The impact of recipient age on the effects of umbilical cord mesenchymal stem cells on HBV-related acute-on-chronic liver failure and liver cirrhosis

Mesenchymal stem cells biological and biotechnological advances: Implications for clinical applications

BACKGROUND

Mesenchymal stem cells (MSCs) are multipotent stem cells that are able to differentiate into multiple lineages including bone, cartilage, muscle and fat. They hold immunomodulatory properties and therapeutic ability to treat multiple diseases, including autoimmune and chronic degenerative diseases. In this article, we reviewed the different biological properties, applications and clinical trials of MSCs. Also, we discussed the basics of manufacturing conditions, quality control, and challenges facing MSCs in the clinical setting.

METHODS

Extensive review of the literature was conducted through the databases PubMed, Google Scholar, and Cochrane. Papers published since 2015 and covering the clinical applications and research of MSC therapy were considered. Furthermore, older papers were considered when referring to pioneering studies in the field.

RESULTS

The most widely studied stem cells in cell therapy and tissue repair are bone marrow-derived mesenchymal stem cells. Adipose tissue-derived stem cells became more common and to a lesser extent other stem cell sources e.g., foreskin derived MSCs. MSCs therapy were also studied in the setting of COVID-19 infections, ischemic strokes, autoimmune diseases, tumor development and graft rejection. Multiple obstacles, still face the standardization and optimization of MSC therapy such as the survival and the immunophenotype and the efficiency of transplanted cells. MSCs used in clinical settings displayed heterogeneity in their function despite their extraction from healthy donors and expression of similar surface markers.

CONCLUSION

Mesenchymal stem cells offer a rising therapeutic promise in various diseases. However, their potential use in clinical applications requires further investigation.

Mesenchymal stromal cells for improvement of cardiac function following acute myocardial infarction: a matter of timing

Acute myocardial infarction (AMI) is the leading cause of cardiovascular death and remains the most common cause of heart failure. Reopening of the occluded artery, i.e., reperfusion, is the only way to save the myocardium. However, the expected benefits of reducing infarct size are disappointing due to the reperfusion paradox, which also induces specific cell death. These ischemia-reperfusion (I/R) lesions can account for up to 50% of final infarct size, a major determinant for both mortality and the risk of heart failure (morbidity). In this review, we provide a detailed description of the cell death and inflammation mechanisms as features of I/R injury and cardioprotective strategies such as ischemic postconditioning as well as their underlying mechanisms. Due to their biological properties, the use of mesenchymal stromal/stem cells (MSCs) has been considered a potential therapeutic approach in AMI. Despite promising results and evidence of safety in preclinical studies using MSCs, the effects reported in clinical trials are not conclusive and even inconsistent. These discrepancies were attributed to many parameters such as donor age, in vitro culture, and storage time as well as injection time window after AMI, which alter MSC therapeutic properties. In the context of AMI, future directions will be to generate MSCs with enhanced properties to limit cell death in myocardial tissue and thereby reduce infarct size and improve the healing phase to increase postinfarct myocardial performance.

The Immunoregulatory and Regenerative Potential of Activated Human Stem Cell Secretome Mitigates Acute-on-Chronic Liver Failure in a Rat Model

Acute-on-chronic liver failure (ACLF) is a syndrome marked by sudden liver function decline and multiorgan failure, predominantly acute kidney injury (AKY), in patients with chronic liver disease. Unregulated inflammation is a hallmark of ACLF; however, the key drivers of ACLF are not fully understood. This study explores the therapeutic properties of human mesenchymal stem cell (MSC) secretome, particularly focusing on its enhanced anti-inflammatory and pro-regenerative properties after the in vitro preconditioning of the cells. We evaluated the efficacy of the systemic administration of MSC secretome in preventing liver failure and AKI in a rat ACLF model where chronic liver disease was induced using by the administration of porcine serum, followed by D-galN/LPS administration to induce acute failure. After ACLF induction, animals were treated with saline (ACLF group) or MSC-derived secretome (ACLF-secretome group). The study revealed that MSC-secretome administration strongly reduced liver histological damage in the ACLF group, which was correlated with higher hepatocyte proliferation, increased hepatic and systemic anti-inflammatory molecule levels, and reduced neutrophil and macrophage infiltration. Additionally, renal examination revealed that MSC-secretome treatment mitigated tubular injuries, reduced apoptosis, and downregulated injury markers. These improvements were linked to increased survival rates in the ACLF-secretome group, endorsing MSC secretomes as a promising therapy for multiorgan failure in ACLF.

Identifying optimal candidates for autologous peripheral blood stem cell therapy in patients with decompensated liver cirrhosis: a prognostic scoring system

BACKGROUND

Stem cell transplantation shows great potential to improve the long-term survival of cirrhosis patients. However, therapeutic effects may not be homogeneous across the whole study population. This study constructed an easy-to-use nomogram to improve prognostic prediction and aid in treatment decision making for cirrhotic patients.

METHODS

From August 2005 to April 2019, 315 patients with decompensated cirrhosis receiving autologous peripheral blood stem cell (PBSC) transplantation were enrolled in this study. They were randomly classified into training (2/3) and validation (1/3) groups. A predictive model was developed using Cox proportional hazard models and subsequently validated. The predictive performance of the model was evaluated and also compared with other prognostic models.

RESULTS

Age, creatinine, neutrophil-to-lymphocyte ratio, and Child-Turcotte-Pugh class were included in the nomogram as prognostic variables. The nomogram showed high discrimination power concerning the area under receiver operating characteristic curves (3/5-year AUC: 0.742/0.698) and good consistency suggested by calibration plots. Patients could be accurately stratified into poor- and good-outcome groups regarding liver-transplantation free survival after receiving PBSC therapy (P < 0.001). Compared with poor-outcome group, the liver function of patients listed for liver transplantation in the good-outcome group was significantly improved (P < 0.001). Besides, our nomogram achieved a higher C-index (0.685, 95% CI 0.633-0.738) and better clinical utility compared with other conventional prognostic models.

CONCLUSIONS

The proposed nomogram facilitated an accurate prognostic prediction for patients with decompensated cirrhosis receiving PBSC transplantation. Moreover, it also held the promise to stratify patients in clinical trials or practice to implement optimal treatment regimens for individuals.

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

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

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.

Mesenchymal Stem Cell Therapy in Acute Liver Failure

Acute liver failure (ALF) is a severe liver disease syndrome with rapid deterioration and high mortality. Liver transplantation is the most effective treatment, but the lack of donor livers and the high cost of transplantation limit its broad application. In recent years, there has been no breakthrough in the treatment of ALF, and the application of stem cells in the treatment of ALF is a crucial research field. Mesenchymal stem cells (MSCs) are widely used in disease treatment research due to their abundant sources, low immunogenicity, and no ethical restrictions. Although MSCs are effective for treating ALF, the application of MSCs to ALF needs to be further studied and optimized. In this review, we discuss the potential mechanisms of MSCs therapy for ALF, summarize some methods to enhance the efficacy of MSCs, and explore optimal approaches for MSC transplantation.

Relationship Between Platelets and the Clinical Efficacy of Umbilical Cord Mesenchymal Stem Cells for HBV-Related Acute-on-Chronic Liver Failure and Liver Cirrhosis: A Preliminary Clinical Study

BACKGROUND

Previous studies have found that the production of platelets could enhance the therapeutic effects of stem cells. Nevertheless, there are still no articles reporting on the relationship between platelets and the clinical efficacy of umbilical cord mesenchymal stem cells (UCMSCs) for HBV-related acute-on-chronic liver failure (ACLF) and liver cirrhosis (LC).

METHODS

In this retrospective observational study, patients who met the criteria were included. Patients were divided into subgroups according to the aims of this study. In the first part, the platelet count changes of ACLF and patients with LC after UCMSC therapy were compared and analyzed. Subgroup analysis based on UCMSC infusion times and patient age was also performed. In the second part, patients in the ACLF group and LC group were further divided into subgroups according to their platelet levels. Their clinical characteristics, demographics, and biochemical factors were compared.

RESULTS

This study enrolled 64 patients with ACLF and 59 patients with LC. In both groups, platelet levels declined similarly. Compared with the short-course UCMSC treatment group (≤4 times), patients with ACLF and patients with LC with long-course UCMSC treatment (>4 times) showed an overall increasing trend. Younger patients with LC (<45 years) had significantly higher platelet levels than older patients with LC (≥45 years). However, this age difference was not present in the ACLF group. The median TBIL decrease and cumulative TBIL decrease were not significantly different between patients with high PLT and patients with low PLT after UCMSC transfusions. For patients with ACLF, the cumulative TBIL decrease and the median TBIL decrease were significantly greater than those of patients with LC at the same platelet level after UCMSC treatment. However, this difference was not observed at all time points.

CONCLUSION

Trend of the platelet levels for HBV-related patients with ACLF and LC after UCMSC treatment did not parallel and varied according to treatment times and patients' age. Platelet levels did not affect the efficacy of MSCs for patients with ACLF or LC.

Mesenchymal stem cells-based therapy in liver diseases

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

The assessment of mesenchymal stem cells therapy in acute on chronic liver failure and chronic liver disease: a systematic review and meta-analysis of randomized controlled clinical trials

Background

Mesenchymal stem cells (MSCs) therapy is showing potential therapeutic effects on liver function improvement in patients with chronic liver disease; however, the consensus on efficacy and safety of MSCs has not been reached.

Methods

We performed this systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy and safety of MSCs therapy for patients with chronic liver disease. A detailed search of the Cochrane Library, MEDLINE, Web of Science, and EMBASE databases was conducted to find studies published prior to September 15, 2021. The outcome measures were survival rate, model of end-stage liver disease (MELD) score, albumin, total bilirubin, coagulation function, and aminotransferase.

Results

A literature search resulted in 892 citations. Of these, 12 studies met the inclusion criteria. It was found that compared with conventional treatment, MSCs therapy was associated with improved liver function including the MELD score, albumin levels, and coagulation function. However, it had no obvious beneficial effects on survival rate and aminotransferase levels. Subgroup analyses indicated that MSCs therapy had therapeutic effects on patients with both acute on chronic liver failure (ACLF) and cirrhosis. BM-MSCs and UC-MSCs treatment had similar efficacy to improve liver function. The effectiveness varied slightly between the peripheral intravenous injection and hepatic arterial injection. Five studies reported that the only adverse event of the MSCs therapy was fever, and no serious adverse events and side effects were reported. Analysis on clinical symptoms showed that encephalopathy and gastrointestinal hemorrhage events were reduced after MSCs therapy.

Conclusions

In conclusion, this study suggested that MSCs therapy could be a potential therapeutic alternative for patients with chronic liver disease in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02882-4.

Extraembryonic Mesenchymal Stromal/Stem Cells in Liver Diseases: A Critical Revision of Promising Advanced Therapy Medicinal Products

Liver disorders have been increasing globally in recent years. These diseases are associated with high morbidity and mortality rates and impose high care costs on the health system. Acute liver failure, chronic and congenital liver diseases, as well as hepatocellular carcinoma have been limitedly treated by whole organ transplantation so far. But novel treatments for liver disorders using cell-based approaches have emerged in recent years. Extra-embryonic tissues, including umbilical cord, amnion membrane, and chorion plate, contain multipotent stem cells. The pre-sent manuscript discusses potential application of extraembryonic mesenchymal stromal/stem cells, focusing on the management of liver diseases. Extra-embryonic MSC are characterized by robust and constitutive anti-inflammatory and anti-fibrotic properties, indicating as therapeutic agents for inflammatory conditions such as liver fibrosis or advanced cirrhosis, as well as chronic inflammatory settings or deranged immune responses.