Huafang Yu1, Guoxiong Xu, Xiaoming Fan. 1. Department of Gastroenterology, Jinshan Hospital of Fudan University, No. 1508, Longhang Road, Jinshan, Shanghai, 201508, China.
Abstract
BACKGROUND AND AIMS: Recent evidence demonstrates that ghrelin, a short orexigenic peptide from the stomach, has dual effects on cell proliferation in different cell types via autocrine and/or paracrine mechanisms. The aim of this study is to investigate the proliferative role of ghrelin in intestinal epithelial IEC-6 cells and explore underlying mechanism. METHODS: RT-PCR was used for the detection of growth hormone secretagogue receptor 1a. Cell proliferation was measured using Cell Counting Kit-8. Protein expression of ERK 1/2 and Akt was examined using western blotting. Inhibitors of mitogen activated protein kinases kinase and phosphatidylinositol 3-kinase were used to evaluate the role of these signalling pathways in ghrelin-induced proliferation of IEC-6 cells. RESULTS: Growth hormone secretagogue receptor 1a mRNA was present in IEC-6 cells. Ghrelin and des-acyl ghrelin increased IEC-6 cell proliferation in a dose- and time-dependent manner. Ghrelin and des-acyl ghrelin activated ERK1/2, but not Akt. U0126, a specific inhibitor of mitogen activated protein kinases kinase, blocked ghrelin- and des-acyl ghrelin-induced ERK1/2 phosphorylation and cell proliferation in IEC-6 cells. CONCLUSION: Ghrelin and des-acyl ghrelin stimulate the proliferation of IEC-6 cells via the ERK1/2 pathway.
BACKGROUND AND AIMS: Recent evidence demonstrates that ghrelin, a short orexigenic peptide from the stomach, has dual effects on cell proliferation in different cell types via autocrine and/or paracrine mechanisms. The aim of this study is to investigate the proliferative role of ghrelin in intestinal epithelial IEC-6 cells and explore underlying mechanism. METHODS: RT-PCR was used for the detection of growth hormone secretagogue receptor 1a. Cell proliferation was measured using Cell Counting Kit-8. Protein expression of ERK 1/2 and Akt was examined using western blotting. Inhibitors of mitogen activated protein kinases kinase and phosphatidylinositol 3-kinase were used to evaluate the role of these signalling pathways in ghrelin-induced proliferation of IEC-6 cells. RESULTS: Growth hormone secretagogue receptor 1a mRNA was present in IEC-6 cells. Ghrelin and des-acyl ghrelin increased IEC-6 cell proliferation in a dose- and time-dependent manner. Ghrelin and des-acyl ghrelin activated ERK1/2, but not Akt. U0126, a specific inhibitor of mitogen activated protein kinases kinase, blocked ghrelin- and des-acyl ghrelin-induced ERK1/2 phosphorylation and cell proliferation in IEC-6 cells. CONCLUSION:Ghrelin and des-acyl ghrelin stimulate the proliferation of IEC-6 cells via the ERK1/2 pathway.