Leptin deficiency leads to the regulation of kinin receptors expression in mice.
Kinins are vasoactive and pro-inflammatory peptides generated by the cleavage of the kininogen by kallikreins. Two kinin receptors have been described and denominated B1 and B2. Obesity frequently accompanies other pathologies, such as diabetes and hypertention. The clustering of these pathologies is usually known as "metabolic syndrome". Mice lacking leptin gene (ob/ob) are severely obese and hyperphagic. Using quantitative RT-PCR analysis of B1 and B2 mRNAs expression, we described for the first time a correlation between the kallikrein-kinin system (KKS) and severe obesity in mice. The ob/ob mice presented lower expression of B2 mRNA in the white adipose tissue (WAT) and hypothalamus, both primary sites for neuroendocrine regulation of the energetic metabolism. B1 mRNA, however, is overexpressed in these tissues of ob/ob mice. An upregulation of the B1 mRNA has also been seen in liver, abdominal aorta and stomach fundus. However, different from the lean mice, the expression of the B1 mRNA in brown adipose tissue (BAT) and heart is completely abolished. Our data show that kinin receptors are differently modulated in distinct tissues in obesity. These findings suggest a connection between the KKS and obesity, and suggest that kinin receptors could be involved in the ethiopathogenesis of the metabolic syndrome.
Abe
Karina Camasmie
KC
Department of Biophysics, Federal University of São Paulo, 04023-062, São Paulo, Brazil.
Mori
Marcelo Alves da Silva
MA
Pesquero
Joao Bosco
JB
D052436:Adipose Tissue, White / Q000378:metabolism; D000818:Animals; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D020738:Leptin / Q000172:deficiency / Q000235:genetics* / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008820:Mice, Obese; D009765:Obesity / Q000235:genetics / Q000503:physiopathology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D043783:Receptor, Bradykinin B1 / Q000235:genetics*; D043782:Receptor, Bradykinin B2 / Q000235:genetics*; D054411:Receptors, Leptin; D020133:Reverse Transcriptase Polymerase Chain Reaction
D020738:Leptin; D012333:RNA, Messenger; D043783:Receptor, Bradykinin B1; D043782:Receptor, Bradykinin B2; D054411:Receptors, Leptin; C515447:leptin receptor, mouse