Yitian Dai, Avital Mendelson
Mesenchymal stem cells (MSCs) were first described over 30 years ago as multipotent stromal cells that can self-renew and differentiate into bone, cartilage, and fat tissues. MSCs have numerous functions, such as modulating the immune system, regulating inflammation, promoting wound healing, improving engraftment following hematopoietic transplant, and providing a supportive microenvironment for hematopoietic stem cells. Human umbilical cord tissue, which is more easily obtained than bone marrow aspirates, contains a population of MSCs. These cells can enhance thrombopoiesis in umbilical cord blood-derived megakaryocytes, leading to the production of platelets with low baseline activation levels. Scaled-up methods to enhance platelet production in vitro while maintaining a low activation state would benefit transfusion medicine and circumvent frequent platelet donor shortages. Here, we outline a protocol to isolate and expand MSCs from human umbilical cord tissue and characterize their cell surface protein expression by flow cytometry, self-renewal potential by colony-forming assay, and tri-lineage differentiation capacity.