Interaction between monocytes and vascular smooth muscle cells induces expression of hepatocyte growth factor.
OBJECTIVE
To investigate the expression of hepatocyte growth factor (HGF)--a multifunctional factor implicated in tissue regeneration, wound healing and angiogenesis--that is induced by cell-to-cell interactions between monocytes and vascular smooth muscle cells (VSMCs), using coculture of human VSMCs and cells of the human monocytoid cell line, THP-1.


METHODS
We collected supernatant from the coculture medium and measured HGF concentrations with an enzyme-linked immunosorbent assay. Northern blot analysis of HGF mRNA was performed using a specific cDNA. To explore which types of cells produce HGF, we performed immunohistochemistry.


RESULTS
Coculture of VSMCs with THP-1 cells for 24 h caused a fivefold increase in HGF concentrations over that in control VSMC culture. Northern blot analysis showed an induction of HGF mRNA in the coculture with a peak at 3 h. Separated cocultures demonstrated that both direct contact and soluble factors contribute to the production of HGF. Immunohistochemistry demonstrated that both types of cells in the coculture produce HGF. Neutralizing antibodies against tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6 inhibited the HGF production in THP-1 cells and VSMCs that was induced by the coculture conditioned medium. The protein kinase C inhibitors H-7, calphostin C and K252b, and the tyrosine kinase inhibitor, genistein, significantly inhibited the production of HGF in the coculture.


CONCLUSIONS
Cell-to-cell interactions between monocytes and VSMCs induced HGF synthesis in both types of cells, suggesting that local HGF production induced by this cell-to-cell interaction has an important role in the pathogenesis of hypertension, atherosclerosis or vascular remodelling.
Okada
M
M
Department of Cardiology, Jichi Medical School, Tochigi, Japan.
Hojo
Y
Y
Ikeda
U
U
Takahashi
M
M
Takizawa
T
T
Morishita
R
R
Shimada
K
K
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002318:Cardiovascular Diseases / Q000209:etiology; D002450:Cell Communication; D002478:Cells, Cultured; D018920:Coculture Techniques; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression; D019833:Genistein / Q000494:pharmacology; D017228:Hepatocyte Growth Factor / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D018836:Inflammation Mediators / Q000037:antagonists & inhibitors / Q000378:metabolism; D007375:Interleukin-1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D009000:Monocytes / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009281:Naphthalenes / Q000494:pharmacology; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000378:metabolism; D000093242:Interleukin-6 Inhibitors
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000911:Antibodies, Monoclonal; D004791:Enzyme Inhibitors; D019833:Genistein; D017228:Hepatocyte Growth Factor; D018836:Inflammation Mediators; D007375:Interleukin-1; D015850:Interleukin-6; D009281:Naphthalenes; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D000093242:Interleukin-6 Inhibitors; C058819:calphostin C