Posts Tagged ‘Protein transduction’
Human ES Cell Differentiation
Posted by admin in stem cells on June 21st, 2009
The widespread availability of huES cells to most laboratories shortly after their isolation – together with the progressive realization that progress with mouse ES cells might not be immediately translatable to their human counterparts – led to a sudden shift of starting material for pancreatic differentiation experiments. The report that arguably initiated this general move toward huES cells was conducted by Assady and collaborators in 2001. Both in adherent and suspension conditions, spontaneous huES cell differentiation resulted in the generation of insulin-producing cells as early as 2 weeks after the initiation of the protocol (peaking at day 19). Their number was relatively small, as only 60% of the EBs had positive staining and only 1–3% of the cells within these showed cytoplasmic insulin signal. In addition, glucose responsiveness was absent, probably due to the difficulty of detection in such a small representation of cells. Read the rest of this entry »
Stem Cell Differentiation: General Approaches
Posted by admin in stem cells on June 21st, 2009
Regardless of the cell type used as a building block for differentiation/ transdifferentiation into pancreatic cells, there are only a few strategies that can be used to modify, both in vitro and in vivo, their fate and behavior. Conventional approaches are based on the addition of chemical soluble agents to the culture medium (signal-driven strategies), in an attempt to mimic the complex symphony of differentiation/specification factors that drive the process in vivo. Extracellular matrices and cell growth substrates may help increase the overall efficiency of these methods. Alternatively, external signaling can be bypassed by means of adding constitutively activated copies of key transcription factors or – more recently – cell-permeable proteins. The rationale of in vivo differentiation is that only the recipient’s body can provide developing cells with the adequate microenvironment to support terminal maturation. Read the rest of this entry »