Kinin B1 receptor in adipocytes regulates glucose tolerance and predisposition to obesity

• Published in: PloS one Vol. 7; no. 9; p. e44782
• Main Authors: Mori, Marcelo A, Sales, Vicência Micheline, Motta, Fabiana Louise, Fonseca, Raphael Gomes, Alenina, Natalia, Guadagnini, Dioze, Schadock, Ines, Silva, Elton Dias, Torres, Hugo A M, dos Santos, Edson Lucas, Castro, Charlles Heldan, D'Almeida, Vânia, Andreotti, Sandra, Campaña, Amanda Baron, Sertié, Rogério A L, Saad, Mario J A, Lima, Fabio Bessa, Bader, Michael, Pesquero, João Bosco
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 14-09-2012; Public Library of Science (PLoS)
• Subjects: Adipocytes; Adipocytes - metabolism; Adipose tissue; Animals; Biology; Biophysics; Bradykinin; Bradykinin B1 receptors; Cytokines; Diabetes; Diabetes mellitus; Diabetes mellitus (non-insulin dependent); Gene expression; Gene Expression Regulation; Genetic Predisposition to Disease; Glucose; Glucose - metabolism; Glucose tolerance; Glucose Transporter Type 4 - metabolism; High fat diet; Homeostasis; Insulin; Insulin - metabolism; Insulin resistance; Insulin Resistance - genetics; Kinins; Kinins - metabolism; Male; Medicine; Metabolism; Mice; Mice, Knockout; Obesity; Obesity - genetics; Obesity - metabolism; Pathogenesis; Phenotypes; Physiology; Receptor, Bradykinin B1 - genetics; Receptor, Bradykinin B1 - metabolism; Receptors; Rodents; Sensitivity; Sensitivity analysis; Signaling; Translocation; Weight control; Brazil; Germany
• DOI: 10.1371/journal.pone.0044782
• EISSN: 1932-6203

Kinins participate in the pathophysiology of obesity and type 2 diabetes by mechanisms which are not fully understood. Kinin B(1) receptor knockout mice (B(1) (-/-)) are leaner and exhibit improved insulin sensitivity.
Here we show that kinin B(1) receptors in adipocytes play a role in controlling whole body insulin action and glucose homeostasis. Adipocytes isolated from mouse white adipose tissue (WAT) constitutively express kinin B(1) receptors. In these cells, treatment with the B(1) receptor agonist des-Arg(9)-bradykinin improved insulin signaling, GLUT4 translocation, and glucose uptake. Adipocytes from B(1) (-/-) mice showed reduced GLUT4 expression and impaired glucose uptake at both basal and insulin-stimulated states. To investigate the consequences of these phenomena to whole body metabolism, we generated mice where the expression of the kinin B(1) receptor was limited to cells of the adipose tissue (aP2-B(1)/B(1) (-/-)). Similarly to B(1) (-/-) mice, aP2-B(1)/B(1) (-/-) mice were leaner than wild type controls. However, exclusive expression of the kinin B(1) receptor in adipose tissue completely rescued the improved systemic insulin sensitivity phenotype of B(1) (-/-) mice. Adipose tissue gene expression analysis also revealed that genes involved in insulin signaling were significantly affected by the presence of the kinin B(1) receptor in adipose tissue. In agreement, GLUT4 expression and glucose uptake were increased in fat tissue of aP2-B(1)/B(1) (-/-) when compared to B(1) (-/-) mice. When subjected to high fat diet, aP2-B(1)/B(1) (-/-) mice gained more weight than B(1) (-/-) littermates, becoming as obese as the wild types.
Thus, kinin B(1) receptor participates in the modulation of insulin action in adipocytes, contributing to systemic insulin sensitivity and predisposition to obesity.