There's Hope Out There

Stem Cell research is just amazing and hopefully in the near future it will get to the point where they can make human organs which still has quite a way to go.

Stem Cell Transplants Restore Vision in Mice
By Michael Smith, North American Correspondent, MedPage Today
Published: April 09, 2009
Reviewed by Dori F. Zaleznik, MD; Associate Clinical Professor of Medicine, Harvard Medical School, Boston
TORONTO, April 9 -- The three blind mice might have avoided the farmer's wife and her tail-chopping knife -- if they had been given a corneal stem cell transplant.
Action Points Researchers at the University of Pittsburgh School of Medicine are reporting that mice with scarred and hazy corneas can have their vision restored with a transplant of human corneal stem cells. The findings suggest that cell-based therapies might be an effective way to treat human corneal blindness and vision impairment caused by infection, trauma and other common eye problems, according to James Funderburgh, Ph.D., and colleagues. "Our experiments indicate that after stem cell treatment, mouse eyes that initially had corneal defects looked no different than mouse eyes that had never been damaged," Dr. Funderburgh said in a statement.
In addition, the researchers wrote online in the journal Stem Cells, the cells have an "immune privileged status" that results in rejection of only about 10% of allografts, making their practical application less complicated than it might be in other tissues. One implication, they said, is that the ability to grow millions of stem cells in the lab might allow an off-the-shelf product useful in countries with a high burden of eye disease but limited medical resources. Dr. Funderburgh and colleagues reported in 2005 that they had isolated stems cells from human corneas that retained the ability to produce stromal matrix after expansion in vitro.
In the current study, the researchers tested the cells to see their effect on mice genetically engineered to lack a protein -- lumican -- that plays a key role in maintaining the transparency of corneas. Preliminary experiments showed that 88% of injected stem cells remained viable after 10 weeks, secreting extracellular matrix components characteristic of human corneal stroma. In 14-week-old lumican-negative mice, electron microscope examination of the eyes showed a distinct population of large abnormal fused fibrils in the posterior stroma. But 12 weeks after injection of the stem cells, the eyes showed normal fibrils in both the posterior and anterior stroma -- similar to those seen in littermates that possessed the gene for lumican.
Without treatment, the corneas of lumican-negative mice are significantly hazier and thinner (at P<0.001 for both comparisons) than those of normal animals, the researchers noted. But the animals given stem cell injections had stromal thickness that was indistinguishable from wild type control corneas -- 102 micrometers versus 107 -- and was significantly different (at P<0.001) than untreated corneas from lumican-negative animals. Similarly, haze in the recipient lumican-negative corneas was restored to the range of wild type corneas -- 59% versus 62% -- and was significantly different (also at P<0.001) from the 93% seen in untreated lumican-negative mice. The researchers noted that mouse corneas differ from those of humans in two important aspects -- they are thinner and possibly easier to treat with stem cells, and they are less cross-linked than human tissue, which is tougher and more stable. Nonetheless, the findings "provide a new paradigm demonstrating unequivocally that a stem cell-based therapy in some form can provide a powerful approach to treatment for corneal opacity, a major cause of blindness," the researchers concluded. The study was supported by the NIH, the Eye and Ear Foundation (Pittsburgh), and Research to Prevent Blindness. The researchers reported no conflicts.
Primary source: Stem Cells
Source reference:
Du Y, et al "Stem cell therapy restores transparency to defective murine corneas" Stem Cells 2009