Tubastatin A maintains skeletal muscle stem cell (MuSC) quiescence

We show that Tubastatin A (TubA) preserves MuSC quiescence and stem cell potency ex vivo, by inhibiting HDAC6 and, consequently, primary cilium resorption. Treatment with TubA improves MuSC engraftment potential and induces a return to quiescence in cycling MuSCs, revealing a potentially valuable approach to enhancing the therapeutic potential of MuSCs. To examine the state of quiescence preserved by TubA at the transcriptome level, we performed RNA-Seq and we found that TubA-treated MuSCs exhibit a quiescent transcriptome. The molecular mechanisms involved in the maintenance of quiescence by TubA were ribosome- and oxidative phosphorylation-related genes as well as low expression levels of cell cycle genes and Hh signaling genes. Overall design: Young C57BL/6 male mice were used. Quiescent muscle stem cells were isolated from limb muscles by FACS (CD45- CD31- Sca1- VCAM+) and either immediately used for analysis or cultured ex vivo for 24h in the presence or abscence of Tubastatin A. Each replicate represents the muscle stem cells from a single animal. There are 4 replicates for Tubastatin A-treated cells and 3 replicates in the other two conditions.