|
|
||||||||
5ß1 Integrin and PI 3-Kinase
1From the Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida; 2Ophthalmology Research, Cedars-Sinai Medical Center, Los Angeles, California; and the 3Department of Pathology, University of Chicago, Chicago, Illinois.
PURPOSE. Extracellular matrix degradation is associated with neovascularization in diabetic retinas. Fibronectin fragments (Fn-fs) are generated during vascular remodeling. The effects of cellular fibronectin (Fn) and selected Fn-fs on adhesion, proliferation, and signal transduction in human retinal endothelial cells (HRECs) were characterized.
METHODS. Relative quantitative RT-PCR, flow cytometry, and immunocytochemistry determined integrin expression on HRECs. Adhesion was evaluated by coating plastic with Fn or Fn-fs of 45, 70, 110, or 120 kDa, and MTT conversion was used to measure proliferation and survival. Peptide inhibitors and blocking antibodies determined adhesive sites and integrins used for adhesion. Pharmacologic inhibitors and Western analyses were used to evaluate intracellular signaling.
RESULTS. HRECs produced significant levels of
2,
3,
5,
v, ß1, ß3, and ß5 integrin subunit mRNA. Flow cytometry of surface integrin expression revealed high levels of
3,
5, and ß1 and lower levels of
1,
v, ß3, and ß5. These results were confirmed by immunocytochemistry. For adhesion to Fn and Fn-fs. the
5ß1 integrin was essential. Pharmacologic inhibitors of PI 3-kinase blocked adhesion to Fn and Fn-fs, whereas the mitogen-activated protein (MAP) kinase kinase (MEK) inhibitor PD98059 blocked phosphorylation. The 110- and 120-kDa Fn-fs showed a concentration-dependent increase in proliferation, whereas 500 ng of the 70 kDa Fn-f-induced proliferation. Addition of III1-C, a matrix assembly domain, increased the proliferative effect of these Fn-fs.
CONCLUSIONS. Fn and its Fn-fs modulate HREC adhesion and proliferation through signal-transduction pathways involving coupling of the
5ß1 integrin through PI 3-kinase. Mitogenic signals for endothelial cells from degraded extracellular matrix may contribute to the development of diabetic retinopathy.
This article has been cited by other articles:
![]() |
J.-Y. Paik, B.-H. Ko, K.-H. Jung, and K.-H. Lee Fibronectin Stimulates Endothelial Cell 18F-FDG Uptake Through Focal Adhesion Kinase-Mediated Phosphatidylinositol 3-Kinase/Akt Signaling J. Nucl. Med., April 1, 2009; 50(4): 618 - 624. [Abstract] [Full Text] [PDF] |
||||
![]() |
Q. Huang and N. Sheibani High glucose promotes retinal endothelial cell migration through activation of Src, PI3K/Akt1/eNOS, and ERKs Am J Physiol Cell Physiol, December 1, 2008; 295(6): C1647 - C1657. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. M. Heikkila, S. Latti, M. J. Leskinen, J. K. Hakala, P. T. Kovanen, and K. A. Lindstedt Activated Mast Cells Induce Endothelial Cell Apoptosis by a Combined Action of Chymase and Tumor Necrosis Factor-{alpha} Arterioscler. Thromb. Vasc. Biol., February 1, 2008; 28(2): 309 - 314. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Zaniolo, M.-E. Gingras, M. Audette, and S. L. Guerin Expression of the Gene Encoding Poly(ADP-ribose) Polymerase-1 Is Modulated by Fibronectin during Corneal Wound Healing. Invest. Ophthalmol. Vis. Sci., October 1, 2006; 47(10): 4199 - 4210. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Economopoulou, K. Bdeir, D. B. Cines, F. Fogt, Y. Bdeir, J. Lubkowski, W. Lu, K. T. Preissner, H.-P. Hammes, and T. Chavakis Inhibition of pathologic retinal neovascularization by {alpha}-defensins Blood, December 1, 2005; 106(12): 3831 - 3838. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Han, J. D. Ritzenthaler, H. N. Rivera, and J. Roman Peroxisome proliferator-activated receptor-{gamma} ligands suppress fibronectin gene expression in human lung carcinoma cells: involvement of both CRE and Sp1 Am J Physiol Lung Cell Mol Physiol, September 1, 2005; 289(3): L419 - L428. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Najmi, R. Korah, R. Chandra, M. Abdellatif, and R. Wieder Flavopiridol Blocks Integrin-Mediated Survival in Dormant Breast Cancer Cells Clin. Cancer Res., March 1, 2005; 11(5): 2038 - 2046. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |