Baldassano Sara, Rappa Francesca, Amato Antonella, Cappello Francesco, Mulè Flavia
Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy.
Dipartimento di Biomedicina Sperimentale e Neuroscienze Cliniche, Università di Palermo, Palermo, Italy.
J Cell Physiol. 2015 Dec;230(12):3029-36. doi: 10.1002/jcp.25039.
Glucagon like peptide-2 (GLP-2) is a gastrointestinal hormone released in response to dietary nutrients, which acts through a specific receptor, the GLP-2 receptor (GLP-2R). The physiological effects of GLP-2 are multiple, involving also the intestinal adaptation to high fat diet (HFD). In consideration of the well-known relationship between chronic HFD and impaired glucose metabolism, in the present study we examined if the blocking of the GLP-2 signaling by chronic treatment with the GLP-2R antagonist, GLP-2 (3-33), leads to functional consequences in the regulation of glucose metabolism in HFD-fed mice. Compared with animals fed standard diet (STD), mice at the 10th week of HFD showed hyperglycaemia, glucose intolerance, high plasma insulin level after glucose load, increased pancreas weight and β cell expansion, but not insulin resistance. In HFD fed mice, GLP-2 (3-33) treatment for 4 weeks (from the 6th to the 10th week of diet) did not affect fasting glycaemia, but it significantly increased the glucose intolerance, both fasting and glucose-induced insulin levels, and reduced the sensitivity to insulin leading to insulin-resistance. In GLP-2 (3-33)-treated HFD mice pancreas was significantly heavier and displayed a significant increase in β-cell mass in comparison with vehicle-treated HFD mice. In STD mice, the GLP-2 (3-33) treatment did not affect fasted or glucose-stimulated glycemia, insulin, insulin sensitivity, pancreas weight and beta cell mass. The present study suggests that endogenous GLP-2 may act as a protective factor against the dysregulation of the glucose metabolism that occurs in HFD mice, because GLP-2 (3-33) worsens glucose metabolism disorders.
胰高血糖素样肽-2(GLP-2)是一种胃肠道激素,可响应膳食营养物质而释放,它通过特定受体——GLP-2受体(GLP-2R)发挥作用。GLP-2具有多种生理作用,还涉及肠道对高脂饮食(HFD)的适应性。鉴于慢性HFD与葡萄糖代谢受损之间的已知关系,在本研究中,我们检测了用GLP-2受体拮抗剂GLP-2(3-33)进行慢性治疗来阻断GLP-2信号传导是否会对高脂饮食喂养小鼠的葡萄糖代谢调节产生功能性影响。与喂食标准饮食(STD)的动物相比,高脂饮食第10周的小鼠出现高血糖、葡萄糖不耐受、葡萄糖负荷后血浆胰岛素水平升高、胰腺重量增加和β细胞扩张,但不存在胰岛素抵抗。在高脂饮食喂养的小鼠中,GLP-2(3-33)治疗4周(从饮食第6周到第10周)对空腹血糖没有影响,但显著增加了葡萄糖不耐受、空腹和葡萄糖诱导的胰岛素水平,并降低了对胰岛素的敏感性,导致胰岛素抵抗。与载体处理的高脂饮食小鼠相比,用GLP-2(3-33)处理的高脂饮食小鼠的胰腺明显更重,β细胞量显著增加。在标准饮食小鼠中,GLP-2(3-33)处理对空腹或葡萄糖刺激的血糖、胰岛素、胰岛素敏感性、胰腺重量和β细胞量没有影响。本研究表明,内源性GLP-2可能作为一种保护因子,防止高脂饮食小鼠出现葡萄糖代谢失调,因为GLP-2(3-33)会加剧葡萄糖代谢紊乱。