Sulfation of extracellular matrix substrata modifies responses of
isolated alveolar type ii cells to fibroblast growth factors.
Sannes, Philip L., Jody Khosla, and Pi-Wan Cheng.
Department of Anatomy, Physiological Sciences, and Radiology,
College of Veterinary Medicine, North Carolina State University,
Raleigh, NC; and Department of Biochemistry, University of Nebraska
Medical Center, Omaha, NE
APStracts 3:0096L, 1996.
The pulmonary alveolar basement membrane (BM) associated with alveolar
type II cells has been shown to be significantly less sulfated than
that of type I cells. To examine the biological significance of this
observation, we measured the incorporation of 5-bromodeoxyuridine
(BrdU) as an indicator of DNA synthesis in isolated rat type II cells
cultured for 72-120 hours on substrata that were naturally sulfated,
not sulfated, or chemically desulfated in serum free, hormonally
defined media (SFHD) with and without selected growth factors. The
percentage of cells incorporating BrdU was significantly elevated by
desulfated chondroitin sulfate in the presence of fibroblast growth
factor-2 (FGF-1 or bFGF) and depressed by heparin in the presence of
either fibroblast growth factor-1 (FGF-1 or aFGF) or FGF-2. This
depressive effect was lost by removing sulfate from the heparin. Some
responses were dependent on the period of time in culture, and
concentration and molecular weight of the substrata. These
observations support the notion that sulfation per se of certain
components of BMs is a key determinant of type II cell responses to
select growth factors which may define patterns of proliferation and
differentiation.
Received 15 May 1995; accepted in final form 3 June 1996.
APS Manuscript Number L150-5.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 28 June 96