A long non-coding RNAGATA6-AS1adjacent toGATA6is required for cardiomyocyte differentiation from human pluripotent stem cells

Long noncoding RNAs (lncRNAs) are crucial in many cellular processes, yet relatively few have been shown to regulate human cardiomyocyte differentiation. Here, we demonstrate an essential role of GATA6 antisense RNA 1 (GATA6-AS1)in cardiomyocyte differentiation from human pluripotent stem cells (hPSCs).GATA6-AS1is adjacent to cardiac transcription factorGATA6. We found thatGATA6-AS1was nuclear-localized and transiently upregulated along withGATA6during the early stage of cardiomyocyte differentiation. The knockdown ofGATA6-AS1did not affect undifferentiated cell pluripotency but inhibited cardiomyocyte differentiation, as indicated by no or few beating cardiomyocytes and reduced expression of cardiomyocyte-specific proteins. Upon cardiac induction, the knockdown ofGATA6-AS1decreasedGATA6expression, altered Wnt-signaling gene expression, and reduced mesoderm development. Further characterization of the intergenic region between genomic regions ofGATA6-AS1andGATA6indicated that the expression ofGATA6-AS1andGATA6were regulated by a bidirectional promoter within the intergenic region. Consistently,GATA6-AS1andGATA6were co-expressed in several human tissues including the heart, similar to the mirror expression pattern ofGATA6-AS1andGATA6during cardiomyocyte differentiation. Overall, these findings reveal a previously unrecognized and functional role of lncRNAGATA6-AS1in controlling human cardiomyocyte differentiation.