Chinese Scientists Reveal A New Mechanism in Stem Cell Differentiation
PEI Duanqing and SHU Xiaodong from the Guangzhou Institutes of Biomedicine and Health reveal a new mechanism in stem cell differentiation, which was newly published in international academic journal Nature Communications online on May 3rd.
The human body is composed of about 200 trillion cells, mainly tissue cells and organ-specific functional cells, and they can be easily classified as epithelial and mesenchymal cells under the microscope. Epithelial cells is usually on the surface of tissues and organs as a barrier, while mesenchymal cells mainly contribute to the shape and softness of tissues and organs.
Pei inferred that since human embryonic stem cells are epithelial cells, the human body must be derived from epithelial cells, as well as mesenchymal cells. Scientists have already identified the epithial- mesenchymal transition process.
Scientists further estimated that mesenchymal cells can also be transformed to epithial ones. Pei Group revealed that a mesenchymal-to-epithelial transition initiates and is required for the nuclear reprogramming of mesenchymal fibroblasts in 2010.
Pei revealed a sequential EMT-MET mechanism is optimal for reprogramming in 2013 and observed mesenchymal intermediates in the differentiation of human embryonic stem cells towards hepatocytes.
4 years later, Pei Group reported that in vitro differentiation of hESCs to hepatic lineage undergoes a sequential EMT-MET with an obligatory intermediate mesenchymal phase. Previous studies suggested that somatic reprogramming and stem cell differentiation are largely different, but this study has made a great progress in unifying both.
Stem cell research is a hot topic in the academic field, but the application of stem cells is limited due to the lack of application research with thorough mechanism. Pei expects to establish a universal model of regulating cell fates based on "EMT-MET", and opens a window for the application of stem cells in regenerative medicine.
The process of differentiation from human stem cells towards hepatocytes (Image by GIBH)
The EMT/MET related gene expression change during the process of differentiation from human stem cells towards hepatocytes (Image by GIBH)