Changes in microRNA expression in the whole hippocampus and hippocampal synaptoneurosome fraction following pilocarpine induced status epilepticus

• Published in: PloS one Vol. 8; no. 1; p. e53464
• Main Authors: Risbud, Rashmi M, Porter, Brenda E
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 07.01.2013; Public Library of Science (PLoS)
• Subjects: Animals; Biology; Brain; Control; Disease control; Enrichment; Epilepsy; Gene expression; Gene Expression Regulation; Head injuries; Hippocampus; Hippocampus - metabolism; Hippocampus - pathology; Hospitals; Kinases; Laboratory animals; Medicine; Microarray Analysis; MicroRNA; MicroRNAs; MicroRNAs - genetics; MicroRNAs - metabolism; miRNA; mRNA; Nervous system; Neurology; Pediatrics; Pilocarpine; Protein binding; Protein Biosynthesis; Protein synthesis; Proteins; Rats; Rats, Sprague-Dawley; Ribonucleic acid; RNA; RNA, Messenger - genetics; RNA, Messenger - metabolism; Rodents; Status epilepticus; Status Epilepticus - chemically induced; Status Epilepticus - genetics; Status Epilepticus - metabolism; Status Epilepticus - pathology; Stroke; Synapses; Synaptic plasticity; Synaptosomes - metabolism; Synaptosomes - pathology; Time Factors; Translation; Translation (Genetics); United States > US; Pennsylvania
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0053464

MicroRNAs regulate protein synthesis by binding non-translated regions of mRNAs and suppressing translation and/or increasing mRNA degradation. MicroRNAs play an important role in the nervous system including controlling synaptic plasticity. Their expression is altered in disease states including stroke, head injury and epilepsy. To better understand microRNA expression changes that might contribute to the development of epilepsy, microRNA arrays were performed on rat hippocampus 4 hours, 48 hours and 3 weeks following an episode of pilocarpine induced status epilepticus. Eighty microRNAs increased at one or more of the time points. No microRNAs decreased at 4 hours, and only a few decreased at 3 weeks, but 188 decreased 48 hours after status epilepticus. The large number of microRNAs with altered expression following status epilepticus suggests that microRNA regulation of translation has the potential to contribute to changes in protein expression during epileptogenesis. We carried out a second set of array's comparing microRNA expression at 48 hours in synaptoneurosome and nuclear fractions of the hippocampus. In control rat hippocampi multiple microRNAs were enriched in the synaptoneurosomal fraction as compared to the nuclear fraction. In contrast, 48 hours after status epilepticus only one microRNA was enriched in the synaptoneurosome fraction. The loss of microRNAs enriched in the synaptoneurosomal fraction implies a dramatic change in translational regulation in synapses 48 hours after status epilepticus.