The two commonly studied types of pluripotent stem cells (PSCs) are embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs).
Embryonic Stem Cells (ESCs)
- Source: ESCs are derived from the inner cell mass of a blastocyst, which is an early-stage embryo.
- Derivation Process: The inner cell mass is isolated and cultured in vitro, allowing the ESCs to proliferate and maintain their pluripotency.
- Characteristics: ESCs are characterized by their ability to differentiate into any cell type in the body (pluripotency) and their capacity for self-renewal (ability to replicate indefinitely).
- Ethical Considerations: The derivation of ESCs involves the destruction of embryos, raising ethical concerns for some.
Induced Pluripotent Stem Cells (iPSCs)
- Source: iPSCs are generated from adult somatic cells (e.g., skin cells, blood cells) that have been reprogrammed to regain pluripotency.
- Reprogramming Process: The reprogramming is typically achieved by introducing specific genes or factors (often called Yamanaka factors: Oct4, Sox2, Klf4, and c-Myc) into the somatic cells.
- Characteristics: iPSCs share similar characteristics to ESCs, including pluripotency and self-renewal. They can differentiate into any cell type in the body.
- Advantages: iPSCs offer a significant advantage over ESCs because they bypass the ethical concerns associated with embryo destruction. They also allow for the creation of patient-specific stem cells, which can be used for personalized medicine and disease modeling.
| Feature | Embryonic Stem Cells (ESCs) | Induced Pluripotent Stem Cells (iPSCs) |
|---|---|---|
| Source | Blastocyst (embryo) | Adult somatic cells |
| Derivation Method | Isolation of inner cell mass | Reprogramming with specific factors |
| Ethical Concerns | Yes (embryo destruction) | Generally fewer, if any. |
| Patient-Specificity | No | Yes (can be patient-specific) |
