ABSTRACT
As the common pathway of chronic renal diseases leading to end-stage renal failure, renal tubulointerstitial fibrosis is characterized by the deposition of extracellular matrix and scar hardening. Our study aimed to construct an in vitro cell culture platform to explore the impact of matrix stiffness on cell morphology and function of renal tubular epithelial cells. Photopolymerized polyacrylamide gels (PAA gel) with varying stiffnesses as model substrates was selected to simulate the matrix stiffness of normal and fibrotic renal tissues with elastic moduli ranging from 1 to 40 kPa. The human renal tubular epithelial cells (HK-2) were seeded on the surface of PAA gels. The impact of matrix stiffness on the morphology of HK-2 were investigated via immunofluorescence staining and confocal microscopy. The expression levels of glucose transporter 1 (GLUT1), glucose transporter 2 (GLUT2), glucose transporter 5 (GLUT5) were semi-quantitatively analyzed. With increasing matrix stiffness, both the levels of GLUT1 and GLUT5 in HK-2 cells were significantly decreased, whereas the expression level and the distribution pattern of GLUT2 in HK-2 remained unchanged with stiffness variation.
ABSTRACT
Aim To investigate the effect of allopurinol and benzbromarone on serum level of uric acid, hepatic xanthine oxidase(XOD) activity and intestinal expression of glucose transporter(GLUT) 2 and 5 in rats with fructose-induced hyperuricemia.Methods Wistar rats were fed with 10% fructose in drinking water for consecutive 8 weeks to induce HUA.Treatment with 5 mg·kg-1 allopurinol or 10 mg·kg-1 benzbromarone were intragastricly administered from 5~8 weeks.Serum level of uric acid and XOD activity in liver were tested.Expression of GLUT2 and GLUT5 in intestine was analyzed by immunohistochemistry staining and Western blot.Results Treatment with allopurinol or benzbromarone significantly decreased the serum level of uric acid in fructose-induced hyperuricemic rats.At the same time, allopurinol treatment significantly reduced the XOD activity in liver and GLUT5 expression in intestine.Nevertheless, benzbromarone treatment did not show inhibitory effect on hepatic XOD activity and intestinal GLUT5 expression.In addition, neither allopurinol nor benzbromarone showed inhibitory effect on GLUT2 expression in intestine.Conclusions Allopurinol decreases serum level of uric acid in fructose-induced hyperuricemic rats.The mechanism is related to reducing XOD-mediated uric acid production in liver, and decreasing GLUT5-mediated fructose absorption in intestine.