Expression of HGF and IGF-1 during regeneration of masseter muscle in mdx mice.
This study investigated the expression of the growth factors HGF and IGF-1 during the process of muscle regeneration in mdx mice. HGF and IGF-1 are reportedly expressed during the regeneration of muscle tissue in vitro. However, few studies have focused on the role of HGF and IGF-1 during muscle regeneration in mdx mice, which lack expression of the dystrophin gene. In the present study, we examined the expression of HGF and IGF-1 in masseter muscle during muscle regeneration in mdx and B10 (control) mice using histological analysis, immunohistochemistry and Western blotting, as well as examining gene expression by RT-PCR, at 3, 4 and 9 weeks. Mdx mice showed localized HGF and IGF-1 positivity in the cytoplasm of regenerating muscle cells at 3 and 4 weeks, but hardly any reactivity was evident at 9 weeks. The control group was completely negative for IGF-1 at any of the examined time points. Western blotting showed stronger expression of HGF and IGF-1 in mdx mice than in B10 mice at 3 and 4 weeks, but at 9 weeks the expression was absent in both groups. Similar results were obtained using RT-PCR. These present results suggest that HGF and IGF-1 appear to play an important role during regeneration of the masseter muscle in mdx mice.
Department of Anatomy, Tokyo Dental College, 1-2-2 Masago, Mihama-ku, Chiba City, Chiba, 261-8502, Japan.
Hidemitsu
H
Honda
Shinichi
S
Abe
Ryo
R
Ishida
Yutaka
Y
Watanabe
Osamu
O
Iwanuma
Koji
K
Sakiyama
Yoshinobu
Y
Ide
D000818:Animals; D017228:Hepatocyte Growth Factor / Q000096:biosynthesis*; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis*; D008406:Masseter Muscle / Q000378:metabolism*; D051379:Mice; D018101:Mice, Inbred mdx; D012038:Regeneration / Q000502:physiology*; D013997:Time Factors
D017228:Hepatocyte Growth Factor; D007334:Insulin-Like Growth Factor I