Cells and Stem Cells

We are all born out of a single cell, which contains the entire genetic information that allows it to multiply and grow into an embryo, then differentiate to produce the 250 different types of specialized cells that make the various tissues, organs and body parts that make us men and women. These cells in the embryo are the 'stem' out of which the rest of specialized cells emerge. While almost our cells containing the same genetic information as the embryonic stem cells, specific genes in each one of these differentiated cells are silenced, or otherwise regulated. Can one therefore save some of these embryonic stem cells (ESCs), store them and use them for later purposes (say to grow an organ and replace a diseased or non-functioning one with the lab-grown one)? This is the promise of stem cell biology and therapy. 

We have since discovered that even some organs store stem cells (we call these 'adult stem cells', to differentiate from the all-powerful ESCs), for its own use, but can also be 'differentiated' to generate some other cell types (but not the whole individuals which ESCs can). This then obviates the use of ESCs, when possible. 
Further, it has been found that any cell in the body (say, the already differentiated skin cells) can now be induced to become a stem cell, which has the potential to generate a variety of other cell types. This is done by introducing certain genes (or proteins) into the skin cell. This generates what are called induced pluripotent stem cells (iPSCs). 
In this talk, I shall describe the abilities of ESCs, and also how adult stem cells are used in our institute to regenerate the corneal surface cells, allowing us to replace the damaged cornea by the lab-produced regenerated tissue, and restore some vision. Ours happens to be the largest successful such stem cell therapy anywhere.