Identification and localization of epidermal growth factor and its receptor in the human glomerulus
Yoshioka, K.; Takemura, T.; Murakami, K.; Akano, N.; Matsubara, K.; Aya, N.; Maki, S.
Laboratory Investigation; A Journal of Technical Methods and Pathology 63(2): 189-196
1990
ISSN/ISBN: 0023-6837 PMID: 2199726 Document Number: 362750
The clarify the renal localization of epidermal growth factor (EGF) and EGF-receptor in the kidney tissue, we tried to stain the normal and diseased kidney sections by using immunohistochemical techniques. By indirect immunofluorescence with a monoclonal antibody, EGF was positive in 3 of 5 normal human kidney tissues and in tissues of 24 of 33 patients with proliferative and non-proliferative types of glomerular diseases. Acid-urea treatment of tissue sections to unmask a hidden eptiope of the EGF molecule disclosed EGF immunoreactivity in 4 more kidney specimens (one is normal human kidney and remains are diseased kidney). EGF was localized along the glomerular capillary walls, and also present in the arterioles and small arteries. Staining with two monoclonal antibodies recognizing two different epitopes of EGF-receptor was positive in tissues of two normal subjects and 15 patients with glomerular diseases. EGF-receptor was found along the glomerular capillary walls, in peritubular capillaries, and within the cytoplasm of the epithelial cells of distal tubules and collecting ducts. Immunoelectron microscopy with colloidal gold staining showed that EGF and EGF-receptor were localized in the plasma membrane of glomerular endothelial cells. Immmunofluorescence with or without acid-urea denaturation showed co-expression of EGF and EGF-receptor in glomeruli of one normal subject and 12 patients. This study demonstrated the presence of EGF and EGF-receptors in human glomeruli. There was no obvious difference in EGF and EGF-receptor expression in glomeruli derived from normal or diseased state.