Reinfusion of highly purified CD133+ bone marrow-derived stem/progenitor cells in patients with end-stage liver disease: A phase I clinical trial

Stem cell therapy for hepatocellular carcinoma and end-stage liver disease

Hepatocellular carcinoma (HCC) is a major health problem worldwide, especially for patients who are suffering from end-stage liver disease (ESLD). The ESLD is considered a great challenge for clinicians due to the limited chance for liver transplantation, which is the only curative treatment for those patients. Stem cell-based therapy as a part of regenerative medicine represents a promising application for ESLD patients. Many clinical trials were performed to assess the utility of bone marrow-derived stem cells as a potential therapy for patients with liver diseases. The aim of the present study is to present and review the various types of stem cell-based therapy, including the mesenchymal stem cells (MSCs), BM-derived mononuclear cells (BM-MNCs), CD34 + hematopoietic stem cells (HSCs), induced pluripotent stem cells (iPSCs), and cancer stem cells.Though this type of therapy achieved promising results for the treatment of ESLD, however still there is a confounding data regarding its clinical application. A large body of evidence is highly required to evaluate the stem cell-based therapy after long-term follow-up, with respect to the incidence of toxicity, immunogenicity, and tumorigenesis that developed in many patients.

Liver regeneration as treatment target for severe alcoholic hepatitis

Severe alcoholic hepatitis (AH) is a distinct entity in the spectrum of alcohol-related liver disease, with limited treatment options and high mortality. Supportive medical care with corticosteroids in selected patients is the only currently available treatment option, often with poor outcomes. Based on the insights into the pathogenetic mechanisms of AH, which are mostly obtained from animal studies, several new treatment options are being explored. Studies have implicated impaired and deranged liver regeneration processes as one of the culprit mechanisms and a potential therapeutic target. Acknowledging evidence for the beneficial effects of granulocyte colony-stimulating factor (G-CSF) on liver regeneration and immunomodulation in animal models, several human studies investigated its role in the treatment of advanced alcohol-related liver disease and AH. Contrary to the previously published studies suggesting benefits of G-CSF in the outcomes of patients with severe AH, these effects were not confirmed by a recently published multicenter randomized trial, suggesting that other options should rather be pursued. Stem cell transplantation represents another option for improving liver regeneration, but evidence for its efficacy in patients with severe AH and advanced alcohol-related liver disease is still very scarce and unconvincing, with established lack of efficacy in patients with compensated cirrhosis. In this review, we summarize the current knowledge on the pathogenesis and experimental therapies targeting liver regeneration. The lack of high-quality studies and evidence is a major obstacle in further treatment development. New insights into the pathogenesis of not only liver injury, but also liver regeneration processes are mandatory for the development of new treatment options. A reliable experimental model of the pathogenesis of AH and processes involved in liver recovery is still missing, and data obtained from animal studies are essential for future research.

Mesenchymal Stem Cell Transplantation in Liver Diseases

Promising preclinical data suggested that bone marrow-derived mesenchymal stem cells (BM-MSC) can reduce hepatic fibrosis and stimulate liver regeneration. Preclinical studies moreover suggested that the immunomodulatory and anti-inflammatory functions of MSCs may reduce hepatic inflammation, improve liver function, and decrease infection incidences which are deemed especially important in the case of acute-on-chronic liver failure (ACLF). Studies in patients with decompensated cirrhosis demonstrated that injection of BM-MSC resulted in an improvement of biochemical tests and led to a survival benefit in ACLF. Most of these studies were performed in hepatitis B virus infected patients. However, two adequately powered studies performed in Europe could not confirm these data. A possible alternative to mobilize BM-MSC into the liver is the use of granulocyte colony-stimulating factor (G-CSF) which has proregenerative and immunomodulatory effects. In Indian studies, the use of G-CSF was associated with improvement of survival, although this finding could not be confirmed in European studies. Human allogeneic liver-derived progenitor cell therapy represents a potential treatment for ACLF, of which the main action is paracrine. These human liver-derived MSC can perform various functions, including the downregulation of proinflammatory responses. The clinical beneficial effect of these cells is further explored in patients with alcoholic cirrhosis and ACLF in Europe.

Liver Regeneration by Hematopoietic Stem Cells: Have We Reached the End of the Road?

The liver is the organ with the highest regenerative capacity in the human body. However, various insults, including viral infections, alcohol or drug abuse, and metabolic overload, may cause chronic inflammation and fibrosis, leading to irreversible liver dysfunction. Despite advances in surgery and pharmacological treatments, liver diseases remain a leading cause of death worldwide. To address the shortage of donor liver organs for orthotopic liver transplantation, cell therapy in liver disease has emerged as a promising regenerative treatment. Sources include primary hepatocytes or functional hepatocytes generated from the reprogramming of induced pluripotent stem cells (iPSC). Different types of stem cells have also been employed for transplantation to trigger regeneration, including hematopoietic stem cells (HSCs), mesenchymal stromal cells (MSCs), endothelial progenitor cells (EPCs) as well as adult and fetal liver progenitor cells. HSCs, usually defined by the expression of CD34 and CD133, and MSCs, defined by the expression of CD105, CD73, and CD90, are attractive sources due to their autologous nature, ease of isolation and cryopreservation. The present review focuses on the use of bone marrow HSCs for liver regeneration, presenting evidence for an ongoing crosstalk between the hematopoietic and the hepatic system. This relationship commences during embryogenesis when the fetal liver emerges as the crossroads between the two systems converging the presence of different origins of cells (mesoderm and endoderm) in the same organ. Ample evidence indicates that the fetal liver supports the maturation and expansion of HSCs during development but also later on in life. Moreover, the fact that the adult liver remains one of the few sites for extramedullary hematopoiesis—albeit pathological—suggests that this relationship between the two systems is ongoing. Can, however, the hematopoietic system offer similar support to the liver? The majority of clinical studies using hematopoietic cell transplantation in patients with liver disease report favourable observations. The underlying mechanism—whether paracrine, fusion or transdifferentiation or a combination of the three—remains to be confirmed.

Stem Cell-based Therapy Strategy for Hepatic Fibrosis by Targeting Intrahepatic Cells

The whole liver transplantation is the most effective treatment for end-stage fibrosis. However, the lack of available donors, immune rejection and total cost of surgery remain as the key challenges in advancing liver fibrosis therapeutics. Due to the multi-differentiation and low immunogenicity of stem cells, treatment of liver fibrosis with stem cells has been considered as a valuable new therapeutic modality. The pathological progression of liver fibrosis is closely related to the changes in the activities of intrahepatic cells. Damaged hepatocytes, activated Kupffer cells and other inflammatory cells lead to hepatic stellate cells (HSCs) activation, further promoting apoptosis of damaged hepatocytes, while stem cells can work on fibrosis-related intrahepatic cells through relevant transduction pathways. Herein, this article elucidates the phenomena and the mechanisms of the crosstalk between various types of stem cells and intrahepatic cells including HSCs and hepatocytes in the treatment of liver fibrosis. Then, the important influences of chemical compositions, mechanical properties and blood flow on liver fibrosis models with stem cell treatment are emphasized. Clinical trials on stem cell-based therapy for liver fibrosis are also briefly summarized. Finally, continuing challenges and future directions of stem cell-based therapy for hepatic fibrosis are discussed. In short, stem cells play an important advantage and have a great potential in treating liver fibrosis by interacting with intrahepatic cells. Clarifying how stem cells interact with intrahepatic cells to change the progression of liver fibrosis is of great significance for a deeper understanding of liver fibrosis mechanisms and targeted therapy.

CD133, a Progenitor Cell Marker, is Reduced in Nasal Polyposis and Showed Significant Correlations with TGF-β1 and IL-8

Introduction  Combination of chronic inflammation and an altered tissue remodeling process are involved in the development of Chronic Rhinosinusitis with Nasal Polyps (CRSwNP). Studies demonstrated that mesenchymal stem cells expressing the progenitor gene CD133 were involved in a significant reduction of the chronic inflammatory process in the polypoid tissue.

Objective  To evaluate the levels of CD133 (Prominin-1) in nasal polypoid tissue and its correlation with interleukin-8 (IL-8) and transforming growth factor β1 (TGF-β1).

Methods  A total of 74 subjects were divided in the following groups: control group ( n  = 35); chronic rhinosinusitis with nasal polyps nonpresenting comorbid asthma and aspirin intolerance (CRSwNPnonAI) group ( n  = 27); and chronic rhinosinusitis with nasal polyps presenting comorbid asthma and aspirin intolerance (CRSwNPAI) group ( n  = 12). Histologic analysis and also evaluation of the concentration of CD133, IL-8, and TGF-β1 by enzyme-linked immunosorbent assay (ELISA) kits were performed in nasal tissue obtained from nasal polypectomy or from middle turbinate tissue.

Results  Higher eosinophilic infiltration was found in both CRSwNP groups by histologic analysis. Lower levels of TGF-β1 and IL-8 were observed in both CRSwNP groups when compared with the control group, whereas the CD133 levels were significantly reduced only in the CRSwNPnonAI group compared with the control group.

Conclusion  It was demonstrated that the nasal mucosa presenting polyposis showed a significant reduction of CD133 levels, and also that this reduction was significantly correlated with the reduction of TGF-β1 levels, but not with IL-8 levels. Therefore, these findings may be involved in the altered inflammatory and remodeling processes observed in the nasal polyposis.

Locoregional delivery of stem cell-based therapies

Interventional regenerative medicine (IRM) uses image-guided, minimally invasive procedures for the targeted delivery of stem cell-based therapies to regenerate, replace, or repair damaged organs. Although many cellular therapies have shown promise in the preclinical setting, clinical results have been suboptimal. Most intravenously delivered cells become trapped in the lungs and reticuloendothelial system, resulting in little therapy reaching target tissues. IRM aims to increase the efficacy of cell-based therapies by locoregional stem cell delivery via endovascular, endoluminal, or direct injection into tissues. This review highlights routes of delivery, disease states, and mechanisms of action involved in the targeted delivery of stem cells.

Hematopoietic Stem Cells and Their Roles in Tissue Regeneration

Hematopoietic stem cells (HSCs) are regarded as one of essential cell sources for treating regenerative diseases. Among many stem cells, the feasibility of using adult-derived hematopoietic stem cells in therapeutic approaches is very diverse, and is unarguably regarded as an important cell source in stem cell biology. So far, many investigators are exploring HSCs and modified HSCs for use in clinical and basic science. In the present review, we briefly summarized HSCs and their application in pathophysiologic conditions, including non-hematopoietic tissue regeneration as well as blood disorders. HSCs and HSCs-derived progenitors are promising cell sources in regenerative medicine and their contributions can be properly applied to treat pathophysiologic conditions. Among many adult stem cells, HSCs are a powerful tool to treat patients with diseases such as hematologic malignancies and liver disease. Since HSCs can be differentiated into diverse progenitors including endothelial progenitors, they may be useful for constructing strategies for effective therapy.

Exploring the Most Promising Stem Cell Therapy in Liver Failure: A Systematic Review

Background

Alternative approaches to transplantation for liver failure are needed. One of the alternative approaches is stem cell therapy. However, stem cell therapy in liver failure is not standardized yet, as every centre have their own methods. This systematic review is aimed at compiling and analyzing the various studies that use stem cells to treat liver failure, to get an insight into potential protocols in terms of safety and efficacy by comparing them to controls.

Methods

This systematic review was done according to PRISMA guidelines and submitted for registration in PROSPERO (registration number CRD42018106119). All published studies in PubMed/MEDLINE and Cochrane Library, using key words: “human” and “stem cell” AND “liver failure” on 16^th June 2018, without time restriction. In addition, relevant articles that are found during full-text search were added. Inclusion criteria included all original articles on stem cell use in humans with liver failure. Data collected included study type, treatment and control number, severity of disease, concomitant therapy, type and source of cells, passage of cells, dose, administration route, repeats, and interval between repeats, outcomes, and adverse events compared to controls. Data were analyzed descriptively to determine the possible causes of adverse reactions, and which protocols gave a satisfactory outcome, in terms of safety and efficacy.

Results

There were 25 original articles, i.e., eight case studies and 17 studies with controls.

Conclusion

Among the various adult stem cells that were used in human studies, MSCs from the bone marrow or umbilical cord performed better compared to other types of adult stem cells, though no study showed a complete and sustainable performance in the outcome measures. Intravenous (IV) route was equal to invasive route. Fresh or cryopreserved, and autologous or allogeneic MSCs were equally beneficial; and giving too many cells via intraportal or the hepatic artery might be counterproductive.

Stem Cell Mobilization Is Lifesaving in a Large Animal Preclinical Model of Acute Liver Failure

INTRODUCTION

Acute liver failure (ALF) affects 2000 Americans each year with no treatment options other than liver transplantation. We showed previously that mobilization of endogenous stem cells is protective against ALF in rodents. The objective of this study was to assess whether stem cell mobilizing drugs are lifesaving in a large animal preclinical model of ALF, to assess readiness for a clinical trial.

METHODS

Male Yorkshire pigs (14-18 kg) were divided into 2 groups, control (n = 6) and treatment (n = 6). All pigs received an intravenous bolus of the hepatotoxin D-galactosamine (0.5 g/kg) via central line and were followed up until death or day 28. Treated animals received simultaneous intramuscular injection of plerixafor (1 mg/kg) and G-CSF (2 μg/kg) at baseline, 24 and 48 hours after toxin infusion to mobilize endogenous stem cells, as previously described. Control animals received saline.

RESULTS

All control animals (6/6) succumbed to liver failure within 91 hours, confirmed by clinical, biochemical, and histopathological evidence of ALF. In the treatment group (5/6) animals survived indefinitely despite comparable biochemical changes during the first 48 hours (P = 0.003). White blood cell count increased by a mean of 4× in the treated group at the peak of mobilization (P = 0.0004).

CONCLUSIONS

Stem cell mobilizing drugs were lifesaving in a preclinical large animal model of ALF. Since no therapeutic options other than liver transplantation are currently available for critically ill patients with ALF, a multicenter clinical trial is warranted.

Functions and the Emerging Role of the Foetal Liver into Regenerative Medicine

During foetal life, the liver plays the important roles of connection and transient hematopoietic function. Foetal liver cells develop in an environment called a hematopoietic stem cell niche composed of several cell types, where stem cells can proliferate and give rise to mature blood cells. Embryologically, at about the third week of gestation, the liver appears, and it grows rapidly from the fifth to 10th week under WNT/β-Catenin signaling pathway stimulation, which induces hepatic progenitor cells proliferation and differentiation into hepatocytes. Development of new strategies and identification of new cell sources should represent the main aim in liver regenerative medicine and cell therapy. Cells isolated from organs with endodermal origin, like the liver, bile ducts, and pancreas, could be preferable cell sources. Furthermore, stem cells isolated from these organs could be more susceptible to differentiate into mature liver cells after transplantation with respect to stem cells isolated from organs or tissues with a different embryological origin. The foetal liver possesses unique features given the co-existence of cells having endodermal and mesenchymal origin, and it could be highly available source candidate for regenerative medicine in both the liver and pancreas. Taking into account these advantages, the foetal liver can be the highest potential and available cell source for cell therapy regarding liver diseases and diabetes.

Protocol for MicroRNA Transfer into Adult Bone Marrow-derived Hematopoietic Stem Cells to Enable Cell Engineering Combined with Magnetic Targeting

While CD133⁺ hematopoietic stem cells (SCs) have been proven to provide high potential in the field of regenerative medicine, their low retention rates after injection into injured tissues as well as the observed massive cell death rates lead to very restricted therapeutic effects. To overcome these limitations, we sought to establish a non-viral based protocol for suitable cell engineering prior to their administration. The modification of human CD133⁺ expressing SCs using microRNA (miR) loaded magnetic polyplexes was addressed with respect to uptake efficiency and safety as well as the targeting potential of the cells. Relying on our protocol, we can achieve high miR uptake rates of 80-90% while the CD133⁺ stem cell properties remain unaffected. Moreover, these modified cells offer the option of magnetic targeting. We describe here a safe and highly efficient procedure for the modification of CD133⁺ SCs. We expect this approach to provide a standard technology for optimization of therapeutic stem cell effects and for monitoring of the administered cell product via magnetic resonance imaging (MRI).

Mesenchymal Stem Cell Transplantation for Liver Cell Failure: A New Direction and Option

Background and Aims

Mesenchymal stem cell transplantation (MSCT) became available with liver failure (LF), while the advantages of MSCs remain controversial. We aimed to assess clinical advantages of MSCT in patients with LF.

Methods

Clinical researches reporting MSCT in LF patients were searched and included.

Results

Nine articles (n = 476) related with LF patients were enrolled. After MSCT, alanine aminotransferase (ALT) baseline decreased largely at half a month (P < 0.05); total bilirubin (TBIL) baseline declined to a certain stable level of 78.57 μmol/L at 2 and 3 months (P < 0.05). Notably, the decreased value (D value) of Model for End-Stage Liver Disease score (MELD) of acute-on-chronic liver failure (ACLF) group was higher than that of chronic liver failure (CLF) group (14.93 ± 1.24 versus 4.6 ± 5.66, P < 0.05). Moreover, MELD baseline of ≥20 group was a higher D value of MELD than MELD baseline of <20 group with a significant statistical difference after MSCT (P = 0.003).

Conclusion

The early assessment of the efficacy of MSCT could be based on variations of ALT at half a month and TBIL at 2 and 3 months. And it had beneficial effects for patients with LF, especially in ACLF based on the D value of MELD.

Umbilical cord blood stem cells transplantation as an adjunctive treatment strategy for liver cirrhosis in Chinese population: a meta-analysis of effectiveness and safety

Objective

The aim of the study was to evaluate the efficacy and safety of umbilical cord blood stem cells (USCs) transplantation combined with routine supportive therapy (RST) for liver cirrhosis (LC).

Materials and methods

Clinical trials involved in this research were searched from Web of Science, PubMed, EMBASE, Cochrane Library, Wanfang and CNKI database. Treatment effects, quality of life (QoL), adverse events and other outcome measures were extracted and evaluated.

Results

A total of 10 trials including 616 LC patients were involved in this study. Based on our analysis, the liver function of LC patients was significantly improved after USCs transplantation and RST combined therapy, indicated by decreased total bilirubin, alanine aminotransferase, aspartate aminotransferase levels and prothrombin time and increased serum albumin level and prothrombin activity. Compared to those treated by RST alone, patients treated by combined therapy showed more satisfied treatment effects, improved QoL reflected by improved appetite (odds ratio [OR]=5.43, 95% CI=2.84 to 10.38, P<0.00001) and relieved fatigue (OR=4.33, 95% CI=0.87 to 21.60, P=0.07), ascetic fluid (OR=4.56, 95% CI=2.69 to 7.74, P<0.00001), abdominal distension (OR=4.01, 95% CI=1.34 to 12.02, P=0.01) and edema (OR=2.69, 95% CI=0.23 to 31.72, P=0.43). No serious adverse events occurred during USCs therapy.

Conclusion

USCs transplantation is a safe and effective adjuvant therapy for RST-treated LC, possibly through improving patients’ liver function.

Pharmacological Mobilization of Endogenous Bone Marrow Stem Cells Promotes Liver Regeneration after Extensive Liver Resection in Rats

Rapid regeneration of the remnant liver is critical for preventing liver failure and promoting recovery after extensive liver resection. Numerous studies have demonstrated the involvement of bone marrow-derived stem cells in liver regeneration and the potential benefits of bone marrow stem cell therapy. To avoid the preparation of stem cells, we proposed in this study to mobilize endogenous bone marrow stem cells pharmacologically with a combination of AMD3100 (A), an antagonist of CXCR4 and low-dose FK506 (F). Here we show that AF combination therapy significantly increased lineage negative (Lin-) CD34+ and Lin-CD133+ stem cells in peripheral blood and enhanced recruitment of CD133+ cells into the remnant liver in a rat model of 85% partial hepatectomy. Recruiting CD133+ stem cells in the remnant liver was associated with increased proliferation of hepatic oval cells and paralleled the increased SDF-1, CXCR4 and HGF expression. Importantly, AF combination therapy increased the number of Ki67 positive hepatocytes and BrdU incorporation in the remnant liver and improved serum levels of albumin. Our results demonstrate that pharmacological mobilization of endogenous bone marrow stem cells with AF combination therapy can enhance endogenous stem cell mobilization to promote liver regeneration and improve liver function after extensive hepatectomy.

Current Cell-Based Therapies in the Chronic Liver Diseases

Liver diseases account for one of the leading causes of deaths in global health care. Furthermore, chronic liver failure such as liver cirrhosis is, namely, responsible for these fatal conditions. However, only liver transplantation is an established treatment for this end-stage condition, although the availability of this salvage treatment option is quite limited. Thus, the novel therapy such as artificial liver devices or cellular administration has been regarded as feasible. Especially cellular therapies have been proposed in decades. The technical advancement and progress of understanding of cellular differentiation have contributed to the development of basis of cellular therapy. This attractive therapeutic option has been advanced from original embryonic stem cells to more effective cellular fractions such as Muse cells. Indeed several cellular therapies including bone marrow-derived stem cells or peripheral blood-derived stem cells were initiated; the recent most organized clinical trials could not demonstrate its efficacy. Thus, truly innovative cellular therapy is needed to meet the scientific demands, and Muse cell administration is the remaining approach to this. In this article, we will discuss the current development and status of cellular therapy toward chronic liver failure.

Challenges of running a GMP facility for regenerative medicine in a public hospital

Advanced therapy medicinal products represent a new generation of medicinal products for regenerative medicine. Since the implementation of the EU regulation for this innovative class of drugs, the academic and hospital institutions have played a central role in their development and manufacture. For these institutions that are not familiar with the industrial context, being in compliance with the pharmaceutical standards is extremely challenging. This report describes how we dealt with some specific issues during our hospital-based GMP experience. Furthermore, we identify as a future perspective the consistent stimulating contribution that a public entity can ensure for advanced therapy medicinal product development and licensing.

Molecular and functional characterization of CD133+ stem/progenitor cells infused in patients with end-stage liver disease reveals their interplay with stromal liver cells

BACKGROUND AIMS

Growing evidence supports the therapeutic potential of bone marrow (BM)-derived stem/progenitor cells for end-stage liver disease (ESLD). We recently demonstrated that CD133⁺ stem/progenitor cell (SPC) reinfusion in patients with ESLD is feasible and safe and improve, albeit transiently, liver function. However, the mechanism(s) through which BM-derived SPCs may improve liver function are not fully elucidated.

METHODS

Here, we characterized the circulating SPCs compartment of patients with ESLD undergoing CD133⁺ cell therapy. Next, we set up an in vitro model mimicking SPCs/liver microenvironment interaction by culturing granulocyte colony-stimulating factor (G-CSF)-mobilized CD133⁺and LX-2 hepatic stellate cells.

RESULTS

We found that patients with ESLD show normal basal levels of circulating hematopoietic and endothelial progenitors with impaired clonogenic ability. After G-CSF treatment, patients with ESLD were capable to mobilize significant numbers of functional multipotent SPCs, and interestingly, this was associated with increased levels of selected cytokines potentially facilitating SPC function. Co-culture experiments showed, at the molecular and functional levels, the bi-directional cross-talk between CD133⁺ SPCs and human hepatic stellate cells LX-2. Human hepatic stellate cells LX-2 showed reduced activation and fibrotic potential. In turn, hepatic stellate cells enhanced the proliferation and survival of CD133⁺ SPCs as well as their endothelial and hematopoietic function while promoting an anti-inflammatory profile.

DISCUSSION

We demonstrated that the interaction between CD133⁺ SPCs from patients with ESLD and hepatic stellate cells induces significant functional changes in both cellular types that may be instrumental for the improvement of liver function in cirrhotic patients undergoing cell therapy.

Cholangiocytes: Cell transplantation

BACKGROUND

Due to significant limitations to the access to orthotropic liver transplantation, cell therapies for liver diseases have gained large interest worldwide.

SCOPE OF REVIEW

To revise current literature dealing with cell therapy for liver diseases. We discussed the advantages and pitfalls of the different cell sources tested so far in clinical trials and the rationale underlying the potential benefits of transplantation of human biliary tree stem cells (hBTSCs).

MAJOR CONCLUSIONS

Transplantation of adult hepatocytes showed transient benefits but requires immune-suppression that is a major pitfall in patients with advanced liver diseases. Mesenchymal stem cells and hematopoietic stem cells transplanted into patients with liver diseases are not able to replace resident hepatocytes but rather they target autoimmune or inflammatory processes into the liver. Stem cells isolated from fetal or adult liver have been recently proposed as alternative cell sources for advanced liver cirrhosis and metabolic liver disease. We demonstrated the presence of multipotent cells expressing a variety of endodermal stem cell markers in (peri)-biliary glands of bile ducts in fetal or adult human tissues, and in crypts of gallbladder epithelium. In the first cirrhotic patients treated in our center with biliary tree stem cell therapy, we registered no adverse event but significant benefits.

GENERAL SIGNIFICANCE

The biliary tree stem cell could represent the ideal cell source for the cell therapy of liver diseases. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen.

Allogeneic bone marrow-derived mesenchymal stromal cells for hepatitis B virus-related acute-on-chronic liver failure: A randomized controlled trial

Mortality from hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF) is high due to limited treatment options. Preclinical and clinical investigations have proved that treatment with mesenchymal stromal cells (MSCs) is beneficial for recovery from liver injury. We hypothesized that the outcome of HBV-related ACLF would be improved by MSC treatment. From 2010 to 2013, 110 patients with HBV-related ACLF were enrolled in this open-label, nonblinded randomized controlled study. The control group (n = 54) was treated with standard medical therapy (SMT) only. The experimental group (n = 56) was infused weekly for 4 weeks with 1.0 to 10 × 10⁵ cells/kg allogeneic bone marrow-derived MSCs and then followed for 24 weeks. The cumulated survival rate of the MSC group was 73.2% (95% confidence interval 61.6%-84.8%) versus 55.6% (95% confidence interval 42.3%-68.9%) for the SMT group (P = 0.03). There were no infusion-related side effects, but fever was more frequent in MSC compared to SMT patients during weeks 5-24 of follow-up. No carcinoma occurred in any trial patient in either group. Compared with the control group, allogeneic bone marrow-derived MSC treatment markedly improved clinical laboratory measurements, including serum total bilirubin and Model for End-Stage Liver Disease scores. The incidence of severe infection in the MSC group was much lower than that in the SMT group (16.1% versus 33.3%, P = 0.04). Mortality from multiple organ failure and severe infection was higher in the SMT group than in the MSC group (37.0% versus 17.9%, P = 0.02).

CONCLUSION

Peripheral infusion of allogeneic bone marrow-derived MSCs is safe and convenient for patients with HBV-related ACLF and significantly increases the 24-week survival rate by improving liver function and decreasing the incidence of severe infections. (Hepatology 2017;66:209-219).

Magnet-Bead Based MicroRNA Delivery System to Modify CD133+ Stem Cells

Aim. CD133⁺ stem cells bear huge potential for regenerative medicine. However, low retention in the injured tissue and massive cell death reduce beneficial effects. In order to address these issues, we intended to develop a nonviral system for appropriate cell engineering. Materials and Methods. Modification of human CD133⁺ stem cells with magnetic polyplexes carrying microRNA was studied in terms of efficiency, safety, and targeting potential. Results. High microRNA uptake rates (~80-90%) were achieved without affecting CD133⁺ stem cell properties. Modified cells can be magnetically guided. Conclusion. We developed a safe and efficient protocol for CD133⁺ stem cell modification. Our work may become a basis to improve stem cell therapeutical effects as well as their monitoring with magnetic resonance imaging.

Stem/Progenitor Cell Niches Involved in Hepatic and Biliary Regeneration

Niches containing stem/progenitor cells are present in different anatomical locations along the human biliary tree and within liver acini. The most primitive stem/progenitors, biliary tree stem/progenitor cells (BTSCs), reside within peribiliary glands located throughout large extrahepatic and intrahepatic bile ducts. BTSCs are multipotent and can differentiate towards hepatic and pancreatic cell fates. These niches' matrix chemistry and other characteristics are undefined. Canals of Hering (bile ductules) are found periportally and contain hepatic stem/progenitor cells (HpSCs), participating in the renewal of small intrahepatic bile ducts and being precursors to hepatocytes and cholangiocytes. The niches also contain precursors to hepatic stellate cells and endothelia, macrophages, and have a matrix chemistry rich in hyaluronans, minimally sulfated proteoglycans, fetal collagens, and laminin. The microenvironment furnishes key signals driving HpSC activation and differentiation. Newly discovered third niches are pericentral within hepatic acini, contain Axin2+ unipotent hepatocytic progenitors linked on their lateral borders to endothelia forming the central vein, and contribute to normal turnover of mature hepatocytes. Their relationship to the other stem/progenitors is undefined. Stem/progenitor niches have important implications in regenerative medicine for the liver and biliary tree and in pathogenic processes leading to diseases of these tissues.