Simultaneous or Delayed Administration of Hepatocyte Growth Factor Equally Represses the Fibrotic Changes in Murine Lung Injury Induced by Bleomycin

Abstract

Hepatocyte growth factor (HGF) is a humoral mediator of epithelial-mesenchymal interactions, acting on a variety of epithelial cells as mitogen, motogen, and morphogen. Exogenous HGF acts as a hepatotrophic factor and a renotrophic factor during experimental injury. To investigate whether HGF has a pulmotrophic function, human recombinant HGF was administered to C57BL/6 mice with severe lung injury by bleomycin (BLM). Low dose simultaneous and continuous administration of HGF (50 micrograms/mouse/7 d) with BLM (100 mg/mouse/7 d) repressed fibrotic morphological changes at 2 and 4 wk. Ashcroft score showed a significant difference in lung fibrosis with and without HGF at 4 wk (3.7 +/- 0.4 versus 4.9 +/- 0.3, p < 0.05). Furthermore, either simultaneous or delayed administration of high dose HGF (280 micrograms/mouse/14 d) equally repressed fibrotic changes by BLM when examined at 4 wk (Ashcroft score: 2.6 +/- 0.4 and 2.4 +/- 0.2 versus 4.1 +/- 0.2, p < 0.01). Hydroxyproline content in the lungs was significantly lower in mice with either simultaneous or delayed administration of high dose HGF as compared to those administered BLM alone (121.8 +/- 8.1% and 113.2 +/- 6.2% versus 162.7 +/- 4.6%, p < 0.001). These findings indicate that exogenous HGF acts as a pulmotrophic factor in vivo and prevents the progression of BLM-induced lung injury when administered in either a simultaneous or delayed fashion. HGF may be a potent candidate to prevent or treat lung fibrosis.

The bleomycin animal model: A useful tool to investigate treatment options for idiopathic pulmonary fibrosis?

“…Similar antifibrotic properties were demonstrated in an animal study, where bleomycin was administered by intraperitoneal infusion from day 0 to day 7, followed by infusion of recombinant HGF from day 7 to day 14, day 14 to day 21, or day 21 to day 28. Fibrosis scores as well as hydroxyproline levels were markedly reduced in the different treatment times, even in the later time points where hydroxyproline levels fell to normal after one week of therapy, implying that recombinant HGF is effective in diminishing fibrotic changes even in established fibrosis (Yaekashiwa et al, 1997) (Mizuno, Matsumoto, Li, & Nakamura, 2005) Most recently BIBF 1000, a selective inhibitor of the group of vascular endothelial growth factor (VEGF), platelet derived growth factor (PDGF) and fibroblast growth factor (FGF) receptor tyrosine kinases, has been tested as an anti-fibrotic agent. These growth factors are known as fibrogenic mediators promoting fibroblast proliferation and matrix contraction.…”

“…Li, Azuma, Takahashi et al, 2002) etc. ), Cytokines (Interferon-β (Azuma, Li et al, 2005), Interferon-γ (Gurujeyalakshmi & Giri, 1995;Hyde, Henderson, Giri, Tyler, & Stovall, 1988;Okada, Sugie, & Aisaka, 1993), Interleukin (IL)-1beta (M. Yasui et al, 1991), IL-10 (Arai et al, 2000), IL-18 (Nakatani-Okuda et al, 2005), Keratinocyte growth factor (Deterding et al, 1997;Sugahara, Iyama, Kuroda, & Sano, 1998;Yi et al, 1996), Hepatocyte growth factor (Dohi, Hasegawa, Yamamoto, & Marshall, 2000;Mizuno, Matsumoto, Li, & Nakamura, 2005;Umeda et al, 2004;Yaekashiwa et al, 1997), Chemokine ligand (CXCL)-10 (Tager et al, 2004),CXCL11 (Burdick et al, 2005), CD (cluster of differentiation)-36 (Yehualaeshet et al, 2000) etc. ), Cytokine antibodies (Transforming growth factor-β (Giri, Hyde, & Hollinger, 1993), Tumor necrosis factor-α (Fichtner-Feigl, Strober, Kawakami, Puri, & Kitani, 2006;Fujita et al, 2003;Piguet & Vesin, 1994), Connective tissue growth factor (Matsuoka et al, 2002), IL-12 , IL-13 (Fichtner-Feigl, Strober, Kawakami, Puri, & Kitani, 2006), Platelet derived growth factor (Aono et al, 2005;Chaudhary, Schnapp, & Park, 2006;Daniels et al, 2004;Yoshida et al, 1999), Vascular endothelial growth factor (Hamada et al, 2005), CCR-1 (Tokuda et al, 2000), CCR-3 (Huaux et al, 2005), CCL-11 (Huaux et al, 2005), CD-11 (Piguet, Rosen, Vesin, & Grau, 1993), MCP-1 etc.…”

“…HGF acts on epithelial cells as a mitogen, stimulating migration and morphogenesis (Dohi, Hasegawa, Yamamoto, & Marshall, 2000;Yaekashiwa et al, 1997). It is described as potent inducer of matrix metalloproteinases (MMPs), which degrade extracellular matrix and are overexpressed during progression of myofibroblast apoptosis (Mizuno, Matsumoto, Li, & Nakamura, 2005).…”

“…Relaxin early (Unemori et al, 1996) 17 9 AG1879 early (Vittal et al, 2005) (Xiao, Zhang, Chen, Feng, & Wang, 2005) 19 1 rHGF early (Yaekashiwa et al, 1997) 19 2 PC-SOD early (Yamazaki et al, 1997) 19 3…”

Hepatocyte growth factor both prevents and ameliorates the symptoms of dermal sclerosis in a mouse model of scleroderma

“…Human HGF cDNA (2.2 kb) was inserted into the NotI sites of the pcDNA3.1(À)vector plasmid under the control of the cytomegalovirus (CMV) enhancerpromoter for a high level of expression. 32 HVJ-liposomes containing HGF DNA plasmid vector or control normal pcDNA3.1(À) plasmid vector were prepared as described previously. 23 Phosphatidylcholine, dioleoyophosphatidylethanolamine, sphingomyelin, phosphatidylserine and cholesterol were mixed in a molar ratio of 13.3:13.3:13.3:10:50 for anionic type HVJ-liposome.…”