Donor stem cells likely best for treating vision loss caused by diabetic retinopathy
Researchers from The University of Virginia School of Medicine (VA, USA) have concluded that cells taken from non-diabetic donors will probably be more effective at treating diabetic blindness than autologous patient cells.
Diabetes, a condition increasing in incidence, commonly causes an eye disease known as diabetic retinopathy (DR). If left untreated DR can cause blindness – high blood glucose levels damage the blood vessels supplying the retina. Furthermore, despite more than 100 million individuals being estimated to suffer from DR and related conditions, there are limited treatment options. Current treatments either destroy a significant proportion of the retina with a laser or require patients to receive injections directly into their eyeball up to once a month for the rest of their lives.
“There’s huge room for improvement on the standard of care, and the number of patients in this demographic is increasing by the day, dramatically, so the need is only going up,” says Dr Shayn M Peirce, from the University of Virginia (VA, USA) Department of Biomedical Engineering. “So I think there are three pieces working together – the University of Virginia’s strengths in this area, the US FDA’s encouragement [of stem cell research in the eye] and the clinical realities – to drive this cell-based therapy toward the clinic.”
Researchers from The University of Virginia School of Medicine had previously demonstrated that an intravitreal injection of adipose-derived stem cells (ASCs) could stabilize the retinal microvasculature, enabling repair and regeneration of damaged capillary beds in vivo. In the present study they aimed to investigate the best source of adult stem cells (fat-derived stem cells gathered during liposuction procedures) to inject into patients’ eyes to halt or reverse the loss of vision that occurs in DR.
They used the hyperglycemic Akimba mouse as a model of DR, with mice receiving intravitreal injections of ASC-conditioned media or ASCs themselves. Conditioned medium was less vasoprotective than injected ASCs, and diabetic ASCs secreted less vasoprotective factors than healthy ASCs. The findings therefore confirmed that cells taken from non-diabetic donors will likely be more successful for treating DR than cells taken from patients’ own bodies, as the donor’s own cells are functionally impaired.
“It answers a vital question: If we’re going to carry this therapy forward into clinical trials, where are we going to get the best bang for the buck?” explained University of Virginia researcher and ophthalmologist Dr Paul Yates. “The answer seems to be, probably, taking cells from patients who aren’t diabetic. Because the diabetic stem cells don’t seem to work quite as well. And that’s not terribly surprising, because we already know that this cell type is damaged by diabetes.”
Peirce also comments, “We now know what to look for when we harvest a patient’s cells, because we know what distinguishes good quality cells from poor quality… We almost have a screen to determine quality control. We’re essentially establishing quality-control criteria by understanding what works and why.”
The team hopes to begin human clinical trials within the next few years. “This is not science fiction at all,” Yates said. “The idea that you can take cells from somewhere else and inject them into the eye to treat disease is here today.”
Source: Cronka SM, Kelly-Gossa MR, Clifton Raya H et al. Adipose-derived stem cells from diabetic mice show impaired vascular stabilization in a murine model of diabetic retinopathy. Stem Cells Trans. Med. 4(5), 459–467 (2015); http://newsroom.uvahealth.com/about/news-room/diabetic-blindness-uva-ids-best-source-of-stem-cells-to-battle-vision-loss.