Helping the blind see – mice that is

When I first saw the headline for this story I thought of the nursery rhyme about the three blind mice. Finally, they’ll be able to see the farmer’s wife coming at them with a carving knife. But the real-world implications are of this are actually pretty exciting.

Researchers at the National Institute of Health’s National Eye Institute took skin cells from mice and directly reprogrammed them into becoming light sensitizing cells in the eye, the kind that are often damaged and destroyed by diseases like macular degeneration or retinitis pigmentosa.

What’s particularly interesting about this is that it bypassed the induced pluripotent stem cell (iPSC) stage where researchers turn the skin cells into embryonic-like cells, then turn those into the cells found in the eye.

In a news release, Anand Swaroop of the NEI says this more direct approach has a number of advantages: “This is the first study to show that direct, chemical reprogramming can produce retinal-like cells, which gives us a new and faster strategy for developing therapies for age-related macular degeneration and other retinal disorders caused by the loss of photoreceptors.”

After converting the skin cells into cells called rod photoreceptors – the light sensing cells found in the back of the eye – the team transplanted them into blind mice. One month later they tested the mice to see if there had been any change in vision. There had; 43 percent of the mice reacted to light exposure, something they hadn’t done before.

Biraj Mahato, the study’s first author, said that three months later, the transplanted cells were still alive and functioning. “Even mice with severely advanced retinal degeneration, with little chance of having living photoreceptors remaining, responded to transplantation. Such findings suggest that the observed improvements were due to the lab-made photoreceptors rather than to an ancillary effect that supported the health of the host’s existing photoreceptors.”

Obviously there is a lot of work still to do before we can even begin to think about trying something like this in people. But this is certainly an encouraging start.

In the meantime, CIRM is funding a number of stem cell programs aimed at treating vision destroying diseases like macular degeneration and retinitis pigmentosa.

CIRM & NIH: a dynamic duo to advance stem cell therapies

NIH

National Institutes of Health

There’s nothing more flattering than to get an invitation, out of the blue, from someone you respect, and be told that they are interested in learning about the way you work, to see if it can help them improve the way they work.

That’s what happened to CIRM recently. I will let Randy Mills, who was our President & CEO at the time, pick up the story:

“Several weeks ago I got a call from the head of the National Heart. Lung and Blood Institute (NHLBI) asking would we be willing to come out to the National Institutes of Health (NIH) and talk about what we have been doing, the changes we have made and the impact they are having.”

Apparently people at the NIH had been reading our Strategic Plan and our Annual Report and had been hearing good things about us from many different individuals and organizations. We also heard that they had been motivated to engage more fully with the regenerative medicine community following the passage of the 21st Century Cures Act.

We were expecting a sit down chat with them but we got a lot more than that. They blocked out one and a half days for us so that we had the time to engage in some in-depth, thoughtful conversations about how to advance the field.

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Dr. Francis Collins, NIH Director

The meeting was kicked off by both Francis Collins, the NIH Director, and Gary Gibbons, the NHLBI Director. Then the CIRM team – Dr. Mills, Dr. Maria Millan, Gabe Thompson and James Harrison – gave a series of presentations providing an overview of how CIRM operates, including our vision and strategic priorities, our current portfolio, the lessons learned so far, our plans for the future and the challenges we face.

The audience included the various heads and representatives from the various NIH Institutes who posed a series of questions for us to answer, such as:

  • What criteria do we use to determine if a project is ready for a clinical trial?
  • How do we measure success?
  • How have our strategies and priorities changed under CIRM 2.0?
  • How well are those strategies working?

The conversation went so well that the one day of planned meetings were expanded to two. Maria Millan, now our interim President & CEO, gave an enthusiastic summary of the talks

“The meetings were extremely productive!  After meeting with Dr. Collins’ group and the broader institute, we had additional sit down meetings.   The NIH representatives reported that they received such enthusiastic responses from Institute heads that they extended the meeting into a second day. We met with with the National Institutes of Dental and Craniofacial Research, Heart, Lung and Blood, Eye Institute, Institute on Aging, Biomedical Imaging and Bioengineering, Diabetes, and Digestive and Kidney Diseases, and the National Center for Advancing Translational Sciences.  We covered strategic and operational considerations for funding the best science in the stem cell and regenerative medicine space.  We explored potential avenues to join forces and leverage the assets and programs of both organizations, to accelerate the development of regenerative medicine and stem cell treatments.”

This was just a first meeting but it laid the groundwork for what we hope will be a truly productive partnership. In fact, shortly after returning from Washington, D.C., CIRM was immediately invited to follow-up NIH workgroups and meetings.

As this budding partnership progresses we’ll let you know how it’s working out.

Stories that caught our eye: new target for killing leukemia cancer stem cells and stem cell vesicles halt glaucoma

New stem cell target for acute myeloid leukemia (Karen Ring).  A new treatment for acute myeloid leukemia, a type of blood cancer that turns bone marrow stem cells cancerous, could be in the works in the form of a cancer stem cell destroying antibody.

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Acute Myeloid Leukemia (Credit: Medscape)

Scientists from the NYU Langone Medical Center and the Memorial Sloan Kettering Cancer Center identified a protein called CD99 that appears more abundantly on the surface of abnormal blood cancer stem cells compared to healthy blood stem cells. They developed an antibody that specifically recognizes and kills the CD99 wielding cancer stem cells while leaving the healthy blood stem cells unharmed.

The CD99 antibody was effective at killing human AML stem cells in a dish and in mice that were transplanted with the same type of cancer stem cells. Further studies revealed that the CD99 antibody when attached to the surface of cancer stem cells, sets off a cascade of enzyme activity that causes these cells to die. These findings suggest that cancer stem cells express more CD99 as a protective mechanism against cell death.

In an interview with Genetic Engineering and Biotechnology News, Chris Park, senior author on the Science Translational Medicine study, explained the importance of their work:

“Our findings not only identify a new molecule expressed on stem cells that drive these human malignancies, but we also show that antibodies against this target can directly kill human AML stem cells. While we still have important details to work out, CD99 is likely to be an exploitable therapeutic target for most AML and MDS patients, and we are working urgently to finalize a therapy for human testing.”

While this work is still in the early stages, Dr. Park stressed that his team is actively working to translate their CD99 antibody therapy into clinical trials.

“With the appropriate support, we believe we can rapidly determine the best antibodies for use in patients, produce them at the quality needed to verify our results, and apply for permission to begin clinical trials.”

 

Peculiar stem cell function may help treat blindness (Todd Dubnicoff). Scientists at the National Eye Institute (NEI) have uncovered a novel function that stem cells use to carry out their healing powers and it may lead to therapies for glaucoma, the leading cause of blindness in United States. Reporting this week in Stem Cells Translational Medicine, the researchers show that stem cells send out regenerative signals by shedding tiny vesicles called exosomes. Once thought to be merely a garbage disposal system, exosomes are now recognized as an important means of communication between cells. As they bud off from the cells, the exosomes carry proteins and genetic material that can be absorbed by other cells.

Microscopy image shows exosomes (green) surrounding retinal ganglion cells (orange and yellow). Credit: Ben Mead

Microscopy image shows exosomes (green) surrounding retinal ganglion cells (orange and yellow). Credit: Ben Mead

The researchers at NEI isolated exosomes from bone marrow stem cells and injected them into the eyes of rats with glaucoma symptoms. Without treatment, these animals lose about 90 percent of their retinal ganglion cells, the cells responsible for forming the optic nerve and for sending visual information to the brain. With the exosome treatment, the rats only lost a third of the retinal ganglion cells. The team determined that microRNAs – small genetic molecules that can inhibit gene activity – inside the exosome were responsible for the effect.

Exosomes have some big advantages over stem cells when comes to developing and manufacturing therapies which lead author Ben Mead explains in a press release picked up by Eureka Alert:

“Exosomes can be purified, stored and precisely dosed in ways that stem cells cannot.”

We’ll definitely keep our eyes on this development. If these glaucoma studies continue to look promising it stands to reason that there would be exosome applications in many other diseases.