Kkh. Lee et al., Hepatocyte growth factor stimulates chemotactic response in mouse embryonic limb myogenic cells in vitro, J EXP ZOOL, 283(2), 1999, pp. 170-180
In this study we investigate the influence of Hepatoctye Growth Factor (HGF
) on the motility of embryonic forelimb myoblasts. Using Blindwell chemotac
tic chambers, it was found that HGF at concentrations of 1-50 ng/ml dramati
cally enhanced the ability of myogenic cells to migrate. This stimulatory e
ffect was elicited in a dose-dependent fashion and the effect was reversed
with the addition of HGF neutralizing antibodies. A checkerboard analysis w
as performed and it revealed that HGF's effect on limb myoblast motility wa
s through both chemokinesis and chemotaxis. HGF was also examined for its a
bility to stimulate myogenic cell proliferation, using MF20 antibody as the
myogenic marker. At all concentrations tested, HGF did not stimulate an ov
erall increase in the numbers of MF20-positive myoblasts in culture. To exa
mine the chemokinetic effect of HGF on cell migration in the limb, cells we
re isolated from the proximal regions of the limb (areas rich in myogenic c
ells), exposed to HGF, labeled with DiI and transplanted into 11.5 day mous
e forelimbs. After 36 h of culture, it was found that DiI-labeled limb cell
s, pretreated with HGF, migrated significantly further in the limb than lab
eled cells that have not been exposed to HGF. The chemotactic effect of HGF
was also investigated by implanting beads loaded with and without HGF into
the 11.5 day limb. Proximal to the beads, DiI-labeled limb cells were also
transplanted. It was found that HGF was able to chemotactically attract an
d direct the migration of DiI-labeled limb cells. Immunohistological staini
ng was performed with HGF antibodies to determine the distribution of HGF i
n the 11.5 day mouse forelimb. It was found that HGF was strongly expressed
by the apical ectodermal ridge (AER), the ectoderm and the mesenchyme dire
ctly beneath the AFR. Positive staining was also obtained for the myogenic
regions. However, the pattern was heterogeneous-punctuated with myogenic ce
lls expressing and not expressing HGF. J. Exp. Zool. 283:170-180, 1999. (C)
1999. Wiley-Liss,Inc.