02 Cells cure diseases

Our “body” is a “cell mass”. It consists of about 220 types of cells and a total of about 60 trillion cells. Our body is derived from a fertilized egg (one cell in which the egg and sperm are fused), then the fertilized egg proliferates by cell divisions and changes into about 220 types of cell (cell differentiation). In the end, human beings are formed as about 60 trillion “cell clusters”.
The “body” formed in the way above is changing continuously throughout life. For example, skin cells are replaced with new cells every day, and old cells are peeled off as “smudge”. Gastrointestinal cells are also replaced every day, and blood cells as well. Cells also make new bones when a fracture occurs. Like these, replacement and/or reconstitution of cells is ordinarily occurred in our body.
“Regenerative medicine” is a new medicine to utilize the characteristics of cells above so as to cure diseases or external injuries. In this field induced pluripotent stem cells (iPS cells) are payed attention so much, since iPS technology is an innovative technology developed in Japan. iPS cells can be made easily from skin cells or blood cells, and can change to all types of cell in our body.