Hepatocyte growth factor ameliorates dermal sclerosis in the tight-skin mouse model of scleroderma

The tight-skin (TSK/+) mouse, a genetic model of systemic sclerosis (SSc), develops cutaneous fibrosis and defects in pulmonary architecture. Because hepatocyte growth factor (HGF) is an important mitogen and morphogen that contributes to the repair process after tissue injury, we investigated the role of HGF in cutaneous fibrosis and pulmonary architecture defects in SSc using TSK/+ mice. TSK/+ mice were injected in the gluteal muscle with either hemagglutinating virus of Japan (HVJ) liposomes containing 8 μg of a human HGF expression vector (HGF-HVJ liposomes) or a mock vector (untreated control). Gene transfer was repeated once weekly for 8 weeks. The effects of HGF gene transfection on the histopathology and expression of tumor growth factor (TGF)-β and IL-4 mRNA in TSK/+ mice were examined. The effect of recombinant HGF on IL-4 production by TSK/+ CD4(+ )T cells stimulated by allogeneic dendritic cells (DCs) in vitro was also examined. Histologic analysis revealed that HGF gene transfection in TSK/+ mice resulted in a marked reduction of hypodermal thickness, including the subcutaneous connective tissue layer. The hypodermal thickness of HGF-treated TSK/+ mice was decreased two-fold to three-fold compared with untreated TSK/+ mice. However, TSK/+ associated defects in pulmonary architecture were unaffected by HGF gene transfection. HGF gene transfection significantly inhibited the expression of IL-4 and TGF-β1 mRNA in the spleen and skin but not in the lung. We also performed a mixed lymphocyte culture and examined the effect of recombinant HGF on the generation of IL-4. Recombinant HGF significantly inhibited IL-4 production in TSK/+ CD4(+ )T cells stimulated by allogeneic DCs. HGF gene transfection inhibited IL-4 and TGF-β mRNA expression, which has been postulated to have a major role in fibrinogenesis and reduced hypodermal thickness, including the subcutaneous connective tissue layer of TSK/+ mice. HGF might represent a novel strategy for the treatment of SSc

Safety and pharmacokinetics of recombinant human hepatocyte growth factor (rh-HGF) in patients with fulminant hepatitis: a phase I/II clinical trial, following preclinical studies to ensure safety

<p>Abstract</p> <p>Background</p> <p>Hepatocyte growth factor (HGF) stimulates hepatocyte proliferation, and also acts as an anti-apoptotic factor. Therefore, HGF is a potential therapeutic agent for treatment of fatal liver diseases. We performed a translational medicine protocol with recombinant human HGF (rh-HGF), including a phase I/II study of patients with fulminant hepatitis (FH) or late-onset hepatic failure (LOHF), in order to examine the safety, pharmacokinetics, and clinical efficacy of this molecule.</p> <p>Methods</p> <p>Potential adverse effects identified through preclinical safety tests with rh-HGF include a decrease in blood pressure (BP) and an increase in urinary excretion of albumin. Therefore, we further investigated the effect of rh-HGF on circulatory status and renal toxicity in preclinical animal studies. In a clinical trial, 20 patients with FH or LOHF were evaluated for participation in this clinical trial, and four patients were enrolled. Subjects received rh-HGF (0.6 mg/m²/day) intravenously for 12 to 14 days.</p> <p>Results</p> <p>We established an infusion method to avoid rapid BP reduction in miniature swine, and confirmed reversibility of renal toxicity in rats. Although administration of rh-HGF moderately decreased BP in the participating subjects, this BP reduction did not require cessation of rh-HGF or any vasopressor therapy; BP returned to resting levels after the completion of rh-HGF infusion. Repeated doses of rh-HGF did not induce renal toxicity, and severe adverse events were not observed. Two patients survived, however, there was no evidence that rh-HGF was effective for the treatment of FH or LOHF.</p> <p>Conclusions</p> <p>Intravenous rh-HGF at a dose of 0.6 mg/m²was well tolerated in patients with FH or LOHF; therefore, it is desirable to conduct further investigations to determine the efficacy of rh-HGF at an increased dose.</p

Hepatocyte growth factor mediates enhanced wound healing responses and resistance to transforming growth factor-β1-driven myofibroblast differentiation in oral mucosal fibroblasts

Oral mucosal wounds are characterized by rapid healing with minimal scarring, partly attributable to the “enhanced” wound healing properties of oral mucosal fibroblasts (OMFs). Hepatocyte growth factor (HGF) is a pleiotropic growth factor, with potential key roles in accelerating healing and preventing fibrosis. HGF can exist as full-length or truncated (HGF-NK), NK1 and NK2 isoforms. As OMFs display elevated HGF expression compared to dermal fibroblasts (DFs), this study investigated the extent to which HGF mediates the preferential cellular functions of OMFs, and the influence of pro-fibrotic, transforming growth factor-β1 (TGF-β1) on these responses. Knockdown of HGF expression in OMFs by short-interfering RNA (siHGF) significantly inhibited OMF proliferative and migratory responses. Supplementation with exogenous TGF-β1 also significantly inhibited proliferation and migration, concomitant with significantly down-regulated HGF expression. In addition, knockdown abrogated OMF resistance to TGF-β1-driven myofibroblast differentiation, as evidenced by increased α-smooth muscle actin (α-SMA) expression, F-actin reorganisation, and stress fibre formation. Responses were unaffected in siHGF-transfected DFs. OMFs expressed significantly higher full-length HGF and NK1 levels compared to patient-matched DFs, whilst NK2 expression was similar in both OMFs and DFs. Furthermore, NK2 was preferentially expressed over NK1 in DFs. TGF-β1 supplementation significantly down-regulated full-length HGF and NK1 expression by OMFs, while NK2 was less affected. This study demonstrates the importance of HGF in mediating “enhanced” OMF cellular function. We also propose that full-length HGF and HGF-NK1 convey desirable wound healing properties, whilst fibroblasts preferentially expressing more HGF-NK2 readily undergo TGF-β1-driven differentiation into myofibroblasts

Regeneración pulmonar en la EPOC mediante administración de LGF: Efecto sobre un modelo animal inducido con CdC12

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Bioquímica. Fecha 11 de Enero de 2012

The Role of Mesenchymal Stromal Cells in Inflammation and Treatment of Pulmonary Fibrosis

The aim of this body of work was to determine the method of action of mesenchymal stromal cell immunomodulation, and their potential benefits in treating pulmonary fibrosis. This was achieved through a series of in vitro studies and an in vivo model of lung disease, namely, bleomycin induced pulmonary fibrosis. Firstly MSC expansion of Treg cells was shown to be dependent on Jagged 1 signalling. MSC inhibition of DC maturation and antigen presentation was shown to also involve Jagged 1 however IL-6 signalling is also necessary. MSC inhibition of DC maturation resulted in a semi mature or “tolerogenic” DC, expressing lower levels of co-stimulatory markers. These cells were capable of suppressing antigen specific T cell proliferation and inducing Treg cells from a naive population. MSC trophic factors were further examined for their ability to promote wound healing. MSC conditioned media cultured with lung epithelial cells encouraged proliferation through the release of the growth factor HGF. MSC CM also reduced the proliferation and activation of primary lung fibroblasts, yet encouraged their migration. These results suggest MSC do not hinder the body’s natural wound healing efforts but prevents unsolicited fibroblast activity and encourages epithelial growth and repair. The positive effects of MSC treatment were further examined in vivo, where MSC were shown to improve pathology in a bleomycin driven model of lung fibrosis. The bleomycin model was examined and refined in order to more accurately represent therapeutic intervention, allowing for investigation of MSC as an anti-fibrotic cell therapy