Macrophage colony stimulating factor expression in human cardiac cells is upregulated by tumor necrosis factor-alpha via an NF-kappaB dependent mechanism.
BACKGROUND
Macrophage colony stimulating factor (M-CSF) is a key factor for monocyte and macrophage survival and proliferation. M-CSF has been implicated in cardiac healing and repair after myocardial infarction.


RESULTS
We show by immunohistochemistry and Western blotting analysis that M-CSF protein is present in human heart tissue. Cultured human adult cardiac myocytes (HACM) and human adult cardiac fibroblasts (HACF) isolated from human myocardial tissue constitutively express M-CSF. When HACM and HACF were treated with tumor necrosis factor-alpha (TNF-alpha) M-CSF protein production and M-CSF mRNA expression, determined by ELISA or by using RT-PCR, respectively, was significantly increased. To determine a possible role of nuclear factor kappaB (NF-kappaB) and activating protein 1 (AP-1) in M-CSF regulation, blockers to both pathways and an adenovirus overexpressing a dominant negative (dn) form of IkappaB kinase 2 (IKK2) were used. Only the NF-kappaB blocker dimethylfumarate and the dn IKK2, but not januskinase inhibitor-1 (JNK-I), were able to block the TNF-alpha-induced increase in M-CSF production in these cells, suggesting that the induction of M-CSF through TNF-alpha is mainly dependent on the activation of the NF-kappaB pathway. The monocyte activation marker CD11b was significantly increased after incubating U937 cells with conditioned medium from HACM or HACF as determined by FACS analysis.


CONCLUSIONS
Our in vitro data taken together with our immunohistochemistry data suggest that human cardiac cells constitutively express M-CSF. This expression of M-CSF in the human heart and its upregulation by TNF-alpha might contribute to monocyte and macrophage survival and differentiation.
Hohensinner
P J
PJ
Department of Internal Medicine II, Medical University of Vienna, Waehringerguertel 18-20, Vienna, Austria.
Kaun
C
C
Rychli
K
K
Niessner
A
A
Pfaffenberger
S
S
Rega
G
G
de Martin
R
R
Maurer
G
G
Ullrich
R
R
Huber
K
K
Wojta
J
J
D015153:Blotting, Western; D039481:CD11b Antigen / Q000378:metabolism; D002469:Cell Separation; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000378:metabolism; D000069462:Dimethyl Fumarate; D004797:Enzyme-Linked Immunosorbent Assay; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism*; D005434:Flow Cytometry; D005650:Fumarates / Q000494:pharmacology; D006801:Humans; D051550:I-kappa B Kinase / Q000235:genetics / Q000378:metabolism; D007150:Immunohistochemistry; D016173:Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000378:metabolism*; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D009154:Mutation; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism*; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D020298:U937 Cells; D015854:Up-Regulation
D039481:CD11b Antigen; D017077:Culture Media, Conditioned; D005650:Fumarates; C509295:ITGAM protein, human; D016328:NF-kappa B; D010446:Peptide Fragments; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; C066650:tumor necrosis factor alpha (36-68); D016173:Macrophage Colony-Stimulating Factor; D051550:I-kappa B Kinase; D000069462:Dimethyl Fumarate