Published online Jan 26, 2019. doi: 10.4252/wjsc.v11.i1.1
Peer-review started: October 15, 2018
First decision: November 1, 2018
Revised: November 6, 2018
Accepted: January 10, 2019
Article in press: January 10, 2019
Published online: January 26, 2019
Cellular reprogramming and induced pluripotent stem cell (IPSC) technology demonstrated the plasticity of adult cell fate, opening a new era of cellular modelling and introducing a versatile therapeutic tool for regenerative medicine. While IPSCs are already involved in clinical trials for various regenerative purposes, critical questions concerning their medium- and long-term genetic and epigenetic stability still need to be answered. Pluripotent stem cells have been described in the last decades in various mammalian and human tissues (such as bone marrow, blood and adipose tissue). We briefly describe the characteristics of human-derived adult stem cells displaying in vitro and/or in vivo pluripotency while highlighting that the common denominators of their isolation or occurrence within tissue are represented by extreme cellular stress. Spontaneous cellular reprogramming as a survival mechanism favoured by senescence and cellular scarcity could represent an adaptative mechanism. Reprogrammed cells could initiate tissue regeneration or tumour formation dependent on the microenvironment characteristics. Systems biology approaches and lineage tracing within living tissues can be used to clarify the origin of adult pluripotent stem cells and their significance for regeneration and disease.
Core tip: Several types of human adult pluripotent stem cells have been described. Their origin and role remain largely unknown. The elucidation of possible stress-induced pluripotency phenomena could enable regenerative as well as tumour-suppressive therapies.