A Nanoparticle Delivery of Plasmid Encoding Hepatocyte Growth Factor for Gene Therapy of Silicosis in Mice.

PURPOSE: Silicosis is a serious occupational disease that is characterized by pulmonary infiltrates and fibrosis and is often refractory to current treatments. New therapeutic strategies for silicosis are needed. Hepatocyte growth factor (HGF) is a latent anti-inflammatory and anti-fibrotic growth factor. METHODS: We prepared a polyethyleneimine-polyethylene glycol/pHGF/hyaluronic acid (PEG-PEI/pHGF/HA) nanomaterials loaded with plasmid DNA encoding HGF gene to increase its transfection efficiency. The characterization, including DNA entrapment efficiency, morphology, particle size, and zeta-potential of PEG-PEI/pHGF/HA was studied. And a PEG-PEI/pHGF/HA (N/P=30:1) nanoparticle with low toxicity and high transfection efficiency was used in treatment for silicosis in mice. RESULTS: The results showed that the human HGF expression in the lungs of the mice was increased, and the inflammatory cell infiltration and fibrous collagen deposition was significantly reduced. CONCLUSION: Therefore, PEG-PEI/pHGF/HA nanoparticle warrant further investigation and may be a potential therapeutic strategy for silicosis.

Serum APOA4 Pharmacodynamically Represents Administered Recombinant Human Hepatocyte Growth Factor (E3112).

BACKGROUND: Hepatocyte growth factor (HGF) is an endogenously induced bioactive molecule that has strong anti-apoptotic and tissue repair activities. In this research, we identified APOA4 as a novel pharmacodynamic (PD) marker of the recombinant human HGF (rh-HGF), E3112. METHODS: rh-HGF was administered to mice, and their livers were investigated for the PD marker. Candidates were identified from soluble proteins and validated by using human hepatocytes in vitro and an animal disease model in vivo, in which its c-Met dependency was also ensured. RESULTS: Among the genes induced or highly enhanced after rh-HGF exposure in vivo, a soluble apolipoprotein, Apoa4, was found to be induced by rh-HGF in the murine liver. By using primary cultured human hepatocytes, the significant induction of human APOA4 was observed at the mRNA and protein levels, and it was inhibited in the presence of a c-Met inhibitor. Although mice constitutively expressed Apoa4 mRNA in the small intestine and the liver, the liver was the primary organ affected by administered rh-HGF to strongly induce APOA4 in a dose- and c-Met-dependent manner. Serum APOA4 levels were increased after rh-HGF administration, not only in normal mice but also in anti-Fas-induced murine acute liver failure (ALF), which confirmed the pharmacodynamic nature of APOA4. CONCLUSIONS: APOA4 was identified as a soluble PD marker of rh-HGF with c-Met dependency. It should be worthwhile to clinically validate its utility through clinical trials with healthy subjects and ALF patients.

Traction and attraction: haptotaxis substrates collagen and fibronectin interact with chemotaxis by HGF to regulate myoblast migration in a microfluidic device.

Cell migration is central to development, wound healing, tissue regeneration, and immunity. Despite extensive knowledge of muscle regeneration, myoblast migration during regeneration is not well understood. C2C12 mouse myoblast migration and morphology were investigated using a triple-docking polydimethylsiloxane-based microfluidic device in which cells moved under gravity-driven laminar flow on uniform (=) collagen (CN=), fibronectin (FN=), or opposing gradients (CN-FN or FN-CN). In haptotaxis experiments, migration was faster on FN= than on CN=. At 10 h, cells were more elongated on FN-CN and migration was faster than on the CN-FN substrate. Net migration distance on FN-CN at 10 h was greater than on CN-FN, as cells rapidly entered the channel as a larger population (bulk-cell movement, wave 1). Hepatocyte growth factor (HGF) stimulated rapid chemotaxis on FN= but not CN=, increasing migration speed at 10 h early in the channel at low HGF in a steep HGF gradient. HGF accelerated migration on FN= and bulk-cell movement on both uniform substrates. An HGF gradient also slowed cells in wave 2 moving on FN-CN, not CN-FN. Both opposing-gradient substrates affected the shape, speed, and net distance of migrating cells. Gradient and uniform configurations of HGF and substrate differentially influenced migration behavior. Therefore, haptotaxis substrate configuration potently modifies myoblast chemotaxis by HGF. Innovative microfluidic experiments advance our understanding of intricate complexities of myoblast migration. Findings can be leveraged to engineer muscle-tissue volumes for transplantation after serious injury. New analytical approaches may generate broader insights into cell migration.

HGF alleviates septic endothelial injury by inhibiting pyroptosis via the mTOR signalling pathway.

BACKGROUND: Endothelial injury is one of the predominant pathophysiological characteristics of sepsis and is the major cause of sepsis-induced multiple organ failure. Endothelial pyroptosis is a fatal mechanism of endothelial injury in sepsis, and specific, effective therapies are lacking. Although hepatocyte growth factor (HGF) has been shown to have anti-apoptotic and anti-necrotic effects, whether it prevents pyroptosis to improve endothelial injury in sepsis remains unclear. METHODS: Recombinant HGF was intravenously injected into mice with sepsis caused by caecal ligation puncture (CLP). Histopathological examination and transmission electron microscopy (TEM) were used to measure lung vascular endothelial injury. Lipopolysaccharide (LPS) was transfected into EA.hy926 cells to induce endothelial pyroptosis, and the cells were treated with HGF in the presence of inhibitors of c-Met and mTOR, namely, PHA-665752 and rapamycin, respectively. The mTOR signalling pathway and mitochondrial physiology were assessed using Western blot and flow cytometry. RESULTS: Intravenous HGF effectively alleviated pulmonary vascular endothelial injury and acute lung injury in the septic mice. The TEM results of lung tissue revealed that HGF attenuated pulmonary vascular endothelial pyroptosis, which was confirmed in vitro. Transfected LPS induced the pyroptosis of EA.hy926 cells and damaged their paracellular permeability, and these effects were ameliorated by treating the cells with recombinant HGF. The protective effect of HGF against pyroptosis was dependent on c-Met/mTOR signalling. mTOR activation effectively protected mitochondrial physiology and decreased reactive oxygen species (ROS) production in EA.hy926 cells in vitro. CONCLUSIONS: These results demonstrated that HGF protected mitochondrial physiology by activating mTOR signalling to partially ameliorate endothelial pyroptosis and attenuate vascular endothelial injury and acute lung injury in sepsis animal model.

A Randomized, Double-Blind, Placebo-Controlled Phase II Study of Hepatocyte Growth Factor in the Treatment of Critical Limb Ischemia.

NL003 is a plasmid engineered to simultaneously express two isoforms of hepatocyte growth factor. This phase II study was performed to assess the clinical safety and efficacy of intramuscular injection of NL003 in critical limb ischemia (CLI) patients for 6 months. Two hundred patients (Rutherford scale 4-5) were randomly assigned: placebo (n = 50), low-dose NL003 (n = 50), middle-dose NL003 (n = 50), or high-dose NL003 (n = 50). The drug was administered in the affected limb of 197 patients on days 0, 14, and 28. No significant differences in the incidence of adverse events (AEs) or serious AEs were found among the groups. At 6 months, pain severity was significantly reduced in all NL003 groups, but not in the placebo group (p < 0.05). The proportion of patients with complete ulcer healing in the high-dose group was significantly higher than that of the placebo group (p = 0.0095). There were no statistically significant differences in transcutaneous oxygen pressure (TcPO2), ankle-brachial index (ABI), or toe-brachial index (TBI) value among the four groups throughout the study period. These results provide the first effective evidence of significant improvements in total healing of ulcers in treated legs, complete pain relief without analgesics, and safety for NL003 in patients with Rutherford stage 4-5.

Application of Hepatocyte Growth Factor for Acute Spinal Cord Injury: The Road from Basic Studies to Human Treatment.

Hepatocyte growth factor (HGF) was first identified as a potent mitogen for mature hepatocytes, and has also gained attention as a strong neurotrophic factor in the central nervous system. We found that during the acute phase of spinal cord injury (SCI) in rats, c-Met, the specific receptor for HGF, increases sharply, while the endogenous HGF up-regulation is relatively weak. Introducing exogenous HGF into the spinal cord by injecting an HGF-expressing viral vector significantly increased the neuron and oligodendrocyte survival, angiogenesis, and axonal regeneration, to reduce the area of damage and to promote functional recovery in rats after SCI. Other recent studies in rodents have shown that exogenously administered HGF during the acute phase of SCI reduces astrocyte activation to decrease glial scar formation, and exerts anti-inflammatory effects to reduce leukocyte infiltration. We also reported that the intrathecal infusion of recombinant human HGF (intrathecal rhHGF) improves neurological hand function after cervical contusive SCI in the common marmoset, a non-human primate. Based on these collective results, we conducted a phase I/II clinical trial of intrathecal rhHGF for patients with acute cervical SCI who showed a modified Frankel grade of A/B1/B2 72 h after injury onset, from June 2014 to May 2018.

Efficacy of the dual controlled release of HGF and bFGF impregnated with a collagen/gelatin scaffold.

BACKGROUND: We previously developed collagen/gelatin sponges (CGS) able to sustain and release basic fibroblast growth factor (bFGF) and reported that this CGS impregnated with bFGF promoted dermis-like tissue formation. We herein confirmed the single-sustained release of hepatocyte growth factor (HGF) and the dual sustained release of HGF and bFGF from CGSs, and explored its efficacy using a murine model of skin defects. MATERIALS AND METHODS: The sustained release of HGF alone and both HGF and bFGF from CGSs were evaluated in vitro. CGSs (8 mm in diameter) impregnated with normal saline solution (NSS) (NSS group), HGF solution (10 or 50 µg/cm2) (HGF-L or HGF-H group), bFGF solution (7 µg/cm2) (bFGF group), or HGF (10 µg/cm2) and bFGF (7 µg/cm2) solution (HGF + bFGF group) were implanted into full-thickness skin defects on the backs of mice. The wound area, neoepithelium length, dermis-like tissue formation and newly formed capillaries were evaluated. RESULTS: The single release of HGF and the dual release of HGF and bFGF from CGSs were confirmed. At week 1, the wound closure and neoepithelium length were promoted in the HGF-L group compared with the NSS group. At week 2, the wound closure, neoepithelium length, dermis-like tissue formation and newly formed capillary formation were promoted in the bFGF and HGF + bFGF groups compared with the NSS and HGF-H groups. Newly formed capillary formation was superior in the HGF + bFGF group compared with the bFGF group. CONCLUSIONS: The dual release of HGF and bFGF from CGS was a promising treatment for full-thickness skin defects.

A novel protein-engineered hepatocyte growth factor analog released via a shear-thinning injectable hydrogel enhances post-infarction ventricular function.

In the last decade, numerous growth factors and biomaterials have been explored for the treatment of myocardial infarction (MI). While pre-clinical studies have demonstrated promising results, clinical trials have been disappointing and inconsistent, likely due to poor translatability. In the present study, we investigate a potential myocardial regenerative therapy consisting of a protein-engineered dimeric fragment of hepatocyte growth factor (HGFdf) encapsulated in a shear-thinning, self-healing, bioengineered hydrogel (SHIELD). We hypothesized that SHIELD would facilitate targeted, sustained intramyocardial delivery of HGFdf thereby attenuating myocardial injury and post-infarction remodeling. Adult male Wistar rats (n = 45) underwent sham surgery or induction of MI followed by injection of phosphate buffered saline (PBS), 10 µg HGFdf alone, SHIELD alone, or SHIELD encapsulating 10 µg HGFdf. Ventricular function, infarct size, and angiogenic response were assessed 4 weeks post-infarction. Treatment with SHIELD + HGFdf significantly reduced infarct size and increased both ejection fraction and borderzone arteriole density compared to the controls. Thus, sustained delivery of HGFdf via SHIELD limits post-infarction adverse ventricular remodeling by increasing angiogenesis and reducing fibrosis. Encapsulation of HGFdf in SHIELD improves clinical translatability by enabling minimally-invasive delivery and subsequent retention and sustained administration of this novel, potent angiogenic protein analog. Biotechnol. Bioeng. 2017;114: 2379-2389. © 2017 Wiley Periodicals, Inc.

Poly (Ethylene Glycol)-Block-Brush Poly (L-Lysine) Copolymer as an Efficient Nanocarrier for Human Hepatocyte Growth Factor with Enhanced Bioavailability and Anti-Ischemia Reperfusion Injury Efficacy.

BACKGROUND/AIMS: The aim of this study was to assess the effect of human hepatocyte growth factor (hHGF)-loaded poly (ethylene glycol)-b-brush poly (l-lysine) (PEG-b-P(ELG-g-PLL)) copolymer on ischemia/reperfusion (I/R) injury to different organs. METHODS: The isoelectric point (pI) of hHGF is 5.5, and hHGF combined with PEG-b-P(ELG-g-PLL) copolymer via electrostatic interactions at pH 7.4. The synthesized PEG-b-P(ELG-g-PLL) copolymer was analyzed using 1H nuclear magnetic resonance (1H NMR) and gel permeation chromatography (GPC). The hHGF/PEG-b-P(ELG-g-PLL) complex was evaluated using a nanoparticle size instrument and transmission electron microscopy (TEM). In addition, vivo performance of hHGF/PEG-b-P(ELG-g-PLL) complex was evaluated using plasma hHGF concentration and different organs ischemia reperfusion injury in rats. RESULTS: An in vitro investigation showed that PEG-b-P(ELG-g-PLL) could serve as a potential hHGF nanocarrier with efficient encapsulation and sustained release. An additional in vivo investigation revealed that the hHGF/PEG-b-P(ELG-g-PLL) complex could prolong increases in plasma hHGF concentration and protect different organs (the brain, heart and kidney) against I/R injury. CONCLUSION: Poly (ethylene glycol)-block-brush poly (l-lysine) copolymer as an efficient nanocarrier for human hepatocyte growth factor with enhanced bioavailability and anti-ischemia reperfusion injury efficacy.

Perioperative hepatocyte growth factor (HGF) infusions improve hepatic regeneration following portal branch ligation (PBL) in rodents.

BACKGROUND: As hepatic surgery has become safer and more commonly performed, the extent of hepatic resections has increased. When there is not enough expected hepatic reserve to facilitate primary resection of hepatic tumors, a clinical adjunct to facilitating primary resection is portal vein embolization (PVE). PVE allows the hepatic remnant to increase to an appropriate size prior to resection via hepatocyte regeneration; however, PVE is not always successful in facilitating adequate regeneration. One of the strongest trophic factors for hepatocyte regeneration is hepatocyte growth factor (HGF). The purpose of this study was to improve hepatic regeneration with perioperative HGF infusions in an animal model that mimics PVE. METHODS: Portal branch ligation (PBL) in rodents is equivalent to PVE in humans. We performed left-sided PBL in Sprague-Dawley rodents with the experimental group receiving perioperative HGF infusions. Baseline and postoperative liver volumetrics were obtained with CT scanning methods as performed in clinical practice. Baseline and postoperative liver functions were assessed via indocyanine green (ICG) elimination testing. RESULTS: HGF infused rodents had statistically significant increase in all postoperative liver volumetrics. Most clinically relevant were increased right liver volumes (RLV), 14.10 versus 7.85 cm3 (p value 0.0001), and increased degree of hypertrophy (DH %), 159.23 versus 47.11 % (p value 0.0079). HGF infused rodents also had a quick return to baseline liver function, 2.38 days compared to 6.13 days (p value 0.0001). CONCLUSION: Perioperative HGF infusions significantly increase hepatic regeneration following PBL in rodents. Perioperative HGF infusions following PVE are a possible adjunct to increase the amount of patients able to successfully undergo primary resection for hepatic tumors. Further basic science is warranted in examining the use of HGF infusions to increase hepatic regeneration and translating that basic science work to clinical practice.

Treatment of Femoral Head Necrosis With Bone Marrow Mesenchymal Stem Cells Expressing Inducible Hepatocyte Growth Factor.

Our study assessed the effect of bone marrow mesenchymal stem cells (BMSCs) expressing inducible hepatocyte growth factor (HGF) on the recovery of femoral head necrosis (FHN). BMSCs were isolated by density gradient centrifugation. A recombinant AdTRE-HGF was constructed as the response plasmid and Adeno-X Tet-on as the regulator vector. The regulator and the response vectors were coinfected into BMSCs and induced at 0, 200, 500, 1000, and 1200 ng/mL doxycycline (Dox). After 3 days, the concentration of HGF was determined using enzyme-linked immunosorbent assay. Forty rabbits were selected to establish the FHN model and divided into 4 experimental groups. After the rabbits were killed by ketamine overdose, the restoration of FHN was assessed. The distribution of HGF-positive cells was observed by immunohistochemical method. Enzyme-linked immunosorbent assay results showed that 1000 ng/mL Dox induced the highest HGF expression level, even higher than the 1200 ng/mL Dox induction. The highest osteonecrosis incidence and empty lacunae percentage were found in group A compared with all the other groups (all P < 0.05). Furthermore, dramatically lower osteonecrosis incidence and empty lacunae percentage were found in group C compared with those of groups B and D (all P < 0.05). A significantly higher level of HGF protein was detected in group C compared with the other groups (all P < 0.05). Our study successfully developed the AdTRE-HGF, a recombinant adenovirus carrying HGF gene, for high expression of HGF in BMSCs. Importantly, introduction of BMSCs expressing HGF successfully produced the desired therapeutic effect in reversing FHN, in a Dox-dependent manner.

Rescuing Impaired Re-endothelialization of Drug-Eluting Stents Using the Hepatocyte Growth Factor.

BACKGROUND: Current commercially available drug-eluting stents (DESs) are criticized for the problem of stent thrombosis by induced impaired re-endothelialization (RE). The solving of this challenge could be boosted by endothelial progenitor cells (EPCs). The purpose of this study was to examine the effects of hepatocyte growth factor (HGF) on this process. METHODS: The abundance and functional capacity of circulating EPC was analyzed by a fluorescence-activated cell sorter and western blot. The in vivo effect of HGF on DES patency, RE, and neointimal formation was investigated in a hypercholesterolemic rabbit model. RESULTS: After 7 days of HGF administration, the number of CD34+/CD133+ progenitor cells had increased significantly. HGF also significantly inhibited the onset of senescence of EPC due to a decrease in protein expression of p53 and p21. In the in vivo study, HGF-treated DES had a higher patency rate than the control group (11/12 vs. 6/12, P = 0.032). Moreover, the HGF-treated group exhibited better RE (control group: 69.5 ± 12.9%, HGF group: 88.8 ± 8.4%, P = 0.006), but significantly smaller areas of neointima (control group: 0.68 ± 0.15 mm2, HGF group: 0.45 ± 0.18 mm2, P = 0.02). CONCLUSION: HGF efficiently ameliorates the vascular response to stent implantation, and has an important redeeming influence on the deleterious endothelial effects of DES.

Conversion of non-adipogenic fibroblasts into adipocytes by a defined hormone mixture.

Obesity is accompanied by an increase in the size and the number of adipocytes. As adipocytes are thought to differentiate from pre-adipocytes, we postulate that non-adipogenic fibroblasts contribute to adipocyte formation under certain conditions such as obesity. We report for the first time that NIH-3T3 fibroblasts, which are generally considered to be non-adipogenic, can be converted into mature adipocytes by treatment with a defined hormone mixture comprising EGF (epidermal growth factor), HGF (hepatocyte growth factor), Dex (dexamethasone) and insulin. Furthermore, NIH-3T3 cells transplanted into obese immunodeficient NOD/SCID (non-obese diabetic/severe combined immunodeficient) mice formed adipocytes in vivo. Interestingly, the mixture elicited conversion of NIH-3T3 cells directly into adipocytes without a preceding pre-adipocyte stage. Functional analysis revealed that each component of the mixture was necessary for the induction of adipogenesis, including Dex which inhibited the cell proliferation stimulated by EGF. Upon profiling the signalling pathways employed by EGF and HGF, we found STAT5 (signal transducer and activator of transcription 5) signalling to be activated, predominantly at the levels of both transcription and post-translational modification. Inhibition of the STAT5 pathway, either by genetic knockdown or a specific pharmacological agent, blocked adipogenesis in NIH-3T3 cells. Taken together, these data not only establish a newly recognized grouping of factors that can induce trans-differentiation of non-adipogenic fibroblasts into adipocytes, but also give us a greater understanding of obesity.

Hepatocyte growth factor, a determinant of airspace homeostasis in the murine lung.

The alveolar compartment, the fundamental gas exchange unit in the lung, is critical for tissue oxygenation and viability. We explored hepatocyte growth factor (HGF), a pleiotrophic cytokine that promotes epithelial proliferation, morphogenesis, migration, and resistance to apoptosis, as a candidate mediator of alveolar formation and regeneration. Mice deficient in the expression of the HGF receptor Met in lung epithelial cells demonstrated impaired airspace formation marked by a reduction in alveolar epithelial cell abundance and survival, truncation of the pulmonary vascular bed, and enhanced oxidative stress. Administration of recombinant HGF to tight-skin mice, an established genetic emphysema model, attenuated airspace enlargement and reduced oxidative stress. Repair in the TSK/+ mouse was punctuated by enhanced akt and stat3 activation. HGF treatment of an alveolar epithelial cell line not only induced proliferation and scattering of the cells but also conferred protection against staurosporine-induced apoptosis, properties critical for alveolar septation. HGF promoted cell survival was attenuated by akt inhibition. Primary alveolar epithelial cells treated with HGF showed improved survival and enhanced antioxidant production. In conclusion, using both loss-of-function and gain-of-function maneuvers, we show that HGF signaling is necessary for alveolar homeostasis in the developing lung and that augmentation of HGF signaling can improve airspace morphology in murine emphysema. Our studies converge on prosurvival signaling and antioxidant protection as critical pathways in HGF-mediated airspace maintenance or repair. These findings support the exploration of HGF signaling enhancement for diseases of the airspace.

Perfusable branching microvessel bed for vascularization of engineered tissues.

Vascularization is critical for the survival of engineered tissues in vitro and in vivo. In vivo, angiogenesis involves endothelial cell proliferation and sprouting followed by connection of extended cellular processes and subsequent lumen propagation through vacuole fusion. We mimicked this process in engineering an organized capillary network anchored by an artery and a vein. The network was generated by inducing directed capillary sprouting from vascular explants on micropatterned substrates containing thymosin ß4-hydrogel. The capillary outgrowths connected between the parent explants by day 21, a process that was accelerated to 14 d by application of soluble VEGF and hepatocyte growth factor. Confocal microscopy and transmission electron microscopy indicated the presence of tubules with lumens formed by endothelial cells expressing CD31, VE-cadherin, and von Willebrand factor. Cardiac tissues engineered around the resulting vasculature exhibited improved functional properties, cell striations, and cell-cell junctions compared with tissues without prevascularization. This approach uniquely allows easy removal of the vasculature from the microfabricated substrate and easy seeding of the tissue specific cell types in the parenchymal space.

Amniotic fluid-borne hepatocyte growth factor protects rat pups against experimental necrotizing enterocolitis.

Fetal swallowing of amniotic fluid, which contains numerous cytokines and growth factors, plays a key role in gut mucosal development. Preterm birth interrupts this exposure to amniotic fluid-borne growth factors, possibly contributing to the increased risk of necrotizing enterocolitis (NEC) in premature infants. We hypothesized that supplementation of formula feeds with amniotic fluid can provide amniotic fluid-borne growth factors and prevent experimental NEC in rat pups. We compared NEC-like injury in rat pups fed with infant formula vs. formula supplemented either with 30% amniotic fluid or recombinant hepatocyte growth factor (HGF). Cytokines/growth factors in amniotic fluid were measured by immunoassays. Amniotic fluid and HGF effects on enterocyte migration, proliferation, and survival were measured in cultured IEC6 intestinal epithelial cells. Finally, we used an antibody array to investigate receptor tyrosine kinase (RTK) activation and immunoblots to measure phosphoinositide 3-kinase (PI3K) signaling. Amniotic fluid supplementation in oral feeds protected rat pups against NEC-like injury. HGF was the most abundant growth factor in rat amniotic fluid in our panel of analytes. Amniotic fluid increased cell migration, proliferation, and cell survival in vitro. These effects were reproduced by HGF and blocked by anti-HGF antibody or a PI3K inhibitor. HGF transactivated several RTKs in IEC6 cells, indicating that its effects extended to multiple signaling pathways. Finally, similar to amniotic fluid, recombinant HGF also reduced the frequency and severity of NEC-like injury in rat pups. Amniotic fluid supplementation protects rat pups against experimental NEC, which is mediated, at least in part, by HGF.

Hepatocyte growth factor in dampening liver immune-mediated pathology in acute viral hepatitis without compromising antiviral activity.

BACKGROUND AND AIM: Hepatocyte growth factor (HGF) is a pleiotropic cytokine related with cell proliferation and survival; however, its role in viral hepatitis is not elucidated. In this study, we studied HGF immune role in viral hepatitis. METHODS: Mice received hydrodynamically delivered HGF plasmid or control plasmid and then infected with adenovirus, and parameters of immune-mediated liver damage were evaluated. We studied dendritic cell (DC) activation in the presence of HGF. T cells collected from infected mice were restimulated with virally infected DC to measure cytokine production in vitro. RESULTS: HGF ameliorated the liver inflammation during viral hepatitis as alanine transferase, intrahepatic lymphocytes, and splenocyte counts were diminished by HGF. Lower histological scores of liver pathology were observed in the HGF group. DC from the HGF group expressed reduced CD40. The hepatic expression and serum concentration of IL-12p40 were diminished in HGF-transfected mice. In vitro experiments with DC confirmed that HGF diminished CD40 expression and IL-12p40 production. The expression and serum levels of IFN-γ, IL-6 and CXCL9 were significantly decreased in the HGF group. HGF overexpression diminished the expression and concentration of IL-10 and TGF-ß. The frequency of PD-1(+) Tim-3(+) in CD8 T cells was decreased by HGF overexpression. Moreover, T cells in the HGF group at day 14 secreted more IFN-γ and TNF-α than those in the control group when restimulated with virally infected DC. CONCLUSION: HGF modulated DC activation and T cell priming, thereby limiting the immune-mediated damage in the liver. However, viral clearance was not compromised by HGF.

Renoprotective effects of hepatocyte growth factor in the stenotic kidney.

Renal microvascular (MV) damage and loss contribute to the progression of renal injury in renal artery stenosis (RAS). Hepatocyte growth factor (HGF) is a powerful angiogenic and antifibrotic cytokine that we showed to be decreased in the stenotic kidney. We hypothesized that renal HGF therapy will improve renal function mainly by protecting the renal microcirculation. Unilateral RAS was induced in 15 pigs. Six weeks later, single-kidney RBF and GFR were quantified in vivo using multidetector computed tomography (CT). Then, intrarenal rh-HGF or vehicle was randomly administered into the stenotic kidney (RAS, n = 8; RAS+HGF, n = 7). Pigs were observed for 4 additional weeks before CT studies were repeated. Renal MV density was quantified by 3D micro-CT ex vivo and histology, and expression of angiogenic and inflammatory factors, apoptosis, and fibrosis was determined. HGF therapy improved RBF and GFR compared with vehicle-treated pigs. This was accompanied by improved renal expression of angiogenic cytokines (VEGF, p-Akt) and tissue-healing promoters (SDF-1, CXCR4, MMP-9), reduced MV remodeling, apoptosis, and fibrosis, and attenuated renal inflammation. However, HGF therapy did not improve renal MV density, which was similarly reduced in RAS and RAS+HGF compared with controls. Using a clinically relevant animal model of RAS, we showed novel therapeutic effects of a targeted renal intervention. Our results show distinct actions on the existing renal microcirculation and promising renoprotective effects of HGF therapy in RAS. Furthermore, these effects imply plasticity of the stenotic kidney to recuperate its function and underscore the importance of MV integrity in the progression of renal injury in RAS.

In vivo administration of the recombinant IL-7/hepatocyte growth factor ß hybrid cytokine efficiently restores thymopoiesis and naive T cell generation in lethally irradiated mice after syngeneic bone marrow transplantation.

Bone marrow transplantation (BMT) is often followed by a prolonged period of T cell deficiency. Therefore, the enhancement of T cell reconstitution is an important clinical goal. We have identified a novel hybrid cytokine containing IL-7 and the ß-chain of hepatocyte growth factor (HGF) in the supernatant of cultured mouse BM stromal cells. We have cloned and expressed the IL-7/HGFß gene to produce a single-chain rIL-7/HGFß protein that stimulates the in vitro proliferation of thymocytes, early B-lineage cell, and day 12 spleen CFUs. In this study, we show that, following syngenic BMT, the in vivo administration of rIL-7/HGFß supports the rapid and complete regeneration of the thymus and efficiently reconstitutes the pool of naive T cells having a normally diverse TCR repertoire. The rIL-7/HGFß hybrid cytokine was significantly more effective quantitatively than was rIL-7 and differed qualitatively in its ability to cross-link c-Met and IL-7Rα and to stimulate the expansion of early thymocyte progenitors and thymic epithelial cells. It also supports the maturation and homeostatic expansion of peripheral T cells. Consequently, the in vivo administration of rIL-7/HGFß may offer a new approach to preventing and/or correcting post-BMT T cell immune deficiency.

Role of HGF-loaded nanoparticles in treating rat acute hepatic failure.

BACKGROUND/AIMS: To explore the role of hepatocyte growth factor (HGF)-loaded polylactic acid-O-carboxymethylated chitosan (PLA-O-CMC) nanoparticles in hepatocyte transplantation (HCT) for treating rat acute liver failure (ALF). METHODS: Five milliliters of hepatocytes respectively treated with conventional culture (group I), PLA-O-CMC nanoparticles (group II) and HGF-loaded PLA-O-CMC nanoparticles (group III) were transplanted into the abdominal cavities of rat with ALF. In group IV, rats were treated as group II except intravenous 10 pg of HGF daily for 7 days, and in group V, rats were given intraperitoneal RPMI-1640. RESULTS: The survival rate on the 14th day after HCT was higher in groups III IV, and II than in group V (p<0.05). Hepatic function in groups II-IV was improved 24 h after HCT (p<0.05, compared with group V). The recovery of hepatic function was the best in group III. In group III, mitotic index was 10.20% on the 5th day after HCT (p<0.05, compared with other groups) and Ki-67 labeling index was 16.8% on the 7th day after HCT (p<0.05, compared with group V). CONCLUSIONS: HGF-loaded PLA-O-CMC nanoparticles can steadily release HGF, and exhibits better tendencies in liver regeneration, survival rate and hepatic function compared with intravenous HGF.