BioProject

Increasing evidence suggests that Long non-coding RNAs (LncRNAs) represent a new class of regulators of stem cells. More...

Increasing evidence suggests that Long non-coding RNAs (LncRNAs) represent a new class of regulators of stem cells. However, the roles of LncRNAs in stem cell maintenance and myogenesis remain largely unexamined. For this study, hundreds of novel intergenic LncRNAs were identified that are expressed in myoblasts and regulated during differentiation. One of these LncRNAs, termed LncMyoD, is encoded next to the Myod gene and is directly activated by MyoD during myoblast differentiation. Knockdown of LncMyoD strongly inhibits terminal muscle differentiation largely due to a failure to exit the cell cycle. LncMyoD directly binds to IGF2-mRNA-binding-protein 2 (IMP2) and negatively regulates IMP2-mediated translation of proliferation genes such as N-Ras and c-Myc. While the RNA sequence of LncMyoD is not well-conserved between human and mouse, its locus, gene structure and function is preserved. The MyoD-LncMyoD-IMP2 pathway elucidates a mechanism as to how MyoD blocks proliferation to create a permissive state for differentiation. In order to perform an unbiased search for downstream signaling pathways perturbed by LncMyodD downregulation, microarrays were performed on myoblasts treated with control vs LncMyoD shRNAs. Overall design: Total RNA was extracted using the TRIzol reagent (Invitrogen) and purified with Qiagen RNeasy separation columns (Qiagen) from myoblasts treated with control vs. LncMyoD shRNA. First-strand cDNA was synthesized and hybridized to GeneChip Mouse Genome 430 2.0 Array (Affymetrix). Less...