Highlights From the Latest in Diabetes Research

Pluripotent embryonic stem cells (ESCs) may be generated by reprogramming somatic cells through transplantation of the somatic cell nucleus into an enucleated donor oocyte, a method referred to as somatic cell nuclear transplant (SCNT). Although this method has been successful in generating nuclear transfer-ESCs (NT-ESCs) in a variety of mammalian species, early embryonic arrest (prior to formation of the blastocyst) has prevented derivation of stable human NT-ESCs. Through systematic evaluation of the SCNT protocol, Tachibana et al. identifi ed key factors limiting its success (i.e., early exit of the oocyte from meiosis and inadequate cytoplast activation posttransplant) and optimized the approach to successfully derive the fi rst human NT-ESCs. The authors tweaked the protocol to ensure transplant into meiotically active cytoplasts, used electroporation to improve cytoplast activation, and added caffeine during enucleation and fusion to facilitate blastocyst development. They also determined that using high-quality donor oocytes (as opposed to leftover oocytes from in vitro fertilization procedures) improved ESC derivation effi ciency and yield. This breakthrough in reprogramming somatic cells into pluripotent ESCs provides the opportunity to further our understanding of biological systems and disease mechanisms. Creating cells, tissues, and organs genetically identical to a patient’s somatic cells will allow researchers to dissect the effects of gene mutations and other perturbations in tissues not easily accessible for biopsy, including liver, pancreas, and heart. Ultimately, this may help develop cell/organ transplant therapies such as neuronal cells for Alzheimer and Parkinson diseases, β-cells for diabetes, and whole organs for transplant. — Coleen M. Damcott, PhD