Guella, G. | bioRxiv Science

bioRxiv2018

Lipid utilization in skeletal muscle cells is modulated in vitro and in vivo by specific miRNAs

Skeletal muscle is composed by different myofiber types that can preferentially use glycolysis or lipids for ATP production. How fuel preference is specified in these post-mitotic cells is unknown. Here we show that miRNAs are important players in defining the myofiber metabolic profile. mRNA and miRNA signatures of all myofiber types obtained at single cell level unveiled fiber-specific regulatory networks and identified two master miRNAs that coordinately control myofiber fuel preference and mitochondrial morphology. Our work provides a complete and integrated myofiber type-specific catalogue of genes and miRNAs expressed and establishes miR-27a-3p and miR-142-3p as key regulators of lipid utilization in skeletal muscle.\n\nHIGHLIGHTSO_LITranscriptional networking in single cells distinguished myofibers based on glycolytic or oxidative metabolism, regulated by specific miRNAs\nC_LIO_LImiR-27a-3p and -142-3p influence mitochondrial morphology\nC_LIO_LImiR-27a-3p improves lipid utilization and increases glycogen storage both in vitro and in vivo\nC_LIO_LImiR-142-3p reduces lipid utilization both in vitro and in vivo\nC_LI

genomics↗

bioRxiv2017

Active ribosome profiling with RiboLace

Ribosome profiling, or Ribo-Seq, is based around large-scale sequencing of RNA fragments protected from nuclease digestion by ribosomes. Thanks to its unique ability to provide positional information concerning ribosomes flowing along transcripts, this method can be used to shed light on mechanistic aspects of translation. However, current Ribo-Seq approaches lack the ability to distinguish between fragments protected by ribosomes in active translation or by inactive ribosomes. To overcome these significant limitation, we developed RiboLace: a novel method based on an original puromycin-containing molecule capable of isolating active ribosomes by means of an antibody-free and tag-free pull-down approach. RiboLace is fast, works reliably with low amounts of input material, and can be easily and rapidly applied both in vitro and in vivo, thereby generating a global snapshot of active ribosome footprints at single nucleotide resolution.

molecular biology↗