I’m overwhelmed with notes that I feel like I need to fact-check, but I’d like to get something up sooner rather than later. So here’s a speed-writing experiment. I’ve set the timer for twenty minutes, and I’ll tap out my impresssions. All of you who read this blog and have something to say (that’s not a press release), send me your links!

Here’s the first, a short write-up from someone who went to the ISSCR conference here.

The big buzz was on Doug Melton’s talk. He showed that reprogramming need not take cells all the way back to the embryonic ground state. After all, cells take weeks and weeks to differentiate out of pluripotency and into something useful. Why not avoid the backtracking and go straight to the cell state you want? He introduced a set of islet genes into non-islet pancreatic cells in mice and found that non-islet cells changed shape, started secreting insulin and responding to glucose. They helped out a diabetic mouse model. One question in my mind: when is it gene therapy, and when is it reprogramming? Is that a distinction that matters?

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But this kind of “teleport” reprogramming where you go direct from one differentiated cell type to another is clearly just budding. It’s the iPS cells that are in full fragrant bloom. People are characterizing them, making new sorts. Geroge Daley has made a whole bouquet of disease-specific sorts from patients with particular diseases, two kinds of muscular dystrophy, Gaucher’s disease, Huntington’s disease, Down’s syndrome. Dong-Wok from Korea has made some from Parkinson’s. Remember the monkey from whom cloned embryonic stem cells were made last year? He’s got (or is getting) an iPS cell line too.

9 minutes left: reprogramming needs a sense of histony

And that leads to the next thing. Really, really sophisticated characterization of epigenetic machinery in iPS cells. I think it takes a sense of histone-y. John Gurdon (so famous they named his institute after him) showed us how histones can preserve epignetic memory in reprogramming frog nuclei even after a couple dozen cell division and two exposures to the magic reprogramming mix in oocytes. He had a movie of a great histone swap-out that occurs in oocytes, and even had a model how one sort of histone could attract another, allowing their gene activation or supporession effects to be preserved. Alex Meissner at the Broad Institute analyzed how histone-based epigenetics could control extent of reprogramming and even found a way to use regulatory RNAs to kick partially reprogrammed cells into a fully reprogrammed state. And finally, Janet Rossant at the University of Toronto compared mouse iPS cells with mouse ES cells derived from the inner cell mass and the epiblast. iPS cells seem more like epiblast. There are many sorts of pluripotent cells, but they seem to have different tendencies in terms of what cells they like to become. And genetic engineering can shift them from one to another. What do we do with that information? iPS cells can even display different extents of reprogramming, perhaps making it necessary to set up a grading system for iPS. That’s something I already blogged about.

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There are also emerging tehcniques to watch stem cells both in vivo and in vitro and figure out what they are doing functionally. Kateri Moore at Mt Sinai has a cool system using inducible promoers and green fluroescent proteins to track divisions in the bone marrow niche and identified different pools of stem and progenitor cells;Jianhong Zhu at Fudan University Huashan Hospital has acutally used superparamagnetic iron oxide nanoparticles to label neural stem cells and watched them go to sites of injury in patients with head trauma (no patients have did yet in the three years of the study, so no autopsies). In vitro, the NIH’s Dan Hoeppner is using a ranibow of fluroescently tagged proteins to track how nerual cells shift into differentiation and lesser form of multipotency.

TIME.

(Checking spelling of proper nouns and a bit of grammar took more time than the typing, and I left out so much cool stuff! In the meantime, please send me your thoughts of people’s work besides your own. No press releases! No "I think scientists really need to consider “insert screed” Everything else, please send it on!)