerosis (MS) is an autoimmune disorder of the Central Nervous System that has been associated with several environmental factors, such as diet and obesity. The possible link between MS and obesity has become more interesting in recent years since the discovery of the remarkable properties of adipose tissue. Once MS is initiated, obesity can contribute to increased disease severity by negatively influencing disease progress and treatment response, but, also, obesity in early life is highly relevant as a susceptibility factor and causally related risk for late MS development. The aim of this review was to discuss recent evidence about the link between obesity, as a chronic inflammatory state, and the pathogenesis of MS as a chronic autoimmune and inflammatory disease. First, we describe the main cells involved in MS pathogenesis, both from neural tissue and from the immune system, and including a new participant, the adipocyte, focusing on their roles in MS. Second, we concentrate on the role of several adipokines that are able to participate in the mediation of the immune response in MS and on the possible cross talk between the latter. Finally, we explore recent therapy that involves the transplantation of adipocyte precursor cells for the treatment of MS.

Leptin-Induced JAK/STAT Signaling and Cancer Growth

Growth factor and cytokine signaling can influence the development of several cancer types. One of the key players in the development of cancer is the Janus kinas (JAK) signal transducer of activators of transcription (STAT) signaling pathway. The majority of growth factors and cytokine interactions with their membrane-bound receptors trigger JAK-STAT activation. The influential relationship between obesity and cancer is a fact. However, there is a complex sequence of events contributing to the regulation of this mechanism to promote tumor growth, yet to be fully elucidated. The JAK-STAT pathway is influenced by obesity-associated changes that have been shown to impact cancer growth and progression. This intricate process is highly regulated by a vast array of adipokines and cytokines that exert their pleiotropic effects on cancer cells to enhance metastasis to distant target sites. Leptin is a cytokine, or more precise, an adipokine secreted mainly by adipose tissue that requires JAK-STAT activation to exert its biological functions. Leptin is the central regulator of energy balance and appetite. Leptin binding to its receptor OB-R in turn activates JAK-STAT, which induces proliferation, angiogenesis, and anti-apoptotic events in normal cells and malignant cells expressing the receptor. Leptin also induces crosstalk with Notch and IL-1 (NILCO), which involves other angiogenic factors promoting tumor growth. Therefore, the existence of multiple novel classes of therapeutics that target the JAK/STAT pathway has significant clinical implications. Then, the identification of the signaling networks and factors that regulate the obesity-cancer link to which potential pharmacologic interventions can be implemented to inhibit tumor growth and metastasis. In this review, we will discuss the specific relationship between leptin-JAK-STAT signaling and cancer.

Differential Role of Leptin as an Immunomodulator in Controlling Visceral Leishmaniasis in Normal and Leptin-Deficient Mice

Visceral leishmaniasis (VL) is caused by the protozoan parasite Leishmania donovani. There are no vaccines and available drugs against leishmaniasis are toxic. Immunomodulators that specifically boost the anti-microbial activities of the immune cells could alleviate several of these limitations. Therefore, finding novel immunomodulators for VL therapy is a pressing need. This study is aimed to evaluate the immunomodulatory role of leptin, an adipocyte-derived hormone capable of regulating the immune response, in L. donovani-infected mice. We observed that recombinant leptin treatment reduced splenic parasite burden compared with non-treated infected normal mice. Decrease in parasite burden correlated with an induction of innate immune response in antigen-presenting cells that showed an increase in nitric oxide, enhanced pro-inflammatory cytokine (interferon gamma [IFNγ], interleukin12 [IL]12, and IL1β) response in the splenocytes, indicating host-protecting Th1 response mediated by leptin. Moreover, in infected normal mice, leptin treatment induced IFNγ production from both CD4⁺ and CD8⁺ T cells, compared with non-treated infected mice. Alternatively, leptin-deficient (Ob/Ob) mice had higher splenic and liver parasite burden compared with the infected normal mice. However, leptin treatment failed to reduce the splenic parasite burden and improve a host-protective cytokine response in these mice. In addition, in contrast to dendritic cells (DCs) from a normal mouse, Ob/Ob mouse–derived DCs showed a defect in the induction of innate immune response on Leishmania infection that could not be reversed by leptin treatment. Therefore, our findings reveal that leptin has a differential immunomodulatory effect in controlling VL in normal and Ob/Ob mice.

The cellular composition of the human immune system is shaped by age and cohabitation

Detailed population-level description of the human immune system has recently become achievable. We used a 'systems-level' approach to establish a resource of cellular immune profiles of 670 healthy individuals. We report a high level of interindividual variation, with low longitudinal variation, at the level of cellular subset composition of the immune system. Despite the profound effects of antigen exposure on individual antigen-specific clones, the cellular subset structure proved highly elastic, with transient vaccination-induced changes followed by a return to the individual's unique baseline. Notably, the largest influence on immunological variation identified was cohabitation, with 50% less immunological variation between individuals who share an environment (as parents) than between people in the wider population. These results identify local environmental conditions as a key factor in shaping the human immune system.

Adipokine-myokine-hepatokine compartment-system in mothers and children: An explorative study

Objective

Maternal lifestyle during pregnancy has an effect of gestational development and neonatal outcome. Overweight gravidas and gravidas with excessive weight gain have an increased risk of gestational complications and neonatal metabolic disorder. The underlying mechanisms are still under discussion, but the hormonally active fat mass and its biomarkers, adipocytokines, may play a key role by potentially having a direct impact on the metabolic homeostasis of the system in concert with other biomarkers like hepatokines and myokines. Up to now little is known in terms of lifestyle habits and their effect on this complex model on maternal and fetal outcome. Therefore, we aim to investigate the influence of maternal lifestyle clusters during pregnancy on the maternal and fetal biomarkers of compartments, specifically those implying maternal fat and muscle mass, maternal liver and the placenta and who are associated with maternal body composition and birth weight.

Methods

In this exploratory pilot study at least 100 singleton pregnancies and their newborns will be included. The women will undergo assessments of anthropometric measurements, venous blood samples will be drawn and physical activity and nutritional status will be collected through questionnaires. Newborns will undergo assessments of anthropometric measurements, umbilical cord samples will be drawn and birth outcomes will be evaluated. We will measure adipokines, myokines and hepatokines and relate them to maternal lifestyle clusters and fetal outcome.

Conclusion

Our study will be the first to examine the relationship between maternal body composition, birth weight and potential biomarkers based on an innovative compartment model.

Maternal obesity associated with increase in natural killer T cells and CD8+ regulatory T cells in cord blood units

BACKGROUND

One of the major limitations of umbilical cord blood (UCB) as hematopoietic stem cell source is its restricted cell number. In mothers who are candidates for stem cell donation, there are variables that affect the quantity and quality of UCB units. The aim of this study was to determine if obstetric, maternal, and fetal factors modify the number of lymphocyte subsets in UCB units.

STUDY DESIGN AND METHODS

This was a prospective, observational study. In UCB units, the numbers of CD34, NK, NKT, iNKT, Type 1 dendritic cells (DCs), Type 2 DCs, T γδ, T CD4+, T CD8+ lymphocytes, CD4+CD25+FoxP3+, and CD8+CD25+FoxP3+ T regulatory (Treg) cells were quantified by flow cytometry.

RESULTS

Fifty-four UCB units were included; the donors' mean weight was 75 kg (range, 52 to 102 kg) and they had a mean body mass index (BMI) of 30 kg/m(2) (range 22 to 40 kg/m(2) ), of which 12 (22%) had a normal BMI, 14 (26%) were overweight, and 28 (52%) were obese. The mean number of CD34+ cells was 4.45 × 10(6) (range, 0.7 × 10(6) to 20.5 × 10(6) ). The number of NKT, CD3+, CD4+, CD8+, and CD8+CD25+FoxP3+ Treg cells was significantly higher in overweight or obese mothers; CD34+ cells were decreased in the same group. The number of iNKT and CD34+ cells was decreased in newborns weighing above the average.

CONCLUSIONS

Maternal factors such as BMI, and fetal factors such as weight at birth, should be added to the selection criteria of UCB donors.

Leptin induces the phagocytosis and protective immune response in Leishmania donovani infected THP-1 cell line and human PBMCs

Visceral leishmaniasis (VL) is an infectious disease responsible for several deaths in malnourished children due to impaired cell-mediated immunity, which is accompanied by low circulating leptin levels. The cytokine function of leptin is implicated for several immune regulation activities such as hematopoiesis, angiogenesis, innate and adaptive immunity. Its deficiency associated with polarization of Th2 response, which coincides with VL pathogenesis. To determine the cytokine role of leptin in case of experimental VL, we tested the leptin associated Th1/Th2 type cytokine profile at mRNA level from Leishmania donovani infected human monocytic leukemia cell line (THP-1) and peripheral blood mononuclear cells (PBMCs). We also tested the effect of leptin on macrophages activation (viz. studying the phosphorylation of signaling moieties), phagocytic activity and intracellular reactive oxygen species (ROS) production during infection. We observed that leptin induced Th1 specific response by upregulation of IL-1α, IL-1β, IL-8 and TNF-α in THP-1 and IFN-γ, IL-12 and IL-2 in PBMCs. We also observed the downregulation of Th2 type cytokine i.e. IL-10 in THP-1 and unaltered expression of cytokines i.e. TGF-β, IL-10 and IL-4 in PBMCs. In addition, leptin stimulates the macrophages by inducing phosphorylation of Erk1/2 and Akt which are usually dephosphorylated in L. donovani infection. In concordance, leptin also induces the macrophage phagocytic activity by enhancing the intracellular ROS generation which helps in phagolysosome formation and oxidative killing of the parasite. In compilation, leptin is able to maintain the defensive environment against L. donovani infection through the classical macrophage activity.

Leptin Deficiency Shifts Mast Cells toward Anti-Inflammatory Actions and Protects Mice from Obesity and Diabetes by Polarizing M2 Macrophages

Mast cells (MCs) contribute to the pathogenesis of obesity and diabetes. This study demonstrates that leptin deficiency slants MCs toward anti-inflammatory functions. MCs in the white adipose tissue (WAT) of lean humans and mice express negligible leptin. Adoptive transfer of leptin-deficient MCs expanded ex vivo mitigates diet-induced and pre-established obesity and diabetes in mice. Mechanistic studies show that leptin-deficient MCs polarize macrophages from M1 to M2 functions because of impaired cell signaling and an altered balance between pro- and anti-inflammatory cytokines, but do not affect T cell differentiation. Rampant body weight gain in ob/ob mice, a strain that lacks leptin, associates with reduced MC content in WAT. In ob/ob mice, genetic depletion of MCs exacerbates obesity and diabetes, and repopulation of ex vivo expanded ob/ob MCs ameliorates these diseases.

Effect of Diet and Exercise on the Peripheral Immune System in Young Balb/c Mice

Although diet and exercise clearly have an influence on immune function, studies are scarce on the effect caused by exercise and the consumption of a carbohydrate-rich or fat-rich diet on the peripheral immune system. The aim of the present study was to evaluate the effect of exercise and the two aforementioned unbalanced diets on young Balb/c mice, especially in relation to BMI, the level of glucose, and the percentage of lymphocyte subpopulations in peripheral blood. The changes found were then related to the synthesis of leptin and adiponectin as well as the production of oxidative stress. The increase in BMI found with the carbohydrate-rich and fat-rich diets showed correlation with the levels of leptin and adiponectin. An increase in leptin and a decrease in adiponectin directly correlated with an increase in total lymphocytes and CD4+ cells and with a decrease in B cells. The increase in leptin also correlated with an increase in CD8+ cells. Glycemia and oxidative stress increased with the two unbalanced diets, negatively affecting the proliferation of total lymphocytes and the percentage of B cells, apparently by causing alterations in proteins through carbonylation. These alterations caused by an unbalanced diet were not modified by moderate exercise.

Mechanical stretch-induced vascular hypertrophy occurs through modulation of leptin synthesis-mediated ROS formation and GATA-4 nuclear translocation

Background: Obesity and hypertension are associated with increased leptin production contributing to cardiovascular remodeling. Mechanisms involving mechanical stretch-induced leptin production and the cross talk between signaling pathways leading to vascular remodeling have not been fully elucidated.

Methods and Results: Rat portal vein (RPV) organ culture was used to investigate the effect of mechanical stretch on leptin protein expression in vascular smooth muscle cells (VSMCs). Moreover, the involvement of reactive oxygen species (ROS), the RhoA/ROCK pathway, actin cytoskeleton dynamics and the transcriptional factor GATA-4 activation in mechanical stretch-induced vascular remodeling were investigated. Stretching the RPV for 1 or 24 h significantly increased leptin protein level and ROS formation in VSMCs, which was prevented by 1 h pretreatment with the ROCK inhibitor Y-27632 and the actin cytoskeleton depolymerization agent cytochalasin D. Moreover, Western blotting and immunohistochemistry revealed that mechanical stretch or treatment with 3.1 nmol/L leptin for 24 h significantly increased actin polymerization, as reflected by an increase in the F-actin to G-actin ratio. Increases in blood vessels’ wet weight and [³H]-leucine incorporation following a 24 h treatment with conditioned media from cultured stretched RPVs indicated RPV hypertrophy. This effect was prevented by 1 h pretreatment with anti-leptin antibody, indicating leptin’s crucial role in promoting VSMC hypertrophy. As an index of GATA-4 activation, GATA-4 nuclear translocation was assessed by immunohistochemistry method. Pretreating VSMC with leptin for 1 h significantly activated GATA-4 nuclear translocation, which was potently attenuated by the NADPH oxidase inhibitor apocynin, Y-27632, and cytochalasin D.

Conclusion: Our results demonstrate that ROS formation, RhoA/ROCK pathway, and GATA-4 activation play a pivotal role in mechanical stretch-induced leptin synthesis leading to VSMC remodeling.

Leptin augments protective immune responses in murine macrophages and enhances potential of miltefosine against experimental visceral leishmaniasis

Adverse side effects and drug resistance issues are the two most important drawbacks which influence the widespread use of existing antileishmanial drugs. Use of immune stimulating agent with standard antileishmanial might be helpful to minimize the toxic effect of drug, shorten the dose regimen and delay the emergence of resistance. In the present study, we explored the in vitro immunomodulatory potential of an immunomodulator, leptin with lower concentration of standard drug, miltefosine. The level of Th1/Th2 cytokines, production of nitric oxide and reactive oxygen species and phagocytic activity was assessed by ELISA, Griess reaction and flow cytometric analysis, respectively. Leptin at a concentration of 15μg/mL showed heightened level of Th1 cytokines and nitric oxide generation from murine macrophages (J-774A.1 cells). Leptin (15μg/mL) also reduces the effective concentration of miltefosine by 2-folds from 7.5μM to 3.7μM. When given in conjunction with lower concentration of miltefosine (4μM), leptin (15μg/mL) significantly (***p<0.001) elevated the level of IL-12 (7.7 fold), TNF-α (8.1 fold) and nitric oxide (6.6 fold) along with markedly (***p<0.001) suppressed level of IL-10 and TGF-β when compared with untreated infected macrophages. Leptin plus miltefosine also induces the phagocytic ability (**p<0.01) of macrophages in comparison to leptin alone and miltefosine alone treated groups. These finding illustrate that leptin activates host macrophages to generate protective immune response for the successful elimination of Leishmania parasite at lower concentration of miltefosine and has potential for further exploration in experimental animal model of visceral leishmaniasis (VL).

Association Between Obesity, Abdominal Obesity, and Adiposity and the Prevalence of Atopic Dermatitis in Young Korean Adults: the Korea National Health and Nutrition Examination Survey 2008-2010

PURPOSE

Whether obesity is a risk factor for atopic dermatitis (AD) remains unclear. The aim of the present study was to investigate the association between obesity and AD in Korean young adults.

METHODS

We included nationally representative data of 5,202 Korean adults aged 19-40 years, obtained from the cross-sectional Korea National Health and Nutrition Examination Survey 2008-2010.

RESULTS

Single (unmarried) status was more frequently observed in AD patients (male, [P=0.0002] and female, [P<0.0001]). AD prevalence exhibited a U-shape trend in relation to body mass index (BMI), waist circumference (WC), and total body fat (BF) percentage, especially in young adult women. Women with BMI ≥25 kg/m², WC ≥80 cm, and highest quartile (Q4) of total BF percentage had the highest prevalence of AD. The odds ratio (OR) for participants with both BMI ≥25 kg/m² and WC ≥80 cm was 3.29 (95% confidence interval [CI] 1.71-3.55); therefore, having both general and abdominal obesity was considered a prominent risk factor for AD in young women. After adjustment for confounding factors, including age, smoking, alcohol drinking, exercise, vitamin D, income level, and single status, high BMI (≥30 kg/m²) (OR=4.08, 95% CI: 1.53-10.93), high WC (≥80 cm) (OR=2.05, 95% CI: 1.07-3.94), and high BF percentage (Q4) (OR=2.10, 95% CI: 1.24-3.57) were shown to be significantly associated with AD in young adult women.

CONCLUSIONS

In this large-scale nation-wide study of Korean adults, obesity was positively related to the presence of AD in women. Our findings suggest that weight management may help prevent AD.

Screening for Differentially Expressed Proteins Relevant to the Differential Diagnosis of Sarcoidosis and Tuberculosis

Background

In this study, we sought to identify differentially expressed proteins in the serum of patients with sarcoidosis or tuberculosis and to evaluate these proteins as markers for the differential diagnosis of sarcoidosis and sputum-negative tuberculosis.

Methods

Using protein microarrays, we identified 3 proteins exhibiting differential expression between patients with sarcoidosis and tuberculosis. Elevated expression of these proteins was verified using the enzyme-linked immunosorbent assay (ELISA) and was further confirmed by immunohistochemistry. Receiver operating characteristic (ROC) curve, logistic regression analysis, parallel, and serial tests were used to evaluate the diagnostic efficacy of the proteins.

Results

Intercellular Adhesion Molecule 1(ICAM-1) and leptin were screened for differentially expressed proteins relevant to sarcoidosis and tuberculosis. Using ROC curves, we found that ICAM-1 (cutoff value: 57740 pg/mL) had an area under the curve (AUC), sensitivity, and specificity of 0.718, 62.3%, and 79.5% respectively, while leptin (cutoff value: 1193.186 pg/mL) had an AUC, sensitivity, and specificity of 0.763, 88.3%, and 65.8%, respectively. Logistic regression analysis revealed that the AUC, sensitivity, and specificity of combined leptin and ICAM-1 were 0.787, 89.6%, and 65.8%, respectively, while those of combined leptin, ICAM-1, and body mass index (BMI) were 0.837, 90.9%, and 64.4%, respectively, which had the greatest diagnostic value. Parallel and serial tests indicated that the BMI-leptin parallel with the ICAM-1 serial was the best diagnostic method, achieving a sensitivity and specificity of 86.5% and 73.1%, respectively. Thus, our results identified elevated expression of ICAM-1 and leptin in serum and granulomas of sarcoidosis patients.

Conclusions

ICAM-1 and leptin were found to be potential markers for the diagnosis of sarcoidosis and differential diagnosis of sarcoidosis and sputum-negative tuberculosis.

Decelerated vascularization in tissue-engineered constructs in association with diabetes mellitus in vivo

AIMS

Rapid blood vessel ingrowth in transplanted tissue engineering constructs is the key factor for successful incorporation, but many potential patients who may use engineered tissues suffer from widespread diseases that limit the capacity of neovascularization (e.g. diabetes). Thus, in vivo vascularization analyses of tissue-engineered constructs in angiogenically affected organisms are required.

METHODS

We therefore investigated the in vivo incorporation of collagen-coated and cell-seeded poly-L-lactide-co-glycolide scaffolds in diabetic B6.BKS(D)-Lepr(db)/J mice using repetitive intravital fluorescence microscopy over a time period of two weeks. For this purpose, scaffolds were seeded with osteoblast-like or bone marrow mesenchymal stem cells and implanted into the dorsal skinfold chambers of diabetic and non-diabetic (C57BL/6) mice.

RESULTS

Apart from slightly increased inflammatory parameters, diabetic mice showed significantly reduced capillary densities compared with non-diabetic animals from day 6 onward. In line with previous studies, more densely meshed microvascular networks were demonstrated in cell-seeded than in collagen-coated scaffolds from day 6 onward within the single groups (diabetic and control).

CONCLUSIONS

A large number of patients who suffer from systemic diseases that affect angiogenesis would profit from tissue engineering. Therefore, the challenge for the clinical introduction of tissue-engineered constructs will be to overcome the decreased angiogenesis in diabetic organisms.

Adenovirus 36 and Obesity: An Overview

There is an epidemic of obesity starting about 1980 in both developed and undeveloped countries definitely associated with multiple etiologies. About 670 million people worldwide are obese. The incidence of obesity has increased in all age groups, including children. Obesity causes numerous diseases and the interaction between genetic, metabolic, social, cultural and environmental factors are possible cofactors for the development of obesity. Evidence emerging over the last 20 years supports the hypothesis that viral infections may be associated with obesity in animals and humans. The most widely studied infectious agent possibly linked to obesity is adenovirus 36 (Adv36). Adv36 causes obesity in animals. In humans, Adv36 associates with obesity both in adults and children and the prevalence of Adv36 increases in relation to the body mass index. In vivo and in vitro studies have shown that the viral E4orf1 protein (early region 4 open reading frame 1, Adv) mediates the Adv36 effect including its adipogenic potential. The Adv36 infection should therefore be considered as a possible risk factor for obesity and could be a potential new therapeutic target in addition to an original way to understand the worldwide rise of the epidemic of obesity. Here, the data indicating a possible link between viral infection and obesity with a particular emphasis to the Adv36 will be reviewed.

Menopause, obesity and inflammation: interactive risk factors for Alzheimer's disease

Alzheimer’s disease (AD) is a multifactorial neurodegenerative disorder, the development of which is regulated by several environmental and genetic risk factors. Two factors theorized to contribute to the initiation and/or progression of AD pathogenesis are age-related increases in inflammation and obesity. These factors may be particularly problematic in women. The onset of menopause in mid-life elevates the vulnerability of women to AD, an increased risk that is likely associated with the depletion of estrogens. Menopause is also linked with an abundance of additional changes, including increased central adiposity and inflammation. Here, we review the current literature to explore the interactions between obesity, inflammation, menopause and AD.

Expression and immunohistochemical localization of leptin in human periapical granulomas

BACKGROUND

Leptin, initially described as an adipocyte-derived hormone to regulate weight control, is expressed in normal and inflamed human dental pulp, being up-regulated during pulp experimental inflammation. Leptin receptor (LER) has been identified in human periapical granulomas. The aim of this study was to analyze and characterize the expression of leptin in human periapical granulomas.

MATERIAL AND METHODS

Fifteen periapical inflammatory lesions were obtained from extracted human teeth and teeth which underwent periapical surgery. After their morphological categorization as periapical granulomas and gradation of the inflammatory infiltrate, they were examined by immunohistochemistry using human leptin policlonal antibodies. Leptin mRNA expression was also determined by quantitative real-time PCR (qRT-PCR) and the amount of leptin protein was analyzed by immunoblot.

RESULTS

All periapical lesions exhibited the characteristic of chronic granulomatous inflammatory process with inflammatory infiltrate grade III. Leptin+ cells were detected in 13 periapical granulomas (86.6%). The median number of Leptin+ cells in periapical granulomas was 1.70 (0.00-7.4). Amongst the inflammatory cells in the periapical granulomas, only macrophages were reactive to leptin antibodies. Western blot analysis revealed the presence in all samples of a protein with apparent molecular weight of approximately 16 kDa, corresponding to the estimated molecular weights of leptin. The expression of leptin mRNA was confirmed by qRT-PCR analysis and the size of the amplified fragment (296 bp for leptin and 194 bp for cyclophilin) was assessed by agarose gel electrophoresis.

CONCLUSIONS

For the first time, it has been demonstrated that human periapical granuloma expresses the adipokine leptin.

Association Between Gingival Crevicular Fluid Leptin Levels and Periodontal Status - A Biochemical Study on Indian Patients

AIM

The present study was carried out to evaluate and compare the gingival crevicular fluid (GCF) concentrations of leptin in periodontally healthy and diseased subjects, to compare GCF leptin levels with respect to Body Mass Index (BMI) among the study groups and essentially to obtain an insight into leptin's possible role in the initiation and progression of periodontal disease.

MATERIALS AND METHODS

A total of 60 subjects; both males and females, based on their body mass index were selected for the study. They were categorized into three groups of 20 subjects each, based on their periodontal status, as follows: Group I (clinically healthy periodontium); Group II (gingivitis); Group III (chronic periodontitis). GCF samples of 1 μl were collected extra-crevicularly using black color-coded 1-5 μl calibrated volumetric microcapillary pipettes from one site in each person, and samples were analyzed for leptin using a commercially available ELISA kit.

RESULTS

The concentration of leptin in GCF of patients in Group I (2272.25 pg/mL) was statistically higher (p < 0.001) than in those of Group II (1421.86 pg/mL) and Group III (1160.67 pg/mL). No statistically significant difference was found when comparing the mean values of leptin between BMI groups in each study group.

CONCLUSION

As periodontal disease progressed, there was a substantial decrease in the gingival crevicular fluid leptin concentration. This suggests a protective role of leptin with regard to periodontal health.

Wasting and Stunting—Similarities and Differences: Policy and Programmatic Implications

Wasting and stunting are often presented as two separate forms of malnutrition requiring different interventions for prevention and/or treatment. These two forms of malnutrition, however, are closely related and often occur together in the same populations and often in the same children. Wasting and stunting are both associated with increased mortality, especially when both are present in the same child. A better understanding of the pathophysiology of these two different forms of malnutrition is needed to design efficient programs. A greatly reduced muscle mass is characteristic of severe wasting, but there is indirect evidence that it also occurs in stunting. A reduced muscle mass increases the risk of death during infections and also in many other different pathological situations. Reduced muscle mass may represent a common mechanism linking wasting and stunting with increased mortality. This suggests that to decrease malnutrition-related mortality, interventions should aim at preventing both wasting and stunting, which often share common causes. Also, this suggests that treatment interventions should focus on children who are both wasted and stunted and therefore have the greatest deficits in muscle mass, instead of focusing on one or the other form of malnutrition. Interventions should also focus on young infants and children, who have a low muscle mass in relation to body weight to start with. Using mid-upper-arm circumference (MUAC) to select children in need of treatment may represent a simple way to target young wasted and stunted children efficiently in situations where these two conditions are present. Wasting is also associated with decreased fat mass. A decreased fat mass is frequent but inconsistent in stunting.

Fat secretes multiple hormones, including leptin, which may have a stimulating effect on the immune system. Depressed immunity resulting from low fat stores may also contribute to the increased mortality observed in wasting. This may represent another common mechanism linking wasting and stunting with increased mortality in situations where stunting is associated with reduced fat mass. Leptin may also have an effect on bone growth. This may explain why wasted children with low fat stores have reduced linear growth when their weight-for-height remains low. It may also explain the frequent association of stunting with previous episodes of wasting. Stunting, however, can occur in the absence of wasting and even in overweight children. Thus, food supplementation should be used with caution in populations where stunting is not associated with wasting and low fat stores.

Natural history and risk factors of atopic dermatitis in children

Atopic dermatitis (AD) is one of the most common inflammatory allergic diseases with pruritic skin lesions particularly in infancy. It is considered to be the first step of atopic march and has variable disease courses. Many children with AD may resolve their AD symptoms with increasing age and may develop respiratory allergies such as asthma and rhinoconjunctivitis at certain ages. Natural course of AD has been supported by many cross-sectional and longitudinal studies in many countries. In general, atopic dermatitis tends to be more severe and persistent in young children, particularly if they have some risk factors including genetic factors. It appears that approximately 40%-70% of childhood AD will get resolved when they reach the age of 6-7 years. However, it is also observed that over half of the children with AD developed respiratory allergy during late childhood.

Metabolic inflammation in inflammatory bowel disease: crosstalk between adipose tissue and bowel

Epidemiological studies show that both the incidence of inflammatory bowel disease (IBD) and the proportion of people with obesity and/or obesity-associated metabolic syndrome increased markedly in developed countries during the past half century. Obesity is also associated with the development of more active IBD and requirement for hospitalization and with a decrease in the time span between diagnosis and surgery. Patients with IBD, especially Crohn's disease, present fat-wrapping or "creeping fat," which corresponds to ectopic adipose tissue extending from the mesenteric attachment and covering the majority of the small and large intestinal surface. Mesenteric adipose tissue in patients with IBD presents several morphological and functional alterations, e.g., it is more infiltrated with immune cells such as macrophages and T cells. All these lines of evidence clearly show an association between obesity, adipose tissue, and functional bowel disorders. In this review, we will show that the mesenteric adipose tissue and creeping fat are not innocent by standers but actively contribute to the intestinal and systemic inflammatory responses in patients with IBD. More specifically, we will review evidence showing that adipose tissue in IBD is associated with major alterations in the secretion of cytokines and adipokines involved in inflammatory process, in adipose tissue mesenchymal stem cells and adipogenesis, and in the interaction between adipose tissue and other intestinal components (immune, lymphatic, neuroendocrine, and intestinal epithelial systems). Collectively, these studies underline the importance of adipose tissue for the identification of novel therapeutic approaches for IBD.

Altered NK cell function in obese healthy humans

Background

Obesity is associated with an elevated risk for several types of cancer and thus a major health hazard. However, the mechanism between overweight and cancer susceptibility is still elusive. Leptin, mainly produced by adipocytes links food intake and energy expenditure. In addition, recent studies have shown an immunomodulatory impact of leptin on NK cells. The purpose of the present study was to investigate whether leptin stimulation of NK cells from obese humans leads to altered functions as compared to NK cells from lean subjects. On the basis of body mass index 20 healthy individuals were classified in two groups: normal weight (<25 kg/m²) and obese (>30 kg/m²). Peripheral blood mononuclear cells (PBMC) were isolated from blood samples. We used flow cytometry to assess differences in phenotype and activity markers (CD107a, CD178 and TRAIL) of PBMCs between both groups. Furthermore, we determined after short-term in vitro leptin stimulation the phosphorylation of JAK2, downstream target of the intracellular signaling cascade of the leptin receptor, by Western Blotting and numbers of NK-cell-tumor-cell-conjugates as well as Granzyme⁺ and IFN-γ⁺ NK cells by flow cytometry. Finally, the proliferative capacity of control and long-term (7 days) leptin-stimulated NK cells was examined.

Results

As opposed to similar NK cell counts, the number of CD3⁺CD56⁺ cells was significantly lower in obese compared to lean subjects. Human NK cells express the leptin receptor (Ob-R). For further determination of Ob-R, intracellular target proteins of PBMCs were investigated by Western Blotting. Phosphorylation of JAK2 was lower in obese as compared to normal weight subjects. Furthermore, significantly lower levels of TNF-related apoptosis-inducing ligand (TRAIL) as an NK cell functional marker in obese subjects were found. In vitro leptin stimulation resulted in a higher production of interferon-γ in NK cells of normal weight subjects. Interestingly, long-term leptin stimulation had no significant influence on numbers of proliferating NK cells.

Conclusions

NK cells from obese healthy humans show functional deficits and altered responses after in vitro leptin challenge.