Endothelial activation and increased heparan sulfate expression in cystic fibrosis.

Rationale: Pulmonary disease in cystic fibrosis (CF) is characterized by an exaggerated interleukin (IL)-8-driven, neutrophilic, inflammatory response to infection. Binding of IL-8 to heparan sulfate (HS)-containing proteoglycans (HSPG) facilitates binding of the chemokine to its specific receptor, stabilizes and prolongs IL-8 activity, and protects it from proteolysis. We hypothesized that increased expression of HSPG contributes to the sustained inflammatory response in CF bronchial tissue.

Epithelial expression and release of FGF-2 from heparan sulphate binding sites in bronchial tissue in asthma.

Background: The most characteristic structural change evident in endobronchial biopsies in asthma, even in mild disease, is subepithelial collagen deposition within the lamina reticularis. This has been associated with progressive loss of lung function and the persistence of airway hyperresponsiveness, and has been linked to airway fibroblast proliferation. A potent fibroproliferative factor in bronchoalveolar lavage fluid in asthma is fibroblast growth factor-2 (FGF-2).

Differential effects of EGF and amphiregulin on adhesion molecule expression and migration of colon carcinoma cells.

Epidermal growth factor (EGF) is a potent morphogen affecting cell shape and motility through regulation of adhesive interactions. We have characterized the morphological effects of EGF on GP2d and GP5d colon carcinoma cell lines and have compared the ability of the heparin-binding EGF receptor ligand amphiregulin (AR) to elicit the same effects. EGF induced a marked epithelial-mesenchymal transition in both cell lines.

Two newly established cell lines derived from the same colonic adenocarcinoma exhibit differences in EGF-receptor ligand and adhesion molecule expression.

Two morphologically distinct cell lines, GP2d and GP5d, derived from the same adenocarcinoma of the colon, have been established and characterised. Both clones have the same genetic changes, consistent with the usual pattern of tumour progression in colon cancer. The cells also have an inverted duplication of bands 10q11 to 10q21, but Southern blot analysis failed to identify any translocations involving the ret protooncogene, which maps to this region.

Modulation of the receptor binding affinity of amphiregulin by modification of its carboxyl terminal tail.

Amphiregulin (AR), a heparin-binding, epidermal growth factor (EGF) receptor ligand has homology with EGF but exhibits a lower affinity for the EGF receptor than EGF. As the mature form of AR is truncated at the C terminus and lacks a conserved leucine residue known to be essential for high affinity binding of EGF to the EGF receptor, wild-type AR (AR1-84), a C-terminally extended AR construct incorporating six residues from the predicted coding sequence of AR (AR1-90) and a similarly extended construct with a Met86 to Leu substitution (AR1-90(leu86)) were expressed as recombinant proteins in yeast, purified by heparin affinity and C18 reverse phase chromatography and their relative biological activities determined. The growth factors were tested in mitogenesis and EGF receptor autophosphorylation assays and their relative order of potencies was found to be leu86 > met86 > wt.