New progress in the basic research of stem cells / 基础医学与临床

ABSTRACT

During the recent 5 years,an upsurge of stem cell biology research has appeared around the world with a huge number of papers published.A part of them,however,concluded with a hypothesis of so called "transdifferentiation" or "stem cell plasticity" that stem cells could transform into any other tissues such as fats becoming liver or muscle changing into nervous cells and so on,that all lacks of strong evidence.The discovery of adult stem cells(ASC) in the adult tissues was actually a great scientific epoch-making towards the end of 1999 though the authors made a wrong conclusion of transdifferentiation at that time.More and more evidences showed that the ASC in the adult tissue are the remnants of stem cells from every stage of embryonic development.The tissue specific stem cells harbored in the adult tissues can only be induced to differentiate in the progeny cells of its own committed origin.ASC includes hematopoietic and non-hematopoietic stem cells and there are lots of stem cells in the latter,like nervous stem cells and mesenchymal stem cells(MSC).The progenies of MSC are the connective tissues,such as osteoblasts,chodroblasts,myocytes,angio-endothelio cells,etc,which are most important during the recovery and reconstitution of tissue injury,ischemic necrosis and hematopoietic damage.