Changes of gene expression related to cellular senescence in human umbilical cord-derived mesenchymal stem cells

Mesenchymal stem cells (MSCs) are recognized as potential treatments for multiple degenerative and inflammatory disorders as a number of animal and human studies have indicated their therapeutic effects. There are also several approved medicinal products manufactured using these cells. For large-scale manufacturing requirements, the in vitro expansion of harvested MSCs is essential. Multiple subculturing of MSCs, however, provokes cellular senescence process which is known to deteriorate the therapeutic efficacy of the cells. Strategies to rejuvenate or selectively remove senescent MSCs are therefore highly desirable for fostering future clinical applications of these cells. In this present study, we investigated gene expression changes related to cellular senescence of MSCs derived from umbilical cord blood (hUCB-MSCs) and found that CD26, also known as DPP4, is significantly upregulated upon cellular aging. For differental gene expression analysis between pre-senescent and senescent MSCs, microarray was performed using the Affymetrix GeneChip (Human Gene 2.0 ST Array; DNA Link, Inc, Korea). Total RNA obtained form passage 4 or passage 9 MSCs was extracted and used. two biological replicates of each passage were analyzed.