This study investigates the difference between embryonic stem cells ES cell and Induced pluripotent stem cell iPS cell and which is better in regenerative medicine use through an analysis of available documents and reports. Both of these stem cells can differentiate into almost any type of cell and can replicate indefinitely, however there are two main differences between these two stem cells. The differences are that (1) a cell has the exact same DNA as someone cannot be created from ES cells while this is possible using Induced pluripotent stem cell and (2) embryonic stem cell needs to use a fertilized egg or an early-stage embryo to make, however Induced pluripotent stem cell can be made without destructing these. Because of these advantages, Induced pluripotent stem cell might be more useful in use of regenerative field. However, there are some problems of Induced pluripotent stem cell.
INTRODUCTION
Stem cells are cells that are in all multicellular organisms including human. Stem cell have two significant features. The first feature is the potency that means the cell can divide and differentiate into diverse specialized cell types [1]. The second feature is the self-renewal that means the cell can go through many cycles of cell division while maintaining the potency. There are five types of stem cells by the difference of their potency. First is the Unipotency stem cell. This type can differentiate into only one kind of cell type, their own, however have the ability of self-renewal, which differ them from non-stem cells. The second type is Oligopotent stem cell which can differentiate into few cell types, such as myeloid or lymphoid stem cells. The third type is Multipotent stem cell which can differentiate into many kinds of cell types, however only those of a close relationship. The fourth type is Pluripotent stem cells which can differentiate into all cell types except Embryos organizations like placenta. The fifth type is Totipotency stem cell which can differentiate into all cell types like Multipotency stem cell and can also produce Embryos organizations. Fertilized egg is the only Topptency stem cell.
Pluripotency stem cell has lately attracted considerable attention in regenerative medicine field. The reason is that, they can divide and change into almost all tissues remaining the self-renewal. Pluripoteny stem cells have two typical type, they are embryonic stem cells (ES cell) and Induced pluripotent stem cell (iPS cell).
In this paper, I will investigate the difference between embryonic stem cells (ES cell) and Induced pluripotent stem cell (iPS cell). Induced pluripotent stem cell (iPS cell) is a very hot topic because Dr. Yamanaka won a Nobel Prize in 2012 in this field. In addition, I will discuss which is better in regenerative medicine use and problems.
METHOD
This study has been based on analysis documents and reports found using Internet resources. Using keyword "stem cell," the information of stem cell was located from online encyclopedia, Wikipedia [1] using Google. Using keyword "Embryonic stem cell", the information of embryonic stem cell was located from Wikipedia [2] using Google. Using keyword "iPS cell," the information of iPS cell was located from Wikipedia [3] using Google. Using keyword "ES iPS difference," the information of the difference between ES cell and iPS cell came from online articles [4], [5], [6] using Google.
RESULT & DISCUSSOIN
Embryonic stem cells (ES cell) are isolated from the inner cell mass of blastocyst which is an early-stage of an embryo that has the ability of totipotency [2]. As written in the instruction, human embryonic stem cells can differentiate into all cell types and also can replicate indefinitely [2]. Therefore they took attention as a source of cells for transplantation or tissue engineering [2]. However, there are ethical problems in embryonic stem cells. The ethical problem is that making embryonic stem cells results in distraction of fertilized egg or an early-stage embryo [2]. This means that incase of human, making human embryonic stem cells needs to destroy a sprout of life. This issue includes whether or not the moral status of a human being should be applied to a potential human life at the early-stage of embryo.
Induced pluripotent stem cells (iPS cell) are derived from adult tissues that do not have the ability of pluripotency [3]. However, these can differentiate into all cell types and can self-renew like embryonic stem cells. Induced pluripotent stem cells are reprogrammed by modifying four key genes using retroviruses, and turn them into embryo-like state [3].
There are two main differences between embryonic stem cell and Induced pluripotent stem cell. The first main difference is that a cell that has the exact same DNA as someone cannot be created from ES cells while this is possible using Induced pluripotent stem cell. The reason why embryonic stem cell cannot be used is that it is impossible to make a fertilized egg or an early-stage embryo that has the exact same DNA as someone who exists right now. In the use of tissue engineering and transplantation, it is recommended that the new tissue that is made by stem cell has the exact same DNA as someone who needs the tissue. Therefore, embryonic stem cell is difficult to use in transplantation or tissue engineering. The second main difference is that embryonic stem cell needs to use a fertilized egg or an early-stage embryo to make, however Induced pluripotent stem cell can be made without destructing these. Therefore it can be a fundamental solution for the ethical problem that embryonic stem cell has. This is the reason why Induced pluripotent stem cell is attracting worldwide attention in the regenerative medicine field.
However, there are some problems of using Induced pluripotent stem cell in regenerative medicine field. Induced pluripotent stem cell is more fragile, slower to divide and less efficient in generating specific cells than embryonic stem cell [6]. In addition, there are genetic differences between embryonic stem cell and Induced pluripotent stem cell [6]. Because their origins are different, it is difficult to determine whether these different parts are from the source, or from the intrinsic differences between the cell types [6].
CONCLUSION
Induced pluripotent stem cell can perhaps make a tissue that has the exact same DNA with the patient that needs the tissue for transplantation. In addition it does not need to destruct a fertilized egg or an early-stage embryo to make it, thus it can be a fundamental solution for the ethical problem that embryonic stem cell has. Because of these advantages, Induced pluripotent stem cell might be more useful in use of regenerative field. However, there are some problems that have to be solved of Induced pluripotent stem cell. Future research will try to find the way to make Induced pluripotent stem cells and increase them steady and the way to make the Induced pluripotent stem cell divide into the objective tissue.
