Epidermal growth factor activates EGFR/AMPK signalling to up-regulate the expression of SGLT1 and GLUT2 to promote intestinal glucose absorption in lipopolysaccharide challenged IPEC-J2 cells and piglets

Abstract

Epidermal growth factor (EGF) plays an important role in nutrients transport. The present study was to investigate the effects of EGF on glucose absorption in a cellular injury model (IPEC-J2 cells, in vitro study) and animal injury model (weaned piglets, in vivo study) established by lipopolysaccharide (LPS). In vitro study: porcine intestinal epithelial cells (IPEC-J2) were divided into four treatments: control group (Control); 100 ng/mL EGF treatment group (EGF); 1 μg/mL LPS treatment group (LPS) and 100 ng/mL EGF plus 1 μg/mL LPS treatment group (EGF + LPS). The results showed that EGF significantly increased the alkaline phosphatase (AKP) and sodium/potassium-transporting adenosine triphosphatase (Na+/K+-ATPase) activity, and significantly improved the mRNA and protein expression of SGLT1, GLUT2, EGF receptor (EGFR) and AMP-activated protein kinase α1 (AMPK-α1) in LPS-induced injured cells. In vivo experiment: twenty-four piglets weaned at 21 days were randomly assigned into: (1) control group (basal diets); (2) EGF group (basal diet +2 mg/kg EGF); (3) LPS group (basal diet + injection with 100 μg/kg BW LPS) and (4) EGF + LPS group (basal diet + 2 mg/kg EGF + injection with 100 μg/kg BW LPS). Our results showed that EGF significantly increased the AKP and Na+/K+-ATPase activity, and significantly improved the mRNA expression of SGLT1, GLUT2, EGFR and AMPK-α1 in jejunum mucosa of piglets challenged with LPS. In conclusion, EGF can activate EGFR/AMPK signalling to up-regulate the expression of SGLT1 and GLUT2 as well as improve the AKP and Na+/K+-ATPase activity, thereby promoting intestinal glucose absorption in IPEC-J2 cells and piglets challenged by LPS. HIGHLIGHTS EGF promotes SGLT1 and GLUT2 expression and AKP and Na+/K+-ATPase activity in LPS-induced injured porcine intestinal epithelial cells. EGF promotes SGLT1 and GLUT2 expression and AKP and Na+/K+-ATPase activity in jejunum mucosa of piglets challenged by LPS. Dietary supplementation with EGF activates EGFR/AMPK signalling to up-regulate the expression of SGLT1 and GLUT2 as well as improve the AKP and Na+/K+-ATPase activity to promote intestinal glucose absorption in lipopolysaccharide challenged piglets.