Discovered in the early 1960s by Toronto scientists Dr. James Till, a biophysicist, and Ernest McCulloch, a hematologist, a stem cell is an undifferentiated cell that has the ability to develop into various types of specialized cells within the body. Stem cells have the capacity for self-renewal, meaning they can divide and create more stem cells. They can also differentiate into different cell types with specific functions. This unique property makes stem cells crucial for the growth, repair, and maintenance of tissues and organs in the body.
There are several types of stem cells, including:
Embryonic stem cells (ESCs): These are derived from embryos at the blastocyst stage (usually within the first week of development). Embryonic stem cells have the highest developmental potential and can give rise to virtually any cell type in the body.
Adult stem cells (also known as somatic or tissue-specific stem cells): These are found in various tissues and organs throughout the body, such as the bone marrow, brain, skin, and liver. Adult stem cells are responsible for tissue repair and regeneration in their respective locations and have a more limited range of differentiation compared to embryonic stem cells.
Induced pluripotent stem cells (iPSCs): These are adult cells that have been reprogrammed to behave like embryonic stem cells. Scientists can manipulate certain genes in adult cells to induce pluripotency, allowing them to differentiate into various cell types. For this reason, iPSCs hold great promise for regenerative medicine and disease modeling.
Stem cells play a crucial role in both embryonic development and tissue repair throughout a one's life. They have tremendous potential in medical research and therapeutic applications, including regenerative medicine, the study of developmental processes, and the treatment of various diseases and conditions. Check out the Stem Cell History Timeline to see how stem cell research has progressed over the decades.