Improved Liver Function in Patients with Liver Cirrhosis After Autologous Bone Marrow Cell Infusion Therapy

Hepatic arterial infusion of autologous CD34+ cells for hepatitis C virus-related decompensated cirrhosis: A multicenter, open-label, exploratory randomized controlled trial

Introduction

In this multicenter clinical study, we aimed to investigate the efficacy and safety of the transhepatic arterial administration of granulocyte-colony stimulating factor (G-CSF)-mobilized autologous peripheral blood (PB)-CD34+ cells compared with standard therapy in patients with decompensated cirrhosis type C.

Methods

Patients were randomly assigned (2:1) to the CD34+ cell transplant (CD34+ cell) or standard-of-care (SOC) group and followed up for 52 weeks. The primary endpoints were the non-progression rate of Child-Pugh (CP) scores at 24 weeks post-enrollment and the safety of the protocol treatment.

Results

Fourteen patients (CD34+ cell group: 10; SOC group: 4) were enrolled. CP scores at 24 weeks had a non-progression rate of 90% in the CD34+ cell group and 100% in the SOC group, with no significant difference between groups. Importantly, 4 out of 10 patients in the CD34+ cell group exhibited an improvement from decompensated to compensated cirrhosis, whereas all patients in the SOC group remained in decompensated cirrhosis. With regard to secondary endpoints, a trend toward increased serum albumin levels in the CD34+ cell group was noted. Serious adverse events (SAEs) occurred in three patients in the CD34+ cell group and in one patient in the SOC group. No causal relationship was observed between all SAEs and G-CSF, leukapheresis, or cell transplantation in the CD34+ cell group. No patients died and no hepatocellular carcinoma occurred within the study period.

Conclusions

PB-CD34+ cell infusion therapy may have the potential to circumvent the decompensated stage of cirrhosis, thus avoiding the need for liver transplantation.

Application of a laparoscopic device for cell-derived sheet transplantation on the liver in a porcine model

BACKGROUND

Cell-derived sheets are of global interest for regenerative therapy. Transplanting a sheet for abdominal organs requires a device for laparoscopic delivery to minimize invasiveness. Here, using a porcine model, we aimed to confirm the feasibility of a device developed to deliver sheets to the thoracic cavity in a laparoscopic transplantation procedure.

MATERIAL AND METHODS

We used the device to transplant human skeletal myoblast cell sheets onto the liver and measured extra-corporeal, intra-abdominal, and total procedure times for sheet transplantation. Tissues, including the liver and the sheet, were collected two days after transplantation and analyzed histologically.

RESULTS

In all experiments (n = 27), all sheets were successfully placed at target locations. The mean (± standard deviation) extra-corporeal, intra-abdominal, and total procedure times were 44 ± 29, 33 ± 12, and 77 ± 36 s, respectively. We found no difference between the two surgeons in procedure times. Histological analyses showed no liver damage with the transplantation and that sheets were transplanted closely onto the liver tissue without gaps.

CONCLUSION

We confirmed the feasibility of a simple universal device to transplant cell-derived sheets via laparoscopic surgery. This device could support a minimally invasive procedure for sheet transplantation.

A first-in-human clinical study of laparoscopic autologous myoblast sheet transplantation to prevent delayed perforation after duodenal endoscopic mucosal dissection

BACKGROUND

The detection rate of superficial non-ampullary duodenal epithelial tumors (SNADETs) has recently been increasing. Large tumors may contain malignant lesions and early therapeutic intervention is recommended. Endoscopic mucosal dissection (ESD) is considered a feasible treatment modality, however, the anatomical and physiological characteristics of the duodenum create a risk of postoperative perforation after ESD.

METHODS

To explore whether myoblast sheet transplantation could prevent delayed perforation after ESD, a first-in-human (FIH) clinical trial of laparoscopic autologous myoblast sheet transplantation after duodenal ESD was launched. Autologous myoblast sheets fabricated from muscle tissue obtained seven weeks before ESD were transplanted laparoscopically onto the serous side of the ESD. The primary endpoints were the onset of peritonitis due to delayed perforation within three days after surgery and all adverse events during the follow-up period.

RESULTS

Three patients with SNADETs ≥ 20 mm in size underwent transplantation of a myoblast sheet onto the serous side of the duodenum after ESD. In case 1, The patient's postoperative course was uneventful. Endoscopy and abdominal computed tomography revealed no signs of delayed perforation. Despite incomplete mucosal closure in case 2, and multiple micro perforations during ESD in case 3, cell sheet transplantation could prevent the postoperative massive perforation after ESD, and endoscopy on day 49 after transplantation revealed no stenosis.

CONCLUSIONS

This clinical trial showed the safety, efficacy, and procedural operability of this novel regenerative medicine approach involving transplanting an autologous myoblast sheet laparoscopically onto the serosa after ESD in cases with a high risk of delayed perforation. This result indicates the potential application of cell sheet medicine in treating various abdominal organs and conditions with minimal invasiveness in the future.

TRIAL REGISTRATION

jRCT, jRCT2073210094. Registered November 8 2021, https://jrct.niph.go.jp/latest-detail/jRCT2073210094 .

Manipulating HGF signaling reshapes the cirrhotic liver niche and fills a therapeutic gap in regeneration mediated by transplanted stem cells

Long-term stem cell survival in the cirrhotic liver niche to maintain therapeutic efficacy has not been achieved. In a well-defined diethylnitrosamine (DEN)-induced liver fibrosis/cirrhosis animal model, we previously showed that liver-resident stem/progenitor cells (MLpvNG2+ cells) or immune cells have improved survival in the fibrotic liver environment but died via apoptosis in the cirrhotic liver environment, and increased levels of hepatocyte growth factor (HGF) mediated this cell death. We tested the hypothesis that inhibiting HGF signaling during the cirrhotic phase could keep the cells alive. We used adeno-associated virus (AAV) vectors designed to silence the c-Met (HGF-only receptor) gene or a neutralizing antibody (anti-cMet-Ab) to block the c-Met protein in the DEN-induced liver cirrhosis mouse model transplanted with MLpvNG2+ cells between weeks 6 and 7 after DEN administration, which is the junction of liver fibrosis and cirrhosis at the site where most intrahepatic stem cells move toward apoptosis. After 4 weeks of treatment, the transplanted MLpvNG2+ cells survived better in c-Met-deficient mice than in wild-type mice, and cell activity was similar to that of the mice that received MLpvNG2+ cells at 5 weeks after DEN administration (liver fibrosis phase when most of these cells proliferated). Mechanistically, a lack of c-Met signaling remodeled the cirrhotic environment, which favored transplanted MLpvNG2+ cell expansion to differentiation into mature hepatocytes and initiate endogenous regeneration by promoting mature host hepatocyte generation and mediating functional improvements. Therapeutically, c-Met-mediated regeneration can be mimicked by anti-cMet-Ab to interfere functions, which is a potential drug for cell-based treatment of liver fibrosis/cirrhosis.

Do cord blood CD34 cells stay the same or change after expansion: A comprehensive analysis of gene expression results before and after seven days of cell culture

INTRODUCTION

Hematopoietic stem cell transplantation is used to treat hematopoietic malignancies and bone marrow failure syndromes. Due to the difficulties of using these cells isolated from the bone marrow, an additional source for receiving essential hematopoietic cells is umbilical cord blood. But the main problem with using the umbilical cord is its insufficient blood volume. The ex-vivo reproductive system of hematopoietic stem cells can overcome this problem that has the ability for Transplantation and hematopoiesis in the long term. This study aimed to evaluate the expression profile of CD133 + umbilical cord blood microRNAs in different stages of hematopoietic stem cells before and after ex-vivo proliferation.

MATERIALS AND METHODS

The expression profile of 1034 types of microRNA of CD34 + hematopoietic stem cells of the umbilical cord was analyzed before and after ex vivo proliferation. After isolating CD34 + cells from the umbilical cord blood of normal-born babies using MACS (Magnetic-activated cell sorting) column, these cells were cultured in a Stem span culture medium containing SCF, FLT3, and TPO cytokines in 24-well plates. The expression profile of microRNAs was investigated on days 0 and 7 days after cultivation by the Real-Time PCR method.

RESULTS

The results showed that the production of two-thirds of the micro-RNAs was reduced during the proliferation process. The micro-RNA expression of hematopoietic stem cell proliferation was also lower. At the same time, micro-RNA expression related to differentiation was higher.

CONCLUSION

The observed reduction in miRNA expression may be attributed to enhanced differentiation through proliferation. Therefore, miRNAs appear to be a viable option for regulating the proliferation processes of Hematopoietic stem cell transplantation.

Enhancing mesenchymal stem cell survival and homing capability to improve cell engraftment efficacy for liver diseases

Although mesenchymal stem cell (MSC) transplantation provides an alternative strategy for end-stage liver disease (ESLD), further widespread application of MSC therapy is limited owing to low cell engraftment efficiency. Improving cell engraftment efficiency plays a critical role in enhancing MSC therapy for liver diseases. In this review, we summarize the current status and challenges of MSC transplantation for ESLD. We also outline the complicated cell-homing process and highlight how low cell engraftment efficiency is closely related to huge differences in extracellular conditions involved in MSC homing journeys ranging from constant, controlled conditions in vitro to variable and challenging conditions in vivo. Improving cell survival and homing capabilities enhances MSC engraftment efficacy. Therefore, we summarize the current strategies, including hypoxic priming, drug pretreatment, gene modification, and cytokine pretreatment, as well as splenectomy and local irradiation, used to improve MSC survival and homing capability, and enhance cell engraftment and therapeutic efficiency of MSC therapy. We hope that this review will provide new insights into enhancing the efficiency of MSC engraftment in liver diseases.

Granulocyte colony-stimulating factor with or without stem or progenitor cell or growth factors infusion for people with compensated or decompensated advanced chronic liver disease

BACKGROUND

Advanced chronic liver disease is characterised by a long compensated phase followed by a rapidly progressive 'decompensated' phase, which is marked by the development of complications of portal hypertension and liver dysfunction. Advanced chronic liver disease is considered responsible for more than one million deaths annually worldwide. No treatment is available to specifically target fibrosis and cirrhosis; liver transplantation remains the only curative option. Researchers are investigating strategies to restore liver functionality to avoid or slow progression towards end-stage liver disease. Cytokine mobilisation of stem cells from the bone marrow to the liver could improve liver function. Granulocyte colony-stimulating factor (G-CSF) is a 175-amino-acid protein currently available for mobilisation of haematopoietic stem cells from the bone marrow. Multiple courses of G-CSF, with or without stem or progenitor cell or growth factors (erythropoietin or growth hormone) infusion, might be associated with accelerated hepatic regeneration, improved liver function, and survival.

OBJECTIVES

To evaluate the benefits and harms of G-CSF with or without stem or progenitor cell or growth factors (erythropoietin or growth hormone) infusion, compared with no intervention or placebo in people with compensated or decompensated advanced chronic liver disease.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, three other databases, and two trial registers (October 2022) together with reference-checking and web-searching to identify additional studies. We applied no restrictions on language and document type.

SELECTION CRITERIA

We only included randomised clinical trials comparing G-CSF, independent of the schedule of administration, as a single treatment or combined with stem or progenitor cell infusion, or with other medical co-interventions, with no intervention or placebo, in adults with chronic compensated or decompensated advanced chronic liver disease or acute-on-chronic liver failure. We included trials irrespective of publication type, publication status, outcomes reported, or language.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane procedures. All-cause mortality, serious adverse events, and health-related quality of life were our primary outcomes, and liver disease-related morbidity, non-serious adverse events, and no improvement of liver function scores were our secondary outcomes. We undertook meta-analyses, based on intention-to-treat, and presented results using risk ratios (RR) for dichotomous outcomes and the mean difference (MD) for continuous outcomes, with 95% confidence intervals (CI) and I2 statistic values as a marker of heterogeneity. We assessed all outcomes at maximum follow-up. We determined the certainty of evidence using GRADE, evaluated the risk of small-study effects in regression analyses, and conducted subgroup and sensitivity analyses.

MAIN RESULTS

We included 20 trials (1419 participants; sample size ranged from 28 to 259), which lasted between 11 and 57 months. Nineteen trials included only participants with decompensated cirrhosis; in one trial, 30% had compensated cirrhosis. The included trials were conducted in Asia (15), Europe (four), and the USA (one). Not all trials provided data for our outcomes. All trials reported data allowing intention-to-treat analyses. The experimental intervention consisted of G-CSF alone or G-CSF plus any of the following: growth hormone, erythropoietin, N-acetyl cysteine, infusion of CD133-positive haemopoietic stem cells, or infusion of autologous bone marrow mononuclear cells. The control group consisted of no intervention in 15 trials and placebo (normal saline) in five trials. Standard medical therapy (antivirals, alcohol abstinence, nutrition, diuretics, β-blockers, selective intestinal decontamination, pentoxifylline, prednisolone, and other supportive measures depending on the clinical status and requirement) was administered equally to the trial groups. Very low-certainty evidence suggested a decrease in mortality with G-CSF, administered alone or in combination with any of the above, versus placebo (RR 0.53, 95% CI 0.38 to 0.72; I2 = 75%; 1419 participants; 20 trials). Very low-certainty evidence suggested no difference in serious adverse events (G-CSF alone or in combination versus placebo: RR 1.03, 95% CI 0.66 to 1.61; I2 = 66%; 315 participants; three trials). Eight trials, with 518 participants, reported no serious adverse events. Two trials, with 165 participants, used two components of the quality of life score for assessment, with ranges from 0 to 100, where higher scores indicate better quality of life, with a mean increase from baseline of the physical component summary of 20.7 (95% CI 17.4 to 24.0; very low-certainty evidence) and a mean increase from baseline of the mental component summary of 27.8 (95% CI 12.3 to 43.3; very low-certainty evidence). G-CSF, alone or in combination, suggested a beneficial effect on the proportion of participants who developed one or more liver disease-related complications (RR 0.40, 95% CI 0.17 to 0.92; I2 = 62%; 195 participants; four trials; very low-certainty evidence). When we analysed the occurrences of single complications, there was no suggestion of a difference between G-CSF, alone or in combination, versus control, in participants in need of liver transplantation (RR 0.85, 95% CI 0.39 to 1.85; 692 participants; five trials), in the development of hepatorenal syndrome (RR 0.65, 95% CI 0.33 to 1.30; 520 participants; six trials), in the occurrence of variceal bleeding (RR 0.68, 95% CI 0.37 to 1.23; 614 participants; eight trials), and in the development of encephalopathy (RR 0.56, 95% CI 0.31 to 1.01; 605 participants; seven trials) (very low-certainty evidence). The same comparison suggested that G-CSF reduces the development of infections (including sepsis) (RR 0.50, 95% CI 0.29 to 0.84; 583 participants; eight trials) and does not improve liver function scores (RR 0.67, 95% CI 0.53 to 0.86; 319 participants; two trials) (very low-certainty evidence).

AUTHORS' CONCLUSIONS

G-CSF, alone or in combination, seems to decrease mortality in people with decompensated advanced chronic liver disease of whatever aetiology and with or without acute-on-chronic liver failure, but the certainty of evidence is very low because of high risk of bias, inconsistency, and imprecision. The results of trials conducted in Asia and Europe were discrepant; this could not be explained by differences in participant selection, intervention, and outcome measurement. Data on serious adverse events and health-related quality of life were few and inconsistently reported. The evidence is also very uncertain regarding the occurrence of one or more liver disease-related complications. We lack high-quality, global randomised clinical trials assessing the effect of G-CSF on clinically relevant outcomes.

Optimizing the Seeding Density of Human Mononuclear Cells to Improve the Purity of Highly Proliferative Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) hold considerable promise for regenerative medicine. Optimization of the seeding density of mononuclear cells (MNCs) improves the proliferative and differentiation potential of isolated MSCs. However, the underlying mechanism is unclear. We cultured human bone marrow MNCs at various seeding densities (4.0 × 10⁴, 1.25 × 10⁵, 2.5 × 10⁵, 6.0 × 10⁵, 1.25 × 10⁶ cells/cm²) and examined MSC colony formation. At lower seeding densities (4.0 × 10⁴, 1.25 × 10⁵ cells/cm²), colonies varied in diameter and density, from dense to sparse. In these colonies, the proportion of highly proliferative MSCs increased over time. In contrast, lower proliferative MSCs enlarged more rapidly. Senescent cells were removed using a short detachment treatment. We found that these mechanisms increase the purity of highly proliferative MSCs. Thereafter, we compared MSCs isolated under optimized conditions with a higher density (1.25 × 10⁶ cells/cm²). MSCs under optimized conditions exhibited significantly higher proliferative and differentiation potential into adipocytes and chondrocytes, except for osteocytes. We propose the following conditions to improve MSC quality: (1) optimizing MNC seeding density to form single-cell colonies; (2) adjusting incubation times to increase highly proliferative MSCs; and (3) establishing a detachment processing time that excludes senescent cells.

Therapeutic Perspectives for the Clinical Application of Umbilical Cord Hematopoietic and Mesenchymal Stem Cells: Overcoming Complications Arising After Allogeneic Hematopoietic Stem Cell Transplantation

This review focuses on the therapeutic features of umbilical cord blood (UCB) cells as a source for allogeneic hematopoietic stem cell transplantation (aHSCT) in adult and child populations to treat malignant and nonmalignant hematologic diseases, genetic disorders, or pathologies of the immune system, when standard treatment (e.g., chemotherapy) is not effective or clinically contraindicated. In this article, we summarize the immunological properties and the advantages and disadvantages of using UCB stem cells and discuss a variety of treatment outcomes using different sources of stem cells from different donors both in adults and pediatric population. We also highlight the critical properties (total nucleated cell dose depending on HLA compatibility) of UCB cells that reach better survival rates, reveal the advantages of double versus single cord blood unit transplantation, and present recommendations from the most recent studies. Moreover, we summarize the mechanism of action and potential benefit of mesenchymal umbilical cord cells and indicate the most common posttransplantation complications.

The Long Telling Story of "Endothelial Progenitor Cells": Where Are We at Now?

Endothelial progenitor cells (EPCs): The name embodies years of research and clinical expectations, but where are we now? Do these cells really represent the El Dorado of regenerative medicine? Here, past and recent literature about this eclectic, still unknown and therefore fascinating cell population will be discussed. This review will take the reader through a temporal journey that, from the first discovery, will pass through years of research devoted to attempts at their definition and understanding their biology in health and disease, ending with the most recent evidence about their pathobiological role in cardiovascular disease and their recent applications in regenerative medicine.

The regenerative effect of stem cells on acetaminophen-induced hepatotoxicity in male albino rats

Background

Acetaminophen overdose is the leading cause of acute liver injury (ALI) and acute liver failure (ALF) in the developed world. We aimed at studying the therapeutic potential of bone marrow mesenchymal stem cells (MSCs) in accelerating healing of acetaminophen-induced hepatotoxicity.

Results

This prospective study included 50 male albino rats divided into 2 groups: hepatotoxic group and non-hepatotoxic group. Hepatotoxicity was induced in experimental rats by acetaminophen and then stem cells were transplanted into the rats and their effects on the liver cells were assessed. After injection of BM MSCs, the cells reached the targeted tissues. They were established in the central veins and blood sinusoids in the liver tissue. The hepatotoxic liver showed degeneration and loss of normal hepatic architecture as well as necrotic areas and congestion mainly in the portal tract vessels, dilation of blood sinusoids, and infiltration by inflammatory cells around the central veins. In addition, there were abnormal nuclei either irregular in shape or showing loss of open face compared to the normal control group. The liver tissue in BM MSC-treated group showed restoration of normal architecture of the liver tissue.

Conclusion

Administration of MSCs has hepato-therapeutic effect on acetaminophen-induced hepatotoxicity in rats. The mechanism of this hepatoprotective effect may be through anti-inflammatory, anti-apoptotic, and immunomodulatory actions of MSCs.

Clinical Trials of Stem Cell Therapy in Japan: The Decade of Progress under the National Program

Stem cell therapy is a current world-wide topic in medical science. Various therapies have been approved based on their effectiveness and put into practical use. In Japan, research and development-related stem cell therapy, generally referred to as regenerative medicine, has been led by the government. The national scheme started in 2002, and support for the transition to clinical trials has been accelerating since 2011. Of the initial 18 projects that were accepted in the budget for preclinical research, 15 projects have begun clinical trials so far. These include the transplantation of retinal, cardiac, and dopamine-producing cells differentiated from human induced pluripotent stem (iPS) cells and hepatocyte-like cells differentiated from human embryonic stem (ES) cells. The distinctive feature of the stem cell research in Japan is the use of iPS cells. A national framework was also been set-up to attain the final goal: health insurance coverage. Now, insurance covers cell transplantation therapies for the repair and recovery of damaged skin, articular cartilage, and stroke as well as therapies introduced from abroad, such as allogeneic mesenchymal stem cells for graft-versus-host disease and chimeric antigen receptor-T (CAR-T) cell therapy. To prepare this review, original information was sought from Japanese authentic websites, which are reliable but a little hard to access due to the fact of multiple less-organized databases and the language barrier. Then, each fact was corroborated by citing its English version or publication in international journals as much as possible. This review provides a summary of progress over the past decade under the national program and a state-of-the-art factual view of research activities, government policy, and regulation in Japan for the realization of stem cell therapy.

Psoas Major Skeletal Muscle Mass Is a Predictive Factor for Independent Walking After Living Donor Liver Transplantation

BACKGROUND

Mobility affects the ability of patients to live independently post-discharge. This study aimed to identify factors affecting the achievement of independent walking in patients after living donor liver transplantation (LDLT).

METHODS

This retrospective cohort study involved 40 patients who had undergone LDLT for severe hepatic dysfunction (Child-Pugh class C) in the Department of Transplant Surgery of our hospital between January 2010 and October 2019 and received physiotherapy during hospital admission. To identify factors associated with independent walking, we classified patients based on their ability to walk independently. We performed multiple logistic regression analyses with the patients' attributes, biochemical tests, and physical function, considering the achievement or non-achievement of independent walking as dependent variables, and factors that were significantly different between the 2 groups in the univariate analysis (P < .05) as independent variables, after adjusting for age, sex, and body mass index. Moreover, we calculated cutoff values from the receiver operating characteristic (ROC) curves.

RESULTS

All patients suffered from severe hepatic dysfunction (Child-Pugh class C). The mobility Functional Independence Measure score following rehabilitation was positively correlated with the psoas major muscle index within 1 month after LDLT and at the beginning of physiotherapy. The only factor associated with achieving independent walking at the end of physiotherapy (on discharge) was the psoas major muscle index within 1 month of LDLT (odds ratio = 35.03, P < .05), and its cutoff value, calculated from the ROC curves curve, was 4.46.

CONCLUSION

Psoas major skeletal muscle mass is a reliable index for independent walking after LDLT.

Bone marrow mesenchymal stem cells inhibit hepatic fibrosis via the AABR07028795.2/rno-miR-667-5p axis

Background

The mechanism of bone marrow mesenchymal stem cells (BMSCs) in treating hepatic fibrosis remains unclear.

Methods

TGF-β1-induced hepatic stellate cell (HSC)-T6 and CCl4-induced hepatic fibrosis rats were treated with BMSCs. HSC-T6 cell activity was determined using the cell counting kit-8 assay, and the histology change was evaluated using hematoxylin and eosin and Masson staining. The expression of fibrosis markers was determined using real-time quantitative PCR, Western blotting, and immunocytochemistry. RNA sequencing (RNA-seq) was used to screen the lncRNAs involved in the effect of BMSCs in fibrosis, and the function of fibrosis-associated lncRNA in fibrosis histology change and fibrosis marker expression was investigated. The potential miRNA target of lncRNA was predicted using R software. The interaction between lncRNA and miRNA was verified using luciferase report system and RNA immunoprecipitation (RIP) in 293T and HSC-T6 cells.

Results

BMSC attenuated TGF-β1-induced HSC-T6 activation and suppressed the expression of fibrosis-associated gene (MMP2, Collagen I, and αSMA) expression at the transcription and translation levels. BMSC treatment also improves hepatic fibrosis in rats with CCl4-induced fibrosis by decreasing the expression of fibrosis-associated genes and suppressing collagen deposition in the liver. RNA-seq revealed that AABR07028795.2 (lnc-BIHAA1) was downregulated in the TGF-β1-induced HSC-T6 after treatment with BMSCs as compared with those in TGF-β1-induced HSC-T6, and subsequently, functional analysis showed that lnc-BIHAA1 plays a beneficial role in suppressing hepatic fibrosis. Luciferase activity assay and RIP revealed that lnc-BIHAA1 interacted with the miRNA, rno-miR-667-5p, functioning as a fibrosis phenotype suppressor in TGF-β1-induced HSC-T6. Moreover, overexpression of rno-miR-667-5p significantly reverses the effect of lnc-BIHAA1 on HSC-T6.

Conclusions

BMSC treatment suppresses hepatic fibrosis by downregulating the lnc-BIHAA1/rno-miR-667-5p signaling pathway in HSCs. Our results provide a scientific basis for establishing BMSCs as a biological treatment method for liver fibrosis.

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.

Structural and Temporal Dynamics of Mesenchymal Stem Cells in Liver Diseases From 2001 to 2021: A Bibliometric Analysis

Background

Mesenchymal stem cells (MSCs) have important research value and broad application prospects in liver diseases. This study aims to comprehensively review the cooperation and influence of countries, institutions, authors, and journals in the field of MSCs in liver diseases from the perspective of bibliometrics, evaluate the clustering evolution of knowledge structure, and discover hot trends and emerging topics.

Methods

The articles and reviews related to MSCs in liver diseases were retrieved from the Web of Science Core Collection using Topic Search. A bibliometric study was performed using CiteSpace and VOSviewer.

Results

A total of 3404 articles and reviews were included over the period 2001-2021. The number of articles regarding MSCs in liver diseases showed an increasing trend. These publications mainly come from 3251 institutions in 113 countries led by China and the USA. Li L published the most papers among the publications, while Pittenger MF had the most co-citations. Analysis of the most productive journals shows that most are specialized in medical research, experimental medicine and cell biology, and cell & tissue engineering. The macroscopical sketch and micro-representation of the whole knowledge field are realized through co-citation analysis. Liver scaffold, MSC therapy, extracellular vesicle, and others are current and developing areas of the study. The keywords "machine perfusion", "liver transplantation", and "microRNAs" also may be the focus of new trends and future research.

Conclusions

In this study, bibliometrics and visual methods were used to review the research of MSCs in liver diseases comprehensively. This paper will help scholars better understand the dynamic evolution of the application of MSCs in liver diseases and point out the direction for future research.

Highly feasible procedure for laparoscopic transplantation of cell sheets under pneumoperitoneum in porcine model

INTRODUCTION

Cell sheet technology is one of the most successful methodologies in regenerative medicine. Various applications of cell sheets have been introduced in first-in-human studies in several clinical fields. When transplanting a cell sheet into internal organs, a relatively large incision is required for delivery due to difficulty handling the sheet. We developed a laparoscopic delivery procedure for safe and easy transplantation of cell sheets in a porcine model.

METHODS

Pneumoperitoneum was established by inflation with CO₂. First, to increase the strength during handling, fibrin was sprayed onto the surface of the cell sheet, and then a myoblast sheet was placed onto the newly developed carrier. The sheets were pinched with laparoscopic forceps to insert into the abdominal cavity through the laparoscopic port. Myoblast sheets were then applied to the surface of the liver, colon, small intestine, and stomach, and procedure times were measured. At three days post transplantation, a histopathological examination was performed to confirm engraftment of the sheet. The function and engraftment were also analyzed in a duodenal endoscopic submucosal dissection (ESD) model.

RESULTS

The fibrin-processed myoblast sheet was able to be managed with conventional laparoscopic forceps without breaking. Despite the drastic change in air pressure by passing through the laparoscopic port, the sheets suffered no apparent damage. The transplantation procedure times did not markedly differ among transplant sites. A histopathological examination revealed thin-layered, desmin-positive cells at each transplant site. With transplantation following ESD, the engrafted myoblast sheets effectively prevented delayed perforation.

CONCLUSIONS

Our procedure is simple, and the system involves a carrier made of medically fit silicon, commercially available fibrin glue and conventional laparoscopic forceps. Our procedure is a powerful tool for laparoscopical cell sheet transplantation.

Using adipose-derived mesenchymal stem cells to fight the metabolic complications of obesity: Where do we stand?

Obesity is a critical risk factor for the development of metabolic diseases, and its prevalence is increasing worldwide. Stem cell-based therapies have become a promising tool for therapeutic intervention. Among them are adipose-derived mesenchymal stem cells (ADMSCs), secreting numerous bioactive molecules, like growth factors, cytokines, and chemokines. Their unique features, including immunosuppressive and immunomodulatory properties, make them an ideal candidates for clinical applications. Numerous experimental studies have shown that ADMSCs can improve pancreatic islet cell viability and function, ameliorate hyperglycemia, improve insulin sensitivity, restore liver function, counteract dyslipidemia, lower pro-inflammatory cytokines, and reduce oxidative stress in the animal models. These results prompted scientists to use ADMSCs clinically. However, up to date, there have been few clinical studies or ongoing trails using ADMSCs to treat metabolic disorders such as type 2 diabetes mellitus (T2DM) or liver cirrhosis. Most human studies have implemented autologous ADMSCs with minimal risk of cellular rejection. Because the functionality of ADMSCs is significantly reduced in subjects with obesity and/or metabolic syndrome, their efficacy is questioned. ADMSCs transplantation may offer a potential therapeutic approach for the treatment of metabolic complications of obesity, but randomized controlled trials are required to establish their safety and efficacy in humans prior to routine clinical use.

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.

Hepatic Regeneration in Cirrhosis

End-stage liver disease is characterized by massive hepatocyte death resulting in clinical decompensation and organ failures. Clinical consequences in cirrhosis are the results of the loss of functional hepatocytes and excessive scarring. The only curative therapy in advanced cirrhosis is orthotropic liver transplantation, but the clinical demand outweighs the availability of acceptable donor organs. Moreover, this also necessitates lifelong immunosuppression and carries associated risks. The liver has a huge capability for regeneration. Self-replication of quiescent differentiated hepatocytes and cholangiocytes occurs in patients with acute liver injury. Due to limited hepatocyte self-renewal capacity in advanced cirrhosis, great interest has therefore been shown in characterizing the possible role of hepatic progenitor cells and bone marrow-derived stem cells to therapeutically aid this process. Transplantation of cells from various sources that can be properly differentiated into functional liver cells or use of growth factors for ex-vivo expansion of progenitor cells is needed at utmost priority. Multiple researches over the last two decades have aided researchers in refining proliferation, differentiation, and storage techniques and understand the functionality of these cells for use in clinical practice. However, these cell-based therapies are still experimental and have to be used in trial settings.

Mesenchymal stem cell therapy in decompensated liver cirrhosis: a long-term follow-up analysis of the randomized controlled clinical trial

BACKGROUND

Mesenchymal stem cell (MSC) infusion was reported to improve liver function in patients with decompensated liver cirrhosis (DLC); however, whether the medication can improve outcome of these patients is poorly understood.

METHODS

This prospective, open-labeled, randomized controlled study enrolled 219 patients with HBV-related DLC who were divided into control group (n = 111) and umbilical cord-derived MSC (UC-MSC)-treated group (n = 108), then all of them received a follow-up check from October 2010 to October 2017. The treated patients received three times of UC-MSC infusions at 4-week intervals plus conventional treatment that was only used for control group. The overall survival rate and HCC-free survival rate were calculated as primary endpoints and the liver function and adverse events associated with the medication were also evaluated.

RESULTS

During the follow-up check period from 13 to 75th months, there was a significantly higher overall survival rate in the treated group than the control group, while the difference of the hepatocellular carcinoma event-free survival rate between the treated and control groups was not observed during the 75-month follow-up. UC-MSC treatment markedly improved liver function, as indicated by the levels of serum albumin, prothrombin activity, cholinesterase, and total bilirubin during 48 weeks of follow-up. No significant side effects or treatment-related complications were observed in the UC-MSC group.

CONCLUSIONS

Therapy of UC-MSC is not only well tolerated, but also significantly improves long-term survival rate, as well as the liver function in patients with HBV-related DLC. UC-MSC medication, therefore, might present a novel therapeutic approach for the disease.

Granulocyte colony stimulating factor: A potential therapeutic rescue in severe alcoholic hepatitis and decompensated cirrhosis

Liver cirrhosis accounts for over 2 million deaths annually worldwide. A subset of these patients - those with alcoholic hepatitis and decompensated cirrhosis, have abysmal short-term survival. Liver transplant is the only intervention of proven survival benefit; however organ availability is a major limitation. It is thus imperative to assess potential benefit of experimental therapies as a bridge to transplant. Stem cell therapies have shown some promise in patients with end-stage liver disease. Of these, bone-marrow derived hematopoietic stem cells have generated the most interest. Animal as well as human data suggest biological plausibility of stem cell translocation from bone marrow to liver, giving credence to cytokine therapies based on bone marrow stimulation. Granulocyte colony stimulating factor has been the most frequently used cytokine for this purpose. This intervention has shown encouraging results in terms of safety as well as survival benefits in small clinical trials. The evidence, however, is sparse and heterogeneous. In this review we describe the biological plausibility, mechanisms of action, and clinical evidence of the use of cytokine based stem cell therapy in patients with end-stage liver disease.

Transition of clinical and basic studies on liver cirrhosis treatment using cells to seek the best treatment

The liver is a highly regenerative organ; however, its regeneration potential is reduced by chronic inflammation with fibrosis accumulation, leading to cirrhosis. With an aim to tackle liver cirrhosis, a life-threatening disease, trials of autologous bone marrow cell infusion (ABMi) therapy started in 2003. Clinical studies revealed that ABMi attenuated liver fibrosis and improved liver function in some patients; however, this therapy has some limitations such as the need of general anesthesia. Following ABMi therapy, studies have focused on specific cells such as mesenchymal stromal cells (MSCs) from a variety of tissues such as bone marrow, adipose tissue, and umbilical cord tissues. Particularly, studies have focused on gaining mechanistic insights into MSC distribution and effects on immune cells, especially macrophages. Several basic studies have reported the use of MSCs for liver cirrhosis models, while a number of clinical studies have used autologous and allogeneic MSCs; however, there are only a few reports on the obvious substantial effect of MSCs in clinical studies. Since then, studies have analyzed and identified the important signals or components in MSCs that regulate immune cells, such as macrophages, under cirrhotic conditions and have revealed that MSC-derived exosomes are key regulators. Researchers are still seeking the best approach and filling the gap between basic and clinical studies to treat liver cirrhosis. This paper highlights the timeline of basic and clinical studies analyzing ABMi and MSC therapies for cirrhosis and the scope for future studies and therapy.

Application of Stem Cell Therapy during the treatment of HIV/AIDS and Duchenne Muscular Dystrophy

Treating diseases such as Muscular dystrophy (MD) and HIV/AIDS poses several challenges to the rapidly evolving field of regenerative medicine. Previously, stem cell therapy has been said to affect the clinical courses of HIV/AIDS and MD, but, in practice, eradication or control of these diseases was not achievable. The introduction of gene editing into stem cell therapy has stimulated HIV/AIDS and MD cell therapy research studies substantially. Here, we review current methods of treating HIV/AIDS and MD using stem cell therapy. This review also details the use of different types of cells and methods in cell therapy and the modeling of new cell-based therapies to treat Duchenne muscular dystrophy. We speculate that the effective use stem cell therapy in conjunction with other treatment therapies such as steroids and rehabilitation could improve livelihood.

Modulation of macrophage phenotype to treat liver fibrosis-Current approaches and future possibilities

Liver fibrosis is a leading cause of death worldwide, accounting for approximately 2 million deaths annually. Despite its wide prevalence, there are currently no pharmacological therapies that directly reverse the fibrotic process in patients. Studies over the last decade have revealed that liver fibrosis is reversible in patients and in animal models. Further, studies aimed at elucidating the mechanism of fibrosis reversal have revealed that macrophages are central to this process. During resolution of fibrosis, proinflammatory macrophages shift phenotype to pro-resolution macrophages which produce matrix degrading enzymes and mediators that inactivate hepatic stellate cells, the cell type principally involved in matrix production during fibrosis development. Since fibrosis reversal begins when disease-causing macrophages transition to disease-reversing macrophages, studies have focused on identifying pharmacological agents that stimulate this process to occur. If successful, these "drugs" would constitute a first-in-class, macrophage-targeted therapeutic approach to reverse liver fibrosis. In the following review, we summarize the current approaches under investigation to modify macrophage phenotype for liver disease treatment. Further we discuss the potential of other approaches to identify novel macrophage-targeted drugs that modify the phenotype of these cells.

Mesenchymal stem cell therapy for liver disease: current status and future perspectives

PURPOSE OF REVIEW

Liver transplantation is the gold standard for the treatment of end-stage liver disease. However, a shortage of donor organs, high cost, and surgical complications limit the use of this treatment. Cellular therapies using hepatocytes, hematopoietic stem cells, bone marrow mononuclear cells, and mesenchymal stem cells (MSCs) are being investigated as alternative treatments to liver transplantation. The purpose of this review is to describe studies using MSC transplantation for liver diseases based on the reported literature and to discuss prospective research designed to improve the efficacy of MSC therapy.

RECENT FINDINGS

MSCs have several properties that show potential to regenerate injured tissues or organs, such as homing, transdifferentiation, immunosuppression, and cellular protective capacity. Additionally, MSCs can be noninvasively isolated from various tissues and expanded ex vivo in sufficient numbers for clinical evaluation.

SUMMARY

Currently, there is no approved MSC therapy for the treatment of liver disease. However, MSC therapy is considered a promising alternative treatment for end-stage liver diseases and is reported to improve liver function safely with no side effects. Further robust preclinical and clinical studies will be needed to improve the therapeutic efficacy of MSC transplantation.

C-Kit, a Double-Edged Sword in Liver Regeneration and Diseases

Previous studies have reported an important role of c-kit in embryogenesis and adulthood. Activation of the SCF/KIT signal transduction pathway is customarily linked to cell proliferation, migration and survival thus influence hematopoiesis, pigmentation, and spermatogenesis. The role of c-kit in the liver is controversial, it is however argued that it is a double-edged sword in liver regeneration and diseases. First, liver c-kit⁺ cells, including oval cells, bile epithelial cells, and part of hepatocytes, participate in liver tissue repair by regenerating target cells according to the type of liver injury. At the same time, c-kit⁺ mast cells, act as immature progenitors in circulation, playing a critical role in liver fibrosis. Furthermore, c-kit is also a proto-oncogene. Notably, c-kit overexpression regulates gastrointestinal stromal tumors. Various studies have explored on c-kit and hepatocellular carcinoma, nevertheless, the intricate roles of c-kit in the liver are largely understudied. Herein, we extensively summarize previous studies geared toward providing hints for future clinical and basic research.

Can bone marrow-derived mesenchymal stem cells change liver volume?: A case report

Several studies have described the effectiveness of mesenchymal stem cell (MSC) transplantation in patients with liver cirrhosis (LC). However, in the majority, biochemical tests, clinical features, and pathologic results were used rather than radiologic tests to compare treatment outcomes. A 57‐year‐old male visited a stem cell clinic with a diagnosis of LC attributed to hepatitis B virus. This patient took tenofovir and diuretics at the initial presentation and was administered bone marrow‐derived MSCs twice via hepatic intra‐arterial infusion. Subsequently, the patient's clinical symptoms and biochemical tests (aspartate aminotransferase, alanine aminotransferase, albumin, total bilirubin, international normalized ratio, creatinine, alpha‐fetoprotein) improved. Computed tomography findings showed loss of ascites, reduced nodularity, and especially increased liver volume, which suggested that MSCs have meaningful effects on liver volume, as well as improving liver function.

Trans-portal hepatic infusion of cultured bone marrow-derived mesenchymal stem cells in a steatohepatitis murine model

The incidence of nonalcoholic steatohepatitis-related liver cirrhosis is increasing. We used a steatohepatitis murine model fed a choline-deficient, l-amino acid-defined (CDAA) diet with a single injection of carbon tetrachloride (CCl₄) to evaluate the efficacy of trans-portal hepatic infusion of bone marrow-derived mesenchymal stem cells (BMSCs) for liver fibrosis, liver steatosis, and oxidative stress. Mice were fed a CDAA diet and injected with a single intraperitoneal dose of CCl₄ (0.5 ml/kg) after 4 weeks of CDAA diet. After 12 weeks of CDAA diet, 1 × 10⁶ luciferase-positive syngeneic BMSCs (Luc-BMSCs) were infused into the animal spleen. An in vivo imaging system was used to confirm Luc-BMSC accumulation in the liver via the portal vein, and at 4 weeks after infusion, we compared liver fibrosis, liver steatosis, and oxidative stress. After the BMSC-infusion, serum albumin and serum total bilirubin were significantly improved. Liver fibrosis assessed by Sirius red staining, α-smooth muscle actin protein, and collagen 1A1 mRNA expression was significantly suppressed. Furthermore, liver steatosis area was significantly lower, the 8-hydroxy-2'-deoxyguanosine-positive cells were significantly fewer, and superoxide dismutase 2 protein expression of the liver was significantly increased. In conclusion, our data confirmed the efficacy of trans-portal hepatic infusion of BMSCs in a steatohepatitis murine model.

The development of mesenchymal stem cell therapy in the present, and the perspective of cell-free therapy in the future

Cirrhosis is a chronic condition that can lead to liver failure. Currently, the viable option for decreasing mortality is liver transplantation. However, transplant surgery is highly invasive. Therefore, cell-based therapy has been developed as an alternative. Based on promising findings from preclinical research, some new trials have been registered. One of them was autologous bone marrow cell infusion therapy and found that ameliorating liver fibrosis activated liver regeneration. Now, majority of trials focus on low-immunogenicity mesenchymal stem cells (MSCs) appropriate for allogeneic administration. However, despite about 20 years of research, only a limited number of cell-based therapies have entered routine practice. Furthermore, potential shortcomings of cell-based therapy include a limit on the number of cells, which may be administered, as well as their failure to infiltrate target organs. On the other hand, these research show that MSCs act as "conducting cells" and regulate host cells including macrophages via extracellular vesicles (EVs) or exosome signals, leading to ameliorate liver fibrosis and promote regeneration. Therefore, the concept of cell-free therapy, which makes use of cell-derived EVs or exosomes, is attracting attention. Cell-free therapies may be safely administered in large doses and are able to infiltrate target organs. However, development of cell-free therapy exhibits its own set of challenges and such therapy may not be completely curative in the context of liver disease. This review describes the history of cell-based therapy research and recent advances in cell-free therapy, as well as discussing the need for more effective therapies.

Body mass index changes after transjugular intrahepatic portosystemic shunt in individuals with cirrhosis

OBJECTIVES

Liver cirrhosis is often accompanied by portal hypertension and malnutrition, two common complications that seriously affect treatment efficacy and quality of life. This study aimed to investigate the effect of transjugular intrahepatic portosystemic shunt (TIPS) on body mass index (BMI) and metabolism in individuals with cirrhotic portal hypertension, and the risk factors that affect changes of BMI.

METHODS

A retrospective study was performed to collect basic information before and after TIPS. This study included 77 participants. For each participant, we assayed body nutrition parameters: change of weight and BMI, routine liver and kidney function tests, and free fatty acids. In addition, we evaluated glucose and biochemical indexes. We used analysis of variance and regression analysis to investigate the effect of TIPS on BMI and metabolism in individuals with cirrhotic portal hypertension, and the risk factors that affect changes of BMI and metabolic components.

RESULTS

After TIPS, there was significant improvement in weight, BMI, red blood cell count, blood platelet count, hemoglobin, and Child-Pugh score in individuals with cirrhotic portal hypertension. Average weight and BMI increased after TIPS by 3.2% and 3.4%, respectively (P < 0.05). After 36 months, there were no significant differences in weight and BMI between before and after TIPS. We also observed a dose-response association of pre-TIPS blood ammonia and increased post-TIPS BMI (P = 0.05) in men.

CONCLUSIONS

This study suggests that individuals with cirrhosis treated with TIPS may see improvement in overall clinical and physical status, as measured by increased weight and BMI. Our data also indicate that pre-TIPS blood ammonia is positively associated with post-TIPS BMI.

Advantages of adipose tissue stem cells over CD34+ mobilization to decrease hepatic fibrosis in Wistar rats

INTRODUCTION AND OBJECTIVES

Chronic liver inflammation may lead to hepatic cirrhosis, limiting its regenerative capacity. The clinical standard of care is transplantation, although stem cell therapy may be an alternative option. The study aim was to induce endogenous hematopoietic stem cells (HSCs) with granulocyte colony stimulating factor (G-CSF) and/or intravenous administration of adipose tissue-derived mesenchymal stem cells (MSCs) to decrease hepatic fibrosis in an experimental model.

MATERIAL AND METHODS

A liver fibrosis model was developed with female Wistar rats via multiple intraperitoneal doses of carbon tetrachloride. Three rats were selected to confirm cirrhosis, and the rest were set into experimental groups to evaluate single and combined therapies of G-CSF-stimulated HSC mobilization and intravenous MSC administration.

RESULTS

Treatment with MSCs and G-CSF significantly improved alanine amino transferase levels, while treatment with G-CSF, MSCs, and G-CSF+MSCs decreased aspartate amino transferase levels. Hepatocyte growth factor (HGF) and interleukin 10 levels increased with MSC treatment. Transforming growth factor β levels were lower with MSC treatment. Interleukin 1β and tumor necrosis factor alpha levels decreased in all treated groups. Histopathology showed that MSCs and G-CSF reduced liver fibrosis from F4 to F2.

CONCLUSIONS

MSC treatment improves liver function, decreases hepatic fibrosis, and plays an anti-inflammatory role; it promotes HGF levels and increased proliferating cell nuclear antigen when followed by MSC treatment mobilization using G-CSF. When these therapies were combined, however, fibrosis improvement was less evident.

Progress in Liver Transplant Tolerance and Tolerance-Inducing Cellular Therapies

Liver transplantation is currently the most effective method for treating end-stage liver disease. However, recipients still need long-term immunosuppressive drug treatment to control allogeneic immune rejection, which may cause various complications and affect the long-term survival of the recipient. Many liver transplant researchers constantly pursue the induction of immune tolerance in liver transplant recipients, immunosuppression withdrawal, and the maintenance of good and stable graft function. Although allogeneic liver transplantation is more tolerated than transplantation of other solid organs, and it shows a certain incidence of spontaneous tolerance, there is still great risk for general recipients. With the gradual progress in our understanding of immune regulatory mechanisms, a variety of immune regulatory cells have been discovered, and good results have been obtained in rodent and non-human primate transplant models. As immune cell therapies can induce long-term stable tolerance, they provide a good prospect for the induction of tolerance in clinical liver transplantation. At present, many transplant centers have carried out tolerance-inducing clinical trials in liver transplant recipients, and some have achieved gratifying results. This article will review the current status of liver transplant tolerance and the research progress of different cellular immunotherapies to induce this tolerance, which can provide more support for future clinical applications.

Recent advances of sterile inflammation and inter-organ cross-talk in alcoholic liver disease

Alcoholic liver disease (ALD) is one of the fastest-growing concerns worldwide. In addition to bacterial endotoxins in the portal circulation, recent lines of evidence have suggested that sterile inflammation caused by a wide range of stimuli induces alcoholic liver injury, in which damage-associated molecular patterns (DAMPs) play critical roles in inducing de novo lipogenesis and inflammation through the activation of cellular pattern recognition receptors such as Toll-like receptors in non-parenchymal cells. Interestingly, alcohol-mediated metabolic, neurological, and immune stresses stimulate the generation of DAMPs that are released not only in the liver, but also in other organs, such as adipose tissue, intestine, and bone marrow. Thus, diverse DAMPs, including retinoic acids, proteins, lipids, microRNAs, mitochondrial DNA, and mitochondrial double-stranded RNA, contribute to a broad spectrum of ALD through the production of multiple pro-inflammatory cytokines, chemokines, and ligands in non-parenchymal cells, such as Kupffer cells, hepatic stellate cells, and various immune cells. Therefore, this review summarizes recent studies on the identification and understanding of DAMPs, their receptors, and cross-talk between the liver and other organs, and highlights successful therapeutic targets and potential strategies in drug development that can be used to combat ALD.

Clinical application of stem cell in patients with end-stage liver disease: progress and challenges

End-stage liver disease (ESLD) is life-threatening disease worldwide, and patients with ESLD should be referred to liver transplantation (LT). However, the use of LT is limited by the lacking liver source, high cost and organ rejection. Thus, other alternative options have been explored. Stem cell therapy may be a potential alternative for ESLD treatment. With the potential of self-renewal and differentiation, both hepatic and extrahepatic stem cells have attracted a lot of attention. Among them, multipotent stem cells are most widely studies owing to their characteristics. Multipotent stem cells mainly consist of two subpopulations: hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs). Accumulating evidences have proved that either bone marrow (BM)-derived HSCs mobilized by granulocyte colony-stimulating factor or MSCs transplantation can improve the biochemical indicators of patients with ESLD. However, there are some challenges to be resolved before stem cells widely used in clinic, including the best stem cell source, the optimal route for stem cells transplantation, and the dose and frequency of stem cell injected. The purpose of this review is to discuss the potential of stem cell in liver diseases, particularly, the clinical progress and challenges of multipotent stem cells in the field of ESLD.

The clinical application of mesenchymal stem cells in liver disease: the current situation and potential future

Liver disease is a major health issue which present poor clinical treatment performance. Cirrhosis and liver failure are common clinical manifestations of liver diseases. Liver transplantation is recognized as the ultimate and most efficient therapy to the end stage of liver disease. But it was limited by the shortage of honor organs and high cost. Nowadays, stem cell therapy gained more and more attention due to its attractive efficacy in treating liver disease especially in cirrhosis during the clinical trials. Mesenchymal stem cell (MSC) can be differentiated into hepatocytes, promote liver regeneration, inhibit liver fibrosis and induce liver apoptosis, particularly via paracrine mechanisms. This review will highlight recent clinical applications of MSC, providing the available evidence and discussing some unsolved questions in treating liver disease.

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.

Bone marrow-derived humoral factors suppress oxidative phosphorylation, upregulate TSG-6, and improve therapeutic effects on liver injury of mesenchymal stem cells

Mesenchymal stem cells, which have the potential to be used in regenerative medicine, require improvements in quality for patient use. To maintain stemness of cultured bone marrow-derived mesenchymal stem cells, we focused on the bone marrow microenvironment, generated a conditioned medium of whole bone marrow cells (BMC-CM), and assessed its effects on bone marrow-derived mesenchymal stem cells. BMC-CM suppressed morphological deterioration and proliferative decline in cultured bone marrow-derived mesenchymal stem cells, suppressed mitochondrial oxidative phosphorylation activity, a stemness indicator, and upregulated suppressors of oxidative phosphorylation such as hypoxia-inducible factor-1 alpha, Sirtuin 3, 4, and 5. Furthermore, BMC-CM upregulated TNF-stimulated gene 6 and ameliorated the therapeutic effects of cells on liver injury in carbon tetrachloride-administered rats. Since the elimination of 20-220-nm particles attenuated the effects of BMC-CM, we further analyzed exosomal microRNAs produced by whole bone marrow cells. Among the 49 microRNAs observed to be upregulated during the preparation of BMC-CM, several were identified that were associated with suppression of oxidative phosphorylation, upregulation of TNF-stimulated gene 6, and the pathogenesis of liver diseases. Thus, bone marrow-derived humoral factors including exosomal microRNAs may help to improve the therapeutic quality of bone marrow-derived mesenchymal stem cells for liver regenerative therapy.

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

Objective

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

Methods

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

Results

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

Conclusion

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

AT-MSCs Antifibrotic Activity is Improved by Eugenol through Modulation of TGF-β/Smad Signaling Pathway in Rats

For hepatic failure, stem cell transplantation has been chosen as an alternative therapy, especially for mesenchymal stem cells (MSCs). The aim of this study was to investigate the effect of eugenol (EUG) on the in vivo antifibrotic activity of adipose tissue-derived MSCs (AT-MSCs) and the underlying mechanism. After characterization of MSCs, rats were divided into five groups, Group 1 (normal control), Group 2 (CCl₄), Group 3 (CCl₄ + AT-MSCs), Group 4 (CCl₄ + EUG) and Group 5 (CCl₄ + AT-MSCs + EUG). Biochemical and histopathological investigations were performed. Furthermore, expression of type 1 collagen, α-SMA, TGF-β1, Smad3 and P-Smad3 was estimated. Compared to the single treatment with AT-MSCs, the combination treatment of the fibrotic rats with AT-MSCs and EUG significantly improved the plasma fibrinogen concentration, IL-10 level and proliferating cell nuclear antigen expression, and also significantly decreased the serum levels of liver enzymes, IL-6, IL-1β, TNF-α, type III collagen, hyaluronic acid, hydroxyproline and the TGF-β growth factor. Furthermore, the combination treatment significantly decreased the hepatic expression of fibrotic markers genes (Type 1 collagen and α-SMA) and proteins (α-SMA, TGF-β1 and phospho-Smad3) more than the treatment with AT-MSCs alone. We demonstrated that the combination treatment with EUG and AT-MSCs strongly inhibited the advancement of CCl₄-induced hepatic fibrosis, compared with AT-MSCs alone, through TGF-β/Smad pathway inhibition. This approach is completely novel, so more investigations are necessary to improve our perception of the underlying molecular mechanisms accountable for the effects of EUG on the antifibrotic potential of AT-MSCs.

Effects of Extracellular Vesicles Derived from Mesenchymal Stem/Stromal Cells on Liver Diseases

Therapeutic effects of Mesenchymal Stem/Stromal Cells (MSCs) transplantation have been observed in various disease models. However, it is thought that MSCs-mediated effects largely depend on the paracrine manner of secreting cytokines, growth factors, and Extracellular Vesicles (EVs). Similarly, MSCs-derived EVs also showed therapeutic benefits in various liver diseases through alleviating fibrosis, improving regeneration of hepatocytes, and regulating immune activity. This review provides an overview of the MSCs, their EVs, and their therapeutic potential in treating various liver diseases including liver fibrosis, acute and chronic liver injury, and Hepatocellular Carcinoma (HCC). More specifically, the mechanisms by which MSC-EVs induce therapeutic benefits in liver diseases will be covered. In addition, comparisons between MSCs and their EVs were also evaluated as regenerative medicine against liver diseases. While the mechanisms of action and clinical efficacy must continue to be evaluated and verified, MSCs-derived EVs currently show tremendous potential and promise as a regenerative medicine treatment for liver disease in the future.

Effect of Autologous Bone Marrow Stem Cell Therapy in Patients with Liver Cirrhosis: A Meta-analysis

Background and Aims: Although autologous bone marrow stem cell (BMSC) transplantation is an effective treatment for liver cirrhosis, there are few reports describing the optimal delivery route and number of injected BMSCs. Methods: A literature search was conducted using PubMed, ISI Web of Science, Cochrane Central Register of Controlled Trials, and EBSCO. A meta-analysis was performed to assess the effect of BMSCs on liver and coagulation function indices. Subgroup analysis was performed based on number of injected BMSCs, delivery route, and length of follow-up. Results: A total of 15 studies were selected from among 1903 potential studies for analysis. Autologous BMSC transplantation significantly improved aspartate aminotransferase, total bilirubin, albumin, prothrombin time, prothrombin activity, prothrombin concentration, Child-Pugh score, and model for end-stage liver disease. In the subgroup analysis of cell numbers, all four of the indices were significantly improved when the number of BMSCs was >4 × 10⁸. The subgroup analysis referring to the delivery route showed that arterial infusion increased the therapeutic effect over venous infusion. Finally, in the subgroup analysis of follow-up length, the results showed that BMSC therapy significantly improved liver function at 2 weeks after transplantation. In addition, this therapy improved coagulation 4 weeks after the transplant, with a maintenance of efficacy for up to 24 weeks. Conclusions: Autologous BMSC therapy is beneficial for liver improvement and coagulation in patients with liver cirrhosis. The therapeutic effect was generated at 2-4 weeks after transplantation. The effect lasted for 24 weeks but no more than 48 weeks. The greatest benefit to patients was observed with a 4 × 10⁸ autologous BMSC transplant via the hepatic artery.

Mesenchymal stem cell therapies for liver cirrhosis: MSCs as "conducting cells" for improvement of liver fibrosis and regeneration

Mesenchymal stem cells (MSCs) can be cultured relatively easily and can be obtained not only from the bone marrow, but also from medical waste such as adipose tissue and umbilical cord tissue. Because of its low antigenicity, allogeneic MSC injection is safe. MSCs have been evaluated in more than 900 clinical trials in a variety of fields, with more than 50 clinical trials related to liver diseases. Experiments have suggested that MSCs function as "conducting cells" to affect various "effective cells" such as T cells, B cells, and macrophages. Recent clinical trials have focused on allogeneic MSCs. Thus, studies are needed to determine the most effective cell source, culture conditions, cell numbers, administration frequency, administration route, cost, safety, and liver disease treatments. Recently, the functions of exosomes have gained attention, and cell-free therapy may become possible as an alternative therapy for liver disease. In this review, we introduce general information, mechanism, representative clinical study data, recently started or planned clinical trials, and possibility of cell-free therapy of MSCs.

Autologous Bone Marrow Stem Cell Transplantation in Liver Cirrhosis after Correcting Nutritional Anomalies, A Controlled Clinical Study

Objective

Liver transplantation is the gold standard approach for decompensated liver cirrhosis. In recent years, stem cell therapy has raised hopes that adjusting some clinical and laboratory parameters could lead to successful treatments for this disease. Cirrhotic patients may have multiple systemic abnormalities in peripheral blood and irregular cell populations in bone marrow (BM). Correcting these abnormalities before BM aspiration may improve the effectiveness of cell-based therapy of liver cirrhosis.

Materials and Methods

In this controlled clinical trial study, 20 patients with decompensated liver cirrhosis were enrolled. Patients were randomly assigned to control and experimental groups. Blood samples were obtained to measure vitamin B12, folate, serum iron, total iron bonding capacity (TIBC) and ferritin before any intervention. Furthermore, the iron storage and fibrosis level in BM biopsies, as well as the percentage of different cell populations, were evaluated. Prior to cell isolation for transplantation, we performed palliative supplement therapy followed by a correction of nutritional deficiencies. Mononuclear cells (MNCs) were then isolated from BM aspirates and transfused through peripheral vein in patients in the experimental group. The model of end-stage liver disease (MELD) score, The international normalized ratio (INR), serum albumin and bilirubin levels were assessed at 0 (baseline), 3 and 6 months after cell transplantation.

Results

The MELD score (P=0.0001), INR (P=0.012), bilirubin (P<0.0001) and total albumin (P<0.0001) levels improved significantly in the experimental group after cell transplantation compared to the baseline and control groups. Moreover, the increase in serum albumin levels of patients in the experimental group was statistically significant 6 months after transplantation.

Conclusion

We have successfully improved the conditions of preparing -BM-derived stem cells for transplantation. Although these cells are relatively safe and have been shown to improve some clinical signs and symptoms temporarily, there need to be more basic studies regarding the preparation steps for effective clinical use (Registration number: IRCT2014091919217N1).

Epimedin C Protects H2O2-Induced Peroxidation Injury by Enhancing the Function of Endothelial Progenitor HUVEC Populations

Endothelial cell injury and apoptosis induced by oxidative stress serve important roles in many vascular diseases. The repair of endothelial cell vascular injury relies on the function of local endothelial progenitor cells (EPCs). Our previous study indicated that epimedin C, a major flavonoid derived from Herba epimedii (yin yang huo), could promote vascularization by inducing endothelial-like differentiation of mesenchymal stem cells C3H/10T1/2 both in vivo and in vitro. In view of the significant cardiovascular protective effects of Herba epimedii, we detected a protective effect of epimedin C on hydrogen peroxide (H₂O₂)-induced peroxidation injury in human umbilical vein endothelial cells (HUVECs) and the role of EPC in this process. The results show that epimedin C increased the expression of the stem cell marker, CD34 and PROM1, and subsequently enhanced the expression and function of vascular endothelial growth factor and matrix metalloproteinase (MMP)-2 in local vascular endothelial cells. In conclusion, epimedin C protects H₂O₂-induced peroxidation injury by enhancing the function of endothelial progenitor HUVEC populations.

Wound healing and fibrosis: current stem cell therapies

Scarring is a result of the wound healing response and causes tissue dysfunction after injury. This process is readily evident in the skin, but also occurs internally across organ systems in the form of fibrosis. Stem cells are crucial to the innate tissue healing response and, as such, present a possible modality to therapeutically promote regenerative healing while minimizing scaring. In this review, the cellular basis of scaring and fibrosis is examined. Current stem cell therapies under exploration for skin wound healing and internal organ fibrosis are discussed. While most therapeutic approaches rely on the direct application of progenitor-type cells to injured tissue to promote healing, novel strategies to manipulate the scarring response are also presented. As our understanding of developmental and stem cell biology continues to increase, therapies to encourage regeneration of healthy functional tissue after damage secondary to injury or disease will continue to expand.

Evaluation of the Effects of Cultured Bone Marrow Mesenchymal Stem Cell Infusion on Hepatocarcinogenesis in Hepatocarcinogenic Mice With Liver Cirrhosis

OBJECTIVES

Liver transplantation remains the only curative therapy for decompensated liver cirrhosis. However, it has several limitations, and not all patients can receive liver transplants. Therefore, liver regenerative therapy without liver transplantation is considered necessary. In this study, we attempted minimally invasive liver regenerative therapy by peripheral vein infusion of bone marrow-derived mesenchymal stem cells (BMSCs) cultured from a small amount of autologous bone marrow fluid and evaluated the effects of BMSCs on hepatocarcinogenesis in a mouse model.

METHODS

C57BL/6 male mice were injected intraperitoneally with N-nitrosodiethylamine once at 2 weeks of age, followed by carbon tetrachloride twice a week from 6 weeks of age onwards, to create a mouse model of highly oncogenic liver cirrhosis. From 10 weeks of age, mouse isogenic green fluorescent protein-positive BMSCs (1.0 × 10⁶/body weight) were infused once every 2 weeks, for a total of 5 times, and the effects of frequent BMSC infusion on hepatocarcinogenesis were evaluated.

RESULTS

In the histologic evaluation, no significant differences were observed between the controls and BMSC-administered mice in terms of incidence rate, number, or average size of foci and tumors. However, significant suppression of fibrosis and liver injury was confirmed in the group that received BMSC infusions.

DISCUSSION

Considering that BMSC infusion did not promote carcinogenesis, even in the state of highly oncogenic liver cirrhosis, autologous BMSC infusion might be a safe and effective therapy for human decompensated liver cirrhosis.

Hepatic microcirculation and mechanisms of portal hypertension

The liver microcirculatory milieu, mainly composed of liver sinusoidal endothelial cells (LSECs), hepatic stellate cells (HSCs) and hepatic macrophages, has an essential role in liver homeostasis, including in preserving hepatocyte function, regulating the vascular tone and controlling inflammation. Liver microcirculatory dysfunction is one of the key mechanisms that promotes the progression of chronic liver disease (also termed cirrhosis) and the development of its major clinical complication, portal hypertension. In the present Review, we describe the current knowledge of liver microcirculatory dysfunction in cirrhotic portal hypertension and appraise the preclinical models used to study the liver circulation. We also provide a comprehensive summary of the promising therapeutic options to target the liver microvasculature in cirrhosis.