Sulfation of extracellular matrices modifies growth factor effects on type II cells on laminin substrata.
The alveolar basement membrane contains a variety of extracellular matrix (ECM) molecules, including laminin and sulfated glycosaminoglycans of proteoglycans. These mixtures exist within microdomains of differing levels of sulfate, which may specifically interact to be key determinants of the known capacity of the type II cell to respond to certain growth factors. Isolated type II cells were exposed to either acidic fibroblast growth factor (FGF-1), basic fibroblast growth factor (FGF-2), or keratinocyte growth factor (KGF; FGF-7) on culture wells precoated with laminin alone or in combination with chondroitin sulfate (CS), high-molecular-weight heparin, or their desulfated forms. Desulfated heparin significantly elevated FGF-1- and FGF-2-stimulated DNA synthesis, whereas desulfated CS and N-desulfated heparin elevated FGF-7-stimulated DNA synthesis by type II cells on laminin substrata. When FGF-1 was mixed into the various test matrix substrata, DNA synthesis was significantly increased in all cases. These results demonstrated that decreased levels of sulfate in ECM substrata act to upregulate responses to heparin-binding growth factors by alveolar epithelial cells on laminin substrata.
Sannes
P L
PL
Department of Anatomy, Physiological Sciences, and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina 27606, USA.
Khosla
J
J
Li
C M
CM
Pagan
I
I
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D002807:Chondroitin / Q000494:pharmacology; D002809:Chondroitin Sulfates / Q000494:pharmacology / Q000502:physiology*; D005109:Extracellular Matrix / Q000502:physiology; D016220:Fibroblast Growth Factor 1; D051526:Fibroblast Growth Factor 10; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors; D006133:Growth Substances / Q000494:pharmacology* / Q000502:physiology; D006493:Heparin / Q000494:pharmacology / Q000502:physiology; D006497:Heparan Sulfate / Q000494:pharmacology / Q000502:physiology*; D007797:Laminin / Q000494:pharmacology / Q000502:physiology*; D011650:Pulmonary Alveoli / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011916:Rats, Inbred F344
D002807:Chondroitin; D002809:Chondroitin Sulfates; D016220:Fibroblast Growth Factor 1; D051526:Fibroblast Growth Factor 10; D016222:Fibroblast Growth Factor 2; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors; D006133:Growth Substances; D006493:Heparin; D006497:Heparan Sulfate; D007797:Laminin; C496455:Fgf7 protein, rat