Co-expression by keratinocytes of migration stimulating factor (MSF) and a functional inhibitor of its bioactivity (MSFI).
Migration stimulating factor (MSF) is a potent autocrine and paracrine factor expressed by fibroblasts and epithelial cells in foetal skin, tumours and healing wounds. In tissue culture, MSF bioactivity is present in the conditioned medium of foetal and tumour derived fibroblasts, but not in normal adult fibroblasts or keratinocytes. The conditioned medium of early passage keratinocytes or a keratinocyte line (HaCaT) effectively inhibited the motogenic activity of rhMSF. Fractionation of keratinocyte conditioned medium by size-exclusion chromatography revealed the presence of bioactive MSF as well as a functional inhibitor of MSF (MSFI) in fractions corresponding to approximately 70 kDa and 25 kDa, respectively. MSFI was purified and identified as neutrophil gelatinase-associated lipocalin (NGAL or lipocalin-2). Immunostaining confirmed that keratinocytes expressed both MSF and NGAL, whereas normal adult fibroblasts did not express either. Recombinant and cell-produced NGAL neutralised the motogenic activity of rhMSF. NGAL is known to bind MMP-9 and promote the activity of this protease. In contrast, there was no evidence of NGAL-MSF binding in keratinocyte conditioned medium. MSF displays a number of bioactivities of relevance to cancer progression and wound healing. Our findings indicate a novel function of NGAL and a possible mechanism for regulating MSF activity in tissues.
Jones
Sarah J
SJ
Unit of Cell and Molecular Biology, The Dental School, University of Dundee, Dundee, Scotland.
Florence
Margaret M
MM
Ellis
Ian R
IR
Kankova
Katerina
K
Schor
Seth L
SL
Schor
Ana M
AM
D000209:Acute-Phase Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D005591:Chemical Fractionation; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D017077:Culture Media, Conditioned; D016207:Cytokines / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D003676:Deferoxamine / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005353:Fibronectins; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D000071068:Lipocalin-2; D054834:Lipocalins / Q000302:isolation & purification / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000302:isolation & purification / Q000378:metabolism*
D000209:Acute-Phase Proteins; D017077:Culture Media, Conditioned; D016207:Cytokines; C067625:FN1 protein, human; D005353:Fibronectins; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; D020780:Matrix Metalloproteinase 9; D003676:Deferoxamine