Friday, April 19, 2013

Stem cell Stories that caught our eye: arthritis therapy, replacement kidneys and trachea transplants

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun. 

Lab grown kidney works. Given events in Boston this week, it seems fitting to start with a story about work by my old colleagues at Massachusetts General Hospital. Prior to the horrific injuries from the marathon bombings Monday, they had some great news that made most major news outlets Sunday afternoon and Monday morning (here's a link to the Boston Globe story). The MGH team started with a donor rat kidney, stripped away its soft tissues so that only a collagen matrix remained. They then seeded that structure with stem cells, carefully nurtured it in special lab conditions, and then implanted it into a rat where it was able to produce urine. (I wrote this last night, only to wake up this morning to all my friends from Boston posting about being on lock down. We are hoping for a safe and fast resolution to this horrible situation.)

Placenta stem cells sent to heal wounds in Boston. After growing up in rural Indiana it was nice to see this article about a hospital 90 miles from my hometown organizing new mothers to donate placenta fluid to ship to hospitals in Boston. The various adult stem cells found in the placenta have been shown in some still experimental studies to speed the healing of wounds. We don’t know if and how the Boston hospitals will use these Hoosier cells. Here's more about the program.

Stem cells deliver drug to arthritic joints. I am always drawn to articles that discuss using stem cells for something other than replacing tissue. Their ability to do many different things is too often overlooked. In this case, a team at the biotech company Osiris used mesenchymal stem cells to deliver a drug to the joints of mice with a disease that resembles rheumatoid arthritis. Patients with this debilitating disease make too much of a protein that causes inflammation. That protein can be blocked by a drug marketed as Enbrel, but when you deliver the drug systemically, you have to give such a high dose to get enough into the joints that you cause major side effects. The team engineered the mesenchymal stem cells so that they could deliver the drug, and since stem cells naturally home to inflammation, the drug was delivered where it was needed. They did see faster relief from the arthritis but they could not measure the side effects in the mouse model. They published the work in the journal Stem Cells Translational Medicine.

Developing a better way to get personalized cells. When this year’s Nobel Prize winner Shinya Yamanaka revealed that he had created stem cells from a person’s skin the entire field leaped to work hoping to use the technology to create stem cells that could produce replacement tissue that would not be rejected by a person’s immune system. Five years later, as is usually the case in science, this promise has yet to be fully realized. One of the biggest obstacles is that the genetic factors Yamanaka used to reprogram the adult cells are not very efficient. The process generally takes two months and yields a mixed soup of cells, with few fully reprogrammed stem cells. Many teams have reported results improving this efficiency, and one of the most promising is the work of CIRM-funded Sheng Ding at Gladstone Institutes. Here Forbes offers a detailed explanation of his attempt to do the reprogramming with small molecules.

Report provides a snap shot of the status of the field. The Alliance for Regenerative Medicine, an advocacy organization for which CIRM was a founding member, has issued an annual report that provides a valuable overview of where the field is going and its progress in the clinic. If your interest is directed to a particular disease, beginning on page 30 the group provides clinical progress for a number of diseases.

What have the trachea transplants really accomplished. Everyone was impressed when the first reports came out that stem cells had been placed on scaffolds and result in a trachea that could be transplanted successfully into patients. Teams have now done 15 of these procedures, but we do not yet know if these transplants are a temporary fix or if they might last the regular lifetime of the patients. This detailed piece in the journal Science gives a great recount of the history and quotes our president Alan Trounson on the unknowns. Don’t be shied away because it is in a scientific journal. It is in the upfront news section and is written quite clearly, something I can say with pride since the author, Gretchen Vogel, was an intern with me many years ago.

New science museum has expanded stem cell exhibit. As a science junky I have to give a shout out to the new Exploratorium. The venerable and groundbreaking San Francisco hands-on science museum has moved from the Palace of Fine Arts to two adjoining piers on the downtown waterfront where it has twice the space. The stem cells that had been in residence in the old facility have now been joined by some added materials on our field. Here's more about the move.

D.G.

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