Various stem cells gradually turned to be critical players in tissue engineering and regenerative medicine therapies. Current evidence has demonstrated that in addition to growth factors and the extracellular matrix, multiple metabolic pathways definitively provide important signals for stem cell self-renewal and differentiation. In this review, we mainly focus on a detailed overview of stem cell metabolism in vitro. In stem cell metabolic biology, the dynamic balance of each type of stem cell can vary according to the properties of each cell type, and they share some common points. Clearly defining the metabolic flux alterations in stem cells may help to shed light on stemness features and differentiation pathways that control the fate of stem cells.

Mesenchymal stem cells (MSCs) are multipotent; non-hematopoietic stem cells. Because of their immunoregulatory abilities; MSCs are widely used for different clinical applications. Compared with that of other immune cells; the investigation of how MSCs specifically regulate B-cells has been superficial and insufficient. In addition; the few experimental studies on this regulation are often contradictory. In this review; we summarize the various interactions between different types or states of MSCs and B-cells; address how different types of MSCs and B-cells affect this interaction and examine how other immune cells influence the regulation of B-cells by MSCs. Finally; we hypothesize why there are conflicting results on the interaction between MSCs and B-cells in the literature.

Liver failure is a severe clinical syndrome with a poor prognosis. Mesenchymal stem cell (MSC) transplantation has emerged as a new intervention in treating liver failure. It is conventionally recognized that MSCs exert their therapeutic effect mainly through transdifferentiation. Recently, published articles have shown that MSCs work in liver failure by secreting trophic and immunomodulatory factors as well as extracellular vesicles (EVs) before transdifferentiation. In particular,MSC-derived EVs have shown similar curative effects as MSCs. Here we review the role of MSCs as well as their derived factors and EVs in liver failure and discuss the use of MSC-derived EVs instead of intact MSCs in treating liver failure.Electronic supplementary materialThe online version of this article (doi:10.1186/s13287-017-0576-4) contains supplementary material, which is available to authorized users.