JCI - Insulin-induced cortical actin remodeling promotes GLUT4 insertion at muscle cell membrane ruffles

Insulin-induced cortical actin remodeling promotes GLUT4 insertion at muscle cell membrane ruffles

Peter Tong, Zayna A. Khayat, Carol Huang, Nish Patel, Atsunori Ueyama, Amira Klip

J Clin Invest. 2001; 108(3):371–381 doi:10.1172/JCI12348

Abstract | Full text | PDF

Options: View larger image (or click on image)

Figure 9

Insulin resistance caused by chronic high glucose and insulin impairs insulin-stimulated, GLUT4 externalization and actin remodeling. L6 GLUT4myc myotubes were maintained in high insulin (100 nM) and high glucose (25 mM) for 24 hours before serum deprivation for 4 hours. Myotubes were then treated with or without 100 nM insulin for 30 minutes (a) or 10 minutes (b–e) at 37°C. (a) Quantification of cell-surface GLUT4myc was performed, as described in Methods. Results are expressed as the fold change relative to basal cells in the untreated control (mean ± SEM of four independently performed experiments). *P < 0.05 compared with respective control in the absence of high insulin/high glucose. (b–e) Cells were fixed and stained for F-actin using Oregon Green-phalloidin as described in Figure 1. Arrows indicate regions of remodeled (c) or partially remodeled (e) actin filaments. The images are representative of four experiments. Scale bar = 50 μm.