Identification of hematopoietic stem cell-specific miRNAs enables gene therapy of globoid cell leukodystrophy.

[krabbe disease]

Globoid cell leukodystrophy (GLD ; also known as Krabbe disease ) is an invariably fatal lysosomal storage disorder caused by mutations in the galactocerebrosidase (GALC ) gene . Hematopoietic stem cell (HSC )-based gene therapy is being explored for GLD ; however , we found that forced GALC expression was toxic to HSCs and early progenitors , highlighting the need for improved regulation of vector expression . We used a genetic reporter strategy based on lentiviral vectors to detect microRNA activity in hematopoietic cells at single -cell resolution . We report that miR-126 and miR-130 a were expressed in HSCs and early progenitors from both mice and humans , but not in differentiated progeny . Moreover , repopulating HSCs could be purified solely on the basis of miRNA expression , providing a new method relevant for human HSC isolation . By incorporating miR-126 target sequences into a GALC -expressing vector , we suppressed GALC expression in HSCs while maintaining robust expression in mature hematopoietic cells . This approach protected HSCs from GALC toxicity and allowed successful treatment of a mouse GLD model , providing a rationale to explore HSC-based gene therapy for GLD .