The possible role of adhesion molecule, alpha 3 integrin, in the synthesis of intracrescentic extracellular matrix in accelerated anti-GBM nephritis
Akimoto, H.
Nihon Jinzo Gakkai Shi 42(1): 1-10
2000
ISSN/ISBN: 0385-2385 PMID: 10737007 Document Number: 523846
Studies were performed on the behavior of crescent-composing cells of crescent glomerulonephritis induced by the injection of anti-GBM antibody to WKY rats. alpha 3 integrin, podocalyxin and ED1 were stained immunohistochemically as markers of parietal, visceral epithelial cells, and macrophages, respectively. Cellular fibronectin (cFn) and type I collagen were also stained in the same manner. Fluoresceine- and Rhodamine-conjugated IgGs were used as second antibodies for double staining to show the geographic relation of the two target molecules. Morphological examinations were performed at day 7, 14 and 28 after disease induction. Periodic acid-methenamine-silver (PAM) and Azan staining showed time-dependent increase in extension and cellularity. PAM-positive intracrescentic fibers were likewise increased, which was related to an increased frequency of ruptured capsules. Intracrescentic cFn increasing in parallel with PAM-positive fibers and type I collagen, was remarkably stained at day 28. Intracrescentic ED1-positive cells showed also a significant increase at day 28. Podocalyxin was not stained in the crescent, while ED1 and alpha 3 integrin were remarkably stained. Double staining showed apposition of cFn and alpha 3 integrin, indicating close contact of these molecules, but such apposition was not observed between ED1 and cFn. These findings indicate that ED1 and alpha 3 integrin--(possibly visceral cell derived) positive cells occupy significant cellular components of the crescent and that the latter plays a part in synthesis of the intracrescentic extracellular matrix.