Liver Transplantation Update: 2014

Mesenchymal Stem Cells Alleviate Acute Liver Failure through Regulating Hepatocyte Apoptosis and Macrophage Polarization

Background and Aims

Acute liver failure (ALF) is a life-threatening clinical problem with limited treatment options. Administration of human umbilical cord mesenchymal stem cells (hUC-MSCs) may be a promising approach for ALF. This study aimed to explore the role of hUC-MSCs in the treatment of ALF and the underlying mechanisms.

Methods

A mouse model of ALF was induced by lipopolysaccharide and d-galactosamine administration. The therapeutic effects of hUC-MSCs were evaluated by assessing serum enzyme activity, histological appearance, and cell apoptosis in liver tissues. The apoptosis rate was analyzed in AML12 cells. The levels of inflammatory cytokines and the phenotype of RAW264.7 cells co-cultured with hUC-MSCs were detected. The C-Jun N-terminal kinase/nuclear factor-kappa B signaling pathway was studied.

Results

The hUC-MSCs treatment decreased the levels of serum alanine aminotransferase and aspartate aminotransferase, reduced pathological damage, alleviated hepatocyte apoptosis, and reduced mortality in vivo. The hUC-MSCs co-culture reduced the apoptosis rate of AML12 cells in vitro. Moreover, lipopolysaccharide-stimulated RAW264.7 cells had higher levels of tumor necrosis factor-α, interleukin-6, and interleukin-1β and showed more CD86-positive cells, whereas the hUC-MSCs co-culture reduced the levels of the three inflammatory cytokines and increased the ratio of CD206-positive cells. The hUC-MSCs treatment inhibited the activation of phosphorylated (p)-C-Jun N-terminal kinase and p-nuclear factor-kappa B not only in liver tissues but also in AML12 and RAW264.7 cells co-cultured with hUC-MSCs.

Conclusions

hUC-MSCs could alleviate ALF by regulating hepatocyte apoptosis and macrophage polarization, thus hUC-MSC-based cell therapy may be an alternative option for patients with ALF.

Upregulation of microRNA-125b-5p alleviates acute liver failure by regulating the Keap1/Nrf2/HO-1 pathway

Background

Acute liver failure (ALF) and acute-on-chronic liver failure (ACLF) are the two most common subtypes of liver failure. They are both life-threatening clinical problems with high short-term mortality. Although liver transplantation is an effective therapeutic, its application is limited due to the shortage of donor organs. Given that both ACLF and ALF are driven by excessive inflammation in the initial stage, molecules targeting inflammation may benefit the two conditions. MicroRNAs (miRNAs) are a group of small endogenous noncoding interfering RNA molecules. Regulation of miRNAs related to inflammation may serve as promising interventions for the treatment of liver failure.

Aims

To explore the role and mechanism of miR-125b-5p in the development of liver failure.

Methods

Six human liver tissues were categorized into HBV-non-ACLF and HBV-ACLF groups. Differentially expressed miRNAs (DE-miRNAs) were screened and identified through high-throughput sequencing analysis. Among these DE-miRNAs, miR-125b-5p was selected for further study of its role and mechanism in lipopolysaccharide (LPS)/D-galactosamine (D-GalN) -challenged Huh7 cells and mice in vitro and in vivo.

Results

A total of 75 DE-miRNAs were obtained. Of these DE-miRNAs, miR-125b-5p was the focus of further investigation based on our previous findings and preliminary results. We preliminarily observed that the levels of miR-125b-5p were lower in the HBV-ACLF group than in the HBV-non-ACLF group. Meanwhile, LPS/D-GalN-challenged mice and Huh7 cells both showed decreased miR-125b-5p levels when compared to their untreated control group, suggesting that miR-125b-5p may have a protective role against liver injury, regardless of ACLF or ALF. Subsequent results revealed that miR-125b-5p not only inhibited Huh7 cell apoptosis in vitro but also relieved mouse ALF in vivo with evidence of improved liver histology, decreased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, and reduced tumor necrosis factor-α (TNF-α) and IL-1β levels. Based on the results of a biological prediction website, microRNA.org, Kelch-like ECH-associated protein 1 (Keap1) was predicted to be one of the target genes of miR-125b-5p, which was verified by a dual-luciferase reporter gene assay. Western blot results in vitro and in vivo showed that miR-125b-5p could decrease the expression of Keap1 and cleaved caspase-3 while upregulating the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase-1(HO-1).

Conclusion

Upregulation of miR-125b-5p can alleviate acute liver failure by regulating the Keap1/Nrf2/HO-1 pathway, and regulation of miR-125b-5p may serve as an alternative intervention for liver failure.

Stem cell therapy in liver regeneration: Focus on mesenchymal stem cells and induced pluripotent stem cells

The liver has the ability to repair itself after injury; however, a variety of pathological changes in the liver can affect its ability to regenerate, and this could lead to liver failure. Mesenchymal stem cells (MSCs) are considered a good source of cells for regenerative medicine, as they regulate liver regeneration through different mechanisms, and their efficacy has been demonstrated by many animal experiments and clinical studies. Induced pluripotent stem cells, another good source of MSCs, have also made great progress in the establishment of organoids, such as liver disease models, and in drug screening. Owing to the recent developments in MSCs and induced pluripotent stem cells, combined with emerging technologies including graphene, nano-biomaterials, and gene editing, precision medicine and individualized clinical treatment may be realized in the near future.

Safety Evaluation of Human Cord-Lining Epithelial Stem Cells Transplantation for Liver Regeneration in a Porcine Model

We investigated the safety of using umbilical cord-lining stem cells for liver regeneration and tested a novel method for stem cell delivery. Stem cells are known by their ability to repair damaged tissues and have the potential to be used as regenerative therapies. The umbilical cord's outer lining membrane is known to be a promising source of multipotent stem cells and can be cultivated in an epithelial cell growth medium to produce cell populations which possess the properties of both epithelial cells and embryonic stem cells-termed cord-lining epithelial cells (CLEC). Hepatocytes are epithelial cells of the liver and their proliferation upon injury is the main mechanism in restoring the liver. Earlier studies conducted showed CLEC can be differentiated into functioning hepatocyte-like cells (HLC) and can survive in immunologically competent specimens. In this study, we chose a porcine model to investigate CLEC as a treatment modality for liver failure. We selected 16 immune competent Yorkshire-Dutch Landrace pigs, with a mean weight of 40.5 kg, for this study. We performed a 50% hepatectomy to simulate the liver insufficient disease model. After the surgery, four pigs were transplanted with a saline scaffold while seven pigs were transplanted with a HLC scaffold. Five pigs died on the surgical table and were omitted from the study analysis. This study addressed the safety of transplanting human CLEC in a large animal model. The transplant interfaces were evaluated and no signs of cellular rejection were observed in both groups.

Updates on the Diagnosis and Management of Hepatocellular Carcinoma

Introduction

Globally, the incidence, as well as mortality, related to hepatocellular carcinoma (HCC) is on the rise, owing to relatively few curative options. Underlying cirrhosis is the most common etiology leading to HCC, but risk factors of cirrhosis show great regional variability. Over the years, there has been a steady development in the diagnostic and therapeutic modalities of HCC, including the availability of a wide range of systemic chemotherapeutic agents. We aim to review the recent advancements in the diagnostic and therapeutic strategies for HCC.

Methodology

The literature search was done using databases PubMed, Cochrane, and Science Direct, and the latest relevant articles were reviewed.

Findings

Screening of HCC is a pivotal step in the early diagnosis of the disease. Current guidelines recommend using ultrasound and alfa fetoprotein but various new biomarkers are under active research that might aid in diagnosing very small tumors, not picked up by the current screening methods. Treatment options are decided based upon the overall performance of the patient and the extent of the disease, as per the Barcelona classification. There are very few options that offer a cure for the disease, ranging from liver resection and transplantation to tumor ablation. Downstaging has proven to have a significant role in the course of the disease. An attempt to control the disease can be made via radiological interventions, such as transarterial chemoembolization, transarterial radioembolization, or radiation therapy. For advanced disease, sorafenib used to be the only option until a couple of years ago. Recently, many other systemic agents have received approval as first-line and second-line therapies for HCC. Genomics is an area of active clinical research as understanding the mutations and genomics involved in the evolution of HCC might lead to a breakthrough therapy.

How to cite this article

Raees A, Kamran M, Özkan H, et al. Updates on the Diagnosis and Management of Hepatocellular Carcinoma. Euroasian J Hepato-Gastroenterol 2021;11(1):32–40.

Psychosocial Outcomes of Donors Whose Recipients Died After Living Donor Liver Transplantation

PURPOSE

Our aim was to investigate the psychosocial outcomes of the donors whose recipients died after living donor liver transplantation (LDLT).

METHODS

Forty-one donors whose recipients died and 87 donors whose recipients were alive after LDLT at Inonu University Liver Transplantation Institute between 2012 and 2017 were included into the study. Demographic data form, Beck anxiety scale, Beck depression scale, Beck Hopelessness Scale, Posttraumatic Growth Inventory, Decision Regret Scale, Multidimensional Scale of Perceived Social Support, and general evaluation questionnaire (24 questions) were used in all donors by face to face questioning. In addition to the descriptive statistical analysis, chi-square and student's t tests were used to evaluate the differences between the groups.

RESULTS

Recipient death after living donor liver transplantation is a factor that negatively increases the level of anxiety, depression, hopelessness levels, and repentance of donors, and adversely affects the psychological growth of the donors after donation experience.

CONCLUSION

Regular follow-up of the donors should be done psychosocially in the postoperative period, especially the donors whose recipients have died should be followed up more frequently, and their support and treatment should be provided when needed. The donors should also be informed about the psychosocial implications of operative management and postoperative period. More studies are needed regarding the psychosocial problems of the donors.

The role of multislice computerized tomography angiography in assessing postoperative vascular complications in liver transplant patients

Background/aim

Vascular complications can be detected in liver transplant patients. Digital subtraction angiography has served as the gold standard to make this diagnosis; however, due to its invasive nature, ultrasonography is used for the preliminary evaluation. The purpose of this study was to evaluate the role of multislice computerized tomography angiography (MSCTA) in the detection of vascular complications of symptomatic and asymptomatic liver transplant patients and to compare the results with Doppler ultrasound (Doppler US) findings.

Materials and methods

Fifty-three liver transplant patients (6 symptomatic, 47 asymptomatic) underwent Doppler US examination followed by an MSCTA. The findings in each modality were interpreted in a blinded fashion and then compared.

Results

MSCTA detected 15 abnormalities, none of which were detected by Doppler US. There were hepatic and splenic artery aneurysms (n = 4) and various stenoses (n = 4), infrarenal aortic anastomosis (n = 4), vena cava inferior thrombosis (n = 1), arteriovenous malformation (n = 1), and esophageal varices (n = 1).

Conclusion

MSCTA detected more lesions and we believe that it should be considered as a road map for Doppler US follow-ups as well as a routine screening modality for early detection of vascular complications in symptomatic and asymptomatic liver transplantation patients that may be missed by Doppler US.

Reappraisal of Failures in Downstaging Treatment of Hepatocellular Carcinoma Prior to Liver Transplant-Preliminary Report on the Impact of Underestimations of Tumor Numbers and Tumor Sizes as Measured From Imaging Before Transplant

Downstaging treatment of hepatocellular carcinoma (HCC) prior to liver transplant (LT) is an accepted strategy to meet the Milan criteria. However, after transplant surgery, a reality is noted that the number or/and the size of some HCCs measured from the liver explants is different from that measured from the pre-LT imaging. If tumor number or tumor size measured from the liver explants was beyond that measured from pre-LT imaging, we define it as "failed downstaging." Among 27 patients who received downstaging therapies, there are 11 "number reduction failures" and 6 "size reduction failures." We attribute the discrepancy to 2 possible reasons; one is that the pre-LT imaging after downstaging could not completely detect all the HCC; the other is that the time interval between the downstaging and LT is long enough to develop new HCCs. After follow-up, 6 patients developed HCC recurrence. The significant factors affecting recurrence include tumor size from postdownstaging imaging (P = .048), tumor number ≥ 2 (P = .007), multiple sessions of downstaging (P = .03), ratio of neutrophil to lymphocyte (P = .047), and tumor number from liver explant (borderline P = .05). Tumor recurrence after LT is significantly higher in those with "size reduction failure" (P = .048). The interval between LT and tumor recurrence is significantly shorter in those with "size reduction failure" (P = .04). To decrease underestimations of HCC, combining various imaging studies including the computed tomographic scan, magnetic resonance imaging, and contrast ultrasonography is needed to increase the accuracy before LT. Repeated imaging studies at short intervals of no more than 3 months are necessary during a long wait. How to minimize the underestimations of HCC to determine the appropriate candidacy for LT is an important goal for transplantation surgeons.