Young Investigator 2020 awarded to extracellular vesicle researcher

Senquan Liu, Ph.D., is STEM CELLS‘s Young Investigator of 2020 for his work on human stem-cell derived extracellular vesicles (EVs). This award fosters advancements in the field of stem cell research by honoring a young researcher who is the principal author of an article published in STEM CELLS that is deemed to have the most impact and to push the boundaries of novel and insightful research.

Dr. Liu and his team at Johns Hopkins University focused on optimizing an approach to produce and purify human induced pluripotent stem cells (iPSCs) and mesenchymal stem cell (MSC) EVs, then they investigated the properties and therapeutic potential of stem cell derived EVs.

They demonstrated for the first time that human iPSCs produce great numbers of EVs under a defined culture condition, and the concentration is 16-fold higher than by MSCs. Highly purified EVs secreted from both iPSCs and young MSCs alleviated senescence associated cellular phenotypes of aged MSCs through reducing intracellular reactive oxygen species (ROS) level via exosomal transfer of PRDXs.

Production and purification of extracellular vesicles (EVs) secreted by human induced pluripotent stem cells (iPSCs) and mesenchymal stem cells (MSCs) cultured with a chemically defined medium. 


(A): Nanoparticle tracking analysis measurements of sizes and concentrations of EVs produced by human iPSCs and MSCs after an optimal dilution of 1:200 and 1:20 in volume, respectively. (B): Sizes of iPSC‐EVs and MSC‐EVs of multiple cultures (n = 16). (C): Concentrations of undiluted iPSC‐EVs and MSC‐EVs of multiple cell lines or cultures (n = 16). (D): Purification of concentrated iPSC‐EVs by qEV size exclusion chromatography. (E): Representative images of iPSC‐EVs and MSC‐EVs by transmission electron microscopy. Scale bar: 100 nm. (F): Western blots to examine the presence or absence of indicated proteins in lysates of EVs or their producing cells. All data reflect mean ± SD from ≥3 independent experiments. 

“The discovery that EVs from human stem cells can be used to alleviate cellular aging in culture by the delivery of intracellular peroxiredoxin antioxidant enzymes and other factors is an important step forward,” said Dr. Jan Nolta, Editor-in-Chief of STEM CELLS. “This knowledge could be useful for improving culture conditions and expansion without a loss in cell potency. The studies also help define shared mechanisms of aging and aging-associated diseases.”

Dr. Liu is currently an associate investigator in the Division of Life Sciences and Medicine at the University of Science and Technology of China, one of the top research universities in China.

Source – Alphamed Press

Liu S, Mahairaki V, Bai H, Ding Z, Li J, Witwer KW, Cheng L. (2019) Highly Purified Human Extracellular Vesicles Produced by Stem Cells Alleviate Aging Cellular Phenotypes of Senescent Human Cells. Stem Cells 37(6):779-790. [article]

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