Liver transplantatation- an overview

AI Innovations in Liver Transplantation: From Big Data to Better Outcomes

Artificial intelligence (AI) has emerged as a transformative field in computational research with diverse applications in medicine, particularly in the field of liver transplantation (LT) given its ability to analyze and build upon complex and multidimensional data. This literature review investigates the application of AI in LT, focusing on its role in pre-implantation biopsy evaluation, development of recipient prognosis algorithms, imaging analysis, and decision-making support systems, with the findings revealing that AI can be applied across a variety of fields within LT, including diagnosis, organ allocation, and surgery planning. As a result, algorithms are being developed to assess steatosis in pre-implantation biopsies and predict liver graft function, with AI applications displaying great accuracy across various studies included in this review. Despite its relatively recent introduction to transplantation, AI demonstrates potential in delivering cost and time-efficient outcomes. However, these tools cannot replace the role of healthcare professionals, with their widespread adoption demanding thorough clinical testing and oversight.

A Study on iPSC-Associated Factors in the Generation of Hepatocytes

BACKGROUND

Hepatocytes are an attractive cell source in hepatic tissue engineering because they are the primary cells of the liver, maintaining liver homeostasis through their intrinsic function. Due to the increasing demand for liver donors, a wide range of methods are being studied to obtain functionally active hepatocytes. iPSCs are one of the alternative cell sources, which shows great promise as a tool for generating hepatocytes.

METHODS

This study determined whether factors associated with iPSCs contributed to variation in hepatocyte-like cells derived from iPSCs. The factors of concern for the iPSCs included the culture system, the source of iPSCs, and cell seeding density for initiating the differentiation.

RESULTS

Our results found iPSC-dependent variances among differentiated hepatocyte-like cells. The matrix used in culturing iPSCs significantly impacts cell morphologies, characteristics, and the expression of pluripotent genes, such as OCT4 and SOX2, varied in iPSCs derived from different sources. These characteristics, in turn, play a consequential role in determining the functional activity of the iPSC-derived hepatocyte-like cells. In addition, cell seeding density was observed to be an essential factor for the efficient generation of iPSC-derived hepatocyte-like cells, with 2- 4 × 10 cells/cm of seeding density resulting in good morphology and functionality.

CONCLUSION

This study provides the baseline of effective differentiation protocols for iPSC-derived hepatocyte-like cells with the appropriate conditions, including cell culture media, iPSC source, and the seeding density of iPSCs.

Cognitive impairment in patients awaiting kidney and liver transplantation-A clinically relevant problem?

INTRODUCTION

Cognitive impairment (CI) is common in both end-stage kidney disease (ESKD) and alcohol-related liver cirrhosis. The aim of this study was to assess the prevalence and patterns of CI in patients awaiting kidney and liver transplantation, and to identify its determinants.

METHODS

In this cross-sectional, prospective study, 31 consecutive patients with ESKD and 31 consecutive patients with alcohol-related liver cirrhosis, all currently on transplant waiting lists, were screened for cognitive decline using the Addenbrooke's Cognitive Examination. Medical history, demographics, and laboratory test results were also collected.

RESULTS

The prevalence of CI among patients with ESKD and alcohol-related liver cirrhosis was 26% and 90%, respectively. In both groups, memory was the most affected cognitive domain, along with verbal fluency in patients with ESKD, and visuospatial abilities in patients with alcoholic cirrhosis. The most statistically significant increase in the prevalence of CI was found in patients with lower educational attainment, in both alcohol-related liver cirrhosis and ESKD populations as well as in older patients with alcoholic cirrhosis. Furthermore, better cognitive functioning in ESKD patients was associated with higher levels of total lymphocyte count and alanine transaminase (ALT), and in alcohol-related liver cirrhosis patients with higher levels of ALT and aspartate transaminase. A nonsignificant trend toward lower memory domain scores was also observed with increasing ammonia levels and increasing severity of liver disease (higher Child-Pugh scores). Finally, suboptimal performance on the screening test was correlated with the severity of liver disease as assessed by the Model for End-Stage Liver Disease Sodium (MELD-Na), but not at the statistically significant level.

CONCLUSIONS

The prevalence of CI, especially in patients with alcohol-related liver cirrhosis, is high and can be a significant clinical problem, negatively affecting the transplantation process. Routine screening tests in this group would contribute to the implementation of appropriate management, such as rehabilitation program or psychosocial treatments and facilitate the provision of specialized health care.

Improving Patient Safety in Medication Management by Medication Reconciliation and Pharmaceutical Care Process in Post-Liver Transplant Clinic

INTRODUCTION

Liver transplant recipients receive many medications for anti-rejection, infection prophylaxis, and treatment of comorbidities. Most of them also receive medications from multiple sources. Therefore, these patients are prone to drug-related problems (DRPs) and medication errors. This study aimed to study the effect of medication reconciliation (MR) and pharmaceutical care processes by transplant pharmacists in the post-liver transplant clinic.

METHODS

This study was a retrospective study in Siriraj Liver Transplant Center, Mahidol University, Thailand. Patients who received pharmaceutical care from transplant pharmacists were compared before and after the implementation of MR (October 2020-September 2021 vs October 2021-September 2022) to assess the prevalence of medication errors and identify DRPs between the 2 groups.

RESULTS

Before implementation of MR, in a total of 797 visits, 69 medication errors (8.7%) were found. The most errors were medication omissions (44.9%, n = 31). After the implementation of MR, in a total of 879 visits, 44 medication errors (5.0%) were found. Most were medication omission and incorrect strength (31.8%, n = 14). Medication errors significantly decreased by 36.2% (P < .001) after the implementation of MR. Regarding DRPs, transplant pharmacists could significantly detect more DRPs after implementation of MR, 66 DRPs before implementation of MR vs 111 DRPs after implementation of MR (P < .001). The most DRPs were non-adherence (34 vs 41).

CONCLUSIONS

MR can reduce medication errors and assist transplant pharmacists in identifying DRPs that will lead to active intervention by attending physicians and/or patients to improve medication management and patient safety in post-liver transplant care.

Immunologic barriers in liver transplantation: a single-cell analysis of the role of mesenchymal stem cells

Background

This study aimed to analyze the biomarkers that may reliably indicate rejection or tolerance and the mechanism that underlie the induction and maintenance of liver transplantation (LT) tolerance related to immunosuppressant or mesenchymal stem cells (MSCs).

Methods

LT models of Lewis-Lewis and F344-Lewis rats were established. Lewis-Lewis rats model served as a control (Syn). F344-Lewis rats were treated with immunosuppressant alone (Allo+IS) or in combination with MSCs (Allo+IS+MSCs). Intrahepatic cell composition particularly immune cells was compared between the groups by single-cell sequencing. Analysis of subclusters, KEGG pathway analysis, and pseudotime trajectory analysis were performed to explore the potential immunoregulatory mechanisms of immunosuppressant alone or combined with MSCs.

Results

Immunosuppressants alone or combined with MSCs increases the liver tolerance, to a certain extent. Single-cell sequencing identified intrahepatic cell composition signature, including cell subpopulations of B cells, cholangiocytes, endothelial cells, erythrocytes, hepatic stellate cells, hepatocytes, mononuclear phagocytes, neutrophils, T cells, and plasmacytoid dendritic cells. Immunosuppressant particularly its combination with MSCs altered the landscape of intrahepatic cells in transplanted livers, as well as gene expression patterns in immune cells. MSCs may be included in the differentiation of T cells, classical monocytes, and non-classical monocytes.

Conclusion

These findings provided novel insights for better understanding the heterogeneity and biological functions of intrahepatic immune cells after LT treated by IS alone or in combination with MSCs. The identified markers of immune cells may serve as the immunotherapeutic targets for MSC treatment of liver transplant rejection.

Hepatocellular Carcinoma: Surveillance, Diagnosis, Evaluation and Management

Hepatocellular carcinoma (HCC) ranks fourth in cancer-related deaths worldwide. Semiannual surveillance of the disease for patients with cirrhosis or hepatitis B virus allows for early detection with more favorable outcomes. The current underuse of surveillance programs demonstrates the need for intervention at both the patient and provider level. Mail outreach along with navigation provision has proven to increase surveillance follow-up in patients, while provider-targeted electronic medical record reminders and compliance reports have increased provider awareness of HCC surveillance. Imaging is the primary mode of diagnosis in HCC with The Liver Imaging Reporting and Data System (LI-RADS) being a widely accepted comprehensive system that standardizes the reporting and data collection for HCC. The management of HCC is complex and requires multidisciplinary team evaluation of each patient based on their preference, the state of the disease, and the available medical and surgical interventions. Staging systems are useful in determining the appropriate intervention for HCC. Early-stage HCC is best managed by curative treatment modalities, such as liver resection, transplant, or ablation. For intermediate stages of the disease, transarterial local regional therapies can be applied. Advanced stages of the disease are treated with systemic therapies, for which there have been recent advances with new drug combinations. Previously sorafenib was the mainstay systemic treatment, but the recent introduction of atezolizumab plus bevacizumab proves to have a greater impact on overall survival. Although there is a current lack of improved outcomes in Phase III trials, neoadjuvant therapies are a potential avenue for HCC management in the future.

PREDICTIVE BIOMARKERS OF LIVING DONOR LIVER TRANSPLANTATION

Objective: Liver transplantation using a living donor (LDLT) is currently the most popular method used in the worldwide. Appropriate biomarkers that predict graft status should be used to detect early post-transplant complications that may lead to a rejection reaction. Material and Method: The study involved a total of 44 liver recipients and 44 liver donors, from whom preoperative blood samples were taken and immunoassay and spectrophotometric studies were carried out. The levels of serum neopterin, interferon-gamma (IFN- y), indoleamine-2,3 dioxygenase (IDO), and -glutathione S transferase (a-GST) were assessed using an enzyme-linked immunosorbent test. The activity of glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PD) in erythrocytes was measured using spectrophotometry. Result and Discussion: “Neopterin, IDO, and G6PD levels were significantly higher in the recipient group than in the donor group. The differences in gender and blood groups were statistically insignificant. The rejection reaction developed in 25% of patients and none survived. These findings may facilitate the identification of novel predictive biomarkers for the diagnosis of acute rejection reactions after LDLT. The clinical use of novel non-invasive biomarkers may provide time and cost advantages.

Experimental Demonstration of Compact Polymer Mass Transfer Device Manufactured by Additive Manufacturing with Hydrogel Integration to Bio-Mimic the Liver Functions

In this paper, we designed and demonstrated a stimuli-responsive hydrogel that mimics the mass diffusion function of the liver. We have controlled the release mechanism using temperature and pH variations. Additive manufacturing technology was used to fabricate the device with nylon (PA-12), using selective laser sintering (SLS). The device has two compartment sections: the lower section handles the thermal management, and feeds temperature-regulated water into the mass transfer section of the upper compartment. The upper chamber has a two-layered serpentine concentric tube; the inner tube carries the temperature-regulated water to the hydrogel using the given pores. Here, the hydrogel is present in order to facilitate the release of the loaded methylene blue (MB) into the fluid. By adjusting the fluid’s pH, flow rate, and temperature, the deswelling properties of the hydrogel were examined. The weight of the hydrogel was maximum at 10 mL/min and decreased by 25.29% to 10.12 g for the flow rate of 50 mL/min. The cumulative MB release at 30 °C increased to 47% for the lower flow rate of 10 mL/min, and the cumulative release at 40 °C climbed to 55%, which is 44.7% more than at 30 °C. The MB release rates considerably increased when the pH dropped from 12 to 8, showing that the lower pH had a major impact on the release of MB from the hydrogel. Only 19% of the MB was released at pH 12 after 50 min, and after that, the release rate remained nearly constant. At higher fluid temperatures, the hydrogels lost approximately 80% of their water in just 20 min, compared to a loss of 50% of their water at room temperature. The outcomes of this study may contribute to further developments in artificial organ design.

Invasive Fungal Infections After Liver Transplantation: A Retrospective Matched Controlled Risk Analysis

Background

Invasive fungal infections (IFI) are major risks for mortality after liver transplantation (LT). The aim of this study was to evaluate possible risk factors for the development of IFI after LT.

Material/Methods

All adult patients with IFI after LT between January 2012 and December 2016 at Essen University were identified. Pre-, intra-, and postoperative data were reviewed. These were compared to a 1-to-3 matched control group. Multinominal univariate and multivariate regression analyses were performed.

Results

Out of the 579 adults who underwent LT, 33 (5.6%) developed postoperative IFI. Fourteen had invasive aspergillosis with 7 (50%) mortality, and 19 had Candida sepsis with 7 (37%) mortality. The overall mortality due to invasive fungal infections was 42%. Perfusion fluid contamination with yeast was detected in 5 patients (15%). Multivariate regression analyses showed that preoperative dialysis (OR=1.163; CI: 1.038–1.302), Eurotransplant donor risk index (OR=0.04; CI=0.003–0.519), length of hospital stay (OR=25.074; CI: 23.99–26.208), and yeast contamination of the preservation fluid (OR=47.8; CI: 4.77–478, 96) were associated with IFI in the Candida group, whereas duration of surgery (OR=1.013; CI: 1.005–1.022), ventilation hours (OR=0.993; CI=0.986–0.999), and days of postoperative dialysis (OR=1.195; CI: 1.048–1,362) were associated with IFI in the aspergillosis group.

Conclusions

Post-LT IFI had 42% mortality in our cohort. Prophylactic antifungal therapy should be expanded to broader risk groups as defined above.

Quality of life 5 years following liver transplantation

BACKGROUND

Data on quality of life (QOL) among liver transplant recipients from India is scarce. We conducted a prospective assessment of QOL and incidence of complications 5 years following liver transplantation (LT).

METHODS

Demographic data of 130 patients (M:F = 98:32, mean age 38.4 ± 14.9 years) who had completed at least 5 years after LT were collected and the incidence of new onset metabolic complications and renal dysfunction was analyzed. Liver transplant database (LTD QOL) questionnaire was given to 100 patients and scoring was done on five QOL domains. This was compared to a historical cohort from the liver transplant database of three transplant centres from North America, who had completed the same questionnaire before and 1 year after LT.

RESULTS

The incidence of new onset dyslipidemia, diabetes mellitus, renal dysfunction, hypertension and overweight/obesity was 43%, 26.7%, 25%, 16.4% and 15.4%, respectively. Although ethanol-related cirrhosis was the etiology for transplant in 38%, recidivism was not evident in any recipient in this cohort even after 5 years. Significant improvement in QOL was observed in all five domains, namely measures of disease (p=0.001), psychological status (p=0.001), personal function (p=0.001), social and role function (p=0.001) and general health perception (p=0.001) in our patients 5 years after transplant compared to historical data.

CONCLUSION

Although metabolic disease is common after LT, there is significant improvement in long-term QOL. Recidivism appeared to be rare in our study population.

Epidemiological characteristics of de novo hepatitis B infection in liver transplant recipients-An experience from a tertiary care centre in Qatar

BACKGROUND

The emergence of hepatitis B surface antigen in a patient with previously negative hepatitis B virus (HBV) serology post-orthotropic liver transplant (OTLX) is known as de novo hepatitis B (DNHB). As there are no data on patients with DNHB available from Qatar, we aim to do a pioneer study indexing their clinical profile and epidemiology of patients with DNHB in Qatar.

MATERIALS AND METHODS

This descriptive epidemiological study was done by retrospectively reviewing records of 159 post-OTLX patients. HBV serology of these patients post-OTLX was reviewed, and 17 were identified as DNHB cases. Baseline epidemiological characteristics were defined and compared between DNHB cases and the rest. DNHB cases were analyzed statistically using the chi-square test and Kaplan-Meier curve.

RESULTS

The majority of the subjects were men (65%) and Qataris (40%). Mean age was 57.4 ± 12.5 years. Bulk of them underwent OTLX in China (44%). The overall incidence of DNHB was 10.7%, with transplants in China having significantly higher incidence than transplants from all other countries. The mortality rate was 23.5% in DNHB cases compared to 2.8% in non-DNHB. 67% of patients survived at least 64 months after the diagnosis of DNHB. Five-year survival did not vary significantly between those with DNHB and those without.

CONCLUSION

Orthotropic liver transplant in centers selecting donors liberally without screening for HBV poses the risk of DNHB. We recommend having protective levels of HBs antibodies before OTLX. Prophylactic antiviral treatment should be considered until peri-operative HBV transmission has been excluded by screening hepatic tissue for HBV DNA.

Effect of Hypotensive Brain Death on the Donor Liver and Its Mechanism in an Improved Bama Miniature Pig (Sus scrofa domestica) Model

BACKGROUND

We aimed to observe the effect of hypotensive brain death on the donor liver and understand its pathophysiological mechanism in improved pig model.

METHODS

The model was induced using the modified intracranial water sac inflation method in 16 Bama miniature pigs. Effects of hypotensive brain death on liver function and tissue morphology were evaluated via changes in liver function enzyme index, liver tissue alkaline phosphatase levels, hourly bile flow, and liver tissue pathology. Its pathophysiological mechanism was examined on the basis of changes in portal vein blood flow, hepatic artery blood flow, portal venous endotoxin level, and liver tissue cytokine levels.

RESULTS

After model establishment, portal vein blood flow, hepatic arterial blood flow, hourly bile flow, and alkaline phosphatase content in hepatic tissue significantly decreased, and serum aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase levels significantly increased. Hematoxylin-eosin staining of liver tissue showed that after model establishment, hepatic tissue injury was gradually aggravated and hepatic cells were irreversibly damaged at 7 hours. Portal vein endotoxin levels significantly increased after brain death. Tumor necrosis factor α, interleukin 1, and endothelin 1 levels in liver tissues significantly increased at 3, 6, and 12 hours after brain death (P < .05), and hypoxia-inducible factor 1-α and nitric oxide levels significantly decreased (P < .05).

CONCLUSIONS

Hepatic injury was progressively aggravated under hypotensive brain death. The mechanism of donor liver injury under hypotensive brain death may involve low liver perfusion, release of intestinal endotoxin and inflammatory factors (eg, tumor necrosis factor α and interleukin 1), decreased hypoxia-inducible factor 1-α, and endothelin 1 and nitric oxide imbalance.

Domino Hepatocyte Transplantation: A Therapeutic Alternative for the Treatment of Acute Liver Failure

BACKGROUND AND AIMS

Acute liver failure (ALF) is a severe syndrome with an elevated mortality rate, ranging from 40 to 80 %. Currently, liver transplantation is the only definitive treatment for these patients and new therapies aiming to treat ALF include artificial organs implant and stem cells therapy, for example. However, a major limitation of liver donors exists. Living donor liver transplantation (LDLT), split liver transplantation (SLT), and domino liver transplantation (DLT) are some of the available alternatives to treat ALF patients, but these do not reduce the number of patients on waiting lists. Herein, we discuss domino hepatocyte transplantation (DHT) using livers that would not meet transplantation criteria.

METHODS

We conducted a literature search on PubMed/Medline using acute liver failure, liver transplantation, hepatocyte transplantation, and domino liver transplantation as key words.

RESULTS

New sources of biochemically functional hepatocytes and therapeutic treatments, in parallel to organ transplantation, may improve liver injury recovery and decrease mortality rates. Moreover, the literature reports hepatocyte transplantation as a therapeutic alternative for organ shortage. However, a major challenge remains for a wide clinical application of hepatocytes therapy, i.e., the availability of sufficient amounts of cells for transplantation. Ideally, hepatocytes isolated from livers rejected for transplantation may be a promising alternative for this problem.

CONCLUSION

Our review suggests that DHT may be an excellent strategy to increase cell supplies for hepatocyte transplantation.

Anesthesia Management of Modified Ex Vivo Liver Resection and Autotransplantation

Background

Ex situ liver surgery allows liver resection and vascular reconstruction in patients who have liver tumors located in critical sites. Only a small series of studies about ex situ liver surgery is available in the literature. No anesthesia management experience has been previously published. The aim of the currents study was to summarize our experience with anesthetic management of patients during ex vivo liver surgery.

Material/Methods

The first 43 patients who received ex vivo liver surgery between January 2007 and April 2012 were included. A pulmonary artery catheter (PAC), transesophageal echocardiography (TEE), and pulse indicator continuous cardiac output (PiCCO) were used intraoperatively in the patients to monitor the hemodynamic changes. Thromboelastogram and the plasma coagulation test were used to monitor the coagulation changes.

Results

All patients received general anesthesia with rapid sequence induction. The data obtained by PAC, TEE, and PiCOO in these cases showed large changes in hemodynamics during the stages of the first or second vessel reconstruction. The CI decreased about 59%/63% and the MPAP decreased about 49%/37% during the first/second vessel reconstruction. Accurate judgment of the dosage of active drug for vascular support is the key for the stabilization of hemodynamics as quickly as possible. However, a high incidence (35.5%) of prophase fibrinolysis in a long anhepatic phase should be monitored and managed.

Conclusions

Ex vivo liver surgery is no longer experimental and is a therapeutic option for patients with liver cancer in critical sites. Good anesthesia support is an essential element of liver autotransplantation.

In Vitro Generation of Functional Liver Organoid-Like Structures Using Adult Human Cells

In this study we used differentiated adult human upcyte® cells for the in vitro generation of liver organoids. Upcyte® cells are genetically engineered cell strains derived from primary human cells by lenti-viral transduction of genes or gene combinations inducing transient proliferation capacity (upcyte® process). Proliferating upcyte® cells undergo a finite number of cell divisions, i.e., 20 to 40 population doublings, but upon withdrawal of proliferation stimulating factors, they regain most of the cell specific characteristics of primary cells. When a defined mixture of differentiated human upcyte® cells (hepatocytes, liver sinusoidal endothelial cells (LSECs) and mesenchymal stem cells (MSCs)) was cultured in vitro on a thick layer of Matrigel™, they self-organized to form liver organoid-like structures within 24 hours. When further cultured for 10 days in a bioreactor, these liver organoids show typical functional characteristics of liver parenchyma including activity of cytochromes P450, CYP3A4, CYP2B6 and CYP2C9 as well as mRNA expression of several marker genes and other enzymes. In summary, we hereby describe that 3D functional hepatic structures composed of primary human cell strains can be generated in vitro. They can be cultured for a prolonged period of time and are potentially useful ex vivo models to study liver functions.

Intereukin-10 and Kupffer cells protect steatotic mice livers from ischemia-reperfusion injury

Steatotic livers are more sensitive to ischemia/reperfusion (I/R) and are thus routinely rejected for transplantation because of their increased rate of primary nonfunction (PNF). Lean livers have less I/R-induced damage and inflammation due to Kupffer cells (KC), which are protective after total, warm, hepatic I/R with associated bowel congestion. This protection has been linked to KC-dependent expression of the potent anti-inflammatory cytokine interleukin-10 (IL-10). We hypothesized that pretreatment with exogenous IL-10 would protect the steatotic livers of genetically obese (ob/ob) mice from inflammation and injury induced by I/R. Lean and ob/ob mice were pretreated with either IL-10 or liposomally-encapsulated bisphosphonate clodronate (shown to deplete KC) prior to total, warm, hepatic I/R. IL-10 pretreatment increased survival of ob/ob animals at 24 hrs post-I/R from 30% to 100%, and significantly decreased serum ALT levels. At six hrs post-I/R, IL-10 pretreatment increased IL-10 mRNA expression, but suppressed up-regulation of the pro-inflammatory cytokine IL-1β mRNA. However, ALT levels were elevated at six hrs post-I/R in KC-depleted animals. These data reveal that pretreatment with IL-10 protects steatotic livers undergoing I/R, and that phagocytically active KC retain a hepatoprotective role in the steatotic environment.

Bone marrow-derived mesenchymal stem cells attenuate acute liver injury and regulate the expression of fibrinogen-like-protein 1 and signal transducer and activator of transcription 3

In recent years, bone marrow-derived mesenchymal stem cells (BMSCs) have been demonstrated to exert extensive therapeutic effects on acute liver injury; however, the underlying mechanisms of these effects have remained to be elucidated. The present study focused on the potential anti-apoptotic and pro-regenerative effects of BMSCs in D-galactosamine (D-Gal) and lipopolysaccharide (LPS)-induced acute liver injury in rats. An experimental rat acute liver injury model was established by intraperitoneal injection of D-Gal (400 mg/kg) and LPS (80 μg/kg). BMSCs and an identical volume of saline were administered via the caudal vein 2 h after the D-Gal and LPS challenge. Subsequently, the serum samples were collected to detect the levels of alanine aminotransferase and aspartate aminotransferase. Hematoxylin and eosin staining, terminal deoxynucleotidyl transferase-mediated nick-end labeling assay and immunohistochemical staining were performed to determine apoptosis, regeneration and histological changes of liver sections. Western blotting and reverse transcription-quantitative polymerase chain reaction were performed to detect the protein and mRNA expression levels of fibrinogen-like-protein 1 (FGL1), phosphorylated signal transducer and activator of transcription 3 (p-STAT3), STAT3 and B-cell lymphoma 2 (Bcl-2) and Bcl-2 associated X protein (Bax) in liver tissue samples. The results indicated that intravenous transplantation of BMSCs significantly decreased the levels of alanine aminotransferase and aspartate aminotransferase, and reduced hepatocellular necrosis and inflammatory cell infiltration. Additionally, a terminal deoxynucleotidyl transferase-mediated nick-end labeling assay and immunohistochemical staining revealed that BMSC treatment reduced hepatocyte apoptosis and enhanced liver regeneration. Furthermore, Bcl-2 expression was increased, whilst the protein expression of Bax was reduced. The expression of FGL1 and p-STAT3 were elevated concurrently with the improvement of liver function. These results demonstrated that BMSCs may provide a promising potential agent for the prevention of acute liver injury via inhibition of hepatocyte apoptosis and acceleration of liver regeneration. The mechanism may be, a least in part, a consequence of the upregulation of FGL1 expression and the induction of STAT3 phosphorylation.

Therapeutic potential of human adipose tissue-derived multi-lineage progenitor cells in liver fibrosis

INTRODUCTION

Liver fibrosis is characterized by excessive accumulation of extracellular matrix. In a mouse model of liver fibrosis, systemic injection of bone marrow mesenchymal stem cells (BM-MSCs) was considered to rescue the diseased phenotype. The aim of this study was to assess the effectiveness of human adipose tissue-derived multi-lineage progenitor cells (hADMPCs) in improving liver fibrosis.

METHODS AND RESULTS

hADMPCs were isolated from subcutaneous adipose tissues of healthy volunteers and expanded. Six week-old male nude mice were treated with carbon tetra-chloride (CCl4) by intraperitoneal injection twice a week for 6 weeks, followed by a tail vein injection of hADMPCs or placebo control. After 6 more weeks of CCl4 injection (12 weeks in all), nude mice with hADMPCs transplants exhibited a significant reduction in liver fibrosis, as evidenced by Sirius Red staining, compared with nude mice treated with CCl4 for 12 weeks without hADMPCs transplants. Moreover, serum glutamic pyruvate transaminase and total bilirubin levels in hADMPCs-treated nude mice were lower levels than those in placebo controls. Production of fibrinolytic enzyme MMPs from hADMPCs were examined by ELISA and compared to that from BM-MSCs. MMP-2 levels in the culture media were not significantly different, whereas those of MMP-3 and -9 of hADMPCs were higher than those by BM-MSCs.

CONCLUSION

These results showed the mode of action and proof of concept of systemic injection of hADMPCs, which is a promising therapeutic intervention for the treatment of patients with liver fibrosis.