At the International Society for Stem Cell Research meeting in Toronto last week, the who’s who of the field gathered to discuss the latest advances, but they probably missed a milestone: On 9 June, the US National Institutes of Health (NIH) added the hundredth embryonic stem (ES) cell line to its registry of those that are eligible for taxpayer-backed funding.
Importantly, the newly added stem cells include several ES cells derived from people with heritable genetic diseases. As such, the newly fundable lines should allow scientists to perform ‘disease in a dish’ experiments and hopefully discover new therapeutic options.
Until this year, just one approved cell line — for a rare connective tissue disease called Marfan syndrome — was explicitly disease-specific. Dozens others had been up for consideration. But they ran into trouble a year ago, when the NIH rejected 42 ES cell lines carrying mutations for a wide range of diseases after an advisory panel ruled that the consent forms provided to the embryo donors were not up to snuff.
Things started to change in March when two cell lines from Harvard University’s ES cell collection got the NIH go-ahead. Both contained mutations for muscle degeneration diseases — one for spinal muscular atrophy, while the other for Duchenne muscular dystrophy.
Since the beginning of the month, the NIH has quietly kept adding ES cell lines to its registry, bringing the total tally up to 128. The latest additions include the first such cell lines derived under good manufacturing practices guidelines for human clinical use, plus several related to disease models: two are affected by Charcot-Marie-Tooth disease, an inherited neurological disorder, and three lines carry at least one mutation linked to congenital nephrotic syndrome, a disease characterized by protein in the urine and swelling of limbs.
“There is no doubt that reprogrammed neurons from human ES cells will facilitate work on the mechanism of neurological disease, permitting analysis of molecular mechanisms and testing drug effects that might stabilize unstable proteins,” Miriam Meisler, a geneticist at the University of Michigan who earlier this month reported a mouse model of Charcot-Marie-Tooth disease, wrote in an email.
Some of the diseased cell lines, however, come with caveats. For instance, NIH-funded research involving the ES cells with the congenital nephrotic syndrome defect must follow the language of the informed consent document at New Jersey’s Reprogenetics, a preimplantation genetic diagnosis company that derived the cells. The consent forms limit use of the cells to characterizing genetic and developmental defects or studying new methods for cell differentiation.
As such, Sumant Chugh, a kidney disease researcher at the University of Alabama at Birmingham, says “it would be useful to have stem cell lines from multiple depositing agencies” to work around such restrictions.