Highlights from the ISSCR – 2
Sensory and intellectual overload
Conferences are fun that way but I always want to try to suck out all the marrow. Although with what I learned about the crucial role for adipocytes in the maintenance of the hematopoeitic stem cell nice, I’ll leave that marrow where it is (besides, yuk for the texture).
Breakfast with the big brains
A couple of hundred people were gathered at round, wedding-banquet-style tables, with bagels, coffee, juice and one big name per table. Thomas Graf graciously presided ours. He made the rounds, struck up conversations with everyone. We were a typically diverse cross-section of attendees – 20% of us were working in our country of origin, and we covered eight countries among us. There was the requisite stalker grad student looking to get himself a postdoctoral position, but it is a time-honored role and no one begrudged him the effort. What I learned is that Thomas at least believes that it is very important to distinguish between the dedifferentiation or (epigenetic) reprogramming of induced pluripotent stem cells, and the transdifferentiation that he has published for blood cells and that Doug Melton discussed yesterday for the pancreas. So be it. It was a good initiative, making this nearly 3000-delegate conference more intimate, like (saith attendees of said conferences) the Keystone symposia.
Posters
This is where the stuff that has not yet been published usually appears. Sometimes, with advances relative to when the abstract was submitted. I visited a good number, but here are the ones I found particularly interesting.
Paulette Conget presented “Correction of recessive dystrophic epidermolysis bullosa by local implantation of allogeneic mesenchymal stem cells”. I went to this poster because I have colleagues working on this disease, in particular on gene therapy for it, since the skin blisters horribly due to a mutation in the collagen VII gene. It needs replacement under the top layer of the skin. Conget and colleagues isolated mesenchymal stem cells (MSC) from a 16-year old female donor, expanded them in culture under conditions I had no time to note, and saved them in the freezer. Then they treated a severely affected, 25-year-old female patient affected with epidermolysis bullosa (homozygous c.7708delG mutations) by injecting half-a-million MSC into both intact and widely ulcerated parts of her skin. I’m a little curious about the ethical part of the treatment if anything went wrong (eg. if she ended up with a basal cell carcinoma instead of the good effect they report). In any case, after a week, they took punch biopsies from intact treated/untreated and blistered treated/untreated sites. In the case of the blistered, treated areas, they found new collagen VII production between the epidermis and dermis. After three weeks, new epithelia was growing over the ulcers, and this epidermis adhered to the underlying dermis. After seven months, the patient is still improved. Apparently the MSC do not elicit an immune response, although they took care to find an allogeneic donor.
Roozbeh Golshani kindly shared with me his experience as to which of the commercially available versions of the antibody against human-specific nuclear antigen is truly effective in his hands after xenografting. The kind of information you can only get live in front of the poster from the person who did the experiments. Thanks, Roozbeh!
Raja Kittappa, from Ron McKay’s laboratory, spent a long time talking with me about his poster based on his recent paper, entitled here “The floor plate gene, Foxa2, is required for the generation and maintenance of midbrain dopamine neurons”. In older mice with a mutation in one of the two alleles of this gene, they develop signs of Parkinson’s disease (due to loss of dopaminergic neurons). The gene locus is linked to human PD as well on chromosome 20p11, although at a distance of approximately 150kb from the coding portion of the gene. Collaborators of theirs at Boston University are working on this aspect. Things I would never have connected if I had not spoken with the poster presenter.
Plenary and concurrent sessions
I fully intended to not get interested in the plenary talks this morning, dedicated to the clinical translation of stem cell research. I wanted to go spend time in front of the posters. However, they didn’t open the poster/exhibit hall until 11AM, which meant that I may as well attend the plenary session. And of course I found the talks interesting. But I spent some of my concentration capital.
Later on, I sat next to a young man taking notes on his computer on what appeared to be a webpage. I asked him what lab management software he used. It’s open source, quoth he, and he wrote down the website that provides it. Unfortunately, I didn’t take down his name as I have no idea to get from here to there. And I already work with a wiki and don’t find the markup so straightforward as that.
Running between two concurrent sessions between which my interest was equally divided, I started with Jeff Biernaskie, from Freda Miller’s group, presenting what appears to be as yet unpublished work about dermal “skin precursors“. What I liked is that if they isolate them from rats and transplant them into mice, the mouse hair follicles work overtime and take on rat-like length and coarseness, leading to a big long tuft of hair after three weeks.
Then Maksim Plikus from Cheng-Ming Chuong’s group presented a fabulous story to which I won’t be able to do justice, as I am yawning uncontrollably. This has been published and is kindly provided in full text from the lab website. I want to read the article, but meanwhile, the press release states succinctly:
The research team found that hairs, even in normal mice, regenerate in waves, rather than individually. The findings suggest that hair stem cells are regulated not only by the micro-environment within one hair follicle—as has previously been thought—but also by adjacent hair follicles, other skin compartments and systemic hormones, in a hierarchical order.
We ladies who have had babies remember that we retain our hair longer, so it seems longer and thicker, and then it all falls out again after the baby is born. Mice do the same. That’s the systemic hormone thing. What really caught my imagination is that subcutaneous fat as well as the dermis (cf. Biernaskie) coordinate the regenerative ability of large sectors of hair follicles.
It makes me think of the unsupported observation I’ve made for a while that often you find a thick, beautiful head of hair on a well-endowed woman. And that storing up fat for the winter in hibernating animals definitely corresponds with growing longer, thicker fur; when the animal awakes and is active and hungry in the spring, the hair falls out. Do short-haired cat breeds make less BMP2/4 in the skin or subcutaneous compartments than do angora breeds?
Posted on Thursday, June 12th, 2008 at 10:15 pm Categorized as:development, general science, laboratory You can leave a response, or trackback from your own site.
