Mesenchymal stem cells (MSCs) with their multilineage developmental plasticity comprise a promising tool for regenerative cell-based therapy. Despite important biological properties, which the MSCs from different sources share, the differences between them are poorly understood. Hence, it is required to assign a molecular signature to each of these MSC populations, based on stem cell related genes and early lineage or developmental markers. Understanding their propensity to differentiate to different lineages is fundamental for the development of successful cell-based therapies. Culture expansion of MSCs is a prerequisite, since high absolute numbers of stem cells are required to attain a clinical dose. Here, we compared the different culture conditions for long-term expansion of human MSCs isolated from the Wharton's jelly (WJ) of the umbilical cord while preserving their stem cell characteristics and differentiation potential. We find that DMEM-KO and DMEM-F12 are superior as compared to the other media tested in supporting the in vitro expansion of the WJ-MSCs. We studied the gene expression profile of WJ and bone marrow-derived MSCs (BM-MSCs) both at early and late passages using Human Stem Cell Pluripotency Array, and our data revealed differences at the transcriptional level between the two MSC types. Compared to BM-MSCs, WJ-MSCs had higher expression of undifferentiated human embryonic stem cell (hES) markers like NANOG, DNMT3B, and GABRB3, pluripotent/stem cell markers, as well as some early endodermal markers both at early and late passages. To conclude, WJ-MSCs possess properties of true stem cells, which they retain even after extended in vitro culturing.

AIMS AND OBJECTIVES: 1. Isolation and growth of dental pulp stem cells (DPSCs) and stem cells from exfoliated human deciduous teeth (SHED). 2. Characterization of dental pulp stem cells (DPSCs) and stem cells from exfoliated human deciduous teeth (SHED). METHODS: The pulp tissue was digested in collagenase and cultured in DMEM Dulbecco’s Modified Eagle’s Media). The stem cells were identified and isolated. Surface characterization of cells was done with the help of flow cytometer using a panel of various surface markers. An immuno cytochemistry analysis was done to see the expression of proteins in the cells. RESULTS: Identification of cells was done with the help of a phase contrast microscope. Flow cytometry analyses for various CD markers showed similar results for both DPSCs and SHED. The cells showed positive expression for pluripotent markers, ectodermal markers and mesodermal markers. CONCLUSION: The study demonstrated that stem cells existed in human deciduous and permanent pulp tissue. The stem cells present in deciduous permanent pulp tissue can be isolated, cultivated and expanded in vitro. Both DPSCs and SHED show almost a similar expression pattern profile for variety of antigens tested. Further studies should include analysis of diverse cell populations to elucidate their potential to differentiate into various cell types followed by in vivo studies in animals and humans.