Feasibility and safety of autologous bone marrow mononuclear cell transplantation in patients with advanced chronic liver disease

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.

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.

Routes of Stem Cell Administration

Stem cells are very promising for the treatment of a plethora of human diseases. Numerous clinical studies have been conducted to assess the safety and efficacy of various stem cell types. Factors that ensure successful therapeutic outcomes in patients are cell-based parameters such as source, viability, and number, as well as frequency and timing of intervention and disease stage. Stem cell administration routes should be appropriately chosen as these can affect homing and engraftment of the cells and hence reduce therapeutic effects, or compromise safety, resulting in serious adverse events. In this chapter, we will describe the use of stem cells in organ repair and regeneration, in particular, the liver and the available routes of cell delivery in the clinic for end-stage liver diseases. Factors affecting homing and engraftment of stem cells for each administration route will be discussed.

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.

Treatment of AECHB and Severe Hepatitis (Liver Failure)

This chapter describes the general treatment and immune principles and internal management for AECHB and HBV ACLF, including ICU monitoring, general supportive medications/nutrition/nursing, immune therapy, artificial liver supportive systems, hepatocyte/stem cell, and liver transplant, management for special populations, frequently clinical complications and the utilization of Chinese traditional medicines.

Early clinical indicators of severe hepatitis B include acratia, gastrointestinal symptoms, a daily increase in serum bilirubin >1 mg/dL, toxic intestinal paralysis, bleeding tendency and mild mind anomaly or character change, and the presence of other diseases inducing severe hepatitis. Laboratory indicators include T-Bil, PTA, cholinesterase, pre-albumin and albumin. The roles of immune indicators (such as IL-6, TNF-α, and fgl2), gene polymorphisms, HBV genotypes, and gene mutations as early clinical indicators.

Intensive Care Unit monitor patients with severe hepatitis include intracranial pressure, infection, blood dynamics, respiratory function, renal function, blood coagulation function, nutritional status and blood purification process. Nursing care should not only include routine care, but psychological and special care (complications).

Nutrition support and nursing care should be maintained throughout treatment for severe hepatitis. Common methods of evaluating nutritional status include direct human body measurement, creatinine height index (CHI) and subject global assessment of nutrition (SGA). Malnourished patients should receive enteral or parenteral nutrition support.

Immune therapies for severe hepatitis include promoting hepatocyte regeneration (e.g. with glucagon, hepatocyte growth factor and prostaglandin E1), glucocorticoid suppressive therapy, and targeting molecular blocking. Corticosteroid treatment should be early and sufficient, and adverse drug reactions monitored. Treatments currently being investigated are those targeting Toll-like receptors, NK cell/NK cell receptors, macrophage/immune coagulation system, CTLA-4/PD-1 and stem cell transplantation.

In addition to conventional drugs and radioiodine, corticosteroids and artificial liver treatment can also be considered for severe hepatitis patients with hyperthyreosis. Patients with gestational severe hepatitis require preventive therapy for fetal growth restriction, and it is necessary to choose the timing and method of fetal delivery. For patients with both diabetes and severe hepatitis, insulin is preferred to oral antidiabetic agents to control blood glucose concentration. Liver toxicity of corticosteroids and immune suppressors should be monitored during treatment for severe hepatitis in patients with connective tissue diseases including SLE, RA and sicca syndrome. Patient with connective tissue diseases should preferably be started after the antiviral treatment with nucleos(t)ide analogues.

An artificial liver can improve patients’ liver function; remove endotoxins, blood ammonia and other toxins; correct amino acid metabolism and coagulation disorders; and reverse internal environment imbalances. Non-bioartificial livers are suitable for patients with early and middle stage severe hepatitis; for late-stage patients waiting for liver transplantation; and for transplanted patients with rejection reaction or transplant failure. The type of artificial liver should be determined by each patient’s condition and previous treatment purpose, and patients should be closely monitored for adverse reactions and complications. Bio- and hybrid artificial livers are still under development.

MELD score is the international standard for choosing liver transplantation. Surgical methods mainly include the in situ classic type and the piggyback type; transplantation includes no liver prophase, no liver phase or new liver phase. Preoperative preparation, management of intraoperative and postoperative complications and postoperative long-term treatment are keys to success.

Severe hepatitis belongs to the categories of “acute jaundice”, “scourge jaundice”, and “hot liver” in traditional Chinese medicine. Treatment methods include Chinese traditional medicines, acupuncture and acupoint injection, external application of drugs, umbilical compress therapy, drip, blow nose therapy, earpins, and clysis. Dietary care is also an important part of traditional Chinese medicine treatment.

Repeated Autologous Bone Marrow Transfusion through Portal Vein for Treating Decompensated Liver Cirrhosis after Splenectomy

Objective

This study is aimed at examining the impact of repeated intraportal autologous bone marrow transfusion (ABMT) in patients with decompensated liver cirrhosis after splenectomy.

Methods

A total of 25 patients with decompensated liver cirrhosis undergoing splenectomy were divided into ABMT and control groups. The portal vein was cannulated intraoperatively using Celsite Implantofix through the right gastroomental vein. Both groups were given a routine medical treatment. Then, 18 mL of autologous bone marrow was transfused through the port in the patients of the ABMT group 1 week, 1 month, and 3 months after laminectomy, while nothing was given to the control group. All patients were monitored for adverse events. Liver function tests, including serum albumin (ALB), alanine aminotransferase (ALT), total bilirubin (TB), prothrombin activity (PTA), cholinesterase (CHE), α-fetoprotein (AFP), and liver stiffness measurement (LSM), were conducted before surgery and 1, 3, and 6 months after surgery.

Results

Significant improvements in ALB, ALT, and CHE levels and decreased LSM were observed in the ABMT group compared with those in the control group (P < 0.05). TB and PTA improved in both groups but with no significant differences between the groups. No significant changes were observed in AFP in the control group, but it decreased in the ABMT group. No major adverse effects were noted during the follow-up period in the patients of either group.

Conclusions

Repeated intraportal ABMT was clinically safe, and liver function of patients significantly improved. Therefore, this therapy has the potential to treat patients with decompensated liver cirrhosis after splenectomy. This trial was registered with the identification number of ChiCTR-ONC-17012592.

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.

Mesenchymal stem cell therapy for advanced liver cirrhosis: A case report

Mesenchymal stem cell (MSC) transplant may offer an alternative to liver transplantation in patients with end‐stage liver disease. However, its efficacy remains uncertain. MSC was performed on a 50‐year‐old male with decompensated (Child‐Turcotte‐Pugh grade C) alcoholic liver cirrhosis due to an absence of donors for adult‐deceased and living‐related liver transplantation. Autologous bone marrow‐derived MSCs were harvested from the patient and cultured using standard protocols. The MSCs were subsequently re‐administrated into the liver via hepatic intra‐arterial infusion on two separate occasions. After infusion, there was an improvement in biochemical parameters (serum total bilirubin, serum albumin), and a reduction of diuretic use for ascites for up to 8 weeks. However, all biochemical and clinical parameters deteriorated on long‐term follow‐up without any further infusions. The patient eventually succumbed to his disease. MSC transplantation may have a clinical benefit on adult patients with end‐stage liver cirrhosis, but this appears to be transitory.

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.

Long-Term Follow-Up of Patients After Autologous Bone Marrow Cell Infusion for Decompensated Liver Cirrhosis

Although several human clinical trials using various bone marrow-derived cell types for cirrhotic or decompensated patients have reported a short-term benefit, long-term follow-up data are limited. We analyzed the long-term clinical outcomes of autologous bone marrow cell infusion (ABMI) for decompensated liver cirrhosis (LC). Patients enrolled in a pilot single-armed ABMI study were followed up more than 5 years. Bone marrow-derived mononuclear cells (BM-MNCs) from decompensated LC were harvested and after processing were infused into a peripheral vein. The laboratory test results and long-term clinical course including liver transplantation (LT), development of cancer, cause of death, and survival after ABMI were analyzed. Nineteen patients were followed up for a median of 66 months after ABMI. Liver function, including serum levels of albumin and Child-Pugh (CP) score, was improved at the 1-year follow-up. Liver volume was significantly greater, cirrhosis was sustained, and collagen content was decreased at the 6-month follow-up. Five years after ABMI, five patients (26.3%) maintained CP class A without LT or death, and five patients (26.3%) had undergone elective LT. Hepatocellular carcinoma (HCC) occurred in five patients (26.3%), and lymphoma and colon cancer occurred in one patient each. Three patients (15.8%) were lost to follow-up at months 22, 31, and 33, respectively, but maintained CP class A until their last follow-up. Five patients expired due to infection. While improved liver function was maintained in some patients for more than 5 years after ABMI, other patients developed HCC. Further studies of long-term follow-up cohorts after cell therapy for LC are warranted.

Cell transplantation as a non-invasive strategy for treating liver fibrosis

Advancements in antiviral drugs have enabled control of viral hepatitis; yet, many patients with liver cirrhosis (LC) are awaiting liver transplants. Liver transplantation yields dramatic therapeutic effects, but problems such as shortage of donors, surgical invasiveness, immunological rejection and costs, limit the number of transplantations. Advances in liver regeneration therapy through cell transplantation as a non-invasive treatment for cirrhosis will supplement these restrictions to the number of liver transplants. Clinical trials for LC have included hematopoietic stem cell mobilization by administration of granulocyte colony-stimulating factor, infusion of autologous bone marrow cells, and administration of autologous mesenchymal stem cells derived from bone marrow or umbilical cord. Several recently reported randomized controlled studies have shown the effectiveness of these approaches. However, to promote implementation of new liver regeneration therapies, it is important to develop a system whereby cell therapies with ensured safety can be approved quickly.

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

BACKGROUND

Bone marrow stem/progenitor cells seem to be effective in liver regeneration after tissue injury.

AIM

To evaluate the feasibility and safety of the mobilization and reinfusion of CD133+ stem/progenitor cells in patients with end-stage liver disease.

METHODS

Autologous CD133+ stem/progenitor cells, mobilized with granulocyte-colony stimulating factor, were collected by leukapheresis and reinfused at increasing doses through the hepatic artery starting from 5×10(4)/kg up to 1×10(6)/kg.

RESULTS

16 subjects with Model for End-stage Liver Disease (MELD) score between 17 and 25 were enrolled, 14 mobilized an adequate number of CD133+ stem/progenitor cells and 12 were reinfused. No severe adverse events related to the procedure were reported. MELD score significantly worsened during mobilization in Child Turcotte Pugh-C patients. A significant improvement of liver function was observed 2 months after reinfusion (MELD 19.5 vs. 16; P=0.045). Overall, 5 patients underwent liver transplantation within 12 months from reinfusion and 2 died because of progressive liver failure.

CONCLUSIONS

CD133+ stem/progenitor cells reinfusion in patients with end-stage liver disease is feasible and safe. A worsening of liver function was observed during mobilization in Child Turcotte Pugh-C patients. The temporary improvement of MELD score after reinfusion suggests that stem cells therapy may be a "bridge to transplant" approach for these patients.

Murine Sca1(+)Lin(-) bone marrow contains an endodermal precursor population that differentiates into hepatocytes

The direct differentiation of hepatocytes from bone marrow cells remains controversial. Several mechanisms, including transdifferentiation and cell fusion, have been proposed for this phenomenon, although direct visualization of the process and the underlying mechanisms have not been reported. In this study, we established an efficient in vitro culture method for differentiation of functioning hepatocytes from murine lineage-negative bone marrow cells. These cells reduced liver damage and incorporated into hepatic parenchyma in two independent hepatic injury models. Our simple and efficient in vitro protocol for endodermal precursor cell survival and expansion enabled us to identify these cells as existing in Sca1⁺ subpopulations of lineage-negative bone marrow cells. The endodermal precursor cells followed a sequential developmental pathway that included endodermal cells and hepatocyte precursor cells, which indicates that lineage-negative bone marrow cells contain more diverse multipotent stem cells than considered previously. The presence of equivalent endodermal precursor populations in human bone marrow would facilitate the development of these cells into an effective treatment modality for chronic liver diseases.

Mesenchymal stem cell therapy for cirrhosis: Present and future perspectives

Cirrhosis occurs as a result of various chronic liver injuries, which may be caused by viral infections, alcohol abuse and the administration of drugs and chemicals. Recently, bone marrow cells (BMCs), hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs) have been used for developing treatments for cirrhosis. Clinical trials have investigated the therapeutic potential of BMCs, HSCs and MSCs for the treatment of cirrhosis based on their potential to differentiate into hepatocytes. Although the therapeutic mechanisms of BMC, HSC and MSC treatments are still not fully characterized, the evidence thus far has indicated that the potential therapeutic mechanisms of MSCs are clearer than those of BMCs or HSCs with respect to liver regenerative medicine. MSCs suppress inflammatory responses, reduce hepatocyte apoptosis, increase hepatocyte regeneration, reverse liver fibrosis and enhance liver functionality. This paper summarizes the clinical studies that have used BMCs, HSCs and MSCs in patients with liver failure or cirrhosis. We also present the potential therapeutic mechanisms of BMCs, HSCs and MSCs for the improvement of liver function.

Clinical therapeutic effects of human umbilical cord-derived mesenchymal stem cells transplantation in the treatment of end-stage liver disease

We aimed to evaluate clinical therapeutic effects of human umbilical cord-derived mesenchymal stem cell (UCMSC) transplantation in the treatment of end-stage liver diseases. The human UCMSCs were cultured and prepared, and then transplanted into the hepatic tissues of 50 patients with decompensated cirrhosis. The liver function, thrombin function, Model for End-Stage Liver Disease (MELD) score, and hemodynamic index value were detected during a 24-week follow-up period, with the addition of hepatoprotective, antiviral, and other conventional treatments. No complications or serious side effects were observed. In the first 2-3 weeks after surgery, symptoms including abdominal distension, oliguria, edema, and others decreased significantly, with increased appetite compared with before surgery. In the 24-week follow-up period, the levels of serum albumin and prealbumin increased significantly compared with the preoperative levels; the decrease of coagulation indicators was not significant. The MELD scores were also markedly increased. Alpha-fetoprotein levels increased without significance after treatment. There was no significant difference in the hemodynamic changes in the portal and splenic veins according to ultrasound. Moreover, no significant differences in the liver and thrombin functions between the hepatitis B virus group and the other-etiology group were observed.

Natural Killer Cells-Produced IFN-γ Improves Bone Marrow-Derived Hepatocytes Regeneration in Murine Liver Failure Model

Bone-marrow transplantation (BMT) can repopulate the liver through BM-derived hepatocyte (BMDH) generation, although the underlying mechanism remains unclear. Using fumarylacetoacetate hydrolase-deficient (Fah(-/-)) mice as a liver-failure model, we confirmed that BMDHs were generated by fusion of BM-derived CD11b(+)F4/80(+)myelomonocytes with resident Fah(-/-) hepatocytes. Hepatic NK cells became activated during BMDH generation and were the major IFN-γ producers. Indeed, both NK cells and IFN-γ were required for BMDH generation since WT, but not NK-, IFN-γ-, or IFN-γR1-deficient BM transplantation successfully generated BMDHs and rescued survival in Fah(-/-) hosts. BM-derived myelomonocytes were determined to be the IFN-γ-responding cells. The IFN-γ-IFN-γR interaction contributed to the myelomonocyte-hepatocyte fusion process, as most of the CD11b(+) BMDHs in mixed BM chimeric Fah(-/-) hosts transplanted with a 1:1 ratio of CD45.1(+) WT and CD45.2(+) Ifngr1(-/-) BM cells were of CD45.1(+) WT origin. Confirming these findings in vitro, IFN-γ dose-dependently promoted the fusion of GFP(+) myelomonocytes with Fah(-/-) hepatocytes due to a direct effect on myelomonocytes; similar results were observed using activated NK cells. In conclusion, BMDH generation requires NK cells to facilitate myelomonocyte-hepatocyte fusion in an IFN-γ-dependent manner, providing new insights for treating severe liver failure.

The hematopoietic system in the context of regenerative medicine

Hematopoietic stem cells (HSC) represent the prototype stem cell within the body. Since their discovery, HSC have been the focus of intensive research, and have proven invaluable clinically to restore hematopoiesis following inadvertent radiation exposure and following radio/chemotherapy to eliminate hematologic tumors. While they were originally discovered in the bone marrow, HSC can also be isolated from umbilical cord blood and can be "mobilized" peripheral blood, making them readily available in relatively large quantities. While their ability to repopulate the entire hematopoietic system would already guarantee HSC a valuable place in regenerative medicine, the finding that hematopoietic chimerism can induce immunological tolerance to solid organs and correct autoimmune diseases has dramatically broadened their clinical utility. The demonstration that these cells, through a variety of mechanisms, can also promote repair/regeneration of non-hematopoietic tissues as diverse as liver, heart, and brain has further increased their clinical value. The goal of this review is to provide the reader with a brief glimpse into the remarkable potential HSC possess, and to highlight their tremendous value as therapeutics in regenerative medicine.

Hepatic regenerative potential of mouse bone marrow very small embryonic-like stem cells

Very small embryonic-like stem cells (VSELs) are a Sca-1 (+)  Lin(-) CD45(-) cell population that has been isolated from the bone marrow of mice. The similarities and differences between the mRNA profiles of VSELs and embryonic stem (ES) cells have not yet been defined. Here, we report the whole genome gene expression profile of VSELs and ES cells. We analyzed the global gene expression of VSELs and compared it with ES cells by microarray analysis. We observed that 9,521 genes are expressed in both VSELs and ES cells, 1,159 genes are expressed uniquely in VSELs, and 420 genes are expressed uniquely in ES cells. We found that although VSELs are similar to ES cells in their expression of genes associated with stem cell behavior and pluripotency, there are also differences in their mRNA expression. We further analyzed the expression of stem cell-associated genes in VSELs and ES cells, and found that there were differences in these genes. For instance, the Pkd2 and Yap1 gene were reduced in their expression in VSELs when compared with ES cells. But we also found Zfp54 gene expression was higher in VSELs compared with ES cells. More interestingly, we demonstrated that VSELs express c-kit, the stem cell factor (SCF) receptor. In vitro, SCF promoted VSEL differentiation into hepatic colonies in the presence of hepatocyte growth factor. In vivo, transplantation of VSELs directly into CCl4-induced injured livers significantly reduced serum ALT and AST levels. Therefore, these data suggest that VSELs play a role in the repair of injured livers.

Cell-based therapy approaches: the hope for incurable diseases

Cell therapies aim to repair the mechanisms underlying disease initiation and progression, achieved through trophic effect or by cell replacement. Multiple cell types can be utilized in such therapies, including stem, progenitor or primary cells. This review covers the current state of cell therapies designed for the prominent disorders, including cardiovascular, neurological (Parkinson's disease, amyotrophic lateral sclerosis, stroke, spinal cord injury), autoimmune (Type 1 diabetes, multiple sclerosis, Crohn's disease), ophthalmologic, renal, liver and skeletal (osteoarthritis) diseases. Various cell therapies have reached advanced clinical trial phases with potential marketing approvals in the near future, many of which are based on mesenchymal stem cells. Advances in pluripotent stem cell research hold great promise for regenerative medicine. The information presented in this review is based on the analysis of the cell therapy collection detailed in LifeMap Discovery(®) (LifeMap Sciences Inc., USA) the database of embryonic development, stem cell research and regenerative medicine.

REpeated AutoLogous Infusions of STem cells In Cirrhosis (REALISTIC): a multicentre, phase II, open-label, randomised controlled trial of repeated autologous infusions of granulocyte colony-stimulating factor (GCSF) mobilised CD133+ bone marrow stem cells in patients with cirrhosis. A study protocol for a randomised controlled trial

INTRODUCTION

Liver disease mortality and morbidity are rapidly rising and liver transplantation is limited by organ availability. Small scale human studies have shown that stem cell therapy is safe and feasible and has suggested clinical benefit. No published studies have yet examined the effect of stem cell therapy in a randomised controlled trial and evaluated the effect of repeated therapy.

METHODS AND ANALYSIS

Patients with liver cirrhosis will be randomised to one of three trial groups: group 1: Control group, Standard conservative management; group 2 treatment: granulocyte colony-stimulating factor (G-CSF; lenograstim) 15 µg/kg body weight daily on days 1-5; group 3 treatment: G-CSF 15 µg/kg body weight daily on days 1-5 followed by leukapheresis, isolation and aliquoting of CD133+ cells. Patients will receive an infusion of freshly isolated CD133+ cells immediately and frozen doses at days 30 and 60 via peripheral vein (0.2×10(6) cells/kg for each of the three doses). Primary objective is to demonstrate an improvement in the severity of liver disease over 3 months using either G-CSF alone or G-CSF followed by repeated infusions of haematopoietic stem cells compared with standard conservative management. The trial is powered to answer two hypotheses of each treatment compared to control but not powered to detect smaller expected differences between the two treatment groups. As such, the overall α=0.05 for the trial is split equally between the two hypotheses. Conventionally, to detect a relevant standardised effect size of 0.8 point reduction in Model for End-stage Liver Disease score using two-sided α=0.05(overall α=0.1 split equally between the two hypotheses) and 80% power requires 27 participants to be randomised per group (81 participants in total).

ETHICS AND DISSEMINATION

The trial is registered at Current Controlled Trials on 18 November 2009 (ISRCTN number 91288089, EuDRACT number 2009-010335-41). The findings of this trial will be disseminated to patients and through peer-reviewed publications and international presentations.

Autologous bone marrow-derived cells in the treatment of liver disease patients

Liver transplantation is universally accepted as a "cure" procedure, and yet is not universally applicable for the treatment of end-stage liver diseases (ESLD) because of the shortage of donors, operative complications, risk of rejection, and high cost. Bioartificial liver device is an option to temporarily improve the liver function and to bridge the patients to liver transplantation. However, bioartificial liver device has many problems in clinical application, such as hepatocyte allograft rejection and maintenance of hepatocyte viability and function. Another therapeutic option is stem cell transplantation. There are two broad types of stem cells: Embryonic stem cells and adult stem cells. The latter are sourced from bone marrow (BM), adipose tissue, and blood. This review will concentrate on BM-derived cells. BM-derived cell transplantation, although not ideal, is theoretically an optimal modality for the treatment of ESLD. Autologous BM-derived cells have no graft rejection, have the capability of regeneration and self-renewal, and are multipotent stem cells that can differentiate into a variety of cell types which include hepatocytes. The pathway from BM-derived cell to hepatocyte is well documented. The present review summarizes the delivery routes of BM-derived cells to the liver, the evidences of engraftment of BM-derived cells in the liver, and the possible mechanisms of BM-derived cells in liver repair and regeneration, and finally, updates the clinical applications.

CD34(+) cell therapy is safe and effective in slowing the decline of hepatic reserve function in patients with decompensated liver cirrhosis

BACKGROUND AND AIM

Preclinical studies in rodent models of chronic liver fibrosis have shown that transplantation of peripheral blood (PB) CD34(+) cells leads to hepatic regeneration and a reduction of liver fibrosis by suppressing hepatic stellate cell activity and increasing matrix metalloproteinase activity. The aim of this study was to examine the safety and clinical efficacy of intrahepatic transplantation of autologous granulocyte colony-stimulating factor (G-CSF)-mobilized PB-CD34(+) cells in patients with decompensated liver cirrhosis.

METHODS

PB-CD34(+) cells were isolated from G-CSF-mobilized apheresis products. Ten patients were treated with G-CSF-mobilized PB-CD34(+) cells (treatment group) and seven patients were treated with standard medical therapy. For mobilization, patients in the treatment group received subcutaneous injections of 10 μg G-CSF/kg/day for 5 days. The cells were then injected at three different doses (5 × 10(5) , 1 × 10(6) and 2 × 10(6) cells/kg) through the hepatic artery. Thereafter, all patients were followed up for 24 months.

RESULTS

G-CSF treatment and leukapheresis were well tolerated, and no serious adverse events were observed. Patients in the treatment group had a significant but transient splenomegaly. After 24 weeks, serum albumin was significantly increased in patients who had received middle or high doses of CD34(+) cells compared with baseline. Doppler ultrasound showed a significant increase in hepatic blood flow velocity and blood flow volume after CD34(+) cell therapy. The hepatic vein pressure gradient decreased in two patients who received high-dose CD34(+) cells at week 16.

CONCLUSIONS

CD34(+) cell therapy is feasible, safe and effective in slowing the decline of hepatic reserve function.

Concise review: bone marrow autotransplants for liver disease?

There are increasing reports of using bone marrow-derived stem cells to treat advanced liver disease. We consider several critical issues that underlie this approach. For example, are there multipotent stem cell populations in human adult bone marrow? Can they develop into liver cells or supporting cell types? What are stromal stem/progenitor cells, and can they promote tissue repair without replacing hepatocytes? Does reversal of end-stage liver disease require new hepatocytes, a new liver microenvironment, both, neither or something else? Although many of these questions are unanswered, we consider the conceptual and experimental bases underlying these issues and critically analyze results of clinical trials of stem cell therapy of end-stage liver disease.

Bone marrow-derived stromal cell therapy in cirrhosis: clinical evidence, cellular mechanisms, and implications for the treatment of hepatocellular carcinoma

Current treatment options for hepatocellular carcinoma (HCC) are often limited by the presence of underlying liver disease. In patients with liver cirrhosis, surgery, chemotherapy, and radiation therapy all carry a high risk of hepatic complications, ranging from ascites to fulminant liver failure. For patients receiving radiation therapy, cirrhosis dramatically reduces the already limited radiation tolerance of the liver and represents the most important clinical risk factor for the development of radiation-induced liver disease. Although improvements in conformal radiation delivery techniques have improved our ability to safely irradiate confined areas of the liver to increasingly higher doses with excellent local disease control, patients with moderate-to-severe liver cirrhosis continue to face a shortage of treatment options for HCC. In recent years, evidence has emerged supporting the use of bone marrow-derived stromal cells (BMSCs) as a promising treatment for liver cirrhosis, with several clinical studies demonstrating sustained improvement in clinical parameters of liver function after autologous BMSC infusion. Three predominant populations of BMSCs, namely hematopoietic stem cells, mesenchymal stem cells, and endothelial progenitor cells, seem to have therapeutic potential in liver injury and cirrhosis. Preclinical studies of BMSC transplantation have identified a range of mechanisms through which these cells mediate their therapeutic effects, including hepatocyte transdifferentiation and fusion, paracrine stimulation of hepatocyte proliferation, inhibition of activated hepatic stellate cells, enhancement of fibrolytic matrix metalloproteinase activity, and neovascularization of regenerating liver. By bolstering liver function in patients with underlying Child's B or C cirrhosis, autologous BMSC infusion holds great promise as a therapy to improve the safety, efficacy, and utility of surgery, chemotherapy, and hepatic radiation therapy in the treatment of HCC.

Randomized trial of autologous bone marrow mesenchymal stem cells transplantation for hepatitis B virus cirrhosis: regulation of Treg/Th17 cells

BACKGROUND AND AIM

Liver cirrhosis is one of the major consequences of hepatitis B virus (HBV) infection, and transplantation of autologous bone marrow mesenchymal stem cells (ABMSCs) is one of promising therapies for patients with HBV-related liver cirrhosis (HBV-LC). However, the mechanism is unclear. The aim of the current study was to explore the role of Treg/Th17 cells in ABMSCs transplantation in patients with HBV-LC.

METHODS

In this prospective study, 56 patients were enrolled and randomly assigned to transplantation group and control group. After 24-week follow-up, 39 patients completed the study (20 cases in transplantation group and 19 cases in control group). The Model for End-Stage Liver Disease scores, liver function, changes of Treg/Th17 cells, as well as related transcription factors and serum cytokines, were determined.

RESULTS

Although patients in both groups showed significant improvement after Entecavir treatment, ABMSC transplantation further improved patients' liver function. Moreover, there was a significant increase in Treg cells and a marked decrease in Th17 cells in the transplantation group compared with control, leading to an increased Treg/Th17 ratio. Furthermore, mRNA levels of Treg-related transcription factor (Foxp3) and Th17-related transcription factor (RORγt) were increased and decreased, respectively. In addition, serum transforming growth factor-β levels were significantly higher at early weeks of transplantation, while serum levels of interleukin-17, tumor necrosis factor-α, and interleukin-6 were significantly lower in patients in the transplantation group compared with control.

CONCLUSION

ABMSCs transplantation was effective in improving liver function in patients with HBV-LC, which was mediated, at least in part, through the regulation of Treg/Th17 cell balance.

Bone marrow stem cell therapy for liver disease

Liver disease is a rising cause of mortality and morbidity, and treatment options remain limited. Liver transplantation is curative but limited by donor organ availability, operative risk and long-term complications. The contribution of bone marrow (BM)-derived stem cells to tissue regeneration has been recognised and there is considerable interest in the potential benefits of BM stem cells in patients with liver disease. In chronic liver disease, deposition of fibrous scar tissue inhibits hepatocyte proliferation and leads to portal hypertension. Although initial reports had suggested transdifferentiation of stem cells into hepatocytes, the beneficial effects of BM stem cells are more likely derived from the ability to breakdown scar tissue and stimulate hepatocyte proliferation. Studies in animal models have yielded promising results, although the exact mechanisms and cell type responsible have yet to be determined. Small-scale clinical studies have quickly followed and, although primarily designed to examine safety and feasibility of this approach, have reported improvements in liver function in treated patients. Well-designed, controlled studies are required to fully determine the benefits of BM stem cell therapy.

Immunological basis of stem cell therapy in liver diseases

Unbalanced immune cell populations or immune cell infiltration of the liver can disrupt the immune-privileged state of the liver, resulting in liver injury or fibrosis. Therefore, the treatment for liver diseases involves not only hepatic regeneration but also immunological regulation. Recent studies demonstrated that stem cells, especially mesenchymal stem cells, have the capacity for not only hepatic differentiation but also immunomodulation. In this respect, stem cell therapy could be a realistic aim for liver diseases by modulating the liver regenerative processes and down-regulating immune-mediated liver damage. In this review, we discuss in detail the importance of immune cells in liver injury and repair; the mechanism by which stem cells demonstrate an immune-tolerant phenotype that can be used for allogeneic transplantation; the effect of stem cell transplantation on immune-mediated diseases, especially liver diseases; and the mechanism by which stem cells improve the hepatic microenvironment.

Peripheral vein infusion of autologous mesenchymal stem cells in Egyptian HCV-positive patients with end-stage liver disease

Introduction

We have assessed the utility of autologous mesenchymal stem cell (MSC) peripheral vein infusion as a possible therapeutic modality for patients with end-stage liver diseases.

Methods

Forty patients with post-hepatitis C virus (HCV) end-stage liver disease were randomized into two groups: Group 1 (GI): 20 patients who received granulocyte colony-stimulating factor (G-CSF) for 5 days followed by autologous MSCs peripheral-vein infusion and group 2 (GII): 20 patients who received regular liver-supportive treatment only (control group).

Results

In MSC-infused patients (GI), 54% showed near normalization of liver enzymes and improvement in liver synthetic function. Significant changes were reported in albumin (P = 0.000), bilirubin (P = 0.002), increased international normalized ratio (INR) (P = 0.017), prothrombin concentration (P = 0.029) and alanine transaminase (ALT) levels (P = 0.029), with stabilization of clinical and biochemical status in 13% of cases. None of the patients in GII showed any significant improvement. Hepatic fibrosis was assessed in GI by detection of procollagen IIIC peptide level (PIIICP) and procollagen III N peptide level (PIIINP). The pretreatment values of s-PIIICP and s-PIIINP were 9.4 ± 4.2 and 440 ± 189, respectively, with a decrease to 8.1 ± 2.6 and 388 ± 102, respectively, 3 months after MSC therapy. However, the difference was statistically nonsignificant (P = 0.7). A significant correlation coefficient was reported after 3 months between the s-PIIINP and prothrombin concentration (P = -0.5) and between s-PIIICP and ascites (P = 0.550).

Conclusions

First, autologous MSC infusion into a peripheral vein is as effective as the previously reported intrahepatic infusion. Second, MSCs have a supportive role in the treatment of end-stage liver disease, with satisfactory tolerability and beneficial effects on liver synthetic functions and hepatic fibrosis. Third, IV infusion of MSCs after G-CSF mobilization improves s-albumin within the first 2 weeks and prothrombin concentration and alanine Taransaminase after 1 month. According to the data from this current study and those previously reported by our group, we recommend further studies on patients’ infusion with pure CD133 and CD34 followed by IV infusion of in vitro-differentiated MSCs within 1 week and another infusion after 3 months.

Trial registration

ClinicalTrials.gov NCT01729221. Registered 17 November 2012.

Stem cells in liver regeneration and their potential clinical applications

Stem cells constitute a population of "primitive cells" with the ability to divide indefinitely and give rise to specialized cells under special conditions. Because of these two characteristics they have received particular attention in recent decades. These cells are the primarily responsible factors for the regeneration of tissues and organs and for the healing of lesions, a feature that makes them a central key in the development of cell-based medicine, called Regenerative Medicine. The idea of wound and organ repair and body regeneration is as old as the mankind, reflecting the human desire for inhibiting aging and immortality and it is first described in the ancient Greek myth of Prometheus. It is of interest that the myth refers to liver, an organ with remarkable regenerative ability after loss of mass and function caused by liver injury or surgical resection. Over the last decade there has been an important progress in understanding liver physiology and the mechanisms underlying hepatic development and regeneration. As liver transplantation, despite its difficulties, remains the only effective therapy for advanced liver disease so far, scientific interest has nowadays been orientated towards Regenerative Medicine and the use of stem cells to repair damaged liver. This review is focused on the available literature concerning the role of stem cells in liver regeneration. It summarizes the results of studies concerning endogenous liver regeneration and stem cell experimental protocols. Moreover, this review discusses the clinical studies that have been conducted in humans so far.

Systematic review: the effects of autologous stem cell therapy for patients with liver disease

BACKGROUND

As morbidity and mortality from liver disease continues to rise, new strategies are necessary. Liver transplantation is not only an expensive resource committing the patient to lifelong immunosuppression but also suitable donor organs are in short supply. Against this background, autologous stem cell therapy has emerged as a potential treatment option.

AIM

To evaluate if it is possible to make a judgement on the safety, feasibility and effect of autologous stem cell therapy for patients with liver disease.

METHODS

MEDLINE and EMBASE were searched up until July 2013 to identify studies where autologous stem cell therapy was administered to patients with liver disease.

RESULTS

Of 1668 studies identified, 33 were eligible for inclusion evaluating a median sample size of 10 patients for a median follow-up of 6 months. Although there was marked heterogeneity between studies with regards to type, dose and route of delivery of stem cell, the treatment was shown to be safe and feasible largely when a peripheral route of administration was used. Of the studies which also looked at biochemical outcome, statistically significant improvement in liver function tests was seen in 16 studies post-treatment.

CONCLUSION

Although autologous stem cell therapy is a much needed possibility in the treatment of liver disease, further robust clinical trials and collaborative protocols are required.

Cellular therapy for liver disease

Regenerative medicine is energizing and empowering basic science and has the potential to dramatically transform health care in the future. Given the remarkable intrinsic regenerative properties of the liver, as well as widespread adoption of regenerative strategies for liver disease (eg, liver transplant, partial hepatectomy, living donor transplant), hepatology has always been at the forefront of clinical regenerative medicine. However, an expanding pool of patients awaiting liver transplant, a limited pool of donor organs, and finite applicability of the current surgical approaches have created a need for more refined and widely available regenerative medicine strategies. Although cell-based therapies have been used extensively for hematologic malignant diseases and other conditions, the potential application of cellular therapy for acute and chronic liver diseases has only more recently been explored. New understanding of the mechanisms of liver regeneration and repair, including activation of local stem/progenitor cells and contributions from circulating bone marrow-derived stem cells, provide the theoretical underpinnings for the rational use of cell-based therapies in clinical trials. In this review, we dissect the scientific rationale for various modalities of cell therapy for liver diseases being explored in animal models and review those tested in human clinical trials. We also attempt to clarify some of the important ongoing questions that need to be addressed in order to bring these powerful therapies to clinical translation. Discussions will cover transplant of hepatocytes and liver stem/progenitor cells as well as infusion or stimulation of bone marrow-derived stem cells. We also highlight tremendous scientific advances on the horizon, including the potential use of induced pluripotent stem cells and their derivatives as individualized regenerative therapy for liver disease.

Bone marrow cell-based regenerative therapy for liver cirrhosis

Bone marrow cells are capable of differentiation into liver cells. Therefore, transplantation of bone marrow cells has considerable potential as a future therapy for regeneration of damaged liver tissue. Autologous bone marrow infusion therapy has been applied to patients with liver cirrhosis, and improvement of liver function parameters has been demonstrated. In this review, we summarize clinical trials of regenerative therapy using bone marrow cells for advanced liver diseases including cirrhosis, as well as topics pertaining to basic in vitro or in vivo approaches in order to outline the essentials of this novel treatment modality.

Transplantation of mesenchymal stem cells for the treatment of liver diseases, is there enough evidence?

Mesenchymal stem cells or multipotent mesenchymal stromal cells (MSCs) have been extensively investigated in small animal models to treat both acute and chronic liver injuries. Mechanisms of action are not clearly elucidated but may include their ability to differentiate into hepatocyte-like cells, to reduce inflammation, and to enhance tissue repair at the site of injury. This approach is controversial and evidence in large animals is missing. Side effects of MSC infusion such as the contribution to a fibrotic process have been reported in experimental settings. Nevertheless, MSCs moved quickly from bench to bedside and over 280 clinical trials are registered, of which 28 focus on the treatment of liver diseases. If no severe side-effects were observed so far, long-term benefits remain uncertain. More preclinical data regarding mechanisms of action, long term safety and efficacy are warranted before initiating large scale clinical application. The proposal of this review is to visit the current state of knowledge regarding mechanisms behind the therapeutic effects of MSCs in the treatment of experimental liver diseases, to address questions about efficacy and risk, and to discuss recent clinical advances involving MSC-based therapies.

A pilot study of autologous CD34-depleted bone marrow mononuclear cell transplantation via the hepatic artery in five patients with liver failure

BACKGROUND AIMS

Many rodent experiments and human studies on stem cell therapy have shown promising therapeutic approaches to liver diseases. We investigated the clinical outcomes of five patients with liver failure of various causes who received autologous CD34-depleted bone marrow-derived mononuclear cell (BM-MNC) transplantation, including mesenchymal stromal cells, through the hepatic artery.

METHODS

CD34-depleted BM-MNCs were obtained from five patients waiting for liver transplantation by bone marrow aspiration and using the CliniMACS CD34 Reagent System (Miltenyi Biotech, Bergisch Gladbach, Germany), and autologous hepatic artery infusion was performed. The causes of hepatic decompensation were hepatitis B virus (HBV), hepatitis C virus (HCV), propylthiouracil-induced toxic hepatitis and Wilson disease.

RESULTS

Serum albumin levels improved 1 week after transplantation from 2.8 g/dL, 2.4 g/dL, 2.7 g/dL and 1.9 g/dL to 3.3 g/dL, 3.1 g/dL, 2.8 g/dL and 2.6 g/dL. Transient liver elastography data showed some change from 65 kPa, 33 kPa, 34.8 kPa and undetectable to 46.4 kPa, 19.8 kPa, 29.1 kPa and 67.8 kPa at 4 weeks after transplantation in a patient with Wilson disease, a patient with HCV, and two patients with HBV. Ascites decreased in two patients. One of the patients with HBV underwent liver transplantation 4 months after the infusion, and the hepatic progenitor markers (cytokeratin [CD]-7, CD-8, CD-9, CD-18, CD-19, c-Kit and epithelial cell adhesion molecule [EpCAM]) were highly expressed in the explanted liver.

CONCLUSIONS

Serum albumin levels, liver stiffness, liver volume, subjective healthiness and quality of life improved in the study patients. Although these findings were observed in a small population, the results may suggest a promising future for autologous CD34-depleted BM-MNC transplantation as a bridge to liver transplantation in patients with liver failure.

The use of cellular technologies in treatment of liver pathologies

Cell techniques find increasing application in modern clinical practice. The II and III phases of clinical trials are already under way for various cellular products used for the restoration of the functions of the cornea, larynx, skin, etc. However, the obtainment of functional cell types specific to different organs and tissues still remains a subject of laboratory research. Liver is one of the most important organs; the problems and prospects of cellular therapy for liver pathologies are currently being actively studied. Cellular therapy of liver pathologies is a complex multistage process requiring a thorough understanding of the molecular mechanisms occurring in liver cells during differentiation and regeneration. An analysis of the current cellular therapy for liver pathologies is presented, the use of various cell types is described, the main molecular mechanisms of hepatocyte differentiation are analyzed, and the challenges and prospects of cell therapy for liver disorders are discussed in this review.

Interplay between bone marrow and liver in the pathogenesis of hepatic fibrosis

Recent advances in the technologies of both molecular biology and regenerative medicine have made it possible to identify bone marrow (BM)-derived cells migrating into various fibrotic organs including the liver. A number of studies have reported that BM-derived cells migrating into fibrotic liver tissue exhibit a myofibroblast-like phenotype and may participate in the progression of liver fibrosis. On the other hand, it has also been shown that BM-derived cells express matrix metalloproteinases and contribute to the regression of experimental liver fibrosis. These contradictory results may arise, at least in part, from the uncertainty of various different methods that have been used in those studies. In this review article, we describe the interplay between BM and liver in the progression and regression of liver fibrosis, with an emphasis on the necessity of qualified methods with high specificity and sensitivity to evaluate the role of BM-derived cells in collagen production.

Liver regenerative medicine: advances and challenges

Liver transplantation is the standard care for many end-stage liver diseases. However, donor organs are scarce and some people succumb to liver failure before a donor is found. Liver regenerative medicine is a special interdisciplinary field of medicine focused on the development of new therapies incorporating stem cells, gene therapy and engineered tissues in order to repair or replace the damaged organ. In this review we consider the emerging progress achieved in the hepatic regenerative medicine within the last decade. The review starts with the characterization of liver organogenesis, fetal and adult stem/progenitor cells. Then, applications of primary hepatocytes, embryonic and adult (mesenchymal, hematopoietic and induced pluripotent) stem cells in cell therapy of liver diseases are considered. Current advances and challenges in producing mature hepatocytes from stem/progenitor cells are discussed. A section about hepatic tissue engineering includes consideration of synthetic and natural biomaterials in engineering scaffolds, strategies and achievements in the development of 3D bioactive matrices and 3D hepatocyte cultures, liver microengineering, generating bioartificial liver and prospects for fabrication of the bioengineered liver.

Stem cell therapy in chronic liver disease

PURPOSE OF REVIEW

To provide an overview of the current status of liver regeneration therapies for liver cirrhosis and future prospects.

RECENT FINDINGS

Various clinical studies for liver disease have been reported, including hepatic administration of autologous CD34-positive cells induced by granulocyte colony-stimulating factor, portal vein administration of CD133-positive mononuclear cells, and administration of autologous bone marrow-derived mesenchymal stem cells. Effectiveness of these approaches has been shown in some patients. We have also reported improved liver fibrosis and function with infusion of autologous bone marrow cells in a basic study with mice, and on the basis of those results started autologous bone marrow cell infusion (ABMi) therapy for liver cirrhosis. The efficacy and safety of ABMi therapy has also been reported by other institutions.

SUMMARY

Results of recent clinical studies strongly suggest that liver function-improving effects can be achieved using infusion of bone marrow (stem) cells for cirrhosis. New treatment methods using less-invasive bone marrow-derived cultured cells need to be developed.

Timeline for development of autologous bone marrow infusion (ABMi) therapy and perspective for future stem cell therapy

Liver cirrhosis patients generally progress to liver failure. To cure this progressive disease, we developed a novel cell therapy using bone marrow cells; autologous bone marrow cell infusion (ABMi) therapy. We previously described the possible action mechanism of ABMi therapy in the cirrhotic liver, and showed the timeline and results of clinical studies of ABMi therapy. We have also carried out other clinical studies using bone marrow cells and granulocyte colony-stimulating factor. Here, we report a new randomized clinical trial to evaluate the effects of ABMi therapy. However, ABMi therapy may not be possible in patients who are unable to undergo general anesthesia; therefore, we have started to develop a next-generation stem cell therapy using cultured mesenchymal stem cells.

Autologous bone marrow stem cells in the treatment of chronic liver disease

Chronic liver disease (CLD) is increasing worldwide yet there has been no major advance in effective therapies for almost five decades. There is mounting evidence that adult haematopoietic stem cells (HSC) are capable of differentiating into many types of tissue, including skeletal and cardiac muscle, neuronal cells, pneumocytes and hepatocytes. These recent advances in regenerative medicine have brought hope for patients with liver cirrhosis awaiting transplantation. New findings in adult stem cell biology are transforming our understanding of tissue repair raising hopes of successful regenerative hepatology. Although all clinical trials to date have shown some improvement in liver function and CD34(+) cells have been used safely for BM transplantation for over 20 years, only randomised controlled clinical trials will be able to fully assess the potential clinical benefit of adult stem cell therapy for patients with CLD. This article focuses on the potential of bone marrow stem cells (BMSCs) in the management of CLD and the unresolved issues regarding their role. We also outline the different mechanisms by which stem cells may impact on liver disease.

Clinical uses of liver stem cells

Liver transplantation offers a definitive cure for many liver and metabolic diseases. However, the complex invasive procedure and paucity of donor liver graft organs limit its clinical applicability. Liver stem cells provide a potentially limitless source of cells that would be useful for a variety of clinical applications. These stem cells or hepatocytes generated from them can be used in cellular transplantation, bioartificial liver devices and drug testing in the development of new drugs. In this chapter, we review the technical aspects of clinical applications of liver stem cells and the progress made to date in the clinical setting. The difficulties and challenges of realizing the potential of these cells are discussed.

Are autologous bone marrow stem cell transplantation and transcatheter arterial embolization the best choices for patients with hepatocellular carcinoma and hepatic dysfunction? Report of a case

The purpose of this work was to evaluate the effects of autologous bone marrow stem cell transplantation (AMSCT) and transarterial embolization (TAE) in patients with hepatocellular carcinoma (HCC) and hepatic dysfunction. A 58-year-old male with HCC and hepatic function of Child's class C was treated with 8 ml of a lipiodol emulsion by injection into the artery feeding of his tumor, and >10(8) bone marrow stem cells were isolated from 400 ml bone marrow and then injected into the right hepatic artery. The patient's laboratory examinations revealed a progressive decrease in total bilirubin (from 264.8 to 77.9 μmol/L) and direct bilirubin (from 222.0 to 59.7 μmol/L) after 1 month, and a repeat CT showed that most of the tumor was filled with lipiodol. The combined treatment using AMSCT and TAE is a good choice of treatment for HCC patients who are unable to tolerate TACE due to hepatic dysfunction.

Coleta e cultura de células-tronco obtidas da polpa de dentes decíduos: técnica e relato de caso clínico

INTRODUÇÃO: as células-tronco (CT) possuem capacidade de induzir a regeneração tecidual e, portanto, apresentam um potencial terapêutico. Assim como a medula óssea e o cordão umbilical, a polpa dentária é uma das fontes disponíveis de CT. O seu fácil acesso e o fato de os dentes decíduos não serem órgãos vitais, que normalmente são descartados após a esfoliação, provêm um atrativo para testes de segurança e viabilidade terapêutica dessas células. OBJETIVOS: descrever a coleta, o isolamento e o cultivo de CT obtidas da polpa de dentes decíduos, assim como a sua caracterização por meio de citometria de fluxo e da indução da diferenciação em linhagens osteogênica e adipogênica. MÉTODOS: as CT foram obtidas de forma relativamente simples e apresentaram boa capacidade proliferativa, mesmo a partir de pouca quantidade de tecido pulpar. RESULTADOS: a análise por citometria de fluxo confirmou as características de CT mesenquimais, com baixos níveis de expressão dos antígenos CD34 e CD45, que são marcadores de células hematopoiéticas, e altos níveis de expressão dos antígenos CD105, CD166, CD90 e CD73, que são marcadores de CT mesenquimais. A plasticidade das células foi confirmada pela identificação de depósitos de cálcio nas culturas que receberam meio osteogênico, e de acúmulo lipídico intracelular nas culturas que receberam meio adipogênico. CONCLUSÕES: as CT de dentes decíduos têm um potencial promissor de aplicação em regeneração tecidual. Sendo assim, é importante difundir entre os cirurgiões-dentistas o conhecimento sobre a existência e as características dessa fonte de CT, discutindo a técnica utilizada, suas limitações e possíveis indicações.

Stem and progenitor cells in liver regeneration and repair

Mammalian liver has a unique capacity to regenerate following resection or injury, and recovery of liver mass is mainly through proliferation of remaining adult hepatocytes. However, in pathologic conditions, especially during acute liver failure (ALF) and advanced stages of chronic liver disease (CLD), regeneration eventually fails and orthothopic liver transplantation (OLT) represents the only curative approach. The clinical scenario of a world-wide increasing incidence of end-stage CLD and an associated lack of organ availability has led several laboratories to explore the feasibility and efficiency of experimental alternatives to OLT involving cellular therapy. This review presents experimental and clinical studies performed in the last 10-15 years where adult and embryonic hepatocytes, hepatic stem/progenitor cells and extrahepatic stem cells have been used as transplantable cell sources.