Modulation of the inflammatory response and apoptosis using epidermal growth factor and hepatocyte growth factor in a liver injury model: a potential approach to the management and treatment of cholestatic liver disease

Potential mechanisms underlying the effect of hepatocyte growth factor on liver injury in short bowel syndrome model rats

PURPOSE

The purpose of this study was to investigate the autophagy associated with apoptosis in hepatic damage in the short bowel syndrome rat model.

METHODS

SD rats underwent jugular vein catheterization for continuous total parenteral nutrition (TPN) and 90% small bowel resection. Animals were divided into two groups: TPN plus SBS (Control group) or TPN plus SBS plus intravenous administration of HGF (HGF group). On day 7, the rats were harvested, and hepatocellular injury was evaluated.

RESULTS

In an SBS rat model, hepatic steatosis and lobular inflammation were histologically suppressed in the HGF group (p < 0.01). The expression of tumor necrosis factor-α in the HGF group tend to be higher than that in the control group (p = 0.13). The gene expression of transforming Growth Factor-β in the HGF group was suppressed compared to the control group (p < 0.01). HGF treatment may have an antiapoptotic effect via the intrinsic pathway by caspase 9. Protein expressions of Rubicon (p = 0.03) and p62 (p < 0.01) in the HGF group were found to have increased compared to those in the control group.

CONCLUSION

The inhibitory effect of HGF on hepatic steatosis remains unclear, and further studies focusing on the mechanisms of fat accumulation are needed.

Ginseng polysaccharide reduces autoimmune hepatitis inflammatory response by inhibiting PI3K/AKT and TLRs/NF-κB signaling pathways

BACKGROUND

Ginseng polysaccharides (GP) have been found to exhibit significant immune regulatory effects, making them a promising candidate for treating immune-related diseases. However, their mechanism of action in immune liver injury is not yet clear. The innovation of this study lies in exploring the mechanism of action of ginseng polysaccharides (GP) in immune liver injury. While GP has been previously identified for its immune regulatory effects, this study aims to provide a clearer understanding of its therapeutic potential for immune-related liver diseases.

PURPOSE

The purpose of this study is to characterize low molecular weight gingeng polysaccharides (LGP), investigate their effect on ConA-induced autoimmune hepatitis (AIH), and identify their potential molecular mechanisms.

METHODS

LGP was extracted and purified using water-alcohol precipitation, DEAE-52 cellulose column, and Sephadex G200. And its structure was analyzed. It was then evaluated for anti-inflammatory and hepatoprotective effects in ConA-induced cells and mice, assessing cellular viability and inflammation with Cell Counting Kit-8 (CCK-8), Reverse Transcription-polymerase Chain Reaction (RT-PCR), and Western Blot, and hepatic injury, inflammation, and apoptosis with various biochemical and staining methods.

RESULTS

LGP is a polysaccharide composed of glucose (Glu), galactose (Gal), and arabinose (Ara), with a molar ratio of 12.9:1.6:1.0. LGP has a low crystallinity amorphous powder structure and is free from impurities. LGP enhances cell viability and reduces inflammatory factors in ConA-induced RAW264.7 cells and inhibits inflammation and hepatocyte apoptosis in ConA-induced mice. LGP inhibits Phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) and Toll-like receptors/Nuclear factor kappa B (TLRs/NF-κB) signaling pathways in vitro and in vivo to treat AIH.

CONCLUSIONS

LGP was successfully extracted and purified, exhibiting potential as a treatment for ConA-induced autoimmune hepatitis due to its ability to inhibit the PI3K/AKT and TLRs/NF-κB signaling pathways and protect liver cells from damage.

The effect of hepatocyte growth factor on intestinal adaption in an experimental model of short bowel syndrome

PURPOSE

Nowadays, the standard therapy for patients with short bowel syndrome is parenteral nutrition (PN). Various growth factors have been tested to achieve weaning from prolonged PN administration. We evaluated the effect of hepatocyte growth factor (HGF) on structural intestinal adaptation and cell proliferation in a rat model of SBS.

METHODS

Thirty Sprague-Dawley rats were divided into three groups; group A rats (sham) underwent bowel transection, group B rats underwent a 75% bowel resection, and group C rats underwent the same procedure but were treated postoperatively with HGF. Histopathologic parameters of intestinal adaptation were determined, while microarray and rt-PCR analyses of ileal RNA were also performed.

RESULTS

Treatment with HGF resulted in significant increase in body weight, while the jejunal and ileal villus height and crypt depth were increased in HGF rats (36%, p < 0.05 and 27%, p < 0.05 respectively). Enterocyte proliferation was also significantly increased in HGF rats (21% p < 0.05). Microarray and quantitative rt-PCR analyses showed that the genes hgfac, rac 1, cdc42, and akt 1 were more than twofold up-regulated after HGF treatment.

CONCLUSION

HGF emerges as a growth factor that enhances intestinal adaptation. The future use of HGF may potentially reduce the requirement for PN in SBS patients.

Sweroside ameliorates α-naphthylisothiocyanate-induced cholestatic liver injury in mice by regulating bile acids and suppressing pro-inflammatory responses

AIM

Sweroside is an iridoid glycoside with diverse biological activities. In the present study we investigated the effects of sweroside on α-naphthylisothiocyanate (ANIT)-induced cholestatic liver injury in mice.

METHODS

Mice received sweroside (120 mg·kg(-1)·d(-1), ig) or a positive control INT-747 (12 mg·kg(-1)·d(-1), ig) for 5 d, and ANIT (75 mg/kg, ig) was administered on d 3. The mice were euthanized on d 5, and serum biochemical markers, hepatic bile acids and histological changes were analyzed. Hepatic expression of genes related to pro-inflammatory mediators and bile acid metabolism was also assessed. Primary mouse hepatocytes were exposed to a reconstituted mixture of hepatic bile acids, which were markedly elevated in the ANIT-treated mice, and the cell viability and expression of genes related to pro-inflammatory mediators were examined.

RESULTS

Administration of sweroside or INT-747 effectively ameliorated ANIT-induced cholestatic liver injury in mice, as evidenced by significantly reduced serum biochemical markers and attenuated pathological changes in liver tissues. Furthermore, administration of sweroside or INT-747 significantly decreased ANIT-induced elevation of individual hepatic bile acids, such as β-MCA, CA, and TCA, which were related to its effects on the expression of genes responsible for bile acid synthesis and transport as well as pro-inflammatory responses. Treatment of mouse hepatocytes with the reconstituted bile acid mixture induced significant pro-inflammatory responses without affecting the cell viability.

CONCLUSION

Sweroside attenuates ANIT-induced cholestatic liver injury in mice by restoring bile acid synthesis and transport to their normal levels, as well as suppressing pro-inflammatory responses.

The role of growth factors on hepatic damage in rats with obstructive jaundice

In this study, we investigated the affect and the role of growth factors on liver damage. 110 Sprague–Dawley rats were divided into 11 groups: a sham group, a control group, HGF, EGF, IGF, TGF groups of irreversible jaundiced rats and a control group and HGF, EGF, IGF, and TGF groups of reversible jaundiced rats (n = 10). In the irreversible jaundiced groups, the common bile duct was explorated, double ligated, and cut. 150 μg/kg/day HGF, 5 μg/kg/day EGF, 5 μg/kg/day IGF, and 5 μg/kg/day TGF β-1 were injected intraperitoneally after the seventh post-operative day. In the reversible jaundiced group, the common bile duct was ligated and the ligation was resolved on the seventh post-operative day. For 5 days, growth factors were injected at the same dose. Ductal proliferation scores significantly decreased after growth factor administration in the EGF-A and TGF-A groups. Furthermore, ductal proliferation was decreased in the TGF-B group. As a result of this study, HGF was effective in the irreversible jaundiced groups and ineffective in the reversible jaundice groups. EGF was effective in the reversible jaundiced groups and ineffective in the irreversible jaundiced groups. In both the irreversible jaundiced and reversible jaundiced groups, IGF was ineffective, although TGF β-1 was effective. We believe that these results arise from the positive effects of effective doses of growth factor on liver damage.

Recombinant adenovirus containing hyper-interleukin-6 and hepatocyte growth factor ameliorates acute-on-chronic liver failure in rats

AIM: To investigate the protective efficacy of recombinant adenovirus containing hyper-interleukin-6 (Hyper-IL-6, HIL-6) and hepatocyte growth factor (HGF) (Ad-HGF-HIL-6) compared to that of recombinant adenovirus containing either HIL-6 or HGF (Ad-HIL-6 or Ad-HGF) in rats with acute-on-chronic liver failure (ACLF).

METHODS: The recombinant adenoviruses containing HIL-6 and/or HGF were constructed. We established an ACLF model, and rats were randomly assigned to control, model, Ad-GFP, Ad-HIL-6, Ad-HGF or Ad-HGF-HIL-6 group. We collected serum and liver tissue samples to test pathological changes, biochemical indexes and molecular biological indexes.

RESULTS: Attenuated alanine aminotransferase, prothrombin time, high-mobility group box 1 (HMGB1), endotoxin, tumour necrosis factor (TNF)-α and interferon-γ were observed in the Ad-HGF-, Ad-HIL-6- and Ad-HGF-HIL-6-treated rats with ACLF. Likewise, reduced hepatic damage and apoptotic activity, as well as reduced HMGB1 and Bax proteins, but raised expression of Ki67 and Bcl-2 proteins and Bcl-2/Bax ratio were also observed in the Ad-HGF-, Ad-HIL-6- and Ad-HGF-HIL-6-treated rats with ACLF. More significant changes were observed in the Ad-HGF-HIL-6 treatment group without obvious side effects. Furthermore, caspase-3 at the protein level decreased in the Ad-HIL-6 and Ad-HGF-HIL-6 treatment groups, more predominantly in the latter group.

CONCLUSION: This study identifies that the protective efficacy of Ad-HGF-HIL-6 is more potent than that of Ad-HGF or Ad-HIL-6 in ACLF rats, with no significant side effects.

Hepatocyte growth factor, hepatocyte growth factor activator and arginine in a rat fulminant colitis model

Introduction

Dextran sodium sulfate (DSS) is commonly used to induce a murine fulminant colitis model. Hepatocyte growth factor (HGF) has been shown to decrease the symptoms of inflammatory bowel disease (IBD) but the effect of its activator, HGFA, is not well characterized. Arginine reduces effects of oxidative stress but its effect on IBD is not well known. The primary aim is to determine whether HGF and HGFA, or arginine will decrease IBD symptoms such as pain and diarrhea in a DSS-induced fulminant colitis murine model.

Methods

A severe colitis was induced in young, male Fischer 344 rats with 4% (w/v) DSS oral solution for seven days; rats were sacrificed on day 10. Rats were divided into five groups of 8 animals: control, HGF (700 mcg/kg/dose), HGF and HGFA (10 mcg/dose), HGF and arginine, and high dose HGF (2800 mcg/kg/dose). Main clinical outcomes were pain, diarrhea and weight loss. Blinded pathologists scored the terminal ileum and distal colon.

Results

DSS reliably induced severe active colitis in 90% of animals (n = 36/40). There were no differences in injury scores between control and treatment animals. HGF led to 1.38 fewer days in pain (p = 0.036), while arginine led to 1.88 fewer days of diarrhea (P = 0.017) compared to controls. 88% of HGFA-treated rats started regaining weight (P < 0.001).

Discussion/Conclusion

Although treatment was unable to reverse fulminant disease, HGF and arginine were associated with decreased days of pain and diarrhea. These clinical interventions may reduce associated symptoms for severe IBD patients, even when urgent surgical intervention remains the only viable option.

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We developed a fulminant colitis model in adolescent rats.

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The fulminant colitis model reproduces inflammatory bowel disease in humans.

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The rats were treated with hepatocyte growth factor, its activator, and arginine.

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The HGF treated rats had fewer days of pain.

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The arginine treated rats had fewer days of diarrhea.

Autoserum: An Optimal Supplement for Bone Marrow Mesenchymal Stem Cells of Liver-Injured Rats

Mesenchymal stem cells (MSCs) are an attractive source for the clinical cell therapy of liver injury. Although the use of adult serum, platelet lysate, or cord blood serum solves some of the problems caused by fetal bovine serum (FBS), the allogeneic immune response, contamination, and donor-to-donor and donor-to-receptor differences still obstruct the application of MSCs. In this study, the influences of autoserum from liver-injured rats (LIRs) and allogeneic serum from healthy rats on the isolation and culture of bone marrow MSCs (BMSCs) were examined and compared to FBS. The results showed that BMSCs cultured with autoserum or allogeneic serum exhibited better MSC-specific morphology, lower rate of cell senescent, and higher proliferation kinetics than those with FBS. In addition, autoserum promoted the osteogenic differentiation potential of BMSCs as allogeneic serum did. Although there were no significant differences in proliferation activity, immunophenotypic characterization, and differentiation potential between BMSCs cultured with autoserum and those with allogeneic serum, the potential adverse immunological reactions in patients with allogeneic material transplantation must be considered. We therefore believe that the autoserum from liver-injured patients may be a better choice for MSC expansion to meet the needs of liver injury therapy.

Effect of alpha-naphthylisothiocyanate-induced liver injury on intestinal adaptation in a rat model of short bowel syndrome

BACKGROUND/PURPOSE

Progressive hyperbilirubinemia and end-stage liver failure are among the most serious complications of short bowel syndrome (SBS), representing the principle cause of death in a majority of fatal cases. In the current study, we examined the effects of alpha-naphthylisothiocyanate (ANIT)-induced liver injury on intestinal adaptation in a rat model of SBS.

METHODS

Male rats were divided into four groups: Sham rats underwent bowel transection (n = 8), Sham liver-injury rats underwent bowel transection and IP injection of ANIT (100 mg/kg, n = 8), SBS rats underwent a 75% bowel resection, and SBS-ANIT rats underwent bowel resection and liver injury similar to group sham-ANIT (n = 8). Fourteen days after intervention, liver biopsies and intestinal samples were obtained and evaluated for liver damage and measures of intestinal adaptation. Real time PCR and Western blotting were used to determine the level of bax and bcl-2 mRNA and protein, and p-ERK protein levels. Statistical analysis was performed using the one-way ANOVA test, with p < 0.05 considered statistically significant.

RESULTS

All ANIT-treated animals exhibited histological evidence of liver damage that was associated with the expansion of atypical ductal proliferation near the periportal areas, intense neutrophil infiltration in the liver, increased mitotic activity, Kupfer cells hyperplasia and fatty liver degeneration. ANIT-induced liver damage in bowel resected animals was associated with a significant decrease in all parameters of intestinal adaptation including bowel and mucosal weight in jejunum (twofold decrease) and ileum (twofold decrease), mucosal DNA in jejunum (fourfold decrease), mucosal protein in jejunum (threefold decrease) and ileum (threefold decrease), villus height in jejunum (38%) and ileum (34%), and crypt depth in jejunum (24%) and ileum (30%) compared to SBS animals. Both Sham-ANIT and SBS-ANIT rats demonstrated decreased enterocyte proliferation rates that were accompanied by decreased p-ERK protein levels. Lower apoptotic rates in jejunum (40%) and ileum (52%) in SBS-ANIT rats (vs. SBS) coincided with decreased bax mRNA and protein levels.

CONCLUSIONS

In a rat model of SBS, ANIT-induced liver injury was associated with decreased enterocyte proliferation and inhibited intestinal adaptation.

The effect of hepatocyte growth factor on gene transcription during intestinal adaptation

PURPOSE

Previously, we investigated the physiologic effects of hepatocyte growth factor (HGF) on intestinal adaptation using a massive small bowel resection (MSBR) rat model. To correlate these altered physiologic changes with gene alterations, we used microarray technology at 7, 14, and 21 days after MSBR.

METHODS

Forty-five adult female rats were divided into 3 groups and underwent 70% MSBR, MSBR + HGF (intravenous 150 μg/kg per day), or sham operation (control). Five animals per group were killed at each time point. Ileal mucosa was harvested and RNA extracted. Rat Gene Chips and Expression Console software (Affymetrix, Santa Clara, CA) were used. Statistical analysis was done by analysis of variance using Partek Genomics Suite (Partek, Inc, St Louis, MO). Results were significant if fold change was more than 2 or less than -2, with P < .05.

RESULTS

Compared with the control group, MSBR group had significant increases in up-regulated and down-regulated genes. The MSBR-HGF group had further increases in up-regulated and down-regulated genes compared with the MSBR group. At 7 days, 6 cellular hypertrophy families had 30 genes up-regulated, and HGF up-regulated an additional 14 genes. At 21 days, 5 hyperplasia gene families had 32 up-regulated genes. Hepatocyte growth factor up-regulated an additional 16 genes.

CONCLUSIONS

Microarray analysis of intestinal adaptation identified an early emphasis on hypertrophy and later emphasis on hyperplasia. This is the first demonstration that the effect of HGF on intestinal adaptation is recruitment of more genes rather than an increase in the fold change of already up-regulated genes.

Dose variation of hepatocyte growth factor and its effects on an animal model of TPN-induced liver injury

BACKGROUND

Total parenteral nutrition (TPN) induced liver failure is the leading indication for transplantation in children. Our previous research demonstrated the benefit of a specific intravenous dose of hepatocyte growth factor (HGF) in the amelioration of TPN-induced liver injury. This study was designed to ascertain the optimum concentration of HGF in an animal model of TPN-induced liver injury.

MATERIALS AND METHODS

Twenty adult female Sprague-Dawley rats underwent 70% small bowel resection and placement of venous catheters connected to subcutaneous osmotic minipumps. Four groups (n=5 each) based on the contents of the osmotic pump were utilized as follows: group 1 (control): saline; group 2: HGF 75 mcg/kg/d; group 3: HGF 150 mcg/kg/d; and group 4: HGF 250 mcg/kg/d. Each rat received 14 d of TPN without enteral nutrition. After sacrifice, the liver was harvested. Hepatic inflammation was evaluated using antibodies for TNF-α and IL-6. Apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) technique.

RESULTS

All concentrations induced statistically significantly less IL-6 and TNF- α expression compared to the control animals. Increased efficacy was demonstrated with increasing dose concentration up to 150 mcg/kg/d but not 250 mcg/kg/d. Apoptotic activity was decreased statistically significantly for all dose concentrations compared with the controls, as well as to increases in dose concentration.

CONCLUSIONS

Increasing concentrations of HGF were directly correlated with increased modulation of inflammatory response and apoptotic index in this animal model for TPN-induced liver injury, up to 150 mcg/kg/d. Further increases were significant with respect to apoptotic index only. Further investigations are warranted to determine if HGF may be useful to minimize TPN-induced liver injury in children.

Growth factor modulation of hepatic inflammation: a novel approach to the management of total parenteral nutrition-associated liver disease

PURPOSE

Dependence on total parenteral nutrition in intestinal failure or short bowel syndrome patients can lead to many complications. The most significant complication is progressive liver injury leading to liver failure. This study assesses the potential of hepatocyte growth factor (HGF) in modulating the hepatic response in a rat cholestatic liver injury model.

METHODS

Female Sprague-Dawley rats were divided into 3 groups: control (n = 5), chronic liver injury (alpha-naphtylisocyocyanate [ANIT] every 3.5 days at 75 mg/kg; n = 5), and chronic liver injury plus HGF (ANIT + HGF at 250 microg kg(-1) d(-1); n = 5). The rats initially underwent massive (80%) small bowel resections. Seven days later, they were given intraperitoneal injections of saline (control) or ANIT and implantation of an osmotic minipump for continuous intravenous saline or HGF. Intraperitoneal saline or ANIT injections were subsequently administered every 3.5 days to create a chronic cholestatic model. After 14 days, the animals were euthanized, and liver biopsies were obtained. The liver biopsies were evaluated by histology, immunofluorescence staining for interleukin-6 and tumor necrosis factor alpha, and assessment of apoptosis by terminal dUTP-transferase-mediated nick end labeling (TUNEL) technique.

RESULTS

In this chronic liver injury model, HGF did not effect the grade of inflammation. However, HGF did induce retention of the ductal structures and avoided ductal proliferation, damage, and evidence of primary sclerosing cholangitis (P < .05). Hepatocyte growth factor induced less interleukin-6 (P < .011) and tumor necrosis factor alpha (P < .01) expression. Apoptotic activity was also significantly less in the HGF group (P < .01).

CONCLUSION

Hepatocyte growth factor preserved the hepatic ductal system, modulated the hepatic inflammatory response, and reduced the apoptotic index in this chronic cholestatic liver injury model. It may diminish or prevent liver damage in patients with total parenteral nutrition-induced liver injury.