Activated human neutrophils release hepatocyte growth factor/scatter factor.
BACKGROUND
Hepatocyte growth factor or scatter factor (HGF/SF) is a pleiotropic cytokine that has potent angiogenic properties. We have previously demonstrated that neutrophils (PMN) are directly angiogenic by releasing vascular endothelial growth factor (VEGF). We hypothesized that the acute inflammatory response can stimulate PMN to release HGF.


OBJECTIVE
To examine the effects of inflammatory mediators on PMN HGF release and the effect of recombinant human HGF (rhHGF) on PMN adhesion receptor expression and PMN VEGF release.


METHODS
In the first experiment, PMN were isolated from healthy volunteers and stimulated with tumour necrosis factor-alpha (TNF-alpha), lipopolysaccharide (LPS), interleukin-8 (IL-8), and formyl methionyl-leucyl-phenylalanine (fMLP). Culture supernatants were assayed for HGF using ELISA. In the second experiment, PMN were lysed to measure total HGF release and HGF expression in the PMN was detected by Western immunoblotting. Finally, PMN were stimulated with rhHGF. PMN CD 11a, CD 11b, and CD 18 receptor expression and VEGF release was measured using flow cytometry and ELISA respectively.


RESULTS
TNF-alpha, LPS and fMLP stimulation resulted in significantly increased release of PMN HGF (755+/-216, 484+/-221 and 565+/-278 pg/ml, respectively) compared to controls (118+/-42 pg/ml). IL-8 had no effect. Total HGF release following cell lysis and Western blot suggests that HGF is released from intracellular stores. Recombinant human HGF did not alter PMN adhesion receptor expression and had no effect on PMN VEGF release.


CONCLUSIONS
This study demonstrates that pro-inflammatory mediators can stimulate HGF release from a PMN intracellular store and that activated PMN in addition to secreting VEGF have further angiogenic potential by releasing HGF.
McCourt
M
M
Department of Surgery, Professorial Unit, Cork University Hospital, Cork, Ireland.
Wang
J H
JH
Sookhai
S
S
Redmond
H P
HP
D000704:Analysis of Variance; D015153:Blotting, Western; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D016228:Endothelial Growth Factors / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000187:drug effects; D017228:Hepatocyte Growth Factor / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D016209:Interleukin-8 / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D008222:Lymphokines / Q000378:metabolism*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009389:Neovascularization, Pathologic; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D015815:Cell Adhesion Molecules; D016228:Endothelial Growth Factors; D016209:Interleukin-8; D008070:Lipopolysaccharides; D008222:Lymphokines; D014409:Tumor Necrosis Factor-alpha; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D009240:N-Formylmethionine Leucyl-Phenylalanine; D017228:Hepatocyte Growth Factor