Archive by category | Conference blogs

ISSCR 2009 meeting: what’s changed from last year?

I asked that question over and over. Common responses were that discussions of iPS cells were less prominent (except at the poster sessions) and talks about tissue-specific stem cells more so. People I spoke with generally felt there was greater variety in topics and presenters than they’d seen before; though at least one felt there was an over-reliance on “ISSCR’s established speakers.” Several thought the meeting, which at around 3,100 attendees was the biggest yet, was growing too large, making attendance a good way to get an overview of related specialties and network, but not as effective for keeping up in one’s own field. General consensus was that most talks described recently published or accepted work. There was a lot of new content in two very jam-packed poster sessions, together exhibiting well over 1000 posters (the numbers went into the 1750s!)  … Read more

ISSCR sessions from Barrandon and Mikkola: thymus makes skin, SCL starts up HSCs

Note: These accounts of talks given at ISSCR were written by Andrea Ditadi. Yann Barrandon: Thymus cells make skin, hair follicles The skin, vagina, cornea, esophagus and other organs in contact with external environment, no matter their germ layer of origin, are all covered with stratified epithelium. Such epithelium is characterized by cells that undergo constant self-renewal. Yann Barrandon of Lausanne University Medical School reported some years ago that this long-term renewal was due to a population of multipotent, clonogenic stem cells. (Claudinot et al 2005, PNAS). These cells persist in niches and proliferate according to environmental cues. In vitro,  … Read more

Business round-up: pluripotent products, all-star academics and headlines everywhere

Academic all-stars from the East and West Coasts of the US have united to advise a company with plans to use induced pluripotent stem (iPS) cells to find drugs. The company, created from the merger of Boston-based Perian and San Francisco-based iZumi, will be called iPierian and run by iZumi CEO John Walker from San Francisco.  Read more

ISSCR plenaries: how to repair 1) a salamander leg and 2) a human airway

NOTE: These two write-ups are by Teisha Rowland, a volunteer Niche blogger and student at UC Santa Barbara. Limb regeneration takes nerve Proper limb regeneration in the salamander requires the presence and function of nerves, although it is unclear why this is on a molecular level. Recent evidence implicates a newly discovered protein as having a central role in the innervation of regenerating limbs. At ISSCR in Barcelona, Jeremy Brockes of the University College London reported that in severed salamander limbs the protein n(ewt)AG, or nAG, is key for promoting regeneration. nAG production, in turn, is linked to nerves in  … Read more

ISSCR posters: In vitro stem cell culture: are we doing enough to make the cells feel at home?

This account is by Julie Clark, a Field Application Scientist at Stemgent in San Diego. Some five dozen abstracts published for ISSCR this year included the word “oxygen”. Each highlighted the benefits of low oxygen (0.2-10% O2) for embryonic, hematopoietic, and mesenchymal stem cell culture. Indeed a steady stream of publications describes how hypoxia inducible factors and reactive oxygen species affect stem cell self-renewal and differentiation. This makes scientists wonder what might be missing in standard in vitro culture conditions. A discussion with Jit Hin Tan from MIT highlighted the need for continuous hypoxia: Oxygen diffuses from the media surface  … Read more

Why Yamanaka’s new results don’t (necessarily) spell doom for most human iPS cells

The stem cell field needs developmental biologists not just to use iPS cells, but to pick the best ones. As Shinya Yamanaka finished his talk Saturday morning, I literally felt cold. He’d compared dozens of mouse ES cell lines with iPS cell lines generated from mouse embryonic fibroblasts, tail tip fibroblasts (TTFs), hepatocytes, and even a few lines from stomach tissue. The tail-tip fibroblasts were bad news: they resisted differentiation. Even after in vitro differentiation caused the cells to make neurospheres twice, tail tip fibroblasts injected into mouse brains did not persist calmly as brain cells but instead made big, scary teratomas. Other assays came to similar conclusions. Of course, not every line misbehaved, but the TTF lines were much more likely to do so than the others. (You can read more of the results in Nature Biotechnology )  … Read more