Isolation, characterization and multilineage differentiation potential of Wharton s jelly mesenchymal stem cells

Background: Wharton s jelly, as the matrix of umbilical cord, contains two major populations of cells including fibroblast like cells and primitive stromal cells. The majority of these primitive stromal cells are fibroblast like while the others demonstrate round shape. They express F-actin protein and can be aggregated as the colony like structures which express alkaline phosphatase. These primitive stromal cells display the characteristics of mesenchymal stem cells, as they have great expansion capacity and express mesenchymal markers like CD44, CD73, CD90 and CD105. But, the expression of CD34 and CD45 is negative in these cells. In addition, osteogenic and adipogenic induction of these cells results in differentiation into osteoblast and adipocyte cells.Objective: In our experiments we analyzed the multi lineage differentiation of these cells.Materials and Methods: Parallel to other researches, in our studies we have observed that under the induction media they can differentiate toward special cell lineage. For example, in our studies we observed that under the induction of retinoic acid, dimethyl sulfoxide, fibroblast growth factor and epidermal growth factor, these cells can differentiate to the cells of neural system and the differentiated cells express the neural stem/progenitor cell marker nestin. Also, we concluded that retinoic acid was the main inducer for neuron and oligodendrocyte formation while for astrocyte differentiation, DMSO was crucial. Beside the several previous studies for pancreatic islet like differentiation, in our trial we proposed a new modified induction protocol together with hanging drop culture system which led to the formation of pancreatic islet like cells and production of significantly higher amounts of insulin and proinsulin than the other most common protocols. Another organized study was on Wharton s jelly mesenchymal stem cells differentiation into cardiomyocytes like cells. In this study, under the induction of different cocktails including 5-azacytidine, ascorbic acid, hypoxia and conditioned medium, derived from neonatal heart cell culture, we observed that the umbilical cord mesenchymal stem cells exhibited cardiac cell morphology and expressed GATA, conexin43, alpha actin and cardiac troponin.Results: Differentiation of these cells to other kinds of cells including hepatocyte like cells, bone, fat and muscle has been reported, repeatedly. Altogether, on the bases of our results we affirm the mesenchymal nature and in vitro multilineage differentiation capacity of Wharton s jelly mesenchymal stem cells.Conclusion: Previously, the idea was that, Wharton s jelly mesenchymal stem cells exhibit multipotent differentiation capacity and can differentiate into several cellular lineages. But since there are several reports regarding their differentiation to germ like cells as well, we can propose these cells as pluripotent stem cells. Therefore, differentiation capacity into multiple tissue cells makes them a good candidate with various abilities for cell therapy procedures.

Keywords:

Wharton s Jelly , Mesenchymal Stem , Multilineage Differentiation