Evaluation of a new standardized enzymatic isolation protocol for human umbilical cord-derived stem cells

The umbilical cord (UC) represents an important source of mesenchymal stem cells (MSC). These human UC-derived MSC (UC-MSC) have already been isolated using a protocol based on the migratory and plastic adhesive properties of MSC (UC-MSC-Mig). The UC-MSC-Mig isolation method, however, is difficult to standardize. Therefore, we developed an enzymatic isolation protocol (UC-MSC-Enz) to overcome the above mentioned disadvantages. First, we investigated the UC-MSC-Enz for their MSC properties. We found that UC-MSC-Enz express the MSC markers CD73, CD90 and CD105 and are able to differentiate into osteoblasts, adipocytes and chondroblasts fulfilling the MSC criteria of the International Society for Cellular Therapy. Previously we found that UC-MSC-Mig are unique among MSCs due to their significant expression of several hepatic (progenitor) markers. Therefore, we also investigated the expression of hepatic transcription factors and other hepatic markers in UC-MSC-Enz at both the mRNA and protein level. We found that the expression of hepatic transcription factors (GATA4, GATA6, SOX9 and SOX17) and hepatic markers (AFP, DPP4, CX43, DKK1, DSG2, KRT18 and KRT19) in UC-MSC-Enz was not significantly different from those of UC-MSC-Mig. Consequently, this optimized enzyme-based method represents a fast, robust and standardized way to isolate UC-MSC for a broad range of applications.