Alejandro La Greca , María Agustina Scarafía , María Clara Hernández Cañás , Nelba Pérez , Sheila Castañeda , Carolina Colli , Alan Miqueas Möbbs , Natalia Lucía Santín Velazque , Gabriel Neiman , Ximena Garate , Cyntia Aban , Ariel Waisman , Lucía Moro , Gustavo Sevlever , Carlos Luzzani , Santiago Miriuka
May 24 2019
PIWI-interacting RNAs (piRNAs) are a class of non-coding RNAs initially thought to be restricted almost exclusively to germ line cells. In recent years, accumulating evidence has demonstrated that piRNAs are actually expressed in somatic cells like pluripotent, neural, cardiac and even cancer cells. However, controversy still remains around the existence and function of somatic piRNAs. Using small RNA-seq samples from H9 pluripotent stem cells differentiated to mesoderm progenitors and cardiomyocytes we identified the expression of 447 piRNAs, of which 241 were detected in pluripotency, 218 in mesoderm and 171 in cardiac cells. The majority of them originated from the sense strand of protein coding and lncRNAs genes in all stages of differentiation, though no evidences for secondary piRNAs (ping-pong loop) were found. Genes hosting piRNAs in cardiac samples were related to critical biological processes in the heart, like contraction and cardiac muscle development. Our results indicate that somatic piRNAs might have a role in fine-tuning the expression of genes involved in the differentiation of pluripotent cells to cardiomyocytes.