Transition of clinical and basic studies on liver cirrhosis treatment using cells to seek the best treatment.

The liver is a highly regenerative organ; however, its regeneration potential is reduced by chronic inflammation with fibrosis accumulation, leading to cirrhosis. With an aim to tackle liver cirrhosis, a life-threatening disease, trials of autologous bone marrow cell infusion (ABMi) therapy started in 2003. Clinical studies revealed that ABMi attenuated liver fibrosis and improved liver function in some patients; however, this therapy has some limitations such as the need of general anesthesia. Following ABMi therapy, studies have focused on specific cells such as mesenchymal stromal cells (MSCs) from a variety of tissues such as bone marrow, adipose tissue, and umbilical cord tissues. Particularly, studies have focused on gaining mechanistic insights into MSC distribution and effects on immune cells, especially macrophages. Several basic studies have reported the use of MSCs for liver cirrhosis models, while a number of clinical studies have used autologous and allogeneic MSCs; however, there are only a few reports on the obvious substantial effect of MSCs in clinical studies. Since then, studies have analyzed and identified the important signals or components in MSCs that regulate immune cells, such as macrophages, under cirrhotic conditions and have revealed that MSC-derived exosomes are key regulators. Researchers are still seeking the best approach and filling the gap between basic and clinical studies to treat liver cirrhosis. This paper highlights the timeline of basic and clinical studies analyzing ABMi and MSC therapies for cirrhosis and the scope for future studies and therapy.