Induced Pluripotency With Long Telomeres

As noted at In the Pipeline, researchers have recently generated a line of induced pluripotent stem (iPS) cells with long telomeres. Though no-one yet knows the precise cause, now that these cells exist as a point of comparison determining how to do it for all iPS cells will follow in time. Unfortunately, it has been somewhat overhyped in the press: this is just a promising step forward in the search for a solid, cheap source of patient-specific stem cells for regenerative medicine, not a sign of aging-reversal. "It seems to be interesting work that's a long way from application. Briefly [what] they're looking at is telomere length in various stem cell lines. Telomere length is famously correlated with cellular aging - below a certain length, senescence sets in and the cells don't divide any more. What's become clear is that a number of 'induced pluripotent' cell lines have rather short telomeres as compared to their embryonic stem cell counterparts. You can't just wave a wand and get back the whole embryonic phenotype; their odometers still show a lot of wear. [Researchers] induced in such cells a number of genes thought to help extend and maintain telomeres, in an attempt to roll things back. And they did have some success - but only by brute force. The exact cocktail of genes you'd want to induce is still very much in doubt, for one thing. And in the cell line that they studied, five of their attempts quickly shed telomere length back to the starting levels. One of them, though, for reasons that are completely unclear, maintained a healthy telomere length over many cell divisions. So this, while a very interesting result, is still only that."

Link: http://pipeline.corante.com/archives/2010/03/17/biotimes_cellular_aging_results.php