Distinct repertoires of microRNAs present in mouse astrocytes compared to astrocyte-secreted exosomes

• Published in: PloS one Vol. 12; no. 2; p. e0171418
• Main Authors: Jovičić, Ana, Gitler, Aaron D.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 02.02.2017; Public Library of Science (PLoS)
• Subjects: Amyotrophic lateral sclerosis; Animals; Astrocytes; Astrocytes - metabolism; Biology; Biology and life sciences; Blotting, Western; Brain research; Cells, Cultured; Central nervous system; Exosomes; Exosomes - metabolism; Female; Gene expression; Gene Expression Regulation; Gene regulation; Genes; Male; Mice; MicroRNA; MicroRNAs; MicroRNAs - metabolism; miRNA; Motor Neurons - metabolism; Neural networks; Neurodegenerative diseases; Neurosciences; Polymerase Chain Reaction; Regulation; Research and Analysis Methods; Schizophrenia; Secretion; Stem cells; Superoxide dismutase; Transcriptome; Transmission electron microscopy; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0171418

Astrocytes are the most abundant cell type in the central nervous system (CNS) and secrete various factors that regulate neuron development, function and connectivity. microRNAs (miRNAs) are small regulatory RNAs involved in posttranslational gene regulation. Recent findings showed that miRNAs are exchanged between cells via nanovesicles called exosomes. In this study, we sought to define which miRNAs are contained within exosomes secreted by astrocytes. We also explored whether astroglial miRNA secretion via exosomes is perturbed in a mouse model of amyotrophic lateral sclerosis (ALS), a neurodegenerative disease where astrocytes play a crucial role in driving disease progression. By isolating and profiling the expression of miRNAs from primary mouse astrocytes and from the exosomes that astrocytes secrete, we compared miRNA expression in the cells and secreted vesicles. We established that miRNA expression profiles of astrocytes and their exosomes are vastly different. In addition, we determined that exosomal miRNA expression in astrocytes is not significantly perturbed in a mouse model of ALS. Astrocytes secrete numerous miRNAs via exosomes and miRNA species contained in exosomes are considerably different from miRNAs detectable in astrocytes, suggesting the existence of a mechanism to select certain miRNAs for inclusion or exclusion from exosomes. The exosomal miRNA profiling dataset we have generated will provide a resource to aid in the investigation of this selection mechanism. Finally, the miRNA expression profile in astrocyte-secreted exosomes is not perturbed by expression of mutant SOD1-G93A.