Volume 56, Issue 4, Pages 1242-1246 (October 1999) Extracellular matrix as a determinant of signaling responses in glomerular epithelial cells Andrey V. Cybulsky Kidney International Volume 56, Issue 4, Pages 1242-1246 (October 1999) DOI: 10.1046/j.1523-1755.1999.00699.x Copyright © 1999 International Society of Nephrology Terms and Conditions
Figure 1 Extracellular matrix (ECM) facilitates glomerular epithelial cell (GEC) proliferation (A), EGF-R autophosphorylation (B), and ERK2 (p42) phosphorylation (C). (A) GECs were cultured on collagen I gels or plastic for three days in serum-poor medium with (+) or without (-) EGF. *P < 0.005 vs. other groups; mean ± sem of three culture wells[8]. (B and C) GECs adherent to collagen (C) or plastic (P) were cultured in serum-poor medium for 18 hours and were then incubated with (+) or without (-) EGF (100 ng/ml) for one hour at 37°C. Cell lysates were immunoprecipitated (IP) with anti–EGF-R (B) or anti-ERK antibody (C), and the immunoprecipitates were immunoblotted with antiphosphotyrosine (PY) antibody[11]. Kidney International 1999 56, 1242-1246DOI: (10.1046/j.1523-1755.1999.00699.x) Copyright © 1999 International Society of Nephrology Terms and Conditions
Figure 2 Effect of extracellular matrix (ECM) and anti-β1 Fab (A) or IgG (B) on [3H]-1,2-diacylglycerol ([3H]-DAG)[7]. GECs, labeled with [3H]-arachidonic acid, were plated onto plastic or collagen gels. Medium contained rabbit (Rab) anti-β1 Fab and goat antirabbit IgG (or nonimmune goat IgG). Nonimmune rabbit Fab with goat antirabbit IgG or nonimmune rabbit IgG (at equimolar concentrations to Fab) were added to control incubations (A). (B) Medium contained rabbit anti-β1 IgG or nonimmune IgG in controls. Lipids were extracted after two hours of incubation at 37°C, and [3H]-DAG was separated by thin layer chromatography. Values are mean ± sem of three to six experiments. (A) *P < 0.005, collagen (control) vs. plastic; **P < 0.01, anti-β1 Fab vs. control (collagen). (B) *P < 0.02 anti-β1 IgG vs. control (collagen). Kidney International 1999 56, 1242-1246DOI: (10.1046/j.1523-1755.1999.00699.x) Copyright © 1999 International Society of Nephrology Terms and Conditions
Figure 3 The process of extracellular matrix (ECM) regulation of glomerular epithelial cell (GEC) proliferation. Abbreviations are: EGF, epidermal growth factor; PTPase, phosphotyrosine phosphatase; PLC, phospholipase C; PIP2, phosphatidylinositol-4,5-bisphosphate; EGF-R, epidermal growth factor-receptor; IP3, 1,4,5-trisphosphate; DAG, 1,2-diacylglycerol; PKC, protein kinase C; ERK, extracellular signal-regulated kinase. Kidney International 1999 56, 1242-1246DOI: (10.1046/j.1523-1755.1999.00699.x) Copyright © 1999 International Society of Nephrology Terms and Conditions