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Knights AJ, Funnell APW, Pearson RCM, Crossley M, Bell-Anderson KS. Adipokines and insulin action: A sensitive issue. Adipocyte 2014; 3:88-96. [PMID: 24719781 PMCID: PMC3979885 DOI: 10.4161/adip.27552] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 12/11/2013] [Accepted: 12/16/2013] [Indexed: 02/06/2023] Open
Abstract
Obesity is a major public health concern and a strong risk factor for insulin resistance, type 2 diabetes mellitus (T2DM), and cardiovascular disease. The last two decades have seen a reconsideration of the role of white adipose tissue (WAT) in whole body metabolism and insulin action. Adipose tissue-derived cytokines and hormones, or adipokines, are likely mediators of metabolic function and dysfunction. While several adipokines have been associated with obese and insulin-resistant phenotypes, a select group has been linked with insulin sensitivity, namely leptin, adiponectin, and more recently, adipolin. What is known about these insulin-sensitizing molecules and their effects in healthy and insulin resistant states is the subject of this review. There remains a significant amount of research to do to fully elucidate the mechanisms of action of these adipokines for development of therapeutics in metabolic disease.
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Affiliation(s)
- Alexander J Knights
- School of Biotechnology and Biomolecular Sciences; University of New South Wales; Sydney, NSW Australia
| | - Alister PW Funnell
- School of Biotechnology and Biomolecular Sciences; University of New South Wales; Sydney, NSW Australia
| | - Richard CM Pearson
- School of Biotechnology and Biomolecular Sciences; University of New South Wales; Sydney, NSW Australia
| | - Merlin Crossley
- School of Biotechnology and Biomolecular Sciences; University of New South Wales; Sydney, NSW Australia
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202
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Wu FJ, Xu Y, Bao J, Liu X. Non-alcoholic fatty liver disease complicated with autoimmune problems: Analysis of 132 cases. Shijie Huaren Xiaohua Zazhi 2014; 22:1294-1299. [DOI: 10.11569/wcjd.v22.i9.1294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To analyze the relationship between non-alcoholic fatty liver disease (NAFLD) and autoimmune diseases.
METHODS: One hundred and thirty-two patients with biopsy-proven NAFLD were divided into four groups: 1 [patients with NAFLD and autoimmune liver disease (AILD)], 2 (patients with NAFLD and autoimmune disease except AILD), 3 (patients with NAFLD and autoimmune phenomena) and 4 (patients with NAFLD alone). All data on clinical and biochemistry indexes, autoantibodies, imaging findings and liver histology were analyzed.
RESULTS: The difference in AST was statistically significant between groups 1 and 4 (P < 0.05). There were significant differences in IgG in groups 1, 2 and 3 compared with group 4 (P < 0.05 for all). Liver stiffness, fibrosis stage and inflammation level were different significantly between group 1 and groups 2, 3 and 4 (P < 0.05 for all).
CONCLUSION: The levels of IgG, liver stiffness, liver fibrosis and hepatic inflammation were correlated with the severity of autoimmune problems. IgG and liver stiffness may act as long-term follow-up indicators.
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203
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Rivera-Gonzalez G, Shook B, Horsley V. Adipocytes in skin health and disease. Cold Spring Harb Perspect Med 2014; 4:4/3/a015271. [PMID: 24591537 DOI: 10.1101/cshperspect.a015271] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Adipocytes are intimately associated with the dermal compartment of the skin, existing in a specialized dermal depot and displaying dynamic changes in size during tissue homeostasis. However, the roles of adipocytes in cutaneous biology and disease are not well understood. Traditionally, adipocytes within tissues were thought to act as reservoirs of energy, as thermal, or as structural support. In this review, we discuss recent studies revealing the cellular basis of the dynamic development and regenerative capacity of dermal adipocytes associated with the hair cycle and following injury. We discuss and speculate on potential roles of dermal adipocytes in cutaneous biology with an emphasis on communication during hair follicle growth and wound healing. Finally, we explore how alterations in the dermal adipose tissue may support clinical manifestations of cutaneous diseases such as lipodystrophy, obesity, and alopecia.
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Affiliation(s)
- Guillermo Rivera-Gonzalez
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520
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204
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Leptin and leptin-related gene polymorphisms, obesity, and influenza A/H1N1 vaccine-induced immune responses in older individuals. Vaccine 2013; 32:881-7. [PMID: 24360890 DOI: 10.1016/j.vaccine.2013.12.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 11/15/2013] [Accepted: 12/01/2013] [Indexed: 02/08/2023]
Abstract
Obesity is a risk factor for complicated influenza A/H1N1 disease and poor vaccine immunogenicity. Leptin, an adipocyte-derived hormone/cytokine, has many immune regulatory functions and therefore could explain susceptibility to infections and poor vaccine outcomes. We recruited 159 healthy adults (50-74 years old) who were immunized with inactivated TIV influenza vaccine that contained A/California/7/2009/H1N1 virus. We found a strong correlation between leptin concentration and BMI (r=0.55, p<0.0001), but no association with hemagglutination antibody inhibition (HAI), B-cell, or granzyme B responses. We found a slight correlation between leptin concentration and an immunosenescence marker (TREC: T-cell receptor excision circles) level (r=0.23, p=0.01). We found eight SNPs in the LEP/LEPR/GHRL genes that were associated with leptin levels and four SNPs in the PTPN1/LEPR/STAT3 genes associated with peripheral blood TREC levels (p<0.05). Heterozygosity of the synonymous variant rs2230604 in the PTPN1 gene was associated with a significantly lower (531 vs. 259, p=0.005) TREC level, as compared to the homozygous major variant. We also found eight SNPs in the LEP/PPARG/CRP genes associated with variations in influenza-specific HAI and B-cell responses (p<0.05). Our results suggest that specific allelic variations in the leptin-related genes may influence adaptive immune responses to influenza vaccine.
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205
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Singh UP, Singh NP, Guan H, Busbee B, Price RL, Taub DD, Mishra MK, Fayad R, Nagarkatti M, Nagarkatti PS. Leptin antagonist ameliorates chronic colitis in IL-10⁻/⁻ mice. Immunobiology 2013; 218:1439-51. [PMID: 23726523 PMCID: PMC3778116 DOI: 10.1016/j.imbio.2013.04.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 04/27/2013] [Accepted: 04/27/2013] [Indexed: 02/07/2023]
Abstract
BACKGROUND Although the etiology of two major forms of inflammatory bowel disease (IBD), Crohn's disease (CD) and ulcerative colitis (UC) are unknown and evidence suggests that chronic intestinal inflammation is caused by an excessive immune response to mucosal antigens. Previous studies support the role for TGF-β1 through 3 in the initiation and maintenance of tolerance via the induction of regulatory T cells (Tregs) to control intestinal inflammation. Leptin, a satiety hormone produced primarily by adipose tissue, has been shown to increase during colitis progression and is believed to contribute to disease genesis and/or progression. AIM We investigated the ability of a pegylated leptin antagonist (PG-MLA) to ameliorate the development of chronic experimental colitis. RESULTS Compared to vehicle control animals, PG-MLA treatment of mice resulted in an (1) attenuated clinical score; (2) reversed colitis-associated pathogenesis including a decrease in body weight; (3) reduced systemic and mucosal inflammatory cytokine expression; (4) increased insulin levels and (5) enhanced systemic and mucosal Tregs and CD39⁺ Tregs in mice with chronic colitis. The percentage of systemic and mucosal TGF-β1, -β2 and -β3 expressing CD4⁺ T cells were augmented after PG-MLA treatment. The activation of STAT1 and STAT3 and the expression of Smad7 were also reduced after PG-MLA treatment in the colitic mice. These findings clearly suggest that PG-MLA treatment reduces intestinal Smad7 expression, restores TGF-β1-3 signaling and reduces STAT1/STAT3 activation that may increase the number of Tregs to ameliorate chronic colitis. CONCLUSION This study clearly links inflammation with the metabolic hormone leptin suggesting that nutritional status influences immune tolerance through the induction of functional Tregs. Inhibiting leptin activity through PG-MLA might provide a new and novel therapeutic strategy for the treatment of IBD.
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Affiliation(s)
- Udai P Singh
- Pathology, Microbiology and Immunology, School of Medicine, University of South Carolina, Columbia, SC 29208, USA.
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206
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Martín-González J, Pérez-Pérez A, Sánchez-Jiménez F, Carmona-Fernández A, Torres-Lagares D, Sánchez-Margalet V, Segura-Egea JJ. Leptin Receptor Is Up-regulated in Inflamed Human Dental Pulp. J Endod 2013; 39:1567-71. [DOI: 10.1016/j.joen.2013.08.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 08/07/2013] [Accepted: 08/12/2013] [Indexed: 12/17/2022]
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Saucillo DC, Gerriets VA, Sheng J, Rathmell JC, Maciver NJ. Leptin metabolically licenses T cells for activation to link nutrition and immunity. THE JOURNAL OF IMMUNOLOGY 2013; 192:136-44. [PMID: 24273001 DOI: 10.4049/jimmunol.1301158] [Citation(s) in RCA: 194] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Immune responses are highly energy-dependent processes. Activated T cells increase glucose uptake and aerobic glycolysis to survive and function. Malnutrition and starvation limit nutrients and are associated with immune deficiency and increased susceptibility to infection. Although it is clear that immunity is suppressed in times of nutrient stress, mechanisms that link systemic nutrition to T cell function are poorly understood. We show in this study that fasting leads to persistent defects in T cell activation and metabolism, as T cells from fasted animals had low glucose uptake and decreased ability to produce inflammatory cytokines, even when stimulated in nutrient-rich media. To explore the mechanism of this long-lasting T cell metabolic defect, we examined leptin, an adipokine reduced in fasting that regulates systemic metabolism and promotes effector T cell function. We show that leptin is essential for activated T cells to upregulate glucose uptake and metabolism. This effect was cell intrinsic and specific to activated effector T cells, as naive T cells and regulatory T cells did not require leptin for metabolic regulation. Importantly, either leptin addition to cultured T cells from fasted animals or leptin injections to fasting animals was sufficient to rescue both T cell metabolic and functional defects. Leptin-mediated metabolic regulation was critical, as transgenic expression of the glucose transporter Glut1 rescued cytokine production of T cells from fasted mice. Together, these data demonstrate that induction of T cell metabolism upon activation is dependent on systemic nutritional status, and leptin links adipocytes to metabolically license activated T cells in states of nutritional sufficiency.
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Affiliation(s)
- Donte C Saucillo
- Division of Pediatric Endocrinology and Diabetes, Duke University Medical Center, Durham, NC 27710
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208
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Zhou W, Wang G, Guo S. Regulation of angiogenesis via Notch signaling in breast cancer and cancer stem cells. Biochim Biophys Acta Rev Cancer 2013; 1836:304-20. [PMID: 24183943 DOI: 10.1016/j.bbcan.2013.10.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 10/14/2013] [Accepted: 10/18/2013] [Indexed: 02/07/2023]
Abstract
Breast cancer angiogenesis is elicited and regulated by a number of factors including the Notch signaling. Notch receptors and ligands are expressed in breast cancer cells as well as in the stromal compartment and have been implicated in carcinogenesis. Signals exchanged between neighboring cells through the Notch pathway can amplify and consolidate molecular differences, which eventually dictate cell fates. Notch signaling and its crosstalk with many signaling pathways play an important role in breast cancer cell growth, migration, invasion, metastasis and angiogenesis, as well as cancer stem cell (CSC) self-renewal. Therefore, significant attention has been paid in recent years toward the development of clinically useful antagonists of Notch signaling. Better understanding of the structure, function and regulation of Notch intracellular signaling pathways, as well as its complex crosstalk with other oncogenic signals in breast cancer cells will be essential to ensure rational design and application of new combinatory therapeutic strategies. Novel opportunities have emerged from the discovery of Notch crosstalk with inflammatory and angiogenic cytokines and their links to CSCs. Combinatory treatments with drugs designed to prevent Notch oncogenic signal crosstalk may be advantageous over λ secretase inhibitors (GSIs) alone. In this review, we focus on the more recent advancements in our knowledge of aberrant Notch signaling contributing to breast cancer angiogenesis, as well as its crosstalk with other factors contributing to angiogenesis and CSCs.
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Affiliation(s)
- Weiqiang Zhou
- Key Laboratory of Environmental Pollution and Microecology of Liaoning Province, Shenyang Medical College, No. 146 North Huanghe St, Huanggu Dis, Shenyang City, Liaoning Pro 110034, PR China.
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209
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Zhao J, Lawless MW. Stop feeding cancer: pro-inflammatory role of visceral adiposity in liver cancer. Cytokine 2013; 64:626-37. [PMID: 24120848 DOI: 10.1016/j.cyto.2013.09.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 08/12/2013] [Accepted: 09/06/2013] [Indexed: 02/06/2023]
Abstract
Liver cancer is the fifth most common cancer in the world with an estimated over half a million new cases diagnosed every year. Due to the difficulty in early diagnosis and lack of treatment options, the prevalence of liver cancer continues to climb with a 5-year survival rate of between 6% and 11%. Coinciding with the rise of liver cancer, the prevalence of obesity has rapidly increased over the past two decades. Evidence from epidemiological studies demonstrates a higher risk of hepatocellular carcinoma (HCC) in obese individuals. Obesity is recognised as a low-grade inflammatory disease, this is of particular relevance as inflammation has been proposed as the seventh hallmark of cancer development with abdominal visceral adiposity considered as an important source of pro-inflammatory stimuli. Emerging evidence points towards the direct role of visceral adipose tissue rather than generalised body fat in carcinogenesis. Cytokines such as IL-6 and TNF-α secreted from visceral adipose tissue have been demonstrated to induce a chronic inflammatory condition predisposing the liver to a protumourigenic milieu. This review focuses on excess visceral adiposity rather than simple obesity; particularly adipokines and their implications for chronic inflammation, lipid accumulation, insulin resistance, Endoplasmic Reticulum (ER) stress and angiogenesis. Evidence of molecular signalling pathways that may give rise to the onset and progression of HCC in this context are depicted. Delineation of the pro-inflammatory role of visceral adiposity in liver cancer and its targeting will provide better rational and therapeutic approaches for HCC prevention and elimination. The concept of a central role for metabolism in cancer is the culmination of an effort that began with one of the 20th century's leading biochemists and Nobel laureate of 1931, Otto Warburg.
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Affiliation(s)
- Jun Zhao
- Experimental Medicine, UCD School of Medicine and Medical Science, Mater Misericordiae University Hospital, Dublin 7, Ireland
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210
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Cheung WW, Ding W, Gunta SS, Gu Y, Tabakman R, Klapper LN, Gertler A, Mak RH. A pegylated leptin antagonist ameliorates CKD-associated cachexia in mice. J Am Soc Nephrol 2013; 25:119-28. [PMID: 24115476 DOI: 10.1681/asn.2013040432] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Elevated serum leptin levels correlate with inflammation and predict changes in lean body mass in patients with CKD, and activation of the melanocortin system by leptin signaling mediates the pathophysiology of CKD-associated cachexia. We tested whether treatment with a pegylated leptin receptor antagonist (PLA) attenuates cachexia in mice with CKD. CKD and Sham mice received vehicle or PLA (2 or 7 mg/kg per day). At these doses, PLA did not influence serum leptin levels in mice. Treatment with 7 mg/kg per day PLA stimulated appetite and weight gain, improved lean mass and muscle function, reduced energy expenditure, and normalized the levels of hepatic TNF-α and IL-6 mRNA in mice with CKD. Furthermore, treatment with 7 mg/kg per day PLA attenuated the CKD-associated increase in the transcriptional and protein abundance of uncoupling proteins that mediates thermogenesis, and it normalized the molecular signatures of processes associated with muscle wasting in CKD, including proteolysis, myogenesis and muscle regeneration, and expression of proinflammatory muscle cytokines, such as IL-1α, -1β, and -6 and TNF-α. Our results suggest that leptin antagonism may represent a viable therapeutic strategy for cachexia in CKD.
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Affiliation(s)
- Wai W Cheung
- Division of Pediatric Nephrology, University of California, San Diego, La Jolla, California
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211
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Huebner L, Engeli S, Wrann CD, Goudeva L, Laue T, Kielstein H. Human NK cell subset functions are differentially affected by adipokines. PLoS One 2013; 8:e75703. [PMID: 24098717 PMCID: PMC3787100 DOI: 10.1371/journal.pone.0075703] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 08/20/2013] [Indexed: 01/03/2023] Open
Abstract
Background Obesity is a risk factor for various types of infectious diseases and cancer. The increase in adipose tissue causes alterations in both adipogenesis and the production of adipocyte-secreted proteins (adipokines). Since natural killer (NK) cells are the host’s primary defense against virus-infected and tumor cells, we investigated how adipocyte-conditioned medium (ACM) affects functions of two distinct human NK cell subsets. Methods Isolated human peripheral blood mononuclear cells (PBMCs) were cultured with various concentrations of human and murine ACM harvested on two different days during adipogenesis and analyzed by fluorescent-activated cell sorting (FACS). Results FACS analyses showed that the expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), granzyme A (GzmA) and interferon (IFN)-γ in NK cells was regulated in a subset-specific manner. ACM treatment altered IFN-γ expression in CD56dim NK cells. The production of GzmA in CD56bright NK cells was differentially affected by the distinct adipokine compositions harvested at different states of adipogenesis. Comparison of the treatment with either human or murine ACM revealed that adipokine-induced effects on NK cell expression of the leptin receptor (Ob-R), TRAIL and IFN-γ were species-specific. Conclusion Considering the growing prevalence of obesity and the various disorders related to it, the present study provides further insights into the roles human NK cell subsets play in the obesity-associated state of chronic low-grade inflammation.
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Affiliation(s)
- Lena Huebner
- Institute for Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Department of General-, Visceral-, Vascular and Thoracic Surgery, Charité, University Medicine Berlin, Campus Mitte, Berlin, Germany
| | - Stefan Engeli
- Institute for Clinical Pharmacology, Hannover Medical School, Hannover, Germany
| | - Christiane D. Wrann
- Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Lilia Goudeva
- Institute for Transfusion Medicine, Hannover Medical School, Hannover, Germany
| | - Tobias Laue
- Institute for Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Heike Kielstein
- Department of Anatomy and Cell Biology, Martin Luther University Halle-Wittenberg, Faculty of Medicine, Halle (Saale), Germany
- * E-mail:
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212
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Morris G, Berk M, Galecki P, Maes M. The emerging role of autoimmunity in myalgic encephalomyelitis/chronic fatigue syndrome (ME/cfs). Mol Neurobiol 2013; 49:741-56. [PMID: 24068616 DOI: 10.1007/s12035-013-8553-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 09/04/2013] [Indexed: 12/13/2022]
Abstract
The World Health Organization classifies myalgic encephalomyelitis/chronic fatigue syndrome (ME/cfs) as a nervous system disease. Together with other diseases under the G93 heading, ME/cfs shares a triad of abnormalities involving elevated oxidative and nitrosative stress (O&NS), activation of immuno-inflammatory pathways, and mitochondrial dysfunctions with depleted levels of adenosine triphosphate (ATP) synthesis. There is also abundant evidence that many patients with ME/cfs (up to around 60 %) may suffer from autoimmune responses. A wide range of reported abnormalities in ME/cfs are highly pertinent to the generation of autoimmunity. Here we review the potential sources of autoimmunity which are observed in people with ME/cfs. The increased levels of pro-inflammatory cytokines, e.g., interleukin-1 and tumor necrosis factor-α, and increased levels of nuclear factor-κB predispose to an autoimmune environment. Many cytokine abnormalities conspire to produce a predominance of effector B cells and autoreactive T cells. The common observation of reduced natural killer cell function in ME/cfs is a source of disrupted homeostasis and prolonged effector T cell survival. B cells may be pathogenic by playing a role in autoimmunity independent of their ability to produce antibodies. The chronic or recurrent viral infections seen in many patients with ME/cfs can induce autoimmunity by mechanisms involving molecular mimicry and bystander activation. Increased bacterial translocation, as observed in ME/cfs, is known to induce chronic inflammation and autoimmunity. Low ATP production and mitochondrial dysfunction is a source of autoimmunity by inhibiting apoptosis and stimulating necrotic cell death. Self-epitopes may be damaged by exposure to prolonged O&NS, altering their immunogenic profile and become a target for the host's immune system. Nitric oxide may induce many faces of autoimmunity stemming from elevated mitochondrial membrane hyperpolarization and blockade of the methionine cycle with subsequent hypomethylation of DNA. Here we also outline options for treatment involving rituximab and endotherapia.
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213
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Effect of Leptin on Neutrophils Phagocytosis and Lymphocytes Apoptosis Challenge by Listeria monocytogenes and Escherichia coli. Jundishapur J Microbiol 2013. [DOI: 10.5812/jjm.6389] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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214
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Paz-Filho G, Mastronardi C, Franco CB, Wang KB, Wong ML, Licinio J. Leptin: molecular mechanisms, systemic pro-inflammatory effects, and clinical implications. ACTA ACUST UNITED AC 2013; 56:597-607. [PMID: 23329181 DOI: 10.1590/s0004-27302012000900001] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2012] [Accepted: 10/24/2012] [Indexed: 12/13/2022]
Abstract
Leptin, the adipokine produced mainly by the white adipose tissue, plays important roles not only in the regulation of food intake, but also in controlling immunity and inflammation. It has been widely demonstrated that the absence of leptin leads to immune defects in animal and human models, ultimately increasing mortality. Leptin also regulates inflammation by means of actions on its receptor, that is widely spread across different immune cell populations. The molecular mechanisms by which leptin determines its biological actions have also been recently elucidated, and three intracellular pathways have been implicated in leptin actions: JAK-STAT, PI3K, and ERK 1/2. These pathways are closely regulated by intracellular proteins that decrease leptin biological activity. In this review, we discuss the molecular mechanisms by which leptin regulates immunity and inflammation, and associate those mechanisms with chronic inflammatory disorders.
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215
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Hristova MG. Metabolic syndrome--from the neurotrophic hypothesis to a theory. Med Hypotheses 2013; 81:627-34. [PMID: 23899630 DOI: 10.1016/j.mehy.2013.07.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 07/08/2013] [Indexed: 02/06/2023]
Abstract
Metabolic syndrome (MetS) is a complex and heterogeneous disease characterized by central obesity, impaired glucose metabolism, dyslipidemia, arterial hypertension, insulin resistance and high-sensitivity C-reactive protein. In 2006, a neurotrophic hypothesis of the etiopathogenesis of MetS was launched. This hypothesis considered the neurotrophins a key factor in MetS development. Chronic inflammatory and/or psychoemotional distress provoke a series of neuroimmunoendocrine interactions such as increased tissue and plasma levels of proinflammatory cytokines and neurotrophins, vegetodystonia, disbalance of neurotransmitters, hormones and immunity markers, activation of the hypothalamo-pituitary-adrenal axis, insulin resistance, and atherosclerosis. An early and a late clinical stage in the course of MetS are defined. Meanwhile, evidence of supporting results from the world literature accumulates. This enables the transformation of the definition of the neurotrophic hypothesis into a neurotrophic theory of MetS. The important role of two neurotrophic factors, i.e. the nerve growth factor and brain-derived neurotrophic factor as well as of the proinflammatory cytokines, neurotransmitters, adipokines and, especially, of leptin for the development of MetS, obesity and type 2 diabetes mellitus is illustrated. There are reliable scientific arguments that the metabotrophic deficit due to reduced neurotrophins could be implicated in the pathogenesis of MetS, type 2 diabetes mellitus, and atherosclerosis as well. A special attention is paid to the activity of the hypothalamo-pituitary-adrenal axis after stress. The application of the neurotrophic theory of MetS could contribute to the etiological diagnosis and individualized management of MetS by eliminating the chronic distress, hyponeurotrophinemia and consequent pathology. It helps estimating the risk, defining the prognosis and implementing the effective prevention of this socially significant disease as evidenced by the dramatic recent growth of the world publication output on this interdisciplinary topic.
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Affiliation(s)
- M G Hristova
- Division of Endocrinology, Medical Centre of Varna, Varna, Bulgaria.
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216
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Beydon N, Delclaux C. BMI as a comorbidity factor in childhood asthma. Expert Rev Respir Med 2013; 6:569-71. [PMID: 23234442 DOI: 10.1586/ers.12.66] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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217
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Holzman C, Senagore PK, Wang J. Mononuclear leukocyte infiltrate in extraplacental membranes and preterm delivery. Am J Epidemiol 2013; 177:1053-64. [PMID: 23429723 DOI: 10.1093/aje/kws351] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Large numbers of polymorphonuclear leukocytes in the amnion and chorion define histological chorioamnionitis (HCA), a condition linked to spontaneous preterm delivery (PTD). Less is known about placental patterns of mononuclear leukocyte (MNL) density and PTD. In this prospective study (1998-2004), women were sampled from 52 clinics in 5 Michigan communities and enrolled at 16-27 weeks' gestation. HCA and MNL distributions in delivered placentas were evaluated microscopically in a subcohort (290 preterm, 823 term). Midpregnancy biomarkers from maternal blood (i.e., C-reactive protein (CRP), corticotropin-releasing hormone, and cytokines) were compared among term and PTD subjects grouped by presence/absence of HCA and high MNL density. A density of more than 10 MNLs per high-power field in the chorion of the membrane roll, referred to as MNL-CMR, was associated with medically indicated PTD (odds ratio = 2.2, 95% confidence interval: 1.3, 3.6) and spontaneous PTD (odds ratio = 2.5, 95% confidence interval: 1.7, 3.7). Associations persisted after removal of women with HCA-positive placentas, abruption, hypertensive disorders, or obesity. HCA-associated PTD showed higher CRP and cytokine levels. MNL-CMR-associated PTD showed higher CRP and corticotropin-releasing hormone levels. These data suggest that an MNL infiltrate in the chorion of the membrane roll marks PTD pathways that are distinct from HCA and not entirely explained by pregnancy complications.
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Affiliation(s)
- Claudia Holzman
- Department of Epidemiology and Biostatistics, College of Human Medicine, Michigan State University, West Fee Hall, 909 Fee Road, Room B601, East Lansing, MI 48824, USA.
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Manuel-Apolinar L, López-Romero R, Zarate A, Damasio L, Ruiz M, Castillo-Hernández C, Guevara G, Mera-Jiménez E. Leptin mediated ObRb receptor increases expression of adhesion intercellular molecules and cyclooxygenase 2 on murine aorta tissue inducing endothelial dysfunction. Int J Clin Exp Med 2013; 6:192-196. [PMID: 23573350 PMCID: PMC3609695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 03/02/2013] [Indexed: 06/02/2023]
Abstract
There are several reports showing that hyperleptinemia positively correlates with atherogenic process including promotion of platelet aggregation, thrombosis, and production of inflammatory cytokines. Thereby endothelial dysfunction takes place and underlies metabolic and vascular alterations that contribute to the development of both cardiovascular disease and type 2 diabetes. It has been also proposed that endothelial dysfunction may antecede the development of insulin resistance and diabetes. Endothelial cells participate in vasoregulation by the modulation of nitric oxide production and prostaglandin; in addition these cells are major vector in angiogenesis and recruitment of leukocytes and adhesion molecules. Nevertheless mechanisms underlying vascular dysfunction remain to be fully elucidated. This experiment in vitro revealed that the addition of leptin to cultivated endothelial cells elicited a significant molecular expression of both COX 2 and ICAM-1: in addition, the response showed a positive relationship with leptin concentration and the time of incubation. Thus, it may be suggested that leptin acts directly on the endothelium by activating its specific receptor which in turn initiates the molecular response related with the production of factors involved in the inflammatory response. Alterations on prostaglandins and recruiting molecules of adhesion are relevant stages of the endothelial damage.
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Affiliation(s)
- Leticia Manuel-Apolinar
- Endocrine Research Unit, Centro Medico Nacional, Instituto Mexicano del Seguro Social (IMSS)Cuauhtemoc 330, Doctores, Mexico City 06270, Mexico
| | - Ricardo López-Romero
- Oncology Research Unit, Centro Medico Nacional, Instituto Mexicano del Seguro Social (IMSS)Cuauhtemoc 330, Doctores, Mexico City 06270, Mexico
| | - Arturo Zarate
- Endocrine Research Unit, Centro Medico Nacional, Instituto Mexicano del Seguro Social (IMSS)Cuauhtemoc 330, Doctores, Mexico City 06270, Mexico
| | - Leticia Damasio
- Endocrine Research Unit, Centro Medico Nacional, Instituto Mexicano del Seguro Social (IMSS)Cuauhtemoc 330, Doctores, Mexico City 06270, Mexico
| | - Miriam Ruiz
- Endocrine Research Unit, Centro Medico Nacional, Instituto Mexicano del Seguro Social (IMSS)Cuauhtemoc 330, Doctores, Mexico City 06270, Mexico
| | - Carmen Castillo-Hernández
- Research and Graduate Studies Section, Instituto Politecnico Nacional (IPN)Cuauhtemoc 330, Doctores, Mexico City 06270, Mexico
| | - Gustavo Guevara
- Research and Graduate Studies Section, Instituto Politecnico Nacional (IPN)Cuauhtemoc 330, Doctores, Mexico City 06270, Mexico
| | - Elvia Mera-Jiménez
- Research and Graduate Studies Section, Instituto Politecnico Nacional (IPN)Cuauhtemoc 330, Doctores, Mexico City 06270, Mexico
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219
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Class II major histocompatibility complex plays an essential role in obesity-induced adipose inflammation. Cell Metab 2013; 17:411-22. [PMID: 23473035 PMCID: PMC3619392 DOI: 10.1016/j.cmet.2013.02.009] [Citation(s) in RCA: 288] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 12/21/2012] [Accepted: 02/12/2013] [Indexed: 01/01/2023]
Abstract
Adipose-resident T cells (ARTs) regulate metabolic and inflammatory responses in obesity, but ART activation signals are poorly understood. Here, we describe class II major histocompatibility complex (MHCII) as an important component of high-fat-diet (HFD)-induced obesity. Microarray analysis of primary adipocytes revealed that multiple genes involved in MHCII antigen processing and presentation increased in obese women. In mice, adipocyte MHCII increased within 2 weeks on HFD, paralleling increases in proinflammatory ART markers and decreases in anti-inflammatory ART markers, and preceding adipose tissue macrophage (ATM) accumulation and proinflammatory M1 polarization. Mouse 3T3-L1 and primary adipocytes activated T cells in an antigen-specific, contact-dependent manner, indicating that adipocyte MHCII is functional. HFD-fed MHCII(-/-) mice developed less adipose inflammation and insulin resistance than did wild-type mice, despite developing similar adiposity. These investigations uncover a mechanism whereby a HFD-induced adipocyte/ART dialog involving MHCII instigates adipose inflammation and, together with ATM MHCII, escalates its progression.
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Abstract
PURPOSE OF REVIEW Dietary n-3 polyunsaturated fatty acids (n-3 PUFAs) may be related to a number of chronic metabolic abnormalities, including metabolic syndrome. This review presents an update on the effects of n-3 PUFAs on risk factors of metabolic syndrome, especially adipose tissue inflammation, oxidative stress and underlying mechanisms of these effects. RECENT FINDINGS Anti-inflammatory actions of n-3 PUFAs are thought to be mediated by the formation of their active metabolites (eicosanoids and other lipid mediators) as well as their regulation of the production of inflammatory mediators (e.g., adipocytokines, cytokines) and immune cell infiltration into adipose tissue. n-3 PUFAs mediate these effects by modulating several pathways, such as those involving nuclear factor-κB, peroxisome proliferator-activated receptors and Toll-like receptors. The antioxidative effects of n-3 PUFAs in adipocytes appear to inhibit reactive oxygen species production and alter mitochondrial function. SUMMARY This review summarizes the evidence for beneficial effects of n-3 PUFAs on adipose tissue inflammation and oxidative stress. More studies are necessary to investigate the mechanisms underlying these effects and to relate this topic to human health.
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Affiliation(s)
- Chaonan Fan
- Key Laboratory of Major Disease in Children and National Key Discipline of Pediatrics (Capital Medical University), Ministry of Education, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, China
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Lamas B, Goncalves-Mendes N, Nachat-Kappes R, Rossary A, Caldefie-Chezet F, Vasson MP, Farges MC. Leptin modulates dose-dependently the metabolic and cytolytic activities of NK-92 cells. J Cell Physiol 2013; 228:1202-9. [DOI: 10.1002/jcp.24273] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Accepted: 10/19/2012] [Indexed: 11/07/2022]
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White SJ, Taylor MJ, Hurt RT, Jensen MD, Poland GA. Leptin-based adjuvants: an innovative approach to improve vaccine response. Vaccine 2013; 31:1666-72. [PMID: 23370154 DOI: 10.1016/j.vaccine.2013.01.032] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Revised: 01/04/2013] [Accepted: 01/15/2013] [Indexed: 12/22/2022]
Abstract
Leptin is a pleiotropic hormone with multiple direct and regulatory immune functions. Leptin deficiency or resistance hinders the immunologic, metabolic, and neuroendocrinologic processes necessary to thwart infections and their associated complications, and to possibly protect against infectious diseases following vaccination. Circulating leptin levels are proportional to body fat mass. High circulating leptin concentrations, as observed in obesity, are indicative of the development of leptin transport saturation/signaling desensitization. Leptin bridges nutritional status and immunity. Although its role in vaccine response is currently unknown, over-nutrition has been shown to suppress vaccine-induced immune responses. For instance, obesity (BMI ≥30 kg/m(2)) is associated with lower antigen-specific antibody titers following influenza, hepatitis B, and tetanus vaccinations. This suggests that obesity, and possibly saturable leptin levels, are contributing factors to poor vaccine immunogenicity. While leptin-based therapies have not been investigated as vaccine adjuvants thus far, leptin's role in immunity suggests that application of these therapies is promising and worth investigation to enhance vaccine response in people with leptin signaling impairments. This review will examine the possibility of using leptin as a vaccine adjuvant by: briefly reviewing the distribution and signal transduction of leptin and its receptors; discussing the physiology of leptin with emphasis on its immune functions; reviewing the causes of attenuation of leptin signaling; and finally, providing plausible inferences for the innovative use of leptin-based pharmacotherapies as vaccine adjuvants.
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Affiliation(s)
- Sarah J White
- Mayo Clinic Vaccine Research Group, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States
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Adaptive immunity alters distinct host feeding pathways during nematode induced inflammation, a novel mechanism in parasite expulsion. PLoS Pathog 2013; 9:e1003122. [PMID: 23349631 PMCID: PMC3547840 DOI: 10.1371/journal.ppat.1003122] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 11/26/2012] [Indexed: 12/18/2022] Open
Abstract
Gastrointestinal infection is often associated with hypophagia and weight loss; however, the precise mechanisms governing these responses remain poorly defined. Furthermore, the possibility that alterations in feeding during infection may be beneficial to the host requires further study. We used the nematode Trichinella spiralis, which transiently inhabits the small intestine before migrating to skeletal muscle, as a biphasic model of infection to determine the cellular and molecular pathways controlling feeding during enteric and peripheral inflammation. Through the infection of genetically modified mice lacking cholecystokinin, Tumor necrosis factor α receptors and T and B-cells, we observed a biphasic hypophagic response to infection resulting from two separate immune-driven mechanisms. The enteroendocrine I-cell derived hormone cholecystokinin is an essential mediator of initial hypophagia and is induced by CD4+ T-cells during enteritis. In contrast, the second hypophagic response is extra-intestinal and due to the anorectic effects of TNFα during peripheral infection of the muscle. Moreover, via maintaining naive levels of the adipose secreted hormone leptin throughout infection we demonstrate a novel feedback loop in the immunoendocrine axis. Immune driven I-cell hyperplasia and resultant weight loss leads to a reduction in the inflammatory adipokine leptin, which in turn heightens protective immunity during infection. These results characterize specific immune mediated mechanisms which reduce feeding during intestinal or peripheral inflammation. Importantly, the molecular mediators of each phase are entirely separate. The data also introduce the first evidence that I-cell hyperplasia is an adaptively driven immune response that directly impinges on the outcome to infection. Infection with intestinal parasites often results in a period of reduced appetite which can result in weight loss; however the factors which control these feeding alterations and the reason why they occur is unknown. We used the nematode parasite Trichinella spiralis, which during its life cycle causes intestinal and muscular inflammation, as a mouse infection model to study the factors which alter feeding during infection. We found that the mouse immune response to the parasite was driving two periods of reduced feeding by two distinct immune mediators during the intestinal and muscular periods of infection. Interestingly, the immune system was utilizing a hormone which usually terminates feeding during our daily meals to cause a reduction in weight and fat deposits. Furthermore, we found that a reduction in these fat deposits and their associated hormones actually helped the mouse expel the parasite from the intestine. Hence the immune driven weight loss was actually beneficial to the mouse's ability to resolve an infection. Our study provides novel insights into how the immune system interacts with feeding pathways during intestinal inflammation and may help us design new strategies for helping people with parasitic infections of the gut.
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Abstract
T cell activation leads to dramatic shifts in cell metabolism to protect against pathogens and to orchestrate the action of other immune cells. Quiescent T cells require predominantly ATP-generating processes, whereas proliferating effector T cells require high metabolic flux through growth-promoting pathways. Further, functionally distinct T cell subsets require distinct energetic and biosynthetic pathways to support their specific functional needs. Pathways that control immune cell function and metabolism are intimately linked, and changes in cell metabolism at both the cell and system levels have been shown to enhance or suppress specific T cell functions. As a result of these findings, cell metabolism is now appreciated as a key regulator of T cell function specification and fate. This review discusses the role of cellular metabolism in T cell development, activation, differentiation, and function to highlight the clinical relevance and opportunities for therapeutic interventions that may be used to disrupt immune pathogenesis.
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Affiliation(s)
- Nancie J MacIver
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina 27710, USA
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225
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Al-Fadhli M, Saraya M, Qasem J, Azizieh F, Shahab S, Raghupathy R. Relationship between leptin levels and suppressed CD4 counts in HIV patients. Med Princ Pract 2013; 22:54-8. [PMID: 22722316 PMCID: PMC5586700 DOI: 10.1159/000339201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 04/25/2012] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE To examine the relationship between serum leptin levels and suppression of CD4 count in HIV-infected individuals with highly active antiretroviral therapy (HAART). SUBJECTS AND METHODS Thirty seropositive HIV male patients selected from the Infectious Disease Hospital were classified into two groups according to their immunological and virological response to HAART. The first group included 15 male patients with low viral load and low CD4 counts; the second included 15 male patients with low viral load and high CD4 counts. Morning serum leptin and tumor necrosis factor-α levels of HIV patients were measured and correlated with fasting serum insulin, Homeostasis Model Assessment for Insulin Resistance (HOMA-IR), HIV viral load and CD4 count. RESULTS Serum leptin levels were significantly higher in patients with high CD4 counts than in patients with low CD4 counts (mean serum leptin level 47.3 vs. 10.9 ng/ml, respectively; p < 0.0001). A positive correlation was observed between serum leptin levels and CD4 counts (r = 0.697; p < 0.0001); positive correlations were also seen between leptin levels and fasting serum insulin and HOMA-IR (r = 0.633, p < 0.0001, and r = 0.537, p < 0.003, respectively). CONCLUSION Serum leptin level was higher in HIV patients with high CD4 count and correlated with fasting serum insulin and HOMA-IR, thereby indicating that HAART treatment could lead to decreased levels of leptin in HIV patients, which might lead to impaired immunological recovery.
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Affiliation(s)
- Mariam Al-Fadhli
- Department of Tropical Medicine, Faculty of Medicine, Zagazig University, Zagazig City, Egypt.
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226
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Eftekhari E, Etemadifar M, Ebrahimi A, Baradaran S. The relation between peptide hormones and sex hormone in patients with multiple sclerosis. IRANIAN JOURNAL OF NEUROLOGY 2013; 12:60-5. [PMID: 24250904 PMCID: PMC3829283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 02/12/2013] [Indexed: 11/30/2022]
Abstract
BACKGROUND Hormones can play a significant role in the pathogenesis of multiple sclerosis (MS). The aim of this study was to compare levels of ghrelin, leptin, and testosterone hormones of MS patients with healthy subjects, and assess the relationship between levels of peptide hormone and sex hormones in MS patients. METHODS 35 MS patients with definite relapsing remitting multiple sclerosis (RRMS) (male = 9, female = 26) and 13 healthy subjects (male = 4, female = 9) were enrolled in the study. Levels of serum ghrelin, leptin, and testosterone hormones were measured in this study. ANOVA and Pearson correlation were used for data analysis (P < 0.05). RESULTS The female and male participants of the patient group were compared with the healthy group. No significant differences were found in serum of leptin, ghrelin, testosterone, ghrelin/leptin, and testosterone/leptin (P < 0.05). Spearman correlation coefficient showed that leptin had a significant negative correlation with the variability of testosterone (r = -1.00) in the healthy male group. Moreover, leptin had a significant positive correlation with the variability of BMI (r = 0.68) and weight (r = 0.59), at the 0.01 level (2-tailed), in the female patient group. In addition, in the healthy male group, ghrelin had a significant negative correlation with the variability of weight (r = -1.00). CONCLUSION According to the results, there was no significant difference between peptide and sex hormones of MS patients and healthy persons. Furthermore, there was no significant relationship between peptide and sex hormones of MS patients and healthy persons.
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Affiliation(s)
- Elham Eftekhari
- Assistant Professor, Department of Physical Education and Sport Sciences, Islamic Azad University, Najafabad Branch, Isfahan, Iran
| | - Masoud Etemadifar
- Neurologist, Isfahan Eye Research Center (IERC) AND Department of Neurology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Ali Ebrahimi
- Isfahan Research Committee of Multiple Sclerosis, Isfahan University of Medical Sciences, Isfahan, Iran
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227
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Impairment of proliferation and NK activity of spleen leucocytes in young rats treated with a leptin antagonist during the physiological leptin surge through postnatal days 5–10. Proc Nutr Soc 2013. [DOI: 10.1017/s0029665113000864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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228
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Falor AE, Zobel M, Kaji A, Neville A, De Virgilio C. Admission variables predictive of gangrenous cholecystitis. Am Surg 2012; 22:1648-57. [PMID: 23025944 DOI: 10.1007/s11695-012-0698-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The objective of the present study was to identify admission clinical factors associated with gangrenous cholecystitis (GC) and factors associated with conversion to open cholecystectomy. We retrospectively evaluated 391 patients over a 17-month period who underwent urgent laparoscopic cholecystectomy for a diagnosis of acute cholecystitis. Eighty-nine patients with pathologically proven GC were compared with 302 patients without GC. On multivariable logistic regression, predictors of GC included male gender, white blood cell count greater than 14,000/mm3, heart rate greater than 90 beats per minute, and sodium 135 mg/dL or less. Conversion rate to open cholecystectomy was 7.9 per cent overall, 4 per cent for non-GC, and 19 per cent for GC (odds ratio, 0.2; 95% confidence interval, 0.1 to 0.4; P<0.00001). Conversion was predicted by increasing number of days to surgery, total bilirubin, and white blood cell count. Complication rate was higher in the GC group (10.1 vs 3.6% in the acute cholecystitis group, P=0.01). The increased rate of conversion observed with surgery delay suggests that early laparoscopic cholecystectomy may be preferable in most patients.
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Affiliation(s)
- Ann E Falor
- Department of Surgery, Harbor-UCLA Medical Center, Torrance, California 90509, USA
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229
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Burgos-Ramos E, Sackmann-Sala L, Baquedano E, Cruz-Topete D, Barrios V, Argente J, Kopchick JJ. Central leptin and insulin administration modulates serum cytokine- and lipoprotein-related markers. Metabolism 2012; 61:1646-57. [PMID: 22658937 DOI: 10.1016/j.metabol.2012.05.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 04/12/2012] [Accepted: 05/01/2012] [Indexed: 10/28/2022]
Abstract
UNLABELLED In most obese patients there is an inflammatory state characterized by lipid abnormalities, hyperleptinemia and hyperinsulinemia. OBJECTIVE The objective was to identify mechanisms involved in leptin's role in the attenuation of the response to insulin using a proteomic approach. MATERIAL/METHODS We studied the serum proteomic profile of rats treated by central leptin infusion followed by an injection of insulin. We analyzed the relationship between these proteins and serum cytokine and apolipoprotein levels. RESULTS Out of 81 protein spots, intensity differences were found in 11, corresponding to 5 proteins: three isoforms of α1 macroglobulin; three of haptoglobin and serum amyloid P component-precursor. All of these are acute-phase proteins involved in inflammation and are correlated with cytokine levels. Additionally, two apolipoprotein E and two apolipoprotein A1 isoforms were identified and were found to correlate with LDL and HDL. CONCLUSIONS Our results indicate that increased leptin and insulin levels change these circulating proteins, thus promoting systemic inflammation and changing lipid metabolism.
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Affiliation(s)
- Emma Burgos-Ramos
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto Investigación Sanitaria Princesa, Madrid, E-28009 Spain
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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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Burgos-Ramos E, Canelles S, Perianes-Cachero A, Arilla-Ferreiro E, Argente J, Barrios V. Adipose tissue promotes a serum cytokine profile related to lower insulin sensitivity after chronic central leptin infusion. PLoS One 2012; 7:e46893. [PMID: 23056516 PMCID: PMC3462753 DOI: 10.1371/journal.pone.0046893] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 09/10/2012] [Indexed: 12/13/2022] Open
Abstract
Obesity is an inflammatory state characterized by an augment in circulating inflammatory factors. Leptin may modulate the synthesis of these factors by white adipose tissue decreasing insulin sensitivity. We have examined the effect of chronic central administration of leptin on circulating levels of cytokines and the possible relationship with cytokine expression and protein content as well as with leptin and insulin signaling in subcutaneous and visceral adipose tissues. In addition, we analyzed the possible correlation between circulating levels of cytokines and peripheral insulin resistance. We studied 18 male Wistar rats divided into controls (C), those treated icv for 14 days with a daily dose of 12 μg of leptin (L) and a pair-fed group (PF) that received the same food amount consumed by the leptin group. Serum leptin and insulin were measured by ELISA, mRNA levels of interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-4, IL-6, IL-10 and tumor necrosis factor-α (TNF-α) by real time PCR and serum and adipose tissue levels of these cytokines by multiplexed bead immunoassay. Serum leptin, IL-2, IL-4, IFN-γ and HOMA-IR were increased in L and TNF-α was decreased in PF and L. Serum leptin and IL-2 levels correlate positively with HOMA-IR index and negatively with serum glucose levels during an ip insulin tolerance test. In L, an increase in mRNA levels of IL-2 was found in both adipose depots and IFN-γ only in visceral tissue. Activation of leptin signaling was increased and insulin signaling decreased in subcutaneous fat of L. In conclusion, leptin mediates the production of inflammatory cytokines by adipose tissue independent of its effects on food intake, decreasing insulin sensitivity.
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Affiliation(s)
- Emma Burgos-Ramos
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa and Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Sandra Canelles
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa and Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Arancha Perianes-Cachero
- Grupo de Neurobioquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad de Alcalá, Alcalá de Henares, Spain
| | - Eduardo Arilla-Ferreiro
- Grupo de Neurobioquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad de Alcalá, Alcalá de Henares, Spain
| | - Jesús Argente
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa and Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Vicente Barrios
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa and Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- * E-mail:
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Yurt S, Erman H, Korkmaz GG, Kosar AF, Uysal P, Gelisgen R, Simsek G, Uzun H. The role of feed regulating peptides on weight loss in patients with pulmonary tuberculosis. Clin Biochem 2012; 46:40-4. [PMID: 23000316 DOI: 10.1016/j.clinbiochem.2012.09.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Revised: 09/10/2012] [Accepted: 09/11/2012] [Indexed: 12/19/2022]
Abstract
PURPOSE Malnutrition is a prominent feature of tuberculosis (TB). The aim of our study was to explore the function of plasma regulatory proteins in pulmonary TB and to investigate the relationship between these parameters and loss of body weight. METHODS Plasma levels of fasting insulin, leptin, ghrelin, adiponectin and orexin-A were measured in 23 pulmonary TB patients, 39 patients with pulmonary sarcoidosis, 22 patients with different diffuse interstitial lung diseases and 21 healthy patients serving as controls. RESULT Plasma leptin (p<0.001) and orexin-A (p<0.01) levels were significantly decreased in TB patients compared with those of the other study subjects. TB patients also had higher levels of plasma ghrelin compared with those of the other study subjects, while sarcoidosis patients had higher plasma adiponectin levels than the other study subjects. Glucose levels were similar in all groups, yet, insulin and Homeostasis Model of Assessment-Insulin Resistance (HOMA-IR) levels were significantly higher in the TB group compared to the other study groups. There was no correlation between leptin, ghrelin, adiponectin and orexin-A and other parameters. CONCLUSIONS These data suggest that leptin and orexin-A levels have effects on weight loss in patients with pulmonary tuberculosis. Particularly, leptin may play a role in the early immune response to pulmonary TB and prolonged inflammation may further suppress leptin production. Measurement of HOMA-IR can indeed be used as a marker for the risk of activated TB. Further clinical studies are needed to better understand the role of feed regulating proteins in pulmonary tuberculosis.
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Affiliation(s)
- S Yurt
- Yedikule Chest Disease and Chest Surgery Education and Research Hospital, Istanbul, Turkey.
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Abstract
Enhanced susceptibility to infection has long been recognized in children with congenital deficiency of leptin or its receptor. Studies in mice have demonstrated that leptin deficiency affects both the innate and acquired immune systems. Here, we review recent studies that demonstrate the impact on immunity of a common non-synonomous polymorphism of the leptin receptor. In a Bangladesh cohort of children, the presence of two copies of the ancestral Q223 allele was significantly associated with resistance to amebiasis. Children and mice with at least one copy of the leptin receptor 223R mutation were more susceptible to amebic colitis. Leptin signaling in the intestinal epithelium and downstream STAT3 (signal transducer and activator of transcription 3) and SHP2 (Src homology phosphatase 2) signaling were required for protection in the murine model of amebic colitis. Murine models have also implicated leptin in protection from other infections, including Mycobacterium tuberculosis, Klebsiella pneumoniae, and Streptococcus pneumoniae. Thus, the role of leptin signaling in infectious disease and specifically leptin-mediated protection of the intestinal epithelium will be the focus of this review.
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234
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Oliveira M, Assis DM, Paschoalin T, Miranda A, Ribeiro EB, Juliano MA, Brömme D, Christoffolete MA, Barros NMT, Carmona AK. Cysteine cathepsin S processes leptin, inactivating its biological activity. J Endocrinol 2012; 214:217-24. [PMID: 22653842 DOI: 10.1530/joe-12-0108] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Leptin is a 16 kDa hormone mainly produced by adipocytes that plays an important role in many biological events including the regulation of appetite and energy balance, atherosclerosis, osteogenesis, angiogenesis, the immune response, and inflammation. The search for proteolytic enzymes capable of processing leptin prompted us to investigate the action of cysteine cathepsins on human leptin degradation. In this study, we observed high cysteine peptidase expression and hydrolytic activity in white adipose tissue (WAT), which was capable of degrading leptin. Considering these results, we investigated whether recombinant human cysteine cathepsins B, K, L, and S were able to degrade human leptin. Mass spectrometry analysis revealed that among the tested enzymes, cathepsin S exhibited the highest catalytic activity on leptin. Furthermore, using a Matrigel assay, we observed that the leptin fragments generated by cathepsin S digestion did not exhibit angiogenic action on endothelial cells and were unable to inhibit food intake in Wistar rats after intracerebroventricular administration. Taken together, these results suggest that cysteine cathepsins may be putative leptin activity regulators in WAT.
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Affiliation(s)
- Marcela Oliveira
- Departamento de Biofísica, Universidade Federal de São Paulo, Rua Pedro de Toledo 669, São Paulo, São Paulo 04039-032, Brazil
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235
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Dietary flaxseed oil reduces adipocyte size, adipose monocyte chemoattractant protein-1 levels and T-cell infiltration in obese, insulin-resistant rats. Cytokine 2012; 59:382-91. [DOI: 10.1016/j.cyto.2012.04.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 03/13/2012] [Accepted: 04/06/2012] [Indexed: 12/14/2022]
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236
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Mouzaki A, Panagoulias I, Raptis G, Farri-Kostopoulou E. Cord blood leptin levels of healthy neonates are associated with IFN-γ production by cord blood T-cells. PLoS One 2012; 7:e40830. [PMID: 22815836 PMCID: PMC3397963 DOI: 10.1371/journal.pone.0040830] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 06/15/2012] [Indexed: 11/19/2022] Open
Abstract
Leptin is a hormone synthesized by adipocytes and other tissues, including the placenta, and it regulates food intake and energy expenditure, reproductive and immune functions. To investigate the role of leptin in neonatal immunity, we measured serum leptin and cytokine (IFN-γ, TNF-α, IL-2, IL-4, IL-10, IL-12) levels in the cord blood (cb) of 510 healthy neonates, 14 small for gestational age (SGA), 312 appropriately grown for gestational age (AGA) and 184 large for gestational age (LGA). Median serum leptin concentration in the whole sample was 11 ng/ml. In 11.2% neonates (1 SGA, 32 AGA, 24 LGA), leptin levels were >90th percentile (median 39 ng/ml). In 33.3% of those (3.72% of total sample) with the highest leptin levels (median 46 ng/ml), significantly elevated levels of serum IFN-γ were also found (mean 27.11 pg/ml, range 17.5-38.5 pg/ml). In neonates with leptin levels ∼50th percentile (median 12 ng/ml) or <10th percentile (median 1 ng/ml), serum IFN-γ levels were negligible. All other cytokines measured, were < the assays' detection limits. To investigate whether leptin can independently influence cytokine gene expression by cb T-cells and monocytes (Mc), we cultured cb T-cells or Mc, isolated from randomly selected AGA neonates or adult peripheral blood, with leptin. This resulted in upregulation of IL-2, IFN-γ and IL-4 gene expression in cb and adult T-cells and IL-10 expression mainly in cb-Mc. Significantly higher expression of IFN-γ occurred in female cb-T-cells cultured with leptin, compared with male cb-T-cells. In conclusion, the concurrent presence of high concentrations in both leptin and IFN-γ in cb of healthy infants, and leptin's ability to directly upregulate cytokine gene expression in cb T and Mc cells, indicate that abnormally high leptin levels can independently influence the immune system of healthy newborns, and may mediate gender differences in the development of a Th1 polarized immune response.
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Affiliation(s)
- Athanasia Mouzaki
- Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras, Greece.
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237
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Ueno T, Wada S, Mashita S, Kuwano A, Katayama Y. Pathological Findings in a Case of Equine T-Cell Lymphoma Associated with Ataxia. J Equine Vet Sci 2012. [DOI: 10.1016/j.jevs.2011.11.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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238
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Mancuso P. Obesity and respiratory infections: does excess adiposity weigh down host defense? Pulm Pharmacol Ther 2012; 26:412-9. [PMID: 22634305 DOI: 10.1016/j.pupt.2012.04.006] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2012] [Revised: 03/23/2012] [Accepted: 04/23/2012] [Indexed: 12/21/2022]
Abstract
The number of overweight and obese individuals has dramatically increased in the US and other developed nations during the past 30 years. While type II diabetes and cardiovascular disease are well recognized co-morbid conditions associated with obesity, recent reports have demonstrated a greater severity of illness in obese patients due to influenza during the 2009 H1N1 pandemic. Consistent with these reports, diet-induced obesity has been shown to impair anti-viral host defense in murine models of influenza infection. However, the impact of obesity on the risk of community-acquired and nosocomial pneumonia in human patients is not clear. Relatively few studies have evaluated the influence of diet-induced obesity in murine models of bacterial infections of the respiratory tract. Obese leptin deficient humans and leptin and leptin-receptor deficient mice exhibit greater susceptibility to respiratory infections suggesting a requirement for leptin in the pulmonary innate and adaptive immune response to infection. In contrast to these studies, we have observed that obese leptin receptor signaling mutant mice are resistant to pneumococcal pneumonia highlighting the complex interaction between leptin receptor signaling and immune function. Given the increased prevalence of obesity and poor responsiveness of obese individuals to vaccination against influenza, the development of novel immunization strategies for this population is warranted. Additional clinical and animal studies are needed to clarify the relationship between increased adiposity and susceptibility to community-acquired and nosocomial pneumonia.
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Affiliation(s)
- Peter Mancuso
- Department of Environmental Health Sciences and the Graduate Program in Immunology, 109 S Observatory Street, School of Public Health, University of Michigan, 6627 SPH1A, Ann Arbor, MI 48109-2029, USA.
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239
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Slee AD. Exploring metabolic dysfunction in chronic kidney disease. Nutr Metab (Lond) 2012; 9:36. [PMID: 22537670 PMCID: PMC3407016 DOI: 10.1186/1743-7075-9-36] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Accepted: 04/26/2012] [Indexed: 02/07/2023] Open
Abstract
Impaired kidney function and chronic kidney disease (CKD) leading to kidney failure and end-stage renal disease (ESRD) is a serious medical condition associated with increased morbidity, mortality, and in particular cardiovascular disease (CVD) risk. CKD is associated with multiple physiological and metabolic disturbances, including hypertension, dyslipidemia and the anorexia-cachexia syndrome which are linked to poor outcomes. Specific hormonal, inflammatory, and nutritional-metabolic factors may play key roles in CKD development and pathogenesis. These include raised proinflammatory cytokines, such as interleukin-1 and −6, tumor necrosis factor, altered hepatic acute phase proteins, including reduced albumin, increased C-reactive protein, and perturbations in normal anabolic hormone responses with reduced growth hormone-insulin-like growth factor-1 axis activity. Others include hyperactivation of the renin-angiotensin aldosterone system (RAAS), with angiotensin II and aldosterone implicated in hypertension and the promotion of insulin resistance, and subsequent pharmacological blockade shown to improve blood pressure, metabolic control and offer reno-protective effects. Abnormal adipocytokine levels including leptin and adiponectin may further promote the insulin resistant, and proinflammatory state in CKD. Ghrelin may be also implicated and controversial studies suggest activities may be reduced in human CKD, and may provide a rationale for administration of acyl-ghrelin. Poor vitamin D status has also been associated with patient outcome and CVD risk and may indicate a role for supplementation. Glucocorticoid activities traditionally known for their involvement in the pathogenesis of a number of disease states are increased and may be implicated in CKD-associated hypertension, insulin resistance, diabetes risk and cachexia, both directly and indirectly through effects on other systems including activation of the mineralcorticoid receptor. Insight into the multiple factors altered in CKD may provide useful information on disease pathogenesis, clinical assessment and treatment rationale such as potential pharmacological, nutritional and exercise therapies.
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Affiliation(s)
- Adrian D Slee
- School of Life Sciences, Brayford Pool Campus, University of Lincoln, Lincoln, UK.
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Abstract
Recent findings on the role of transforming growth factor (TGF)-β/Smad3 signaling in the pathogenesis of obesity and type 2 diabetes have underscored its importance in metabolism and adiposity. Indeed, elevated TGF-β has been previously reported in human adipose tissue during morbid obesity and diabetic neuropathy. In this review, we discuss the pleiotropic effects of TGF-β/Smad3 signaling on metabolism and energy homeostasis, all of which has an important part in the etiology and progression of obesity-linked diabetes; these include adipocyte differentiation, white to brown fat phenotypic transition, glucose and lipid metabolism, pancreatic function, insulin signaling, adipocytokine secretion, inflammation and reactive oxygen species production. We summarize the recent in vivo findings on the role of TGF-β/Smad3 signaling in metabolism based on the studies using Smad3−/− mice. Based on the presence of a dual regulatory effect of Smad3 on peroxisome proliferator-activated receptor (PPAR)β/δ and PPARγ2 promoters, we propose a unifying mechanism by which this signaling pathway contributes to obesity and its associated diabetes. We also discuss how the inhibition of this signaling pathway has been implicated in the amelioration of many facets of metabolic syndromes, thereby offering novel therapeutic avenues for these metabolic conditions.
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Affiliation(s)
- C K Tan
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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241
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Gutierrez DA, Hasty AH. Haematopoietic leptin receptor deficiency does not affect macrophage accumulation in adipose tissue or systemic insulin sensitivity. J Endocrinol 2012; 212:343-51. [PMID: 22194312 PMCID: PMC3381898 DOI: 10.1530/joe-11-0338] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The adipokine leptin is primarily produced by white adipose tissue (AT) and is a potent monocyte/macrophage chemoattractant in vitro. The long form of the leptin receptor (LepR) is required for monocyte/macrophage chemotaxis towards leptin. In this study, we examined the effects of haematopoietic LepR as well as LepR with C-C chemokine receptor 2 (CCR2) deficiency (double knockout (DKO)) on macrophage recruitment to AT after two different periods of high fat diet (HFD) feeding. Briefly, 8-week-old C57BL/6 mice were transplanted with bone marrow (BM) from Lepr(+/+), Lepr(-/-) or DKO donors (groups named BM-Lepr(+/+), BM-Lepr(-/-) and BM-DKO respectively), and were placed on an HFD for 6 or 12 weeks. At the end of the study, macrophage infiltration and the inflammatory state of AT were evaluated by real-time RT-PCR, histology and flow cytometry. In addition, glucose and insulin tolerance were assessed at both time points. Our results showed no differences in macrophage accumulation or AT inflammatory state between the BM-Lepr(+/+) and BM-Lepr(-/-) mice after 6 or 12 weeks of HFD feeding; any effects observed in the BM-DKO were attributed to the haematopoietic deficiency of CCR2. In addition, no changes in glucose or insulin tolerance were observed between groups after either period of HFD feeding. Our findings suggest that although leptin is a potent chemoattractant in vitro, haematopoietic LepR deficiency does not affect macrophage accumulation in AT in early to moderate stages of diet-induced obesity.
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Affiliation(s)
| | - Alyssa H. Hasty
- Corresponding Author Alyssa H. Hasty Room 702 Light Hall, Nashville, TN 37232-0615 Phone: 615-322-5177 Fax: 615-322-8973
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242
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Alcazar MAA, Boehler E, Rother E, Amann K, Vohlen C, von Hörsten S, Plank C, Dötsch J. Early postnatal hyperalimentation impairs renal function via SOCS-3 mediated renal postreceptor leptin resistance. Endocrinology 2012; 153:1397-410. [PMID: 22253420 DOI: 10.1210/en.2011-1670] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Early postnatal hyperalimentation has long-term implications for obesity and developing renal disease. Suppressor of cytokine signaling (SOCS) 3 inhibits phosphorylation of signal transducer and activator of transcription (STAT) 3 and ERK1/2 and thereby plays a pivotal role in mediating leptin resistance. In addition, SOCS-3 is induced by both leptin and inflammatory cytokines. However, little is known about the intrinsic-renal leptin synthesis and function. Therefore, this study aimed to elucidate the implications of early postnatal hyperalimentation on renal function and on the intrinsic-renal leptin signaling. Early postnatal hyperalimentation in Wistar rats during lactation was induced by litter size reduction at birth (LSR) either to LSR10 or LSR6, compared with home cage control male rats. Assessment of renal function at postnatal day 70 revealed decreased glomerular filtration rate and proteinuria after LSR6. In line with this impairment of renal function, renal inflammation and expression as well as deposition of extracellular matrix molecules, such as collagen I, were increased. Furthermore, renal expression of leptin and IL-6 was up-regulated subsequent to LSR6. Interestingly, the phosphorylation of Stat3 and ERK1/2 in the kidney, however, was decreased after LSR6, indicating postreceptor leptin resistance. In accordance, neuropeptide Y (NPY) gene expression was down-regulated; moreover, SOCS-3 protein expression, a mediator of postreceptor leptin resistance, was strongly elevated and colocalized with NPY. Thus, our findings not only demonstrate impaired renal function and profibrotic processes but also provide compelling evidence of a SOCS-3-mediated intrinsic renal leptin resistance and concomitant up-regulated NPY expression as an underlying mechanism.
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243
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McCaskey SJ, Rondini EA, Langohr IM, Fenton JI. Differential effects of energy balance on experimentally-induced colitis. World J Gastroenterol 2012; 18:627-36. [PMID: 22363133 PMCID: PMC3281219 DOI: 10.3748/wjg.v18.i7.627] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 04/09/2011] [Accepted: 04/16/2011] [Indexed: 02/06/2023] Open
Abstract
AIM: To characterize the influence of diet-induced changes in body fat on colitis severity in SMAD3-/- mice.
METHODS: SMAD3-/- mice (6-8 wk of age) were randomly assigned to receive a calorie restricted (30% of control; CR), control (CON), or high fat (HF) diet for 20 wk and were gavaged with sterile broth or with Helicobacter hepaticus (H. hepaticus) to induce colitis. Four weeks after infection, mice were sacrificed and the cecum and colons were processed for histological evaluation.
RESULTS: Dietary treatment significantly influenced body composition prior to infection (P < 0.05), with CR mice having less (14% ± 2%) and HF-fed mice more body fat (32% ± 7%) compared to controls (22% ± 4%). Differences in body composition were associated with alterations in plasma levels of leptin (HF > CON > CR) and adiponectin (CON > HF ≥ CR) (P < 0.05). There were no significant differences in colitis scores between CON and HF-fed mice 4 wk post-infection. Consistent with this, differences in proliferation and inflammation markers (COX-2, iNOS), and infiltrating cell types (CD3+ T lymphocytes, macrophages) were not observed. Unexpectedly, only 40% of CR mice survived infection with H. hepaticus, with mortality observed as early as 1 wk following induction of colitis.
CONCLUSION: Increased adiposity does not influence colitis severity in SMAD3-/- mice. Importantly, caloric restriction negatively impacts survival following pathogen challenge, potentially due to an impaired immune response.
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244
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Selection of non-competitive leptin antagonists using a random nanobody-based approach. Biochem J 2012; 441:425-34. [PMID: 21851341 DOI: 10.1042/bj20110438] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The adipocyte-derived cytokine leptin acts as a metabolic switch, connecting the body's metabolism to high-energy consuming processes such as reproduction and immune responses. Accumulating evidence suggests that leptin plays a role in human pathologies, such as autoimmune diseases and cancer, thus providing a rationale for the development of leptin antagonists. In the present study, we generated and evaluated a panel of neutralizing nanobodies targeting the LR (leptin receptor). A nanobody comprises the variable domain of the naturally occurring single-chain antibodies found in members of the Camelidae family. We identified three classes of neutralizing nanobodies targeting different LR subdomains: i.e. the CRH2 (cytokine receptor homology 2), Ig-like and FNIII (fibronectin type III) domains. Only nanobodies directed against the CRH2 domain inhibited leptin binding. We could show that a nanobody that targets the Ig-like domain potently interfered with leptin-dependent regulation of hypothalamic NPY (neuropeptide Y) expression. As a consequence, daily intraperitoneal injection increased body weight, body fat content, food intake, liver size and serum insulin levels. All of these characteristics resemble the phenotype of leptin and LR-deficient animals. The results of the present study support proposed models of the activated LR complex, and demonstrate that it is possible to block LR signalling without affecting ligand binding. These nanobodies form new tools to study the mechanisms of BBB (blood-brain barrier) leptin transport and the effect of LR inhibition in disease models.
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245
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Abrams ET, Miller EM. The roles of the immune system in women's reproduction: evolutionary constraints and life history trade-offs. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2012; 146 Suppl 53:134-54. [PMID: 22101690 DOI: 10.1002/ajpa.21621] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Life history theory posits that, as long as survival is assured, finite resources are available for reproduction, maintenance, and growth/storage. To maximize lifetime reproductive success, resources are subject to trade-offs both within individuals and between current and future investment. For women, reproducing is costly and time-consuming; the bulk of available resources must be allocated to reproduction at the expense of more flexible systems like immune function. When reproducing women contract infectious diseases, the resources required for immune activation can fundamentally shift the patterns of resource allocation. Adding to the complexity of the reproductive-immune trade-offs in women are the pleiotropic effects of many immune factors, which were modified to serve key roles in mammalian reproduction. In this review, we explore the complex intersections between immune function and female reproduction to situate proximate immunological processes within a life history framework. After a brief overview of the immune system, we discuss some important physiological roles of immune factors in women's reproduction and the conflicts that may arise when these factors must play dual roles. We then discuss the influence of reproductive-immune trade-offs on the patterning of lifetime reproductive success: (1) the effect of immune activation/infectious disease on the timing of life history events; (2) the role of the immune system, immune activation, and infectious disease on resource allocation within individual reproductive events, particularly pregnancy; and (3) the role of the immune system in shaping the offspring's patterns of future life history trade-offs. We close with a discussion of future directions in reproductive immunology for anthropologists.
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Affiliation(s)
- Elizabeth T Abrams
- Department of Anthropology, University of Illinois at Chicago, Chicago, IL 60607, USA.
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246
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Dietary strawberry powder reduces blood glucose concentrations in obese and lean C57BL/6 mice, and selectively lowers plasma C-reactive protein in lean mice. Br J Nutr 2012; 108:1789-99. [PMID: 22293281 DOI: 10.1017/s0007114512000037] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The purpose of the present study was to test the anti-inflammatory and blood glucose (BG)-regulating capacity of strawberries in a mouse model of diet-induced obesity. A total of thirty-six male C57BL/6J mice were randomly divided into four groups (nine mice per group). Mice were fed a low-fat diet (LF, 13 % fat), the LF supplemented with 2·6 % freeze-dried strawberry powder (LFSB), a high-fat diet (HF, 44 % fat) or the HF supplemented with 2·6 % strawberry powder (HFSB). Blood samples were collected to measure BG, inflammation and systemic markers for endocrine function of pancreas and adipose tissue. Splenocytes were harvested at the end of the study and activated with either anti-cluster of differentiation (CD) 3/anti-CD28 antibodies or lipopolysaccharide to test immune responsiveness. The HF increased non-fasted BG, insulin, soluble intracellular adhesion molecule-1, E-selectin, leptin, resistin and plasminogen activator protein-1 (P < 0·05). High dietary fat decreased IL-4 production from activated splenocytes (P < 0·05). BG concentrations were lower in the mice supplemented with SB (10·64 mmol/l) compared to the non-supplemented mice (11·37 mmol/l; P = 0·0022). BG values were approximately 6·5 % lower in the supplemented mice. Additionally, SB lowered plasma C-reactive protein in the LFSB group compared to the other three groups (P < 0·05). The dietary intake of SB approximated one human serving of strawberries. These results, although modest, support a promising role for dietary strawberries in reducing the risks associated with obesity and diabetes, and regulating the levels of inflammatory markers in non-obese individuals.
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247
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Ablamunits V, Klebanov S, Giese SY, Herold KC. Functional human to mouse adipose tissue xenotransplantation. J Endocrinol 2012; 212:41-7. [PMID: 22007021 DOI: 10.1530/joe-11-0201] [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: 11/08/2022]
Abstract
White adipose tissue (WAT) produces a number of metabolically important factors and, therefore, some inborn errors of metabolism may potentially be corrected by transplantation of normal allogeneic WAT. To explore the ability of human WAT (HuWAT) to compensate for a missing factor and to induce allogeneic immune response, we created leptin-deficient, immunodeficient mice and transplanted them with either 2·5 or 5 ml HuWAT. Recipient mice showed stable levels of human leptin in circulation, reduced body mass gain, and amelioration of hepatic steatosis. Food consumption and plasma insulin levels were reduced only in recipients of 5 ml WAT. Transfer of 2×10(7) human mononuclear cells to reject WAT as an allograft was ineffective and resulted only in some reduction of circulating leptin and a limited damage to the WAT grafts followed by the loss of human leukocytes.
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Affiliation(s)
- Vitaly Ablamunits
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA.
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248
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Ben-Shlomo S, Einstein FH, Zvibel I, Atias D, Shlomai A, Halpern Z, Barzilai N, Fishman S. Perinephric and epididymal fat affect hepatic metabolism in rats. Obesity (Silver Spring) 2012; 20:151-6. [PMID: 21818154 DOI: 10.1038/oby.2011.261] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The present study examined whether the perinephric and epididymal visceral fat (PEVF) depot under short-term excess nutrient protected the liver by trapping nutrient-derived nonesterified free fatty acids (NEFAs) or had deleterious effects on hepatic triglycerides (TGs) accumulation and insulin resistance due to adipokine secretion. Young rats pre-emptively underwent surgical PEVF removal or sham operations and were fed with either high-fat diet (HFD) (PEVF-HFD) or regular chow (RC) (PEVF-RC) for 3 days. Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp. Liver TG, serum NEFA, and fat-derived adipokines were assessed. Insulin and lipogenesis signaling were assessed by western blots. Pre-emptive PEVF removal significantly decreases insulin-induced suppression of hepatic glucose production (HGP) both in RC and in HFD-fed rats. In accordance with the clamp results, hepatic TG accumulation is also significantly reduced by PEVF excision both in RC and HFD-fed rats. These results are further validated by insulin signaling results, which show that pre-emptive PEVF removal increases phosphorylation of hepatic Akt, irrespective of diet. Notably, high levels of serum leptin induced by HFD are significantly reduced by pre-emptive PEVF excision. Additionally, expression of lipogenic enzyme p-acetyl-CoA-carboxylase, denoting reduced lipogenesis, is increased in the PEVF-HFD rats. In conclusion, PEVF has a deleterious effect on the liver as a source of insulin resistance-inducing adipokines irrespective of diet, and does not serve as a buffer for excess nutrients.
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Affiliation(s)
- Shani Ben-Shlomo
- The Research Center for Digestive Tract and Liver Diseases, Tel-Aviv Sourasky Medical Center and the Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
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249
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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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Trellakis S, Rydleuskaya A, Fischer C, Canbay A, Tagay S, Scherag A, Bruderek K, Schuler PJ, Brandau S. Low adiponectin, high levels of apoptosis and increased peripheral blood neutrophil activity in healthy obese subjects. Obes Facts 2012; 5:305-18. [PMID: 22722748 DOI: 10.1159/000339452] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 11/15/2011] [Indexed: 01/23/2023] Open
Abstract
OBJECTIVE Growing evidence supports a link between obesity and inflammation. Current research is focused on the role of adipokines such as adiponectin and immune cells, especially macrophages, in adipose tissue. Our aim was to examine the role of inflammation not in tissue but in the peripheral blood of healthy overweight and obese subjects. We especially investigated the role of neutrophils and their possible regulation by adiponectin. METHODS In healthy normal-weight, overweight, and obese human subjects (n = 32) the peripheral blood concentrations of adipokines, satiety hormones, apoptosis markers, and cytokines as well as the blood count were related to inflammation and neutrophils, at 3 independent days of examination. The response of neutrophils to stimulation by adiponectin was also investigated in vitro. RESULTS In obese and by tendency already in overweight subjects, inflammation was increased showing a higher neutrophil-to-lymphocyte ratio, elevated high-sensitivity C-reactive protein, increased chemokines (CXCL8, CCL3, CCL5), increased apoptosis markers (M30 and M65), and changes in hormone levels in the peripheral blood. LPS- and fMLP-induced production of CXCL8 by neutrophils was elevated in overweight and obese subjects. High plasma levels of adiponectin were associated with reduced CXCL8 production in peripheral blood neutrophils. In vitro, production of CXCL8 by neutrophils was inhibited by adiponectin. CONCLUSION Reduced adiponectin and enhanced apoptosis may occur already in the peripheral blood of healthy overweight subjects. This process seems to further enhance neutrophil activity in overweight and obese.
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Affiliation(s)
- Sokratis Trellakis
- Department of Otorhinolaryngology, Biometry and Epidemiology, University Hospital Essen, Essen, Germany.
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