IGF-1 alleviates CCL4-induced hepatic cirrhosis and dysfunction of intestinal barrier through inhibition TLR4/NF-κB signaling mediated by down-regulation HMGB1.

INTRODUCTION AND OBJECTIVES: Cirrhosis has gradually become a serious public health issue, especially the national prevalence of cirrhosis was 29.2% in northwest China. Recent evidence has revealed that intestinal barrier (IB) dysfunction results from and contributes to cirrhosis. Our previous results have indicated that insulin-like growth factors (IGF-1) improved the impaired IB function and downregulated high mobility group protein box-1 (HMGB-1). Nevertheless, the role of the IGF-1/HMGB1 axis in cirrhosis remains largely unknown. MATERIALS AND METHODS: Western blotting and qRT-PCR were used to detect protein and mRNA levels of related genes. The levels of AST, ALT, IL-1ß, and TNF-α were examined using commercial kits. Immunofluorescence was used to evaluate the expression of HMGB1 in tissues. RESULTS: In carbon tetrachloride (CCl4)-treated rat, the levels of AST (380.12 vs. 183.97), ALT (148.12 vs. 53.56), IL-1ß (155.94 vs. 55.60), and TNF-α (155.00 vs. 48.90) were significantly increased compared with the control group, while IGF-1 treatment significantly alleviated CCL4-induced inflammatory response and IB dysfunction by downregulating HMGB1-mediated the TLR4/MyD88/NF-κB signaling pathway. In vitro experiments, HMGB1 treatment promoted inflammatory cytokines secretion and reduced cell viability and tight junctions by activating the TLR4/MyD88/NF-κB signaling pathway in Caco-2 cells, but IGF-1 alleviated these effects. CONCLUSION: Our findings suggest that IGF-1 might serve as a potential therapeutic target for cirrhosis and IB dysfunction via inactivation of the TLR4/MyD88/NF-κB pathway through down-regulation HMGB1.

Impact of lifestyle interventions targeting physical exercise and caloric intake on cirrhosis regression in rats.

In patients, advanced cirrhosis only regresses partially once the etiological agent is withdrawn. Animal models for advanced cirrhosis regression are missing. Lifestyle interventions (LIs) have been shown to improve steatosis, inflammation, fibrosis, and portal pressure (PP) in liver disease. We aimed at characterizing cirrhosis regression after etiological agent removal in experimental models of advanced cirrhosis and to study the impact of different LI on it. Advanced cirrhosis was induced in rats either by carbon tetrachloride (CCl4) or by thioacetamide (TAA) administration. Systemic and hepatic hemodynamics, liver fibrosis, hepatic stellate cell (HSC) activation, hepatic macrophage infiltration, and metabolic profile were evaluated after 48 h, 4 wk or 8 wk of etiological agent removal. The impact of LI consisting in caloric restriction (CR) or moderate endurance exercise (MEE) during the 8-wk regression process was analyzed. The effect of MEE was also evaluated in early cirrhotic and in healthy rats. A significant reduction in portal pressure (PP), liver fibrosis, and HSC activation was observed during regression. However, these parameters remained above those in healthy animals. During regression, animals markedly worsened their metabolic profile. CR although preventing those metabolic disturbances did not further reduce PP, hepatic fibrosis, or HSC activation. MEE also prevented metabolic disturbances, without enhancing, but even attenuating the reduction of PP, hepatic fibrosis, and HSC activation achieved by regression. MEE also worsened hepatic fibrosis in early-TAA cirrhosis and in healthy rats.NEW & NOTEWORTHY We have developed two advanced cirrhosis regression experimental models with persistent relevant fibrosis and portal hypertension and an associated deteriorated metabolism that mimic what happens in patients. LI, despite improving metabolism, did not enhance the regression process in our cirrhotic models. CR did not further reduce PP, hepatic fibrosis, or HSC activation. MEE exhibited a profibrogenic effect in the liver blunting cirrhosis regression. One of the potential explanations of this worsening could be ammonia accumulation.

RSPO4-CRISPR alleviates liver injury and restores gut microbiota in a rat model of liver fibrosis.

Wnt signaling dysfunction and gut dysbiosis may lead to liver fibrosis, yet the underlying mechanisms are not well elucidated. This study demonstrated the role of RSPO4, a Wnt signaling agonist, in liver fibrogenesis and its impact on the gut microbiome. RSPO4 gene in CCl4-induced fibrotic-liver rats was knockout by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) system, with healthy rats served as the control. Tissue samples and hepatic stellate cells (HSCs) isolated from rats were examined for curative effect of RSPO4-CRISPR treatment. Fecal sample were collected and analyzed with 16 S rRNA sequencing. We found RSPO4-CRISPR relieved liver fibrosis in rats and reversed HSC activation. Further, results showed RSPO4-CRISPR tended to restore the microflora composition. Significance species between groups were identified. Bacteroides and Escherichia-Shigella were the key microbes in the model and negative group, whereas Lactobacillus, Romboutsia, and Lachnospiraceae NK4A136 group were abundant in the control. Notably, Bacteroidales S24-7 group and Ruminococcaceae UCG-005 were the significantly enriched in CRISPR group. We show that the microbiome of rats treated with RSPO4-CRISPR presents a trend towards the restoration of the original condition. Our findings pave a new way to evaluate the curative effect of liver fibrosis treatment.

Células madre adiposas humanas disminuyen el daño de la fibrosis hepática con baja persistencia de células trasplantadas en ratas / Human adipose stem cells decrease liver fibrosis damage with low persistence of transplanted cells in rats

RESUMEN: En la enfermedad hepática crónica el trasplante ortotópico es la única alternativa terapéutica actual pero es limitada por falta de donantes. Ensayos con células madre adultas en daño hepático agudo evidencian promisorios resultados. El objetivo de este trabajo fue evaluar en ratas con daño hepático crónico la efectividad de la infusión de células madre adiposas humanas (CMAd-h). Ratas con fibrosis hepática inducida por tioacetamida fueron agrupadas en: grupo I control que no recibió tioacetamida ni células madre, grupo II recibió tioacetamida y suero fisiológico i.v., grupo III recibió tioacetamida y células madre adiposas 1 x 106/kg i.v. vía vena de la cola. La regeneración hepática histológica se evaluó por el index METAVIR, mientras las Macrophagocytus stellatus, células estrelladas a- SMA+ y células colágeno I+ por inmunohistoquímica; el daño funcional se evaluó por los niveles sanguíneos de los analitos Aspartato Aminotransferasa (AST), Alanina Aminotransferasa (ALT), Fosfatasa Alcalina (ALP), úrea y nitrógeno ureico (BUN) y hemograma. Los resultados muestran atenuación del daño estructural hepático evidenciado por disminución de los nódulos, del grado de lesión histológica en el score Metavir, y disminución de Macrophagocytus stellatus, células a-SMA+ y células colágeno tipo I+; funcionalmente hay reducción moderada de AST, ALT, urea, BUN y disminución moderada de células blancas pero efecto favorable sobre el volumen corpuscular media y la hemoglobina corpuscular media. Ocho semanas después de la infusión hay escasa población de CMAd-h en el hígado. En conclusión la infusión intravenosa de CMAd-h en ratas disminuye el daño funcional y estructural de la fibrosis hepática con escasa persistencia de CMAd-h en el parénquima hepático. A nuestro conocimiento este es el primer trabajo que evalúa el efecto de las CMAd-h en el modelo daño hepático crónico murino y la persistencia de las células trasplantadas.

SUMMARY: In chronic liver disease, orthotopic transplantation is the only current therapeutic alternative but it is limited due to lack of donors. Trials with adult stem cells in acute liver damage show promising results. The aim of this work was to evaluate the effectiveness of human adipose stem cell (h-ASC) infusion in rats with chronic liver damage. Rats with thioacetamide- induced liver fibrosis were grouped into: group I control that did not receive thioacetamide and h-ASC, group II received thioacetamide and saline i.v., group III received thioacetamide and h-ASC 1 x 106/ kg i.v. via tail vein. Histological liver regeneration was evaluated by METAVIR index, while Macrophagocytus stellatus (Kupffer cells), stellate cells a-SMA+ and collagen I+ cells by immunohistochemistry; functional damage was evaluated by blood levels of the analytes Aspartate Aminotransferase (AST), Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Urea and Blood Urea Nitrogen (BUN) and hemogram. The results show attenuation of structural liver damage evidenced by decreased nodules, degree of histologic injury on Metavir score, and decreased Macrophagocytus stellatus, a-SMA+ cells and type I+ collagen cells; functionally there is moderate reduction of AST, ALT, urea, BUN and moderate decrease of white cells but favorable effect on mean corpuscular volume and mean corpuscular hemoglobin. Eight weeks after infusion there is a small population of h-ASC in the liver. In conclusion, intravenous infusion of h-ASC in rats reduces functional and structural damage of hepatic fibrosis with low persistence of h- ASC in the liver parenchyma. To our knowledge this is the first work that evaluates the effect of h-SC in the model of chronic murine liver damage and the persistence of transplanted cells.

Short hairpin RNA attenuates liver fibrosis by regulating the PPAR­Î³ and NF­κB pathways in HBV­induced liver fibrosis in mice.

Progressive liver fibrosis, caused by chronic viral infection and metabolic disorders, results in the development of cirrhosis and hepatocellular carcinoma. However, no antifibrotic therapies have been approved to date. In our previous study, adeno­associated virus (AAV) short hairpin RNAs (shRNAs) targeting hepatitis B virus (HBV) and transforming growth factor (TGF)­ß administration could persistently inhibit HBV replication and concomitantly prevent liver fibrosis. However, the differentially expressed proteins and critical regulatory networks of AAV­shRNA treatment remain unclear. Accordingly, in the present study, we aimed to analyze differentially expressed proteins in the liver of AAV­shRNA­treated mice with HBV infection and liver fibrosis using isobaric tags for relative and absolute quantitation (iTRAQ)­based quantitative proteomics and to elucidate the underlying antifibrotic mechanisms. In total 2,743 proteins were recognized by iTRAQ­based quantitative proteomics analysis. Gene Ontology analysis revealed that the differentially expressed proteins mostly participated in peptide metabolism in the biological process category, cytosolic ribosomes in the cell component category, and structural constituents of ribosomes in the molecular function category. Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that oxidative stress and the peroxisome proliferator­activated receptor (PPAR) signaling pathway were activated after treatment. Verification studies revealed that AAV­shRNAs inhibited hepatic stellate cell activation and inflammation by suppressing nuclear factor­κB p65 phosphorylation and α­smooth muscle actin expression via upregulation of PPAR­Î³. Hepatocytes steatosis was also decreased by activating the PPAR signaling pathway and improving lipid metabolism. The expression level of TGF­ß was decreased due to upregulation of PPAR­Î³ expression and direct inhibition using AAV­shRNA targeting TGF­ß. TGF­ß­induced oxidative stress was suppressed by increasing glutathione S­transferase Pi 1 and reducing peroxiredoxin 1. Collectively, the present results indicated that AAV­shRNAs were effective in modulating liver fibrosis by reducing oxidative stress, inflammation and activating the PPAR signaling pathway.

Atorvastatin and Vitamin E Accelerates NASH Resolution by Dietary Intervention in a Preclinical Guinea Pig Model.

Despite affecting millions of patients worldwide, no pharmacological treatment has yet proved effective against non-alcoholic steatohepatitis (NASH) induced liver fibrosis. Current guidelines recommend lifestyle modifications including reductions in dietary energy intake. Recently, therapy with atorvastatin and vitamin E (vitE) has been recommended, although clinical studies on the resolution of hepatic fibrosis are inconclusive. Targeting NASH-induced hepatic end-points, this study evaluated the effects of atorvastatin and vitE alone or in combination with a dietary intervention in the guinea pig NASH model. Guinea pigs (n = 72) received 20 weeks of high fat feeding before allocating to four groups: continued HF feeding (HF), HF diet with atorvastatin and vitE (HF+), low-fat diet (LF) and low-fat with atorvastatin and vitE (LF+), for four or eight weeks of intervention. Both LF and LF+ decreased liver weight, cholesterol and plasma dyslipidemia. LF+ further improved hepatic histopathological hallmarks (p < 0.05), liver injury markers aspartate aminotransferase (AST) and alanine aminotransferase (ALT) (p < 0.05) and reduced the expression of target genes of hepatic inflammation and fibrosis (p < 0.05), underlining an increased effect on NASH resolution in this group. Collectively, the data support an overall beneficial effect of diet change, and indicate that atorvastatin and vitE therapy combined with a diet change act synergistically in improving NASH-induced endpoints.

Relaxin gene delivery mitigates liver metastasis and synergizes with check point therapy.

Activated hepatic stellate cell (aHSC)-mediated liver fibrosis is essential to the development of liver metastasis. Here, we discover intra-hepatic scale-up of relaxin (RLN, an anti-fibrotic peptide) in response to fibrosis along with the upregulation of its primary receptor (RXFP1) on aHSCs. The elevated expression of RLN serves as a natural regulator to deactivate aHSCs and resolve liver fibrosis. Therefore, we hypothesize this endogenous liver fibrosis repair mechanism can be leveraged for liver metastasis treatment via enforced RLN expression. To validate the therapeutic potential, we utilize aminoethyl anisamide-conjugated lipid-calcium-phosphate nanoparticles to deliver plasmid DNA encoding RLN. The nanoparticles preferentially target metastatic tumor cells and aHSCs within the metastatic lesion and convert them as an in situ RLN depot. Expressed RLN reverses the stromal microenvironment, which makes it unfavorable for established liver metastasis to grow. In colorectal, pancreatic, and breast cancer liver metastasis models, we confirm the RLN gene therapy results in significant inhibition of metastatic progression and prolongs survival. In addition, enforced RLN expression reactivates intra-metastasis immune milieu. The combination of the RLN gene therapy with PD-L1 blockade immunotherapy further produces a synergistic anti-metastatic efficacy. Collectively, the targeted RLN gene therapy represents a highly efficient, safe, and versatile anti-metastatic modality, and is promising for clinical translation.

Functionalized cerium oxide nanoparticles mitigate the oxidative stress and pro-inflammatory activity associated to the portal vein endothelium of cirrhotic rats.

BACKGROUND AND AIMS: The occurrence of endothelial alterations in the liver and in the splanchnic vasculature of cirrhotic patients and experimental models of liver diseases has been demonstrated. However, the pathological role of the portal vein endothelium in this clinical context is scarcely studied and, therefore, deserves attention. In this context, we aimed to investigate whether pathological endothelial activation occurs in the portal vein of cirrhotic rats. METHODS: Cirrhosis was induced in wistar rats by CCl4 inhalation. We generated immortalized endothelial cells from the portal vein of control (CT-iPVEC) and cirrhotic rats (CH-iPVEC) by retroviral transduction of the SV40 T antigen. We assessed differential gene expression and intracellular reactive oxygen species (ROS) levels in iPVECs and in portal veins of control and cirrhotic rats. Finally, we assessed the therapeutic effectiveness of cerium oxide nanoparticles (CeO2NP) on reversing PVEC activation and macrophage polarization. RESULTS: CH-iPVECs overexpressed collagen-I, endothelin-1, TIMP-1, TIMP-2, IL-6 and PlGF genes. These results were consistent with the differential expression showed by whole portal veins from cirrhotic rats. In addition, CH-iPVECs showed a significant increase in intracellular ROS and the capacity of potentiating M1 polarization in macrophages. The treatment of CH-iPVECs with CeO2NPs blocked intracellular ROS formation and IL-6 and TIMP-2 gene overexpression. In agreement with the in vitro results, the chronic treatment of cirrhotic rats with CeO2NPs also resulted in the blockade of both ROS formation and IL-6 gene overexpression in whole portal veins. CONCLUSIONS: Endothelial cells from portal vein of cirrhotic rats depicted an abnormal phenotype characterized by a differential gene expression and the induction of M1 polarization in macrophages. We identified the excess of intracellular reactive oxygen species (ROS) as a major contributor to this altered phenotype. In addition, we demonstrated the utility of the nanomaterial cerium oxide as an effective antioxidant capable of reverse some of these pathological features associated with the portal vein in the cirrhosis condition.

[Effect of bone marrow mesenchymal stem cell transplantation on CCl4-induced liver injury in rats and intervention effects of Yiguanjian].

The aim of this paper was to observe the function of bone marrow mesenchymal stem cell (BMSC) transplantation in process of liver injury induced by carbon tetrachloride (CCl4) in vivo and the intervention effect of Yiguanjian (YGJ), a compound of Chinese herbal medicine. Wistar rats were randomly divided into five groups: normal group, model group, cell transplantation (CT) group, YGJ group and cell transplantation plus Yiguanjian (CTY) group. Liver injury was induced through subcutaneous injection with CCl4 at a dose of 3 mL·kg⁻¹ body weight for 4 weeks, twice a week. They were injected for a total of 9 times. After the first injection with CCl4, rats in the CT group and CTY group were injected with the third-generation BMSCs at dose 1×106 (suspended in 1 mL saline solution) via tail vein. Rats in the YGJ and CTY groups were also intragastrically administered with Yiguanjian once a day. Rat serum ALT and AST activities were increased significantly on the second day after injection with CCl4, while BMSC transplantation and Yiguanjian decreased their activities. After 4 weeks of injection with CCl4, serum ALT, AST and γ-GT activities, and serum TNF-α and IL-6 expressions were increased, while TBIL were decreased in model rats compared with normal rats. Meanwhile, liver cells edema, plasmatic loose, and numerous lipid droplets were observed in rats of the model group. BMSC transplantation aggravated liver injury compared with model rats, which was manifested by decreasing SOD activity, increased MDA, TG, TNF-α and IL-6 levels, and aggravated necrosis level of hepatocytes, fusion of lipid droplets, and collagen deposition in liver tissue. Yiguanjian decreased liver injury induced by CCl4 alone and CCl4 plus BMSC transplantation. SRY gene in situ hybridization method was used to detect the positive SRY expressions in heart, liver, spleen, lung and kidney, especially in liver, while Yiguangjian decreased liver SRY expression. Wnt and ß-catenin showed high expressions in rats of normal group, which were decreased significantly in rats of models group, while Yiguanjian increased their expressions. In conclusion, BMSC transplantation could exacerbate liver injury, while Yiguanjian could protect liver injury induced by CCl4 and BMSC transplantation, which was related to decreasing the homing of BMSCs to liver and up-regulating Wnt/ß-catenin signaling pathway.

Yiguanjian decoction enhances fetal liver stem/progenitor cell-mediated repair of liver cirrhosis through regulation of macrophage activation state.

AIM: To investigate whether Yiguanjian decoction (YGJ) has an anti-liver cirrhotic effect and whether it regulates hepatic stem cell differentiation. METHODS: A rat model of liver cirrhosis was established via subcutaneous injection of carbon tetrachloride (CCl4) for 8 wk. From the beginning of the ninth week, the rats received 2-acetylaminofluorene (2-AAF) by oral gavage and a DLK-1+ fetal liver stem/progenitor cell (FLSPC) transplant or an FLSPC transplant in combination with YGJ treatment for 4 wk. In vitro, lipopolysaccharide (LPS)-activated macrophages were co-cultured with WB-F344 cells, and the differentiation of WB-F344 cells was observed in the presence and absence of YGJ treatment. RESULTS: FLSPC transplantation improved liver function and histopathology, and inhibited the activation of the non-canonical Wnt signaling pathway, while activating the canonical Wnt signaling pathway. YGJ enhanced the therapeutic effects of FLSPCs and also promoted the liver regeneration differentiation of FLSPCs into hepatocytes. In vitro, LPS-activated macrophages promoted the differentiation of WB-F344 cells into myofibroblasts, and the canonical Wnt signaling was inhibited while the non-canonical Wnt signaling was activated in WB-F344 cells. YGJ suppressed the activation of macrophages and then inhibited non-canonical Wnt signaling and promoted canonical Wnt signaling. CONCLUSION: YGJ enhances FLSPC-mediated repair of liver cirrhosis through regulation of macrophage activation state, and YGJ in combination with stem cell transplantation may be a suitable treatment for end-stage liver cirrhosis.

Preclinical safety evaluation of hepatic arterial infusion of oncolytic poxvirus.

PURPOSE: Oncolytic poxvirus has shown promise in treating various solid tumors, such as liver cancer, and administration of oncolytic poxvirus via the hepatic artery may provide more survival benefits than other routes of administration. However, there is a lack of safety information to guide the application of hepatic arterial infusion (HAI) of oncolytic poxvirus in human studies. To investigate the acute and chronic toxicity of HAI administration of oncolytic poxvirus in animals and provide safety information for future human studies. METHODS: VVtk-, a vaccinia poxvirus with inactivated thymidine kinase gene, was administered via HAI to rabbits with normal liver function under angiography (1×108 or 1×109 pfu), and rats with N-nitrosomorpholine-induced precancerous liver cirrhosis under open surgery (1×108 pfu). Body weights and survival were monitored and blood samples were collected for hematological and biochemical tests. Distribution of A56 (a specific marker for poxvirus infection) in rabbit organs was evaluated using immunofluorescence assays. RESULTS: HAI of high doses of VVtk- did not cause any acute or chronic changes in body weight, survival or in biochemical, hematological tests in the 2 animal models, and none of the changes showed dose dependency (in rabbit study), or were influenced by liver cirrhosis (in rat study). A56 was not detected in any of the major rabbit organs. CONCLUSION: HAI may provide a safe alternative route of oncolytic poxvirus administration for human studies.

Gene activation of CEBPA using saRNA: preclinical studies of the first in human saRNA drug candidate for liver cancer.

Liver diseases are a growing epidemic worldwide. If unresolved, liver fibrosis develops and can lead to cirrhosis and clinical decompensation. Around 5% of cirrhotic liver diseased patients develop hepatocellular carcinoma (HCC), which in its advanced stages has limited therapeutic options and negative survival outcomes. CEPBA is a master regulator of hepatic function where its expression is known to be suppressed in many forms of liver disease including HCC. Injection of MTL-CEBPA, a small activating RNA oligonucleotide therapy (CEBPA-51) formulated in liposomal nanoparticles (NOV340- SMARTICLES) upregulates hepatic CEBPA expression. Here we show how MTL-CEBPA therapy promotes disease reversal in rodent models of cirrhosis, fibrosis, hepatosteatosis, and significantly reduces tumor burden in cirrhotic HCC. Restoration of liver function markers were observed in a carbon-tetrachloride-induced rat model of fibrosis following 2 weeks of MTL-CEBPA therapy. At 14 weeks, animals showed reduction in ascites and enhanced survival rates. MTL-CEBPA reversed changes associated with hepatosteatosis in non-alcoholic methionine and cholic-deficient diet-induced steaotic liver disease. In diethylnitrosamine induced cirrhotic HCC rats, MTL-CEBPA treatment led to a significant reduction in tumor burden. The data included here and the rapid adoption of MTL-CEBPA into a Phase 1 study may lead to new therapeutic oligonucleotides for undruggable diseases.

Mesenchymal Stem Cells with Enhanced Bcl-2 Expression Promote Liver Recovery in a Rat Model of Hepatic Cirrhosis.

BACKGROUND/AIMS: Mesenchymal stem cell (MSC) transplantation has emerged as an option for the treatment of chronic hepatic cirrhosis, while its therapeutic efficacy could be improved. The bcl-2 gene is anti-apoptotic and can help cell survival and proliferation. Therefore, we explored whether transplanted MSCs with enhanced bcl-2 expression may be beneficial in the treatment of experimental cirrhosis in rats. METHODS: MSCs were isolated from rat bone marrow, expanded in vitro and transfected with adeno-associated virus (AAV) engineered the bcl-2 gene (AAV-bcl-2). Rats with cirrhosis induced by carbon tetrachloride (CCl4) were treated with AAV-bcl-2 infected BMSCs-AAV-bcl-2, with the cells traced in vivo post transplantation. Liver pathology and function were evaluated 7, 14, 21, and 28 days post transplantation, respectively. RESULTS: On day 7 post transplantation, the infused AAV-bcl-2 had integrated into the hepatocyte-like cells (HLCs) that expressed albumin (ALB), Cytokeratin 18 (CK18), and hepatocytes nuclear factor 4a (HNF4a). On day 28 post transplantation, rats in the cirrhosis + BMSCs-AAV-bcl-2 group showed the most dense HLCs, highest mRNA and protein levels of ALB, CK18, and HNF4a, compared to the other groups. Their liver function recovered most rapidly in 4 week observation, while histological sign of cirrhosis remained at the end of this period. CONCLUSION: BMSCs over expressing bcl-2 gene showed better survival, and enhanced the differentiation into hepatocytes-like cells, and appeared to promote the recovery of liver function in rats with experimental cirrhosis.

Hepcidin inhibits Smad3 phosphorylation in hepatic stellate cells by impeding ferroportin-mediated regulation of Akt.

Hepatic stellate cell (HSC) activation on liver injury facilitates fibrosis. Hepatokines affecting HSCs are largely unknown. Here we show that hepcidin inhibits HSC activation and ameliorates liver fibrosis. We observe that hepcidin levels are inversely correlated with exacerbation of fibrosis in patients, and also confirm the relationship in animal models. Adenoviral delivery of hepcidin to mice attenuates liver fibrosis induced by CCl4 treatment or bile duct ligation. In cell-based assays, either hepcidin from hepatocytes or exogenous hepcidin suppresses HSC activation by inhibiting TGFß1-mediated Smad3 phosphorylation via Akt. In activated HSCs, ferroportin is upregulated, which can be prevented by hepcidin treatment. Similarly, ferroportin knockdown in HSCs prohibits TGFß1-inducible Smad3 phosphorylation and increases Akt phosphorylation, whereas ferroportin over-expression has the opposite effect. HSC-specific ferroportin deletion also ameliorates liver fibrosis. In summary, hepcidin suppresses liver fibrosis by impeding TGFß1-induced Smad3 phosphorylation in HSCs, which depends on Akt activated by a deficiency of ferroportin.

Simultaneous Administration of ADSCs-Based Therapy and Gene Therapy Using Ad-huPA Reduces Experimental Liver Fibrosis.

BACKGROUND AND AIMS: hADSCs transplantation in cirrhosis models improves liver function and reduces fibrosis. In addition, Ad-huPA gene therapy diminished fibrosis and increased hepatocyte regeneration. In this study, we evaluate the combination of these therapies in an advanced liver fibrosis experimental model. METHODS: hADSCs were expanded and characterized before transplantation. Ad-huPA was simultaneously administrated via the ileac vein. Animals were immunosuppressed by CsA 24 h before treatment and until sacrifice at 10 days post-treatment. huPA liver expression and hADSCs biodistribution were evaluated, as well as the percentage of fibrotic tissue, hepatic mRNA levels of Col-αI, TGF-ß1, CTGF, α-SMA, PAI-I, MMP2 and serum levels of ALT, AST and albumin. RESULTS: hADSCs homed mainly in liver, whereas huPA expression was similar in Ad-huPA and hADSCs/Ad-huPA groups. hADSCs, Ad-huPA and hADSCs/Ad-huPA treatment improves albumin levels, reduces liver fibrosis and diminishes Collagen α1, CTGF and α-SMA mRNA liver levels. ALT and AST serum levels showed a significant decrease exclusively in the hADSCs group. CONCLUSIONS: These results showed that combinatorial effect of cell and gene-therapy does not improve the antifibrogenic effects of individual treatments, whereas hADSCs transplantation seems to reduce liver fibrosis in a greater proportion.

A single adenovirus-mediated relaxin delivery attenuates established liver fibrosis in rats.

BACKGROUND: Liver fibrosis is characterized by an excess accumulation and repressed degradation of extracellular matrix. Although methods of alleviating already established liver fibrosis have scarcely been reported, continuous relaxin (RLX) infusion has demonstrated some promising results. In the present study, we investigated whether a single adenoviral delivery of RLX would attenuate established liver fibrosis in rats. METHODS: Rats were given thioacetamide (TAA) for 8 weeks and infected once with either RLX-expressing adenovirus (TAA + RLX) or control virus (TAA + Vector) via the tail vein. They were sacrificed either 3 days or 3 weeks after adenovirus infection. RESULTS: Morphometric analysis of picrosirius red stained area demonstrated that the TAA + RLX group had significantly decreased fibrosis at week 3 when liver fibrosis of the TAA + Vector group remained unchanged. Although the liver and serum RLX levels were elevated on day 3 and reversed by week 3, expression of RLX receptor (Rxfp1; relaxin-like family peptide receptor-1) in TAA + RLX rats was sustained and elevated. The production of tissue cyclic adenosine monophosphate, which is a second messenger of activated Rxfp1, was still enhanced in the TAA + RLX group by week 3. Expression of lysyl oxidase homolog 2, which contributes to collagen cross-linking and is up-regulated by TAA treatment, was significantly decreased by week 3 in the TAA + RLX group. Expression of tissue inhibitor of metalloprotiase-2 was alleviated in the TAA + RLX group at week 3, whereas that of TAA + Vector rats was still elevated. CONCLUSIONS: A single adenoviral delivery of RLX in the liver attenuated established hepatic fibrosis by suppressing collagen cross-linking and enhancing collagen degradation.

Liver Bid suppression for treatment of fibrosis associated with non-alcoholic steatohepatitis.

BACKGROUND & AIMS: Liver fibrosis is the most worrisome feature of non-alcoholic steatohepatitis (NASH). Growing evidence supports a link between hepatocyte apoptosis and liver fibrogenesis. Our aim was to determine the therapeutic efficacy and safety of liver Bid, a key pro-apoptotic molecule, suppression using RNA interference (RNAi) for the treatment of fibrosis. METHODS: First, we optimized the delivery system for Bid siRNA in mice using ten different stealth RNAi siRNAs and two lipid formulations -Invivofectamine2.0 and a newly developed Invivofectamine3.0 - that have been designed for high efficacy accumulation in the liver, assessed via real-time PCR of Bid mRNA. Next, C57BL/6 mice were placed on a choline-deficient L-amino acid defined (CDAA) diet. After 19weeks of the CDAA diet, a time point that results in severe fibrotic NASH, mice were injected with the selected Bid siRNA-Invivofectamine3.0 biweekly for three weeks. Additionally hepatocyte-specific Bid deficient (Bid(Δhep)) mice were placed on CDAA diet for 20weeks. RESULTS: A maximum Bid knockdown was achieved at 1.5mg/kg siRNA with Invivofectamine3.0, whereas it was at 7mg/kg with Invivofectamine2.0. In NASH mice, after 3weeks of treatment, BID protein was reduced to 10% and this was associated with an improvement in liver fibrosis and inflammation associated with a marked reduction in TUNEL positive cells, caspase 3 activation, and a reduction in mitochondrial BAX and BAK. Bid(Δhep) mice showed similar protection from fibrotic changes. CONCLUSION: Our data demonstrate that liver Bid suppression by RNAi technology, as well as hepatocyte-specific Bid deficiency, improves liver fibrosis coupled with a reduction of inflammation in experimental NASH. These findings are consistent with existing evidence that hepatocyte apoptosis triggers hepatic stellate cell activation and liver fibrosis and suggest that Bid inhibition may be useful as an antifibrotic NASH therapy.

Experimental models of liver fibrosis.

Hepatic fibrosis is a wound healing response to insults and as such affects the entire world population. In industrialized countries, the main causes of liver fibrosis include alcohol abuse, chronic hepatitis virus infection and non-alcoholic steatohepatitis. A central event in liver fibrosis is the activation of hepatic stellate cells, which is triggered by a plethora of signaling pathways. Liver fibrosis can progress into more severe stages, known as cirrhosis, when liver acini are substituted by nodules, and further to hepatocellular carcinoma. Considerable efforts are currently devoted to liver fibrosis research, not only with the goal of further elucidating the molecular mechanisms that drive this disease, but equally in view of establishing effective diagnostic and therapeutic strategies. The present paper provides a state-of-the-art overview of in vivo and in vitro models used in the field of experimental liver fibrosis research.

Splenectomy enhances the therapeutic effect of adipose tissue-derived mesenchymal stem cell infusion on cirrhosis rats.

BACKGROUND & AIMS: Clinical studies suggest that splenectomy improves liver function in cirrhotic patients, but the influence of splenectomy on stem cell transplantation is poorly understood. This study investigated the effect of splenectomy on stem cell infusion and elucidated its mechanism. METHODS: Rat adipose tissue-derived mesenchymal stem cells were infused into cirrhosis rats with or without splenectomy, followed by the assessment of the in vivo distribution of stem cells and pathological changes. Stromal cell-derived factor-1 and hepatocyte growth factor expression were also investigated in splenectomized cirrhosis patients and rats. RESULTS: Splenectomy, prior to cell infusion, improved liver function and suppressed fibrosis progression more efficiently than cell infusion alone in the experimental cirrhosis model. Stromal cell-derived factor-1 and hepatocyte growth factor levels after splenectomy were increased in patients and rats. These upregulated cytokines significantly facilitated stem cell motility, migration and proliferation in vitro. C-X-C chemokine receptor type 4 neutralization weakened the promotion of cell migration by these cytokines. The infused cells integrated into liver fibrosis septa and participated in regeneration more efficiently in splenectomized rats. Direct coculture with stem cells led to inhibition of hepatic stellate cell proliferation. In addition, hepatocyte growth factor induced hepatic stellate cell apoptosis via the c-jun N-terminal kinase-p53 pathway. CONCLUSIONS: Splenectomy prior to cell infusion enhanced the therapeutic effect of stem cells on cirrhosis, which involved upregulation of stromal cell-derived factor-1 and hepatocyte growth factor after splenectomy.

Adenoviral delivery of truncated MMP-8 fused with the hepatocyte growth factor mutant 1K1 ameliorates liver cirrhosis and promotes hepatocyte proliferation.

Liver cirrhosis is a chronic liver disease caused by chronic liver injury, which activates hepatic stellate cells (HSCs) and the secretion of extracellular matrix (ECM). Cirrhosis accounts for an extensive level of morbidity and mortality worldwide, largely due to lack of effective treatment options. In this study, we have constructed a fusion protein containing matrix metal-loproteinase 8 (MMP-8) and the human growth factor mutant 1K1 (designated cMMP8-1K1) and delivered it into hepatocytes and in vivo and in cell culture via intravenous injection of fusion protein-harboring adenovirus. In doing so, we found that the cMMP8-1K1 fusion protein promotes the proliferation of hepatocytes, likely resulting from the combined inhibition of type I collagen secretion and the degradation of the ECM in the HSCs. This fusion protein was also observed to ameliorate liver cirrhosis in our mouse model. These changes appear to be linked to changes in downstream gene expression. Taken together, these results suggest a possible strategy for the treatment of liver cirrhosis and additional work is warranted.