Chapter 21: Pluripotent Stem Cell Applications

Pluripotent Stem Cell Applications distinguishes between embryonic stem cells (ES cells), which originate from the inner cell mass of preimplantation blastocysts, and induced pluripotent stem cells (iPS cells), created by reprogramming adult somatic cells using specific transcription factors known as Yamanaka factors. A significant portion of the text discusses the foundational success of hematopoietic stem cell transplantation while highlighting the critical challenges of immunological rejection, the necessity of human leucocyte antigen (HLA) matching, and the risks of graft-versus-host disease. The exploration extends to historical breakthroughs in somatic cell nuclear transfer (SCNT) and the innovative methods used to enable the creation of patient-specific iPS lines, which may bypass the ethical concerns associated with embryo use and the clinical hurdle of immune rejection. Furthermore, the chapter details the methodology for directed differentiation, where stem cells are guided through developmental hierarchies to become specialized cell types. These include insulin-producing beta cells for treating type 1 diabetes, dopaminergic neurons for Parkinson’s disease, cardiomyocytes for repairing heart tissue after a myocardial infarction, and retinal pigment epithelium for combating macular degeneration. Clinical progress is also noted in the use of oligodendrocytes for spinal cord repair. Despite these breakthroughs, the text emphasizes the rigorous safety standards required to prevent teratoma formation, the complexities of direct reprogramming, and the necessity of adhering to Good Manufacturing Practice (GMP) to ensure that future therapies are both effective and safe for human patients.