Mesenchymal stem cell therapy for cirrhosis: Present and future perspectives

Long-term expanded hepatic progenitor cells ameliorate D-GalN/LPS-induced acute liver failure through repolarizing M1 macrophage to M2-Like phenotype via activation of the IL-10/JAK2/STAT3 signaling pathway

Acute liver failure (ALF) is a devastating liver disease characterized by the rapid deterioration of hepatocytes, which causes a series of clinical complications, including hepatic dysfunction, coagulopathy, encephalopathy, and multiorgan failure. Cell-based therapy is a promising alternative as it can bridge patients until their livers regenerate, releasing immunomodulatory molecules to suppress inflammation. This study reports an iPSCs-derived long-term expanded hepatic progenitor cell (LTHepPCs), which can differentiate into hepatocyte-like cells (HLCs) in vivo. When introduced into drug-induced ALF models, LTHepPCs mitigate liver damage by modulating the local immune microenvironment. This is achieved by shifting macrophages/Kupffer cells towards an anti-inflammatory state, resulting in a decrease in the expression of inflammatory cytokines such as TNF-a, IL-1β, and IL-8, and an increase in the expression of anti-inflammatory cytokines such as IL-10 and ARG-1. In vitro co-culturing of THP-1 or mBMDMs with LTHepPCs suggested that LTHepPCs could activate the anti-inflammatory state of macrophages/Kupffer cells via the IL-10/JAK2/STAT3 signaling pathway. Therefore, LTHepPC transplantation is a promising therapy for ALF patients.

Efficacy of stem cell therapy in patients with chronic liver disease: an umbrella review of systematic reviews

BACKGROUND

Stem cell therapy offers promising benefits like modulating immune responses, reducing inflammation, and aiding liver regeneration. This umbrella review seeks to compile evidence from systematic reviews to assess the efficacy of stem cell therapy for improving liver function and survival rates in chronic liver disease patients.

METHODS

We searched electronic databases up to February 15, 2024. The selection process focused on systematic reviews comparing stem cell therapy with standard care or a placebo. The primary outcomes evaluated were changes in liver enzymes, the Model for End-Stage Liver Disease score, and survival rates. Nested Knowledge software was utilized for screening and data extraction. All statistical analyses were performed using R software, version 4.3.

RESULTS

Our umbrella review included 28 systematic reviews. The meta-analysis showcased a notable improvement in survival rates with a pooled relative risk of 1.487 [95% confidence interval (CI): 1.281-1.727). In nonrandomized studies, albumin levels exhibited a standardized mean difference (SMD) of 0.786 (95% CI: 0.368-1.204), indicating positive therapeutic effects. For alanine aminotransferase, the meta-analysis revealed a decrease in levels with an SMD of -0.499 (95% CI: -0.834 to -0.164), and for aspartate aminotransferase, an overall SMD of -0.362 (95% CI: -0.659 to -0.066) was observed, suggesting hepatoprotective effects. No significant changes were observed in total bilirubin levels and Model for End-Stage Liver Disease scores in randomized controlled trials.

CONCLUSION

Stem cell therapy exhibits potential as a novel treatment for chronic liver diseases, as it has demonstrated improvements in survival rates and certain liver function markers. More high-quality randomized controlled trials are needed in the future to fully ascertain the efficacy of stem cell therapy in this patient population.

Role of TGF-β and p38 MAPK in TSG-6 Expression in Adipose Tissue-Derived Stem Cells In Vitro and In Vivo

Mesenchymal stem cells (MSCs) regulate immune cell activity by expressing tumor necrosis factor-α (TNF-α)-stimulated gene 6 (TSG-6) in inflammatory environments; however, whether anti-inflammatory responses affect TSG-6 expression in MSCs is not well understood. Therefore, we investigated whether transforming growth factor-β (TGF-β) regulates TSG-6 expression in adipose tissue-derived stem cells (ASCs) and whether effective immunosuppression can be achieved using ASCs and TGF-β signaling inhibitor A83-01. TGF-β significantly decreased TSG-6 expression in ASCs, but A83-01 and the p38 inhibitor SB202190 significantly increased it. However, in septic C57BL/6 mice, A83-01 further reduced the survival rate of the lipopolysaccharide (LPS)-treated group and ASC transplantation did not improve the severity induced by LPS. ASC transplantation alleviated the severity of sepsis induced by LPS+A83-01. In co-culture of macrophages and ASCs, A83-01 decreased TSG-6 expression whereas A83-01 and SB202190 reduced Cox-2 and IDO-2 expression in ASCs. These results suggest that TSG-6 expression in ASCs can be regulated by high concentrations of pro-inflammatory cytokines in vitro and in vivo, and that A83-01 and SB202190 can reduce the expression of immunomodulators in ASCs. Therefore, our data suggest that co-treatment of ASCs with TGF-β or p38 inhibitors is not adequate to modulate inflammation.

Generation of Fibrotic Liver Organoids Using Hepatocytes, Primary Liver Sinusoidal Endothelial Cells, Hepatic Stellate Cells, and Macrophages

Liver organoids generated with single or multiple cell types have been used to investigate liver fibrosis development, toxicity, pathogenesis, and drug screening. However, organoid generation is limited by the availability of cells isolated from primary tissues or differentiated from various stem cells. To ensure cell availability for organoid formation, we investigated whether liver organoids could be generated with cell-line-based Huh-7 hepatocellular carcinoma cells, macrophages differentiated from THP-1 monocytes, and LX-2 hepatic stellate cells (HSCs) and primary liver sinusoidal endothelial cells (LSECs). In liver organoids, hepatocyte-, LSEC-, macrophage-, and HSC-related gene expression increased relative to that in two-dimensional (2D)-cultured Huh-7/LSEC/THP-1/LX-2 cells without Matrigel. Thioacetamide (TAA) increased α-smooth muscle actin expression in liver organoids but not in 2D-cultured cells, whereas in TAA-treated organoids, the expression of hepatic and LSEC markers decreased and that of macrophage and HSC markers increased. TAA-induced fibrosis was suppressed by treatment with N-acetyl-L-cysteine or tumor-necrosis-factor-stimulated gene 6 protein. The results showed that liver toxicants could induce fibrotic and inflammatory responses in liver organoids comprising Huh-7/LSEC/macrophages/LX-2 cells, resulting in fibrotic liver organoids. We propose that cell-line-based organoids can be used for disease modeling and drug screening to improve liver fibrosis treatment.

Efficacy and safety of mesenchymal stem cell therapy in liver cirrhosis: a systematic review and meta-analysis

AIM

Although the efficacy and safety of mesenchymal stem cell therapy for liver cirrhosis have been demonstrated in several studies. Clinical cases of mesenchymal stem cell therapy for patients with liver cirrhosis are limited and these studies lack the consistency of treatment effects. This article aimed to systematically investigate the efficacy and safety of mesenchymal stem cells in the treatment of liver cirrhosis.

METHOD

The data source included PubMed/Medline, Web of Science, EMBASE, and Cochrane Library, from inception to May 2023. Literature was screened by the PICOS principle, followed by literature quality evaluation to assess the risk of bias. Finally, the data from each study's outcome indicators were extracted for a combined analysis. Outcome indicators of the assessment included liver functions and adverse events. Statistical analysis was performed using Review Manager 5.4.

RESULTS

A total of 11 clinical trials met the selection criteria. The pooled analysis' findings demonstrated that both primary and secondary indicators had improved. Compared to the control group, infusion of mesenchymal stem cells significantly increased ALB levels in 2 weeks, 1 month, 3 months, and 6 months, and significantly decreased MELD score in 1 month, 2 months, and 6 months, according to a subgroup analysis using a random-effects model. Additionally, the hepatic arterial injection favored improvements in MELD score and ALB levels. Importantly, none of the included studies indicated any severe adverse effects.

CONCLUSION

The results showed that mesenchymal stem cell was effective and safe in the treatment of liver cirrhosis, improving liver function (such as a decrease in MELD score and an increase in ALB levels) in patients with liver cirrhosis and exerting protective effects on complications of liver cirrhosis and the incidence of hepatocellular carcinoma. Although the results of the subgroup analysis were informative for the selection of mesenchymal stem cells for clinical treatment, a large number of high-quality randomized controlled trials validations are still needed.

Activated Natural Killer Cell Inoculation Alleviates Fibrotic Liver Pathology in a Carbon Tetrachloride-Induced Liver Cirrhosis Mouse Model

Activated hepatic stellate cells (HSCs) play a detrimental role in liver fibrosis progression. Natural killer (NK) cells are known to selectively recognize abnormal or transformed cells via their receptor activation and induce target cell apoptosis and, therefore, can be used as a potential therapeutic strategy for liver cirrhosis. In this study, we examined the therapeutic effects of NK cells in the carbon tetrachloride (CCl₄)-induced liver cirrhosis mouse model. NK cells were isolated from the mouse spleen and expanded in the cytokine-stimulated culture medium. Natural killer group 2, member D (NKG2D)-positive NK cells were significantly increased after a week of expansion in culture. The intravenous injection of NK cells significantly alleviated liver cirrhosis by reducing collagen deposition, HSC marker activation, and macrophage infiltration. For in vivo imaging, NK cells were isolated from codon-optimized luciferase-expressing transgenic mice. Luciferase-expressing NK cells were expanded, activated and administrated to the mouse model to track them. Bioluminescence images showed increased accumulation of the intravenously inoculated NK cells in the cirrhotic liver of the recipient mouse. In addition, we conducted QuantSeq 3' mRNA sequencing-based transcriptomic analysis. From the transcriptomic analysis, 33 downregulated genes in the extracellular matrix (ECM) and 41 downregulated genes involved in the inflammatory response were observed in the NK cell-treated cirrhotic liver tissues from the 1532 differentially expressed genes (DEGs). This result indicated that the repetitive administration of NK cells alleviated the pathology of liver fibrosis in the CCl₄-induced liver cirrhosis mouse model via anti-fibrotic and anti-inflammatory mechanisms. Taken together, our research demonstrated that NK cells could have therapeutic effects in a CCl₄-induced liver cirrhosis mouse model. In particular, it was elucidated that extracellular matrix genes and inflammatory response genes, which were mainly affected after NK cell treatment, could be potential targets.

Mesenchymal stem cells-based therapy in liver diseases

Multiple immune cells and their products in the liver together form a complex and unique immune microenvironment, and preclinical models have demonstrated the importance of imbalances in the hepatic immune microenvironment in liver inflammatory diseases and immunocompromised liver diseases. Various immunotherapies have been attempted to modulate the hepatic immune microenvironment for the purpose of treating liver diseases. Mesenchymal stem cells (MSCs) have a comprehensive and plastic immunomodulatory capacity. On the one hand, they have been tried for the treatment of inflammatory liver diseases because of their excellent immunosuppressive capacity; On the other hand, MSCs have immune-enhancing properties in immunocompromised settings and can be modified into cellular carriers for targeted transport of immune enhancers by genetic modification, physical and chemical loading, and thus they are also used in the treatment of immunocompromised liver diseases such as chronic viral infections and hepatocellular carcinoma. In this review, we discuss the immunological basis and recent strategies of MSCs for the treatment of the aforementioned liver diseases. Specifically, we update the immune microenvironment of the liver and summarize the distinct mechanisms of immune microenvironment imbalance in inflammatory diseases and immunocompromised liver diseases, and how MSCs can fully exploit their immunotherapeutic role in liver diseases with both immune imbalance patterns.

Transplantation of Wharton's jelly mesenchymal stem cells encapsulated with Hydroactive® Gel promotes diabetic wound antifibrotic healing in type 2 diabetic rats

Diabetic cutaneous ulcers (DCU) are a complication for diabetes patients, mostly occurring in the foot and causing non-healing diabetic foot ulcers. Mesenchymal stem cell (MSC)-based therapy is currently being investigated as a therapeutic avenue for chronic diabetic ulcers. However, poor engraftment, short retention, and low survival still limit the treatment effectiveness. Hydroactive® Gel is a sterile transparent gel made of natural hydrocolloid, which has been widely used for wound management. Whether transplantation of Wharton's jelly mesenchymal stem cells (WJMSCs) encapsulated with Hydroactive® Gel is helpful to diabetic ulcers wound healing remains to be explored. The biocompatibility experiments showed that WJMSCs embedded in Hydroactive® Gel did not influence the cell viability, survival, proliferation, and apoptosis of WJMSCs in vitro. RNA-seq results also implied that Hydroactive® Gel + WJMSCs transplantation activated the "cytokine-cytokine receptor interaction", "mononuclear cell differentiation", "regulation of cell-cell adhesion", and "chemokine receptor activity" to accelerate the inflammatory reaction and epidermis regeneration in diabetic wounds. Histological analysis results demonstrated that Hydroactive® Gel encapsulated WJMSCs transplantation promoted diabetic wound healing and regeneration, indicating improved dermis regeneration, sebaceous gland formation, and type III collagen fiber deposition. Besides, immunohistochemical analysis results showed that Hydroactive® Gel + WJMSCs transplantation also facilitated the transformation of pro-inflammatory M1 macrophages to anti-inflammatory M2 macrophages, cell proliferation, and neovascularization at the wound site. Hydroactive® Gel encapsulation further prolonged the retention time of WJMSCs at the diabetic wound site. Above all, Hydroactive® Gel accelerates WJMSCs-mediated diabetic wound healing by promoting macrophage transformation, facilitating cell proliferation and angiogenesis, and prolonging cell retention time. Our findings may potentially provide a useful therapeutic strategy based on the combination of WJMSCs and biomedical materials for patients with diabetic cutaneous ulcers.

Comparative study on effect of mesenchymal stem cells and endothelial progenitor cells on treatment of experimental CCL4-induced liver fibrosis

BACKGROUND

We speculated impacts of BM-MSCs and UC-EPCs on reversal of hepatic injury induced by carbon tetrachloride (CCl4). Fifty adult rats were divided into five groups: control group, CCl4A group, CCl4B group, CCl4/BM-MSCs group and CCl4/UC-EPCs group. Blood samples were driven to measure concentration of albumin and ALT. Quantitative expression of HGF, TGF-β, MMP-2, and VEGF were assessed by PCR. Histological and immunohistochemistry examination of the liver tissue were performed.

RESULTS

There was elevating albumin (p < .05) and reducing ALT (p < .05) concentrations in groups treated with BM-MSCs and UC-EPCs compared to untreated CCL4A&B groups. UC-EPCs treated group have significantly higher MMP-2 and VEGF (p < .01) genes expression than BM-MSCs treated group. Furthermore, UC-EPCs were more valuable than BMMSCs in increasing gene expression of HGF (p < .05) and immunohistochemistry of α-SMA and Ki-67 (p < .01). BM-MSCs have significantly lower TGF-β (p < .00) compared to UC-EPCs.

CONCLUSION

This study highlighted on liver regeneration role of both UC-EPCs and BM-MSCs in liver fibrosis.

Efficacy and Safety of Mesenchymal Stem Cell Transplantation in the Treatment of Autoimmune Diseases (Rheumatoid Arthritis, Systemic Lupus Erythematosus, Inflammatory Bowel Disease, Multiple Sclerosis, and Ankylosing Spondylitis): A Systematic Review and Meta-Analysis of Randomized Controlled Trial

Objective

To evaluate the efficacy and safety of mesenchymal stem cell (MSC) transplantation in the treatment of autoimmune diseases.

Methods

The Chinese and English databases were searched for clinical research on the treatment of autoimmune diseases with mesenchymal stem cells. The search time range is from a self-built database to October 1, 2021. Two reviewers independently screened the literature according to the inclusion and exclusion criteria, extracted data, and evaluated the bias of the included studies. RevMan 5.3 analysis software was used for meta-analysis.

Results

A total of 18 RCTs involving 5 autoimmune diseases were included. The 5 autoimmune disease were rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), inflammatory bowel disease, ankylosing spondylitis, and multiple sclerosis. For RA, the current randomized controlled trials (RCTs) still believe that stem cell transplantation may reduce disease activity, improve the clinical symptoms (such as DAS28), and the percentage of CD4+CD 25+Foxp3+Tregs in the response group increased and the percentage of CD4+IL-17A+Th17 cells decreased. The total clinical effective rate of RA is 54%. For SLE, the results showed that mesenchymal stem cell transplantation may improve SLEDAI [-2.18 (-3.62, -0.75), P = 0.003], urine protein [-0.93 (-1.04, -0.81), P < 0.00001], and complement C3 [0.31 (0.19, 0.42), P < 0.00001]. For inflammatory bowel disease, the results showed that mesenchymal stem cell transplantation may improve clinical efficacy [2.50 (1.07, 5.84), P = 0.03]. For ankylosing spondylitis, MSC treatment for 6 months may increase the total effective rate; reduce erythrocyte sedimentation rate, intercellular adhesion molecules, and serum TNF-α; and improve pain and activity. For multiple sclerosis, the current research results are still controversial, so more RCTs are needed to amend or confirm the conclusions. No obvious adverse events of mesenchymal stem cell transplantation were found in all RCTs.

Conclusion

MSCs have a certain effect on different autoimmune diseases, but more RCTs are needed to further modify or confirm the conclusion.

Recent Advances in Bioengineered Scaffolds for Cutaneous Wound Healing

Wound healing is an evolved dynamic biological process. Though many research and clinical approaches have been explored to restore damaged or diseased skin, the current treatment for deep cutaneous injuries is far from being perfect, and the ideal regenerative therapy remains a significant challenge. Of all treatments, bioengineered scaffolds play a key role and represent great progress in wound repair and skin regeneration. In this review, we focus on the latest advancement in biomaterial scaffolds for wound healing. We discuss the emerging philosophy of designing biomaterial scaffolds, followed by precursor development. We pay particular attention to the therapeutic interventions of bioengineered scaffolds for cutaneous wound healing, and their dual effects while conjugating with bioactive molecules, stem cells, and even immunomodulation. As we review the advancement and the challenges of the current strategies, we also discuss the prospects of scaffold development for wound healing.

Role of the Microenvironment in Mesenchymal Stem Cell-Based Strategies for Treating Human Liver Diseases

Liver disease is a severe health problem that endangers human health worldwide. Mesenchymal stem cell (MSC) therapy is a novel treatment for patients with different liver diseases due to its vast expansion potential and distinctive immunomodulatory properties. Despite several preclinical trials having confirmed the considerable efficacy of MSC therapy in liver diseases, the questionable safety and efficacy still limit its application. As a precursor cell, MSCs can adjust their characteristics in response to the surrounding microenvironment. The microenvironment provides physical and chemical factors essential for stem cell survival, proliferation, and differentiation. However, the mechanisms are still not completely understood. We, therefore, summarized the mechanisms underlying the MSC immune response, especially the interaction between MSCs and the liver microenvironment, discussing how to achieve better therapeutic effects.

The Phosphonate Derivative of C60 Fullerene Induces Differentiation towards the Myogenic Lineage in Human Adipose-Derived Mesenchymal Stem Cells

Inductors of myogenic stem cell differentiation attract attention, as they can be used to treat myodystrophies and post-traumatic injuries. Functionalization of fullerenes makes it possible to obtain water-soluble derivatives with targeted biochemical activity. This study examined the effects of the phosphonate C₆₀ fullerene derivatives on the expression of myogenic transcription factors and myogenic differentiation of human mesenchymal stem cells (MSCs). Uptake of the phosphonate C₆₀ fullerene derivatives in human MSCs, intracellular ROS visualization, superoxide scavenging potential, and the expression of myogenic, adipogenic, and osteogenic differentiation genes were studied. The prolonged MSC incubation (within 7–14 days) with the C₆₀ pentaphoshonate potassium salt promoted their differentiation towards the myogenic lineage. The transcription factors and gene expressions determining myogenic differentiation (MYOD1, MYOG, MYF5, and MRF4) increased, while the expression of osteogenic differentiation factors (BMP2, BMP4, RUNX2, SPP1, and OCN) and adipogenic differentiation factors (CEBPB, LPL, and AP2 (FABP4)) was reduced or did not change. The stimulation of autophagy may be one of the factors contributing to the increased expression of myogenic differentiation genes in MSCs. Autophagy may be caused by intracellular alkalosis and/or short-term intracellular oxidative stress.

Stem Cell Transplant for Advanced Stage Liver Disorders: Current Scenario and Future Prospects

BACKGROUND

Chronic Liver Disorders (CLD), caused by the lifestyle patterns like alcoholism or by non-alcoholic fatty liver disease or because of virus-mediated hepatitis, affect a large population fraction across the world. CLD progresses into end-stage diseases with a high mortality rate. Liver transplant is the only approved treatment available for such end-stage disease patients. However, the number of liver transplants is limited due to the limited availability of suitable donors and the extremely high cost of performing the procedure. Under such circumstances, Stem Cell (SC) mediated liver regeneration has emerged as a potential therapeutic alternative approach.

OBJECTIVE

This review aims to critically analyze the current status and future prospects of stem cellbased interventions for end-stage liver diseases. The clinical studies undertaken, the mechanism underlying therapeutic effects and future directions have been examined.

METHOD

The clinical trial databases were searched at https://clinicaltrials.gov.in and http://www.isrctn.com to identify randomized, non-randomized and controlled studies undertaken with keywords such as "liver disorder and Mesenchymal Stem Cells (MSCs)", "liver cirrhosis and MSCs" and "liver disorder and SCs". Furthermore, https://www.ncbi.nlm.nih.gov/pubmed/ database was also explored with similar keywords for finding the available reports and their critical analyses.

RESULTS

The search results yielded a significant number of studies that used bone marrow-derived stem cells, MSCs and hepatocytes. The studies clearly indicated that SCs play a key role in the hepatoprotection process by some mechanisms involving anti-inflammation, auto-immune-suppression, angiogenesis and anti-apoptosis. Further, studies indicated that SCs derived paracrine factors promote angiogenesis, reduce inflammation and inhibit hepatocyte apoptosis.

CONCLUSION

The SC-based interventions provide a significant improvement in patients with CLD; however, there is a need for randomized, controlled studies with the analysis of a long-term follow-up.

Allogeneic mesenchymal stem cell sheet therapy: A new frontier in drug delivery systems

The evolution of drug discovery exploded in the early 20th century with the advent of critical scientific advancements in organic chemistry, chemical analysis, and purification. Early drug generations focused largely on symptom control and pain management, effective targets for small-molecule drugs. Recently, the attention in drug discovery has shifted to pursuit of radical cures. Cell therapy presents the ideal attributes of a promising new drug, targeting specific tissues based on chemotactic cues and modulating secretion of instructive regenerative molecules in response to dynamic signaling from disease environments. To actuate the therapeutic potential of cell therapy toward worldwide clinical use, cell delivery methods that can effectively localize and engraft mesenchymal stem cells (MSCs) with high disease-site fidelity and enable dynamic MSC bioactive function are paramount. In this review, we discuss the evolution of cell therapies with a focus on stem cell advantages, as well as the limitations to these therapies. This review aims to introduce cell sheet technology as a breakthrough cell therapy with demonstrated therapeutic success across indications for heart, liver, and kidney tissue regeneration. Opportunities and anticipated clinical impacts of cell sheet technology using MSCs are discussed.

sEVs from tonsil-derived mesenchymal stromal cells alleviate activation of hepatic stellate cells and liver fibrosis through miR-486-5p

Mesenchymal stromal cells (MSCs) are considered as a promising therapeutic tool for liver fibrosis, a main feature of chronic liver disease. Because small extracellular vesicles (sEVs) harboring a variety of proteins and RNAs are known to have similar functions with their derived cells, MSC-derived sEVs carry out the regenerative capacities of MSCs. Human tonsil-derived MSCs (T-MSCs) are reported as a novel source of MSCs, but their effects on liver fibrosis remain unclear. In the present study, we investigated the effects of T-MSC-derived sEVs on liver fibrosis. The expression of profibrotic genes decreased in human primary hepatic stellate cells (pHSCs) co-cultured with T-MSCs. Treatment of T-MSC-sEVs inactivated human and mouse pHSCs. Administration of T-MSC-sEVs ameliorated hepatic injuries and fibrosis in chronically damaged liver induced by carbon tetrachloride (CCl₄). miR-486-5p highly enriched in T-MSC-sEVs targeting the hedgehog receptor, smoothened (Smo), was upregulated, whereas Smo and Gli2, the hedgehog target gene, were downregulated in pHSCs and liver tissues treated with T-MSC-sEVs or miR-486-5p mimic, indicating that sEV-miR-486 inactivates HSCs by suppressing hedgehog signaling. Our results showed that T-MSCs attenuate HSC activation and liver fibrosis by delivering sEVs, and miR-486 in the sEVs inactivates hedgehog signaling, suggesting that T-MSCs and their sEVs are novel anti-fibrotic therapeutics for treating chronic liver disease.

A novel stem cell therapy for hepatitis B virus-related acute-on-chronic liver failure

The aim of this study was to propose a stem cell therapy for hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF) based on plasma exchange (PE) for peripheral blood stem cell (PBSC) collection and examine its safety and efficacy. Sixty patients (n=20 in each group) were randomized to PE (PE alone), granulocyte colony-stimulating factor (G-CSF) (PE after G-CSF treatment), and PBSC transplantation (PBSCT) (G-CSF, PE, PBSC collection and hepatic artery injection) groups. Patients were followed-up for 24 weeks. Liver function and adverse events were recorded. Survival analysis was performed. PBSCT improved blood ammonia levels at 1 week (P<0.05). The level of total bilirubin, international normalized ratio, and creatinine showed significant differences in the 4th week of treatment (P<0.05). The survival rates of the PE, G-CSF, and PBSCT groups were 50, 65, and 85% at 90 days (P=0.034). There was a significant difference in 90-day survival between the PE and PBSCT groups (P=0.021). The preliminary results suggested that PBSCT was safe, with a possibility of improved 90-day survival in patients with HBV-ACLF.

G-CSF Inhibits Pulmonary Fibrosis by Promoting BMSC Homing to the Lungs via SDF-1/CXCR4 Chemotaxis

Bone marrow mesenchymal stem cells (BMSCs) have multi-lineage differentiation potential and play an important role in tissue repair. Studies have shown that BMSCs gather at the injured tissue site after granulocyte-colony stimulating factor (G-CSF) administration. In this study, we first investigated whether G-CSF could promote BMSC homing to damaged lung tissue induced by bleomycin (BLM) and then investigated whether SDF-1/CXCR4 chemotaxis might be involved in this process. Next, we further studied the potential inhibitory effect of G-CSF administration in mice with lung fibrosis induced by bleomycin. We examined both the antifibrotic effects of G-CSF in mice with bleomycin-induced pulmonary fibrosis in vivo and its effects on the proliferation, differentiation and chemotactic movement of cells in vitro. Flow cytometry, real-time PCR, transwell and Cell Counting Kit-8 (CCK-8) assays were used in this study. The results showed that both preventative and therapeutic G-CSF administration could significantly inhibit bleomycin-induced pulmonary fibrosis. G-CSF enhanced BMSC migration to lung tissues, but this effect could be alleviated by AMD3100, which blocked the SDF-1/CXCR4 axis. We also found that BMSCs could inhibit fibroblast proliferation and transdifferentiation into myofibroblasts through paracrine actions. In conclusion, G-CSF exerted antifibrotic effects in bleomycin-induced lung fibrosis, in part by promoting BMSC homing to injured lung tissues via SDF-1/CXCR4 chemotaxis.

Normothermic Machine Perfusion Combined with Bone Marrow Mesenchymal Stem Cells Improves the Oxidative Stress Response and Mitochondrial Function in Rat Donation After Circulatory Death Livers

There is a need to improve the quality of donor liver from donation after circulatory death (DCD). The purpose of this study was to investigate the effects and mechanism of normothermic machine perfusion (NMP) combined with bone marrow mesenchymal stem cells (BMMSCs) on the oxidative stress and mitochondrial function in DCD livers. DCD livers were obtained, a rat NMP system was established, and BMMSCs were extracted and identified. The DCD livers were grouped by their preservation method: Normal, static cold storage (SCS), NMP (P), and NMP combined with BMMSCs (PB), and the preservation time was up to 8 h. An IAR20 cell oxidative stress injury model was established in vitro by simulating DCD oxidative stress injury and coculturing with BMMSCs for 6 h. Compared with SCS group, after 6 h in vitro, the PB and P groups had significantly improved liver function and liver histological damage, reduced hepatocyte apoptosis and oxidative stress, improved hepatocyte mitochondrial damage, and increased mitochondrial membrane potential. These indicators were significantly better in the PB group than in the P group. BMMSCs significantly inhibited reactive oxygen species release from the IAR20 cell oxidative stress model in vitro, ameliorated mitochondrial damage, and increased mitochondrial membrane potential level. BMMSCs also downregulated the JUN N-terminal kinase-nuclear factor kappa B (JNK-NF-κB) signaling pathway significantly in the IAR20 cell oxidative stress model and promoted AMP-activated protein kinase (AMPK) activation. We verified that NMP combined with BMMSCs also played the same role in the PB group. NMP combined with BMMSCs could improve liver quality by relieving oxidative stress injury and improving mitochondrial function in rat DCD livers. The mechanism of protective role might involve inhibiting the JNK-NF-κB pathway to reduce oxidative stress and promote AMPK activation, thereby reducing mitochondrial damage and increase mitochondrial function.

Autologous bone marrow stem cell transplantation via the hepatic artery for the treatment of hepatitis B virus-related cirrhosis: a PRISMA-compliant meta-analysis based on the Chinese population

Objective

Autologous bone marrow stem cell (ABMSC) transplantation has been considered a promising option for hepatitis B virus-related cirrhosis (HBV-C). Although an analysis of the published literature has been performed, the exact effects and safety have yet to be systematically investigated.

Methods

We conducted a wide-ranging online search of electronic databases (Web of Science, PubMed, Cochrane Library, Embase, CNKI, VIP, and Wanfang database) to reach systematic conclusions. Outcome measurements, including therapeutic efficacy, clinical symptoms, and adverse events, were extracted and analyzed statistically.

Results

Ultimately, a total of 10 articles including 662 HBV-C patients were included in this analysis, which indicated that ABMSC therapy could significantly improve liver function in patients with HBV-C in terms of the MELD and Child-Pugh scores, total bilirubin, serum albumin, alanine aminotransferase, aspartate aminotransferase, and coagulation function. Compared with patients receiving routine therapy (RT), those treated with ABMSC and RT combined therapy showed improved clinical symptoms, as represented by increased appetite and reduced fatigue and ascitic fluid and abdominal distension. Moreover, the fibrosis indexes indicated a reduction in liver fibrosis in patients treated with combined therapy according to the improved levels of hyaluronic acid (MD = − 70.47, CI = − 103.72–37.21, P <  0.0001), laminin (MD = − 25.11, CI = − 37.73–12.49, P <  0.0001), type III procollagen (MD = − 22.42, CI = − 34.49–10.34, P = 0.0003), and type IV collagen (MD = − 22.50, CI = − 39.92–5.08, P = 0.01). No obvious adverse events occurred during ABMSC treatment.

Conclusion

ABMSC transplantation via the hepatic artery was safe and effective in treating HBV-C without causing severe adverse events.

The Effect of Mesenchymal Stem Cells Derived Microvesicles on the Treatment of Experimental CCL4 Induced Liver Fibrosis in Rats

Background and Objectives

The release of microvesicles (MVs) from mesenchymal stem cells (MSCs) has been implicated in intercellular communication, and may contribute to beneficial paracrine effects of stem cell-based therapies. We investigated the effect of administration of MSC-MVs on the therapeutic potential of carbon tetrachloride (CCL₄) induced liver fibrosis in rats.

Methods

Our work included: isolation and further identification of bone marrow MSC-MVs by transmission electron microscopy (TEM). Liver fibrosis was induced in rats by CCl4 followed by injection of prepared MSC-MVs in injured rats. The effects of MSC-MVs were evaluated by biochemical analysis of liver functions, RNA gene expression quantitation for collagen-1α, transforming growth factor β (TGF-β), interleukin-1β (IL-1β), vascular endothelial growth factor (VEGF) by real time reverse transcription PCR (RT-PCR) techniques. Finally histopathological examination of the liver tissues was assessed for all studied groups.

Results

BM-MSC-MVs treated group showed significant increase in serum albumin levels, VEGF quantitative gene expression (p<0.05), while it showed a significant decrease in serum alanine transaminase (ALT) enzyme levels, quantitative gene expression of TGF-β, collagen-1α, IL-1β compared to CCL₄ fibrotic group (p<0.05). Additionally, the histopathological assessment of the liver tissues of BM-MSC-MVs treated group showed marked decrease in the collagen deposition & improvement of histopathological picture in comparison with CCL₄ fibrotic group.

Conclusions

Our study demonstrates that BM-MSC-MVs possess anti-fibrotic, anti-inflammatory, and pro-angiogenic properties which can promote the resolution of CCL₄ induced liver fibrosis in rats.

Stem Cell-Related Studies and Stem Cell-Based Therapies in Liver Diseases

Owing to the increasing worldwide burden of liver diseases, the crucial need for safe and effective interventions for treating end-stage liver failure has been a very productive line of inquiry in the discipline of hepatology for many years. Liver transplantation is recognized as the most effective treatment for end-stage liver disease; however, the shortage of donor organs, high medical costs, and lifelong use of immunosuppressive agents represent major drawbacks and demand exploration for alternative treatments. Stem cell-based therapies have been widely studied in the field of liver diseases and are considered to be among the most promising therapies. Herein, we review recent advances in the application of stem cell-related therapies in liver disease with the aim of providing readers with relevant knowledge in this field and inspiration to spur further inquiry.

Response-Related Factors of Bone Marrow-Derived Mesenchymal Stem Cells Transplantation in Patients with Alcoholic Cirrhosis

Liver cirrhosis leads to hepatic dysfunction and life-threatening conditions. Although the clinical efficacy of autologous bone marrow-derived mesenchymal stem cells (BM-MSC) transplantation in alcoholic cirrhosis (AC) was demonstrated, the relevant mechanism has not been elucidated. We aimed to identify the predictive factors and gene/pathways for responders after autologous BM-MSC transplantation. Fifty-five patients with biopsy-proven AC underwent autologous BM-MSC transplantation. The characteristics of responders who showed improvement in fibrosis score (≥1) after transplantation were compared with those of non-responders. BM-MSCs were analyzed with cDNA microarrays to identify gene/pathways that were differentially expressed in responders. Thirty-three patients (66%) were responders. A high initial Laennec score (p = 0.007, odds ratio 3.73) and performance of BM-MSC transplantation (p = 0.033, odds ratio 5.75) were predictive factors for responders. Three genes (olfactory receptor2L8, microRNA4520-2, and chloride intracellular channel protein3) were upregulated in responders, and CD36 and retinol-binding protein 4 are associated with the biologic processes that are dominant in non-responders. Eleven pathways (inositol phosphate, ATP-binding cassette transporters, protein-kinase signaling, extracellular matrix receptor interaction, endocytosis, phagosome, hematopoietic cell lineage, adipocytokine, peroxisome proliferator-activated receptor, fat digestion/absorption, and insulin resistance) were upregulated in non-responders (p < 0.05). BM-MSC transplantation may be warranted treatment for AC patients with high Laennec scores. Cell-based therapy utilizing response-related genes or pathways can be a treatment candidate.

Transplantation of bone marrow mesenchymal stromal cells attenuates liver fibrosis in mice by regulating macrophage subtypes

Background

Liver fibrosis is a key phase that will progress to further injuries such as liver cirrhosis or carcinoma. This study aimed to investigate whether transplantation of bone marrow mesenchymal stromal cells (BM-MSCs) can attenuate liver fibrosis in mice and the underlying mechanisms based on the regulation of macrophage subtypes.

Methods

A liver fibrosis model was induced by intraperitoneal (i.p.) injection of CCl4 twice per week for 70 days, and BM-MSCs were intravenously transplanted twice on the 60th and 70th days. Immunohistology and gene expression of liver fibrosis and macrophage subtypes were analyzed. Mouse RAW264.7 cells and JS1 cells (hepatic stellate cell strain) were also used to explore the underlying mechanisms of the effects of BM-MSCs on liver fibrosis.

Results

After transplantation of BM-MSCs, F4/80⁺CD206⁺-activated M2 macrophages and matrix metalloproteinase 13 (MMP 13) expression were significantly increased while F4/80⁺iNOS⁺-activated M1 macrophages were inhibited in liver tissue. Gene expression of IL-10 was elevated while IL12b, IFN-γ, TNF-α, and IL-6 gene expression were decreased. ΤGF-β1 and collagen-1 secretions were reduced while caspase-3 was increased in JS1 cells treated with BM-MSC-conditioned media. BM-MSCs effectively suppressed the expression of α-SMA, Sirius red, and collagen-1 in the liver, which are positively correlated with fibrosis and induced by CCl4 injection.

Conclusions

Taken together, we have provided the first demonstration that BM-MSC transplantation can promote the activation of M2 macrophages expressing MMP13 and inhibition of M1 macrophages to further inhibit hepatic stellate cells (HSCs), which play synergistic roles in attenuating liver fibrosis.

Pretreatment with G-CSF Could Enhance the Antifibrotic Effect of BM-MSCs on Pulmonary Fibrosis

Granulocyte colony-stimulating factor (G-CSF) can promote the repair of a variety of damaged tissues, but the underlying mechanisms have not yet been fully elucidated. Bone marrow mesenchymal stem cells (BM-MSCs) play an important role in the repair of damaged tissue. The aim of this study was to explore whether pretreating BM-MSCs with G-CSF can promote their ability of homing to the lung after in vitro transplantation via upregulating the CXCR4 expression, potentially markedly increasing the antifibrotic effect of BM-MSCs. The BM-MSCs pretreated with G-CSF were transplanted into a mouse on day 14 after bleomycin injection. The antifibrotic effects of BM-MSCs in mice were tested on day 21 by using pathological examination and collagen content assay. Pretreatment of BM-MSCs with G-CSF significantly promoted their ability of homing to the lung and enhanced their antifibrotic effects. However, knocking down the CXCR4 expression in BM-MSCs significantly inhibited the ability of G-CSF to promote the migration and homing of BM-MSCs to the lung and the resulting antifibrotic effects. We also found that G-CSF significantly increased the CXCR4 expression and AKT phosphorylation in BM-MSCs, and the AKT pathway inhibitor LY294002 significantly diminished the ability of G-CSF to upregulate the CXCR4 expression in BM-MSCs. Pretreatment of BM-MSCs with G-CSF promotes the homing of BM-MSCs to the lung via upregulating the CXCR4 expression, leading to a marked increase in the antifibrotic effects of BM-MSCs. This study provides new avenues for the application of BM-MSCs in the repair of different tissues.

Thioacetamide-induced hepatic fibrosis in the common marmoset

The common marmoset (Callithrix jacchus) is a nonhuman primate that is used for preclinical research on stem cell transplantation therapies due to its similarity to human beings as well as its small size, enabling researchers to perform experiments without preparing a large number of cells. In this study, we developed a marmoset hepatic fibrosis model for regenerative medicine research. Six female marmosets aged 4–6 years were administered thioacetamide (TAA) at a dose of 2.5–40 mg/kg two or three times a week. Hepatic fibrosis was assessed by liver biopsy when blood chemistry indicated liver damage. Administration of TAA increased total bile acid, aspartate aminotransferase, and total bilirubin and decreased serum albumin levels. Following more than 11 weeks of continuous injection of TAA, histological analyses detected hepatic fibrosis in all animals. Type IV collagen 7S serum levels in animals with hepatic fibrosis were significantly higher than in normal animals as a possible marker of hepatic fibrosis in marmosets. Serial liver biopsies following the last administration of TAA revealed that induced fibrosis remained up to 11 weeks. The results suggest that continuous TAA administration induces persistent hepatic fibrosis in the common marmoset and this nonhuman primate hepatic fibrosis model have the possibility to evaluate the therapeutic effects of test samples to ameliorate hepatic fibrosis.

A pooled analysis of mesenchymal stem cell-based therapy for liver disease

Background

Liver disease is a major cause of death and disability. Mesenchymal stem cells (MSCs) show promise for the treatment of liver disease. However, whether MSC-based therapy is more effective than conventional treatment is unclear, as are the optimal MSC source, the administration frequency, and the most effective MSC delivery route. We therefore undertook a systematic review and meta-analysis of the therapeutic efficacy of MSCs against liver disease and the related factors.

Methods

We systematically searched Medline (PubMed), Cochrane Library, EMBASE, ClinicalTrials.gov, and SinoMed CBM to identify studies published up to June 2017 involving liver disease patients receiving MSC-based therapy and which reported estimates of liver function during the follow-up period.

Results

Thirty-nine studies were selected from 672 publications. According to a meta-analysis of 23 controlled studies, compared with conventional treatment MSC therapy significantly improves liver function in patients with liver disease in terms of the model of end-stage liver disease score, albumin, alanine aminotransferase, and total bilirubin levels, and prothrombin time, up to 6 months after administration. However, it has no beneficial effects in terms of prothrombin activity, international normalized ratio, or cholinesterase level. Considerable heterogeneity was identified at most time points. Subgroup analyses showed that a single MSC injection was more effective than multiple injections, MSC administration was more effective via the hepatic artery than the peripheral vein, and MSCs derived from bone marrow were more effective than those derived from the umbilical cord.

Conclusions

MSC-based therapy is relatively safe and improves liver function during the first 6 months after administration. A single injection administration via the hepatic artery and MSCs derived from bone marrow are optimal in terms of improving liver function. However the significant heterogeneity among studies and discontinuous results of the subgroup meta-analysis should be addressed; moreover the long-term efficacy of MSC therapy warrants further investigation.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-0816-2) contains supplementary material, which is available to authorized users.

Current Perspectives Regarding Stem Cell-Based Therapy for Liver Cirrhosis

Liver cirrhosis is a major cause of mortality and a common end of various progressive liver diseases. Since the effective treatment is currently limited to liver transplantation, stem cell-based therapy as an alternative has attracted interest due to promising results from preclinical and clinical studies. However, there is still much to be understood regarding the precise mechanisms of action. A number of stem cells from different origins have been employed for hepatic regeneration with different degrees of success. The present review presents a synopsis of stem cell research for the treatment of patients with liver cirrhosis according to the stem cell type. Clinical trials to date are summarized briefly. Finally, issues to be resolved and future perspectives are discussed with regard to clinical applications.

Increased motility of mesenchymal stem cells is correlated with inhibition of stimulated peripheral blood mononuclear cells in vitro

Immunomodulatory properties of mesenchymal stem cells (MSC) are key components of their successful applications in clinical setting. However, treatments based on MSC immunomodulation need understanding of cell characteristics before cell transplantation. We used live-imaging to test the suitability of the MSC motility as a parameter for quick prediction of the immunomodulatory potential of human MSC in regulating the activity of stimulated peripheral blood mononuclear cells (PBMC) in vitro. Bone marrow MSC, from various donors and in vitro passages, were cultured with or without stimulated PBMC. After seven days, immunomodulation was assessed by measuring PBMC proliferation, IgG production and cytokine secretion in MSC and PBMC monocultures and co-cultures, and results were correlated to MSC motility. In co-culture, we observed that MSC successfully inhibited PBMC activity, reducing PBMC proliferation and IgG production compared to PBMC monoculture. MSC modulated PBMC to reduce the secretion of TNFα and IL-10, increase IL-6, G-CSF and MCP-1, while GM-CSF was not affected. By live-imaging tracking of cell trajectories, we observed that fast moving MSC were inhibiting more efficiently stimulated PBMC compared to slow ones. In co-culture, fast MSC were more effective in inhibiting IgG production (˜30% less IgG), and secreted higher levels of IL-10 (˜10% increase) and GM-CSF (˜20% increase) compared to slower cells. Furthermore, fast MSC in monocultures produced 2.3-fold more IL-6, 1.5-fold MCP-1 and 1.2-fold G-CSF in comparison to slower cells. In conclusion, live-imaging cell tracking allowed us to develop an indicative assay of the immune-regulatory potential of MSC prior to in vivo administration. Key Words: Human mesenchymal stem cells, Immunomodulatory potential, In vitro cell motility, Stem cell transplantation.

Current Understanding of Stem Cell and Secretome Therapies in Liver Diseases

Liver failure is one of the main risks of death worldwide, and it originates from repetitive injuries and inflammations of liver tissues, which finally leads to the liver cirrhosis or cancer. Currently, liver transplantation is the only effective treatment for the liver diseases although it has a limitation due to donor scarcity. Alternatively, cell therapy to regenerate and reconstruct the damaged liver has been suggested to overcome the current limitation of liver disease cures. Several transplantable cell types could be utilized for recovering liver functions in injured liver, including bone marrow cells, mesenchymal stem cells, hematopoietic stem cells, macrophages, and stem cell-derived hepatocytes. Furthermore, paracrine effects of transplanted cells have been suggested as a new paradigm for liver disease cures, and this application would be a new strategy to cure liver failures. Therefore, here we reviewed the current status and challenges of therapy using stem cells for liver disease treatments.

Transplantation of human bone marrow mesenchymal stromal cells reduces liver fibrosis more effectively than Wharton's jelly mesenchymal stromal cells

Background

Mesenchymal stromal cells (MSCs) from various tissues have shown moderate therapeutic efficacy in reversing liver fibrosis in preclinical models. Here, we compared the relative therapeutic potential of pooled, adult human bone marrow (BM)- and neonatal Wharton’s jelly (WJ)-derived MSCs to treat CCl₄-induced liver fibrosis in rats.

Methods

Sprague-Dawley rats were injected with CCl₄ for 8 weeks to induce irreversible liver fibrosis. Ex-vivo expanded, pooled human MSCs obtained from BM and WJ were intravenously administered into rats with liver fibrosis at a dose of 10 × 10⁶ cells/animal. Sham control and vehicle-treated animals served as negative and disease controls, respectively. The animals were sacrificed at 30 and 70 days after cell transplantation and hepatic-hydroxyproline content, histopathological, and immunohistochemical analyses were performed.

Results

BM-MSCs treatment showed a marked reduction in liver fibrosis as determined by Masson’s trichrome and Sirius red staining as compared to those treated with the vehicle. Furthermore, hepatic-hydroxyproline content and percentage collagen proportionate area were found to be significantly lower in the BM-MSCs-treated group. In contrast, WJ-MSCs treatment showed less reduction of fibrosis at both time points. Immunohistochemical analysis of BM-MSCs-treated liver samples showed a reduction in α-SMA⁺ myofibroblasts and increased number of EpCAM⁺ hepatic progenitor cells, along with Ki-67⁺ and human matrix metalloprotease-1⁺ (MMP-1⁺) cells as compared to WJ-MSCs-treated rat livers.

Conclusions

Our findings suggest that BM-MSCs are more effective than WJ-MSCs in treating liver fibrosis in a CCl₄-induced model in rats. The superior therapeutic activity of BM-MSCs may be attributed to their expression of certain MMPs and angiogenic factors.

Current status and future prospects of mesenchymal stem cell therapy for liver fibrosis

Liver fibrosis is the end-stage of many chronic liver diseases and is a significant health threat. The only effective therapy is liver transplantation, which still has many problems, including the lack of donor sources, immunological rejection, and high surgery costs, among others. However, the use of cell therapy is becoming more prevalent, and mesenchymal stem cells (MSCs) seem to be a promising cell type for the treatment of liver fibrosis. MSCs have multiple differentiation abilities, allowing them to migrate directly into injured tissue and differentiate into hepatocyte-like cells. Additionally, MSCs can release various growth factors and cytokines to increase hepatocyte regeneration, regress liver fibrosis, and regulate inflammation and immune responses. In this review, we summarize the current uses of MSC therapies for liver fibrosis and suggest potential future applications.

Effects of heme oxygenase-1-modified bone marrow mesenchymal stem cells on microcirculation and energy metabolism following liver transplantation

AIM

To investigate the effects of heme oxygenase-1 (HO-1)-modified bone marrow mesenchymal stem cells (BMMSCs) on the microcirculation and energy metabolism of hepatic sinusoids following reduced-size liver transplantation (RLT) in a rat model.

METHODS

BMMSCs were isolated and cultured in vitro using an adherent method, and then transduced with HO-1-bearing recombinant adenovirus to construct HO-1/BMMSCs. A rat acute rejection model following 50% RLT was established using a two-cuff technique. Recipients were divided into three groups based on the treatment received: normal saline (NS), BMMSCs and HO-1/BMMSCs. Liver function was examined at six time points. The levels of endothelin-1 (ET-1), endothelial nitric-oxide synthase (eNOS), inducible nitric-oxide synthase (iNOS), nitric oxide (NO), and hyaluronic acid (HA) were detected using an enzyme-linked immunosorbent assay. The portal vein pressure (PVP) was detected by Power Lab ML880. The expressions of ET-1, iNOS, eNOS, and von Willebrand factor (vWF) protein in the transplanted liver were detected using immunohistochemistry and Western blotting. ATPase in the transplanted liver was detected by chemical colorimetry, and the ultrastructural changes were observed under a transmission electron microscope.

RESULTS

HO-1/BMMSCs could alleviate the pathological changes and rejection activity index of the transplanted liver, and improve the liver function of rats following 50% RLT, with statistically significant differences compared with those of the NS group and BMMSCs group (P < 0.05). In term of the microcirculation of hepatic sinusoids: The PVP on POD7 decreased significantly in the HO-1/BMMSCs and BMMSCs groups compared with that of the NS group (P < 0.01); HO-1/BMMSCs could inhibit the expressions of ET-1 and iNOS, increase the expressions of eNOS and inhibit amounts of NO production, and maintain the equilibrium of ET-1/NO (P < 0.05); and HO-1/BMMSCs increased the expression of vWF in hepatic sinusoidal endothelial cells (SECs), and promoted the degradation of HA, compared with those of the NS group and BMMSCs group (P < 0.05). In term of the energy metabolism of the transplanted liver, HO-1/BMMSCs repaired the damaged mitochondria, and improved the activity of mitochondrial aspartate aminotransferase (ASTm) and ATPase, compared with the other two groups (P <0.05).

CONCLUSION

HO-1/BMMSCs can improve the microcirculation of hepatic sinusoids significantly, and recover the energy metabolism of damaged hepatocytes in rats following RLT, thus protecting the transplanted liver.

Transient elastography versus hepatic venous pressure gradient for diagnosing portal hypertension: a systematic review and meta-analysis

Background/Aims

Transient elastography (TE) has been proposed as a promising noninvasive alternative to hepatic venous pressure gradient (HVPG) for detecting portal hypertension (PH). However, previous studies have yielded conflicting results. We gathered evidence from literature on the clinical usefulness of TE versus HVPG for assessing PH.

Methods

We conducted a systematic review by searching databases for relevant literature evaluating the clinical usefulness of non-invasive TE for assessing PH in patients with cirrhosis. A literature search in Ovid Medline, EMBASE and the Cochrane Library was performed for all studies published prior to December 30, 2015.

Results

Eight studies (1,356 patients) met our inclusion criteria. For the detection of PH (HVPG ≥6 mmHg), the summary sensitivity and specificity were 0.88 (95% confidence interval [CI] 0.86-0.90) and 0.74 (95% CI 0.67-0.81), respectively. Regarding clinically significant PH (HVPG ≥10 mmHg), the summary sensitivity and specificity were 0.85 (95% CI 0.63-0.97) and 0.71 (95% CI 0.50-0.93), respectively. The overall correlation estimate of TE and HVPG was large (0.75, 95% CI: 0.65; 0.82, P<0.0001).

Conclusions

TE showed high accuracy and correlation for detecting the severity of PH. Therefore, TE shows promise as a reliable and non-invasive procedure for the evaluation of PH that should be integrated into clinical practice.

Progress in stem cell-based therapy for liver disease

Liver transplantation has been accepted as a useful therapeutic approach for patients with end-stage liver disease. However, the mismatch between the great demand for liver transplants and the number of available donor organs underscores the urgent need for alternative therapeutic strategies for patients with acute and chronic liver failure. The rapidly growing knowledge on stem cell biology has opened new avenues toward stem cell-based therapy for liver disease. As stem cells have capacity for high proliferation and multipotent differentiation, the characteristics of stem cells fit the cell therapy. Several types of cells have been investigated as possible sources of liver regeneration: mesenchymal stem cells, hematopoietic stem cells, liver progenitor cells, induced pluripotent stem cells, and bone marrow mononuclear cells. In vitro and in vivo experiments revealed that these cells have great potential as candidates of stem cell therapy. We reviewed the reports on clinical trials of cell therapy for liver disease that have been recently undertaken using mesenchymal stem cells, hematopoietic stem cells, bone marrow mononuclear cells, and liver progenitor cells. These reports have heterogeneity of description of trial design, types of infused cells, patient population, and efficacy of therapies. We addressed these reports from these viewpoints and clarified their significance. We hope that this review article will provide a perspective on the available approaches based on stem cell-based therapy for liver disease.

Transplantation with autologous bone marrow-derived mesenchymal stem cells for alcoholic cirrhosis: Phase 2 trial

Bone marrow-derived mesenchymal stem cell (BM-MSC) transplantation has been suggested as an effective therapy for liver cirrhosis. The efficacy and safety of autologous BM-MSC transplantation in the treatment of alcoholic cirrhosis were investigated. Seventy-two patients with baseline biopsy-proven alcoholic cirrhosis who had been alcohol-abstinent for more than 6 months underwent a multicenter, randomized, open-label, phase 2 trial. Patients were randomly assigned to three groups: one control group and two autologous BM-MSC groups that underwent either one-time or two-time hepatic arterial injections of 5 × 10⁷ BM-MSCs 30 days after BM aspiration. A follow-up biopsy was performed 6 months after enrollment, and adverse events were monitored for 12 months. The primary endpoint was improvement in fibrosis quantification based on picrosirius red staining. The secondary endpoints included liver function tests, Child-Pugh score, and Model for End-stage Liver Disease score. Outcomes were analyzed by per-protocol analysis. In terms of fibrosis quantification (before versus after), the one-time and two-time BM-MSC groups were associated with 25% (19.5 ± 9.5% versus 14.5 ± 7.1%) and 37% (21.1 ± 8.9% versus 13.2 ± 6.7%) reductions in the proportion of collagen, respectively (P < 0.001). In the intergroup comparison, two-time BM-MSC transplantation in comparison with one-time BM-MSC transplantation was not associated with improved results in fibrosis quantification (P > 0.05). The Child-Pugh scores of both BM-MSC groups (one-time 7.6 ± 1.0 versus 6.3 ± 1.3 and two-time 7.8 ± 1.2 versus 6.8 ± 1.6) were also significantly improved following BM-MSC transplantation (P < 0.05). The proportion of patients with adverse events did not differ among the three groups.

CONCLUSION

Autologous BM-MSC transplantation safely improved histologic fibrosis and liver function in patients with alcoholic cirrhosis. (Hepatology 2016;64:2185-2197).

Involvement of hepatic macrophages in the antifibrotic effect of IGF-I-overexpressing mesenchymal stromal cells

BACKGROUND

Cirrhosis is a major health problem worldwide and new therapies are needed. Hepatic macrophages (hMø) have a pivotal role in liver fibrosis, being able to act in both its promotion and its resolution. It is well-known that mesenchymal stromal cells (MSCs) can modulate the immune/inflammatory cells. However, the effects of MSCs over hMø in the context of liver fibrosis remain unclear. We previously described evidence of the antifibrotic effects of in vivo applying MSCs, which were enhanced by forced overexpression of insulin-like growth factor 1 (AdIGF-I-MSCs). The aim of this work was to analyze the effect of MSCs on hMø behavior in the context of liver fibrosis resolution.

METHODS

Fibrosis was induced in BALB/c mice by chronic administration of thioacetamide (8 weeks). In vivo gene expression analyses, in vitro experiments using hMø isolated from the nonparenchymal liver cells fraction, and in vivo experiments with depletion of Mø were performed.

RESULTS

One day after treatment, hMø from fibrotic livers of MSCs-treated animals showed reduced pro-inflammatory and pro-fibrogenic gene expression profiles. These shifts were more pronounced in AdIGF-I-MSCs condition. This group showed a significant upregulation in the expression of arginase-1 and a higher downregulation of iNOS expression thus suggesting decreased levels of oxidative stress. An upregulation in IGF-I and HGF expression was observed in hMø from AdIGF-I-MSCs-treated mice suggesting a restorative phenotype in these cells. Factors secreted by hMø, preconditioned with MSCs supernatant, caused a reduction in the expression levels of hepatic stellate cells pro-fibrogenic and activation markers. Interestingly, hMø depletion abrogated the therapeutic effect achieved with AdIGF-I-MSCs therapy. Expression profile analyses for cell cycle markers were performed on fibrotic livers after treatment with AdIGF-I-MSCs and showed a significant regulation in genes related to DNA synthesis and repair quality control, cell cycle progression, and DNA damage/cellular stress compatible with early induction of pro-regenerative and hepatoprotective mechanisms. Moreover, depletion of hMø abrogated such effects on the expression of the most highly regulated genes.

CONCLUSIONS

Our results indicate that AdIGF-I-MSCs are able to induce a pro-fibrotic to resolutive phenotype shift on hepatic macrophages, which is a key early event driving liver fibrosis amelioration.

Cell therapy in chronic liver disease

PURPOSE OF REVIEW

To date, the only curative treatment for end-stage liver disease is liver transplantation, which is limited by the shortage of available organs. Cell therapy, in the form of cell transplantation or cell-based extracorporeal support devices, may in the future offer an alternative to transplantation, or at least provide liver function support as a bridging therapy until surgery may be performed. The purpose of this review is to highlight the most recent advances made in the field of cell therapy and regenerative medicine for the treatment of chronic liver disease.

RECENT FINDINGS

After hepatocyte transplantation, long-term engraftment in the liver and spleen may be achieved, which can be stimulated through preconditioning, multiple infusions, and inflammatory response blockade. Mesenchymal stem cells are promising candidates for cell transplantation, as they have been shown to reduce liver fibrosis and support endogenous regeneration. Adipose tissue-derived stem cells are also being tested in this setting, because of their ready availability. Bioartificial liver devices are being built that allow for effective preservation of hepatocytes, and one such device has recently demonstrated survival benefit in a porcine model of liver failure.

SUMMARY

Cell transplantation of primary hepatocytes or stem cell-derived hepatocyte-like cells for the treatment of chronic liver disease holds promise. Bioartificial liver systems may in the future be able to bridge acute-on-chronic liver failure patients to liver transplantation.

HGF gene modified bone marrow mesenchymal stem cells for treatment of hepatic fibrosis

Hepatic fibrosis is a reversible pathological change caused by liver cell inflammation, necrosis, or abnormal hyperplasia of connective tissue. It has been proved that hepatocyte growth factor (HGF) gene modified bone marrow mesenchymal stem cells can reduce or inhibit liver fibrosis, with better effects than those of unmodified bone marrow mesenchymal stem cells. Thus, HGF gene modified bone marrow mesenchymal stem cells represent a promising method for anti-hepatic fibrosis.