Heparan sulfate depletion within pulmonary fibroblasts: implications for elastogenesis and repair.
We investigated the role of sulfated proteoglycans in regulating extracellular matrix (ECM) deposition in pulmonary fibroblast cultures. Fibroblast cultures were subject to pharmacologic and enzymatic interventions to modify sulfated proteoglycan levels. Native and proteoglycan-depleted fibroblasts were treated with porcine pancreatic elastase at 2-4-day intervals and the elastase-mediated release of fibroblast growth factor 2 (FGF-2) and glycosaminoglycans was determined. Elastase treatment released significantly less FGF-2 and glycosaminoglycans (GAG) from PG-depleted fibroblasts with respect to native cells. Equilibrium ligand binding studies indicated that 125I FGF-2 binding at both cell surface receptor and heparan sulfate proteoglycan sites was reduced to different extents based on the method of proteoglycan depletion. Quantitation of elastin protein and message levels indicated that biological sulfation is required for the proper incorporation of tropoelastin into the extracellular matrix. These results suggest that sulfated proteoglycans play a central role in modulating pulmonary fibroblast extracellular matrix composition and are important mediators of elastolytic injury.
Department of Biochemistry, Boston University School of Medicine, Massachusetts 02118, USA.
Jo Ann
JA
Buczek-Thomas
Chia L
CL
Chu
Celeste B
CB
Rich
Phillip J
PJ
Stone
Judith A
JA
Foster
Matthew A
MA
Nugent
D000818:Animals; D002478:Cells, Cultured; D004549:Elastin / Q000187:drug effects / Q000502:physiology; D005109:Extracellular Matrix / Q000187:drug effects / Q000502:physiology; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects / Q000502:physiology; D006025:Glycosaminoglycans / Q000378:metabolism; D019812:Heparan Sulfate Proteoglycans / Q000502:physiology; D006497:Heparan Sulfate / Q000502:physiology*; D008168:Lung / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D010196:Pancreatic Elastase / Q000494:pharmacology; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases / Q000502:physiology; D051497:Receptor, Fibroblast Growth Factor, Type 2; D017468:Receptors, Fibroblast Growth Factor / Q000502:physiology; D013552:Swine; D014945:Wound Healing / Q000502:physiology
D004549:Elastin; D016222:Fibroblast Growth Factor 2; D006025:Glycosaminoglycans; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D010196:Pancreatic Elastase; D020794:Receptor Protein-Tyrosine Kinases; D051497:Receptor, Fibroblast Growth Factor, Type 2; D017468:Receptors, Fibroblast Growth Factor; C496356:Fgfr2 protein, rat