Stem cells in the news
....the biggest story in recent months was reported this week. It has to do with a much better way to harvest induced pluripotent stem cells
, iPSC, the cells that start out as a fully differentiated cell (a skin cell, for example) and are reverse-programmed to a primitive state; these cells appear to be nearly as pure and as full of potential as embryonic stem cells, but with less ethical uncertainly; there is no need for an embryo.
The process of rewinding a cell involves rebooting its genetic coding. Until now, this process was slow and rather inefficient. A group at the Weitzmann Institute in Israel reported in Nature that they found a way to increase iPSC yield 100 fold, and shortened the time this takes from four weeks to eight days. The paper is titled “Deterministic direct reprogramming of somatic cells to pluripotency
From a Weitzmann press release:
[Dr. Yaqub Hanna] and his group have identified the "brake" that holds back the production of stem cells, and found that releasing this brake can both synchronize the process and increase its efficiency from around one percent or less today to 100 percent. These findings may help facilitate the production of stem cells for medical use, as well as advancing our understanding of the mysterious process by which adult cells can revert back into their original, embryonic state.
Hanna and his group found that a specific protein was causing iPSC inefficiency. They showed that removing MBD3 from adult cells not only improves efficiency but greatly speeds the process; the time needed to produce the stem cells was shortened from four weeks to eight days.
Why this is significant: the iPSC field has exploded in recent years and opens up tremendous opportunities to develop therapies from patients’ own cells. There are many obstacles still to be overcome but this Israeli study will energize the field and move it much closer toward medical application of stem cells. Dr. Hanna notes that work was based on research into the natural pathways of embryonic development:
Scientists investigating reprogramming can benefit from a deeper understanding of how embryonic stem cells are produced in nature. After all, nature still makes them best, in the most efficient manner.
Neuralstem Chronic SCI Stem Cell Trial: Not Yet
No news. We reported last January
that Neuralstem got the green light for a trial of its line of neural stem cells (called NSI-566 and used for several years with apparent safety in a trial for ALS) for chronic spinal cord injury. In June, five centers were named to host the trial (Shepherd Center, Atlanta; University of Miami; Thomas Jefferson University Hospital in Philadelphia, and Wisconsin Medical College of Milwaukee; UC San Diego. From the company:
The primary objective of the trial, expected to commence in the third quarter of 2013, is to determine the safety and toxicity of human spinal stem cell transplantation for the treatment of paralysis and related symptoms due to chronic SCI. The secondary objectives of the study are to evaluate graft survival in the transplant site by MRI, as well as the effectiveness of transient immunosuppression.
The study will also look at several outcome measurements to assess functional recovery. Also from Neuralstem:
All patients in the trial will receive six injections in, or around, the injury site, using the same cells and procedure... The first four patients will receive 100,000 cells per injection; the second four patients will receive 200,000 cells per injection. All patients will also receive physical therapy post-surgery to guide newly formed nerves to their proper connections and functionality. The patients will also receive immunosuppressive therapy, which will be for three months, as tolerated.
StemCells, Inc. Goes for the Eyes
StemCells, Inc., as we have previously noted
, has a clinical trial ongoing in Switzerland to test the safety of a line of stem cells developed from fetal spinal cord tissue. From company literature: “The trial is designed to assess both safety and preliminary efficacy in patients with varying degrees of paralysis who are three to 12 months post-injury, and will progressively enroll patients based upon the severity of injury.”
There’s no news to report on that trial – the first three patients showed a measurable amount of sensory gain. The trial is still enrolling in Zurich (now dosing incomplete injurties) and soon, in Canada (no centers announced).
The company, however, just announced that these same stem cells (they call them HuCNS-SC) appear to help with a common eye disease. The cells preserve photoreceptor cells and visual function in an animal model of retinal degeneration. Says the company, “The surviving photoreceptors appear healthy and normal, and maintain their synaptic connection to other important cells necessary for visual function.... These results are highly relevant to disorders of vision loss, the most notable of which is age-related macular degeneration (AMD), which afflicts approximately 30 million people worldwide.”
The study was mainly done at the University of Alicante, Spain. From the paper
This study reveals the novel finding that preservation of specialized synaptic contacts between photoreceptors and second order neurons as well as phagocytosis of photoreceptor outer segments are potential mechanism(s) of HuCNS-SC transplantation, mediating functional rescue in retinal degeneration.
StemCells, Inc. is now enrolling AMD patients at the Byers Eye Institute at Stanford in Palo Alto, CA, and at the Retina Foundation of the Southwest in Dallas. To date, five patients have been dosed in the 16-patient trial.