In this week's Science, a team of researchers from industry and academia report on how the deletion of a single microRNA from pluripotent stem cells enabled them to form both embryonic and non-embryonic lineages, revealing a role for the small, non-coding RNAs in regulating pluripotency. Specifically, when miR-34a was eliminated from embryonic stem cells, these engineered cells were able to generate both embryonic and extra-embryonic lineages. Cells deficient in miR-34a also exhibited elevated expression of a retrovirus known as MuERV-L endogenous retrovirus.
And in Science Translational Medicine, investigators from the National Institutes of Health and Leidos Biomedical Research publish a study showing how CRISPR/Cas9 genome editing can be used to correct a rare immunodeficiency disorder. The researchers used CRISPR to repair in stem cells a mutation in the gene NOX2 that causes chronic granulomatous disease — a condition that increases patient susceptibility to certain infections — and confirmed that the engineered cells differentiate into immune cells with restored antimicrobial function. When the cells were implanted in mice, the pool of altered cells maintained their gene edits long-term with no apparent side effects. GenomeWeb has more on this, here.