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Vasamsetti SB, Natarajan N, Sadaf S, Florentin J, Dutta P. Regulation of cardiovascular health and disease by visceral adipose tissue-derived metabolic hormones. J Physiol 2023; 601:2099-2120. [PMID: 35661362 PMCID: PMC9722993 DOI: 10.1113/jp282728] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 05/04/2022] [Indexed: 11/08/2022] Open
Abstract
Visceral adipose tissue (VAT) is a metabolic organ known to regulate fat mass, and glucose and nutrient homeostasis. VAT is an active endocrine gland that synthesizes and secretes numerous bioactive mediators called 'adipocytokines/adipokines' into systemic circulation. These adipocytokines act on organs of metabolic importance like the liver and skeletal muscle. Multiple preclinical and in vitro studies showed strong evidence of the roles of adipocytokines in the regulation of metabolic disorders like diabetes, obesity and insulin resistance. Adipocytokines, such as adiponectin and omentin, are anti-inflammatory and have been shown to prevent atherogenesis by increasing nitric oxide (NO) production by the endothelium, suppressing endothelium-derived inflammation and decreasing foam cell formation. By inhibiting differentiation of vascular smooth muscle cells (VSMC) into osteoblasts, adiponectin and omentin prevent vascular calcification. On the other hand, adipocytokines like leptin and resistin induce inflammation and endothelial dysfunction that leads to vasoconstriction. By promoting VSMC migration and proliferation, extracellular matrix degradation and inflammatory polarization of macrophages, leptin and resistin increase the risk of atherosclerotic plaque vulnerability and rupture. Additionally, the plasma concentrations of these adipocytokines alter in ageing, rendering older humans vulnerable to cardiovascular disease. The disturbances in the normal physiological concentrations of these adipocytokines secreted by VAT under pathological conditions impede the normal functions of various organs and affect cardiovascular health. These adipokines could be used for both diagnostic and therapeutic purposes in cardiovascular disease.
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Affiliation(s)
- Sathish Babu Vasamsetti
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA 15213
- Pittsburgh VA Medical Center-University Drive, University Drive C, Pittsburgh, PA, USA
| | - Niranjana Natarajan
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA 15213
| | - Samreen Sadaf
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA 15213
- Pittsburgh VA Medical Center-University Drive, University Drive C, Pittsburgh, PA, USA
| | - Jonathan Florentin
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA 15213
| | - Partha Dutta
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA 15213
- Pittsburgh VA Medical Center-University Drive, University Drive C, Pittsburgh, PA, USA
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA, 15213
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA, 15213
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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Liu J, Lai F, Hou Y, Zheng R. Leptin signaling and leptin resistance. MEDICAL REVIEW (BERLIN, GERMANY) 2022; 2:363-384. [PMID: 37724323 PMCID: PMC10388810 DOI: 10.1515/mr-2022-0017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 07/12/2022] [Indexed: 09/20/2023]
Abstract
With the prevalence of obesity and associated comorbidities, studies aimed at revealing mechanisms that regulate energy homeostasis have gained increasing interest. In 1994, the cloning of leptin was a milestone in metabolic research. As an adipocytokine, leptin governs food intake and energy homeostasis through leptin receptors (LepR) in the brain. The failure of increased leptin levels to suppress feeding and elevate energy expenditure is referred to as leptin resistance, which encompasses complex pathophysiological processes. Within the brain, LepR-expressing neurons are distributed in hypothalamus and other brain areas, and each population of the LepR-expressing neurons may mediate particular aspects of leptin effects. In LepR-expressing neurons, the binding of leptin to LepR initiates multiple signaling cascades including janus kinase (JAK)-signal transducers and activators of transcription (STAT) phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT), extracellular regulated protein kinase (ERK), and AMP-activated protein kinase (AMPK) signaling, etc., mediating leptin actions. These findings place leptin at the intersection of metabolic and neuroendocrine regulations, and render leptin a key target for treating obesity and associated comorbidities. This review highlights the main discoveries that shaped the field of leptin for better understanding of the mechanism governing metabolic homeostasis, and guides the development of safe and effective interventions to treat obesity and associated diseases.
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Affiliation(s)
- Jiarui Liu
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Health Science Center, Peking University, Beijing, China
| | - Futing Lai
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Health Science Center, Peking University, Beijing, China
| | - Yujia Hou
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Health Science Center, Peking University, Beijing, China
| | - Ruimao Zheng
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Health Science Center, Peking University, Beijing, China
- Neuroscience Research Institute, Peking University, Beijing, China
- Key Laboratory for Neuroscience of Ministry of Education, Peking University, Beijing, China
- Key Laboratory for Neuroscience of National Health Commission, Peking University, Beijing 100191, China
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3
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Misch M, Puthanveetil P. The Head-to-Toe Hormone: Leptin as an Extensive Modulator of Physiologic Systems. Int J Mol Sci 2022; 23:ijms23105439. [PMID: 35628271 PMCID: PMC9141226 DOI: 10.3390/ijms23105439] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/30/2022] [Accepted: 05/10/2022] [Indexed: 12/12/2022] Open
Abstract
Leptin is a well-known hunger-sensing peptide hormone. The role of leptin in weight gain and metabolic homeostasis has been explored for the past two decades. In this review, we have tried to shed light upon the impact of leptin signaling on health and diseases. At low or moderate levels, this peptide hormone supports physiological roles, but at chronically higher doses exhibits detrimental effects on various systems. The untoward effects we observe with chronically higher levels of leptin are due to their receptor-mediated effect or due to leptin resistance and are not well studied. This review will help us in understanding the non-anorexic roles of leptin, including their contribution to the metabolism of various systems and inflammation. We will be able to get an alternative perspective regarding the physiological and pathological roles of this mysterious peptide hormone.
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Affiliation(s)
- Monica Misch
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA;
| | - Prasanth Puthanveetil
- Department of Pharmacology, College of Graduate Studies, Midwestern University, Downers Grove, IL 60515, USA
- Correspondence: ; Tel.: +1-630-960-3935
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Varma B, Ogunmoroti O, Ndumele CE, Zhao D, Szklo M, Sweeney T, Allison MA, Budoff MJ, Subramanya V, Bertoni AG, Michos ED. Higher Leptin Levels Are Associated with Coronary Artery Calcium Progression: the Multi-Ethnic Study of Atherosclerosis (MESA). DIABETES EPIDEMIOLOGY AND MANAGEMENT 2022; 6:100047. [PMID: 35132401 PMCID: PMC8817736 DOI: 10.1016/j.deman.2021.100047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Adipokines play a role in cardiometabolic pathways. Coronary artery calcium (CAC) progression prognosticates cardiovascular disease (CVD) risk. However, the association of adipokines with CAC progression is not well established. We examined the association of adipokines with CAC progression in a multi-ethnic cohort free of CVD at baseline. METHODS We included 1,904 randomly-selected adults enrolled in the Multi-Ethnic Study of Atherosclerosis who had both adipokine levels [leptin, resistin, adiponectin] and CAC by CT measured at either exam 2 (2002-2004) or exam 3 (2004-2005). CAC was previously measured at exam 1 (2000-2002) and a subset (n=566) had CAC measured at exam 5 (2010-2012). We used logistic regression to examine odds of CAC progression between exam 1 and 2/3 (defined as >0 Agatston units of change/year). We used linear mixed effect models to examine CAC progression from exam 2/3 to 5. RESULTS At exam 2/3, the mean age was 65(10) yrs; 50% women. In models adjusted for sociodemographic factors and BMI, the highest tertile of leptin, compared to lowest, was associated with an increased odds of CAC progression over the preceding 2.6yrs [OR 1.60 (95% CI: 1.10-2.33)]. In models further adjusted for visceral fat and CVD risk factors, the highest tertile of leptin was statistically significantly associated with a 4% (1-7%) greater CAC progression over an average of 7yrs. No associations were seen for resistin and adiponectin. CONCLUSIONS Higher leptin levels were independently, but modestly, associated with CAC progression. Atherosclerosis progression may be one mechanism through which leptin confers increased CVD risk.
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Affiliation(s)
- Bhavya Varma
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Oluseye Ogunmoroti
- Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Chiadi E. Ndumele
- Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Di Zhao
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Moyses Szklo
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Ty Sweeney
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Matthew A. Allison
- Department of Family Medicine, University of California San Diego, San Diego, CA
| | | | - Vinita Subramanya
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA
| | - Alain G. Bertoni
- Department of Epidemiology & Prevention, Wake Forest School of Medicine, Winston Salem, NC
| | - Erin D. Michos
- Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
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5
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Balatskiy A, Ozhimalov I, Balatskaya M, Savina A, Filatova J, Kalinina N, Popov V, Tkachuk V. Immature Vascular Smooth Muscle Cells in Healthy Murine Arteries and Atherosclerotic Plaques: Localization and Activity. Int J Mol Sci 2022; 23:1744. [PMID: 35163667 PMCID: PMC8835789 DOI: 10.3390/ijms23031744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 02/01/2022] [Accepted: 02/01/2022] [Indexed: 01/27/2023] Open
Abstract
The local development of atherosclerotic lesions may, at least partly, be associated with the specific cellular composition of atherosclerosis-prone regions. Previously, it was demonstrated that a small population of immature vascular smooth muscle cells (VSMCs) expressing both CD146 and neuron-glial antigen 2 is postnatally sustained in atherosclerosis-prone sites. We supposed that these cells may be involved in atherogenesis and can continuously respond to angiotensin II, which is an atherogenic factor. Using immunohistochemistry, flow cytometry, wound migration assay xCELLigence system, and calcium imaging, we studied the functional activities of immature VSMCs in vitro and in vivo. According to our data, these cells do not express nestin, CD105, and the leptin receptor. They are localized in atherosclerosis-prone regions, and their number increases with age, from 5.7% to 23%. Immature VSMCs do not migrate to low shear stress areas and atherosclerotic lesions. They also do not have any unique response to angiotensin II. Thus, despite the localization of immature VSMCs and the presence of the link between their number and age, our study did not support the hypothesis that immature VSMCs are directly involved in the formation of atherosclerotic lesions. Additional lineage tracing studies can clarify the fate of these cells during atherogenesis.
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MESH Headings
- Aging/pathology
- Angiotensin II
- Animals
- Aorta, Thoracic/pathology
- Arteries/pathology
- Carotid Artery, Common/pathology
- Cell Movement
- Cell Proliferation
- Cells, Cultured
- Immunophenotyping
- Mice, Inbred C57BL
- Mice, Knockout
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/pathology
- Plaque, Atherosclerotic/pathology
- Receptor, Angiotensin, Type 2/metabolism
- Shear Strength
- Stress, Mechanical
- Mice
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Affiliation(s)
- Alexander Balatskiy
- Medical Scientific and Educational Centre, Lomonosov Moscow State University, 119192 Moscow, Russia;
- Institute of Basic Neurology, Federal Center of Brain Research and Neurotechnologies, Federal Biomedical Agency, 117513 Moscow, Russia
| | - Ilia Ozhimalov
- Faculty of Medicine, Lomonosov Moscow State University, 119991 Moscow, Russia; (I.O.); (M.B.); (A.S.); (N.K.); (V.P.)
| | - Maria Balatskaya
- Faculty of Medicine, Lomonosov Moscow State University, 119991 Moscow, Russia; (I.O.); (M.B.); (A.S.); (N.K.); (V.P.)
| | - Alexandra Savina
- Faculty of Medicine, Lomonosov Moscow State University, 119991 Moscow, Russia; (I.O.); (M.B.); (A.S.); (N.K.); (V.P.)
| | - Julia Filatova
- Department of Cardiology, A.I. Yevdokimov Moscow State University of Medicine and Dentistry, Ministry of Healthcare, 127473 Moscow, Russia;
| | - Natalia Kalinina
- Faculty of Medicine, Lomonosov Moscow State University, 119991 Moscow, Russia; (I.O.); (M.B.); (A.S.); (N.K.); (V.P.)
| | - Vladimir Popov
- Faculty of Medicine, Lomonosov Moscow State University, 119991 Moscow, Russia; (I.O.); (M.B.); (A.S.); (N.K.); (V.P.)
| | - Vsevolod Tkachuk
- Medical Scientific and Educational Centre, Lomonosov Moscow State University, 119192 Moscow, Russia;
- Faculty of Medicine, Lomonosov Moscow State University, 119991 Moscow, Russia; (I.O.); (M.B.); (A.S.); (N.K.); (V.P.)
- Institute of Experimental Cardiology, National Medical Research Center of Cardiology, 121552 Moscow, Russia
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6
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Leptin in Atherosclerosis: Focus on Macrophages, Endothelial and Smooth Muscle Cells. Int J Mol Sci 2021; 22:ijms22115446. [PMID: 34064112 PMCID: PMC8196747 DOI: 10.3390/ijms22115446] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/11/2021] [Accepted: 05/17/2021] [Indexed: 02/06/2023] Open
Abstract
Increasing adipose tissue mass in obesity directly correlates with elevated circulating leptin levels. Leptin is an adipokine known to play a role in numerous biological processes including regulation of energy homeostasis, inflammation, vascular function and angiogenesis. While physiological concentrations of leptin may exhibit multiple beneficial effects, chronically elevated pathophysiological levels or hyperleptinemia, characteristic of obesity and diabetes, is a major risk factor for development of atherosclerosis. Hyperleptinemia results in a state of selective leptin resistance such that while beneficial metabolic effects of leptin are dampened, deleterious vascular effects of leptin are conserved attributing to vascular dysfunction. Leptin exerts potent proatherogenic effects on multiple vascular cell types including macrophages, endothelial cells and smooth muscle cells; these effects are mediated via an interaction of leptin with the long form of leptin receptor, abundantly expressed in atherosclerotic plaques. This review provides a summary of recent in vivo and in vitro studies that highlight a role of leptin in the pathogenesis of atherosclerotic complications associated with obesity and diabetes.
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7
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Ganguly R, Khanal S, Mathias A, Gupta S, Lallo J, Sahu S, Ohanyan V, Patel A, Storm K, Datta S, Raman P. TSP-1 (Thrombospondin-1) Deficiency Protects ApoE -/- Mice Against Leptin-Induced Atherosclerosis. Arterioscler Thromb Vasc Biol 2021; 41:e112-e127. [PMID: 33327743 PMCID: PMC8105272 DOI: 10.1161/atvbaha.120.314962] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Hyperleptinemia, hallmark of obesity, is a putative pathophysiologic trigger for atherosclerosis. We previously reported a stimulatory effect of leptin on TSP-1 (thrombospondin-1) expression, a proatherogenic matricellular protein implicated in atherogenesis. However, a causal role of TSP-1 in leptin-driven atherosclerosis remains unknown. Approach and Results: Seventeen-weeks-old ApoE-/- and TSP-1-/-/ApoE-/- double knockout mice, on normocholesterolemic diet, were treated with or without murine recombinant leptin (5 µg/g bwt, IP) once daily for 3 weeks. Using aortic root morphometry and en face lesion assay, we found that TSP-1 deletion abrogated leptin-stimulated lipid-filled lesion burden, plaque area, and collagen accumulation in aortic roots of ApoE-/- mice, shown via Oil red O, hematoxylin and eosin, and Masson trichrome staining, respectively. Immunofluorescence microscopy of aortic roots showed that TSP-1 deficiency blocked leptin-induced inflammatory and smooth muscle cell abundance as well as cellular proliferation in ApoE-/- mice. Moreover, these effects were concomitant to changes in VLDL (very low-density lipoprotein)-triglyceride and HDL (high-density lipoprotein)-cholesterol levels. Immunoblotting further revealed reduced vimentin and pCREB (phospho-cyclic AMP response element-binding protein) accompanied with augmented smooth muscle-myosin heavy chain expression in aortic vessels of leptin-treated double knockout versus leptin-treated ApoE-/-; also confirmed in aortic smooth muscle cells from the mice genotypes, incubated ± leptin in vitro. Finally, TSP-1 deletion impeded plaque burden in leptin-treated ApoE-/- on western diet, independent of plasma lipid alterations. CONCLUSIONS The present study provides evidence for a protective effect of TSP-1 deletion on leptin-stimulated atherogenesis. Our findings suggest a regulatory role of TSP-1 on leptin-induced vascular smooth muscle cell phenotypic transition and inflammatory lesion invasion. Collectively, these results underscore TSP-1 as a potential target of leptin-induced vasculopathy.
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MESH Headings
- Animals
- Aorta/metabolism
- Aorta/pathology
- Aortic Diseases/chemically induced
- Aortic Diseases/metabolism
- Aortic Diseases/pathology
- Aortic Diseases/prevention & control
- Atherosclerosis/chemically induced
- Atherosclerosis/metabolism
- Atherosclerosis/pathology
- Atherosclerosis/prevention & control
- Cell Differentiation
- Cell Proliferation
- Cells, Cultured
- Collagen/metabolism
- Diet, High-Fat
- Disease Models, Animal
- Leptin
- Male
- Mice, Inbred C57BL
- Mice, Knockout, ApoE
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Plaque, Atherosclerotic
- Signal Transduction
- Thrombospondin 1/deficiency
- Thrombospondin 1/genetics
- Mice
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Affiliation(s)
- Rituparna Ganguly
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH
- School of Biomedical Sciences, Kent State University, Kent, OH
- Current Address: Department of Diabetes Complications and Metabolism, City of Hope, 1500 East Duarte Road, Duarte, CA 91010
| | - Saugat Khanal
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH
- School of Biomedical Sciences, Kent State University, Kent, OH
| | - Amy Mathias
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH
| | - Shreya Gupta
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH
- School of Biomedical Sciences, Kent State University, Kent, OH
| | - Jason Lallo
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH
| | - Soumyadip Sahu
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH
- School of Biomedical Sciences, Kent State University, Kent, OH
- Current Address: National Institute of Environmental Health Sciences, Research Triangle Park, Durham, NC 27709
| | - Vahagn Ohanyan
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH
- School of Biomedical Sciences, Kent State University, Kent, OH
| | - Aakaash Patel
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH
| | - Kyle Storm
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH
| | - Sujay Datta
- Department of Statistics, The University of Akron, Akron, OH
| | - Priya Raman
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH
- School of Biomedical Sciences, Kent State University, Kent, OH
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Can ME, Kızıltoprak H, Buluş AD, Özkoyuncu D, Koç M, Özdemir Yıldız Z. Corneal Biomechanical Properties in Childhood Obesity. J Pediatr Ophthalmol Strabismus 2020; 57:103-107. [PMID: 32203594 DOI: 10.3928/01913913-20200131-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 12/30/2019] [Indexed: 11/20/2022]
Abstract
PURPOSE To investigate corneal biomechanical properties in patients with childhood obesity. METHODS The study included 47 patients with childhood obesity (study group) and 39 healthy patients (control group). Corneal hysteresis, corneal resistance factor, corneal compensated intraocular pressure (IOPcc), and Goldmann-correlated IOP (IOPg) were measured with the Ocular Response Analyzer (Reichert, Ophthalmic Instruments, Buffalo, NY) in each eye. Central corneal thickness (CCT), anterior chamber angle (ACA), anterior chamber volume (ACV), and anterior chamber depth (ACD) measurements were obtained by the Pentacam rotating Scheimpflug camera (Oculus Optikgeräte GmBh, Wetzlar, Germany). RESULTS The mean corneal hysteresis was 10.56 ± 1.52 mm Hg in the study group and 11.16 ± 1.92 mm Hg in the control group (P = .022). The mean IOP was 14.9 ± 2.0 mm Hg in the study group and 14.1 ± 1.3 mm Hg in the control group (P = .003). Corneal hysteresis showed a significant, positive correlation with corneal resistance factor (P < .001, r = 0.851), IOPg (P = .044, r = 0.213), CCT (P < .001, r = 0.477), and IOP (P = .005, r = 0.295). Corneal hysteresis showed a significant, negative correlation with IOPcc (P = .001, r = -0.355), ACA (P = .005, r = -0.294), ACV (P = .019, r = -0.246), and ACD (P = .046, r = -0.211). CONCLUSIONS Patients with childhood obesity have lower corneal hysteresis and higher IOPcc measurements when compared with healthy patients. Corneal tissue changes may occur in early life in childhood obesity, which could lead to ocular disease in the future. [J Pediatr Ophthalmol Strabismus. 2020;57(2):103-107.].
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9
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Liu R, Chen B, Chen J, Lan J. Leptin upregulates smooth muscle cell expression of MMP-9 to promote plaque destabilization by activating AP-1 via the leptin receptor/MAPK/ERK signaling pathways. Exp Ther Med 2018; 16:5327-5333. [PMID: 30542491 DOI: 10.3892/etm.2018.6853] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 07/02/2018] [Indexed: 01/17/2023] Open
Abstract
Leptin has been reported to be expressed in carotid atherosclerotic plaques, where it can promote lesion instability. Matrix metalloproteinases (MMPs) produced by smooth muscle cells (SMCs) are known to contribute to the weakening of atherosclerotic plaques via the degradation of extracellular matrix (ECM) proteins. The present study investigated whether leptin promotes plaque rupture by increasing the expression of MMP in SMCs in vivo and in vitro. In vivo, the neointima/media ratio and expression of MMP in the carotid artery of ob/ob mice were measured following carotid ligation and systemic administration of leptin. In vitro, the effect of leptin treatment on the expression of MMP in isolated SMCs and the underlying signaling pathways were investigated by gelatin zymography and western blot analysis. The results demonstrated that leptin treatment significantly increased the neointima/media ratio and expression of MMP-9 in the carotid artery of mice following carotid ligation. In vitro, leptin also significantly increased the expression and activity of MMP-9 in cultured SMCs in a dose-dependent manner. Leptin also increased the production of MMP-9 by activating leptin receptor and mitogen-activated protein kinases, including extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), which in turn enhanced the binding of the transcription factor activator protein-1 (AP-1) to the MMP-9 promoter. The inhibition of leptin-activated phosphorylation of ERK and JNK suppressed the leptin-stimulated expression of AP-1 and MMP-9. Leptin treatment induced the expression of MMP-9 in SMCs, suggesting that leptin may have substantial involvement in plaque rupture by promoting the degradation of ECM.
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Affiliation(s)
- Ruijie Liu
- Department of Cardiology, Dongguan Third People's Hospital, Dongguan, Guangdong 523326, P.R. China
| | - Benfa Chen
- Department of Cardiology, Donghua Hospital of Sun Yat-sen University, Dongguan, Guangdong 523326, P.R. China
| | - Jiemin Chen
- Department of Cardiology, Dongguan Third People's Hospital, Dongguan, Guangdong 523326, P.R. China
| | - Jun Lan
- Department of Cardiology, Dongguan Third People's Hospital, Dongguan, Guangdong 523326, P.R. China
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10
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Abstract
Leptin is an adipocyte-derived hormone, which contributes to the homeostatic regulation of energy balance and metabolism through humoral and neural pathways. Leptin acts on the neurons in certain brain areas such as the hypothalamus, hippocampus, and brain stem to regulate food intake, thermogenesis, energy expenditure, and homeostasis of glucose/lipid metabolism. The pathologically increased circulating leptin is a biomarker of leptin resistance, which is common in obese individuals. Leptin resistance is defined by a reduced sensitivity or a failure in response of the brain to leptin, showing a decrease in the ability of leptin to suppress appetite or enhance energy expenditure, which causes an increased food intake and finally leads to overweight, obesity, cardiovascular diseases, and other metabolic disorders. Leptin resistance is a challenge for clinical treatment or drug discovery of obesity. Until recently, emerging evidence has been showing novel mechanisms of the leptin resistance. Here, we summarized the advances and controversy of leptin resistance and associated diseases, for better understanding the physiology and pathophysiology of leptin as well as the new strategies for treating obesity and metabolic disorders.
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11
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Shoeibi S, Mozdziak P, Mohammadi S. Important signals regulating coronary artery angiogenesis. Microvasc Res 2017; 117:1-9. [PMID: 29247718 DOI: 10.1016/j.mvr.2017.12.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Revised: 12/07/2017] [Accepted: 12/08/2017] [Indexed: 01/03/2023]
Abstract
Angiogenesis is a complex process of budding, the formation of new blood vessels from pre-existing microvessels, via migration, proliferation and survival. Vascular angiogenesis factors include different classes of molecules that have a fundamental role in blood vessel formation. Numerous inducers of angiogenesis, such as the members of the vascular endothelial growth factor (VEGF) family, basic fibroblast growth factor (bFGF), angiopoietin (Ang), hepatocyte growth factor (HGF), and hypoxia inducible factor-1 (HIF-1), have an important role in angiogenesis. However, VEGF, platelet-derived growth factor (PDGF), and transforming growth factor β (TGF-β) expression appear to be important in intraplaque angiogenesis. Interaction and combined effects between growth factors is essential in endothelial cell migration, proliferation, differentiation, and endothelial cell-cell communication that ultimately lead to the microvessel formation. Since VEGF has a key role during angiogenesis; it may be considered as a good therapeutic target in the clinic. The essential function of several angiogenic factors involved in coronary angiogenesis and intraplaque angiogenesis in atherosclerosis are carefully considered along with the use of angiogenic factors in clinical practice.
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Affiliation(s)
- Sara Shoeibi
- Cellular and Molecular research Center, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
| | - Paul Mozdziak
- Graduate Physiology Program, North Carolina State University, Raleigh, NC
| | - Shabnam Mohammadi
- Department of Basic Sciences, Faculty of Medicine, Gonabad University of Medical Sciences, Gonabad, Iran
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Alfer J, Happel L, Dittrich R, Beckmann MW, Hartmann A, Gaumann A, Buck VU, Classen-Linke I. Insufficient Angiogenesis: Cause of Abnormally Thin Endometrium in Subfertile Patients? Geburtshilfe Frauenheilkd 2017; 77:756-764. [PMID: 28729745 DOI: 10.1055/s-0043-111899] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 05/21/2017] [Accepted: 05/22/2017] [Indexed: 12/14/2022] Open
Abstract
INTRODUCTION This study investigated subfertile patients with abnormally thin endometrium after infertility treatment. As they had adequate serum concentrations of hormones, an endometrial factor for subfertility was suspected. METHODS To elucidate the cause of subfertility, endometrial biopsies were taken in each patient in the late proliferative and mid-secretory phases of one menstrual cycle. Endometrial biopsies from women with normal menstrual cycles and confirmed fertility who were undergoing hysterectomy for benign uterine disease were used as positive controls. The tissue samples were investigated for steroid hormone receptor expression and for the proliferation marker Ki-67. Immunohistochemistry was performed with antibodies against the marker molecules for endometrial receptivity - β 3 integrin, VEGF, LIF, and CD56 (large granular lymphocytes, LGLs). RESULTS The steroid hormone receptors for estrogen (E2) and progesterone (P) were expressed normally (at the first biopsy) and were down-regulated (at the second biopsy) within the cycle. Strikingly, all of the marker molecules investigated showed negative or weak and inadequate expression in the mid-secretory phase. Numbers of LGLs remained as low as in the proliferative phase. In contrast, fertile patients were found to express these marker molecules distinctly in the mid-secretory phase. CONCLUSIONS It may be hypothesized that a severe deficiency of these angiogenesis-related marker molecules leads to defective development of the endometrium, which remains thin. Deficient angiogenetic development may thus provide an explanation for the endometrial factor that causes infertility. Further investigations will need to focus on identifying the regulating factors that act between steroid receptor activation and the expression of these marker molecules.
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Affiliation(s)
- Joachim Alfer
- Institute of Pathology, Kaufbeuren-Ravensburg, Ravensburg, Germany
| | - Lars Happel
- Institute of Reproductive Medicine, IVF-Saar, Saarbrücken, Germany
| | - Ralf Dittrich
- Department of Obstetrics and Gynecology, Erlangen University Hospital Friedrich-Alexander Universität, Erlangen-Nürnberg, Germany
| | - Matthias W Beckmann
- Department of Obstetrics and Gynecology, Erlangen University Hospital Friedrich-Alexander Universität, Erlangen-Nürnberg, Germany
| | - Arndt Hartmann
- Department of Pathology, Erlangen University Hospital Friedrich-Alexander Universität, Erlangen-Nürnberg, Germany
| | - Andreas Gaumann
- Institute of Pathology, Kaufbeuren-Ravensburg, Ravensburg, Germany
| | - Volker U Buck
- Institute of Molecular and Cellular Anatomy, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Irmgard Classen-Linke
- Institute of Molecular and Cellular Anatomy, Medical Faculty, RWTH Aachen University, Aachen, Germany
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Bulus AD, Can ME, Baytaroglu A, Can GD, Cakmak HB, Andiran N. Choroidal Thickness in Childhood Obesity. Ophthalmic Surg Lasers Imaging Retina 2017; 48:10-17. [DOI: 10.3928/23258160-20161219-02] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 10/05/2016] [Indexed: 12/30/2022]
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Sahu S, Ganguly R, Raman P. Leptin augments recruitment of IRF-1 and CREB to thrombospondin-1 gene promoter in vascular smooth muscle cells in vitro. Am J Physiol Cell Physiol 2016; 311:C212-24. [PMID: 27281481 DOI: 10.1152/ajpcell.00068.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 06/02/2016] [Indexed: 01/26/2023]
Abstract
We previously reported that high pathophysiological concentrations of leptin, the adipocyte-secreted peptide, upregulate the expression of a potent proatherogenic matricellular protein, thrombospondin-1 (TSP-1), in vascular smooth muscle cells. Moreover, this regulation was found to occur at the level of transcription; however, the underlying molecular mechanisms remain unknown. The goal of the present study was to investigate the specific transcriptional mechanisms that mediate upregulation of TSP-1 expression by leptin. Primary human aortic smooth muscle cell cultures were transiently transfected with different TSP-1 gene (THBS1) promoter-linked luciferase reporter constructs, and luciferase activity in response to leptin (100 ng/ml) was assessed. We identified a long THBS1 promoter (-1270/+750) fragment with specific leptin response elements that are required for increased TSP-1 transcription by leptin. Promoter analyses, protein/DNA array and gel shift assays demonstrated activation and association of transcription factors, interferon regulatory factor-1 (IRF-1) and cAMP response element-binding protein (CREB), to the distal fragment of the THBS1 promoter in response to leptin. Supershift, chromatin immunoprecipitation, and coimmunoprecipitation assays revealed formation of a single complex between IRF-1 and CREB in response to leptin; importantly, recruitment of this complex to the THBS1 promoter mediated leptin-induced TSP-1 transcription. Finally, binding sequence decoy oligomer and site-directed mutagenesis revealed that regulatory elements for both IRF-1 (-1019 to -1016) and CREB (-1198 to -1195), specific to the distal THBS1 promoter, were required for leptin-induced TSP-1 transcription. Taken together, these findings demonstrate that leptin promotes a cooperative association between IRF-1 and CREB on the THBS1 promoter driving TSP-1 transcription in vascular smooth muscle cells.
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Affiliation(s)
- Soumyadip Sahu
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio; and School of Biomedical Sciences, Kent State University, Kent, Ohio
| | - Rituparna Ganguly
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio; and School of Biomedical Sciences, Kent State University, Kent, Ohio
| | - Priya Raman
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio; and School of Biomedical Sciences, Kent State University, Kent, Ohio
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The impacts of obesity on the cardiovascular and renal systems: cascade of events and therapeutic approaches. Curr Hypertens Rep 2016; 17:7. [PMID: 25620635 DOI: 10.1007/s11906-014-0520-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
There is a neglected epidemic of both obesity and metabolic syndrome in industrialized and unindustrialized countries all over the globe. Both conditions are associated with a high incidence of other serious pathologies, such as cardiovascular and renal diseases. In this article, we review the potential underlying mechanisms by which obesity and metabolic syndrome promote hypertension, including changes in cardiovascular-renal physiology induced by leptin, the sympathetic nervous system, the renin-angiotensin-aldosterone system, insulin resistance, free fatty acids, natriuretic peptides, and proinflammatory cytokines. We also discuss the potential underlying mechanisms by which obesity promotes other cardiovascular and renal conditions, as well as available nonpharmacologic and pharmacologic approaches for treating obesity-induced hypertension. The findings presented herein suggest that adipocytes may be a key regulator of cardiovascular and renal function.
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Mohamed HG, Idris SB, Mustafa M, Ahmed MF, Åstrøm AN, Mustafa K, Ibrahim SO. Impact of Chronic Periodontitis on Levels of Glucoregulatory Biomarkers in Gingival Crevicular Fluid of Adults with and without Type 2 Diabetes. PLoS One 2015; 10:e0127660. [PMID: 25993052 PMCID: PMC4438982 DOI: 10.1371/journal.pone.0127660] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 04/17/2015] [Indexed: 12/23/2022] Open
Abstract
The relationship between diabetes and periodontal disease is bidirectional, but information about the effect of chronic periodontitis on the levels of the glucoregulatory biomarkers locally in gingival crevicular fluid (GCF) is limited. The aim of this study was to compare the levels of 10 glucoregulatory biomarkers in GCF, firstly in subjects with type 2 diabetes (T2DM) presenting with and without chronic periodontitis and secondly, in subjects without diabetes, with and without chronic periodontitis. The material comprised a total of 152 subjects, stratified as: 54 with T2DM and chronic periodontitis (G1), 24 with T2DM (G2), 30 with chronic periodontitis (G3) and 44 without T2DM or periodontitis (G4). The levels of the biomarkers were measured using multiplex biometric immunoassays. Periodontal pocket depths were recorded in mm. Subsets G1 and G2 and subsets G3 and G4 were compared independently. Among T2DM subjects, GIP, GLP-1 and glucagon were significantly up-regulated in G1 compared to G2. Moreover, there were no statistical differences between the two groups regarding C-peptide, insulin, ghrelin, leptin and PAI-1. Comparisons among individuals without T2DM revealed significantly lower amounts of C-peptide and ghrelin in G3 than in G4. The number of sites with pocket depth ≥ 4mm correlated negatively with C-peptide (Spearman’s correlation co-efficient: -0.240, P < 0.01) and positively with GIP and visfatin (Spearman’s correlation co-efficient: 0.255 and 0.241, respectively, P < 0.01). The results demonstrate that chronic periodontitis adversely influences the GCF levels of glucoregulatory biomarkers, as it is associated with disturbed levels of biomarkers related to the onset of T2DM and its medical complications.
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Affiliation(s)
- Hasaan G. Mohamed
- Department of Clinical Dentistry, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway
- Department of Oral Rehabilitation, Faculty of Dentistry, University of Khartoum, Khartoum, Sudan
- * E-mail:
| | - Shaza B. Idris
- Department of Clinical Dentistry, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway
| | - Manal Mustafa
- Oral Health Competence Center in Western Norway, Hordaland, Bergen, Norway
| | | | - Anne N. Åstrøm
- Department of Clinical Dentistry, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway
| | - Kamal Mustafa
- Department of Clinical Dentistry, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway
| | - Salah O. Ibrahim
- Department of Clinical Dentistry, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway
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Purwar P, Khan MA, Gupta A, Mahdi AA, Pandey S, Singh B, Dixit J, Rai P. The effects of periodontal therapy on serum and salivary leptin levels in chronic periodontitis patients with normal body mass index. Acta Odontol Scand 2015; 73:633-41. [PMID: 25854413 DOI: 10.3109/00016357.2015.1030768] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
SUMMARY Leptin concentrations are altered in favour of pro health after periodontal therapy. BACKGROUND Leptin, a non-glycosylated peptide hormone, not only maintains fat stores, but is also an integral part of host defense repertoire. Leptin levels have been found to be altered in an array of inflammatory diseases including chronic periodontitis (CP), but the role of non-surgical periodontal therapy (NSPT) in altering the leptin concentrations in saliva and serum of CP patients is yet to be ascertained. The aim of the present study is to quantify leptin levels in CP patients having normal body mass index (BMI) pre-therapy as compared to periodontally healthy controls and to address whether successful NSPT alters leptin concentration in serum and saliva. MATERIALS AND METHODS Twenty-two saliva (modified draining method) and serum samples (by venipuncture) were collected from CP patients with normal BMI (n = 22), before and at 4 and 12 weeks after completion of NSPT, and periodontally healthy, age- and gender-matched controls (n = 22). Leptin levels were estimated using enzyme linked immunosorbent assay kits. RESULTS At baseline, CP patients had significantly different periodontal clinical parameters and the leptin concentrations in saliva of CP patients were found to be significantly lower than periodontally healthy volunteers (4710.10 ± 1133.21 vs 8721.10 ± 1019.58 pg/ml) (p < 0.05), whereas in serum the leptin concentrations were significantly higher than healthy controls (10749 ± 2062.24 vs 8085.00 ± 2859.68 pg/ml). Significant improvement in periodontal parameters, serum and salivary leptin levels were observed in CP patients at 4 and 12 weeks post-therapy (p < 0.01). CONCLUSION Altered concentrations of leptin in serum and saliva are observed in CP patients which can be restored in favor of health after periodontal therapy.
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Affiliation(s)
- Parth Purwar
- Department of Periodontology, Faculty of Dental Sciences, King George's Medical University , Lucknow, Uttar Pradesh , India
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Purwar P, Khan MA, Mahdi AA, Pandey S, Singh B, Dixit J, Sareen S. Salivary and serum leptin concentrations in patients with chronic periodontitis. J Periodontol 2014; 86:588-94. [PMID: 25537001 DOI: 10.1902/jop.2014.140581] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
BACKGROUND The discovery of leptin has led to the elucidation of a robust physiologic system that not only maintains fat stores but is also an integral part of the host defense mechanism. However, leptin concentrations in the saliva of patients with chronic periodontitis (CP) has not been explored despite the potential role of salivary biomarkers in determining the presence, risk, and progression of periodontal disease. METHODS Eighty-four participants (44 with generalized severe CP and 40 without periodontitis) were enrolled. For each patient, the values of periodontal parameters were recorded, such as plaque index (PI), gingival index (GI), probing depth (PD), clinical attachment loss (AL), and percentage of sites with bleeding on probing (BOP) and clinical AL ≥5 mm. Saliva and serum samples were collected to estimate the leptin concentrations using enzyme-linked immunosorbent assay kits. Statistical analysis was performed using software. RESULTS Participants with CP demonstrated significantly higher BOP, PI, GI, and percentage of sites with clinical AL >5 mm (P <0.05). Leptin was detectable in all the clinical samples. Salivary leptin concentrations in patients with CP were significantly lower than in healthy volunteers (6,200.61 ± 2,322.11 versus 8,799.60 ± 901.70 pg/mL), whereas serum leptin concentrations were significantly higher in patients with CP than in healthy volunteers (11,600.00 ± 1,705.01 versus 7,616.62 ± 1,169.83 pg/mL). In addition, the results reflected a significant negative correlation of salivary leptin and a positive correlation of serum leptin with PD (P <0.05). CONCLUSION The results suggest that leptin concentrations in saliva and serum are significantly altered in CP and relate closely to current disease activity; however, further studies are needed to confirm the findings.
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Affiliation(s)
- Parth Purwar
- Department of Periodontology, Faculty of Dental Sciences, King George's Medical University, Lucknow, Uttar Pradesh, India
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Zhang Z, Wang F, Wang BJ, Chu G, Cao Q, Sun BG, Dai QY. Inhibition of leptin-induced vascular extracellular matrix remodelling by adiponectin. J Mol Endocrinol 2014; 53:145-54. [PMID: 24982243 PMCID: PMC4151455 DOI: 10.1530/jme-14-0027] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Vascular extracellular matrix (ECM) remodelling, which is the result of disruption in the balance of ECM synthesis and degradation, induces vessel fibrosis and thereby leads to hypertension. Leptin is known to promote tissue fibrosis, while adiponectin has recently been demonstrated to be anti-fibrogenic in tissue fibrosis. In this study, we aimed to evaluate the leptin-antagonist function of adiponectin and to further elucidate the mechanisms through which adiponectin dampens leptin signalling in vascular smooth muscle cells, thus preventing excess ECM production, in our already established 3D co-culture vessel models. Our 3D co-culture vessel model, which mimics true blood vessels, is composed of vascular endothelial cells, vascular smooth muscle cells and collagen type I. We validated the profibrogenic effects of leptin and analysed matrix metalloproteinase 2 (MMP2), MMP9, tissue inhibitor of metalloproteinase 1 (TIMP1) and collagen types II/IV secretion in 3D vessel models. The protective/inhibitory effects of adiponectin were re-analysed by inhibiting adiponectin receptor 1 (AdipoR) and AdipoR2 expression in endothelial cells using RNAi technology. In the 3D vessel models, adiponectin blocked the leptin-stimulated secretion of collagen types II/IV and TIMP1 while significantly increasing MMP2/9 activity. In endothelial cells, adiponectin induced phosphorylation of AMPK, thereby suppressing leptin-mediated STAT3 phosphorylation through induction of SOCS3 in smooth muscle cells. Our findings indicate that adiponectin disrupted the leptin-induced vascular ECM remodelling via AdipoR1 and enhanced AMPK signalling in endothelial cells, which, in turn, promoted SOCS3 up-regulation in smooth muscle cells to repress leptin-stimulated phosphorylation of STAT3.
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Affiliation(s)
- Zhi Zhang
- Department of CardiologySchool of Medicine, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai 200080, People's Republic of ChinaDepartment of CardiologyHuai'an First People's Hospital, Nanjing Medical University, Jiangsu Province 223300, People's Republic of China
| | - Fang Wang
- Department of CardiologySchool of Medicine, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai 200080, People's Republic of ChinaDepartment of CardiologyHuai'an First People's Hospital, Nanjing Medical University, Jiangsu Province 223300, People's Republic of China
| | - Bing-Jian Wang
- Department of CardiologySchool of Medicine, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai 200080, People's Republic of ChinaDepartment of CardiologyHuai'an First People's Hospital, Nanjing Medical University, Jiangsu Province 223300, People's Republic of China
| | - Guang Chu
- Department of CardiologySchool of Medicine, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai 200080, People's Republic of ChinaDepartment of CardiologyHuai'an First People's Hospital, Nanjing Medical University, Jiangsu Province 223300, People's Republic of China
| | - Qunan Cao
- Department of CardiologySchool of Medicine, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai 200080, People's Republic of ChinaDepartment of CardiologyHuai'an First People's Hospital, Nanjing Medical University, Jiangsu Province 223300, People's Republic of China
| | - Bao-Gui Sun
- Department of CardiologySchool of Medicine, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai 200080, People's Republic of ChinaDepartment of CardiologyHuai'an First People's Hospital, Nanjing Medical University, Jiangsu Province 223300, People's Republic of China
| | - Qiu-Yan Dai
- Department of CardiologySchool of Medicine, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai 200080, People's Republic of ChinaDepartment of CardiologyHuai'an First People's Hospital, Nanjing Medical University, Jiangsu Province 223300, People's Republic of China
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Gundala R, Chava VK, Ramalingam K. Association of Leptin in Periodontitis and Acute Myocardial Infarction. J Periodontol 2014; 85:917-24. [DOI: 10.1902/jop.2012.110620] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Li H, Yang X, Shi W, Ma Z, Feng G, Wang Q, Shen L, Xie C. Protective effects of nimodipine on cerebrovascular function in chronic alcoholic encephalopathy. Int J Mol Med 2013; 33:201-8. [PMID: 24173596 DOI: 10.3892/ijmm.2013.1540] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 10/17/2013] [Indexed: 11/05/2022] Open
Abstract
In the present study, we used chronic gavage administration of alcohol with gradual increases in alcohol concentration and volume to generate a rat model of chronic alcohol intoxication. We measured the changes in biological, behavioral, pathological and vascular injury-related molecular biological markers, and explored the effects of nimodipine intervention on alcohol intoxication. We found that chronic alcohol consumption induced a variety of behavioral abnormalities, accompanied by severe pathological changes in cerebral arterioles, prefrontal cortex and cerebellar tissue, as well as an upregulation of vascular endothelial growth factor (VEGF), leptin receptor (ob-R) and endothelin-1 (ET-1). Treatment with mimodipine for 15 days significantly improved behavioral abnormalities, alleviated the pathological changes in blood vessels and brain tissues, increased VEGF expression, decreased ob-R expression, reduced plasma ET-1 leakage and protected vascular and neuronal functions.
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Affiliation(s)
- Hui Li
- Department of Neurology, Jinan Fourth People's Hospital, Jinan, Shandong, P.R. China
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Syed Ikmal SIQ, Zaman Huri H, Vethakkan SR, Wan Ahmad WA. Potential biomarkers of insulin resistance and atherosclerosis in type 2 diabetes mellitus patients with coronary artery disease. Int J Endocrinol 2013; 2013:698567. [PMID: 24282409 PMCID: PMC3824310 DOI: 10.1155/2013/698567] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Accepted: 09/10/2013] [Indexed: 12/16/2022] Open
Abstract
Type 2 diabetes mellitus patients with coronary artery disease have become a major public health concern. The occurrence of insulin resistance accompanied with endothelial dysfunction worsens the state of atherosclerosis in type 2 diabetes mellitus patients. The combination of insulin resistance and endothelial dysfunction leads to coronary artery disease and ischemic heart disease complications. A recognized biological marker, high-sensitivity C-reactive protein, has been used widely to assess the progression of atherosclerosis and inflammation. Along with coronary arterial damage and inflammatory processes, high-sensitivity C-reactive protein is considered as an essential atherosclerosis marker in patients with cardiovascular disease, but not as an insulin resistance marker in type 2 diabetes mellitus patients. A new biological marker that can act as a reliable indicator of both the exact state of insulin resistance and atherosclerosis is required to facilitate optimal health management of diabetic patients. Malfunctioning of insulin mechanism and endothelial dysfunction leads to innate immune activation and released several biological markers into circulation. This review examines potential biological markers, YKL-40, alpha-hydroxybutyrate, soluble CD36, leptin, resistin, interleukin-18, retinol binding protein-4, and chemerin, as they may play significant roles in insulin resistance and atherosclerosis in type 2 diabetes mellitus patients with coronary artery disease.
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Affiliation(s)
| | - Hasniza Zaman Huri
- Department of Pharmacy, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Clinical Investigation Centre, 13th Floor Main Tower, University Malaya Medical Centre, 59100 Lembah Pantai, Kuala Lumpur, Malaysia
- *Hasniza Zaman Huri:
| | - Shireene Ratna Vethakkan
- Endocrinology Unit, Department of Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Wan Azman Wan Ahmad
- Clinical Investigation Centre, 13th Floor Main Tower, University Malaya Medical Centre, 59100 Lembah Pantai, Kuala Lumpur, Malaysia
- Cardiology Unit, Department of Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
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Kumagai S, Kishimoto H, Zou B. The leptin to adiponectin ratio is a good biomarker for the prevalence of metabolic syndrome, dependent on visceral fat accumulation and endurance fitness in obese patients with diabetes mellitus. Metab Syndr Relat Disord 2012; 3:85-94. [PMID: 18370715 DOI: 10.1089/met.2005.3.85] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND We investigated the contribution of adiponectin or leptin on the prevalence of metabolic syndrome (MS), while also taking cardiorespiratory fitness and visceral fat accumulation into account regarding diabetes patients. METHODS Japanese male patients (n = 77) with either impaired glucose tolerance (IGT) or type 2 diabetes mellitus were divided into three tertiles according to their adipocytokine levels. A logistic regression analysis was performed after adjusting for age to investigate the association between the adipocytokine levels and the prevalence of MS based on World Health Organization (WHO) criteria. RESULTS The visceral fat area (VFA) and maximal oxygen uptake ([Formula: see text] O(2)max) were found to be significantly different within the tertiles regarding the leptin and adiponectin levels and the adiponectin-to-leptin (A/L) ratio. The low tertile of leptin showed a significantly lower odds ratio (OR) for prevalence of MS than that in the high group. Both the low and the medium tertiles of adiponectin showed a significantly higher OR for prevalence of SM than that of the high group. Especially, the low tertile of A/L ratio had about an eight times higher prevalence of MS than the high tertile, and the difference was significant. However, when both the VFA and/or [Formula: see text] O(2)max were added to the logistic regression model as adjusting factors, all of these significant differences disappeared. CONCLUSION The A/L ratio is suggested to be a good biomarker for the prevalence of MS in comparison to the adiponectin and leptin levels alone. However, these relationships are dependent on abdominal fat accumulation and/or cardiorespiratory fitness levels.
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Affiliation(s)
- Shuzo Kumagai
- Institute of Health Science, Fukuoka University, Fukuoka, Japan
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Martin SS, Qasim AN, Rader DJ, Reilly MP. C-reactive protein modifies the association of plasma leptin with coronary calcium in asymptomatic overweight individuals. Obesity (Silver Spring) 2012; 20:856-61. [PMID: 21738237 PMCID: PMC4005808 DOI: 10.1038/oby.2011.164] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Evidence suggests putative interactions of leptin and C-reactive protein (CRP) in the pathogenesis of adiposity-related atherosclerotic cardiovascular disease (CVD). Therefore, we investigated whether CRP levels modify the relationship of leptin levels with coronary artery calcium (CAC). We examined 1,460 asymptomatic individuals from two community-based cross-sectional studies coordinated at a single, university-based research center. We focused on subjects who were overweight or obese (BMI ≥25) given greater biologic plausibility in this setting. In multivariable CAC models, we analyzed the interaction of log-transformed plasma leptin levels with higher CRP levels as defined by three cut-points: two clinically based (2 mg/l, 3 mg/l) and one dataset specific (sex-specific upper quartile). The association of plasma leptin with CAC was modified by higher CRP regardless of cut-point (interaction term P values all <0.01 in fully adjusted models). Leptin levels were associated with CAC in those with high, but not low CRP levels (e.g., tobit ratio for a 1 unit increase in ln(leptin) (95% CI): 2.18 (1.29-3.66) if CRP level ≥3 mg/l; N = 461 vs. 0.94 (0.67-1.31) if CRP levels <3 mg/l; N = 999) in fully adjusted models. No interaction with CRP was present in control analyses with adiponectin, BMI and waist circumference. In conclusion, in asymptomatic overweight and obese adults, increased leptin levels were independently associated with increased CAC in the presence of high, but not low CRP levels, supporting a leptin-CRP interface in atherosclerosis risk.
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Affiliation(s)
- Seth S. Martin
- Cardiovascular Institute, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, USA
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | - Atif N. Qasim
- Cardiovascular Institute, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, USA
| | - Dan J. Rader
- Cardiovascular Institute, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, USA
- Institute of Diabetes, Obesity and Metabolism, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, USA
- Institute for Translational Medicine and Therapeutics, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, USA
| | - Muredach P. Reilly
- Cardiovascular Institute, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, USA
- Institute of Diabetes, Obesity and Metabolism, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, USA
- Institute for Translational Medicine and Therapeutics, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, USA
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Shoukry A, El-Sherbieny I, Swelam E. Association of insulin resistance, insulin and leptin levels with coronary in-stent restenosis. Egypt Heart J 2012. [DOI: 10.1016/j.ehj.2011.08.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Carotid intima-media thickness and serum leptin in psoriasis. Herz 2011; 37:527-33. [PMID: 22127739 DOI: 10.1007/s00059-011-3547-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 08/17/2011] [Accepted: 10/05/2011] [Indexed: 10/15/2022]
Abstract
BACKGROUND Psoriasis, a chronic inflammatory immune disorder, has been linked to increased cardiovascular mortality and morbidity. Leptin, an obesity-related peptide, has been shown to exert direct effects on the vascular endothelium and on vascular smooth muscle cells. Carotid intima-media thickness (IMT) measurement is a promising tool for detecting atherosclerosis in its pre-occlusive/subclinical phase. OBJECTIVE The objective of the study was to evaluate carotid IMT and serum leptin levels in psoriatic patients as an indicator of subclinical atherosclerosis. MATERIALS AND METHODS The study was conducted in 50 psoriatic patients and 10 healthy controls. The clinical severity of skin affection in psoriatic patients was estimated using the psoriatic area and severity index (PASI). Serum leptin levels (ng\ml) and lipid profiles [including serum triglyceride (TG), serum low density lipoproteins (LDL) and serum high density lipoproteins (HDL)] were measured from blood samples. Carotid IMT was measured using carotid duplex ultrasonography. RESULTS Psoriatic patients showed significantly higher leptin levels and higher IMT than controls. The mean of the intima-media thickness of the four vessels examined (MIMT) showed a positive correlation with patients' mean ages, disease duration, body mass index, PASI scores, systolic blood pressure, diastolic blood pressure, leptin levels, LDL levels and triglyceride levels and no correlation with the mean HDL level. CONCLUSION Psoriasis is an independent risk factor for subclinical atherosclerosis. This cardiovascular impairment is influenced mainly by disease severity, serum TG levels and serum leptin levels.
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Aronis KN, Diakopoulos KN, Fiorenza CG, Chamberland JP, Mantzoros CS. Leptin administered in physiological or pharmacological doses does not regulate circulating angiogenesis factors in humans. Diabetologia 2011; 54:2358-67. [PMID: 21660636 PMCID: PMC3733553 DOI: 10.1007/s00125-011-2201-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 04/26/2011] [Indexed: 12/31/2022]
Abstract
AIM/HYPOTHESIS Leptin has been shown to regulate angiogenesis in animal and in vitro studies by upregulating the production of several pro-angiogenic factors, but its role in regulating angiogenesis has never been studied in humans. METHODS The potential angiogenic effect of two doses of metreleptin (50 and 100 ng/ml) was evaluated in vitro, using a novel three-dimensional angiogenesis assay. Fifteen healthy, normoleptinaemic volunteers were administered both a physiological (0.1 mg/kg) and a pharmacological (0.3 mg/kg) single dose of metreleptin, in vivo, on two different inpatient admissions separated by 1-12 weeks. Serum was collected at 0, 6, 12 and 24 h after metreleptin administration. Twenty lean women, with leptin levels <5 ng/ml, were randomised in a 1:1 fashion to receive either physiological replacement doses of metreleptin (0.04-0.12 mg/kg q.d.) or placebo for 32 weeks. Serum was collected at 0, 8, 20 and 32 weeks after randomisation. Proteomic angiogenesis array analysis was performed to screen for angiogenic factors. Circulating concentrations of angiogenin, angiopoietin-1, platelet derived endothelial factor (PDGF)-AA, matrix metalloproteinase (MMP) 8 and 9, endothelial growth factor (EGF) and vascular EGF (VEGF) were also measured. RESULTS Both metreleptin doses failed to induce angiogenesis in the in vitro model. Although leptin levels increased significantly in response to both short-term and long-term metreleptin administration, circulating concentrations of angiogenesis markers did not change significantly in vivo. CONCLUSIONS/INTERPRETATIONS This is the first study that examines the effect of metreleptin administration in angiogenesis in humans. Metreleptin administration does not regulate circulating angiogenesis related factors in humans. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov NCT00140205 and NCT00130117. FUNDING This study was supported by National Institutes of Health-National Center for Research Resources grant M01-RR-01032 (Harvard Clinical and Translational Science Center) and grant number UL1 RR025758. Funding was also received from the National Institute of Diabetes and Digestive and Kidney Diseases grants 58785, 79929 and 81913, and AG032030.
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Affiliation(s)
- K. N. Aronis
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - K. N. Diakopoulos
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - C. G. Fiorenza
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - J. P. Chamberland
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - C. S. Mantzoros
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA. Section of Endocrinology, Boston VA Healthcare System, Harvard Medical School, Boston, MA, USA. Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA
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Karakas M, Zierer A, Herder C, Baumert J, Meisinger C, Koenig W, Thorand B. Leptin, adiponectin, their ratio and risk of Coronary Heart Disease: results from the MONICA/KORA Augsburg Study 1984-2002. Atherosclerosis 2009; 209:220-5. [PMID: 19732895 DOI: 10.1016/j.atherosclerosis.2009.08.020] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Revised: 07/29/2009] [Accepted: 08/11/2009] [Indexed: 01/27/2023]
Abstract
OBJECTIVE Despite modulating a number of metabolic processes linked to atherosclerosis, including glucose regulation, hematopoiesis, fatty acid catabolism and angiogenesis, the potential association of adiponectin and leptin with coronary heart disease is still a matter of controversy. METHODS We conducted a population-based case-cohort study within the MONICA/KORA Augsburg studies. Serum levels of adipokines were measured in 333 case subjects with incident CHD and 1,728 non-case subjects selected from a source population of 9300 middle-aged men and women. Mean follow-up was 10.8+/-4.6 years. We sought to analyze the association of leptin and adiponectin and their ratio with CHD. RESULTS After adjustment for various confounding factors the hazard ratios and 95% confidence intervals comparing tertile extremes were 0.79 (0.53-1.17) for leptin (top vs bottom tertile) and 0.87 (0. 62-1.23) for adiponectin (bottom vs top tertile), respectively. Furthermore, the ratio of leptin/adiponectin also showed no association with CHD (HR 1.01 (0.68-1.51)). CONCLUSIONS The present study reports the association of leptin and adiponectin with incident CHD in a large population-based cohort. In contrast to fairly strong associations previously reported, our findings indicate no clinically relevant association between leptin, adiponectin and their ratio with the risk of CHD after adjustment for potential confounders.
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Affiliation(s)
- Mahir Karakas
- University of Ulm Medical Center, Department of Internal Medicine II-Cardiology, Albert-Einstein-Allee 23, Ulm, Germany
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Martin SS, Qasim A, Reilly MP. Leptin resistance: a possible interface of inflammation and metabolism in obesity-related cardiovascular disease. J Am Coll Cardiol 2008; 52:1201-10. [PMID: 18926322 DOI: 10.1016/j.jacc.2008.05.060] [Citation(s) in RCA: 340] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Accepted: 05/28/2008] [Indexed: 01/19/2023]
Abstract
Leptin is an adipocyte-derived hormone and cytokine that regulates energy balance through a wide range of functions, including several that are important to cardiovascular health. Increased circulating leptin, a marker of leptin resistance, is common in obesity and independently associated with insulin resistance and cardiovascular disease (CVD) in humans. The mechanisms of leptin resistance include genetic mutation, leptin self-regulation, limited tissue access, and cellular or circulating molecular regulation. Evidence suggests that central leptin resistance causes obesity and that obesity-induced leptin resistance injures numerous peripheral tissues, including liver, pancreas, platelets, vasculature, and myocardium. This metabolic- and inflammatory-mediated injury may result from either resistance to leptin's action in selective tissues, or excess leptin action from adiposity-associated hyperleptinemia. In this sense, the term "leptin resistance" encompasses a complex pathophysiological phenomenon. The leptin axis has functional interactions with elements of metabolism, such as insulin, and inflammation, including mediators of innate immunity, such as interleukin-6. Leptin is even purported to physically interact with C-reactive protein, resulting in leptin resistance, which is particularly intriguing, given C-reactive protein's well-studied relationship to cardiovascular disease. Given that plasma levels of leptin and inflammatory markers are correlated and also predict cardiovascular risk, it is conceivable that part of this risk may be mediated through leptin resistance-related insulin resistance, chronic inflammation, type II diabetes, hypertension, atherothrombosis, and myocardial injury. Leptin resistance and its interactions with metabolic and inflammatory factors, therefore, represent potential novel diagnostic and therapeutic targets in obesity-related cardiovascular disease.
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Affiliation(s)
- Seth S Martin
- Department of Medicine, Cardiovascular Institute, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6160, USA
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Schneiderman J, Simon AJ, Schroeter MR, Flugelman MY, Konstantinides S, Schaefer K. Leptin receptor is elevated in carotid plaques from neurologically symptomatic patients and positively correlated with augmented macrophage density. J Vasc Surg 2008; 48:1146-55. [DOI: 10.1016/j.jvs.2008.06.054] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2008] [Revised: 06/23/2008] [Accepted: 06/23/2008] [Indexed: 11/16/2022]
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Yang J, Zhao SP, Li J, Dong SZ. Effect of niacin on adipocyte leptin in hypercholesterolemic rabbits. Cardiovasc Pathol 2008; 17:219-25. [PMID: 18402819 DOI: 10.1016/j.carpath.2007.09.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Revised: 08/28/2007] [Accepted: 09/19/2007] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Leptin may play an important role in the development of atherosclerosis. Several transcription genes [including peroxisome proliferator-activated receptor gamma (PPARgamma) and CD36] involved in lipid and glucose metabolism and inflammatory processes may correlate to leptin expression. The aim of this study was to investigate the effect of niacin on serum leptin levels in hypercholesterolemic rabbits and the expression of leptin, PPARgamma, and CD36 in adipocytes from hypercholesterolemic rabbits. METHODS Eighteen rabbits fed with high-cholesterol diet for 8 weeks were randomly divided into two groups: (a) high-cholesterol group (n=6), which is maintained on high-cholesterol diet for 6 weeks, and (b) niacin group (n=6), which receives the same cholesterol diet plus niacin (200 mg/kg/day) for 6 weeks. The control group (n=6) was fed with normal diet for 14 weeks. Subcutaneous adipose was collected for RNA analysis. The direct effect of niacin on leptin release was assayed in hypercholesterolemic rabbit adipocytes. Leptin levels in serum and adipocyte culture supernatant were measured via enzyme-linked immunosorbent assay. RT-PCR was used to evaluate leptin, PPARgamma, and CD36 mRNA expression in adipose and adipocytes. RESULTS Compared with the control group, rabbits fed with high-cholesterol diets showed higher levels of serum total cholesterol, low-density lipoprotein cholesterol, and leptin, all of which were significantly reduced by niacin treatment. After 6 weeks of treatment with niacin, the leptin level was significantly decreased by 21.8% (6.87+/-1.58 vs. 8.79+/-1.45, P<.05) and leptin mRNA expression of adipose was significantly lower in rabbits treated with niacin than in those fed with high-cholesterol diet continuously (0.58+/-0.11 vs. 0.73+/-0.15, P<.05). Niacin dose-dependently inhibited leptin secretion and increased CD36 and PPARgamma expression in cultured adipocytes. The reduction of leptin mRNA expression of hypercholesterolemic rabbits by niacin was negatively correlated with the up-regulation of PPARgamma and CD36 mRNA expression by niacin (r=-.69 and r=-.63, respectively, P<.01). CONCLUSION Niacin can reduce serum level and adipose mRNA expression of leptin and up-regulate PPARgamma and CD36 mRNA expression in hypercholesterolemic rabbits.
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Affiliation(s)
- Jun Yang
- Department of Cardiology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, PR China.
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Raggi P, Kleerekoper M. Contribution of Bone and Mineral Abnormalities to Cardiovascular Disease in Patients with Chronic Kidney Disease: Figure 1. Clin J Am Soc Nephrol 2008; 3:836-43. [DOI: 10.2215/cjn.02910707] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Sugiyama A, Wada Y, Izumi A, Kobayashi M, Kohro T, Patrick CR, Hamakubo T, Kodama T. Transcriptional activation by hypoxia and low-density lipoprotein loading in cultured vascular smooth muscle cells. J Atheroscler Thromb 2007; 14:226-34. [PMID: 17938544 DOI: 10.5551/jat.e444] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
AIM The aim of this study was to investigate transcriptional activation in vascular SMC cultured under hypoxic conditions and high low-density lipoprotein (LDL) levels. METHODS We cultured vascular SMC under hypoxic conditions and high LDL levels, and RNA expression profiles for more than 5800 were analyzed by DNA microarray. We performed promoter sequence analysis of genes induced by the combination of hypoxia and high LDL level conditions. RESULTS In human coronary arterial SMC, the combination of hypoxia and high LDL level conditions induced the expression of 40 genes. Genes induced during the first 24 hours were known to be involved in inflammation, while late genes induced during 48 to 72 hours were composed primarily of genes involved in lipid and/or glucose metabolism. Promoter sequence analysis of these genes revealed that 39 of the 40 genes possessed multiple hypoxic response elements (HRE). The most induced gene in the combination of hypoxia and high LDL level conditions was the leptin gene. Functional analysis of the 3 kb leptin promoter revealed that HRE at-166 mediated transcriptional activation by hypoxia, but 3 kb reporter constructs can not reproduce the additive affect of LDL under hypoxia. CONCLUSION These results support the hypothesis that an HRE-mediated mechanism may be involved in transcriptional activation during lipid deposition in vascular SMC induced by hypoxia and LDL loading, but additional mechanisms may be involved in the synergistic action induced by LDL.
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Affiliation(s)
- Akira Sugiyama
- Laboratory for System Biology and Medicine, RCAST, The University of Tokyo, Tokyo, Japan
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Schroeter MR, Schneiderman J, Schumann B, Glückermann R, Grimmas P, Buchwald AB, Tirilomis T, Schöndube FA, Konstantinides SV, Schäfer K. Expression of the leptin receptor in different types of vascular lesions. Histochem Cell Biol 2007; 128:323-33. [PMID: 17680264 DOI: 10.1007/s00418-007-0319-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/17/2007] [Indexed: 12/21/2022]
Abstract
Clinical and experimental evidence suggests that the adipokine leptin may be important for the development of cardiovascular complications associated with obesity, possibly through interaction with its receptor on vascular cells. In the present study, we systematically analysed expression of the leptin receptor in normal and diseased vascular specimens using immunohistochemistry, immunofluorescence and quantitative real time-PCR. In particular, human atherosclerotic plaques as well as experimental vascular lesions induced in hypercholesterolemic mice and minipigs, respectively, were examined. Our results demonstrate the presence of the leptin receptor in normal vessel wall segments as well as neointimal or atherosclerotic lesions. In the latter, ObR expressing cells were predominantly localised on the luminal border and within the subintima, and coexpression of von Willebrand factor, VEGF receptor-2 or VE cadherin identified them as endothelial cells. Moreover, CD14-positive monocytes/macrophages were strongly positive for the leptin receptor. In contrast, only few ObR-expressing smooth muscle cells could be detected in human atherosclerotic plaques. The findings of the present study thus support a possible action of leptin on the cardiovascular system by demonstrating expression of the leptin receptor in different types of vascular lesions.
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Affiliation(s)
- Marco R Schroeter
- Department of Cardiology and Pulmonary Medicine, Georg August University of Göttingen, Göttingen, Germany
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Karthikeyan BV, Pradeep AR. Leptin levels in gingival crevicular fluid in periodontal health and disease. J Periodontal Res 2007; 42:300-4. [PMID: 17559625 DOI: 10.1111/j.1600-0765.2006.00948.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVE A high concentration of leptin is associated with healthy gingival tissue, and the concentration of leptin decreases as periodontal disease progresses. However, to date, the leptin concentration in gingival crevicular fluid has not been documented. Hence, the present study was carried out to explore the presence of leptin in gingival crevicular fluid in periodontal health and disease, and to probe further into its possible role in periodontal disease progression. MATERIAL AND METHODS A total of 45 adult patients were selected, based on their body mass index, for the study. They were categorized into three groups of 15 patients each, based on their periodontal tissue status, as follows: group I (clinically healthy gingiva with no loss of attachment); group II (chronic gingivitis with no loss of attachment); and group III (chronic periodontitis). Gingival crevicular fluid samples of 1 microL were collected extracrevicularly using white color-coded 1-5 microL calibrated volumetric microcapillary pipettes from one site in each person, and samples were analyzed for leptin using a commercially available enzyme-linked immunosorbent assay kit. RESULTS The concentration of leptin in gingival crevicular fluid of patients in group I (2292.69 pg/mL) was statistically higher (p < 0.05) than in those of groups II (1409.95 pg/mL) and III (1071.89 pg/mL). This suggests a negative correlation of gingival crevicular fluid leptin concentration with clinical attachment loss (p < 0.05). CONCLUSION As periodontal tissue destruction increased, there was a substantial decrease in gingival crevicular fluid leptin concentration. This observation extends our knowledge of the protective role of leptin in periodontal health.
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Affiliation(s)
- B V Karthikeyan
- Department of Periodontics, Government Dental College and Hospital, Bangalore, India.
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Karthikeyan BV, Pradeep AR. Gingival crevicular fluid and serum leptin: their relationship to periodontal health and disease. J Clin Periodontol 2007; 34:467-72. [PMID: 17451417 DOI: 10.1111/j.1600-051x.2007.01078.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND & AIMS Leptin is a pleiotrophic hormone produced by adipose tissue and it plays an important role in protection of the host from inflammation and infection. The purpose of this study is to determine the presence of leptin in gingival crevicular fluid (GCF) and serum samples and to find out their association, if any. METHODS Forty two subjects were selected based on their body mass index and were divided into three groups of 14 each; healthy (Group I), chronic gingivitis (Group II) and chronic periodontitis (Group III). GCF samples (by microcapillary pipettes) and serum samples (by venipuncture) were collected to estimate the levels of leptin using enzyme linked immunosorbent assay kit. RESULTS The highest mean leptin concentration in GCF was obtained for Group I (2658 pg/ml) and the least for Group III (1312 pg/ml). In contrast, the lowest serum leptin concentration was obtained for the Group I (8783 pg/ml), and the highest for Group III (12082 pg/ml). This suggests a negative correlation of GCF leptin concentration and a positive correlation of serum leptin concentration as the clinical attachment level progresses (p<0.05). CONCLUSION These results suggest that greater the periodontal destruction, lesser is the GCF leptin concentration and greater the serum leptin concentration.
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Affiliation(s)
- B V Karthikeyan
- Department of Periodontics, Government Dental College and Hospital, Bangalore, India.
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Iribarren C, Husson G, Go AS, Lo JC, Fair JM, Rubin GD, Hlatky MA, Fortmann SP. Plasma leptin levels and coronary artery calcification in older adults. J Clin Endocrinol Metab 2007; 92:729-32. [PMID: 17148566 DOI: 10.1210/jc.2006-1138] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Leptin is associated with adiposity and insulin resistance and may play a direct role in vascular calcification. It is unclear, however, whether leptin is an independent predictor of atherosclerotic burden. OBJECTIVE The aim of this study was to examine the association between plasma leptin and coronary artery calcification (CAC) in an ethnically diverse cohort of older adult men and women free of clinical cardiovascular disease. DESIGN This was a cross-sectional study with data collection between January 2002 and February 2004 as part of the ADVANCE Study. SETTING The study was conducted at an integrated health care delivery system in Northern California. PARTICIPANTS Participants included 949 men and women aged 60-69 yr old. INTERVENTIONS There were no interventions. MAIN OUTCOME MEASURE The main outcome measure was CAC by multidetector row computed tomography. RESULTS In ordinal logistic regression, plasma leptin levels were positively associated with extent of CAC independently of age, race/ethnicity, and smoking status in women (odds ratio of higher CAC for the sex-specific upper tertile vs. lower tertile = 1.81; 95% confidence interval, 1.10-3.00) but not in men (odds ratio = 1.29; 95% confidence interval = 0.89-1.86). However, this association was explained by metabolic risk factors and adiposity measures. CONCLUSIONS Our findings support a role of leptin on vascular calcification in women but, in our sample of older adults, the association between leptin and CAC was not independent of other cardiac risk factors.
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Affiliation(s)
- Carlos Iribarren
- Kaiser Permanente, Division of Research, 2000 Broadway, Oakland, California 94612, USA.
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Kwon K, Choi K, Park SH. Leptin is Associated with Endothelial Dysfunction in Healthy Obese Premenopausal Women. Korean Circ J 2007. [DOI: 10.4070/kcj.2007.37.6.251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Kihwan Kwon
- Cardiovascular Center, Department of Internal Medicine, Ewha Womans University, School of Medicine, Seoul, Korea
- Ewha Medical Research Institute, Ewha Womans University, School of Medicine, Seoul, Korea
| | | | - Si-Hoon Park
- Cardiovascular Center, Department of Internal Medicine, Ewha Womans University, School of Medicine, Seoul, Korea
- Ewha Medical Research Institute, Ewha Womans University, School of Medicine, Seoul, Korea
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Wu ZH, Zhao SP. Adipocyte: a potential target for the treatment of atherosclerosis. Med Hypotheses 2006; 67:82-6. [PMID: 16500036 DOI: 10.1016/j.mehy.2005.12.042] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Accepted: 12/23/2005] [Indexed: 11/30/2022]
Abstract
Obesity is an independent risk factor for coronary heart disease, whereas the underlying mechanisms have not been fully elucidated. Adipocytes may produce various adipokines with favorable and unfavorable cardiovascular effects. The dysregulated secretion of adipokines by adipocytes may contribute to obese associated atherosclerosis. Adipocytes can also function as phagocytes to uptake and degrade oxidized low-density lipoprotein (Ox-LDL), suggesting that adipocytes possibly involve in clearance of Ox-LDL in blood. The dysfunctional adipocytes might be implicated in the atherogenesis. Some cardioprotective drugs mediate their cardiovascular benefits partly through their direct beneficial effects on adipocytes. Therefore, we hypothesized that adipocytes might be potential target for the treatment of atherosclerosis.
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Affiliation(s)
- Zhi-hong Wu
- Department of Cardiology, The Second Xiangya Hospital of Central South University, Middle Ren-Min Road No. 86, Changsha, Hunan 410011, PR China.
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Beltowski J, Jamroz-Wiśniewska A, Borkowska E, Wójcicka G. Differential effect of antioxidant treatment on plasma and tissue paraoxonase activity in hyperleptinemic rats. Pharmacol Res 2006; 51:523-32. [PMID: 15829432 DOI: 10.1016/j.phrs.2005.01.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/31/2005] [Indexed: 11/26/2022]
Abstract
Recent studies suggest that adipose tissue hormone, leptin, is involved in atherogenesis, especially in obese subjects. Previously, we have demonstrated that experimentally induced hyperleptinemia decreases plasma paraoxonase 1 (PON1) activity. The aim of this study was to investigate whether treatment with synthetic antioxidant, Tempol, modulates the effect of leptin on plasma and tissue PON1 in the rat. Leptin was administered at a dose of 0.25 mgkg-1 s.c. twice daily for 7 days and Tempol was added to the drinking water at a concentration of 2 mM. Leptin reduced plasma PON1 activity toward paraoxon, phenyl acetate and gamma-decanolactone to 71.1, 72.3 and 57.1% of control, respectively. In addition, leptin decreased PON1 activity toward paraoxon in aorta, renal cortex and medulla to 78.6, 49.2 and 48.0% of control, respectively, but had no effect on PON1 in heart, lung and liver. PON1 activity toward phenyl acetate was lower following leptin treatment only in aorta. Leptin increased plasma concentration and urinary excretion of isoprostanes as well as malonyldialdehyde + 4-hydroxyalkenals level in aorta, renal cortex and renal medulla. Coadministration of Tempol prevented leptin-induced oxidative stress and normalized PON1 activity in aorta and kidney. However, Tempol had no effect on plasma PON1 in leptin-treated rats. These data indicate that hyperleptinemia decreases tissue PON1 activity through oxidative stress-dependent mechanism. In contrast, leptin-induced downregulation of plasma PON1 is not mediated by oxidative stress.
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Affiliation(s)
- Jerzy Beltowski
- Department of Pathophysiology, Medical University, ul. Jaczewskiego 8, 20-090 Lublin, Poland.
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Abstract
The objectives of this study were to explore whether ovarian vascular endothelial growth factor (VEGF) expression in mice can be regulated by IL-6 (interleukin-6), angiotensin II, FSH, and hCG; and to test whether the mouse ovarian VEGF expression can result in angiogenesis. The ICR mice were sacrificed, and their ovaries were recovered. Recovered ovaries were treated with IL-6, angiotensin II, FSH, and hCG separately and incubated for 24 hours in alpha-MEM. Expression of mRNA and protein of VEGF were assessed by RT-PCR and immunohistochemistry. The resulting angiogenesis was evaluated through immunohistochemical analysis for CD34. Treatment of mice ovaries with IL-6, FSH, and hCG resulted in a significant increase of VEGF mRNA, and IL-6 was the most potent inducer of VEGF. IL-6 and FSH resulted in increased neovascularization in the follicular phase of mouse ovaries. In contrast, angiotensin II could not increase VEGF expression or neovascularization. We documented an in vitro increase in VEGF expression by IL-6, FSH, and hCG; and reaffirmed that the proliferative response of murine ovarian endothelial cells paralleled an increase of VEGF expression.
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Affiliation(s)
- So-Young Shin
- Department of Obstetrics & Gynecology, Eulji University School of Medicine, Seoul, Korea
| | - Ho-Jung Lee
- Department of Pathology, Eulji University School of Medicine, Seoul, Korea
| | - Duck-Sung Ko
- Eulji Life Science Institute, Eulji University School of Medicine, Seoul, Korea
| | - Hoi-Chang Lee
- Eulji Life Science Institute, Eulji University School of Medicine, Seoul, Korea
| | - Won Il Park
- Department of Obstetrics & Gynecology, Eulji University School of Medicine, Seoul, Korea
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Zhao SP, Wu ZH. Atorvastatin reduces serum leptin concentration in hypercholesterolemic rabbits. Clin Chim Acta 2005; 360:133-40. [PMID: 16014304 DOI: 10.1016/j.cccn.2005.04.021] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Revised: 04/07/2005] [Accepted: 04/12/2005] [Indexed: 11/17/2022]
Abstract
BACKGROUND Leptin may play an important role in the development of atherosclerosis. We evaluated the effect of atorvastatin on leptin secretion in vivo and in vitro. METHODS Sixteen rabbits fed with high-cholesterol diet for 8 weeks were randomly divided into 2 groups: (1) high cholesterol diet for 6 weeks (n=8), and (2) the same cholesterol diet plus atorvastatin (2.5 mg/kg/day) for 6 weeks (n=8). A control group (n=5) was fed with normal diet for 14 weeks. Subcutaneous adipose was collected for RNA analysis. The direct effect of atorvastatin on leptin release was assayed in primary rabbit adipocytes. Leptin levels in serum and adipocytes culture supernatant were measured by ELISA. RT-PCR was used to evaluate leptin mRNA expressions in adipose and adipocytes. RESULTS Compared with control group, rabbits fed with high cholesterol diet showed higher levels of serum total cholesterol, LDL cholesterol and leptin, all of which were significantly reduced by atorvastatin treatment. Leptin mRNA expression of adipose was significant lower in rabbits treated with atorvastatin than those fed with high cholesterol diet continuously (0.81+/-0.31 vs. 1.23+/-0.36, P<0.05). Atorvastatin dose-dependently inhibited leptin secretion and mRNA expression in cultured adipocytes. CONCLUSION Atorvastatin can inhibit leptin release and mRNA expression, and reduces serum leptin level in hypercholesterolemic rabbits.
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Affiliation(s)
- Shui-ping Zhao
- Department of Cardiology, The Second Xiangya Hospital of Central South University, middle Ren-Min road No.86, Changsha, Hunan 410011, PR China.
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44
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Li L, Mamputu JC, Wiernsperger N, Renier G. Signaling pathways involved in human vascular smooth muscle cell proliferation and matrix metalloproteinase-2 expression induced by leptin: inhibitory effect of metformin. Diabetes 2005; 54:2227-34. [PMID: 15983226 DOI: 10.2337/diabetes.54.7.2227] [Citation(s) in RCA: 147] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Accumulating evidence suggests that high concentrations of leptin observed in obesity and diabetes may contribute to their adverse effects on cardiovascular health. Metformin monotherapy is associated with reduced macrovascular complications in overweight patients with type 2 diabetes. It is uncertain whether such improvement in the cardiovascular outcome is related to specific vasculoprotective effects of this drug. In the present study, we determined the effect of leptin on human aortic smooth muscle cell (HASMC) proliferation and matrix metalloproteinase (MMP)-2 expression, the signaling pathways mediating these effects, and the modulatory effect of metformin on these parameters. Incubation of HASMCs with leptin enhanced the proliferation and MMP-2 expression in these cells and increased the generation of intracellular reactive oxygen species (ROS). These effects were abolished by vitamin E. Inhibition of NAD(P)H oxidase and protein kinase C (PKC) suppressed the effect of leptin on ROS production. In HASMCs, leptin induced PKC, extracellular signal-regulated kinase (ERK)1/2, and nuclear factor-kappaB (NF-kappaB) activation and inhibition of these signaling pathways abrogated HASMC proliferation and MMP-2 expression induced by this hormone. Treatment of HASMCs with metformin decreased leptin-induced ROS production and activation of PKC, ERK1/2, and NF-kappaB. Metformin also inhibited the effect of leptin on HASMC proliferation and MMP-2 expression. Overall, these results demonstrate that leptin induced HASMC proliferation and MMP-2 expression through a PKC-dependent activation of NAD(P)H oxidase with subsequent activation of the ERK1/2/NF-kappaB pathways and that therapeutic metformin concentrations effectively inhibit these biological effects. These results suggest a new mechanism by which metformin may improve cardiovascular outcome in patients with diabetes.
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Affiliation(s)
- Ling Li
- CHUM Research Centre, Notre-Dame Hospital, 1560 Sherbrooke St. East, Room Y-3622, Montreal, Quebec, Canada H2L 4M1
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45
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Shin HJ, Oh J, Kang SM, Lee JH, Shin MJ, Hwang KC, Jang Y, Chung JH. Leptin induces hypertrophy via p38 mitogen-activated protein kinase in rat vascular smooth muscle cells. Biochem Biophys Res Commun 2005; 329:18-24. [PMID: 15721267 DOI: 10.1016/j.bbrc.2004.12.195] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2004] [Indexed: 11/30/2022]
Abstract
The hypertrophy of vascular smooth muscle cells (VSMCs) is critical in vascular remodeling associated with hypertension, atherosclerosis, and restenosis. Recently, leptin has appeared to play a pivotal role in vascular remodeling. However, the mechanism by which leptin induces hypertrophy in vascular smooth muscle cells is still unknown. We studied the role of leptin as a potential hypertrophic factor in rat VSMCs. In the present study, leptin significantly increased [(3)H]leucine incorporation and the total protein/DNA ratio in VSMCs. The maximal hypertrophic effect was at 100ng/ml of leptin. Leptin induced phosphorylation and activation of p38 mitogen-activated protein (p38 MAP) kinase and of signal transducers and activators of transcription 3 in a concentration- and time-dependent manner. A p38 MAP kinase inhibitor SB203580 significantly inhibited leptin-induced hypertrophy, AG490 (a JAK2 inhibitor) partially inhibited it, and other MAP kinase inhibitors, PD98059 (an ERK inhibitor) and SP600125 (a JNK inhibitor), had no effect. These results indicate that leptin directly stimulates cellular hypertrophy via p38 MAP kinase in rat VSMCs.
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MESH Headings
- Animals
- Anthracenes/pharmacology
- Aorta/metabolism
- Arteriosclerosis
- Blotting, Western
- Cells, Cultured
- DNA/metabolism
- DNA-Binding Proteins/metabolism
- Dose-Response Relationship, Drug
- Electrophoresis, Polyacrylamide Gel
- Enzyme Activation
- Enzyme Inhibitors/pharmacology
- Flavonoids/pharmacology
- Hypertrophy
- Leptin/metabolism
- Leucine/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/metabolism
- Phosphorylation
- Rats
- Rats, Sprague-Dawley
- STAT3 Transcription Factor
- Time Factors
- Trans-Activators/metabolism
- Tyrphostins/pharmacology
- p38 Mitogen-Activated Protein Kinases/metabolism
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Affiliation(s)
- Hye-Jin Shin
- Yonsei Research Institute of Aging Science, Yonsei University, Seoul 120-749, Republic of Korea
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46
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Schäfer K, Halle M, Goeschen C, Dellas C, Pynn M, Loskutoff DJ, Konstantinides S. Leptin promotes vascular remodeling and neointimal growth in mice. Arterioscler Thromb Vasc Biol 2003; 24:112-7. [PMID: 14615386 DOI: 10.1161/01.atv.0000105904.02142.e7] [Citation(s) in RCA: 177] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Human obesity is associated with elevated leptin levels and a high risk of death from cardiovascular disease. In the present study, we investigated the effects of leptin on vascular wound healing and arterial lesion growth in mice. METHODS AND RESULTS Wild-type mice placed on an atherogenic, high-fat diet had elevated (9-fold) leptin levels compared with their counterparts maintained on normal chow, and the former demonstrated significantly enhanced neointimal thickening after carotid artery injury with ferric chloride. The lesions forming in response to injury strongly expressed leptin receptor mRNA and protein. Unexpectedly, the atherogenic diet had no effect on injured vessels from leptin-deficient ob/ob mice despite aggravating obesity, diabetes, and hyperlipidemia in these animals. Daily administration of leptin to ob/ob mice during the 3-week period after injury reversed this phenotype, dramatically increasing neointimal thickness and the severity of luminal stenosis. Exogenous leptin also enhanced lesion growth and increased cellular proliferation in injured arteries from wild-type mice but had no effect on vessels from leptin receptor-deficient db/db mice. CONCLUSIONS Our results raise the possibility that there might be a direct, leptin receptor-mediated link between the hyperleptinemia in human obesity and the increased risk for cardiovascular complications associated with this condition.
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MESH Headings
- Animals
- Aorta/cytology
- Arteriosclerosis/metabolism
- Carotid Arteries/drug effects
- Carotid Arteries/metabolism
- Carotid Arteries/pathology
- Chlorides
- Diet, Atherogenic
- Dietary Fats/adverse effects
- Disease Models, Animal
- Ferric Compounds/toxicity
- Gene Expression Regulation
- Hyperplasia
- Leptin/deficiency
- Leptin/genetics
- Leptin/pharmacology
- Leptin/physiology
- Mice
- Mice, Inbred C57BL
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Obesity/genetics
- Obesity/metabolism
- RNA, Messenger/biosynthesis
- Receptors, Cell Surface/biosynthesis
- Receptors, Cell Surface/deficiency
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/physiology
- Receptors, Leptin
- Recombinant Proteins/pharmacology
- Tunica Intima/pathology
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Affiliation(s)
- Katrin Schäfer
- Department of Cardiology and Pulmonary Medicine, University of Goettingen, Goettingen, Germany
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Maingrette F, Renier G. Leptin increases lipoprotein lipase secretion by macrophages: involvement of oxidative stress and protein kinase C. Diabetes 2003; 52:2121-8. [PMID: 12882931 DOI: 10.2337/diabetes.52.8.2121] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Recent data suggest that plasma leptin may represent a cardiovascular risk factor in diabetic patients. To gain further insight into the role of leptin in atherogenesis associated with diabetes, we investigated in the present study the role of this hormone in the regulation of macrophage lipoprotein lipase (LPL), a proatherogenic cytokine overexpressed in patients with type 2 diabetes. Treatment of human macrophages with leptin (1-10 nmol/l) increased LPL expression, at both the mRNA and protein levels. Pretreatment of these cells with anti-leptin receptor (Ob-R) antibody, protein kinase C (PKC) inhibitors, calphostin C, and GF109203X, or the antioxidant N-acetylcysteine (NAC) blocked the effects of leptin. Similar results were observed in leptin-treated J774 macrophages. In these cells, leptin increased the membrane expression of conventional PKC isoforms and downregulation of endogenous PKC expression abolished the effects of leptin on macrophage LPL expression. In leptin-treated J774 cells, enhanced LPL synthetic rate and increased binding of nuclear proteins to the activated protein-1 (AP-1) consensus sequence of the LPL gene promoter were also observed. This latter effect was abrogated by GF109203X. Overall, these data demonstrate that binding of leptin at the macrophage cell surface increases, through oxidative stress- and PKC-dependent pathways, LPL expression. This effect appears to be exerted at the transcriptional level and to involve AP-1 activation.
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Affiliation(s)
- Fritz Maingrette
- Department of Nutrition, University of Montreal, Montreal, Quebec, Canada
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48
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Margetic S, Gazzola C, Pegg GG, Hill RA. Leptin: a review of its peripheral actions and interactions. Int J Obes (Lond) 2002; 26:1407-33. [PMID: 12439643 DOI: 10.1038/sj.ijo.0802142] [Citation(s) in RCA: 667] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2001] [Revised: 04/02/2002] [Accepted: 05/27/2002] [Indexed: 12/11/2022]
Abstract
Following the discovery of leptin in 1994, the scientific and clinical communities have held great hope that manipulation of the leptin axis may lead to the successful treatment of obesity. This hope is not yet dashed; however the role of the leptin axis is now being shown to be ever more complex than was first envisaged. It is now well established that leptin interacts with pathways in the central nervous system and through direct peripheral mechanisms. In this review, we consider the tissues in which leptin is synthesized and the mechanisms which mediate leptin synthesis, the structure of leptin and the knowledge gained from cloning leptin genes in aiding our understanding of the role of leptin in the periphery. The discoveries of expression of leptin receptor isotypes in a wide range of tissues in the body have encouraged investigation of leptin interactions in the periphery. Many of these interactions appear to be direct, however many are also centrally mediated. Discovery of the relative importance of the centrally mediated and peripheral interactions of leptin under different physiological states and the variations between species is beginning to show the complexity of the leptin axis. Leptin appears to have a range of roles as a growth factor in a range of cell types: as be a mediator of energy expenditure; as a permissive factor for puberty; as a signal of metabolic status and modulation between the foetus and the maternal metabolism; and perhaps importantly in all of these interactions, to also interact with other hormonal mediators and regulators of energy status and metabolism such as insulin, glucagon, the insulin-like growth factors, growth hormone and glucocorticoids. Surely, more interactions are yet to be discovered. Leptin appears to act as an endocrine and a paracrine factor and perhaps also as an autocrine factor. Although the complexity of the leptin axis indicates that it is unlikely that effective treatments for obesity will be simply derived, our improving knowledge and understanding of these complex interactions may point the way to the underlying physiology which predisposes some individuals to apparently unregulated weight gain.
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Affiliation(s)
- S Margetic
- Central Queensland University, School of Chemical and Biomedical Sciences, Queensland, Australia
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49
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Singhal A, Farooqi IS, Cole TJ, O'Rahilly S, Fewtrell M, Kattenhorn M, Lucas A, Deanfield J. Influence of leptin on arterial distensibility: a novel link between obesity and cardiovascular disease? Circulation 2002; 106:1919-24. [PMID: 12370213 DOI: 10.1161/01.cir.0000033219.24717.52] [Citation(s) in RCA: 266] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND The mechanisms by which obesity increases the risk of atherosclerotic cardiovascular disease (CVD) are poorly understood. In experimental models, leptin, a hormone produced by adipose tissue, has been shown adversely to affect vascular health. Therefore, we tested the hypothesis that high leptin concentrations are associated with lower arterial distensibility, an index of circulatory function relevant to the atherosclerotic process. METHODS AND RESULTS Noninvasive, high-resolution, vascular ultrasound was used to measure brachial artery distensibility in 294 healthy adolescents (aged 13 to 16 years) who had a broad range of body mass indexes. Fat mass was measured by bioelectric impedance analysis; fasting serum leptin concentration by radioimmunoassay; and lipid profile, fasting insulin, glucose, and C-reactive protein concentrations by standard laboratory techniques. Higher leptin concentrations were associated with impaired arterial distensibility (regression coefficient, -1.3% change in arterial distension per 10% increase in leptin; 95% CI, -1.9% to -0.8%; P<0.001). This association was independent of fat mass, blood pressure, and C-reactive protein, fasting insulin, or LDL cholesterol concentrations. CONCLUSIONS Elevation in leptin was associated with impaired vascular function, independent of the metabolic and inflammatory disturbances associated with obesity. Our observations are consistent with data from experimental models and suggest that high leptin concentration is an important mechanism for the adverse influence of body fatness on CVD.
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Affiliation(s)
- Atul Singhal
- MRC Childhood Nutrition Research Center, Institute of Child Health, London, UK.
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50
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Parhami F, Tintut Y, Ballard A, Fogelman AM, Demer LL. Leptin enhances the calcification of vascular cells: artery wall as a target of leptin. Circ Res 2001; 88:954-60. [PMID: 11349006 DOI: 10.1161/hh0901.090975] [Citation(s) in RCA: 225] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Leptin, the product of the ob gene, regulates food intake, energy expenditure, and other physiological functions of the peripheral tissues. Leptin receptors have been identified in the hypothalamus and in extrahypothalamic tissues. Increased circulating leptin levels have been correlated with cardiovascular disease, obesity, aging, infection with bacterial lipopolysaccharide, and high-fat diets. All these conditions have also been correlated with increased vascular calcification, a hallmark of atherosclerotic and age-related vascular disease. In addition, the differentiation of marrow osteoprogenitor cells is regulated by leptin. Thus, we hypothesized that leptin may regulate the calcification of vascular cells. In this report, we tested the effects of leptin on a previously characterized subpopulation of vascular cells that undergo osteoblastic differentiation and calcification in vitro. When treated with leptin, these calcifying vascular cells had a significant 5- to 10-fold increase in alkaline phosphatase activity, a marker of osteogenic differentiation of osteoblastic cells. Prolonged treatment with leptin enhanced the calcification of these cells, further supporting the pro-osteogenic differentiation effects of leptin. Furthermore, the presence of the leptin receptor on calcifying vascular cells was demonstrated using reverse transcriptase polymerase chain reaction, immunocytochemistry, and Western blot analysis. We also identified the presence of leptin receptor in the mouse artery wall, localized to subpopulations of medial and adventitial cells, and the expression of leptin by artery wall cells and atherosclerotic lesions in mice. Taken together, these results suggest that leptin regulates the osteoblastic differentiation and calcification of vascular cells and that the artery wall may be an important peripheral tissue target of leptin action.
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MESH Headings
- Alkaline Phosphatase/drug effects
- Alkaline Phosphatase/metabolism
- Animals
- Arteries/drug effects
- Arteries/metabolism
- Arteries/pathology
- Calcinosis/chemically induced
- Calcium/metabolism
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Cattle
- Cells, Cultured
- Female
- Gene Expression Regulation/drug effects
- Immunohistochemistry
- Leptin/metabolism
- Leptin/pharmacology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- RNA/drug effects
- RNA/genetics
- RNA/metabolism
- Receptors, Cell Surface
- Receptors, Leptin
- Reverse Transcriptase Polymerase Chain Reaction
- Vascular Diseases/chemically induced
- Vascular Diseases/metabolism
- Vascular Diseases/pathology
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Affiliation(s)
- F Parhami
- Departments of Medicine, University of California, Los Angeles, USA.
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