Human mesenchymal stem cell transfusion is safe and improves liver function in acute-on-chronic liver failure patients

Efficacy and safety of mesenchymal stem cell therapy in acute on chronic liver failure: a systematic review and meta-analysis of randomized controlled clinical trials

BACKGROUND

Acute-on-chronic liver failure has become a serious global health burden, which is characterized by an acute deterioration of liver function, rapidly evolving organ failure, and high short-term mortality in patients with chronic liver disease. The pathogenesis includes extensive hepatic necrosis, which is related to intense systemic inflammation and subsequently causes the inflammatory cytokine storm, resulting in portal hypertension, organ dysfunction, and organ failure. Mesenchymal stem cells can function as seed cells to remodel and repair damaged liver tissues, thus showing potential therapeutic alternatives for patients with chronic liver disease. However, standard treatment protocols for mesenchymal stem cells in acute-on-chronic liver failure patients have not been established.

METHODS

We conducted a detailed search from PubMed/Medline, Web of Science, EMBASE, and Cochrane Library to find randomized controlled trials published before October 23, 2021. We formulated criteria for the literature screening according to the PICOS principle (Population, Intervention, Comparison, Outcome, Study design). Subsequently, the bias risk assessment tool was used to assess the quality of all enrolled studies. Finally, outcome measurements including the model of end-stage liver disease score, albumin, total bilirubin, coagulation function, and aminotransferase were extracted for statistical analysis.

RESULTS

A total of 7 clinical trials were included. The results of enrolled studies indicated that patients with acute-on-chronic liver failure who received mesenchymal stem cells inoculation showed a decreased MELD score in 4 weeks and 24 weeks, compared with counterparts who received conventional treatment. Reciprocally, mesenchymal stem cells inoculation improved the ALB levels in 4 weeks and 24 weeks. For secondary indicators, mesenchymal stem cells treatment significantly reduced INR levels and ALT levels, compared with the control group. Our results showed no significant differences in the incidence of adverse reactions or serious adverse events monitored in patients after mesenchymal stem cells inoculation.

CONCLUSION

This meta-analysis indicated that mesenchymal stem cell infusion is effective and safe in the treatment of patients with acute-on-chronic liver failure. Without increasing the incidence of adverse events or serious adverse events, MSC treatment improved liver function including a decrease in MELD score and an increase in ALB levels in patients with acute-on-chronic liver failure. However, large-cohort randomized controlled trials with longer follow-up periods are required to further confirm our conclusions.

Adipose derived mesenchymal stem cell-seeded regenerated silk fibroin scaffolds reverse liver fibrosis in mice

Liver fibrosis (LF) is an important process in the progression of chronic liver disease to cirrhosis. We have previously demonstrated that a regenerated silk fibroin scaffold loaded with adipose-derived stem cells (RSF + ADSCs) can repair acute liver injury. In this study, we established a chronic LF animal model using carbon tetrachloride (CCl4) and a high-fat diet. We then investigated the liver repair capacity after transplanting RSF + ADSC scaffolds and RSF scaffolds onto the liver surface of mice. Compared with the control group, the concentrations of ALT and AST in the serum were significantly reduced in the RSF and RSF + ADSC groups. HE staining and Masson trichrome staining revealed a decrease in the SAF score in both the RSF and RSF + ADSC groups. Meanwhile, the biomarkers of blood vessels and bile ducts, such as CD34, ERG, muc1, and CK19, were significantly elevated in the RSF + ADSC group. Finally, transcriptome analysis showed that the PPAR signaling pathway, which inhibits liver fibrosis, was significantly upregulated in both the RSF and RSF + ADSC groups. Our study suggests that, compared with RSF scaffolds alone, RSF + ADSCs have a significant repair effect on chronic LF in mice.

Mechanisms of immunity in acutely decompensated cirrhosis and acute-on-chronic liver failure

The identification of systemic inflammation (SI) as a central player in the orchestration of acute-on-chronic liver failure (ACLF) has opened new avenues for the understanding of the pathophysiological mechanisms underlying this disease condition. ACLF, which develops in patients with acute decompensation of cirrhosis, is characterized by single or multiple organ failure and high risk of short-term (28-day) mortality. Its poor outcome is closely associated with the severity of the systemic inflammatory response. In this review, we describe the key features of SI in patients with acutely decompensated cirrhosis and ACLF, including the presence of a high blood white cell count and increased levels of inflammatory mediators in systemic circulation. We also discuss the main triggers (i.e. pathogen- and damage-associated molecular patterns), the cell effectors (i.e. neutrophils, monocytes and lymphocytes), the humoral mediators (acute phase proteins, cytokines, chemokines, growth factors and bioactive lipid mediators) and the factors that influence the systemic inflammatory response that drive organ failure and mortality in ACLF. The role of immunological exhaustion and/or immunoparalysis in the context of exacerbated inflammatory responses that predispose ACLF patients to secondary infections and re-escalation of end-organ dysfunction and mortality are also reviewed. Finally, several new potential immunogenic therapeutic targets are debated.

Hotspots and trends in stem cell therapy for liver fibrosis and cirrhosis: A bibliometric analysis

BACKGROUND

Liver fibrosis and cirrhosis are global medical challenges that require safe and effective treatments. In the past two decades, there has been a surge in research on stem cell therapy for liver fibrosis and cirrhosis. This study aimed to conduct a comprehensive analysis of the research hotspots and trends in this field through bibliometrics.

AIM

To conduct a bibliometric analysis on hotspots and trends in stem cell therapy for treatment of liver fibrosis and cirrhosis.

METHODS

Publications on stem cell therapy for liver fibrosis and cirrhosis were retrieved from the Web of Science Core Collection database. The distribution and collaboration among literature, authors, countries, and institutions were analyzed visually using Excel, CiteSpace, Bibliometrix R-package, VOSviewer and Pajek software. Additionally, an investigation of keywords, burst keywords, and clusters was conducted.

RESULTS

As of September 20, 2024, a total of 1935 documents were retrieved dating from 2004 to 2024, with 1186 strongly relevant publications obtained after screening. China, the United States, and Japan were the major contributors in this field. Cairo University, Zhejiang University and Yamaguchi University were the major institution in this field. The journal Stem Cell Research & Therapy published the most papers. There were 686 authors, with Shuji Terai, Isao Sakaida, Soon Koo Baik, and Lanjuan Li publishing the most papers. The research focused on alcoholic cirrhosis and nonalcoholic fatty liver disease. The emerging areas of interest were extracellular vesicles, exosomes, and their enriched microRNAs. The field is experiencing rapid growth due to the changing research trends and increasing literature.

CONCLUSION

These findings provide a thorough overview of stem cell therapy in the field of liver fibrosis and cirrhosis.

Characterization and Proteomic Profiling of Hepatocyte-like Cells Derived from Human Wharton's Jelly Mesenchymal Stromal Cells: De Novo Expression of Liver-Specific Enzymes

End-stage liver disease (ESLD), affecting millions worldwide, represents a challenging issue for clinical research and global public health. Liver transplantation is the gold standard therapeutic approach but shows some drawbacks. Hepatocyte transplantation could be a reliable alternative for patient treatment. Mesenchymal stromal cells derived from Wharton's jelly of the umbilical cord (WJ-MSCs) can differentiate into hepatocyte-like cells (HLCs) and show immunomodulatory functions. Due to the increasing demand for fully characterized cell therapy vehicles warranting both the safety and efficacy of treatments, in this work, we extensively characterized WJ-MSCs before and after the application of a hepatocyte-directed differentiation protocol. HLCs exhibited a morphology resembling that of hepatocytes, expressed early and late hepatic markers (α-fetoprotein, albumin, CK18, HNF4-α), and acquired hepatic functions (glycogen synthesis, xenobiotics detoxification), as also revealed by the shotgun proteomics approach. HLCs maintained the same pattern of immunomodulatory molecule expression and mesenchymal markers, other than displaying specific enzymes, suggesting these cells as promising candidates for cellular therapy of ESLD. Our work shed new light on the basic biology of HLCs, suggesting new therapeutic approaches to treat ESLD.

Mesenchymal stem cell therapy as a game-changer in liver diseases: review of current clinical trials

Chronic liver diseases, including cirrhosis and liver failure, remain formidable challenges due to their complex progression and limited therapeutic options. Mesenchymal stem cell (MSC) therapy has emerged as a game-changing approach, leveraging its potent immunomodulatory, anti-fibrotic, and regenerative capabilities, along with the ability to transdifferentiate into hepatocytes. This review delves into the latest advances in MSC-based treatments for chronic and end-stage liver diseases, as highlighted in current clinical trials. MSCs derived from bone marrow and umbilical cord have shown remarkable promise in reversing liver damage, improving liver function, and providing hope for patients who do not respond to conventional therapies. When administered through hepatic, portal, or peripheral veins, MSCs have significantly improved liver histology, reduced fibrosis, and restored functional capacity. Furthermore, MSC-derived materials, such as extracellular vesicles and exosomes, are emerging as cutting-edge tools for treating liver failure and mitigating post-transplant complications. While autologous MSC-derived hepatocytes hold promise for non-fatal cirrhosis, allogeneic MSCs are being applied in more severe conditions, including liver failure and transplantation cases. Despite these promising early outcomes, larger trials and long-term studies are essential to fully harness MSCs as a transformative, off-the-shelf alternative to liver transplantation, heralding a new era in regenerative liver therapies.

Human Liver MSCs Retain Their Basic Cellular Properties in Chronically Inflamed Liver Tissue

Every 25th death worldwide is associated with liver pathology. The development of novel approaches to liver diseases therapy and protocols for maintaining the vital functions of patients on the liver transplant waiting list are urgently needed. Resident mesenchymal stem cells (MSCs) play a significant role in supporting liver tissue integrity and improve the liver condition after infusion. However, it remains unclear whether MSCs isolated from chronically inflamed livers are similar in their basic cellular properties to MSCs obtained from healthy livers. We applied a large array of tests to compare resident MSCs isolated from apparently normal liver tissue and from chronically inflamed livers of patients with fibrosis, cirrhosis, and viral hepatitis. Chronic inflammatory environment did not alter the major cellular characteristics of MSCs, including the expression of MSC markers, stem cell markers, adhesion molecules, and the hallmarks of senescence, as well as cell proliferation, migration, and secretome. Only the expression of some immune checkpoints and toll-like receptors was different. Evidently, MSCs with unchanged cellular properties are present in human liver even at late stages of inflammatory diseases. These cells can be isolated and used as starting material in the development of cell therapies of liver diseases.

Cell therapy for end-stage liver disease: Current state and clinical challenge

ABSTRACT

Liver disease involves a complex interplay of pathological processes, including inflammation, hepatocyte necrosis, and fibrosis. End-stage liver disease (ESLD), such as liver failure and decompensated cirrhosis, has a high mortality rate, and liver transplantation is the only effective treatment. However, to overcome problems such as the shortage of donor livers and complications related to immunosuppression, there is an urgent need for new treatment strategies that need to be developed for patients with ESLD. For instance, hepatocytes derived from donor livers or stem cells can be engrafted and multiplied in the liver, substituting the host hepatocytes and rebuilding the liver parenchyma. Stem cell therapy, especially mesenchymal stem cell therapy, has been widely proved to restore liver function and alleviate liver injury in patients with severe liver disease, which has contributed to the clinical application of cell therapy. In this review, we discussed the types of cells used to treat ESLD and their therapeutic mechanisms. We also summarized the progress of clinical trials around the world and provided a perspective on cell therapy.

Mechanism of mesenchymal stem cells in liver regeneration: Insights and future directions

Mesenchymal stem cells (MSCs) are a prevalent source for stem cell therapy and play a crucial role in modulating both innate and adaptive immune responses. Non-alcoholic fatty liver disease (NAFLD) is characterized by the accumulation of triglycerides in liver cells and involves immune system activation, leading to histological changes, tissue damage, and clinical symptoms. A recent publication by Jiang et al, highlighted the potential of MSCs to mitigate in NAFLD progression by targeting various molecular pathways, including glycolipid metabolism, inflammation, oxidative stress, endoplasmic reticulum stress, and fibrosis. In this editorial, we comment on their research and discuss the efficacy of MSC therapy in treating NAFLD.

A comprehensive meta-analysis of stem cell therapy for liver failure: Assessing treatment efficacy and modality

INTRODUCTION AND OBJECTIVES

This meta-analysis aims to evaluate the efficacy of stem cell therapy (SCT) for liver failure.

MATERIALS AND METHODS

The study adhered to the recommended guidelines of the PRISMA statement. Eligible studies published prior to May 13, 2023, were comprehensively searched in databases including PubMed, Web of Science, and Embase. Quality assessment was conducted using the Cochrane risk-of-bias tool, and the standard mean differences were calculated for the clinical parameters. The hazard ratios were determined by extracting individual patient data from the Kaplan-Meier curve.

RESULTS

A total of 2,937 articles were retrieved, and eight studies were included in the final analysis. Most of the studies focused on HBV-related liver failure and were randomized controlled trials. All studies utilized mesenchymal stem cells (MSCs), with the majority (62.5%) being allogeneic. The analysis revealed that combining stem cell therapy with standard medical treatment or plasma exchange significantly enhanced patient survival and reduced MELD scores. Specifically, allogeneic stem cells showed superior efficacy in improving survival outcomes compared to autologous stem cells. Furthermore, deep vessel injection plus a single injection demonstrated better effectiveness than peripheral vessel injection plus multiple injections in reducing MELD scores.

CONCLUSIONS

This comprehensive analysis underscores the potential of MSC therapy in significantly improving survival and clinical outcomes in patients with liver failure, highlighting the superior benefits of allogeneic MSCs and deep vessel plus single injection administration.

Application of mesenchymal stem cells derived from the umbilical cord or Wharton's jelly and their extracellular vesicles in the treatment of various diseases

Mesenchymal stem cells (MSCs) originating from the umbilical cord (UC) or Wharton's jelly (WJ) have attracted substantial interest due to their potential to augment therapeutic approaches for a wide range of disorders. These cells demonstrate a wide range of capabilities in the process of differentiating into a multitude of cell types. Additionally, they possess a significant capacity for proliferation and are conveniently accessible. Furthermore, they possess a status of being immune-privileged, exhibit minimal tumorigenic characteristics, and raise minimal ethical concerns. Consequently, they are well-suited candidates for tissue regeneration and the treatment of diseases. Additionally, UC-derived MSCs offer a substantial yield compared to other sources. The therapeutic effects of these MSCs are closely associated with the release of nanosized extracellular vesicles (EVs), including exosomes and microvesicles (MVs), containing lipids, microRNAs, and proteins that facilitate intercellular communication. Due to their reduced tumorigenic and immunogenic characteristics, in addition to their convenient manipulability, EVs have arisen as a viable alternative for the management of disorders. The favorable characteristics of UC-MSCs or WJ-MSCs and their EVs have generated significant attention in clinical investigations encompassing diverse pathologies. Therefore, we present a review encompassing current preclinical and clinical investigations, examining the implications of UC-MSCs in diverse diseases, including those affecting bone, cartilage, skin, liver, kidney, neural, lung, cardiovascular, muscle, and retinal tissues, as well as conditions like cancer, diabetes, sepsis, and others.

Exosome prospects in the diagnosis and treatment of non-alcoholic fatty liver disease

The growing prevalence of NAFLD and its global health burden have provoked considerable research on possible diagnostic and therapeutic options for NAFLD. Although various pathophysiological mechanisms and genetic factors have been identified to be associated with NAFLD, its treatment remains challenging. In recent years, exosomes have attracted widespread attention for their role in metabolic dysfunctions and their efficacy as pathological biomarkers. Exosomes have also shown tremendous potential in treating a variety of disorders. With increasing evidence supporting the significant role of exosomes in NAFLD pathogenesis, their theragnostic potential has become a point of interest in NAFLD. Expectedly, exosome-based treatment strategies have shown promise in the prevention and amelioration of NAFLD in preclinical studies. However, there are still serious challenges in preparing, standardizing, and applying exosome-based therapies as a routine clinical option that should be overcome. Due to the great potential of this novel theragnostic agent in NAFLD, further investigations on their safety, clinical efficacy, and application standardization are highly recommended.

Enhancing clinical safety in bioengineered-root regeneration: The use of animal component-free medium

Background

Most studies used animal serum-containing medium for bioengineered-root regeneration, but ethical and safety issues raised by animal serum are a potentially significant risk for clinical use. Thus, this study aimed to find a safer method for bioengineered-root regeneration.

Methods

The biological properties of human dental pulp stem cells (hDPSCs) cultured in animal component-free (ACF) medium or serum-containing medium (5%, 10% serum-containing medium, SCM) were compared in vitro. hDPSCs were cultured in a three-dimensional (3D) environment with human-treated dentin matrix (hTDM). The capacity for odontogenesis was compared using quantitative real-time PCR (qPCR) and Western blot. Subsequently, the hDPSCs/hTDM complexes were transplanted into nude mice subcutaneously. Histological staining was then used to verify the regeneration effect in vivo.

Results

ACF medium promoted the migration of hDPSCs, but slightly inhibited the proliferation of hDPSCs in the first three days of culture compared to SCM. However, it had no significant effect on cell aging and apoptosis. After 7 days of 3D culture in ACF medium with hTDM, qPCR showed that DMP1, DSPP, OCN, RUNX2, and β-tubulin III were highly expressed in hDPSCs. In addition, 3D cultured hDPSCs/hTDM complexes in ACF medium regenerated dentin, pulp, and periodontal ligament-like tissues similar to SCM groups in vivo.

Conclusion

ACF medium was proved to be an alternative medium for bioengineered-root regeneration. The strategy of using ACF medium to regenerate bioengineered-root can improve clinical safety for tooth tissue engineering.

Human umbilical cord mesenchymal stem cell transplantation for the treatment of acute-on-chronic liver failure: protocol for a multicentre random double-blind placebo-controlled trial

INTRODUCTION

Acute-on-chronic liver failure (ACLF) is a prevalent and life-threatening liver disease with high short-term mortality. Although recent clinical trials on the use of mesenchymal stem cells (MSCs) for ACLF treatment have shown promising results, multicentre randomised controlled phase II clinical trials remain uncommon. The primary aim of this trial is to assess the safety and efficacy of different MSCs treatment courses for ACLF.

METHODS AND ANALYSIS

This is a multicentre, double-blind, two-stage, randomised and placebo-controlled clinical trial. In the first stage, 150 patients with ACLF will be enrolled and randomly assigned to either a control group (50 cases) or an MSCs treatment group (100 cases). They will receive either a placebo or umbilical cord-derived MSCs (UC-MSCs) treatment three times (at weeks 0, 1 and 2). In the second stage, 28 days after the first UC-MSCs infusion, surviving patients in the MSCs treatment group will be further randomly divided into MSCs-short and MSCs-prolonged groups at a 1:1 ratio. They will receive two additional rounds of placebo or UC-MSCs treatment at weeks 4 and 5. The primary endpoints are the transplant-free survival rate and the incidence of treatment-related adverse events. Secondary endpoints include international normalised ratio, total bilirubin, serum albumin, blood urea nitrogen, model for end-stage liver disease score and Child-Turcotte-Pugh score.

ETHICS AND DISSEMINATION

Ethical approval of this study has been obtained from the Fifth Medical Center of the Chinese PLA General Hospital (KY-2023-3-19-1). All results of the study will be submitted to international journals and international conferences for publication on completion of the study.

TRIAL REGISTRATION NUMBER

NCT05985863.

A case series on safety and tolerability of human umbilical cord-derived mesenchymal stem cells on patients in Malaysia

Umbilical cord-derived mesenchymal stem cells for regenerative therapy are a promising treatment option for chronic illnesses. Umbilical cord-derived mesenchymal stem cells offer several advantages over other sources, which makes them an attractive option in tissue repair and regeneration. This clinical study describes a 1-year follow-up on the safety and tolerance of umbilical cord-derived mesenchymal stem cell therapy on nine patients in Malaysia. Patients were assessed for adverse effects, and liver function tests were carried out on both pre- and post-treatments. Umbilical cord-derived mesenchymal stem cells' effectiveness and safety were assessed by follow-up evaluations. All nine patients responded positively towards umbilical cord-derived mesenchymal stem cell therapy, without any adverse effects. After umbilical cord-derived mesenchymal stem cell therapy, a significant improvement was observed in liver functioning test outcomes, as haematological parameters and tumour markers were stable. The present study concludes that umbilical cord-derived mesenchymal stem cell therapy is well tolerated by Malaysian patients; however, further clinical screening must be done over a large number of patients population.

Stem Cell-Based Strategies: The Future Direction of Bioartificial Liver Development

Acute liver failure (ALF) results from severe liver damage or end-stage liver disease. It is extremely fatal and causes serious health and economic burdens worldwide. Once ALF occurs, liver transplantation (LT) is the only definitive and recommended treatment; however, LT is limited by the scarcity of liver grafts. Consequently, the clinical use of bioartificial liver (BAL) has been proposed as a treatment strategy for ALF. Human primary hepatocytes are an ideal cell source for these methods. However, their high demand and superior viability prevent their widespread use. Hence, finding alternatives that meet the seed cell quality and quantity requirements is imperative. Stem cells with self-renewing, immunogenic, and differentiative capacities are potential cell sources. MSCs and its secretomes encompass a spectrum of beneficial properties, such as anti-inflammatory, immunomodulatory, anti-ROS (reactive oxygen species), anti-apoptotic, pro-metabolomic, anti-fibrogenesis, and pro-regenerative attributes. This review focused on the recent status and future directions of stem cell-based strategies in BAL for ALF. Additionally, we discussed the opportunities and challenges associated with promoting such strategies for clinical applications.

Pre-administration of human umbilical cord mesenchymal stem cells has better therapeutic efficacy in rats with D-galactosamine-induced acute liver failure

BACKGROUND

Acute liver failure (ALF) is characterized by an intense systemic inflammatory response, single or multiple organ system failure and high mortality. However, specific and effective treatments for ALF patients are still lacking. According to the current investigation, human umbilical cord mesenchymal stem cells (hUCMSCs) have shown remarkable potential to enhance the functional recovery of injured livers. We aimed to investigate the therapeutic effects of time-differentiated hUCMSCs administration regimens on ALF.

METHODS

The rat model of ALF was induced by D-galactosamine (D-gal), and hUCMSCs were administered via the tail vein 12 h before or 2 h after induction. The potential mechanisms of hUCMSCs in treatment of ALF, regulation cell subset and secretion of inflammatory factors, were verified by co-culturing with PBMCs in vitro. Liver function indicators were detected by an automatic biochemistry analyzer and inflammatory factors were obtained by ELISA detection. The distribution of hUCMSCs in rats after administration was followed by quantitative real-time fluorescence PCR.

RESULTS

The findings of the study discovered that administration of hUCMSCs 12 h prior to surgery could significantly improve the survival rate of rats, stabilize various liver function indicators in serum levels of ALT, AST, T-BIL, or ALB diminish inflammatory infiltration in liver tissue, and inhibit the secretion of inflammatory factors.

CONCLUSION

Our data showed that pre-transplantation of hUCMSCs had a better therapeutic effect on ALF rats, providing empirical evidence for preclinical studies. Thus, the timing of hUCMSCs transplantation is necessary for the optimal clinical treatment effect.

Invigorating human MSCs for transplantation therapy via Nrf2/DKK1 co-stimulation in an acute-on-chronic liver failure mouse model

BACKGROUND

Since boosting stem cell resilience in stressful environments is critical for the therapeutic efficacy of stem cell-based transplantations in liver disease, this study aimed to establish the efficacy of a transient plasmid-based preconditioning strategy for boosting the capability of mesenchymal stromal cells (MSCs) for anti-inflammation/antioxidant defenses and paracrine actions in recipient hepatocytes.

METHODS

Human adipose mesenchymal stem cells (hADMSCs) were subjected to transfer, either with or without the nuclear factor erythroid 2-related factor 2 (Nrf2)/Dickkopf1 (DKK1) genes, followed by exposure to TNF-α/H2O2. Mouse models were subjected to acute chronic liver failure (ACLF) and subsequently injected with either transfected or untransfected MSCs. These hADMSCs and ACLF mouse models were used to investigate the interaction between Nrf2/DKK1 and the hepatocyte receptor cytoskeleton-associated protein 4 (CKAP4).

RESULTS

Activation of Nrf2 and DKK1 enhanced the anti-stress capacity of MSCs in vitro. In a murine model of ACLF, transient co-overexpression of Nrf2 and DKK1 via plasmid transfection improved MSC resilience against inflammatory and oxidative assaults, boosted MSC transplantation efficacy, and promoted recipient liver regeneration due to a shift from the activation of the anti-regenerative IFN-γ/STAT1 pathway to the pro-regenerative IL-6/STAT3 pathway in the liver. Importantly, the therapeutic benefits of MSC transplantation were nullified when the receptor CKAP4, which interacts with DKK1, was specifically removed from recipient hepatocytes. However, the removal of the another receptor low-density lipoprotein receptor-related protein 6 (LRP6) had no impact on the effectiveness of MSC transplantation. Moreover, in long-term observations, no tumorigenicity was detected in mice following transplantation of transiently preconditioned MSCs.

CONCLUSIONS

Co-stimulation with Nrf2/DKK1 safely improved the efficacy of human MSC-based therapies in murine models of ACLF through CKAP4-dependent paracrine mechanisms.

TC14012 enhances the anti-fibrosis effects of UC-MSCs on the liver by reducing collagen accumulation and ameliorating inflammation

BACKGROUND

Mesenchymal stem cells (MSCs) are attracting attention as a promising cell-based therapy for the treatment of liver fibrosis or cirrhosis. However, the strategies and potential mechanisms of MSCs therapy need further investigation. The CXCL12/CXCR4/CXCR7 chemokine axis is well known to regulate cell migration and is involved in the regulation of liver fibrosis. This study aims to treat MSCs with a CXCR7-specific agonist to evaluate its therapeutic effects on hepatic fibrosis and potential mechanisms.

METHODS

TC14012, a potent agonist of CXCR7, has been used to pretreat human umbilical cord-derived MSCs (UC-MSCs) and assess its effect on proliferation, apoptosis, migration, immunoregulation, and gene regulatory network. Then, CCl4-induced liver fibrosis mice models were used to evaluate the therapeutic effect and mechanism of TC14012-treated UC-MSCs for treating hepatic fibrosis.

RESULTS

TC14012 increased CXCR7 expression in UC-MSCs. Notably, co-culture of liver sinusoidal endothelial cells (LSEC) with TC14012-pretreated UC-MSCs increased CXCR7 expression in LSEC. Additionally, TC14012 promoted cell migration and mediated the immunoregulation of UC-MSCs. Compared to UC-MSCs without TC14012 pretreatment, UC-MSCs treated with TC14012 ameliorated live fibrosis by restoring CXCR7 expression, reducing collagen fibril accumulation, inhibiting hepatic stellate cells activation, and attenuating the inflammatory response.

CONCLUSION

This study suggests that TC14012 pretreatment can enhance the therapeutic effects of UC-MSCs on liver fibrosis, mainly by promoting the migration and immunoregulation of MSCs.

Therapeutic potential of stem cells in regeneration of liver in chronic liver diseases: Current perspectives and future challenges

The deposition of extracellular matrix and hyperplasia of connective tissue characterizes chronic liver disease called hepatic fibrosis. Progression of hepatic fibrosis may lead to hepatocellular carcinoma. At this stage, only liver transplantation is a viable option. However, the number of possible liver donors is less than the number of patients needing transplantation. Consequently, alternative cell therapies based on non-stem cells (e.g., fibroblasts, chondrocytes, keratinocytes, and hepatocytes) therapy may be able to postpone hepatic disease, but they are often ineffective. Thus, novel stem cell-based therapeutics might be potentially important cutting-edge approaches for treating liver diseases and reducing patient' suffering. Several signaling pathways provide targets for stem cell interventions. These include pathways such as TGF-β, STAT3/BCL-2, NADPH oxidase, Raf/MEK/ERK, Notch, and Wnt/β-catenin. Moreover, mesenchymal stem cells (MSCs) stimulate interleukin (IL)-10, which inhibits T-cells and converts M1 macrophages into M2 macrophages, producing an anti-inflammatory environment. Furthermore, it inhibits the action of CD4+ and CD8+ T cells and reduces the activity of TNF-α and interferon cytokines by enhancing IL-4 synthesis. Consequently, the immunomodulatory and anti-inflammatory capabilities of MSCs make them an attractive therapeutic approach. Importantly, MSCs can inhibit the activation of hepatic stellate cells, causing their apoptosis and subsequent promotion of hepatocyte proliferation, thereby replacing dead hepatocytes and reducing liver fibrosis. This review discusses the multidimensional therapeutic role of stem cells as cell-based therapeutics in liver fibrosis.

Human umbilical cord-derived mesenchymal stem cells for the treatment of decompensated cirrhosis (MSC-DLC-1): a dose-escalation, phase I trial protocol

INTRODUCTION

There are limited therapeutic options to efficiently treat patients with decompensated liver cirrhosis. This trial aims to explore the efficacy and safety of human umbilical cord-derived mesenchymal stem cells (UC-MSCs) for the treatment of patients with decompensated liver cirrhosis.

METHODS AND ANALYSIS

This study is an open-label, dose-escalation, one-armed phase I trial. A single injection of UC-MSCs will be administered in a predetermined dose in each cohort (5.0×107, 1.0×108, 1.5×108 or 2.0×108 cells) according to the '3+3' rule. The primary evaluation measures will include the incidence of adverse events and the change in the Model for End-stage Liver Disease (MELD) score from baseline to the 28th day. Secondary evaluation measures will be evaluated at baseline and at each follow-up point. These measures will include the change in the MELD score from baseline to each follow-up point, the incidence of each complication associated with decompensated cirrhosis, liver transplant-free survival and the incidence of liver failure, among other relevant measures. All patients will be followed up for 24 months. This study will evaluate whether the use of UC-MSCs to treat patients with decompensated liver cirrhosis is safe and tolerable.

ETHICS AND DISSEMINATION

The study has been approved by the Chinese People's Liberation Army General Hospital (Approval#: 2018-107-D-4). Once conducted, the results from the study will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT05227846.

Consensus document on acute-on-chronic liver failure (ACLF) established by the Mexican Association of Hepatology

Acute-on chronic liver failure (ACLF) has been an intensively debated topic mainly due to the lack of a unified definition and diagnostic criteria. The growing number of publications describing the mechanisms of ACLF development, the progression of the disease, outcomes and treatment has contributed to a better understanding of the disease, however, it has also sparked the debate about this condition. As an attempt to provide medical professionals with a more uniform definition that could be applied to our population, the first Mexican consensus was performed by a panel of experts in the area of hepatology in Mexico. We used the most relevant and impactful publications along with the clinical and research experience of the consensus participants. The consensus was led by 4 coordinators who provided the most relevant bibliography by doing an exhaustive search on the topic. The entire bibliography was made available to the members of the consensus for consultation at any time during the process and six working groups were formed to develop the following sections: 1.- Generalities, definitions, and criteria, 2.- Pathophysiology of cirrhosis, 3.- Genetics in ACLF, 4.- Clinical manifestations, 5.- Liver transplantation in ACLF, 6.- Other treatments.

Novel Therapeutic Approaches in Treatment of Acute-on-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF), a clinical syndrome that can develop at any stage in the progression of cirrhotic liver disease, is characterized by an acute decompensation in liver function with associated multiorgan failure and high short-term mortality. Current evidence points to ACLF being reversible, particularly in those at the lower end of the severity spectrum. However, there are no specific treatments for ACLF, and overall outcomes remain poor. Expedited liver transplantation as a treatment option is limited by organ shortage and a lack of priority allocation for this indication. Other options are therefore urgently needed, and our improved understanding of the condition has led to significant efforts to develop novel therapies. In conclusion, this review aims to summarize the current understanding of the pathophysiological processes involved in the onset, progression, and recovery of ACLF and discuss novel therapies under development.

Multiple Dimensions of using Mesenchymal Stem Cells for Treating Liver Diseases: From Bench to Beside

Liver diseases impose a huge burden worldwide. Although hepatocyte transplantation has long been considered as a potential strategy for treating liver diseases, its clinical implementation has created some obvious limitations. As an alternative strategy, cell therapy, particularly mesenchymal stem cell (MSC) transplantation, is widely used in treating different liver diseases, including acute liver disease, acute-on-chronic liver failure, hepatitis B/C virus, autoimmune hepatitis, nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, alcoholic liver disease, liver fibrosis, liver cirrhosis, and hepatocellular carcinoma. Here, we summarize the status of MSC transplantation in treating liver diseases, focusing on the therapeutic mechanisms, including differentiation into hepatocyte-like cells, immunomodulating function with a variety of immune cells, paracrine effects via the secretion of various cytokines and extracellular vesicles, and facilitation of homing and engraftment. Some improved perspectives and current challenges are also addressed. In summary, MSCs have great potential in the treatment of liver diseases based on their multi-faceted characteristics, and more accurate mechanisms and novel therapeutic strategies stemming from MSCs will facilitate clinical practice.

Arouse potential stemness: Intrinsic and acquired stem cell therapeutic strategies for advanced liver diseases

Liver diseases are a major health issue, and prolonged liver injury always progresses. Advanced liver disorders impair liver regeneration. Millions of patients die yearly worldwide, even with the available treatments of liver transplantation and artificial liver support system. With its abundant cell resources and significant differentiative potential, stem cell therapy is a viable treatment for various disorders and offers hope to patients waiting for orthotopic liver transplantation. Considering such plight, stem cell therapeutic strategies deliver hope to the patients. Moreover, we conclude intrinsic and acquired perspectives based on stem cell sources. The properties and therapeutic uses of these stem cells' specific types or sources were then reviewed. Owing to the recent investigations of the above cells, a safe and effective therapy will emerge for advanced liver diseases soon.

Meta-analysis on last ten years of clinical injection of bone marrow-derived and umbilical cord MSC to reverse cirrhosis or rescue patients with acute-on-chronic liver failure

BACKGROUND

Recent studies have shown that mesenchymal stem cell (MSC) therapy has potential therapeutic effects for patients with end-stage liver diseases. However, a consensus on the efficacy and safety of MSCs has not been reached.

METHODS

A systemic literature review was conducted by searching the Cochrane Library and PubMed databases for articles that evaluated the impact of MSC therapy on the outcomes among patients with end-stage liver disease. Various parameters, including pre- and post-treatment model of end-stage liver disease (MELD) score, serum albumin (ALB), total bilirubin (TB), coagulation function, aminotransferase, and survival rate, were evaluated.

RESULTS

This meta-analysis included a final total of 13 studies and 854 patients. The results indicated improved liver parameters following MSC therapy at different time points, including in terms of MELD score, TB level, and ALB level, compared with conventional treatment. Furthermore, the MSC treatment increased the overall survival rate among patients with liver cirrhosis and acute-on-chronic liver failure (ACLF). The changes in transaminase level and coagulation function differed between the different therapies at various post-treatment time points, indicating that MSC therapy provided no significant benefits in this regard. The further subgroup analysis stratified by liver background revealed that patients with ACLF benefit more from MSC therapy at most time points with improved liver function, including in terms of MELD score, TB level, and ALB level. In addition, no serious side effects or adverse events were reported following MSC therapy.

CONCLUSIONS

The meta-analysis results suggest that MSC therapy is safe and results in improved liver function and survival rates among patients with end-stage liver disease. The subgroup analysis stratified by liver background indicated that patients with ACLF benefit more from MSC therapy than patients with liver cirrhosis at most time points.

Isolation, culture, and delivery considerations for the use of mesenchymal stem cells in potential therapies for acute liver failure

Acute liver failure (ALF) is a high-mortality syndrome for which liver transplantation is considered the only effective treatment option. A shortage of donor organs, high costs and surgical complications associated with immune rejection constrain the therapeutic effects of liver transplantation. Recently, mesenchymal stem cell (MSC) therapy was recognized as an alternative strategy for liver transplantation. Bone marrow mesenchymal stem cells (BMSCs) have been used in clinical trials of several liver diseases due to their ease of acquisition, strong proliferation ability, multipotent differentiation, homing to the lesion site, low immunogenicity and anti-inflammatory and antifibrotic effects. In this review, we comprehensively summarized the harvest and culture expansion strategies for BMSCs, the development of animal models of ALF of different aetiologies, the critical mechanisms of BMSC therapy for ALF and the challenge of clinical application.

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.

The high level of IL-1β in the serum of ACLF patients induces increased IL-8 expression in hUC-MSCs and reduces the efficacy of hUC-MSCs in liver failure

BACKGROUND

Stem cells play a therapeutic role mainly through immunoregulation. However, the immunomodulatory function of stem cells may be affected by inflammation-related factors in patients' serum. Therefore, this study aims to investigate the possible mechanism by which acute-on-chronic liver failure (ACLF) patient serum influences the efficacy of hUC-MSCs.

METHODS

The serum of surviving and dead ACLF patients was collected to culture hUC-MSCs in vitro, and the hUC-MSCs cultured in the serum of ACLF patients were used to treat acute liver failure (ALF) rats. The therapeutic effect on the rats was evaluated by a survival curve, the transaminase level and liver histopathology. The expression of cytokines in hUC-MSCs was detected by Q-PCR and ELISA.

RESULTS

Serum pretreatment reduced the therapeutic effect of hUC-MSCs on ALF, especially pretreatment in the serum from dead ACLF patients. After hUC-MSCs were cultured in the serum of surviving or dead ACLF patients, the most differentially expressed factor was IL-8. Interfering with the expression of IL-8 in hUC-MSCs can improve the therapeutic effect of hUC-MSCs on ALF. The high level of IL-1β in the serum of dead ACLF patients causes the increased expression of IL-8 in hUC-MSCs through the activation of the NF-κB signaling pathway. Meanwhile, we found that the neutralizing IL-1β in serum from dead ACLF patients can improve the therapeutic effect of hUC-MSCs on ALF.

CONCLUSION

The high level of IL-1β in ACLF serum can promote the expression of IL-8 in hUC-MSCs through the NF-κB signaling pathway, thus reducing the effect of hUC-MSCs on ALF.

Liver Disease and Cell Therapy: Advances Made and Remaining Challenges

The limited availability of organs for liver transplantation, the ultimate curative treatment for end stage liver disease, has resulted in a growing and unmet need for alternative therapies. Mesenchymal stromal cells (MSCs) with their broad ranging anti-inflammatory and immunomodulatory properties have therefore emerged as a promising therapeutic agent in treating inflammatory liver disease. Significant strides have been made in exploring their biological activity. Clinical application of MSC has shifted the paradigm from using their regenerative potential to one which harnesses their immunomodulatory properties. Reassuringly, MSCs have been extensively investigated for over 30 years with encouraging efficacy and safety data from translational and early phase clinical studies, but questions remain about their utility. Therefore, in this review, we examine the translational and clinical studies using MSCs in various liver diseases and their impact on dampening immune-mediated liver damage. Our key observations include progress made thus far with use of MSCs for clinical use, inconsistency in the literature to allow meaningful comparison between different studies and need for standardized protocols for MSC manufacture and administration. In addition, the emerging role of MSC-derived extracellular vesicles as an alternative to MSC has been reviewed. We have also highlighted some of the remaining clinical challenges that should be addressed before MSC can progress to be considered as therapy for patients with liver disease.

PPARγ-dependent hepatic macrophage switching acts as a central hub for hUCMSC-mediated alleviation of decompensated liver cirrhosis in rats

BACKGROUND

Decompensated liver cirrhosis (DLC), a terminal-stage complication of liver disease, is a major cause of morbidity and mortality in patients with hepatopathies. Human umbilical cord mesenchymal stem cell (hUCMSC) therapy has emerged as a novel treatment alternative for the treatment of DLC. However, optimized therapy protocols and the associated mechanisms are not entirely understood.

METHODS

We constructed a DLC rat model consistent with the typical clinical characteristics combined use of PB and CCL₄. Performing dynamic detection of liver morphology and function in rats for 11 weeks, various disease characteristics of DLC and the therapeutic effect of hUCMSCs on DLC in experimental rats were thoroughly investigated, according to ascites examination, histopathological, and related blood biochemical analyses. Flow cytometry analysis of rat liver, immunofluorescence, and RT-qPCR was performed to examine the changes in the liver immune microenvironment after hucMSCs treatment. We performed RNA-seq analysis of liver and primary macrophages and hUCMSCs co-culture system in vitro to explore possible signaling pathways. PPARγ antagonist, GW9662, and clodronate liposomes were used to inhibit PPAR activation and pre-exhaustion of macrophages in DLC rats' livers, respectively.

RESULTS

We found that changing the two key issues, the frequency and initial phase of hUCMSCs infusion, can affect the efficacy of hUCMSCs, and the optimal hUCMSCs treatment schedule is once every week for three weeks at the early stage of DLC progression, providing the best therapeutic effect in reducing mortality and ascites, and improving liver function in DLC rats. hUCMSCs treatment skewed the macrophage phenotype from M1-type to M2-type by activating the PPARγ signaling pathway in the liver, which was approved by primary macrophages and hUCMSCs co-culture system in vitro. Both inhibition of PPARγ activation with GW9662 and pre-exhaustion of macrophages in DLC rats' liver abolished the regulation of hUCMSCs on macrophage polarization, thus attenuating the beneficial effect of hUCMSCs treatment in DLC rats.

CONCLUSIONS

These data demonstrated that the optimal hUCMSCs treatment effectively inhibits the ascites formation, prolongs survival and significantly improves liver structure and function in DLC rats through the activation of the PPARγ signaling pathway within liver macrophages. Our study compared the efficacy of different hUCMSCs infusion regimens for DLC, providing new insights on cell-based therapies for regenerative medicine.

Therapeutic potentials of mesenchymal stromal cells-derived extracellular vesicles in liver failure and marginal liver graft rehabilitation: a scoping review

Liver failure includes distinct subgroups of diseases: Acute liver failure (ALF) without preexisting cirrhosis, acute-on-chronic liver failure (ACLF) (severe form of cirrhosis associated with organ failures and excess mortality), and liver fibrosis (LF). Inflammation plays a key role in ALF, LF, and more specifically in ACLF for which we have currently no treatment other than liver transplantation (LT). The increasing incidence of marginal liver grafts and the shortage of liver grafts require us to consider strategies to increase the quantity and quality of available liver grafts. Mesenchymal stromal cells (MSCs) have shown beneficial pleiotropic properties with limited translational potential due to the pitfalls associated with their cellular nature. MSC-derived extracellular vesicles (MSC-EVs) are innovative cell-free therapeutics for immunomodulation and regenerative purposes. MSC-EVs encompass further advantages: pleiotropic effects, low immunogenicity, storage stability, good safety profile, and possibility of bioengineering. Currently, no human studies explored the impact of MSC-EVs on liver disease, but several preclinical studies highlighted their beneficial effects. In ALF and ACLF, data showed that MSC-EVs attenuate hepatic stellate cells activation, exert antioxidant, anti-inflammatory, anti-apoptosis, anti-ferroptosis properties, and promote regeneration of the liver, autophagy, and improve metabolism through mitochondrial function recovery. In LF, MSC-EVs demonstrated anti-fibrotic properties associated with liver tissue regeneration. Normothermic-machine perfusion (NMP) combined with MSC-EVs represents an attractive therapy to improve liver regeneration before LT. Our review suggests a growing interest in MSC-EVs in liver failure and gives an appealing insight into their development to rehabilitate marginal liver grafts through NMP.

Acute-on-chronic liver failure: far to go-a review

Acute-on-chronic liver failure (ACLF) has been recognized as a severe clinical syndrome based on the acute deterioration of chronic liver disease and is characterized by organ failure and high short-term mortality. Heterogeneous definitions and diagnostic criteria for the clinical condition have been proposed in different geographic regions due to the differences in aetiologies and precipitating events. Several predictive and prognostic scores have been developed and validated to guide clinical management. The specific pathophysiology of ACLF remains uncertain and is mainly associated with an intense systemic inflammatory response and immune-metabolism disorder based on current evidence. For ACLF patients, standardization of the treatment paradigm is required for different disease stages that may provide targeted treatment strategies for individual needs.

Recent advances in pre-conditioned mesenchymal stem/stromal cell (MSCs) therapy in organ failure; a comprehensive review of preclinical studies

Mesenchymal stem/stromal cells (MSCs)-based therapy brings the reassuring capability to regenerative medicine through their self-renewal and multilineage potency. Also, they secret a diversity of mediators, which are complicated in moderation of deregulated immune responses, and yielding angiogenesis in vivo. Nonetheless, MSCs may lose biological performance after procurement and prolonged expansion in vitro. Also, following transplantation and migration to target tissue, they encounter a harsh milieu accompanied by death signals because of the lack of proper tensegrity structure between the cells and matrix. Accordingly, pre-conditioning of MSCs is strongly suggested to upgrade their performances in vivo, leading to more favored transplantation efficacy in regenerative medicine. Indeed, MSCs ex vivo pre-conditioning by hypoxia, inflammatory stimulus, or other factors/conditions may stimulate their survival, proliferation, migration, exosome secretion, and pro-angiogenic and anti-inflammatory characteristics in vivo. In this review, we deliver an overview of the pre-conditioning methods that are considered a strategy for improving the therapeutic efficacy of MSCs in organ failures, in particular, renal, heart, lung, and liver.

Liver cell therapies: cellular sources and grafting strategies

The liver has a complex cellular composition and a remarkable regenerative capacity. The primary cell types in the liver are two parenchymal cell populations, hepatocytes and cholangiocytes, that perform most of the functions of the liver and that are helped through interactions with non-parenchymal cell types comprising stellate cells, endothelia and various hemopoietic cell populations. The regulation of the cells in the liver is mediated by an insoluble complex of proteins and carbohydrates, the extracellular matrix, working synergistically with soluble paracrine and systemic signals. In recent years, with the rapid development of genetic sequencing technologies, research on the liver's cellular composition and its regulatory mechanisms during various conditions has been extensively explored. Meanwhile breakthroughs in strategies for cell transplantation are enabling a future in which there can be a rescue of patients with end-stage liver diseases, offering potential solutions to the chronic shortage of livers and alternatives to liver transplantation. This review will focus on the cellular mechanisms of liver homeostasis and how to select ideal sources of cells to be transplanted to achieve liver regeneration and repair. Recent advances are summarized for promoting the treatment of end-stage liver diseases by forms of cell transplantation that now include grafting strategies.

Bone marrow mesenchymal stem cell-derived small extracellular vesicles promote liver regeneration via miR-20a-5p/PTEN

Balancing hepatocyte death and proliferation is key to non-transplantation treatments for acute liver failure (ALF), which has a high short-term mortality rate. Small extracellular vesicles (sEVs) may act as mediators in the repair of damaged liver tissue by mesenchymal stem cells (MSCs). We aimed to investigate the efficacy of human bone marrow MSC-derived sEVs (BMSC-sEVs) in treating mice with ALF and the molecular mechanisms involved in regulating hepatocyte proliferation and apoptosis. Small EVs and sEV-free BMSC concentrated medium were injected into mice with LPS/D-GalN-induced ALF to assess survival, changes in serology, liver pathology, and apoptosis and proliferation in different phases. The results were further verified in vitro in L-02 cells with hydrogen peroxide injury. BMSC-sEV-treated mice with ALF had higher 24 h survival rates and more significant reductions in liver injury than mice treated with sEV-free concentrated medium. BMSC-sEVs reduced hepatocyte apoptosis and promoted cell proliferation by upregulating miR-20a-5p, which targeted the PTEN/AKT signaling pathway. Additionally, BMSC-sEVs upregulated the mir-20a precursor in hepatocytes. The application of BMSC-sEVs showed a positive impact by preventing the development of ALF, and may serve as a promising strategy for promoting ALF liver regeneration. miR-20a-5p plays an important role in liver protection from ALF by BMSC-sEVs.

Cellular therapies in liver and pancreatic diseases

Over the past two decades, developments in regenerative medicine in gastroenterology have been greatly enhanced by the application of stem cells, which can self-replicate and differentiate into any somatic cell. The discovery of induced pluripotent stem cells has opened remarkable perspectives on tissue regeneration, including their use as a bridge to transplantation or as supportive therapy in patients with organ failure. The improvements in DNA manipulation and gene editing strategies have also allowed to clarify the physiopathology and to correct the phenotype of several monogenic diseases, both in vivo and in vitro. Further progress has been made with the development of three-dimensional cultures, known as organoids, which have demonstrated morphological and functional complexity comparable to that of a miniature organ. Hence, owing to its protean applications and potential benefits, cell and organoid transplantation has become a hot topic for the management of gastrointestinal diseases. In this review, we describe current knowledge on cell therapies in hepatology and pancreatology, providing insight into their future applications in regenerative medicine.

Stem cell therapy: a novel approach against emerging and re-emerging viral infections with special reference to SARS-CoV-2

The past several decades have witnessed the emergence and re-emergence of many infectious viral agents, flaviviruses, influenza, filoviruses, alphaviruses, and coronaviruses since the advent of human deficiency virus (HIV). Some of them even become serious threats to public health and have raised major global health concerns. Several different medicinal compounds such as anti-viral, anti-malarial, and anti-inflammatory agents, are under investigation for the treatment of these viral diseases. These therapies are effective improving recovery rates and overall survival of patients but are unable to heal lung damage caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Therefore, there is a critical need to identify effective treatments to combat this unmet clinical need. Due to its antioxidant and immunomodulatory properties, stem cell therapy is considered a novel approach to regenerate damaged lungs and reduce inflammation. Stem cell therapy uses a heterogeneous subset of regenerative cells that can be harvested from various adult tissue types and is gaining popularity due to its prodigious regenerative potential as well as immunomodulatory and anti-inflammatory properties. These cells retain expression of cluster of differentiation markers (CD markers), interferon-stimulated gene (ISG), reduce expression of pro-inflammatory cytokines and, show a rapid proliferation rate, which makes them an attractive tool for cellular therapies and to treat various inflammatory and viral-induced injuries. By examining various clinical studies, this review demonstrates positive considerations for the implications of stem cell therapy and presents a necessary approach for treating virally induced infections in patients.

Acute liver failure: A systematic review and network meta-analysis of optimal type of stem cells in animal models

BACKGROUND

The therapeutic effects of various stem cells in acute liver failure (ALF) have been demonstrated in preclinical studies. However, the specific type of stem cells with the highest therapeutic potential has not been determined.

AIM

To validate the efficacy of stem cells in ALF model and to identify the most promising stem cells.

METHODS

A search was conducted on the PubMed, Web of Science, Embase, Scopus, and Cochrane databases from inception to May 3, 2022, and updated on November 16, 2022 to identify relevant studies. Two independent reviewers performed the literature search, identification, screening, quality assessment, and data extraction.

RESULTS

A total of 89 animal studies were included in the analysis. The results of traditional meta-analysis showed that stem cell therapy could significantly reduce the serum levels of alanine aminotransferase [weighted mean difference (WMD) = -181.05 (-191.71, -170.39)], aspartate aminotransferase [WMD = -309.04 (-328.45, -289.63)], tumor necrosis factor-alpha [WMD = -8.75 (-9.93, -7.56)], and interleukin-6 [WMD = -10.43 (-12.11, -8.76)] in animal models of ALF. Further subgroup analysis and network meta-analysis showed that although mesenchymal stem cells are the current research hotspot, the effect of liver stem cells (LSCs) on improving liver function is significantly better than that of the other five types of stem cells. In addition, the ranking results showed that the possibility of LSCs improving liver function ranked first. This fully proves the great therapeutic potential of LSCs, which needs to be paid more attention in the future.

CONCLUSION

LSCs may have a higher therapeutic potential. Further high-quality animal experiments are needed to explore the most effective stem cells for ALF.

Therapeutic Efficiency of Nasal Mucosa-Derived Ectodermal Mesenchymal Stem Cells in Rats with Acute Hepatic Failure

Background

Liver transplantation is limited by the insufficiency of liver organ donors when treating end-stage liver disease or acute liver failure (ALF). Ectodermal mesenchymal stem cells (EMSCs) derived from nasal mucosa have emerged as an alternative cell-based therapy. However, the role of EMSCs in acute liver failure remains unclear.

Methods

EMSCs were obtained from the nasal mucosa tissue of rats. First, EMSCs were seeded on the gelatin-chitosan scaffolds, and the biocompatibility was evaluated. Next, the protective effects of EMSCs were investigated in carbon tetrachloride- (CCl₄-) induced ALF rats. Finally, we applied an indirect coculture system to analyze the paracrine effects of EMSCs on damaged hepatocytes. A three-step nontransgenic technique was performed to transform EMSCs into hepatocyte-like cells (HLCs) in vitro.

Results

EMSCs exhibited a similar phenotype to other mesenchymal stem cells along with self-renewal and multilineage differentiation capabilities. EMSC-seeded gelatin-chitosan scaffolds can increase survival rates and ameliorate liver function and pathology of ALF rat models. Moreover, transplanted EMSCs can secrete paracrine factors to promote hepatocyte regeneration, targeted migration, and transdifferentiate into HLCs in response to the liver's microenvironment, which will then repair or replace the damaged hepatocytes. Similar to mature hepatocytes, HLCs generated from EMSCs possess functions of expressing specific hepatic markers, storing glycogen, and producing urea.

Conclusions

These results confirmed the feasibility of EMSCs in acute hepatic failure treatment. To our knowledge, this is the first time that EMSCs are used in the therapy of liver diseases. EMSCs are expected to be a novel and promising cell source in liver tissue engineering.

Therapeutic Potential of Mesenchymal Stem Cells in the Treatment of Epilepsy and Their Interaction with Antiseizure Medications

Epilepsy is a life-threatening neurological disease that affects approximately 70 million people worldwide. Although the vast majority of patients may be successfully managed with currently used antiseizure medication (ASM), the search for alternative therapies is still necessary due to pharmacoresistance in about 30% of patients with epilepsy. Here, we review the effects of ASMs on stem cell treatment when they could be, as expected, co-administered. Indeed, it has been reported that ASMs produce significant effects on the differentiation and determination of stem cell fate. In addition, we discuss more recent findings on mesenchymal stem cells (MSCs) in pre-clinical and clinical investigations. In this regard, their ability to differentiate into various cell types, reach damaged tissues and produce and release biologically active molecules with immunomodulatory/anti-inflammatory and regenerative properties make them a high-potential therapeutic tool to address neuroinflammation in different neurological disorders, including epilepsy. Overall, the characteristics of MSCs to be genetically engineered, in order to replace dysfunctional elements with the aim of restoring normal tissue functioning, suggested that these cells could be good candidates for the treatment of epilepsy refractory to ASMs. Further research is required to understand the potential of stem cell treatment in epileptic patients and its interaction with ASMs.

HNF4α overexpression enhances the therapeutic potential of umbilical cord mesenchymal stem/stromal cells in mice with acute liver failure

Human umbilical cord mesenchymal stem/stromal cells (hUMSCs) hold promise for treating acute liver failure (ALF). Here, we investigated the therapeutic effect of hUMSCs overexpressing hepatocyte nuclear factor 4α (HNF4α), a transcription factor important for maintaining hepatocyte identity and hepatic functions, in ALF, compared with hUMSCs without overexpression of HNF4α (CON-hUMSCs). The cells were administered into mice via the tail vein for 24 h before exposure to lipopolysaccharide/d-galactosamine (LPS/d-GalN) for 6 h by intraperitoneal injection. HNF4α-hUMSCs ameliorated liver injury in ALF better than CON-hUMSCs. The overexpression of HNF4α enhanced the transcription of interleukin (IL)-10 and promoted M2 macrophage polarization through the IL-10/signal transducer and activator of transcription 3 (STAT3) pathway. HNF4α-hUMSCs could exert a more pronounced therapeutic effect on ALF than CON-hUMSCs, providing a novel therapy for ALF.

Hyperthermia-stimulated tonsil-mesenchymal stromal cells suppress hematological cancer cells through downregulation of IL-6

There are contradictory reports on the use of mesenchymal stromal cells (MSCs) in cancer therapy. Variable outcomes have been associated with several factors including cancer pathology, experimental procedure, MSC source tissue, and individual genetic differences. It is also known that MSCs exert their therapeutic effects with various paracrine factors released from these cells. The profiles of the factors released from MSCs are altered by heat shock, hypoxia, oxidative stress, starvation or various agents such as inflammatory cytokines, and their therapeutic potential is affected. In this study, the antitumor potential of conditioned media (CM), which contains paracrine factors, of mild hyperthermia-stimulated mesenchymal stromal cells derived from lymphoid organ tonsil tissue (T-MSC) was investigated in comparison with CM obtained from T-MSCs grew under normal culture conditions. CM was obtained from T-MSCs that were successfully isolated from palatine tonsil tissue and characterized. The cytotoxic effect of CM on the growth of hematological cancer cell lines at different concentrations (1:1 and 1:2) was demonstrated by methylthiazoldiphenyl-tetrazolium bromide analysis. In addition, the apoptotic effect of T-MSC-CM treatment was evaluated on the cancer cells using Annexin-V/PI detection method by flow cytometry. The pro/anti-apoptotic and cytokine-related gene expressions were also analyzed by real-time polymerase chain reaction post T-MSC-CM treatment. In conclusion, we demonstrated that the factors released from hyperthermia-stimulated T-MSCs induced apoptosis in hematological cancer cell lines in a dose-dependent manner. Importantly, our results at the transcriptional level support that the factors and cytokines released from hyperthermia-stimulated T-MSC may exert antitumoral effects in cancer cells by downregulation of IL-6 that promotes tumorigenesis. These findings reveal that T-MSC-CM can be a powerful cell-free therapeutical strategy for cancer therapy.

Serum metabolic effects of corn oligopeptides with 7-day supplementation on early post-surgery primary liver cancer patients: a double-blind randomized controlled trial

BACKGROUND

Liver cancer as the main leading cancer has caused heavy burdens globally. The prognosis of liver cancer is closely related with postoperative nutrition support. Corn oligopeptides (COPs) are protein hydrolysates produced by enzymatic treatments, which have shown potential bioactivities, such as inhibiting angiotensin I-converting enzyme, resisting lipid peroxidation and anti-oxidant. However, the correlation between COPs and liver cancer patients is still unknown and the potential mechanism of COPs on liver cancer is unclear as well. The aim of this study was to assess effects of 7-day intervention of COPs after surgery on liver function and serum metabolic profiles of liver cancer patients.

METHODS

Patients were assigned into COPs intervention group (n=50) and control group (n=91) for 7 days. Investigations were scheduled at 1st day and 7th day after liver resection surgery respectively, mainly including anthropometric, biochemical indexes and liquid chromatography-mass spectrometry (LC/MS) analysis.

RESULTS

Seven-day supplementation of COPs on early post-surgery liver cancer patients down-regulated levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin, direct bilirubin and up-regulated prothrombin time activity and prealbumin levels. LC/MS analysis revealed metabolic signatures including regulation of 16 metabolites, which was closely related with two metabolic pathways (nicotinate and nicotinamide metabolism, fatty acid metabolism).

CONCLUSIONS

COPs supplementation has displayed the potentials on alleviating the injury of liver function and it may be due to regulation of fatty acid metabolism, nicotinate and nicotinamide metabolism, lipid peroxidation and anti-inflammatory action. More researches are warranted in future to confirm the exact mechanisms.

The Mechanisms of Systemic Inflammatory and Immunosuppressive Acute-on-Chronic Liver Failure and Application Prospect of Single-Cell Sequencing

Acute-on-chronic liver failure (ACLF) is a complex clinical syndrome, and patients often have high short-term mortality. It occurs with intense systemic inflammation, often accompanied by a proinflammatory event (such as infection or alcoholic hepatitis), and is closely related to single or multiple organ failure. Liver inflammation begins when innate immune cells (such as Kupffer cells (KCs)) are activated by binding of pathogen-associated molecular patterns (PAMPs) from pathogenic microorganisms or damage-associated molecular patterns (DAMPs) of host origin to their pattern recognition receptors (PRRs). Activated KCs can secrete inflammatory factors as well as chemokines and recruit bone marrow-derived cells such as neutrophils and monocytes to the liver to enhance the inflammatory process. Bacterial translocation may contribute to ACLF when there are no obvious precipitating events. Immunometabolism plays an important role in the process (including mitochondrial dysfunction, amino acid metabolism, and lipid metabolism). The late stage of ACLF is mainly characterized by immunosuppression. In this process, the dysfunction of monocyte and macrophage is reflected in the downregulation of HLA-DR and upregulation of MER tyrosine kinase (MERTK), which weakens the antigen presentation function and reduces the secretion of inflammatory cytokines. We also describe the specific function of bacterial translocation and the gut-liver axis in the process of ACLF. Finally, we also describe the transcriptomics in HBV-ACLF and the recent progress of single-cell RNA sequencing as well as its potential application in the study of ACLF in the future, in order to gain a deeper understanding of ACLF in terms of single-cell gene expression.

Advances in Immunotherapy for Hepatitis B

Hepatitis B virus (HBV) is a hepatotropic virus with the potential to cause chronic infection, and it is one of the common causes of liver disease worldwide. Chronic HBV infection leads to liver cirrhosis and, ultimately, hepatocellular carcinoma (HCC). The persistence of covalently closed circular DNA (cccDNA) and the impaired immune response in patients with chronic hepatitis B (CHB) has been studied over the past few decades. Despite advances in the etiology of HBV and the development of potent virus-suppressing regimens, a cure for HBV has not been found. Both the innate and adaptive branches of immunity contribute to viral eradication. However, immune exhaustion and evasion have been demonstrated during CHB infection, although our understanding of the mechanism is still evolving. Recently, the successful use of an antiviral drug for hepatitis C has greatly encouraged the search for a cure for hepatitis B, which likely requires an approach focused on improving the antiviral immune response. In this review, we discuss our current knowledge of the immunopathogenic mechanisms and immunobiology of HBV infection. In addition, we touch upon why the existing therapeutic approaches may not achieve the goal of a functional cure. We also propose how combinations of new drugs, and especially novel immunotherapies, contribute to HBV clearance.

Stem Cell Therapies for Chronic Liver Diseases: Progress and Challenges

Chronic liver diseases have become a significant health issue worldwide and urgently require the development of novel therapeutic approaches, in addition to liver transplantation. Recent clinical and preclinical studies have shown that cell-based therapeutic strategies may contribute to the improvement of chronic liver diseases and offer new therapeutic options to restore liver function through their roles in tissue impairment and immunomodulation. In this review, we summarize the current progress and analyze the challenges for different types of cell therapies used in the treatment of chronic liver diseases currently explored in clinical trials and preclinical studies in animal models. We also discuss some critical issues regarding the use of mesenchymal stem cells (MSCs, the most extensive cell source of stem cells), including therapeutic dosage, transfusion routine, and pharmacokinetics/pharmacodynamics (PK/PD) of transfused MSCs.

Therapeutic Benefits of Mesenchymal Stem Cells in Acute Respiratory Distress Syndrome: Potential Mechanisms and Challenges

Acute respiratory distress syndrome (ARDS) presents as a form of acute respiratory failure resulting from non-cardiogenic pulmonary edema due to excessive alveolocapillary permeability, which may be pulmonary or systemic in origin. In the last 3 years, the coronavirus disease 2019 pandemic has resulted in an increase in ARDS cases and highlighted the challenges associated with this syndrome, as well as the unacceptably high mortality rates and lack of effective treatments. Currently, clinical treatment remains primarily supportive, including mechanical ventilation and drug-based therapy. Mesenchymal stem cell (MSC) therapies are emerging as a promising intervention in patients with ARDS and have promising therapeutic effects and safety. The therapeutic mechanisms include modifying the immune response and assisting with tissue repair. This review provides an overview of the general properties of MSCs and outlines their role in mitigating lung injury and promoting tissue repair in ARDS. Finally, we summarize the current challenges in the study of translational MSC research and identify avenues by which the discipline may progress in the coming years.