Search results for "HORMONES"
showing 10 items of 1169 documents
Local Application of Leptin Antagonist Attenuates Angiotensin II–Induced Ascending Aortic Aneurysm and Cardiac Remodeling
2016
Background Ascending thoracic aortic aneurysm ( ATAA ) is driven by angiotensin II (Ang II ) and contributes to the development of left ventricular ( LV ) remodeling through aortoventricular coupling. We previously showed that locally available leptin augments Ang II ‐induced abdominal aortic aneurysms in apolipoprotein E–deficient mice. We hypothesized that locally synthesized leptin mediates Ang II ‐induced ATAA . Methods and Results Following demonstration of leptin synthesis in samples of human ATAA associated with different etiologies, we modeled in situ leptin expression in apolipoprotein E–deficient mice by applying exogenous leptin on the surface of the ascending aorta. This treatm…
Chronic social stress lessens the metabolic effects induced by a high-fat diet
2021
Stress has a major impact on the modulation of metabolism, as previously evidenced by hyperglycemia following chronic social defeat (CSD) stress in mice. Although CSD-triggered metabolic dysregulation might predispose to pre-diabetic conditions, insulin sensitivity remained intact, and obesity did not develop, when animals were fed with a standard diet (SD). Here, we investigated whether a nutritional challenge, a high-fat diet (HFD), aggravates the metabolic phenotype and whether there are particularly sensitive time windows for the negative consequences of HFD exposure. Chronically stressed male mice and controls (CTRL) were kept under (i) SD-conditions, (ii) with HFD commencing post-CSD,…
Genetic variations of leptin and leptin receptor are associated with body composition changes in response to physical training
2010
Leptin regulates body weight, metabolism, and tissue adaptations to environmental stressors. We examined the association of single nucleotide polymorphism (SNP) of leptin promoter G-2548A (rs7799039) and leptin receptor Gln223Arg (rs1137101) with body composition, plasma leptin levels, and peak oxygen uptake (VO(2)peak) in response to 8 weeks of physical training in 48 male military conscripts. AA homozygotes of leptin promoter SNP-2548 showed higher body fat and BMI values than G allele carriers. Acute exercise decreased leptin levels in G allele carriers, but increased in AA homozygotes. Physical training significantly decreased BMI values and also a tendency for decreased plasma leptin l…
Interactions of the hormones leptin, ghrelin, adiponectin, resistin, and PYY3-36 with the reproductive system.
2006
Objective To summarize the effects of novel hormones (leptin, ghrelin, adiponectin, resistin, and PYY3-36) secreted from adipose tissue and the gastrointestinal tract that have been discovered to exert different effects on several reproductive functions, such as the hypothalamic–pituitary–gonadal axis, embryo development, implantation physiology, and clinically relevant conditions. Design A MEDLINE computer search was performed to identify relevant articles. Result(s) Leptin and ghrelin exert important roles on body weight regulation, eating behavior, and reproduction, acting on the central nervous system and target reproductive organs. As a marker of adequate nutritional stores, these horm…
Leptin and the OB-receptor as anti-obesity target: recent in silico advances in the comprehension of the protein-protein interaction and rational dru…
2014
The OB-receptor or leptin receptor (LR) is crucial for energy homeostasis and regulation of food uptake. Leptin is a 16 kDa hormone that is mainly secreted by fat cells into the bloodstream. Under normal circumstances, circulating leptin levels are proportionate to the fat body mass. Sensing of elevated leptin levels by the hypothalamic neuro-circuitry activates a negative feedback loop resulting in reduced food intake and increased energy expenditure. Decreased leptin concentrations lead to opposite effects. Therefore, rational design of leptin agonists/antagonists could be an appealing challenge in the battle against obesity. The Leptin/LR interactions have been studied in several works b…
Expression and immunohistochemical localization of leptin in human periapical granulomas.
2014
Background Leptin, initially described as an adipocyte-derived hormone to regulate weight control, is expressed in normal and inflamed human dental pulp, being up-regulated during pulp experimental inflammation. Leptin receptor (LER) has been identified in human periapical granulomas. The aim of this study was to analyze and characterize the expression of leptin in human periapical granulomas. Material and Methods Fifteen periapical inflammatory lesions were obtained from extracted human teeth and teeth which underwent periapical surgery. After their morphological categorization as periapical granulomas and gradation of the inflammatory infiltrate, they were examined by immunohistochemistry…
Expression of angiogenic regulators, VEGF and leptin, is regulated by the EGF/PI3K/STAT3 pathway in colorectal cancer cells.
2009
Both leptin and vascular endothelial growth factor (VEGF) are growth and angiogenic cytokines that are upregulated in different types of cancer and have been implicated in neoplastic progression. Here we investigated the molecular mechanism by which leptin and VEGF expression are regulated in colon cancer by epidermal growth factor (EGF). In colon cancer cell line HT-29, EGF induced the binding of signal transducer and activator transcription 3 (STAT3) to STAT3 consensus motifs within the VEGF and leptin promoters and stimulated leptin and VEGF mRNA and protein synthesis. All these EGF effects were significantly blocked when HT-29 cells were treated with an inhibitor of the phosphoinositide…
Fluticasone furoate maintains epithelial homeostasis via leptin/leptin receptor pathway in nasal cells
2014
Leptin is involved in the lung epithelial homeostasis. Its role in the nasal tract is largely unknown. Allergic rhinitis (AR) is induced by the allergen exposure leading to consequential structural abnormalities in the nasal epithelium. Topical corticosteroids are recommended as first-line therapy in AR. Parietaria pollen is one of the most important allergenic sources in the southern Europe. In vitro, in human nasal epithelial cell line RPMI 2650, we aimed to determine whether allergen stimulation acts on leptin/leptin receptor pathway and how fluticasone furoate (FF) influences this pathway. The effects of the major allergen recombinant Par j 1 (rPar j 1), of FF, of leptin, and of TGF-b1 …
Insulin-dependent leptin expression in breast cancer cells.
2008
Abstract Pathologic conditions associated with hyperinsulinemia, such as obesity, metabolic syndrome, and diabetes, seem to increase the risk of breast cancer. Here, we studied molecular mechanisms by which insulin activates the expression of leptin, an obesity hormone that has been shown to promote breast cancer progression in an autocrine or paracrine way. Using MDA-MB-231 breast cancer cells, we found that (a) insulin stimulated leptin mRNA and protein expression, which was associated with increased activation of the leptin gene promoter; (b) insulin increased nuclear accumulation of transcription factors hypoxia inducible factor (HIF)-1α and Sp1 and their loading on the leptin promoter;…
Quantitative mass spectrometry for human melanocortin peptides in vitro and in vivo suggests prominent roles for b-MSH and desacetyl a-MSH in energy …
2018
Objective: The lack of pro-opiomelanocortin (POMC)-derived melanocortin peptides results in hypoadrenalism and severe obesity in both humans and rodents that is treatable with synthetic melanocortins. However, there are significant differences in POMC processing between humans and rodents, and little is known about the relative physiological importance of POMC products in the human brain. The aim of this study was to determine which POMC-derived peptides are present in the human brain, to establish their relative concentrations, and to test if their production is dynamically regulated. Methods: We analysed both fresh post-mortem human hypothalamic tissue and hypothalamic neurons derived fro…