Stem cells are a unique type of cell in the human body that have the ability to develop into any other type of cell. They hold great potential for medical applications, and researchers are currently conducting trials to use stem cells to replace damaged cells in diseases such as Parkinson’s.
There are two main ways to obtain stem cells. One method involves using human embryos, but this raises ethical concerns and has practical limitations. The other method involves reprogramming adult cells from the skin or other tissues into induced pluripotent stem cells (iPS cells).
However, iPS cells sometimes retain a “memory” of their previous cell type, which can make them less predictable and efficient when attempting to transform them into other cell types.
In a recent study published in Nature, researchers have discovered a way to erase this memory and make iPS cells function more similarly to embryonic stem cells. This finding holds great promise for regenerative medicine, which focuses on regrowing, repairing, or replacing damaged or diseased cells, organs, or tissues.
One advantage of iPS cells is that they can be made from a patient’s own tissue, reducing the risk of rejection by the immune system.
While research using iPS cells is advancing rapidly, there are still technical challenges to overcome. Scientists are working on better controlling the differentiation of iPS cells into specific cell types and ensuring the safety of the process.
One particular challenge is “epigenetic memory,” where iPS cells retain traces of their previous cell type. The epigenome, which controls gene activity without altering the DNA sequence, plays a role in determining cell type.
When reprogramming a mature cell into an iPS cell, the goal is to erase all the epigenetic marks. However, this is not always successful, and some marks may remain, influencing the behavior of the iPS cells.
This can hinder the use of iPS cells in regenerative medicine because it affects the process of transforming them into desired cell types and may impact their function once created. For example, if iPS cells have a “memory” of being skin cells, they may not function effectively as pancreatic cells if used for repairing a pancreas.
The researchers in the study found a way to more completely erase epigenetic memory in iPS cells. By mimicking the natural reset of the epigenome that occurs during early embryo development, they were able to create iPS cells that closely resemble embryonic stem cells.
Clearing epigenetic memory in iPS cells enhances their medical potential by allowing them to behave like “blank slates” similar to embryonic stem cells. This increases the likelihood of transforming them into any desired cell type.
If iPS cells can forget their previous identities, they can be more reliable in becoming any type of cell and help generate specific cells needed for therapies, such as insulin-producing cells for diabetes or neuronal cells for Parkinson’s. Additionally, reducing epigenetic memory could minimize unexpected behaviors or complications when using iPS cells in medical treatments.
