Published online Oct 26, 2021. doi: 10.4252/wjsc.v13.i10.1580
Peer-review started: April 13, 2021
First decision: May 12, 2021
Revised: May 25, 2021
Accepted: September 19, 2021
Article in press: September 19, 2021
Published online: October 26, 2021
Processing time: 195 Days and 17.4 Hours
End-stage liver disease is a global health complication with high prevalence and limited treatment options. Cell-based therapies using mesenchymal stem cells (MSCs) emerged as an alternative approach to support hepatic regeneration. In vitro preconditioning strategies have been employed to strengthen the regenerative and differentiation potential of MSCs towards hepatic lineage. Chemical compounds of the triterpene class; glycyrrhizic acid (GA) and 18β-glycyrrhetinic acid (GT) possess diverse therapeutic properties including hepato-protection and anti-fibrosis characteristics. They are capable of modulating several signaling pathways that are crucial in hepatic regeneration. Preconditioning with hepato-protective triterpenes may stimulate MSC fate transition towards hepatocytes.
To explore the effect of GA and GT on hepatic differentiation of human umbilical cord-MSCs (hUC-MSCs).
hUC-MSCs were isolated and characterized phenotypically by flow cytometry and immunocytochemistry for the expression of MSC-associated surface molecules. Isolated cells were treated with GA, GT, and their combination for 24 h and then analyzed at three time points; day 7, 14, and 21. qRT-PCR was performed for the expression of hepatic genes. Expression of hepatic proteins was analyzed by immunocytochemistry at day 21. Periodic acid Schiff staining was performed to determine the functional ability of treated cells.
The fusiform-shaped morphology of MSCs in the treatment groups in comparison with the untreated control, eventually progressed towards the polygonal morphology of hepatocytes with the passage of time. The temporal transcriptional profile of preconditioned MSCs displayed significant expression of hepatic genes with increasing time of differentiation. Preconditioned cells showed positive expression of hepatocyte-specific proteins. The results were further corroborated by positive periodic acid Schiff staining, indicating the presence of glycogen in their cytoplasm. Moreover, bi-nucleated cells, which is the typical feature of hepatocytes, were also seen in the preconditioned cells.
Preconditioning with glycyrrhizic acid, 18β-glycyrrhetinic acid and their combination, successfully differentiates hUC-MSCs into hepatic-like cells. These MSCs may serve as a better therapeutic option for degenerative liver diseases in future.
Core Tip: This study focuses on exploring the effect of two triterpenes, glycyrrhizic acid and 18β-glycyrrhetinic acid to enhance the differentiation potential of mesenchymal stem cells (MSCs) into hepatocytes to ensure a potent and valuable cell source for cellular therapy for end-stage liver disease. Preconditioning of human umbilical cord-MSCs with these compounds enhances expression of both early and late hepatic markers, regulated with time of differentiation. The significant expression of hepatocyte markers, the ability to store glycogen, and presence of bi-nucleated cells, suggest successful hepatic differentiation. Preconditioned MSCs may help in the replacement of damaged hepatocytes, and improve liver function post-transplantation in impaired hepatic tissues.