JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 8 2003
Schelte J. Fokkema
Abstract Background: As some residual inflammation may remain after periodontal therapy, the present pilot study investigated the long-term effect of full-mouth tooth extraction therapy on the responsiveness of peripheral blood monocytes in a case with generalized terminal adult periodontitis. Methods: Before and 3, 9, 20 and 32 months after therapy, venous blood was collected. Total and differential white blood cell counts were determined and whole blood cell cultures (WBCC) were incubated with lipopolysaccharide (LPS) to stimulate the production of inflammatory mediators by monocytes. Results: After full-mouth tooth extraction, the numbers of total peripheral white blood cells and neutrophils decreased over time. The release of the chemokines interleukin (IL)-8 and macrophage chemoattractant protein (MCP)-1 in the cultures decreased twofold over time, whereas no changes were seen for the other studied cytokines, chemokines and prostaglandin E2. Conclusion: On the basis of previous studies and the present case, the high production of IL-8 and MCP-1 by monocytes in LPS-stimulated WBCC from periodontitis patients is most likely acquired, as their levels decrease over time when the periodontal infection is controlled. The possible connection between periodontitis and atherosclerosis through IL-8 and MCP-1 is discussed. Zusammenfassung Hintergrund: Da nach der parodontalen Therapie eine restliche Entzündung zurückbleiben kann, untersucht die vorliegende Studie den Langzeiteffekt einer vollständigen Zahnextraktion auf die Ansprechbarkeit der peripheren Blutmonozyten in einem Fall mit generalisierter unheilbarer Erwachsenen-Parodontitis. Methoden: Vor und 3, 9, 20 und 32 Monaten nach der Therapie wurde venöses Blut gesammelt. Der totale und differenzierte weiße Blutzellgehalt wurden bestimmt, und eine gesamte Blutzellkultur (WBCC) wurde mit Lipopolysaccharid inkubiert, um die Produktion von Entzündungsmediatoren durch Lymphozyten zu stimulieren. Ergebnisse: Nach der vollständigen Zahnextraktion verringerte sich die Zahl der totalen peripheren weißen Blutzellen und der Neutrophilen über die Zeit. Die Freisetzung des Chemokins Interleukin 8 (IL-8) und des Makrophagen chemoattraktanten Proteins (MCP) ,1 in den Kulturen verringerte sich zweifach über die Zeit, während für die anderen beobachteten Cytokine, Chemokine und Prostaglandin E2 keine Veränderungen festgestellt wurden. Schlussfolgerung: Auf der Basis vorheriger Studien und des vorliegenden Falls ist die hohe Produktion von IL-8 und MCP-1 durch Monozyten in LPS stimulierten WBCC von Parodontitis-Patienten sehr wahrscheinlich anzunehmen, da ihr Level über die Zeit abnimmt, wenn die parodontale Infektion kontrolliert ist. Die mögliche Verbindung zwischen Parodontitis und Arteriosklerose durch IL-8 und MCP-1 wird diskutiert. Résumé Contexte: Puisqu'après traitement parodontal, une inflammation résiduelle peut subsister, cette étude se propose de rechercher les effets à long terme de l'extraction complète des dents sur la réponse des monocytes périphériques dans un cas de parodontite de l'adulte terminale généralisée. Méthodes: Des prélèvements sanguins veineux ont été réalisés avant et 3, 9, 20 et 32 mois après traitement. Les comptages totaux et relatifs des cellules blanches sanguines furent déterminés et les cultures complètes de cellules sanguines (WBCC) furent incubées avec du lipopolysaccharide pour stimuler la production des médiateurs de l'inflammation par les monocytes. Résultats: Après l'extraction complète des dents, les nombres de cellules sanguines blanches totales périphériques et des neutrophiles diminuaient au cours du temps. Le relargage des chimiokines interleukine (IL)-8 et protéine chimio-attractante du macrophage (MCP)-1 dans les cultures diminuait deux fois au cours du temps, alors qu'aucun changement n'était observé pour les autres cytokines étudiées, chimiokines et prostaglandine E2. Conclusion: Sur la base d'études préalables, et les résultats issus de ce cas présent, la forte production d'IL-8 et de MCP-1 par les monocytes dans les WBCC stimulés par le LPS chez des patients atteints de parodontite semble être vraisemblablement acquise puisque leurs niveaux diminuent lorsque l'infection parodontale est contrôlée. La relation possible entre parodontite et l'athérosclérose par IL-8 et MCP-1 est discutée. [source]

Clinical outcome and IL-17, IL-23, IL-27 and FOXP3 expression in peripheral blood mononuclear cells of pollen-allergic children during sublingual immunotherapy

PEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 1-Part-II 2010
Kaisa Nieminen
Nieminen K, Valovirta E, Savolainen J. Clinical outcome and IL-17, IL-23, IL-27 and FOXP3 expression in peripheral blood mononuclear cells of pollen-allergic children during sublingual immunotherapy. Pediatr Allergy Immunol 2010: 21: e174,e184. © 2009 John Wiley & Sons A/S Induction of allergen-specific, tolerogenic, IL-10 and/or TGF-,-producing T-regulatory (Treg) cells that express transcription factor FOXP3 is considered as one of the key mechanisms of allergen-specific immunotherapy. However, little is known of the induction of FOXP3 expression in children during sublingual immunotherapy (SLIT). Recently, also, a novel subgroup of T-helper (Th) cells, the Th17 cells, secreting predominantly IL-17 (IL-17A), was identified. The expressions of IL-17 or the Th17-regulating cytokines IL-23 and IL-27 during SLIT are currently completely unexplored. This randomized, placebo-controlled dose-response study was performed to analyze the effects of SLIT on FOXP3, IL-17, IL-23, and IL-27 expressions in peripheral blood mononuclear cells (PBMC) of children with allergic rhinitis and their associations with clinical outcome. Thirty children were included: ten received SLIT with a glycerinated mixture of birch, hazel and alder with a cumulative weekly dose of 24,000 SQ-U, 10 with dose 200,000 SQ-U/wk, and ten received placebo. Cytokine and FOXP3 mRNA expressions in allergen-, purified protein derivative-stimulated and non-stimulated PBMC were determined at 0, 1 and 2 yr of SLIT by real-time RT-PCR (TaqMan®). Symptoms and medications were recorded using diary cards. Allergen-induced IL-17 mRNA expression was significantly increased in the study subjects with elevated combined Symptom Medication Score (SMS) after 2 yr. There was also a significant positive correlation between the allergen-induced IL-17 and SMS in whole study group (r = 0.38, p = 0.039) and especially the 200,000 SQ-U dose-treated group (r = 0.74, p = 0.027) at 2 yr. Allergen-induced FOXP3 mRNA expression was significantly increased in the 200,000 SQ-U dose-treated children after two study years as compared with baseline (p = 0.016) and placebo-treated children (p = 0.028). The changes in FOXP3 mRNA expression positively correlated with IL-10 and TGF-, mRNAs during SLIT in whole study population. Increased allergen-induced IL-17 responses during SLIT are associated with elevated SMS. Increased tolerogenic, allergen-specific Treg responses are also observed in children during SLIT. [source]

Long,term culture of multibacillary leprosy macrophages isolated from skin lesions: a new model to study Mycobacterium leprae,human cell interaction

BRITISH JOURNAL OF DERMATOLOGY, Issue 2 2007
D.F. Moura
Summary Background, Leprosy is characterized by a disease spectrum having two polar clinical forms dependent on the presence or not of cell-mediated immunity. In the tuberculoid forms, granuloma-activated macrophages kill Mycobacterium leprae in conjunction with a Th1 response while, in multibacillary (MB) lesions, M. leprae nonactivated macrophages infiltrate the nerves and internal organs together with a Th2 response. The functional properties and activation pathways of macrophages isolated from patients with MB leprosy remain only partially understood. Objectives, To establish an ex vivo methodology capable of evaluating the activation pathways, grade and fate of cultured macrophages isolated from MB lesions. Methods, Skin biopsies from patients with borderline tuberculoid, bordeline lepromatous and lepromatous leprosy (LL) were characterized by immunohistochemistry and transcriptional analysis. To isolate inflammatory cells, a portion of the samples was submitted to enzymatic digestion. These same cells, maintained in culture for a minimum 7-day period, were characterized morphologically and via flow cytometry at different culture time points. Cytokine [interferon (IFN)-,, tumour necrosis factor (TNF)-, and interleukin (IL)-10] mRNA levels were quantified by real-time polymerase chain reaction and protein secretion in the culture supernatants was measured by enzyme-linked immunosorbent assay and the nitric oxide levels by Griess reagent. Results, RNA expression in tuberculoid and MB lesions showed the profile expected of characteristic Th1 and Th2 responses, respectively. The inflammatory cells in all biopsies were successfully isolated. Although the number of cells varied between biopsies, it was highest in LL biopsies. The frequency of isolated CD14+ and CD3+ cells measured by flow cytometry correlated with the percentages of macrophages and lymphocytes in the lesions. Throughout the culture period, CD68+ macrophages showed morphological changes. A progressive increase in cell number and reduction of infected cells were perceptible in the cultures. In contrast to the biopsies, TNF-,, IFN-, and IL-10 expression in the tuberculoid and MB leprosy cells in 24-h culture and the cytokine levels in the supernatants did not differ significantly. During the culture period, cytokine expression in the MB cells progressively declined, whereas, from days 1 to 7, nitrite levels progressively increased. After day 40, the remaining macrophages were able to ingest fluorescein isothiocyanate-labelled M. leprae. These data need to be confirmed. Conclusions, This study confirmed the feasibility of obtaining ex vivo macrophages from leprosy lesions and keeping them in long-term culture. This procedure may open new pathways to studying the interaction between M. leprae and human macrophages, which might, in turn, lead to the development of therapeutic tools capable of overcoming the specific anergy found in patients with MB leprosy. [source]

Intranasal exposure to a damp building mould, Stachybotrys chartarum, induces lung inflammation in mice by satratoxin-independent mechanisms

CLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2003
M. Leino
Summary Background Stachybotrys chartarum is a damp building mould and a potent toxin producer that has been related to serious cases of respiratory health problems. However, the direct link between exposure and health symptoms has not been established. Objective To examine the mechanism by which exposure to spores of satratoxin producing and non-producing S. chartarum strains induce inflammatory responses in murine lungs. Methods BALB/c mice were intranasally exposed for 3 weeks to spores of a satratoxin-producing and a non-producing S. chartarum strain. Inflammatory cell infiltration was characterized from bronchoalveolar lavage (BAL) fluid. Cytokine and chemokine mRNA expression in lung tissue was measured with real-time PCR. Bronchial responsiveness to methacholine (MCh) was determined by whole-body plethysmography and serum antibody levels by ELISA. Results A dose-dependent increase in monocytes, neutrophils and lymphocytes was observed in BAL fluid after intranasal (i.n.) instillation of S. chartarum spores. There was no difference in the BAL between exposure to the satratoxin-producing and the non-producing strains. Infiltration of inflammatory cells was associated with an induction of pro-inflammatory cytokine (IL-1,, IL-6 and TNF-,) and chemokine (CCL3/MIP-1,, CCL4/MIP-1, and CCL2/MCP-1) mRNA levels in the lungs. Interestingly, CXCL5/LIX was the only chemokine that showed significantly higher mRNA levels after exposure to the satratoxin-producing strain compared with the non-producing strain. MCh-induced bronchial responsiveness was not altered significantly after mould instillation. Moreover, no significant increase in total or specific IgE, IgG2a and IgG1 antibody levels were found after S. chartarum exposure. Conclusion These results indicate that lung inflammation induced by i.n. instillations of S. chartarum spores is regulated by the induction of pro-inflammatory cytokines and leucocyte-attracting chemokines. The data also imply that S. chartarum -derived components, other than satratoxins, are mediating the development of this inflammatory response. [source]

Subcutaneous administration of collagen-polyvinylpyrrolidone down regulates IL-1,, TNF-,, TGF-,1, ELAM-1 and VCAM-1 expression in scleroderma skin lesions

CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 1 2005
J. Furuzawa-Carballeda
Summary In this study the effect of collagen-polyvinylpyrrolidone (collagen-PVP) vs. triamcinolone acetonide (Triam) in scleroderma (SSc) skin lesions was evaluated. Ten SSc patients were treated weekly with subcutaneous injections of 0.2 mL Triam (8 mg/mL) or 0.2 mL collagen-PVP (1.66 mg collagen). Skin biopsies were obtained from lesions before and after treatment. Tissue sections were evaluated by histology and immunohistochemistry (ELAM-1, VCAM-1, IL-1,, TNF-,, TGF-,1 and PDGF). The corticoid-treated group showed abnormal tissue architecture while the biodrug-treatment restored cutaneous appendages and type I/III collagen proportion. Cytokine and adhesion molecule expression was almost inhibited with Triam, while collagen-PVP down-regulated it. Collagen-PVP improved the tissue architecture of SSc lesions and down-regulated some proinflammatory parameters, without the side effects induced by corticoids. [source]

Cytokine and anti-cytokine therapy in asthma: ready for the clinic?

CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 1 2009
D. Desai
Summary Asthma is a common disease with an increasing prevalence worldwide. Up to 10% of these patients have asthma that is refractory to current therapy. This group have a disproportionate use of health care resources attributed to asthma, have significant morbidity and mortality and therefore represent an unmet clinical need. Asthma is a complex heterogeneous condition that is characterized by typical symptoms and disordered airway physiology set against a background of airway inflammation and remodelling. The inflammatory process underlying asthma is co-ordinated by a cytokine network. Modulating this network with biological therapy presents a new paradigm for asthma treatment. Clinical trials undertaken to date have underscored the complexity of the inflammatory profile and its relationship to the clinical features of the disease and have raised the importance of safety considerations related to these novel therapies. T helper type 2 cytokine blockade remains the most promising strategy, with anti-interleukin-5 reducing asthma exacerbations. Although anti-cytokine therapy is not yet ready for the clinic, the long-awaited possibility of new treatments for severe asthma is moving ever closer. [source]

P73 The magnitude of contact allergy responses can be quantified with imaged perfusion

CONTACT DERMATITIS, Issue 3 2004
Bolli Bjarnason
Objective:, The objective of this study was to determine whether the magnitude of the perfusion of the contact hypersensitivity response as measured by the laser Doppler perfusion imaging (LDPI) technique was associated with immunological parameters implicated in the pathogenesis of the disease. Methods:, Urushiol was applied on one of the forearms of volunteers for 48 hours while the other forearm served as a control. Twenty-four hours later, measurements of perfusion of the patch test sites were performed with the LDPI technique. To determine whether there was a correlation with immunological parameters associated with human contact hypersensitivity, suction blisters were produced at the test sites. Blister fluid was removed and examined for the cytokine interleukin-8 (IL-8). Results:, There was an extremely close correlation between the magnitude of the contact hypersensitivity response as measured by the imaged perfusion and the level of IL-8 in the blister fluid (r = 1.00). Compared to subjects with visually positive urushiol reactions, patients who failed to develop urushiol contact hypersensitivity despite repeated exposures to that substance had both greatly diminished perfusion and blister fluid IL-8 levels. Conclusion:, The results indicate that LDPI is a sensitive method of quantifying contact hypersensitivity reactions in humans and that the magnitude of the measurements with this technique correlates extremely well with cutaneous cytokine levels that have been implicated in the immunopathogenesis of contact hypersensitivity. [source]

Overload-induced skeletal muscle extracellular matrix remodelling and myofibre growth in mice lacking IL-6

ACTA PHYSIOLOGICA, Issue 4 2009
J. P. White
Abstract Aim:, Overloading healthy skeletal muscle produces myofibre hypertrophy and extracellular matrix remodelling, and these processes are thought to be interdependent for producing muscle growth. Inflammatory cytokine interleukin-6 (IL-6) gene expression is induced in overloaded skeletal muscle, and the loss of this IL-6 induction can attenuate the hypertrophic response to overload (OV). Although the OV induction of IL-6 in skeletal muscle may be an important regulator of inflammatory processes and satellite cell proliferation, less is known about its role in the regulation of extracellular matrix remodelling. The purpose of the current study was to examine if OV-induced extracellular matrix remodelling, muscle growth, and associated gene expression were altered in mice that lack IL-6, when compared with wild-type mice. Methods:, Male C57/BL6 (WT) and C57/BL6 × IL-6,/, (IL-6,/,) mice (10 weeks of age) were assigned to either a sham control or synergist ablation OV treatments for 3, 21 or 56 days. Result:, Plantaris muscle mass increased 59% in WT and 116% in IL-6,/, mice after 21 day OV. Myofibre CSA was also increased by 21 day OV in both WT and IL-6,/, mice. OV induced a twofold greater increase in the volume of non-contractile tissue in IL-6,/, muscle compared to WT. OV also induced a significantly greater accumulation of hydroxyproline and procollagen-1 mRNA in IL-6,/, muscle, when compared with WT muscle after 21 day OV. Transforming growth factor-, and insulin-like growth factor-1 mRNA expression were also induced to a greater extent in IL-6,/, muscle when compared with WT muscle after 21 day OV. There was no effect of IL-6 loss on the induction of myogenin, and cyclin D1 mRNA expression after 3 day OV. However, MyoD mRNA expression in 3 day OV IL-6,/, muscle was attenuated when compared with WT OV mice. Conclusion:, IL-6 appears to be necessary for the normal regulation of extracellular matrix remodelling during OV-induced growth. [source]

Inflammatory cytokines augments TGF-,1-induced epithelial-mesenchymal transition in A549 cells by up-regulating T,R-I

CYTOSKELETON, Issue 12 2008
Xiangde Liu
Abstract Epithelial-mesenchymal transition (EMT) is believed to play an important role in fibrosis and tumor invasion. EMT can be induced in vitro cell culture by various stimuli including growth factors and matrix metalloproteinases. In this study, we report that cytomix (a mixture of IL-1,, TNF-, and IFN-,) significantly enhances TGF-,1-induced EMT in A549 cells as evidenced by acquisition of fibroblast-like cell shape, loss of E-cadherin, and reorganization of F-actin. IL-1, or TNF-, alone can also augment TGF-,1-induced EMT. However, a combination of IL-1, and TNF-, or the cytomix is more potent to induce EMT. Cytomix, but not individual cytokine of IL-1,, TNF-, or IFN-,, significantly up-regulates expression of TGF-, receptor type I (T,R-I). Suppression of T,R-I, Smad2 or Smad3 by siRNA partially blocks EMT induction by cytomix plus TGF-,1, indicating cytomix augments TGF-,1-induced EMT through enhancing T,R-I and Smad signaling. These results indicate that inflammatory cytokines together with TGF-,1 may play an important role in the development of fibrosis and tumor progress via the mechanism of epithelial-mesenchymal transition. Cell Motil. Cytoskeleton 2008. © 2008 Wiley-Liss, Inc. [source]

Increased Glycosaminoglycans Production in Sclerosing Basal Cell Carcinoma-Derived Fibroblasts and Stimulation of Normal Skin Fibroblast Glycosaminoglycans Production by a Cytokine-Derived from Sclerosing Basal Cell Carcinoma

DERMATOLOGIC SURGERY, Issue 11 2000
Ronald L. Moy MD
Sclerosing basal cell carcinoma (S-BCC) is characterized by an abundant stroma. There is evidence that some tumor cells secrete cytokines that are mitogenic for stromal fibroblasts (FBs). From this study we report increased glycosaminoglycan (GAG) production by cultures of S-BCC FBs in comparison to cultures of nodular BCC (N-BCC) FBs and normal skin FBs. GAG production was measured by cetylpyridinium chloride precipitation of incorporated [3H]-glucosamine. The sclerosing BCC FBs demonstrated a significant increase in production of GAG over control FBs (P < .001) and over N-BCC FBs (P < .001). Values reported as a mean percentage ± SEM for GAG production by S-BCC over control normal skin FBs are 359 ± 28 and over N-BCC FBs are 266 ± 27. In additional experiments, cell extract dilutions from S-BCC tumor, normal dermis, and normal epidermis were incubated with cultures of normal skin FBs. S-BCC-conditioned media was also incubated with normal FBs and GAG production was measured. For both S-BCC extracts and conditioned media, a dose response curve was established showing increased GAG production by normal FBs in relation to increasing the concentration of S-BCC extract or conditioned media. When S-BCC extract was added to normal FBs there was increased GAG production in comparison to normal FBs incubated with dermal or epidermal extracts (P < .001) for both. Two growth factors, transforming growth factor-, (TGF-,) and platelet-derived growth factor (PDGF), already known to be mitogenic for FBs, were incubated with N-BCC and normal FBs in an effort to elucidate the potential cytokine(s) released by S-BCC, causing increased GAG production by surrounding FBs. Neither of these cytokines proved to be effective in promoting a significant increase in GAG production. Our findings support the hypothesis that BCCs release factors that alter stromal FB production of GAG. [source]

Effect of Perilesional Injections of PEG-Interleukin-2 on Basal Cell Carcinoma

DERMATOLOGIC SURGERY, Issue 11 2000
Baruch Kaplan MD
Background: Multiple modalities are available for the treatment of basal cell carcinoma (BCC). The most commonly used modalities include simple excision, Mohs micrographic surgery, curettage and electrodessication, cryosurgery, and irradiation therapy. Interleukin-2 (IL-2) is a cytokine produced chiefly by activated T lymphocytes and has effects on various components of the immune system. Until now the primary clinical use of IL-2 has been in advanced stages of metastatic melanoma and renal cell carcinoma. Systemic administration of IL-2 is known to cause significant toxicity. Objective: The objective of this study was to evaluate the therapeutic efficacy and safety of perilesional PEG-IL-2 injections in patients with BCC in an open label, uncontrolled pilot study. Methods: Patients with histologically confirmed primary BCC over 18 years of age were included in the study. Lesions were treated by injecting a total volume of 0.5 cc of IL-2 in a radial fashion in the subcutaneous tissue. Injection dosages ranged from 3000 to 1,200,000 IU in one to four weekly dosages. A total of 12 tumors were treated in eight patients. Results: Overall response rates were as follows: complete response in 8 of 12 treated tumors (66.6% cure rate), partial response in 3 of 12 injected tumors (25% partial response rate), stable disease with no improvement in 1 treatment site (8.4%). Side effects included local pain, swelling, and erythema, and in one patient flulike symptoms. There were no significant changes of blood tests as compared to baseline levels. Conclusions: The therapeutic response induced by perilesional PEG-IL-2 injections was found to be an encouraging, safe, and well-tolerated treatment of BCC. Further studies including a larger patient population and long-term follow-up are necessary in order to substantiate these findings. [source]

Genetic variations associated with psoriasis and psoriatic arthritis found by genome-wide association

DERMATOLOGIC THERAPY, Issue 2 2010
Kristina Callis Duffin
ABSTRACT Psoriasis and psoriatic arthritis are immune disorders with a complex polygenic basis. HLA-Cw6, which lies in the major histocompatibility region on chromosome 6, is considered the major genetic determinant of psoriasis. Recent genome-wide association studies have identified new variants outside of the MHC with relevance to the immunology of psoriasis. Variants in or near genes that encode subunits of cytokines (IL12B, IL23A) or cytokine receptors (IL23R) are interesting given that the gene product of IL12B, p40, is the target of a recently approved monoclonal antibody therapy for psoriasis (ustekinumab). Association with psoriasis and psoriatic arthritis has been found in TNFAIP3 and TNFIP1, ubiquitin ligases in the NF-,B pathway, and IL13, a Th2 cytokine. Copy number variation of human beta-defensin and late cornified envelope genes also associate with psoriasis. Many of these genetic variations also associate with immune disorders considered psoriatic co-morbidities, including Crohn's disease and diabetes. [source]

Cardiac expression patterns of endothelin-converting enzyme (ECE): Implications for conduction system development

DEVELOPMENTAL DYNAMICS, Issue 6 2008
David Sedmera
Abstract The spatiotemporal distribution of the endothelin-converting enzyme (ECE) protein in the embryonic chick heart and the association of this polypeptide with the developing cardiac conduction system is described here for the first time. Further, we show how cardiac hemodynamic load directly affects ECE level and distribution. Endothelin (ET) is a cytokine involved in the inductive recruitment of Purkinje fibers. ET is produced by proteolytic cleavage of Big-ET by ECE. We generated an antibody against chick ECE recognizing a single band at ,70 kD to correlate the cardiac expression of this protein with that reported previously for its mRNA. ECE protein expression was more widespread compared to its mRNA, being present in endothelial cells, mesenchymal cells, and myocytes, and particularly enriched in the trabeculae and nascent ventricular conduction system. The myocardial expression was significantly modified under experimentally altered hemodynamic loading. In vivo, ET receptor blockade with bosentan delayed activation sequence maturation. These data support a role for ECE in avian cardiac conduction system differentiation and maturation. Developmental Dynamics 237:1746,1753, 2008. © 2008 Wiley-Liss, Inc. [source]

Stress experienced in utero reduces sexual dichotomies in neurogenesis, microenvironment, and cell death in the adult rat hippocampus

DEVELOPMENTAL NEUROBIOLOGY, Issue 5 2008
Chitra D. Mandyam
Abstract Hippocampal function and plasticity differ with gender, but the regulatory mechanisms underlying sex differences remain elusive and may be established early in life. The present study sought to elucidate sex differences in hippocampal plasticity under normal developmental conditions and in response to repetitive, predictable versus varied, unpredictable prenatal stress (PS). Adult male and diestrous female offspring of pregnant rats exposed to no stress (control), repetitive stress (PS-restraint), or a randomized sequence of varied stressors (PS-random) during the last week of pregnancy were examined for hippocampal proliferation, neurogenesis, cell death, and local microenvironment using endogenous markers. Regional volume was also estimated by stereology. Control animals had comparable proliferation and regional volume regardless of sex, but females had lower neurogenesis compared to males. Increased cell death and differential hippocampal precursor kinetics both appear to contribute to reduced neurogenesis in females. Reduced local interleukin-1beta (IL-1,) immunoreactivity (IR) in females argues for a mechanistic role for the anti-apoptotic cytokine in driving sex differences in cell death. Prenatal stress significantly impacted the hippocampus, with both stress paradigms causing robust decreases in actively proliferating cells in males and females. Several other hippocampal measures were feminized in males such as precursor kinetics, IL-1,-IR density, and cell death, reducing or abolishing some sex differences. The findings expand our understanding of the mechanisms underlying sex differences and highlight the critical role early stress can play on the balance between proliferation, neurogenesis, cell death, and hippocampal microenvironment in adulthood. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008. [source]

Adipocyte prolactin: regulation of release and putative functions

DIABETES OBESITY & METABOLISM, Issue 4 2007
T. Brandebourg
Pituitary-derived prolactin (PRL) is a well-known regulator of the lactating mammary gland. However, the recent discovery that human adipose tissue produces PRL as well as expresses the PRL receptor (PRLR) highlights a previously unappreciated action of PRL as a cytokine involved in adipose tissue function. Biologically active PRL is secreted by all adipose tissue depots examined: breast, visceral and subcutaneous. The expression of adipose PRL is regulated by a non-pituitary, alternative superdistal promoter. PRL expression and release increases during early pre-adipocyte differentiation and is stimulated by cyclic AMP activators, including , adrenergic receptor agonists. PRL release from subcutaneous adipose explants is attenuated during obesity, suggesting that adipose PRL production is altered by the metabolic state. Several lines of evidence indicate that PRL suppresses lipid storage as well as the release of adipokines such as adiponectin, interleukin-6 and possibly leptin. PRL has also been implicated in the regulation of adipogenesis. A newly developed PRL-secreting human adipocyte cell line, LS14, should allow comprehensive examination of the regulation and function of adipocyte-derived PRL. Collectively, these studies raise the prospect that PRL affects energy homeostasis through its action as an adipokine and is involved in the manifestation of insulin resistance. [source]

Advanced glycation end products-induced apoptosis attenuated by PPAR, activation and epigallocatechin gallate through NF-,B pathway in human embryonic kidney cells and human mesangial cells

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 5 2010
Yao-Jen Liang
Abstract Background Diabetic nephropathy has attracted many researchers' attention. Because of the emerging evidence about the effects of advanced glycation end products (AGEs) and receptor of AGE (RAGE) on the progression of diabetic nephropathy, a number of different therapies to inhibit AGE or RAGE are under investigation. The purpose of the present study was to examine whether peroxisome proliferator-activated receptor , (PPAR,) agonist (L-165041) or epigallocatechin gallate (EGCG) alters AGE-induced pro-inflammatory gene expression and apoptosis in human embryonic kidney cells (HEK293) and human mesangial cells (HMCs). Methods The HEK cells and HMC were separated into the following groups: 100 µg/mL AGE alone for 18 h; AGE treated with 1 µM L-165041 or 10 µM EGCG, and untreated cells. Inflammatory cytokines, nuclear factor-,B pathway, RAGE expression, superoxide dismutase and cell apoptosis were determined. Results AGE significantly increased tumour necrosis factor-, (TNF-,), a major pro-inflammatory cytokine. The mRNA and protein expression of RAGE were up-regulated. These effects were significantly attenuated by pre-treatment with L-165041 or EGCG. AGE-induced nuclear factor-,B pathway activation and both cells apoptosis were also inhibited by L-165041 or EGCG. Furthermore, both L-165041 and EGCG increased superoxide dismutase levels in AGE-treated HEK cells and HMC. Conclusions This study demonstrated that PPAR, agonist and EGCG decreased the AGE-induced kidney cell inflammation and apoptosis. This study provides important insights into the molecular mechanisms of EGCG and PPAR, agonist in attenuation of kidney cell inflammation and may serve as a therapeutic modality to treat patients with diabetic nephropathy. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Circulating adipocytokines in non-diabetic and Type 1 diabetic children: relationship to insulin therapy, glycaemic control and pubertal development

DIABETIC MEDICINE, Issue 6 2006
F. Celi
Abstract Aim To determine the influence of Type 1 diabetes mellitus on circulating adipocytokines in children. Methods The circulating concentrations of leptin, adiponectin, resistin and tumour necrosis factor (TNF)-, were measured in 91 children, aged 11.1 ± 2.7 years, with Type 1 diabetes mellitus (T1DM). Ninety-one healthy children were selected as control subjects. Results Body mass index-adjusted leptin concentrations were higher in the pubertal diabetic children compared with the control children. There was a significant positive correlation between leptin and daily insulin dose in the diabetic group. Circulating adiponectin concentrations were higher in the prepubertal diabetic children and were positively associated with HbA1c. Resistin concentrations were lower in the prepubertal non-diabetic subjects compared with the pubertal non-diabetic children, whose values were higher than those of the diabetic children. TNF-, concentrations were similar in non-diabetic and diabetic children. Conclusions Circulating concentrations of adipocytokines are abnormal in Type 1 diabetic children, although the direction of change differs by cytokine. Pubertal development, in addition to insulin treatment and glycaemic control, also influences the concentrations. [source]

Construction of an antibody microarray based on agarose-coated slides

ELECTROPHORESIS, Issue 3 2007
Lin-Li Lv
Abstract The antibody microarray, a high-throughput multiplex immunoassay method, has become a significant tool for quantitative proteomics studies. We describe here the strategies for optimizing the condition of antibody microarray building based on agarose-coated slides. In this study, modified glass slides were robotically printed with capture antibodies against monocyte chemoattractant protein 1 (MCP-1), then dilutions of the cytokine were applied to the arrays, and the protein was detected with biotin-labeled antibody coupled with Cy3-conjugated streptavidin. Thus a protein profiling microarray based on sandwich immunoassay has been established. Various factors in the production of antibody microarrays were analyzed: the capture antibody concentrations, shelf life of the postprinting slides, blocking buffers, and reproducibility of the system. A calibration curve with a correlation coefficient of 0.9995 was established which suggested that the matrix can retain arrayed proteins in near-quantitative fashion. The results revealed high signal uniformity and reproducibility with regard to intra-array (1.3%) and the interarray (8.7%) variation at the capture antibody concentration of 125,µg/mL. Besides, the printed arrays could be stored for at least two months without any apparent change of the performance parameters. [source]

Interleukin-10 is associated with resistance to febrile seizures: Genetic association and experimental animal studies

EPILEPSIA, Issue 4 2009
Yoshito Ishizaki
Summary Purpose:, Febrile seizures (FS) are the most common form of childhood convulsions. Many reports have shown that a proinflammatory cytokine, interleukin-1 (IL-1) ,, may have a facilitatory effect on the development of FS. We have previously shown that the IL1B -511C/T single nucleotide polymorphism (SNP) is associated with simple FS of sporadic occurrence. The balance between pro- and antiinflammatory cytokines influences the regulation of infections and could, therefore, play a role in the pathogenesis of FS. Here, to determine whether pro- and antiinflammatory cytokine genes are responsible for the susceptibility to FS, we have performed an association study on functional SNPs of cytokine genes in FS patients and controls. Methods:, The promoter SNPs of four inflammatory cytokine genes (IL6 -572C/G, IL8 -251A/T, IL10 -592A/C and TNFA -1037C/T) were examined in 249 patients with FS (186 simple and 63 complex FS) and 225 controls. Because the IL10 -592 SNP showed a positive association with FS, two additional SNPs (IL10 -1082A/G and -819T/C) were subjected to haplotype analysis. Furthermore, we examined the in vivo role of IL-10 in hyperthermia-induced seizures using immature animal models. Results:, The frequencies of the IL10 -592C allele and -1082A/-819C/-592C haplotype were significantly decreased in FS as compared with in controls (p = 0.014 and 0.013, respectively). The seizure threshold temperature in the IL-10,administered rats was significantly higher than that in the saline-treated control ones (p = 0.027). Conclusions:, The present study suggests that IL-10 is genetically associated with FS and, contrary to IL-1,, confers resistance to FS. [source]

Causal Links between Brain Cytokines and Experimental Febrile Convulsions in the Rat

EPILEPSIA, Issue 12 2005
James G. Heida
Summary:,Purpose: Despite the prevalence of febrile convulsions (FCs), their pathophysiology has remained elusive. We tested the hypothesis that components of the immune response, particularly the proinflammatory cytokine interleukin-1, (IL-1,) and its naturally occurring antagonist interleukin-1 receptor antagonist (IL-1ra) may play a role in the genesis of FC. Methods: Postnatal day 14 rats were treated with lipopolysaccharide (LPS; 200 ,g/kg, i.p.) followed by a subconvulsant dose of kainic acid (1.75 mg/kg, i.p.). Brains were harvested at and 2 h after onset of FCs to measure brain levels of IL-1, and IL-1ra. Separate groups of animals were given intracerebroventricular (ICV) injections of IL-1,, or IL-1ra in an attempt to establish a causal relation between the IL-1,/IL-1ra system and FCs. Results: Animals with FCs showed increased IL-1, in the hypothalamus and hippocampus but not in the cortex compared with noFC animals that also received LPS and kainic acid. This increase was first detected in the hippocampus at onset of FCs. No detectable difference in IL-1ra was found in brain regions examined in either group. When animals were treated with IL-1, ICV, a dose-dependant increase was noted in the proportion of animals that experienced FCs, whereas increasing doses of IL-1ra, given to separate groups of animals, were anticonvulsant. Conclusions: Our results suggest that excessive amounts of IL-1, may influence the genesis of FCs. This may occur by overproduction of IL-1,, or by alteration in the IL-1,/IL-1ra ratio in the brain after an immune challenge. [source]

Increased Plasma Levels of Pro- and Anti-inflammatory Cytokines in Patients with Febrile Seizures

EPILEPSIA, Issue 8 2002
Miia Virta
Summary: ,Purpose: Pro- and antiinflammatory cytokines regulate the febrile response during infection. Febrile seizures (FSs) conversely are associated with rapid onset of high fever. Activation of the cytokine network has been shown in previous studies of FSs and cytokines. In this study, the association between cytokines and FSs was further investigated. Methods: Interleukin-1, (IL-1,), interleukin-1 receptor antagonist (IL-1RA), interleukin-6 (IL-6), interleukin-10, and tumor necrosis factor-, plasma levels were measured with enzyme-linked immunosorbent assay in 55 children with FSs and in 20 age-matched febrile controls immediately on arrival at the hospital. Cerebrospinal fluid cytokine levels also were measured in 16 FS children. Results: The plasma IL-1RA/IL-1, ratio (mean, 2,133 vs. 119; median, 790 vs. 105; p < 0.0001) and plasma IL-6 (mean, 41.7 pg/ml vs. 16.1 pg/ml; median, 19.6 pg/ml vs. 10.5 pg/ml; p = 0.005) were significantly higher in FS patients compared with control children. Logistic regression analysis was used to find the most significant predisposing factors for FSs. In this analysis, the high plasma IL-1RA/IL-1, ratio was the most significant factor connected to FSs (OR, 41.5; 95% CI, 4.9,352.8), but high plasma IL-6 also was significantly associated with FSs (OR, 5.3; 95% CI, 1.4,20.3). Conclusions: Present results support the hypothesis that the cytokine network is activated and could have a role in the pathogenesis of FS. [source]

Production of biologically active equine interleukin 12 through expression of p35, p40 and single chain IL-12 in mammalian and baculovirus expression systems

EQUINE VETERINARY JOURNAL, Issue 7 2001
E. L. J. McMONAGLE
Summary Interleukin-12 (IL-12) is a key cytokine in the development of cell-mediated immune responses. Bioactive IL-12 is a heterodimeric cytokine composed of disulphide linked p35 and p40 subunits. The aim of this study was to verify biologically activity of the products expressed from equine interleukin-12 (IL-12) p35 and p40 cDNAs and to establish whether equine IL-12 could be expressed as a p35/p40 fusion polypeptide, as has been reported for IL-12a of several mammalian species. We report production of equine IL-12 through expression of p35 and p40 subunits in mammalian and insect cells and of a p35:p40 fusion polypeptide in mammalian cells. Conditioned medium recovered from cultures transiently transfected with constructs encoding equine p35 and p40 subunits or single chain IL-12 enhanced IFN-, production in cells derived from equine lymph nodes. Preincubation of IFN-, inducing preparations with anti-p40 monoclonal antibody resulted in a significant decrease in IFN-, induction capacity. Medium recovered from p35 and p40-expressing baculovirus infected cultures enhanced target cell IFN-, production and proliferation. Experimental studies in mice and other animals have revealed a therapeutic benefit of IL-12 in cancer, inflammatory and infectious disease and an adjuvant effect in prophylactic regimes. Production of a bioactive species-specific IL-12 is a first step towards an investigation of its potential application in equine species. [source]

Interleukin-10: an anti-atherogenic cytokine?

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 1 2001
A. Tedgui
No abstract is available for this article. [source]

Effective ex vivo expansion of hematopoietic stem cells using osteoblast-differentiated mesenchymal stem cells is CXCL12 dependent

EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 6 2010
Seiji Mishima
Abstract Effective ex vivo expansion of hematopoietic stem cells (HSCs) is a prerequisite for HSC transplantation. Growth and maintenance of HSC is dependent on cytokine and niche factors. We investigated whether mesenchymal stem cells (MSCs) or osteogenic cytokine-differentiated MSCs play a role in HSC expansion. We used the human HM3.B10 (B10) MSC cell line and the osteoblast-differentiated B10 (Ost-B10) as a feeder layer and examined ex vivo expansion of CD34+CD38, HSCs obtained from peripheral blood (PB) and cord blood (CB) with or without several growth cytokines. Both undifferentiated B10 and Ost-B10 cells exhibited similar effects on total HSC expansion; however, Ost-B10 demonstrated a higher potency in CD34+CD38, cell-specific proliferation in the presence of cytokines compared to undifferentiated B10 HSCs. Colony-forming cell assay and long-term culture initiating cell assay revealed that Ost-B10 displayed multipotent differentiation and enabled long-term ex vivo culture of HSCs. We next examined the relationship between HSC expansion and the presence of various chemokines. CXCL4 and CXCL12 expression were increased in Ost-B10 cells compared with the B10 cells. CD34+CD38, cells were significantly increased with CXCL12, but not CXCL4 treatment. siRNA inhibition of CXCL12 decreased CXCL12 secretion in both B10 and Ost-B10, whereas expansion of CD34+CD38, cells was decreased in Ost-B10 alone. These results demonstrated that ex vivo expansion of HSCs may be highly effective through osteoblast-differentiated MSCs acting as a feeder layer, and likely operates through the CXCL12 chemokines signaling pathway. [source]

Transcription factor Fli-1 expression by bone marrow cells in chronic myeloproliferative disorders is independent of an underlying JAK2 (V617F) mutation

EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 6 2006
Oliver Bock
Abstract:,Objectives:,Friend leukemia integration-1 (Fli-1), a member of the Ets gene family of transcription factors, has been demonstrated to be a target of a leukaemia inducing virus in mice, and is known to be part of a fusion gene in Ewings' sarcoma in humans. Wild-type Fli-1 is involved in lineage commitment of megakaryocytes and myeloid progenitors through induction of Janus kinases (JAKs) following ligand binding to cytokine and growth factor receptors. Proliferation of atypical megakaryocytes is a predominant histopathological feature in Philadelphia chromosome negative chronic myeloproliferative disorders (Ph, CMPD) and a potential aberrant expression of Fli-1 has not been investigated so far. Methods:,Fli-1 expression was investigated by real-time RT-PCR and immunohistochemistry in bone marrow cells derived from Ph, CMPD (n = 80) and non-neoplastic haematopoiesis (n = 21) following determination of the JAK2 status. Results:,Fli-1 mRNA expression was significantly higher in Essential thrombocythaemia (ET) with JAK2 (V617F) compared with other Ph, CMPD and control (P < 0.001). By immunohistochemistry, Fli-1 protein could be detected in nuclei of atypical megakaryocytes in Ph, CMPD and, less accentuated, in non-neoplastic megakaryocytes. Fli-1 protein expression by myeloid progenitors was considerably heterogenous in Ph, CMPD independent of an underlying JAK2 (V617F) mutation and without notable differences to non-neoplastic haematopoiesis. Conclusion:,Fli-1 is rather constitutively expressed by bone marrow cells in Ph, CMPD independent of the underlying JAK2 status. The overall stronger labelling for Fli-1 in megakaryocytes in Ph, CMPD most likely reflects the degree of polyploidisation but aberrant activation of nuclear target genes can not be excluded. [source]

Effects of angiogenic regulators on in vitro proliferation and cytokine secretion by native human acute myelogenous leukemia blasts

EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 1 2003
Øystein Bruserud
Abstract: Angiogenesis seems to be important in the pathogenesis of acute myelogenous leukemia (AML). The endothelial cell proliferation and microvessel formation are regulated by a wide range of soluble mediators, including angiogenin, angiopoietin-2, basic fibroblast growth factors, vascular endothelial growth factor (VEGF), VEGF-D, angiostatin and endostatin. In the present study, it has been investigated whether these mediators have an additional direct effect on the proliferation and cytokine release by native human AML blasts. AML cells derived from a large group of consecutive patients were investigated. All these mediators could alter the proliferation and cytokine release [interleukin (IL) 1,, IL6, IL8, tumor necrosis factor ,] for a minority of patients. Alteration of spontaneous proliferation by at least one mediator was detected in five of 38 patients; whereas, altered cytokine (Flt3-ligand, granulocyte-macrophage colony-stimulating factor, stem cell factor)-dependant proliferation was observed for 10 patients. Growth enhancement was most frequently observed, whereas growth inhibition was uncommon. The effects on AML blast proliferation were often dependant on or were modulated by the presence of the three hematopoietic growth factors. Based on the present results, it is concluded that angioregulatory mediators have additional growth-enhancing effects directly on the AML blasts for certain patients. However, based on the results from this investigation and previous studies it is suggested that their major contribution to the pathogenesis of AML is through their effects on regulation of bone marrow angiogenesis, and future studies of these mediators in AML should probably focus on these effects. [source]

Haematopoietic progenitor cells from the common marmoset as targets of gene transduction by retroviral and adenoviral vectors

EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 4 2001
Hitoshi Hibino
Abstract: To establish a new non-human primate model for human cytokine and gene therapy, we characterized lymphocytes and haematopoietic progenitor cells of the small New World monkey, the common marmoset. We first assessed the reactions of marmoset bone marrow (BM) and peripheral blood (PB) cells to mouse anti-human monoclonal antibodies (mAbs) for the purpose of isolating marmoset lymphocytes and haematopoietic progenitor cells. Both cell fractions stained with CD4 and CD8 mAbs were identified as lymphocytes by cell proliferation assay and morphological examination. Myeloid-specific mAbs such as CD14 and CD33 did not react with marmoset BM and PB cells. No available CD34 and c-kit mAbs could be used to purify the marmoset haematopoietic progenitor cells. Furthermore, we studied the in vitro transduction of the bacterial ,-galactosidase (LacZ) gene into CFU-GM derived from marmoset BM using retroviral and adenoviral vectors. The transduction efficiency was increased by using a mixed culture system consisting of marmoset BM stromal cells and retroviral producer cells. It was also possible to transduce LacZ gene into marmoset haematopoietic progenitor cells with adenoviral vectors as well as retroviral vectors. The percentage of adenovirally transduced LacZ-positive clusters was 15% at day 4 (multiplicity of infection=200), but only 1,2% at day 14. The differential use of viral vector systems is to be recommended in targeting different diseases. Our results suggested that marmoset BM progenitor cells were available to examine the transduction efficiency of various viral vectors in vitro. [source]

IL-6: Regulator of Treg/Th17 balance

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 7 2010
Akihiro Kimura
Abstract IL-6 is a pleiotropic cytokine involved in the physiology of virtually every organ system. Recent studies have demonstrated that IL-6 has a very important role in regulating the balance between IL-17-producing Th17 cells and regulatory T cells (Treg). The two T-cell subsets play prominent roles in immune functions: Th17 cell is a key player in the pathogenesis of autoimmune diseases and protection against bacterial infections, while Treg functions to restrain excessive effector T-cell responses. IL-6 induces the development of Th17 cells from naïve T cells together with TGF-,; in contrast, IL-6 inhibits TGF-,-induced Treg differentiation. Dysregulation or overproduction of IL-6 leads to autoimmune diseases such as multiple sclerosis (MS) and rheumatoid arthritis (RA), in which Th17 cells are considered to be the primary cause of pathology. Given the critical role of IL-6 in altering the balance between Treg and Th17 cells, controlling IL-6 activities is potentially an effective approach in the treatment of various autoimmune and inflammatory diseases. Here, we review the role of IL-6 in regulating Th17/Treg balance and describe the critical functions of IL-6 and Th17 in immunity and immune-pathology. [source]

In vitro -induced Th17 cells fail to induce inflammation in vivo and show an impaired migration into inflamed sites

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 4 2010
Marko Janke
Abstract Recently, IL-17 produced by Th17 cells was described as pro-inflammatory cytokine with an eminent role in autoimmune diseases, e.g. rheumatoid arthritis. A lack of IL-17 leads to amelioration of collagen-induced arthritis. IL-17 induction in naïve CD4+ T cells depends on IL-6 and TGF-, and is enhanced by IL-23. The in vivo inflammatory potential of in vitro -primed Th17 cells however, remains unclear. Here, we show that, although IL-17 neutralisation results in amelioration of murine OVA-induced arthritis, in vitro -primed Th17 cells cannot exacerbate arthritic symptoms after adoptive transfer. Furthermore, Th17 cells cannot induce an inflammatory delayed type hypersensitivity reaction because they fail to migrate into inflamed sites, possibly due to the lack of CXCR3 expression. Also, re-isolated Th17 cells acquired IFN-, expression, indicating instability of the Th17 phenotype. Taken together, the data show that IL-6, TGF-, and IL-23 might not provide sufficient signals to induce "fully qualified" Th17 cells. [source]

A bone-protective role for IL-17 receptor signaling in ovariectomy-induced bone loss

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 10 2009
Jaya Goswami
Abstract Post-menopausal osteoporosis is considered to be an inflammatory process, in which numerous pro-inflammatory and T-cell-derived cytokines play a bone-destructive role. IL-17A is the signature cytokine of the pro-inflammatory Th17 population and plays dichotomous roles in diseases that affect bone turnover. Although IL-17A promotes bone loss in rheumatoid arthritis, it is protective against pathogen-induced bone destruction in a periodontal disease model. We used a model of ovariectomy-induced osteoporosis (OVX) in IL-17 receptor (IL-17RA),/, mice to evaluate the role of the IL-17A in bone loss caused by estrogen deficiency. Unexpectedly, IL-17RA,/, mice were consistently and markedly more susceptible to OVX-induced bone loss than controls. There were no changes in prototypical Th1, Th2 or Th17 cytokines in serum that could account for increased bone loss. However, IL-17RA,/, mice exhibited constitutively elevated leptin, which further increased following OVX. Consistently, IL-17A and IL-17F treatment of 3T3-L1 pre-adipocytes inhibited adipogenesis, leading to reduced production of leptin. In addition to its role in regulating metabolism and satiety, leptin can regulate bone turnover. Accordingly, these data show that IL-17A negatively regulates adipogenesis and subsequent leptin expression, which correlates with increased bone destruction during OVX. [source]