xenin-25 and Obesity

Xenin-25 is a 25-amino acid peptide hormone co-secreted from the same enteroendocrine K-cell as the incretin peptide glucose-dependent insulinotropic polypeptide. There is no known specific receptor for xenin-25, but studies suggest that at least some biological actions may be mediated through interaction with the neurotensin receptor. Original investigation into the physiological significance of xenin-25 focussed on effects related to gastrointestinal transit and satiety. However, xenin-25 has been demonstrated in pancreatic islets and recently shown to possess actions in relation to the regulation of insulin and glucagon secretion, as well as promoting beta-cell survival. Accordingly, the beneficial impact of xenin-25, and related analogues, has been assessed in animal models of diabetes-obesity. In addition, studies have demonstrated that metabolically active fragment peptides of xenin-25, particularly xenin-8, possess independent therapeutic promise for diabetes, as well as serving as bioactive components for the generation of multi-acting hybrid peptides with antidiabetic potential. This review focuses on continuing developments with xenin compounds in relation to new therapeutic approaches for diabetes-obesity.

Topics: Animals; Diabetes Mellitus, Type 2; Humans; Hypoglycemic Agents; Neurotensin; Obesity; Peptide Fragments; Peptides; Therapies, Investigational

Xenin is a gastrointestinal hormone that reduces food intake when administered centrally and it has been hypothesized that central action of xenin participates in the regulation of whole-body metabolism. The present study was performed to address this hypothesis by investigating the central effect of xenin on the expression of genes and proteins that are involved in the regulation of lipid metabolism in white adipose tissue (WAT). Male obese ob/ob mice received intracerebroventricular (i.c.v.) injections of xenin (5μg) twice 12h apart. Food intake and body weight change during a 24-h period after the first injection were measured. Epididymal WAT was collected at the end of the 24-h treatment period and levels of lipid metabolism-related genes and proteins were measured. Xenin treatment caused significant reductions in food intake and body weight compared to control vehicle treatment. Levels of fatty acid synthase (FASN) protein were significantly reduced by xenin treatment, while levels of adipose triglyceride lipase (Atgl) and beta-3 adrenergic receptor (Adrb3) mRNA and phosphorylated hormone sensitive lipase (Ser

Topics: Adipose Tissue, White; Animals; Body Weight; Eating; Fatty Acid Synthases; Fatty Acids, Nonesterified; Gene Expression; Glycerol; Lipase; Lipid Metabolism; Male; Mice; Neurotensin; Obesity; Phosphorylation; Receptors, Adrenergic, beta-3

Xenin is a peptide of the neurotensin/xenopsin/xenin family secreted from gastric cells and other tissues. The first aim of this study was to investigate the serum xenin and ghrelin levels in obese children and compare the patients with healthy controls. The second aim was to compare the xenin levels in patients with nonalcoholic fatty liver disease (NAFLD) and also with insulin resistance with the patients without these complications.. 62 obese adolescents (27 with NAFLD) and 32 healthy controls were enrolled in the study. Obesity was defined as a body mass index exceeding the 95th percentile for the patients' age and sex. NAFLD was diagnosed via ultrasonographic examination. The insulin resistance was calculated by a homeostasis model assessment (HOMA-IR) index. Serum xenin and ghrelin levels were assessed by enzyme-linked immunosorbent assay.. The mean serum xenin concentration was significantly higher in obese adolescents than the healthy peers (68.15 ± 0.63 vs 16.54 ± 0.07 pg/mL, p = 0.000). Serum xenin levels were not different between the patients with and without NAFLD and also between the patients with and without IR (p > 0.05). There was a positive correlation between xenin levels and relative weight (r = 0.663, p < 0.001) and HOMA-IR (r = 0.612, p < 0.001). Ghrelin was negatively correlated with relative weight (r = -0.283, p < 0.05).. In this study, serum xenin levels of both groups of obese patients were found higher than controls. On the other hand, xenin levels were not different in patients with and without NAFLD. High levels of xenin may be in relation with obesity.

Topics: Adolescent; Biomarkers; Child; Female; Ghrelin; Humans; Insulin Resistance; Male; Neurotensin; Non-alcoholic Fatty Liver Disease; Obesity

Xenin is a newly discovered peptide in humans. The concentration of xenin in human plasma increases after meals and therefore this peptide is considered as a marker of satiety. The mechanism of xenin action in humans has not been thoroughly examined. MEDLINE database contains only few reports about the role of xenin in adults and none of them were performed in children.. The aim of the study was to evaluate the concentration of xenin in children with energy balance disorders.. Plasma xenin concentration was measured in children with inflammatory bowel syndrome (IBD) (n=53; age 14±3 years) before, during and after treatment, obese children (n=26; age 14±2.8 years) during the OGGT test and in healthy children (n=10; age 15.7±2.2 years). Xenin was determined in the plasma using the radioimmunological method.. The mean plasma xenin concentration in the healthy children was 371±36 pg/ml. In the children with an acute phase of IBD the mean concentration of xenin was 367±96 pg/ml and an increase during the treatment to the mean value 399±55 pg/ml was noted. The highest mean value of xenin concentration (412±55 pg/ml) was found during early remission. In obese children, the mean concentration of xenin (198±69 pg/ml) was significantly lower as compared to children with IBD and to control (p<0.001 in both cases). The glucose load did not have any effect on xenin concentration in obese children.. Xenin takes part in the regulation of energy balance in children.

Topics: Adolescent; Blood Glucose; Body Mass Index; Case-Control Studies; Child; Child Nutritional Physiological Phenomena; Chromatography, High Pressure Liquid; Humans; Inflammatory Bowel Diseases; Neurotensin; Obesity; Postprandial Period; Satiety Response