Identification, stability and expression of Sirt1 antisense long non-coding RNA

Natural antisense transcripts (NATs) exist ubiquitously as pivotal molecules to regulate coding gene expression. Sirtuin 1 (Sirt1) is a NAD-dependent deacetylase which is involved in myogenesis. However, whether Sirtl transcribes NAT during C2C12 differentiation is still unknown. In this study, we identified a Sirt1 NAT which was designated as Sirt1 antisense long non-coding RNA (AS IncRNA) by sequencing and bioinformatic analysis. The level of Sirt1 AS IncRNA was greater in spleen but less in muscle tissue. The expression of both Sirt1 mRNA and Sirt1 AS lncRNA decreased during C2C12 myogenic differentiation, whereas the levels of miR-34a, which targets Sirtl, increased gradually. We further found that the half-life of Sirt1 AS IncRNA was 10 h, but that of Sirt1 mRNA was 6 h in C2C12 cells treated with 2 mu g/ml Actinomycin D. Therefore, compared with Sirtl mRNA, Sirt1 AS IncRNA was more stable. Overexpression of Sirt1 AS IncRNA increased the levels of Sirt1 protein, whereas overexpression of Sirt1 AS IncRNA mutant did not affect the level of Sirt1 protein in C2C12 cells. Moreover, downregulation of Sirt1 mRNA caused by miR-34a was counteracted by Sirtl AS IncRNA in C2C12 cells. Taken together, we identified a novel NAT of Sirtl which implicated in myogenesis through regulating Sirtl expression. (C) 2014 Elsevier B.V. All rights reserved.