Human brains, frozen for 11 years, still yield pluripotent stem cells

>

If your morning cup of coffee wasn’t enough to wake you up today, researchers from the New York Stem Cell Foundation and Columbia University just reported being able to generate iPS cells from human brain tissue that’s been frozen for 11 years:

Induced pluripotent stem cells (iPSCs) derived from patients with neurodegenerative disease generally lack neuropathological confirmation, the gold standard for disease classification and grading of severity. The use of tissue with a definitive neuropathological diagnosis would be an ideal source for iPSCs. The challenge to this approach is that the majority of biobanked brain tissue was not meant for growing live cells, and thus was not frozen in the presence of cryoprotectants such as DMSO. We report the generation of iPSCs from frozen non-cryoprotected dural tissue stored at −80°C for up to 11 years. This autopsy cohort included subjects with Alzheimer’s disease and four other neurodegenerative diseases.

After showing that iPS cells could be grown from brain tissue (specifically, dura mater) frozen with cryoprotectants, the team tried their technique on nine more samples that were frozen without protection at all. Without cryoprotection, many people assume that cells are damaged and sheared by ice crystals during the freezing process, which is certainly true for most organisms that haven’t evolved to cope with freezing, like woolly bear caterpillars.

The results? Four tissue samples grew out cells (as fibroblasts), and of those, one became contaminated and another didn’t grow enough cells for reprogramming. Of the two that were actually transformed, one looked like it yielded cells that looked like iPS cells, which after some verification, the team found that indeed, they managed to produce stem cells from a 9 year old sample that originally came from a 79 year old woman with late-onset Alzheimers.

In science, one success out of nine attempts isn’t bad.

And yes, the iPS cells could differentiate into neurons.

In a subsequent attempt with 18 more samples, the team managed to get iPS cells from another three people, this time from patients with amyotrophic lateral sclerosis (ALS), Huntington’s disease, and Parkinson’s disease. This cohort included the sample that was frozen for eleven years, and what’s more amazing is that time between patient death and freezing of cell samples was up to 39 hours.

Why is all of this interesting, you ask? Reprogramming somatic cells into iPS cells isn’t a routine technique that’s practiced in every lab — and some people that can do it still may say that it’s a bit of an art. With this neat paper, these researchers show that human cells are actually much more resilient than commonly believed, and that even cells stored in samples assumed to be useless for cell studies can be brought back to life, so to speak.