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Martín-González J, Sánchez-Jiménez F, Pérez-Pérez A, Carmona-Fernández A, Sánchez-Margalet V, Segura-Egea JJ. Leptin expression in healthy and inflamed human dental pulp. Int Endod J 2012; 46:442-8. [DOI: 10.1111/iej.12009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 09/04/2012] [Indexed: 01/03/2023]
Affiliation(s)
- J. Martín-González
- Department of Stomatology (Endodontics section); School of Dentistry,; University of Sevilla,; Sevilla; Spain
| | - F. Sánchez-Jiménez
- Department of Medical Biochemistry and Molecular Biology; Virgen Macarena Hospital,; University of Sevilla,; Sevilla; Spain
| | - A. Pérez-Pérez
- Department of Medical Biochemistry and Molecular Biology; Virgen Macarena Hospital,; University of Sevilla,; Sevilla; Spain
| | - A. Carmona-Fernández
- Department of Medical Biochemistry and Molecular Biology; Virgen Macarena Hospital,; University of Sevilla,; Sevilla; Spain
| | - V. Sánchez-Margalet
- Department of Medical Biochemistry and Molecular Biology; Virgen Macarena Hospital,; University of Sevilla,; Sevilla; Spain
| | - J. J. Segura-Egea
- Department of Stomatology (Endodontics section); School of Dentistry,; University of Sevilla,; Sevilla; Spain
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202
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Schneiderman J, Schaefer K, Kolodgie FD, Savion N, Kotev-Emeth S, Dardik R, Simon AJ, Halak M, Pariente C, Engelberg I, Konstantinides S, Virmani R. Leptin locally synthesized in carotid atherosclerotic plaques could be associated with lesion instability and cerebral emboli. J Am Heart Assoc 2012; 1:e001727. [PMID: 23316287 PMCID: PMC3541612 DOI: 10.1161/jaha.112.001727] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Accepted: 08/02/2012] [Indexed: 12/11/2022]
Abstract
BACKGROUND Unstable carotid plaques cause cerebral emboli. Leptin promotes atherosclerosis and vessel wall remodeling. We hypothesized that carotid atherosclerotic lesion instability is associated with local leptin synthesis. METHODS AND RESULTS Carotid endarterectomy plaques from symptomatic (n=40) and asymptomatic patients with progressive stenosis (n=38) were analyzed for local expression of leptin, tumor necrosis factor (TNF)-α, and plasminogen activator inhibitor type 1. All lesions exhibited advanced atherosclerosis inclusive of thick- and thin-cap fibroatheromas or lesion rupture. Symptomatic lesions exhibited more plaque ruptures and macrophage infiltration (P=0.001 and P=0.05, respectively). Symptomatic plaques showed preferential leptin, TNF-α, and plasminogen activator inhibitor type 1 transcript (P=0.03, P=0.04, and P=0.05, respectively). Leptin mRNA and antigen in macrophages and smooth muscle cells were confirmed by in situ hybridization and immunohistochemistry. Plasma leptin levels were not significantly different between groups (P=1.0), whereas TNF-α was significantly increased in symptomatic patients (P=0.006). Human aortic smooth muscle cell culture stimulated by TNF-α, lipopolysaccharide, or lipoteichoic acid revealed 6-, 6.7-, and 6-fold increased secreted leptin antigen, respectively, at 72 hours (P<0.05). CONCLUSIONS Neurologically symptomatic patients overexpress leptin mRNA and synthesize leptin protein in carotid plaque macrophages and smooth muscle cells. Local leptin induction, presumably by TNF-α, could exert paracrine or autocrine effects, thereby contributing to the pathogenesis of lesion instability. CLINICAL TRIAL REGISTRATION URL: www.Clinicaltrials.gov. Unique identifier: NCT00449306.
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Affiliation(s)
- Jacob Schneiderman
- Department of Vascular Surgery and the Gottesdiener Vascular Biology Laboratory, Sheba Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Israel.
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203
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Obesity, Inflammation and Acute Myocardial Infarction - Expression of leptin, IL-6 and high sensitivity-CRP in Chennai based population. Thromb J 2012; 10:13. [PMID: 22891684 PMCID: PMC3444897 DOI: 10.1186/1477-9560-10-13] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 08/02/2012] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Obesity, characterised by increased fat mass and is currently regarded as a pro-inflammatory state and often associated with increased risk of cardiovascular diseases (CVD) including Myocardial infarction. There is an upregulation of inflammatory markers such as interleukin-6, interleukin-6 receptor and acute phase protein CRP in Acute Myocardial Infarction (AMI) patients but the exact mechanism linking obesity and inflammation is not known. It is of our interest to investigate if serum leptin (ob gene product) is associated with AMI and correlated with inflammatory proteins namely Interleukin-6 (IL-6) and high sensitivity - C reactive protein (hs-CRP). RESULTS Serum leptin levels were significantly higher in AMI patients when compared to Non-CVD controls. IL-6 and hs-CRP were also elevated in the AMI group and leptin correlated positively with IL-6 and hs-CRP. Incidentally this is the first report from Chennai based population, India. CONCLUSIONS The strong correlation between serum levels of leptin and IL-6 implicates an involvement of leptin in the upregulation of inflammatory cytokines during AMI. We hypothesise that the increase in values of IL-6, hs-CRP and their correlation to leptin in AMI patients could be due to participation of leptin in the signaling cascade after myocardial ischemia.
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204
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Carlton ED, Demas GE, French SS. Leptin, a neuroendocrine mediator of immune responses, inflammation, and sickness behaviors. Horm Behav 2012; 62:272-9. [PMID: 22561456 DOI: 10.1016/j.yhbeh.2012.04.010] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Revised: 04/05/2012] [Accepted: 04/18/2012] [Indexed: 01/27/2023]
Abstract
Effective immune responses are coordinated by interactions among the nervous, endocrine, and immune systems. Mounting immune, inflammatory, and sickness responses requires substantial energetic investments, and as such, an organism may need to balance energy allocation to these processes with the energetic demands of other competing physiological systems. The metabolic hormone leptin appears to be mediating trade-offs between the immune system and other physiological systems through its actions on immune cells and the brain. Here we review the evidence in both mammalian and non-mammalian vertebrates that suggests leptin is involved in regulating immune responses, inflammation, and sickness behaviors. Leptin has also been implicated in the regulation of seasonal immune responses, including sickness; however, the precise physiological mechanisms remain unclear. Thus, we discuss recent data in support of leptin as a mediator of seasonal sickness responses and provide a theoretical model that outlines how seasonal cues, leptin, and proinflammatory cytokines may interact to coordinate seasonal immune and sickness responses.
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Affiliation(s)
- Elizabeth D Carlton
- Department of Biology, Program in Neuroscience and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA.
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205
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Abstract
There is strong evidence indicating that excess adiposity negatively impacts immune function and host defence in obese individuals. This is a review of research findings concerning the impact of obesity on the immune response to infection, including a discussion of possible mechanisms. Obesity is characterised by a state of low-grade, chronic inflammation in addition to disturbed levels of circulating nutrients and metabolic hormones. The impact of these metabolic abnormalities on obesity-related comorbidities has undergone intense scrutiny over the past decade. However, relatively little is known of how the immune system and host defence are influenced by the pro-inflammatory and excess energy milieu of the obese. Epidemiological data suggest obese human subjects are at greater risk for nosocomial infections, especially following surgery. Additionally, the significance of altered immunity in obese human subjects is emphasised by recent studies reporting obesity to be an independent risk factor for increased morbidity and mortality following infection with the 2009 pandemic influenza A (H1N1) virus. Rodent models offer important insight into how metabolic abnormalities associated with excess body weight can impair immunity. However, more research is necessary to understand the specific aspects of immunity that are impaired and what factors are contributing to reduced immunocompetence in the obese. Additionally, special consideration of how infection in this at-risk population is managed is required, given that this population may not respond optimally to antimicrobial drugs and vaccination. Obesity impacts millions globally, and greater understanding of its associated physiological disturbances is a key public health concern.
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206
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Uner AG, Sulu N. In vivo effects of leptin on lymphocyte subpopulations in mice. Immunobiology 2012; 217:882-8. [PMID: 22317748 DOI: 10.1016/j.imbio.2011.12.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Revised: 12/22/2011] [Accepted: 12/29/2011] [Indexed: 11/18/2022]
Abstract
Leptin, a hormone-cytokine mainly produced by the adipose tissue, has pleitropic effects on many biological system including metabolic, endocrine, and immune system. Although it is well known that leptin controls food intake on hypothalamic regions of brain, the role of leptin in hematopoietic and immune processes has been mainly investigated with in vitro and transgenic mouse studies. The aim of this study was to investigate the effects of peripheral leptin on lymphocyte subpopulation. Initially forty male Swiss albino mice were divided into five groups. Mice in group I (Control) were given serum physiologic (SP) and group L100, group L250, group L500, and group L1000 were given 100, 250, 500 and 1000 μg/kg/day recombinant mouse leptin, respectively. Leptin or SP was injected subcutaneously for the next 6 days. Daily food/water intake was recorded for each group. At the end of the study, whole blood samples (500 μl) were obtained via intracardiac punction in anesthetized mice. Leptin levels and lymphocyte subpopulations in blood samples were analyzed. We show that no in vivo dose-dependent effect of leptin is existed on lymphocyte subpopulations count in mice. Treatment of mice with high-dose leptin led to increase only CD4+ cells (P<0.05). In addition, high-dose leptin slightly increased CD3+ cells but this was not statistically confirmed (P=0.08). Notably, it was found that leptin caused insignificant changes on body weight and food intake in normal body weight mice. The data support that high-dose leptin has proliferative effect on CD4+ cells in vivo. However, more in vivo study needs to be examined to clarify how leptin affect lymphocyte subpopulations.
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Affiliation(s)
- Aykut G Uner
- Department of Physiology, Adnan Menderes University, Aydin, Turkey.
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207
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Silverberg JI, Silverberg NB, Lee-Wong M. Association between atopic dermatitis and obesity in adulthood. Br J Dermatol 2012; 166:498-504. [PMID: 21999468 DOI: 10.1111/j.1365-2133.2011.10694.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Obesity in early childhood is associated with increased risk for and severity of atopic dermatitis (AD). Objective To determine whether obesity in adulthood is associated with risk of AD. METHODS This was a retrospective case-control study of 2090 adults using questionnaire, height and weight, and skin-prick testing between January 1994 and December 2003. RESULTS Obesity in adults was associated with increased AD [multinomial logistic regression: adjusted odds ratio (aOR) 1·43, 95% confidence interval (CI) 1·08-1·89; P=0·01], but not nonatopic dermatitis (aOR 0·59, 95% CI 0·21-1·68; P=0·32). Obesity was also associated with increased atopic asthma (aOR 1·98, 95% CI 1·47-2·66, P<0·0001), but not associated with nonatopic asthma (P=0·20), atopic or nonatopic rhinoconjunctivitis (P=0·08 and 0·31, respectively), food allergies (P=0·67 and 0·35, respectively) or atopy (P=0·40). The association between obesity and AD remained significant even when controlling for history of asthma, rhinoconjunctivitis and food allergies (aOR 1·40, 95% CI 1·05-1·86; P=0·02) or in subset analyses of subjects with AD alone (aOR 1·96, 95% CI 1·02-3·75; P=0·04) and with comorbid asthma, rhinoconjunctivitis and/or food allergies (aOR 1·40, 95% CI 1·03-1·91; P=0·03). CONCLUSION Obesity in adulthood is associated with AD. Further studies are warranted to determine if weight loss may prevent or mitigate AD in adults.
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Affiliation(s)
- J I Silverberg
- Department of Dermatology, St Luke's-Roosevelt Hospital and Beth Israel Medical Centers, New York, NY 10025, USA.
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208
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Wrann CD, Laue T, Hübner L, Kuhlmann S, Jacobs R, Goudeva L, Nave H. Short-term and long-term leptin exposure differentially affect human natural killer cell immune functions. Am J Physiol Endocrinol Metab 2012; 302:E108-16. [PMID: 21952038 DOI: 10.1152/ajpendo.00057.2011] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Epidemiological studies have indicated that obesity is associated with a higher risk for certain cancers caused by elevated levels of adipocyte-derived hormones. Leptin, one such hormone produced by adipocytes, is a major regulator of metabolism and has also been shown to modulate immunity. However, its role in regulating human natural killer (NK) cell functions is largely unknown. Here, we show that the leptin receptor (Ob-R) is expressed on 5% of NK cells isolated from blood donors, as measured with flow cytometry, and expression of the signal-transducing long form of the leptin receptor Ob-Rb was confirmed with quantitative PCR. The Ob-R+ subpopulation displayed a lower expression of CD16, a cell surface receptor mediating antibody-dependent activation. Short-term stimulation with leptin increased IFNγ secretion, CD69 activation marker expression, and cytotoxic lysis of tumor cells; this was mediated by an improved conjugate forming between NK cells and tumor cells as well as higher expression of tumor necrosis factor-related apoptosis-inducing ligand. On the contrary, long-term incubation with leptin significantly impaired these NK cell immune functions and decreased cell proliferation. In addition, phosphorylation of Jak-2 after leptin stimulation was reduced in peripheral mononuclear blood cells from obese humans compared with normal-weight controls. NK cells represent an immune cell population that is crucial for an effective antitumor response. Here, we show that long-term exposure to leptin, similarly to the situation in obese individuals with elevated serum leptin levels, significantly impairs integral parts of NK cell immune functions, possibly linking leptin to increased cancer susceptibility in obesity.
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Affiliation(s)
- Christiane D Wrann
- Div. of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, USA.
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209
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D'Ippolito S, Tersigni C, Scambia G, Di Simone N. Adipokines, an adipose tissue and placental product with biological functions during pregnancy. Biofactors 2012; 38:14-23. [PMID: 22287297 DOI: 10.1002/biof.201] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Accepted: 12/28/2011] [Indexed: 01/03/2023]
Abstract
Latter half of pregnancy is characterized by a "physiological diabetogenic state" since changes in insulin-sensitivity have been well documented. These changes ensure continuous supply of nutrients to the growing fetus. In the last years the role of adipocyte-derived signaling molecules, collectively known as adipokines has been object of different in vitro and in vivo studies. Of interest, adipokines and/or their receptors are expressed in the placental tissue which, therefore, can contribute to development of maternal insulin-resistance and, as a consequence, fetal growth. Leptin, adiponectin, and resistin represent the most well studied adipokines and, with the exception of adiponectin, their serum and placental levels increase as pregnancy progresses. High levels of adipokines have also been detected in umbilical plasma hence suggesting a possible role on fetal development and metabolism; however, it remains still unclear if such adipokines can directly stimulate fetal tissues development acting as growth factors. In addition to their well known metabolic effects, we also reported studies describing the role of adipokines in promoting proliferation and invasiveness of trophoblast cells and affecting local angiogenic processes. These observations strongly suggest that adipokines, by alternatively interfering with placental development, may affect pregnancy outcome and fetal growth. However, further studies are needed to better understand the local regulation of their expression. © 2012 International Union of Biochemistry and Molecular Biology, Inc.
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Affiliation(s)
- Silvia D'Ippolito
- Department of Obstetrics and Gynecology, Policlinico A. Gemelli, Università Cattolica del Sacro Cuore, Rome, Italy
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210
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Jia Z, Zhang J, Wu Z, Tian J. Leptin Enhances Maturation and Development of Calf Oocytes In vitro. Reprod Domest Anim 2011; 47:718-23. [DOI: 10.1111/j.1439-0531.2011.01949.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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211
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Procaccini C, Jirillo E, Matarese G. Leptin as an immunomodulator. Mol Aspects Med 2011; 33:35-45. [PMID: 22040697 DOI: 10.1016/j.mam.2011.10.012] [Citation(s) in RCA: 210] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 10/12/2011] [Accepted: 10/14/2011] [Indexed: 10/15/2022]
Abstract
Leptin is an adipocyte-derived hormone/cytokine that links nutritional status with neuroendocrine and immune functions. In humans, leptin influences energy homeostasis and regulates neuroendocrine function primarily in states of energy deficiency. Initially described as an antiobesity hormone, leptin has subsequently been shown also to influence basal metabolism, hematopoiesis, thermogenesis, reproduction, and angiogenesis. As a cytokine, leptin can affect thymic homeostasis and the secretion of acute-phase reactants such as interleukin-1 (IL-1) and tumor-necrosis factor-alpha (TNF-α). Leptin links nutritional status and proinflammatory T helper 1 (Th1) immune responses and the decrease in leptin plasma concentration during food deprivation leads to impaired immune function. Similar to other pro-inflammatory cytokines, leptin promotes Th1-cell differentiation and can modulate the onset and progression of autoimmune responses in several animal models of disease. Here, we review the advances and controversy for a role of leptin in the pathophysiology of immune responses and discuss novel possible therapeutic implications for leptin modulators.
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Affiliation(s)
- Claudio Procaccini
- Laboratorio di Immunologia, Istituto di Endocrinologia e Oncologia Sperimentale, Consiglio Nazionale delle Ricerche, c/o Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università di Napoli, Federico II, Via Pansini 5, 80131 Napoli, Italy
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212
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Pereira M, Vidotti DB, Borra RC, Simões MDJ, Da Silva IDCG, Haidar MA. Involvement of GDF-9, leptin, and IGF1 receptors associated with adipose tissue transplantation on fertility restoration in obese anovulatory mice. Gynecol Endocrinol 2011; 27:759-66. [PMID: 21557698 DOI: 10.3109/09513590.2010.534330] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The aim was to analyze the effect of adipose tissue transplantation on growth differentiation factor-9 (GDF-9), insulin growth factor 1 receptor (IGF1R), and leptin receptor (LEPR) protein expression in ovaries of obese anovulatory mice. Leptin-deficient female (ob/ob) and wild-type mice were divided into untreated ob/ob mice and gonadal white adipose tissue transplanted ob/ob mice, with evaluation after 7, 15, and 45 days and compared to control wild-type mice. The corporal weight and glycemia levels increased in the obese group concomitant with polymicrocyst formation and abundant estrone, mimicking anovulatory disease. In the treated group after 45 days, glycemia, weight, ovarian size, and number of follicles were decreased and corpora lutea were decreased. The analysis of GDF-9 revealed that, whereas control ovaries presented follicular localization, the obese ovary lacked this protein. On the other hand, obese ovaries showed elevated expression of IGF1R that was normalized after the transplantation. Finally, LEPR was reduced in obese ovaries, and adipose tissue transplantation was efficient in returning it to normal levels. In conclusion, the adipose tissue transplantation, especially after 45 days, seems to stimulate ovulation, supported by the fact that several proteins involved in ovulation returned to basal levels.
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Affiliation(s)
- Melquíades Pereira
- Department of Gynecology, Federal University of São Paulo, São Paulo, Brazil
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213
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Koethe JR, Jenkins CA, Shepherd BE, Stinnette SE, Sterling TR. An optimal body mass index range associated with improved immune reconstitution among HIV-infected adults initiating antiretroviral therapy. Clin Infect Dis 2011; 53:952-60. [PMID: 21946189 DOI: 10.1093/cid/cir606] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Higher body mass index (BMI) was associated with slower human immunodeficiency virus (HIV) disease progression before the availability of effective antiretroviral therapy (ART), but the relationship between pretreatment BMI and CD4(+) lymphocyte recovery on ART is not well described. METHODS We conducted an observational cohort study of HIV-infected, ART-naive adults starting treatment at a clinic affiliated with Vanderbilt University in Nashville, Tennessee. We assessed the relationship between pretreatment BMI and CD4(+) lymphocyte count change from baseline to 12 months in all subjects, among those with plasma HIV-1 RNA levels <400 copies/mL for ≥ 6 months and those with <10% change in weight during follow-up. Linear regression models were adjusted for age, sex, race, protease inhibitor usage, year of ART initiation, and baseline CD4(+) lymphocyte count and HIV-1 RNA level. RESULTS A total of 915 patients met inclusion criteria; 78% were male, and their median age, BMI, and CD4(+) lymphocyte count were 39 years, 24 kg/m², and 171 cells/μL, respectively. The CD4(+) lymphocyte increase at 12 months was greatest among patients with a pretreatment BMI of ~25-30 kg/m² and diminished above and below this range (P = .03). Similar patterns were observed in the subgroup analyses. Among patients with a pretreatment CD4(+) lymphocyte count < 200 cells/μL, a BMI of ~25 kg/m² was associated with the highest odds of reaching a CD4(+) lymphocyte count > 350 cells/μL at 12 months (P = .05). CONCLUSIONS 12-month immune reconstitution on ART was highest among patients commonly classified as overweight, suggesting there may be an optimal BMI range for immune recovery on ART.
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Affiliation(s)
- John R Koethe
- Department of Medicine, Division of Infectious Diseases, Center for Health Services Research, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
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214
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Molvarec A, Szarka A, Walentin S, Bekő G, Karádi I, Prohászka Z, Rigó Jr J. Serum leptin levels in relation to circulating cytokines, chemokines, adhesion molecules and angiogenic factors in normal pregnancy and preeclampsia. Reprod Biol Endocrinol 2011; 9:124. [PMID: 21906313 PMCID: PMC3184629 DOI: 10.1186/1477-7827-9-124] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 09/09/2011] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVE In this study, we determined circulating levels of C-reactive protein, several cytokines, chemokines, adhesion molecules and angiogenic factors along with those of leptin in healthy non-pregnant and pregnant women and preeclamptic patients, and investigated whether serum leptin levels were related to the clinical characteristics and measured laboratory parameters of the study participants. METHODS Sixty preeclamptic patients, 60 healthy pregnant women and 59 healthy non-pregnant women were involved in this case-control study. Levels of leptin and transforming growth factor (TGF)-beta1 in maternal sera were assessed by ELISA. Serum levels of interleukin (IL)-1beta, IL-1 receptor antagonist (IL-1ra), IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p40, IL-12p70, IL-18, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interferon-gamma-inducible protein (IP)-10, monocyte chemotactic protein (MCP)-1, intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 were determined by multiplex suspension array. Serum C-reactive protein (CRP) concentrations were measured by an autoanalyzer. Serum total soluble fms-like tyrosine kinase-1 (sFlt-1) and biologically active placental growth factor (PlGF) levels were determined by electrochemiluminescence immunoassay. For statistical analyses, non-parametric methods were applied. RESULTS There were significant differences in most of the measured laboratory parameters among the three study groups except for serum IL-1beta and TGF-beta1 levels. Serum leptin levels were significantly higher in preeclamptic patients and healthy pregnant women than in healthy non-pregnant women. Additionally, preeclamptic patients had significantly higher leptin levels as compared to healthy pregnant women. Serum leptin levels were independently associated with BMI in healthy non-pregnant women. In healthy pregnant women, both BMI and serum CRP concentrations showed significant positive linear association with leptin levels. There were significant positive correlations between serum leptin concentrations of healthy pregnant women and systolic blood pressure, as well as serum levels of IP-10, while their serum leptin levels correlated inversely with fetal birth weight. In preeclamptic patients, a significant positive correlation was observed between serum concentrations of leptin and IP-10. Furthermore, elevated serum leptin level and sFlt-1/PlGF ratio had an additive (joint) effect in the risk of preeclampsia, as shown by the substantially higher odds ratios of their combination than of either alone. CONCLUSIONS Simultaneous measurement of leptin with several inflammatory molecules and angiogenic factors in this study enabled us to investigate their relationship, which can help to understand the role of circulating leptin in normal pregnancy and preeclampsia.
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Affiliation(s)
- Attila Molvarec
- First Department of Obstetrics and Gynecology, Semmelweis University, Budapest, Hungary
| | - András Szarka
- First Department of Obstetrics and Gynecology, Semmelweis University, Budapest, Hungary
| | - Szilvia Walentin
- Central Laboratory, Kútvölgyi Clinical Center, Semmelweis University, Budapest, Hungary
| | - Gabriella Bekő
- Department of Laboratory Medicine, Semmelweis University, Budapest, Hungary
| | - István Karádi
- Third Department of Internal Medicine, Semmelweis University, Budapest, Hungary
| | - Zoltán Prohászka
- Third Department of Internal Medicine, Semmelweis University, Budapest, Hungary
- Research Group of Inflammation Biology and Immunogenomics, Hungarian Academy of Sciences, Budapest, Hungary
| | - János Rigó Jr
- First Department of Obstetrics and Gynecology, Semmelweis University, Budapest, Hungary
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215
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Role of leptin in human visceral leishmaniasis? Med Hypotheses 2011; 77:416-8. [DOI: 10.1016/j.mehy.2011.05.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 05/29/2011] [Indexed: 01/26/2023]
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216
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Arnaud C, Beguin PC, Lantuejoul S, Pepin JL, Guillermet C, Pelli G, Burger F, Buatois V, Ribuot C, Baguet JP, Mach F, Levy P, Dematteis M. The inflammatory preatherosclerotic remodeling induced by intermittent hypoxia is attenuated by RANTES/CCL5 inhibition. Am J Respir Crit Care Med 2011; 184:724-31. [PMID: 21680945 DOI: 10.1164/rccm.201012-2033oc] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE The highly prevalent obstructive sleep apnea syndrome (OSA) with its main component intermittent hypoxia (IH) is a risk factor for cardiovascular mortality. The poor knowledge of its pathophysiology has limited the development of specific treatments, whereas the gold standard treatment, continuous positive airway pressure, may not fully reverse the chronic consequences of OSA and has limited acceptance in some patients. OBJECTIVES To examine the contribution of IH-induced inflammation to the cardiovascular complications of OSA. METHODS We investigated systemic and vascular inflammatory changes in C57BL6 mice exposed to IH (21-5% Fi(O(2)), 60-s cycle) or normoxia 8 hours per day up to 14 days. Vascular alterations were reassessed in mice treated with a blocking antibody of regulated upon activation, normal T-cell expressed and secreted (RANTES)/CC chemokine ligand 5 (CCL5) signaling pathway, or with the IgG isotype control throughout the IH exposure. MEASUREMENTS AND MAIN RESULTS IH induced systemic inflammation combining increased splenic lymphocyte proliferation and chemokine expression, with early and predominant RANTES/CCL5 alterations, and enhanced splenocyte migration toward RANTES/CCL5. IH also induced structural and inflammatory vascular alterations. Leukocyte-endothelium adhesive interactions were increased, attested by leukocyte rolling and intercellular adhesion molecule-1 expression in mesenteric vessels. Aortas had increased intima-media thickness with elastic fiber alterations, mucoid depositions, nuclear factor-κB-p50 and intercellular adhesion molecule-1 overexpression, hypertrophy of smooth-muscle cells overexpressing RANTES/CCL5, and adventitial-periadventitial T-lymphocyte infiltration. RANTES/CCL5 neutralization prevented both intima-media thickening and inflammatory alterations, independently of the IH-associated proatherogenic dyslipidemia. CONCLUSIONS Inflammation is a determinant mechanism for IH-induced preatherosclerotic remodeling involving RANTES/CCL5, a key chemokine in atherogenesis. Characterization of the inflammatory response could allow identifying at-risk patients for complications, and its pharmacologic manipulation may represent a potential complementary treatment of sleep apnea consequences.
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Successful modulation of type 2 diabetes in db/db mice with intra-bone marrow--bone marrow transplantation plus concurrent thymic transplantation. J Autoimmun 2011; 35:414-23. [PMID: 20884174 DOI: 10.1016/j.jaut.2010.09.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2010] [Revised: 09/02/2010] [Accepted: 09/03/2010] [Indexed: 12/29/2022]
Abstract
There is increasing evidence that both autoimmune and autoinflammatory mechanisms are involved in the development of not only type 1 diabetes mellitus (T1 DM), but also type 2 diabetes mellitus (T2 DM). Our laboratory has focused on this concept, and in earlier efforts replaced the bone marrow cells (BMCs) of leptin receptor-deficient (db/db) mice, an animal model of T2DM, with those of normal C57BL/6 (B6) mice by IBM-BMT. However, the outcome was poor due to incomplete recovery of T cell function. Therefore, we hypothesized that intra-bone marrow-bone marrow transplantation plus thymus transplantation (IBM-BMT + TT) could be used to treat T2 DM by normalizing the T cell imbalance. Hence we addressed this issue by using such dual transplantation and demonstrate herein that seven weeks later, recipient db/db mice manifested improved body weight, reduced levels of blood glucose, and a reduction of plasma IL-6 and IL-1β. More importantly, this treatment regimen showed normal CD4/CD8 ratios, and increased plasma adiponectin levels, insulin sensitivity, and the number of insulin-producing cells. Furthermore, the expression of pancreatic pAKT, pLKB1, pAMPK and HO-1 was increased in the mice treated with IBM-BMT + TT. Our data show that IBM-BMT + TT treatment normalizes T cell subsets, cytokine imbalance and insulin sensitivity in the db/db mouse, suggesting that IBM-BMT + TT is a viable therapeutic option in the treatment of T2 DM.
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218
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Hwang SJ, Kim JH, Shim JW, Kim DS, Jung HL, Park MS, Lee WY, Kim SY, Shim JY. Peroxisome proliferator-activated receptor-gamma expression in the lung tissue of obese rats. Yonsei Med J 2011; 52:495-501. [PMID: 21488194 PMCID: PMC3101042 DOI: 10.3349/ymj.2011.52.3.495] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
PURPOSE Obesity is a risk factor for asthma and type II diabetes. Peroxisome proliferator- activated receptor (PPAR)-γ has been suggested to regulate inflammatory responses in diabetes and asthma. We investigated whether PPAR-α, PPAR-γ, adiponectin receptors (AdipoR1, AdipoR2), leptin, and tumor necrosis factor (TNF)-α are expressed in rat lung tissues and whether the expression differs between obese Otsuka Long-Evans Tokushima Fatty (OLETF) and lean Long Evans Tokushima Otsuka (LETO) rats. MATERIALS AND METHODS Obese and lean rats were given with a high fat diet or a 30% restricted diet for 32 weeks, and their blood glucose levels and weights were monitored. After 32 weeks, mRNA levels of PPAR-α, PPAR-γ, AdipoR1, AdipoR2, leptin, and TNF-α in lung tissues were measured using real time PCR. RESULTS PPAR-α, PPAR-γ, AdipoR1, AdipoR2, leptin, and TNF-α were expressed in both obese and lean rat lung tissues. Increased serum glucose levels on intraperitoneal glucose tolerance testing and a higher weight gain at 32 weeks were observed in OLETF control rats compared to OLETF diet restricted rats. PPAR-γ expression was markedly elevated in obese control and diet restricted rats compared to lean rats, although PPAR-γ expression in obese rats was not affected by diet restriction. Leptin was highly expressed in OLETF rats compared to LETO rats. TNF-α expression was enhanced in OLETF control rats compared LETO diet restricted rats, and decreased by diet restriction. PPAR-α, AdipoR1, and AdipoR2 expression were not significantly different between obese and lean rats. CONCLUSION PPAR-γ was highly expressed in the lung tissues of obese rats and may be a novel treatment target for regulating lung inflammation associated with obesity.
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Affiliation(s)
- Su Jin Hwang
- Department of Pediatrics, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jung Ho Kim
- Department of Pediatrics, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jae Won Shim
- Department of Pediatrics, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Duk Soo Kim
- Department of Pediatrics, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hye Lim Jung
- Department of Pediatrics, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Moon Soo Park
- Department of Pediatrics, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Won Young Lee
- Department of Endocrinology and Metabolism, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Se-Yeon Kim
- Research Institute of Medical Science, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jung Yeon Shim
- Department of Pediatrics, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
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Guo X, Roberts MR, Becker SM, Podd B, Zhang Y, Chua SC, Myers MG, Duggal P, Houpt ER, Petri WA. Leptin signaling in intestinal epithelium mediates resistance to enteric infection by Entamoeba histolytica. Mucosal Immunol 2011; 4:294-303. [PMID: 21124310 PMCID: PMC3079783 DOI: 10.1038/mi.2010.76] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Leptin is an adipocytokine that links nutrition to immunity. Previous observation that a genetic polymorphism in the leptin receptor affected susceptibility to Entamoeba histolytica infection led to the hypothesis that leptin signaling has a protective role during intestinal amebic infection. In this study we show that mice lacking the functional leptin receptor developed devastating mucosal destruction after E. histolytica infection. Bone marrow chimera experiments demonstrated that leptin receptor expressed on hematopoietic cells was not sufficient to confer resistance. Similarly, peripheral knockout of the leptin receptor rendered animals susceptible, indicating that central expression of the leptin receptor was not sufficient to confer protection. The site of leptin action was localized to the gut via an intestinal epithelium-specific deletion of the leptin receptor, which rendered mice susceptible to infection and mucosal destruction by the parasite. Mutation of tyrosine 985 or 1138 in the intracellular domain of the leptin receptor, which mediates signaling through the SH2-containing tyrosine phosphatase/extracellular signal-regulated kinase (SHP2/ERK) and signal transducer and activator of transcription 3 (STAT3) pathways, respectively, demonstrated that both were important for mucosal protection. We conclude that leptin-mediated resistance to amebiasis is via its actions on intestinal epithelium rather than hematopoietic cells or the brain, and requires leptin receptor signaling through both the STAT3 and SHP2/ERK pathways.
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Affiliation(s)
- Xiaoti Guo
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia
| | - Margo R. Roberts
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia
| | - Stephen M. Becker
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia
| | - Bradley Podd
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia
| | - Yiying Zhang
- Department of Pediatrics, Division of Molecular Genetics & Naomi Berrie Diabetes Center Columbia University Medical Center, New York, New York
| | - Streamson C. Chua
- Departments of Medicine and Neuroscience, Albert Einstein College of Medicine, Bronx, New York
| | - Martin G. Myers
- Departments of Internal Medicine & Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Priya Duggal
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Eric R. Houpt
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia.,Corresponding Authors: William A. Petri, Jr., Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, VA, 434 924 5621 (direct), 434 924 0075 (fax) , *Eric R. Houpt, Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, VA, 434 243 9326 (direct), 434 924 0075 (fax)
| | - William A. Petri
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia
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Conde J, Scotece M, Gómez R, Gómez-Reino JJ, Lago F, Gualillo O. At the crossroad between immunity and metabolism: focus on leptin. Expert Rev Clin Immunol 2011; 6:801-8. [PMID: 20828288 DOI: 10.1586/eci.10.48] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
White adipose tissue is currently considered to be an active endocrine organ that secretes a plethora of factors named adipokines, most of them proinflammatory in nature, which probably contribute to low-level systemic inflammation; a state that is often present in metabolic syndrome-associated chronic pathologies such as obesity and atherosclerosis. Leptin is historically and indisputably one of the most important adipokines secreted by fat cells, with a variety of physiological roles related to the control of metabolism, energy homeostasis and inflammatory response. One of these functions is the connection between nutritional status and immune competence. Indeed, leptin has been shown to modulate both the innate and adaptive immune responses in both normal and pathological conditions. It has been shown that conditions characterized by low leptin levels are associated with increased susceptibility to infection. Conversely, immune-mediated disorders, such as autoimmune diseases, are associated with increased secretion of leptin and the production of proinflammatory pathogenic cytokines. Thus, leptin can easily be considered a frank mediator of the inflammatory/immune response.
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Affiliation(s)
- Javier Conde
- Research laboratory 9 (NEIRID LAB: Neuroendocrine Interactions in Rheumatology and Inflammation Disease), Building C, Level -2, Institute of Medical Research (IDIS), Santiago University Clinical Hospital, Calle Choupana s/n, Santiago de Compostela, 15706, Spain.
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Akbar M, Brewer JM, Grant MH. Effect of chromium and cobalt ions on primary human lymphocytesin vitro. J Immunotoxicol 2011; 8:140-9. [DOI: 10.3109/1547691x.2011.553845] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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Suzukawa M, Nagase H, Ogahara I, Han K, Tashimo H, Shibui A, Koketsu R, Nakae S, Yamaguchi M, Ohta K. Leptin enhances survival and induces migration, degranulation, and cytokine synthesis of human basophils. THE JOURNAL OF IMMUNOLOGY 2011; 186:5254-60. [PMID: 21421855 DOI: 10.4049/jimmunol.1004054] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Basophils are the rarest leukocytes in human blood, but they are now recognized as one of the most important immunomodulatory as well as effector cells in allergic inflammation. Leptin, a member of the IL-6 cytokine family, has metabolic effects as an adipokine, and it is also known to participate in the pathogenesis of inflammatory reactions. Because there is an epidemiologic relationship between obesity and allergy, we examined whether basophil functions are modified by leptin. We found that human basophils express leptin receptor (LepR) at both the mRNA and surface protein levels, which were upregulated by IL-33. Leptin exerted strong effects on multiple basophil functions. It induced a strong migratory response in human basophils, similar in potency to that of basophil-active chemokines. Also, leptin enhanced survival of human basophils, although its potency was less than that of IL-3. Additionally, CD63, a basophil activation marker expressed on the cell surface, was upregulated by leptin, an effect that was neutralized by blocking of LepR. Assessments of basophil degranulation and cytokine synthesis found that leptin showed a strong priming effect on human basophil degranulation in response to FcεRI aggregation and induced Th2, but not Th1, cytokine production by the cells. In summary, the present findings indicate that leptin may be a key molecule mediating the effects of adipocytes on inflammatory cells such as basophils by binding to LepR and activating the cellular functions, presumably exacerbating allergic inflammation.
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Affiliation(s)
- Maho Suzukawa
- Division of Respiratory Medicine and Allergology, Department of Medicine, Teikyo University School of Medicine, Itabashi-ku, Tokyo 173-8605, Japan.
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Silverberg JI, Kleiman E, Lev-Tov H, Silverberg NB, Durkin HG, Joks R, Smith-Norowitz TA. Association between obesity and atopic dermatitis in childhood: a case-control study. J Allergy Clin Immunol 2011; 127:1180-6.e1. [PMID: 21411132 DOI: 10.1016/j.jaci.2011.01.063] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 01/17/2011] [Accepted: 01/21/2011] [Indexed: 11/19/2022]
Abstract
BACKGROUND Obesity in children is associated with increased asthma and atopy. OBJECTIVE We sought to determine whether obesity in childhood or adolescence increases the risk of atopic dermatitis. METHODS This retrospective, practice-based, case-control study randomly sampled 414 children and adolescents (age, 1-21 years) with atopic dermatitis between January 2000 and December 2007 and 828 randomly sampled healthy control subjects. Information was obtained from an electronic medical record. Observations were made before the a priori hypothesis. RESULTS Obesity in children is associated with increased atopic dermatitis (conditional logistic regression: odds ratio, 2.00; 95% CI, 1.22-3.26; P = .006). These atopic dermatitis-predisposing effects are found when obesity started by less than 2 years of age (adjusted odds ratio [aOR], 15.10; 95% CI, 1.51-151.21; P = .02) and 2 to 5 years (aOR, 2.58; 95% CI, 1.24-5.41; P = .01) but not greater than 5 years (aOR, 1.32; 95% CI, 0.66-2.64; P = .43) and when obesity was prolonged for 2.5 to 5 years (aOR, 2.64; 95% CI, 1.13-6.18; P = .03) and greater than 5 years (aOR, 3.40; 95% CI, 1.34-8.63; P = 0.01). Obesity is associated with more severe atopic dermatitis (ordinal logistic regression: aOR, 2.37; 95% CI, 1.24-5.37; P = .01). Obese children who eventually have atopic dermatitis require more frequent pediatrician visits for the management of atopic dermatitis (ordinal logistic regression: aOR, 2.22; 95% CI, 1.12-4.50; P = .03). CONCLUSION Prolonged obesity in early childhood is a risk factor for atopic dermatitis. Weight loss might be an important approach for the prevention and treatment of atopic dermatitis in children.
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Affiliation(s)
- Jonathan I Silverberg
- Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, NY, USA.
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Gorska E, Popko K, Stelmaszczyk-Emmel A, Ciepiela O, Kucharska A, Wasik M. Leptin receptors. Eur J Med Res 2011; 15 Suppl 2:50-4. [PMID: 21147620 PMCID: PMC4360333 DOI: 10.1186/2047-783x-15-s2-50] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Leptin or obesity receptor (Ob-R) is a member of class I cytokine receptor family. Ob-R, expressed in six isoforms, is the product of alternative RNA splicing of db gene. According to its structural differences, the receptor's isoforms are divided into three classes: long, short, and secretory isoforms. A long, fully active isoform of Ob-Rb is expressed mainly in the hypothalamus, where it takes part in energy homeostasis and in the regulation of secretory organs' activity. Ob-Rb is also present on all types of immune cells, involved in innate and adaptive immunity. Short leptin isoforms (Ob-Ra, Ob-Rc, Ob-Rd, and Ob-Re) that contain box 1 motif are able to bind JAK kinases (Janus kinases) as well as to activate some other signal transduction cascades. A soluble isoform (Ob-Re) can regulate serum leptin concentration and serve as a carrier protein delivering the hormone to its membrane receptors and is able to transduce the signal into the cell. JAK/STAT pathway plays the major role in leptin signal transduction through membrane receptors. Among all Ob-R isoforms, only full-length isoform (Ob-Rb) is able to fully transduce activation signal into the cell.
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Affiliation(s)
- Elzbieta Gorska
- Department of Laboratory Diagnostics, Warsaw Medical University, Warsaw, Poland.
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225
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Abstract
A growing body of literature suggests multifaceted alterations to the immune function in obese patients compared with a lean cohort. Although treatment in the intensive care unit has an associated risk of infectious complications, which, if any, of these immunologic alterations are causal is unclear. Obesity clearly causes abundant alterations to the immune system. Overall, the aggregate effect seems to be chronic activation of inflammatory mediators.
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Affiliation(s)
- Mitchell K Craft
- Division of Critical Care Medicine, Geisinger Medical Center, 100 North Academy Avenue, Danville, PA 17822, USA
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226
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Jain M, Budinger GRS, Lo A, Urich D, Rivera SE, Ghosh AK, Gonzalez A, Chiarella SE, Marks K, Donnelly HK, Soberanes S, Varga J, Radigan KA, Chandel NS, Mutlu GM. Leptin promotes fibroproliferative acute respiratory distress syndrome by inhibiting peroxisome proliferator-activated receptor-γ. Am J Respir Crit Care Med 2011; 183:1490-8. [PMID: 21317313 DOI: 10.1164/rccm.201009-1409oc] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
RATIONALE Diabetic patients have a lower incidence of acute respiratory distress syndrome (ARDS), and those who develop ARDS are less likely to die. The mechanisms that underlie this protection are unknown. OBJECTIVES To determine whether leptin resistance, a feature of diabetes, prevents fibroproliferation after lung injury. METHODS We examined lung injury and fibroproliferation after the intratracheal instillation of bleomycin in wild-type and leptin-resistant (db/db) diabetic mice. We examined the effect of leptin on transforming growth factor (TGF)-β(1)-mediated transcription in primary normal human lung fibroblasts. Bronchoalveolar lavage fluid (BAL) samples from patients with ARDS and ventilated control subjects were obtained for measurement of leptin and active TGF-β(1) levels. MEASUREMENTS AND MAIN RESULTS Diabetic mice (db/db) were resistant to lung fibrosis. The db/db mice had higher levels of peroxisome proliferator-activated receptor-γ (PPARγ), an inhibitor of the transcriptional response to TGF-β(1), a cytokine critical in the pathogenesis of fibroproliferative ARDS. In normal human lung fibroblasts, leptin augmented the transcription of profibrotic genes in response to TGF-β(1) through a mechanism that required PPARγ. In patients with ARDS, BAL leptin levels were elevated and correlated with TGF-β(1) levels. Overall, there was no significant relationship between BAL leptin levels and clinical outcomes; however, in nonobese patients, higher BAL leptin levels were associated with fewer intensive care unit- and ventilator-free days and higher mortality. CONCLUSIONS Leptin signaling is required for bleomycin-induced lung fibrosis. Leptin augments TGF-β(1) signaling in lung fibroblasts by inhibiting PPARγ. These findings provide a mechanism for the observed protection against ARDS observed in diabetic patients.
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Affiliation(s)
- Manu Jain
- Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
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Sánchez-Jiménez F, Pérez-Pérez A, González-Yanes C, Najib S, Varone CL, Sánchez-Margalet V. Leptin receptor activation increases Sam68 tyrosine phosphorylation and expression in human trophoblastic cells. Mol Cell Endocrinol 2011; 332:221-7. [PMID: 21035519 DOI: 10.1016/j.mce.2010.10.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 09/27/2010] [Accepted: 10/19/2010] [Indexed: 10/18/2022]
Abstract
Leptin is produced in placenta where it has been found to be an important autocrine signal for trophoblastic growth during pregnancy, promoting antiapoptotic and trophic effects. Leptin receptor is present in trophoblastic cells and leptin may fully activate signaling. We have previously implicated the RNA-binding protein Sam68 in leptin signal transduction in immune cells. In the present work, we have studied the possible role of Sam68 in leptin receptor signaling in trophoblastic cells (JEG-3 cells). Leptin dose-dependently stimulated Sam68 phosphorylation in JEG-3 cells, as assessed by immunoprecipitation and immunoblot with anti-phosphotyrosine antibodies. As previously observed in other systems, tyrosine phosphorylation of Sam68 in response to leptin inhibits its RNA binding capacity. Besides, leptin stimulation dose-dependently increases Sam68 expression in JEG-3 cells, as assessed by quantitative PCR. Consistently, the amount of Sam68 protein is increased after 24h of leptin stimulation of trophoblastic cells. In order to study the possible role of Sam68 on leptin receptor synthesis, we employed antisense strategy to knockdown the expression of Sam68. We have found that a decrease in Sam68 expression leads to a decrease in leptin receptor amount in JEG-3 cells, as assessed both by quantitative PCR and immunoblot. These results strongly suggest the participation of Sam68 in leptin receptor signaling in human trophoblastic cells, and therefore, Sam68 may mediate some of the leptin effects in placenta.
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Affiliation(s)
- Flora Sánchez-Jiménez
- Department of Clinical Biochemistry, Virgen Macarena University Hospital, University of Seville, Av Dr Fedriani 3, Seville 41071, Spain
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Leptin activates human B cells to secrete TNF-α, IL-6, and IL-10 via JAK2/STAT3 and p38MAPK/ERK1/2 signaling pathway. J Clin Immunol 2011; 31:472-8. [PMID: 21243519 PMCID: PMC3132280 DOI: 10.1007/s10875-010-9507-1] [Citation(s) in RCA: 175] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Accepted: 12/30/2010] [Indexed: 11/08/2022]
Abstract
Leptin, one of the adipokines, functions as a hormone and a cytokine. In this investigation, we show for the first time that leptin, in a concentration-dependent manner, activates human peripheral blood B cells to induce secretion of IL-6, IL-10, and TNF-α. Leptin increased B cells expressing CD25 and HLA-DR. Leptin induces phosphorylation of Janus activation kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), p38 mitogen-activated protein kinase (p38MAPK), and extracellular signal-regulated kinase (ERK1/2). Furthermore, leptin-induced cytokine secretion by B cells was blocked by inhibitors of JAK2, STAT3, p38MAPK, and ERK1/2. These data demonstrate that leptin activates human B cells to secrete cytokines via activation of JAK2/STAT3 and p38MAPK/ERK1/2 signaling pathways, which may contribute to its inflammatory and immunoregulatory properties.
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Airaghi L, Usardi P, Forti S, Orsatti A, Baldini M, Annaloro C, Lambertenghi Deliliers G. A comparison between metabolic syndrome post-hematopoietic stem cell transplantation and spontaneously occurring metabolic syndrome. J Endocrinol Invest 2011; 34:e6-11. [PMID: 20595801 DOI: 10.1007/bf03346702] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Hematopoietic stem cell transplantation (HSCT) is used in the treatment of several hematological and non-hematological disorders. An increasing number of long-term survivors recover from their primary disease, but they are at risk of adverse late effects, including metabolic syndrome (MS), which seems to be common in long-term survivors of HSCT. AIM To compare common metabolic parameters and adipohormone profiles in post-transplant and spontaneously occurring or "classic" MS patients. SUBJECTS AND METHODS Post-transplant MS patients (15 women and 14 men; 49.8±9.3 yr) were compared to "classic" MS patients (15 women and 14 men; 52.9±8.0 yr). For each subject a record of conventional clinical parameters was made; moreover, serum leptin, insulin, quantitative C-reactive protein (CRP), tumor necrosis factor-α [TNF-α], and adiponectin concentrations were measured. RESULTS The patients with post-HSCT MS had significantly higher levels of leptin, CRP, and TNF-α than the patients with "classic" MS. A generalized linear model comprising serum insulin (p=0.022), body mass index (p<0.001), gender (p<0.001), and group (i.e. healthy, post-HSCT with MS, or suffering from "classic" MS; p<0.001) explained serum leptin variability (adjusted R(2)=0.741). Serum leptin concentrations and BMI were related in the patients with "classic" MS but not in those with post-HSCT MS. CONCLUSIONS A possible pathogenetic mechanism in the development of MS after HSCT could be hyperleptinemia. A potential interaction among circulating leptin, components of MS, and immune function might explain the role of this adipokine in mediating cardiovascular risk after HSCT.
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Affiliation(s)
- L Airaghi
- First Internal Medicine Unit, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Via F. Sforza 35, 20122 Milano, Italy.
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Abstract
The world is now experiencing an epidemic of obesity. Although the effects of obesity on the development of metabolic and cardiovascular problems are well studied, much less is known about the impact of obesity on immune function and infectious disease. Studies in obese humans and with obese animal models have repeatedly demonstrated impaired immune function, including decreased cytokine production, decreased response to antigen/mitogen stimulation, reduced macrophage and dendritic cell function, and natural killer cell impairment. Recent studies have demonstrated that the impaired immune response in the obese host leads to increased susceptibility to infection with a number of different pathogens such as community-acquired tuberculosis, influenza, Mycobacterium tuberculosis, coxsackievirus, Helicobacter pylori and encephalomyocarditis virus. While no specific mechanism has been defined for the decreased immune response to infectious disease in the obese host, several obesity-associated changes such as excessive inflammation, altered adipokine signaling, metabolic changes and even epigenetic regulation could affect the immune response. This review will discuss what is currently known about the relationship between obesity and infectious disease.
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Affiliation(s)
- Erik A Karlsson
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN 38105-3678
| | - Melinda A Beck
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599-7461, USA
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Luo W, Bodary PF, Shen Y, Wickenheiser KJ, Ohman MK, Guo C, Bahrou KL, Myers MG, Eitzman DT. Leptin receptor-induced STAT3-independent signaling pathways are protective against atherosclerosis in a murine model of obesity and hyperlipidemia. Atherosclerosis 2010; 214:81-5. [PMID: 21067751 DOI: 10.1016/j.atherosclerosis.2010.10.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Revised: 10/07/2010] [Accepted: 10/08/2010] [Indexed: 11/25/2022]
Abstract
AIMS Leptin is an adipocyte-derived hormone that has been shown to exert both beneficial metabolic effects and potentially adverse vascular effects in preclinical studies. The primary aim of this study was to determine the effects of leptin receptor signaling pathways on atherosclerosis in the setting of obesity and hyperlipidemia. METHODS AND RESULTS Mice were generated with deficiency of apolipoprotein E (ApoE(-/-)) and either wild-type leptin receptor expression (Lepr(+/+), ApoE(-/-)), mutant leptin receptor expression defective in all leptin receptor signaling pathways (Lepr(db/db), ApoE(-/-)), or mutant leptin receptor expression with selective deficiency of leptin receptor-STAT3 signaling (Lepr(s/s), ApoE(-/-)). At 27 weeks of age (including 7 weeks on a Western diet), Lepr(db/db), ApoE(-/-) developed severe obesity, hypercholesterolemia, and increased atherosclerosis compared to Lepr(+/+), ApoE(-/-) mice. Despite similar obesity and hyperlipidemia to Lepr(db/db), ApoE(-/-) mice, Lepr(s/s), ApoE(-/-) developed less atherosclerosis than Lepr(db/db), ApoE(-/-) mice. Adipose tissue macrophage content, monocyte chemoattractant protein-1 and fatty-acid-binding protein 4 levels were also reduced in Lepr(s/s), ApoE(-/-) mice compared to Lepr(db/db), ApoE(-/-) mice. CONCLUSIONS In a mouse model of obesity and hyperlipidemia, leptin receptor-mediated STAT3-independent signaling pathways confer protection against atherosclerosis. These differences occur independently of leptin effects on energy balance.
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Affiliation(s)
- Wei Luo
- University of Michigan, Department of Internal Medicine, Ann Arbor, MI, USA
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232
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The HIV-1/HAART associated metabolic syndrome – Novel adipokines, molecular associations and therapeutic implications. J Infect 2010; 61:101-13. [DOI: 10.1016/j.jinf.2010.06.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Revised: 05/18/2010] [Accepted: 06/07/2010] [Indexed: 10/19/2022]
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233
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Behrendt P, Buchenauer T, Horn R, Brabant G, Jacobs R, Bode F, Stephan M, Nave H. Diet-induced obesity, exogenous leptin-, and MADB106 tumor cell challenge affect tissue leukocyte distribution and serum levels of cytokines in F344 rats. Endocrine 2010; 38:104-12. [PMID: 20960110 DOI: 10.1007/s12020-010-9358-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Accepted: 06/02/2010] [Indexed: 11/28/2022]
Abstract
The adipocyte-derived catabolic protein leptin alters cell-mediated immunity and cytokine crosstalk. This may provide new insights into the altered immune response, seen in obese individuals. Therefore, we determined the tissue distribution of immune cells in diet-induced obese (dio) and normal weight F344 rats challenged with MADB106 tumor cells or leptin. Immune cell distribution in blood (by FACS analysis) and tissues (NK cells in spleen and liver, immunohistologically) as well as pro-inflammatory cytokines (IL-6, TNF-α; by flow cytometry) were investigated in 28 normal weight and 28 dio rats (n = 4-6/group). Pro-inflammatory cytokines were increased 3-fold for IL-6 and 7-fold for TNF-α in obese animals. Higher numbers of blood monocytes and NK cells were found in obese as compared to normal weight animals. In dio rats challenged with leptin and MADB106 tumor cells, monocyte numbers were decreased as compared to the obese control animals. Immunohistochemistry revealed an altered NK cell distribution in a compartment-, treatment-, and bodyweight-specific manner. In conclusion, our data reveal a distinct distribution pattern of monocytes and NK cells in dio rats as compared to normal weight littermates and an additional modulatory effect of a leptin- and MADB106 tumor cell challenge.
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Affiliation(s)
- Patrick Behrendt
- Institute for Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
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234
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Kim SJ. Leptin potentiates Prevotella intermedia lipopolysaccharide-induced production of TNF-alpha in monocyte-derived macrophages. J Periodontal Implant Sci 2010; 40:119-24. [PMID: 20607056 PMCID: PMC2895517 DOI: 10.5051/jpis.2010.40.3.119] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Accepted: 05/05/2010] [Indexed: 11/08/2022] Open
Abstract
PURPOSE In addition to regulating body weight, leptin is also recognized for its role in the regulation of immune function and inflammation. The purpose of this study was to investigate the effect of leptin on Prevotella (P.) intermedia lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-alpha production in differentiated THP-1 cells, a human monocytic cell line. METHODS LPS from P. intermedia ATCC 25611 was prepared by the standard hot phenol-water method. THP-1 cells were incubated in the medium supplemented with phorbol myristate acetate to induce differentiation into macrophage-like cells. The amount of TNF-alpha and interleukin-8 secreted into the culture medium was determined by enzyme-linked immunosorbent assay (ELISA). TNF-alpha and Ob-R mRNA expression levels were determined by semi-quantitative reverse transcription-polymerase chain reaction analysis. RESULTS Leptin enhanced P. intermedia LPS-induced TNF-alpha production in a dose-dependent manner. Leptin modulated P. intermedia LPS-induced TNF-alpha expression predominantly at the transcriptional level. Effect of leptin on P. intermedia LPS-induced TNF-alpha production was not mediated by the leptin receptor. CONCLUSIONS The ability of leptin to enhance P. intermedia LPS-induced TNF-alpha production may be important in the establishment of chronic lesion accompanied by osseous tissue destruction observed in inflammatory periodontal disease.
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Affiliation(s)
- Sung-Jo Kim
- Department of Periodontology, Pusan National University College of Dentistry, Yangsan, Korea
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Pérez-Pérez A, Gambino Y, Maymó J, Goberna R, Fabiani F, Varone C, Sánchez-Margalet V. MAPK and PI3K activities are required for leptin stimulation of protein synthesis in human trophoblastic cells. Biochem Biophys Res Commun 2010; 396:956-60. [DOI: 10.1016/j.bbrc.2010.05.031] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 05/06/2010] [Indexed: 11/28/2022]
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Matarese G, Procaccini C, De Rosa V, Horvath TL, La Cava A. Regulatory T cells in obesity: the leptin connection. Trends Mol Med 2010; 16:247-56. [PMID: 20493774 DOI: 10.1016/j.molmed.2010.04.002] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2010] [Revised: 04/06/2010] [Accepted: 04/08/2010] [Indexed: 01/15/2023]
Abstract
Studies to understand the pathogenesis of obesity have revealed mediators that are responsible for the control of food intake and metabolism at the hypothalamic level. However, molecular insight explaining the link between obesity and low-degree chronic inflammation remains elusive. The adipocyte-derived hormone leptin, and thereby the nutritional status, could control immune self-tolerance by affecting regulatory T (Treg) cell responsiveness and function. Furthermore, resident Treg cells, which are capable of modulating metabolism and glucose homeostasis, are abundant in adipose tissue. Here, we provide an update on recent findings relating Treg cells to obesity and discuss how the intricate network of interactions among leptin, Treg cells and adipose tissue might provide new strategies for therapeutic interventions.
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Affiliation(s)
- Giuseppe Matarese
- Laboratorio di Immunologia, Istituto di Endocrinologia e Oncologia Sperimentale, Consiglio Nazionale delle Ricerche (IEOS-CNR), Napoli, Italy.
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237
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Vernooy JHJ, Bracke KR, Drummen NEA, Pauwels NSA, Zabeau L, van Suylen RJ, Tavernier J, Joos GF, Wouters EFM, Brusselle GG. Leptin modulates innate and adaptive immune cell recruitment after cigarette smoke exposure in mice. THE JOURNAL OF IMMUNOLOGY 2010; 184:7169-77. [PMID: 20488786 DOI: 10.4049/jimmunol.0900963] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Leptin, a pleiotropic type I cytokine, was recently demonstrated to be expressed by resident lung cells in chronic obstructive pulmonary disease patients and asymptomatic smokers. To elucidate the functional role of leptin in the onset of chronic obstructive pulmonary disease, we tested leptin-deficient ob/ob mice (C57BL/6), leptin receptor-deficient db/db mice (C57BKS), and littermates in a model of cigarette smoke (CS)-induced pulmonary inflammation. Wild-type (WT) C57BL/6 mice were exposed for 4 or 24 wk to control air or CS. Pulmonary leptin expression was analyzed by immunohistochemistry and real-time PCR. Pulmonary inflammation upon 4 wk CS exposure was evaluated in bronchoalveolar lavage fluid (BALF) and lung tissue of WT, ob/ob, and db/db mice. Immunohistochemical analysis revealed leptin expression in bronchial epithelial cells, pneumocytes, alveolar macrophages, and bronchial/vascular smooth muscle cells. The 4 and 24 wk CS exposure increased leptin expression in bronchial epithelial cells and pneumocytes versus air-exposed WT mice (p<0.05). The 4 wk CS exposure resulted in increased accumulation of neutrophils, dendritic cells, macrophages, and lymphocytes in BALF and lung tissue of WT, ob/ob, and db/db mice. CS-exposed ob/ob and db/db mice showed in general higher numbers of neutrophils and lower numbers of CD4+, CD8+, and dendritic cells versus CS-exposed WT mice. Consistently, CXCL1 levels were enhanced in BALF of CS-exposed ob/ob and db/db mice versus WT mice (p<0.05). Exogenous leptin administration completely restored the skewed inflammatory profile in ob/ob mice. These data reveal an important role of leptin in modulating innate and adaptive immunity after CS inhalation in mice.
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Affiliation(s)
- Juanita H J Vernooy
- Department of Respiratory Medicine, NUTRIM School for Nutrition, Toxicology and Metabolism, Horn, The Netherlands.
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238
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Demas GE. In vivo but not in vitro leptin enhances lymphocyte proliferation in Siberian hamsters (Phodopus sungorus). Gen Comp Endocrinol 2010; 166:314-9. [PMID: 19896948 DOI: 10.1016/j.ygcen.2009.10.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 10/06/2009] [Accepted: 10/28/2009] [Indexed: 11/16/2022]
Abstract
Mounting an immune response requires a relatively substantial investment of energy and marked reductions in energy availability can suppress immune function and presumably increase disease susceptibility. We have previously demonstrated that a moderate reduction in energy stores by partial surgical lipectomy impairs humoral immunity of Siberian hamsters (Phodopus sungorus) and is mediated, in part, by changes in the adipose tissue hormone leptin. The goals of the present study were to assess the role of leptin in cell-mediated immunity and to determine if the potential effects of leptin on immunity are via the direct actions of this hormone on lymphocytes, or indirect, via the sympathetic nervous system (SNS). In Experiment 1, hamsters received osmotic minipumps containing either murine leptin (0.5 microl/h) or vehicle alone for 10 days and splenocyte proliferation in response to the T-cell mitogen Concanavalin A (Con A) was determined. In Experiment 2, Con A-induced splenocyte proliferation was tested in the presence or absence of leptin in vitro. In Experiment 3, exogenous leptin was administered to intact or sympathetically denervated hamsters. Hamsters treated with in vivo leptin displayed increased splenocyte proliferation compared with control hamsters receiving vehicle. In contrast, in vitro leptin had no effect on splenocyte proliferation. Sympathetic denervation attenuated, but did not block, leptin-induced increases in immunity. Taken together, these results are consistent with the idea that leptin can enhance cell-mediated immunity; the SNS appears to contribute, least in part, to leptin-induced increases in immunity. Importantly, these findings confirm previous studies that leptin serves as an important endocrine link between energy balance and immunity.
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Affiliation(s)
- Gregory E Demas
- Department of Biology, Program in Neuroscience and the Center for the Integrative Study of Animal Behavior, Indiana University, 1001 E. 3rd Street, Bloomington, IN 47405, USA.
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Role of leptin in the activation of immune cells. Mediators Inflamm 2010; 2010:568343. [PMID: 20368778 PMCID: PMC2846344 DOI: 10.1155/2010/568343] [Citation(s) in RCA: 274] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 01/15/2010] [Accepted: 01/23/2010] [Indexed: 01/29/2023] Open
Abstract
Adipose tissue is an active endocrine organ that secretes various humoral factors (adipokines), and its shift to production of proinflammatory cytokines in obesity likely contributes to the low-level systemic inflammation that may be present in metabolic syndrome-associated chronic pathologies such as atherosclerosis. Leptin is one of the most important hormones secreted by adipocytes, with a variety of physiological roles related to the control of metabolism and energy homeostasis. One of these functions is the connection between nutritional status and immune competence. The adipocyte-derived hormone leptin has been shown to regulate the immune response, innate and adaptive response, both in normal and pathological conditions. The role of leptin in regulating immune response has been assessed in vitro as well as in clinical studies. It has been shown that conditions of reduced leptin production are associated with increased infection susceptibility. Conversely, immune-mediated disorders such as autoimmune diseases are associated with increased secretion of leptin and production of proinflammatory pathogenic cytokines. Thus, leptin is a mediator of the inflammatory response.
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Abstract
Epidemiological data indicate that obesity is a risk factor for asthma, but the mechanistic basis for this relationship is not established. Here we review data from human subjects and animal models investigating the relationship between obesity and airway hyperresponsiveness, a characteristic feature of asthma. We discuss obesity as a state of chronic systemic inflammation resulting from interactions between adipocytes and adipose tissue macrophages that are recruited to obese adipose tissue. Finally, we focus on the possibility that aspects of this inflammation, particularly obesity-related changes in TNF-alpha, leptin, and adiponectin, may contribute to airway hyperresponsiveness in obesity. Determining how obesity promotes asthma may uncover novel therapeutic strategies that are effective in the obese asthmatic subject.
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Affiliation(s)
- Stephanie A Shore
- Department of Environmental Health, Harvard School of Public Health, 665 Huntington Ave., Boston, MA 02115, USA.
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242
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Abstract
Epidemiological data indicate that obesity is a risk factor for asthma, but the mechanistic basis for this relationship is not established. Here we review data from human subjects and animal models investigating the relationship between obesity and airway hyperresponsiveness, a characteristic feature of asthma. We discuss obesity as a state of chronic systemic inflammation resulting from interactions between adipocytes and adipose tissue macrophages that are recruited to obese adipose tissue. Finally, we focus on the possibility that aspects of this inflammation, particularly obesity-related changes in TNF-alpha, leptin, and adiponectin, may contribute to airway hyperresponsiveness in obesity. Determining how obesity promotes asthma may uncover novel therapeutic strategies that are effective in the obese asthmatic subject.
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Affiliation(s)
- Stephanie A Shore
- Program in Molecular and Integrative Physiological Sciences, Harvard School of Public Health, 665 Huntington Ave., Boston, MA 02115, USA.
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243
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Yan J, Tie G, Park B, Yan Y, Nowicki PT, Messina LM. Recovery from hind limb ischemia is less effective in type 2 than in type 1 diabetic mice: roles of endothelial nitric oxide synthase and endothelial progenitor cells. J Vasc Surg 2009; 50:1412-22. [PMID: 19837544 DOI: 10.1016/j.jvs.2009.08.007] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 08/03/2009] [Accepted: 08/03/2009] [Indexed: 01/23/2023]
Abstract
OBJECTIVE We sought to directly compare the effects of type 1 and type 2 diabetes on postischemic neovascularization and evaluate the mechanisms underlying differences between these groups. We tested the hypothesis that type 2 diabetic mice have a greater reduction in endothelial nitric oxide synthase (eNOS) expression, a greater increase in oxidative stress, and reduced arteriogenesis and angiogenesis, resulting in less complete blood flow recovery than type 1 diabetic mice after induction of hind limb ischemia. METHODS Hind limb ischemia was generated by femoral artery excision in streptozotocin-treated mice (model of type 1 diabetes), in Lepr(db/db) mice (model of type 2 diabetes), and in control (C57BL/6) mice. Dependent variables included eNOS expression and markers of arteriogenesis, angiogenesis, and oxidative stress. RESULTS Postischemia recovery of hind limb perfusion was significantly less in type 2 than in type 1 diabetic mice; however, neither group demonstrated a significant increase in collateral artery diameter or collateral artery angioscore in the ischemic hind limb. The capillary/myofiber ratio in the gastrocnemius muscle decreased in response to ischemia in control or type 1 diabetic mice but remained the same in type 2 diabetic mice. Gastrocnemius muscle eNOS expression was lower in type 1 and 2 diabetic mice than in control mice. This expression decreased after induction of ischemia in type 2 but not in type 1 diabetic mice. The percentage of endothelial progenitor cells (EPC) in the peripheral blood failed to increase in either diabetic group after induction of ischemia, whereas this variable significantly increased in the control group in response to ischemia. EPC eNOS expression decreased after induction of ischemia in type 1 but not in type 2 diabetic mice. EPC nitrotyrosine accumulation increased after induction of ischemia in type 2 but not in type 1 diabetic mice. EPC migration in response to vascular endothelial growth factor was reduced in type 1 and type 2 diabetic mice vs control mice. EPC incorporation into tubular structures was less effective in type 2 diabetic mice. Extensive fatty infiltration was present in ischemic muscle of type 2 but not in type 1 diabetic mice. CONCLUSION Type 2 diabetic mice displayed a significantly less effective response to hind limb ischemia than type 1 diabetic mice.
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Affiliation(s)
- Jinglian Yan
- Department of Surgery, University of Massachusetts Medical School, Worcester, Mass 01655, USA
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244
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Dixon D, Meng H, Goldberg R, Schneiderman N, Delamater A. Stress and body mass index each contributes independently to tumor necrosis factor-alpha production in prepubescent Latino children. J Pediatr Nurs 2009; 24:378-88. [PMID: 19782896 PMCID: PMC2776709 DOI: 10.1016/j.pedn.2008.02.034] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Revised: 02/26/2008] [Accepted: 02/26/2008] [Indexed: 10/21/2022]
Abstract
This investigation extended prior work by determining if stress and body mass index (BMI) contributed independently to tumor necrosis factor-alpha (TNF-alpha) levels among prepubescent Latino children and if sex and family history of type 2 diabetes mellitus (T2DM) modified these relationships. Data were collected in South Florida from 112 nondiabetic school-aged Hispanic children, of whom 43.8% were obese (BMI >/= 95th percentile) and 51.8% presented with a family history of T2DM. Stressful life events were assessed via parental report using a life events scale. Plasma TNF-alpha levels were determined with enzyme-linked immunosorbent assay. The relative contributions of stress and BMI with TNF-alpha levels and the potential interaction effects of sex and family history of T2DM were analyzed with multiple linear regression analyses. Stress and BMI each accounted for a significant proportion of the unique variance associated with TNF-alpha. The association between stress and TNF-alpha was not modified by sex or family history of T2DM. These findings implicate BMI and stress as independent determinants of TNF-alpha (an inflammatory cytokine and adipocytokine) among Latino children. Future investigations should examine the potential roles of exercise, nutritional status, age, and growth hormone in explicating the relationship between TNF-alpha production and psychosocial distress and risk for infection among obese children.
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Affiliation(s)
- Denise Dixon
- University of Miami Behavioral Medicine Research Center, c/o VA Medical Center, Miami, FL, USA.
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245
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Petta S, Muratore C, Craxì A. Non-alcoholic fatty liver disease pathogenesis: the present and the future. Dig Liver Dis 2009; 41:615-25. [PMID: 19223251 DOI: 10.1016/j.dld.2009.01.004] [Citation(s) in RCA: 192] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Revised: 12/31/2008] [Accepted: 01/08/2009] [Indexed: 02/07/2023]
Abstract
Non-alcoholic fatty liver disease is the clinical hepatic expression of metabolic syndrome. The prevalence of non-alcoholic fatty liver disease is around 20-30%, and with a rapid increase in the metabolic risk factors in the general population, non-alcoholic fatty liver disease has become the most common cause of liver disease worldwide. A fraction (20-30%) of non-alcoholic fatty liver disease patients develop a potentially progressive hepatic disorder, namely non-alcoholic steatohepatitis, leading to end-stage liver disease. The pathogenesis of non-alcoholic fatty liver disease is not entirely understood, and even if insulin resistance is a major pathogenetic key, many other factors are implicated in both liver fat accumulation and disease progression to non-alcoholic steatohepatitis. In this review we aim to examine the literature, principally concerning human non-alcoholic fatty liver disease pathogenesis, and to identify the newest, most promising clinical and basic research data.
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Affiliation(s)
- S Petta
- Cattedra & Unità Operativa di Gastroenterologia, Di.Bi.M.I.S., University of Palermo, Palermo, Italy.
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246
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The influence of leptin on the activity of lung lymphocytes under simulated microgravity. Eur J Appl Physiol 2009; 107:335-44. [PMID: 19626337 DOI: 10.1007/s00421-009-1129-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2009] [Indexed: 10/20/2022]
Abstract
Exposure to microgravity has been implicated in the compromised immune function in space travellers, resulting in opportunistic infections, poor wound healing, and cancer. Since recent studies have suggested that leptin was capable of modulating immune responses, the purpose of this study was to examine effects of microgravity on the activation and proliferation of rat lung lymphocytes and then to examine the effects of leptin-mediated signal transduction mechanisms of lymphocyte activation in these same conditions. In control conditions (T-flasks cultured cells) leptin was not able by itself to increase lymphocytes proliferation, or induce significant increase of either IL-2 production or expression of lymphocytes activation markers, such as CD25 and CD71, while it markedly enhanced the positive effects induced on these parameters by concanavalin A (ConA). Using clinostatic rotating wall vessel (RWV) bioreactors to simulate a microgravity environment, we found that ConA responsiveness was inhibited. Moreover, under these conditions, leptin was not able to reverse these impaired functions. Accordingly with the above cited inhibitory effects exerted by the simulated microgravity environment, evidence was also obtained of defects in lymphocyte intracellular signal transduction induced by the incubation in RWV bioreactors, namely concerning decreased ConA-mediated PKC activity, and reduced expression of NF-kappaB, c-fos, and ERK1/2. Again, leptin appeared to be unable in restoring a physiologic increase of these parameters, different from what could be observed after complementation of the ConA-mediated signalling with phorbol myristate acetate, which instead demonstrated to overcome the inhibition of lymphocytes activating functions, in the presence of simulated microgravity conditions.
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247
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Durazzo M, Niro G, Premoli A, Morello E, Rizzotto ER, Gambino R, Bo S, Musso G, Cassader M, Pagano G, Floreani A. Type 1 autoimmune hepatitis and adipokines: new markers for activity and disease progression? J Gastroenterol 2009; 44:476-82. [PMID: 19301087 DOI: 10.1007/s00535-009-0023-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2008] [Accepted: 12/10/2008] [Indexed: 02/04/2023]
Abstract
PURPOSE Cytokines may play an important role as inflammatory factors in liver diseases. There is some evidence suggesting a link between adiponectin-biliary function and liver disease. The aim of this study was to clarify the behavior of adipokines in autoimmune hepatitis type 1. METHODS We assessed the circulating levels of adiponectin, tumor necrosis factor-alpha, resistin and leptin in 42 patients with autoimmune hepatitis, comparing them with 42 healthy subjects who were matched for age and sex and with 31 patients with nonalcoholic steatohepatitis (NASH), evaluating the associations with markers of cytolysis, cholestasis, and histological severity. RESULTS Adiponectin and TNF-alpha values were higher in patients compared to controls. The patients showed significantly higher Homeostasis Model Assessment values, suggesting an increased insulin resistance and serum levels of adiponectin positively correlated with gamma-glutamyltranspeptidase and alkaline phosphatase values after a simple regression analysis. Serum levels of resistin positively correlated with elevated aminotransferases and bilirubin values, and serum levels of TNF-alpha positively correlated with elevated alanine-aminotransferase and resistin values. The concentration of adiponectin increased significantly with staging of the disease. Patients with NASH showed lower levels of adiponectin and higher levels of resistin than AIH patients and controls. CONCLUSIONS Patients with AIH showed significantly higher adiponectin concentrations than controls despite their higher HOMA-IR values. The significant correlation between adiponectin levels and serological features of cholestasis suggested an association with biliary function. Our results indicate that adiponectin may be a possible marker for disease progression in AIH.
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Affiliation(s)
- Marilena Durazzo
- Department of Internal Medicine, University of Turin, Turin, Italy.
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Pérez-Pérez A, Maymó J, Gambino Y, Dueñas JL, Goberna R, Varone C, Sánchez-Margalet V. Leptin stimulates protein synthesis-activating translation machinery in human trophoblastic cells. Biol Reprod 2009; 81:826-32. [PMID: 19553602 DOI: 10.1095/biolreprod.109.076513] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Leptin was originally considered as an adipocyte-derived signaling molecule for the central control of metabolism. However, pleiotropic effects of leptin have been identified in reproduction and pregnancy, particularly in placenta, where it may work as an autocrine hormone, mediating angiogenesis, growth, and immunomodulation. Leptin receptor (LEPR, also known as Ob-R) shows sequence homology to members of the class I cytokine receptor (gp130) superfamily. In fact, leptin may function as a proinflammatory cytokine. We have previously found that leptin is a trophic and mitogenic factor for trophoblastic cells. In order to further investigate the mechanism by which leptin stimulates cell growth in JEG-3 cells and trophoblastic cells, we studied the phosphorylation state of different proteins of the initiation stage of translation and the total protein synthesis by [(3)H]leucine incorporation in JEG-3 cells. We have found that leptin dose-dependently stimulates the phosphorylation and activation of the translation initiation factor EIF4E as well as the phosphorylation of the EIF4E binding protein EIF4EBP1 (PHAS-I), which releases EIF4E to form active complexes. Moreover, leptin dose-dependently stimulates protein synthesis, and this effect can be partially prevented by blocking mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3 kinase (PIK3) pathways. In conclusion, leptin stimulates protein synthesis, at least in part activating the translation machinery, via the activation of MAPK and PIK3 pathways.
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Affiliation(s)
- Antonio Pérez-Pérez
- Departamento de Bioquímica Médica y Biología Molecular, Hospital Universitario Virgen Macarena, Universidad de Sevilla, Seville, Spain
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Procaccini C, Lourenco EV, Matarese G, La Cava A. Leptin signaling: A key pathway in immune responses. ACTA ACUST UNITED AC 2009; 4:22-30. [PMID: 19774101 DOI: 10.2174/157436209787048711] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Leptin is a hormone whose central role is to regulate endocrine functions and to control energy expenditure. After the discovery that leptin can also have pro-inflammatory effects, several studies have tried to address - at the molecular level - the pathways involved in leptin-induced modulation of the immune functions in normal and pathologic conditions. The signaling events influenced by leptin after its binding to the leptin receptor have been under scrutiny in the past few years, and considerable experimental work has elucidated the consequences of leptin effects on immune cells. This review examines the biochemistry, function and regulation of leptin signaling in view of possible intervention on this molecule for a better management and therapy of immune-mediated diseases.
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Affiliation(s)
- Claudio Procaccini
- Department of Medicine, University of California Los Angeles, Los Angeles, California 90095
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IL-1 family in breast cancer: potential interplay with leptin and other adipocytokines. FEBS Lett 2008; 583:259-65. [PMID: 19111549 DOI: 10.1016/j.febslet.2008.12.030] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Revised: 11/17/2008] [Accepted: 12/11/2008] [Indexed: 12/15/2022]
Abstract
Obesity is associated with an increased risk of breast cancer. interleukin-1 (IL-1), a pro-inflammatory cytokine secreted by adipose tissue, is involved in breast cancer development. There is also convincing evidence that other adipocytokines including leptin not only have a role in haematopoiesis, reproduction and immunity but are also growth factors in cancer. Therefore, IL-1 family and leptin family are adipocytokines which could represent a major link between obesity and breast cancer progression. This minireview provides insight into recent findings on the prognostic significance of IL-1 and leptin in mammary tumours, and discusses the potential interplay between IL-1 family members and adipocyte-derived hormones in breast cancer.
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