Interleukin 4 modulates collagen synthesis by human mesangial cells in a type-specific manner. Nakazato, Yuichi, Hirokazu Okada, Shogo Tajima, Tomoko Hayashida, Yoshihiko Kanno, Hiromichi Suzuki, & Takao Saruta. Health Center, Department of Dermatology, and Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
APStracts 2:0171F, 1995.
Several studies have suggested an involvement of Interleukin 4 (IL-4) in the pathophysiology of glomerulonephritis (GN). To elucidate its possible role in GN, we have investigated the effect of IL-4 on collagen accumulation by human mesangial cells (MC). After incubation with IL-1 and/or IL-4 for 48 h, type I, III, and IV collagens in both soluble and cell-associated forms were identified by Western blotting. IL-1 stimulated type I and IV collagen synthesis, lacking significant effect on type III collagen synthesis. In contrast, IL-4 stimulated type III collagen synthesis without affecting type I and type IV synthesis. ELISA confirmed the dose-dependent effect of IL-4 on collagen type III secretion (2.0-folds at 10 ng/ml). Importantly, IL-1-stimulated type I and IV collagen synthesis was suppressed by concomitant IL-4 treatment. Northern analysis of type I and III procollagen mRNAs displayed consistent results. These data indicate that IL-4 selectively stimulates type III collagen synthesis but also suppresses IL-1-stimulated type I and IV collagen synthesis. Therefore, IL-4 could potentially contribute to the pathological changes in glomerular diseases in co-operate with other cytokines.

Received 7 July 1995; accepted in final form 12 September 1995.
APS Manuscript Number F56-5.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 31 October 95