Week 2: Stem Cells

Stem cells are body cells that have been made to revert to an embryo-like state without eggs or embryos. This reversal can rejuvenate cells so therefore they can be very productive in curing diseases. There are fluorescent markers on the cells which indicates pluripotency. Pluripotency is the cell's ability to develop any type of tissues. In 2006 the formula that creates induced pluripotent stem cells (iPSCs) was released. These can come from skin cells. Typically cells in the body become more specialized as they age in differentiation. They are only un-specialized for a short amount of time in the early stages in the embryo this is (pluropotent). In late embryo stage cells can already reach specialization for a specific tissue area such as in muscles which is called multipotent. Mature cells can be reprogrammed to be more "immortal". The older approach to this was to use manipulations in adult cells to trick it to behave like an embryonic cell. This older approach is "cloning" which means to insert genetic material from an adult cell into an egg cell, that has removed DNA. This has been successful with a case of a sheep (Dolly )but hasn't been successful for humans yet. You can produce iSPCs with four genes and this can reprogram using retroviruses as "vessels".  Some cells can not become iSPCs though because important genes can not always be turned on. Retroviruses are sometimes a problem because it can damage DNA when it is trying to reprogram. Adneoviruses could be used as a vessel because they remain for a short amount of time and only the amount of time that is really needed for the converting. These iSPCs can cure sickle cell anemia in mice now. However it has not been successful to use them to replace an organ yet.