Potentials of Differentiated Human Cord Blood-Derived Unrestricted Somatic Stem Cells in Treatment of Liver Cirrhosis

Liver regeneration after injury: Mechanisms, cellular interactions and therapeutic innovations

The liver possesses a distinctive capacity for regeneration within the human body. Under normal circumstances, liver cells replicate themselves to maintain liver function. Compensatory replication of healthy hepatocytes is sufficient for the regeneration after acute liver injuries. In the late stage of chronic liver damage, a large number of hepatocytes die and hepatocyte replication is blocked. Liver regeneration has more complex mechanisms, such as the transdifferentiation between cell types or hepatic progenitor cells mediated. Dysregulation of liver regeneration causes severe chronic liver disease. Gaining a more comprehensive understanding of liver regeneration mechanisms would facilitate the advancement of efficient therapeutic approaches. This review provides an overview of the signalling pathways linked to different aspects of liver regeneration in various liver diseases. Moreover, new knowledge on cellular interactions during the regenerative process is also presented. Finally, this paper explores the potential applications of new technologies, such as nanotechnology, stem cell transplantation and organoids, in liver regeneration after injury, offering fresh perspectives on treating liver disease.

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

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

Human Umbilical Cord Blood-Derived Mesenchymal Stem Cell Transplantation for Patients with Decompensated Liver Cirrhosis

BACKGROUND OR PURPOSE

Although human umbilical cord blood-derived mesenchymal stem cell transplantation (HUCB-MSCT) resulted in a good short-term therapeutic effect on patients with decompensated liver cirrhosis (DLC), the long-term survival remained unclear. This study aimed to evaluate the impact of HUCB-MSCT on long-term outcomes in patients with DLC.

METHODS

This retrospective cohort study included hospitalized patients with decompensated cirrhosis in Liuzhou Hospital of Traditional Chinese Medicine between November 2010 and February 2013. The primary outcome was overall survival (OS). The secondary outcomes were 3-year and 5-year survival rates and the occurrence rate of hepatocellular carcinoma (HCC).

RESULTS

A total of 201 subjects were enrolled, including 36 patients who underwent HUCB-MSCT (SCT group) and 165 patients who did not (non-SCT group). After PSM (1:2), there were 36 patients in the SCT group and 72 patients in non-SCT group. The 3-year and 5-year survival rates of the two groups were 83.3% vs. 61.8% and 63.9% vs. 43.6%, and median OS time was 92.50 and 50.80 months, respectively. HUCB-MSCT treatment was found to be an independent beneficial factor for patient OS (hazard ratio = 0.47; 95% CI: 0.29-0.76; P = 0.002). There was no significant difference in the occurrence rate of HCC between the two groups (P = 0.410).

DISCUSSION OR CONCLUSIONS

HUCB-MSCT may improve long-term OS without increasing the occurrence of HCC in patients with DLC.

TRIAL REGISTRATION

The Chinese Clinical Trial Registry (ChiCTR2100047550).

Activated and nonactivated MSCs increase survival in humanized mice after acute liver injury through alcohol binging

The ability of the liver to regenerate after injury makes it an ideal organ to study for potential therapeutic interventions. Mesenchymal stem cells (MSCs) possess self-renewal and differentiation properties, as well as anti-inflammatory properties that make them an ideal candidate for therapy of acute liver injury. The primary aim of this study is to evaluate the potential for reversal of hepatic injury using human umbilical cord-derived MSCs. Secondary aims include comparison of various methods of administration as well as comparison of activated versus nonactivated human umbilical cord stem cells. To induce liver injury, humanized mice were fed high-cholesterol high-fat liquid diet with alcohol binge drinking. Mice were then treated with either umbilical cord MSCs, activated umbilical cord MSCs, or a placebo and followed for survival. Blood samples were obtained at the end of the binge drinking and at the time of death to measure alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Histology of all mouse livers was reported at time of death. Activated MSCs that were injected intravenously, intraperitoneally, or both routes had superior survival compared with nonactivated MSCs and with placebo-treated mice. AST and ALT levels were elevated in all mice before treatment and improved in the mice treated with stem cells. Conclusion: Activated stem cells resulted in marked improvement in survival and in recovery of hepatic chemistries. Activated umbilical cord MSCs should be considered an important area of investigation in acute liver injury.