Anti-Apoptotic Effects of Recombinant Human Hepatocyte Growth Factor on Hepatocytes Were Associated with Intrahepatic Hemorrhage Suppression Indicated by the Preservation of Prothrombin Time

Signaling pathways of liver regeneration: Biological mechanisms and implications

The liver possesses a unique regenerative ability to restore its original mass, in this regard, partial hepatectomy (PHx) and partial liver transplantation (PLTx) can be executed smoothly and safely, which has important implications for the treatment of liver disease. Liver regeneration (LR) can be the very complicated procedure that involves multiple cytokines and transcription factors that interact with each other to activate different signaling pathways. Activation of these pathways can drive the LR process, which can be divided into three stages, namely, the initiation, progression, and termination stages. Therefore, it is important to investigate the pathways involved in LR to elucidate the mechanism of LR. This study reviews the latest research on the key signaling pathways in the different stages of LR.

Transplantation of autologous bone marrow-derived mononuclear cells into cerebrospinal fluid in a canine model of spinal cord injury

Introduction

Spinal cord injury (SCI) is associated with severe dysfunction of nervous tissue, and repair via the transplantation of bone marrow-derived mononuclear cells (BM-MNCs) into cerebrospinal fluid yields promising results. It is essential to understand the underlying mechanisms; therefore, this study aimed to evaluate the regenerative potential of autologous BM-MNC transplantation in a canine model of acute SCI.

Methods

Six dogs were included in this study, and SCI was induced using an epidural balloon catheter between L2 and L3, particularly in the area of the anterior longitudinal ligament. BM-MNC transplantation was performed, and T2-weighted magnetic resonance imaging (MRI) was conducted at specific time points (i.e., immediately after inducing SCI and at 1, 2, and 4 weeks after inducing SCI); moreover, the expression of growth-associated protein 43 (GAP-43) was evaluated.

Results

MRI revealed that the signal intensity reduced over time in both BM-MNC-treated and control groups. However, the BM-MNC-treated group exhibited a significantly faster reduction than the control group during the early stages of SCI induction (BM-MNC-treated group: 4.82 ± 0.135 cm [day 0], 1.71 ± 0.134 cm [1 week], 1.37 ± 0.036 cm [2 weeks], 1.21 cm [4 weeks]; control group: 4.96 ± 0.211 cm [day 0], 2.49 ± 0.570 cm [1 week], 1.56 ± 0.045 cm [2 weeks], 1.32 cm [4 weeks]). During the early stages of treatment, GAP-43 was significantly expressed at the proximal end of the injured spinal cord in the BM-MSC-treated group, whereas it was scarcely expressed in the control group.

Conclusions

In SCI, transplanted BM-MNCs can activate the expression of GAP-43, which is involved in axonal elongation (an important process in spinal cord regeneration). Thus, cell therapy with BM-MNCs can provide favorable outcomes in terms of better regenerative capabilities compared with other therapies.

Isolation, culture, and delivery considerations for the use of mesenchymal stem cells in potential therapies for acute liver failure

Acute liver failure (ALF) is a high-mortality syndrome for which liver transplantation is considered the only effective treatment option. A shortage of donor organs, high costs and surgical complications associated with immune rejection constrain the therapeutic effects of liver transplantation. Recently, mesenchymal stem cell (MSC) therapy was recognized as an alternative strategy for liver transplantation. Bone marrow mesenchymal stem cells (BMSCs) have been used in clinical trials of several liver diseases due to their ease of acquisition, strong proliferation ability, multipotent differentiation, homing to the lesion site, low immunogenicity and anti-inflammatory and antifibrotic effects. In this review, we comprehensively summarized the harvest and culture expansion strategies for BMSCs, the development of animal models of ALF of different aetiologies, the critical mechanisms of BMSC therapy for ALF and the challenge of clinical application.

The Transfer of the Hepatocyte Growth Factor Gene by Macrophages Ameliorates the Progression of Peritoneal Fibrosis in Mice

Growing evidence indicates that hepatocyte growth factor (HGF) possesses potent antifibrotic activity. Furthermore, macrophages migrate to inflamed sites and have been linked to the progression of fibrosis. In this study, we utilized macrophages as vehicles to express and deliver the HGF gene and investigated whether macrophages carrying the HGF expression vector (HGF-M) could suppress peritoneal fibrosis development in mice. We obtained macrophages from the peritoneal cavity of mice stimulated with 3% thioglycollate and used cationized gelatin microspheres (CGMs) to produce HGF expression vector-gelatin complexes. Macrophages phagocytosed these CGMs, and gene transfer into macrophages was confirmed in vitro. Peritoneal fibrosis was induced by intraperitoneal injection of chlorhexidine gluconate (CG) for three weeks; seven days after the first CG injection, HGF-M was administered intravenously. Transplantation of HGF-M significantly suppressed submesothelial thickening and reduced type III collagen expression. Moreover, in the HGF-M-treated group, the number of α-smooth muscle actin- and TGF-β-positive cells were significantly lower in the peritoneum, and ultrafiltration was preserved. Our results indicated that the transplantation of HGF-M prevented the progression of peritoneal fibrosis and indicated that this novel gene therapy using macrophages may have potential for treating peritoneal fibrosis.

The preventive effect of recombinant human hepatocyte growth factor for hepatic steatosis in a rat model of short bowel syndrome

PURPOSE

Short bowel syndrome (SBS) patients require total parenteral nutrition (TPN) following massive small bowel resection (SBR), which may cause intestinal failure-associated liver disease (IFALD), a life-threatening complication. Hepatocyte growth factor (HGF) acts as a potent hepatocyte mitogen with anti inflammatory and antioxidant actions. The present study evaluated the effect of recombinant human HGF (rh-HGF) on SBR and subsequent IFALD using a parentally fed rat model of SBS.

METHODS

Rats underwent jugular vein catheterization for continuous TPN and 90% SBR. They were divided into 2 groups: TPN alone (SBS/TPN group: n = 7) or TPN plus the intravenous administration of rh-HGF (0.3 mg/kg/day) (SBS/TPN+HGF group: n = 7). On day 7, their tissues and stool were harvested to evaluate the effects of HGF.

RESULTS

Regarding the histological findings, based on the nonalcoholic fatty liver disease (NAFLD) activity score, the SBS/TPN+HGF group showed significantly less hepatic steatosis and inflammatory cell infiltration than the SBS/TPN group (NAFLD activity score, 4.00 ± 1.83 vs. 1.00 ± 0.82; p < 0.01). The SBS/TPN+HGF group showed a higher expression of Farnesoid X receptor in the liver and lower expression of Toll-like receptor 4 in the ileum than the SBS/TPN group. Regarding the composition of the bacterial gut microbiota, Actinobacteria, Bacteroidetes and Proteobacteria were decreased in the SBS/TPN+HGF group compared with the SBS/TPN group.

CONCLUSION

In our SBS with TPN rat model, rh-HGF administration had a preventive effect against hepatic steatosis and dysbiosis. rh-HGF may therefore be a potentially effective therapeutic agent for SBS and subsequent IFALD.

TYPE OF STUDY

Experimental research.

HGF/c-Met: A Key Promoter in Liver Regeneration

Hepatocyte growth factor (HGF) is a peptide-containing multifunctional cytokine that acts on various epithelial cells to regulate cell growth, movement and morphogenesis, and tissue regeneration of injured organs. HGF is sequestered by heparin-like protein in its inactive form and is widespread in the extracellular matrix of most tissues. When the liver loses its average mass, volume, or physiological and biochemical functions due to various reasons, HGF binds to its specific receptor c-Met (cellular mesenchymal-epithelial transition) and transmits the signals into the cells, and triggers the intrinsic kinase activity of c-Met. The downstream cascades of HGF/c-Met include JAK/STAT3, PI3K/Akt/NF-κB, and Ras/Raf pathways, affecting cell proliferation, growth, and survival. HGF has important clinical significance for liver fibrosis, hepatocyte regeneration after inflammation, and liver regeneration after transplantation. And the development of HGF as a biological drug for regenerative therapy of diseases, that is, using recombinant human HGF protein to treat disorders in clinical trials, is underway. This review summarizes the recent findings of the HGF/c-Met signaling functions in liver regeneration.

The protective effects of hepatocyte growth factor on the intestinal mucosal atrophy induced by total parenteral nutrition in a rat model

PURPOSE

Total parental nutrition (TPN) causes gastrointestinal mucosal atrophy. The present study investigated the effects of hepatocyte growth factor (HGF) on the intestinal mucosal atrophy induced by TPN.

METHODS

Rats underwent jugular vein catheterization and were divided into four groups: oral feeding (OF), TPN alone (TPN), TPN plus low-dose HGF (0.3 mg/kg/day; TPNLH), and TPN plus high-dose HGF (1.0 mg/kg/day; TPNHH). On day 7, rats were euthanized, and the small intestine was harvested and evaluated histologically. The expression of c-MET, a receptor of HGF, and nutrition transporter protein were evaluated using quantitative polymerase chain reaction.

RESULTS

The jejunal villus height (VH) and absorptive mucosal surface area in the TPNHH group were significantly higher than in the TPN group (p < 0.05). The VH in the ileum showed the same trend only in the TPNHH group, albeit without statistical significance. The crypt cell proliferation rate (CCPR) of the jejunum in both HGF-treated groups was significantly higher than in the TPN group (p < 0.01). The expression of c-MET and transporter protein in all TPN-treated groups was decreased compared with that in the OF group.

CONCLUSION

HGF attenuated TPN-associated intestinal mucosal atrophy by increasing the villus height, which was associated with an increase in CCPR.

Comparative analysis of canine mesenchymal stem cells and bone marrow-derived mononuclear cells

Background and aim:

Mesenchymal stem cells (MSCs), which have multi-lineage differentiation potentials, are a promising source for regenerative medicine. However, the focus of study of MSCs is shifting from the characterization of the differentiation potential to their secretion potential for cell transplantation. Tissue regeneration and the attenuation of immune responses are thought to be affected by the secretion of multiple growth factors and cytokines by MSCs. However, the secretion potential of MSCs profiling remains incompletely characterized. In this study, we focused on the secretion ability related and protein mRNA expression of dog adipose tissue-derived MSCs (AT-MSC), bone marrow (BM)-derived MSCs, and BM-derived mononuclear cells (BM-MNC).

Materials and Methods:

Real-time polymerase chain reaction analyses revealed mRNA expression of nine growth factors and seven interleukins in these types of cells and three growth factors protein expression were determined using Enzyme-linked immunosorbent assay.

Results:

For the BM-MNC growth factors, the mRNA expression of transforming growth factor-β (TGF-β) was the highest. For the BM-derived MSC (BM-MSC) and AT-MSC growth factors, the mRNA expression of vascular endothelial growth factor (VEGF) was highest. BM-MSCs and AT-MSCs showed similar expression profiles. In contrast, BM-MNCs showed unique expression profiles for hepatocyte growth factor and epidermal growth factor. The three types of cells showed a similar expression of TGF-β.

Conclusion:

We conclude that expression of cytokine proteins and mRNAs suggests involvement in tissue repair and protection.

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.

The administration of hepatocyte growth factor prevents total parenteral nutrition-induced hepatocellular injury in a rat model

PURPOSE

Total parenteral nutrition (TPN) sometimes induces parenteral nutrition-associated liver disease (PNALD). Hepatocyte growth factor (HGF) acts as a potent hepatocyte mitogen anti-inflammatory and antioxidant actions. We aimed to evaluate the effect of HGF on PNALD in a rat model of TPN.

METHODS

A catheter was placed in the right jugular vein for 7-day continuous TPN. All rats were divided into three groups: TPN alone (TPN group), TPN plus intravenous HGF at 0.3 mg/kg/day [TPN + HGF (low) group], and TPN plus HGF at 1.0 mg/kg/day [TPN + HGF (high) group]. On day 7, livers were harvested and the histology, inflammatory cytokines and apoptosis were evaluated.

RESULTS

Histologically, lipid droplets were apparent in the TPN group, but decreased in the TPN + HGF (low) and TPN + HGF (high) groups. The histological nonalcoholic fatty liver disease activity scores in the TPN + HGF (low) and TPN + HGF (high) groups were significantly lower than that in the TPN group (p < 0.01). There were no significant differences in the inflammatory cytokine levels of the three groups. The caspase-9 expression levels in the TPN + HGF (low) and TPN + HGF (high) groups were significantly decreased in comparison to that in the control group (p < 0.05).

CONCLUSION

The intravenous administration of HGF attenuated hepatic steatosis induced by 7-day TPN dose dependently.

Roseotoxin B alleviates cholestatic liver fibrosis through inhibiting PDGF-B/PDGFR-β pathway in hepatic stellate cells

Identifying effective anti-fibrotic therapies is a major clinical need that remains unmet. In the present study, roseotoxin B was shown to possess an improving effect on cholestatic liver fibrosis in bile duct–ligated mice, as proved by histochemical and immunohistochemical staining, hepatic biochemical parameters, and TUNEL apoptotic cell detection in tissue sections. Using cellular thermal shift assay, computational molecular docking, microscale thermophoresis technology, and surface plasmon resonance biosensor, we confirmed that PDGFR-β was a direct target of roseotoxin B in fibrotic livers. Of note, human tissue microarrays detected pathologically high expression of p-PDGFR-β in liver samples of ~80% of patients with liver fibrosis and cirrhosis. PDGF-B/PDGFR-β pathway promotes transdifferentiation and excessive proliferation of hepatic stellate cells (HSCs), which is a very crucial driver for liver fibrosis. Meaningfully, roseotoxin B blocked the formation of PDGF-BB/PDGFR-ββ complex by targeting the D2 domain of PDGFR-β, thereby inhibiting the PDGF-B/PDGFR-β pathway in HSCs. In summary, our study provided roseotoxin B as a unique candidate agent for the treatment of liver fibrosis.