In this study, we have addressed the role of the imprinted long non-coding RNA (lncRNA) Meg3 and its associated miRNA cluster for adult hematopoietic stem cell (HSC) function. Meg3 is highly and specifically expressed in adult HSCs, but not in progenitor or mature cells. HI-STEM PhD student Pia Sommerkamp and her colleagues could show that targeted Meg3-deletion surprisingly does not impair HSC function or hematopoiesis. The effects of Meg3 deficiency were not only analyzed under homeostatic conditions, but also in response to inflammatory signaling and in in vivo serial reconstitution assays. Within the study, the team has shown that loss of Meg3 expression in HSCs in adult mice as well as in the embryonic stage does not affect the hematopoietic system. These results challenge a recent report and suggest that the Meg3 locus only indirectly affects HSC function by modulating the microenvironment or niches of HSCs.

The work was co-supervised by Andreas Trumpp from HI-STEM and Nina Cabezas-Wallscheid from the Max Planck Institute of Immunobiology and was published in Scientific Reports.

 Further Reading:

• Sommerkamp, P., Renders, S., Ladel, L., Hotz-Wagenblatt, A., Schönberger, K., Zeisberger, P., Przybylla, A., Sohn, M., Zhou, Y., Klibanski, A., Cabezas-Wallscheid, N.^@, & Trumpp, A.^@ (2019). The long non-coding RNA Meg3 is dispensable for hematopoietic stem cells. Scientific Reports, 9(1), 2110. doi: 10.1038/s41598-019-38605-8