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The microRNA miR-124 suppresses seizure activity and regulates CREB1 activity.

Wang W, Wang X, Chen L, Zhang Y, Xu Z, Liu J, Jiang G, Li J, Zhang X, Wang K, Wang J, Chen G, Luo J - Expert Rev Mol Med (2016)

Bottom Line: Inhibition of neuronal firing by miR-124 was associated with the suppression of mEPSC, AMPAR- and NMDAR-mediated currents, which were accompanied by decreased surface expression of NMDAR.In addition, miR-124 injection resulted in decreased activity and expression of cAMP-response element-binding protein1 (CREB1). a key regulator in epileptogenesis.Immunoprecipitation studies confirmed that the CREB1 antibody effectively precipitated CREB1 and NMDAR1 but not GLUR1 from rat brain hippocampus.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology,Chongqing Key Laboratory of Neurology,The First Affiliated Hospital of Chongqing Medical University,1 Youyi Road,Chongqing 400016,China.

ABSTRACT
miR-124, a brain-specific microRNA, was originally considered as a key regulator in neuronal differentiation and the development of the nervous system. Here we showed that miR-124 expression was suppressed in patients with epilepsy and rats after drug induced-seizures. Intrahippocampal administration of a miR-124 duplex led to alleviated seizure severity and prolonged onset latency in two rat models (pentylenetetrazole- and pilocarpine-induced seizures), while miR-124 inhibitor led to shortened onset latency in pilocarpine-induced seizure rat models. Moreover, the result of local field potentials (LFPs) records further demonstrated miR-124 may have anti-epilepsy function. Inhibition of neuronal firing by miR-124 was associated with the suppression of mEPSC, AMPAR- and NMDAR-mediated currents, which were accompanied by decreased surface expression of NMDAR. In addition, miR-124 injection resulted in decreased activity and expression of cAMP-response element-binding protein1 (CREB1). a key regulator in epileptogenesis. A dual-luciferase reporter assay was used to confirm that miR-124 targeted directly the 3'UTR of CREB1 gene and repressed the CREB1 expression in HEK293T cells. Immunoprecipitation studies confirmed that the CREB1 antibody effectively precipitated CREB1 and NMDAR1 but not GLUR1 from rat brain hippocampus. These results revealed a previously unknown function of miR-124 in neuronal excitability and provided a new insight into molecular mechanisms underlying epilepsy.

No MeSH data available.


Related in: MedlinePlus

Effect of miR-124 on neuronal hyperexcitability after seizure. (a) Changes of AP frequency. *P < 0.05, compared with control, n = 5 in each group; ◆ P < 0.05, compared with the mimics control, n = 5 in each group. (b) Representative traces of action potential (AP) discharges. (c) Typical trace of LFPs on rats treated with miR-124 mimics and inhibitor. (d) The miR-124 mimics significantly prolonged the latency of epileptiform-like discharges and the miR-124 inhibitor significantly shorted the latency of epileptiform-like discharges compared with the controls in a model of pilocarpine induced seizures, n = 5, ★ P < 0.05, compared with the control. (e) The duration of epileptiform-like discharges last shorter on rats treated with miR-124 mimics and longer on rat treated with miR-124 inhibitor in a model of pilocarpine-induced seizures, n = 5, ★ P < 0.05, compared with the control.
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fig03: Effect of miR-124 on neuronal hyperexcitability after seizure. (a) Changes of AP frequency. *P < 0.05, compared with control, n = 5 in each group; ◆ P < 0.05, compared with the mimics control, n = 5 in each group. (b) Representative traces of action potential (AP) discharges. (c) Typical trace of LFPs on rats treated with miR-124 mimics and inhibitor. (d) The miR-124 mimics significantly prolonged the latency of epileptiform-like discharges and the miR-124 inhibitor significantly shorted the latency of epileptiform-like discharges compared with the controls in a model of pilocarpine induced seizures, n = 5, ★ P < 0.05, compared with the control. (e) The duration of epileptiform-like discharges last shorter on rats treated with miR-124 mimics and longer on rat treated with miR-124 inhibitor in a model of pilocarpine-induced seizures, n = 5, ★ P < 0.05, compared with the control.

Mentions: To test whether the effect of miR-124 on behavioral activity was because of the inhibition of hyperexcitability, we measured action potentials in hippocampal CA1 neurons. As shown in Figure 3, slices from controls (without seizure inducing) exhibited relatively few action potentials. In the brains of rats with seizures induced by pilocarpine, slices with scrambled miRNA mimics control and seizure group showed an outburst of action potentials, whereas slices with 1.0 nm miR-124 mimics exhibited significantly reduced action potential frequencies (Fig. 3a and b; mimics versus control, P < 0.05; mimics versus scrambled mimics, P < 0.05).Figure 3.


The microRNA miR-124 suppresses seizure activity and regulates CREB1 activity.

Wang W, Wang X, Chen L, Zhang Y, Xu Z, Liu J, Jiang G, Li J, Zhang X, Wang K, Wang J, Chen G, Luo J - Expert Rev Mol Med (2016)

Effect of miR-124 on neuronal hyperexcitability after seizure. (a) Changes of AP frequency. *P < 0.05, compared with control, n = 5 in each group; ◆ P < 0.05, compared with the mimics control, n = 5 in each group. (b) Representative traces of action potential (AP) discharges. (c) Typical trace of LFPs on rats treated with miR-124 mimics and inhibitor. (d) The miR-124 mimics significantly prolonged the latency of epileptiform-like discharges and the miR-124 inhibitor significantly shorted the latency of epileptiform-like discharges compared with the controls in a model of pilocarpine induced seizures, n = 5, ★ P < 0.05, compared with the control. (e) The duration of epileptiform-like discharges last shorter on rats treated with miR-124 mimics and longer on rat treated with miR-124 inhibitor in a model of pilocarpine-induced seizures, n = 5, ★ P < 0.05, compared with the control.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4836211&req=5

fig03: Effect of miR-124 on neuronal hyperexcitability after seizure. (a) Changes of AP frequency. *P < 0.05, compared with control, n = 5 in each group; ◆ P < 0.05, compared with the mimics control, n = 5 in each group. (b) Representative traces of action potential (AP) discharges. (c) Typical trace of LFPs on rats treated with miR-124 mimics and inhibitor. (d) The miR-124 mimics significantly prolonged the latency of epileptiform-like discharges and the miR-124 inhibitor significantly shorted the latency of epileptiform-like discharges compared with the controls in a model of pilocarpine induced seizures, n = 5, ★ P < 0.05, compared with the control. (e) The duration of epileptiform-like discharges last shorter on rats treated with miR-124 mimics and longer on rat treated with miR-124 inhibitor in a model of pilocarpine-induced seizures, n = 5, ★ P < 0.05, compared with the control.
Mentions: To test whether the effect of miR-124 on behavioral activity was because of the inhibition of hyperexcitability, we measured action potentials in hippocampal CA1 neurons. As shown in Figure 3, slices from controls (without seizure inducing) exhibited relatively few action potentials. In the brains of rats with seizures induced by pilocarpine, slices with scrambled miRNA mimics control and seizure group showed an outburst of action potentials, whereas slices with 1.0 nm miR-124 mimics exhibited significantly reduced action potential frequencies (Fig. 3a and b; mimics versus control, P < 0.05; mimics versus scrambled mimics, P < 0.05).Figure 3.

Bottom Line: Inhibition of neuronal firing by miR-124 was associated with the suppression of mEPSC, AMPAR- and NMDAR-mediated currents, which were accompanied by decreased surface expression of NMDAR.In addition, miR-124 injection resulted in decreased activity and expression of cAMP-response element-binding protein1 (CREB1). a key regulator in epileptogenesis.Immunoprecipitation studies confirmed that the CREB1 antibody effectively precipitated CREB1 and NMDAR1 but not GLUR1 from rat brain hippocampus.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology,Chongqing Key Laboratory of Neurology,The First Affiliated Hospital of Chongqing Medical University,1 Youyi Road,Chongqing 400016,China.

ABSTRACT
miR-124, a brain-specific microRNA, was originally considered as a key regulator in neuronal differentiation and the development of the nervous system. Here we showed that miR-124 expression was suppressed in patients with epilepsy and rats after drug induced-seizures. Intrahippocampal administration of a miR-124 duplex led to alleviated seizure severity and prolonged onset latency in two rat models (pentylenetetrazole- and pilocarpine-induced seizures), while miR-124 inhibitor led to shortened onset latency in pilocarpine-induced seizure rat models. Moreover, the result of local field potentials (LFPs) records further demonstrated miR-124 may have anti-epilepsy function. Inhibition of neuronal firing by miR-124 was associated with the suppression of mEPSC, AMPAR- and NMDAR-mediated currents, which were accompanied by decreased surface expression of NMDAR. In addition, miR-124 injection resulted in decreased activity and expression of cAMP-response element-binding protein1 (CREB1). a key regulator in epileptogenesis. A dual-luciferase reporter assay was used to confirm that miR-124 targeted directly the 3'UTR of CREB1 gene and repressed the CREB1 expression in HEK293T cells. Immunoprecipitation studies confirmed that the CREB1 antibody effectively precipitated CREB1 and NMDAR1 but not GLUR1 from rat brain hippocampus. These results revealed a previously unknown function of miR-124 in neuronal excitability and provided a new insight into molecular mechanisms underlying epilepsy.

No MeSH data available.


Related in: MedlinePlus