WIP 151 - Maintenance of Stemness in Placenta Mesenchymal Stem Cells Through Multiple Passages

Poster Number: WIP 151
Publication Number: WIP 151.978

Background: Aging is a biological process defined as a progressive decline of function that eventually results in cell death with failure to replace cells due to a decline in stem cells ability to sustain replication and cell divisions. MSCs play an important role in immune modulation and tissue regeneration. Previous studies have shown that a large number of MSCs are required for regenerative therapy. Human placental is a feasible source for MSCs. It is important that during expansion of MSCs to remain without advance of their biological age as measured by telomere length (TL), and maintenance of stem cell factors. Cellular senescence can occur with multiple passages. β-galactosidase activity has been used as a marker of cellular senescence. Such senescence-associated β-galactosidase (SA-β-GAL) labeling appears enhanced in degenerating cells that are affected by programmed cell death. Cells with strong SA-β-GAL signals undergo apoptosis. Previously, we have shown that there is no statistically significant change in TL in the first 5 passages of placental MSCs expansion.

Objective: To determine if stemness is maintained through multiple replicative cycles up to passage 10 of placental (Pl) and Warton Jelly (WJ) derived MSCs and to examine any change in TL and the factors that contribute to stemness such cell morphology, doubling time and MSCs surface markers. Using SA-β-GAL can increase the specificity and efficiency of detecting MSCs cellular senescence after multiple passages.

Design/Methods: Michigan State University and Sparrow Hospital, Lansing, Michigan approved the study. Maternal informed consents are obtained from healthy term pregnancies. Pl and WJ are used to isolate, culture and expanded MSCs through passage 10. DNA from MSCs is extracted and TL is measured using qPCR Assay Kit. Stemness is analyzed through cell morphology, calculating doubling time, and characterizing MSCs surface markers and stemness markers. SA-β-GAL will be used to detect if there is any cellular senescence in MSCs after multiple passages.