Search results for " Leptin"
showing 10 items of 56 documents
Plasma leptin and vascular endothelial growth factor (VEGF) in normal subjects at high altitude (5050 m)
2013
Context: High altitude (HA) is a model of severe hypoxia exposure in humans. We hypothesized that nocturnal hypoxemia or acute maximal exercise at HA might affect plasma leptin and VEGF levels. Objectives: Plasma leptin, VEGF and other metabolic variables were studied after nocturnal pulse oximetry and after maximal exercise in healthy lowlanders on the 3rd-4th day of stay in Lobuche (5050 m, HA) and after return to sea level (SL). Results: Leptin was similar at SL or HA in both pre- and post-exercise conditions. Pre-exercise VEGF at HA was lower, and cortisol was higher, than at SL, suggesting that nocturnal intermittent hypoxia associated with periodic breathing at HA might affect these v…
Expression of the obesity hormone leptin and its receptor correlates with hypoxia-inducible factor-1 alpha in human colorectal cancer.
2007
Background: The obesity hormone, leptin, has been found to play a role in development and proliferation of normal and malignant tissues. Leptin activity is mediated through the leptin receptor (ObR) that is often expressed in different human cancer cells. Previously, we found that the expression of leptin and ObR can be stimulated by hypoxia-mimetic agents. The aim of this study was to analyze the abundance of and relationships among leptin, ObR and hypoxia-inducible factor-1α (HIF-1α, transcriptional regulator) in human colorectal cancer. Materials and methods: We investigated the expression of leptin, ObR and HIF-1 a in colorectal cancer specimens from 135 patients who underwent curative …
Leptin and leptin receptor expression in asthma.
2009
Background The adipokine leptin is a potential new mediator for bronchial epithelial homeostasis. Asthma is a chronic inflammatory disease characterized by airway remodeling that might affect disease chronicity and severity. TGF-β is a tissue growth factor the dysregulation of which is associated with airway remodeling. Objective We sought to determine whether a bronchial epithelial dysfunction of the leptin/leptin receptor pathway contributes to asthma pathogenesis and severity. Methods We investigated in vitro the presence of leptin/leptin receptor on human bronchial epithelial cells. Then we studied the effect of TGF-β and fluticasone propionate on leptin receptor expression. Finally, th…
The leptin system during human endometrial receptivity and preimplantation development.
2004
The leptin system is implicated in the regulation of body weight and reproductive function, acting at endocrine and paracrine levels. This ligand-receptor system is mandatory for embryonic implantation in rodents. Here, we investigate the expression pattern of total leptin receptor (OB-R(T)), the long form (OB-R(L)) and short isoforms HuB219.1 and HuB219.3 in the human endometrium. Furthermore, we studied leptin and OB-R(T) mRNA during human embryonic preimplantation development and the embryonic regulation of the endometrial OB-R(L). Leptin receptor expression and its isoforms increase in the luteal phase and peak in the late part. Leptin receptor was localized at the epithelial and glandu…
Insulin resistance in postmenopausal women with metabolic syndrome and the measurements of adiponectin, leptin, resistin, and ghrelin.
2005
Objective: Metabolic syndrome (MBS) is a significant health care problem in postmenopausal women and is driven largely by obesity. We wished to assess the prevalence of insulin resistance (IR), diagnosed using practical methods, and whether several adipocyte factors (adiponectin, leptin, resistin) or the gastric peptide ghrelin, associated with cardiovascular risk, might be abnormal and may relate to IR. Study design: We evaluated 37 obese postmenopausal women with MBS and 34 matched obese premenopausal controls, as well as 14 non-obese premenopausal controls. We measured fasting glucose and insulin, performed 75g 2 hr oral glucose tolerance and intravenous insulin tolerance tests to assess…
Increasing adiposity in normal ovulatory women affects adipocytokine expression in subcutaneous and visceral abdominal fat
2008
Abstract Objective To determine which adipocytokines are differentially expressed as a function of body mass index (BMI), to compare expression of adipocytokines in abdominal subcutaneous and omental fat, and to correlate these findings with serum levels, BMI, and parameters of insulin resistance. Methods Serum and subcutaneous (sc) and omental (om) tissue were obtained from lean and obese ovulatory women undergoing gynecologic surgery. We determined adipocytokine expression in sc versus om abdominal fat and related this to increasing BMI. Results Serum leptin was higher and adiponectin lower in overweight subjects. Adipocytokines had higher expression in sc abdominal versus om adipose tiss…
Human Obesity Reduces the Number of Hepatic Leptin Receptor (Ob-R) Expressing NK Cells
2011
In the industrialized world, obesity is an increasing socioeconomic health problem. Obese subjects have a higher risk of developing several types of cancer. NK cells are an integral component of the innate immune system, able to destruct tumor cells. The adipokine leptin plays a crucial role in the development of obesity and its related diseases. Peripheral leptin signaling is modulated by the liver.The aim of this study was to evaluate the number of hepatic NK cells (CD56+) and the number of leptin-receptor positive (Ob-R+) cells in the livers of five normal-weight and five obese humans. Livers were removed during autopsy and accurately defined sections were stained immunohistochemically a…
Endothelial Leptin Receptor Deletion Promotes Cardiac Autophagy and Angiogenesis Following Pressure Overload by Suppressing Akt/mTOR Signaling.
2019
Background: Cardiac remodeling is modulated by overnutrition or starvation. The adipokine leptin mediates energy balance between adipose tissue and brain. Leptin and its receptors are expressed in the heart. Methods and Results: To examine the importance of endothelial leptin signaling in cardiac hypertrophy, transverse aortic constriction was used in mice with inducible endothelium-specific deletion of leptin receptors (End.LepR-KO) or littermate controls (End.LepR-WT). End.LepR-KO was associated with improved left ventricular function (fractional shortening, 28.4% versus 18.8%; P =0.0114), reduced left ventricular dilation (end-systolic inner left ventricular diameter, 3.59 versus 4.08 m…
The Positive Relationship between Moderate-to-Vigorous Physical Activity and Bone Mineral Content Is Not Mediated by Free Leptin Index in Prepubertal…
2021
Purpose: Moderate-to-vigorous physical activity (MVPA) positively influences bone mineral content (BMC) in prepubertal children, but it is unknown whether this relationship is partially mediated by free leptin index. The aim of this study was to examine whether the relationship between MVPA and total body less head (TBLH) BMC is mediated or moderated by free leptin index in prepubertal children. Methods: We performed a cross-sectional analysis on 401 children (194 girls) from baseline examinations of the Physical Activity and Nutrition in Childhood Study. We applied the four-way decomposition mediation analysis method to assess whether free leptin index, measured from fasted blood samples, …
Apigenin affects leptin/leptin receptor pathway and induces cell apoptosis in lung adenocarcinoma cell line
2011
Abstract Background Apigenin, a common edible plant flavonoid, is a well characterised antioxidant. The adipokine leptin exerts proliferative and anti-apoptotic activities in a variety of cell types. In cancer cells, apigenin may induce a pro-apoptotic pathway whereas leptin has an anti-apoptotic role. The purpose of the study is to investigate the role of apigenin and of leptin/leptin receptor pathway on proliferation and on apoptosis in lung adenocarcinoma. Methods Immunocytochemistry, flow cytometry and RT-q-RT PCR, were used to investigate the expression and modulation of leptin receptors on the lung adenocarcinoma cell line A549 in presence or absence of apigenin and of leptin, alone o…