Article

Expression Patterns of miR-124, miR-134, miR-132, and miR-21 in an Immature Rat Model and Children with Mesial Temporal Lobe Epilepsy

Department of Pediatrics, Xiangya Hospital of Central South University, No. 87 Xiangya Road, Changsha, Hunan, 410008, China.
Journal of Molecular Neuroscience (Impact Factor: 2.34). 01/2013; 50(2). DOI: 10.1007/s12031-013-9953-3
Source: PubMed

ABSTRACT

Mesial temporal lobe epilepsy (MTLE) is a particularly devastating form of human epilepsy with significant incidence of medical intractability. MicroRNAs (miRs) are small, noncoding RNAs that regulate the posttranscriptional expression of protein-coding mRNAs, which may have key roles in the pathogenesis of MTLE development. To study the dynamic expression patterns of brain-specific miR-124 and miR-134 and inflammation-related miR-132 and miR-21, we performed qPCR on the hippocampi of immature rats at 25 days of age. Expressions were monitored in the three stages of MTEL and in the control hippocampal tissues corresponding to the same timeframes. A similar expression method was applied to hippocampi obtained from children with MTLE and normal controls. The expression patterns of miR-124 and miR-134 nearly showed the same dynamics in the three stages of MTLE development. On the other hand, miR-132 and miR-21 showed significant upregulation in acute and chronic stages, while in the latent stage, miR-132 was upregulated and miR-21 was downregulated. The four miRs were upregulated in hippocampal tissues obtained from children with MTLE. The significant upregulation of miR-124 and miR-134 in the seizure-related stages and children suggested that both can be potential targets for anticonvulsant drugs in the epileptic developing brains, while the different expression patterns of miR-132 and miR-21 may suggest different functions in MTLE pathogenesis.

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    • "Human temporal lobe epilepsy and experimentally induced epilepsy result in changes of the level of specific miRNAs in brain tissue in a region-and even neural compartment-dependent manner78798081. If one considers different induction protocols, experimental designs and animal species used, then a core set of four epilepsyrelated miRNAs has emerged (miR-132, miR-134, miR-124, miR-34a)82838485. Pilocarpine-induced epilepsy results in increase of hippocampal pri-miR-132[60]and miR-132 level[60,85]. "
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    ABSTRACT: MicroRNAs (miRNAs) are rapidly emerging as central regulators of gene expression in the postnatal mammalian brain. Initial studies mostly focused on the function of specific miRNAs during the development of neuronal connectivity in culture, using classical gain- and loss-of-function approaches. More recently, first examples have documented important roles of miRNAs in plastic processes in intact neural circuits in the rodent brain related to higher cognitive abilities and neuropsychiatric disease. At the same time, evidence is accumulating that miRNA function itself is subjected to sophisticated control mechanisms engaged by the activity of neural circuits. In this review, we attempt to pay tribute to this mutual relationship between miRNAs and synaptic plasticity. In particular, in the first part, we summarize how neuronal activity influences each step in the lifetime of miRNAs, including the regulation of transcription, maturation, gene regulatory function and turnover in mammals. In the second part, we discuss recent examples of miRNA function in synaptic plasticity in rodent models and their implications for higher cognitive function and neurological disorders, with a special emphasis on epilepsy as a disorder of abnormal nerve cell activity.
    Full-text · Article · Sep 2014 · Philosophical Transactions of The Royal Society B Biological Sciences
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    • "miRNAs are also involved in the regulation of several aspects of the innate, adaptive immune responses and inflammationrelated disorders. Studies uncovered a subset of miRNAs which are brain-enriched including miRNAs (124, 134, 9, and 138) and inflammationrelated miRNAs including (132, 181a, 221, and 222) which were extensively studied in multiple brain disease in both developing and adult brains [4] [10] [11] [12], and also in infectious diseases [13] [14] [15]. "
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    • "Indeed, miRNA responses to seizures often display sharp temporal changes (Sano et al. 2012). Given the independent findings of miR-134 upregulation in the hippocampus of children and adults with TLE (Jimenez- Mateos et al. 2012; Peng et al. 2013), these findings establish increased miR-134 as a conserved molecular response to seizures in the brain. Fig. 6 Reduced clinical seizures and mortality in Ant-134 mice subject to SE. a, b Graphs showing average Racine scores for Scr (n = 11) and Ant-134 (n = 12) animals, a during 90 min after PILO injection and b recorded after lorazepam termination of SE (**P \ 0.01; *P \ 0.05, compared to Scr). "
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