Embryonic stem cells are the most powerful stem cell type having limitless ability to turn into any type of specialized cells and also replicate into more stem cells. As they form the core of human life, obtaining these embryonic stem cells will destroy the embryo and may create ethical issues, if used in research.
To overcome this shortcoming, researchers have shifted their focus to induced pluripotent stem cells (iPSCs) also known as reprogrammed stem cells. iPSCs are specialized adult body cells such as skin cells which can be coaxed to form embryonic like stem cells by adding various genes to these adult cells. As they are retrieved from the patient’s own body, they will not cause any ethical objections and are widely preferred by scientists across the world due to their potential similarity to embryonic stem cells. However, some researchers have questioned the ability of these reprogrammed stem cells and hesitant to use them. Based on some studies, the efficiency of iPSCs are not clear and there is still controversy about the functional similarities of these two stem cell types. A new research study suggests that both these cells are equivalent in terms of their functions.
According to stem cell researcher, Konrad Hochedlinger of Massachusetts General Hospital, Boston, it is important to determine whether IPSCs and embryonic stem cells (ES cells) are comparable as clinical trials of both these stem cell types are underway. Hochedlinger and his team were able to observe the following:
Gene Activity of iPSCs and ES cells
Usually, the gene activity tends to show different patterns due to several factors. The embryo used to retrieve ES cells are genetically different from the donor adult cells which are used to create iPSCs, so researchers expect some gene discrepancies based on the source of these cells. Also, the sex of the stem cells may cause difference because the gene activity varies between males and females.
To rule out the difference in gene activity, the researchers used ES cells and allowed them to mature so that they can be coaxed into iPSCs to check if they are genetically matching their ES cell parents. The researchers were able to measure the gene activity and found them to be more similar.
Functionality Of Genes
However, the activity of a set of 49 genes seems to differ in both the cell lines which raised concerns about their capabilities. The researchers used 2 genes to analyze; one can help the cells to imbibe glucose and the other can help the cells to break it (glucose) down to energy. Although the genes were less active in iPSCs, they were just as efficient as embryonic stem cells when it comes to absorbing and digesting glucose. This can prove that both the cells are functionally equivalent.
Pluripotency Of Stem Cells
The most important factor in stem cell comparison is their ability to produce different cell types. Both the cell types were able to produce equally good nervous system cells and three other major cell lineages in the body. No difference was observed between the specialized cells produced by iPS cells and ES cells.
All these factors confirmed that the two cell types are functionally indistinguishable. “It is a well done study and it’ll ease some of the concerns about embryonic stem cells Vs induced pluripotent stem cells,” says stem cell biologist Joseph Wu of Stanford University School of Medicine, California. William lorry, stem cell biologist of University of California, LA believes that studies like this can make it a lot easier to go forward with iPSCs.