Limits...
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 CREB1 activity in the hippocampus. (a) Sample Western blots of NMDAR1 in normal (without seizure inducing) and model rats (PTZ-induced seizure in rat models) without treatment (control), and in animals treated with mimics control and mimics. (b) Summary of the relative NMDAR1 analysed from h. ▼P > 0.05, compared with the normal, n = 4. (c, d) Immunoprecipitation was used to survey the binding status between CREB1 and NMDAR1 or GLUR1. (e, f) Immunohistochemistry images show strong (e, 24 h after pilocarpine-induced seizures) and weak (f, control group) immunoreactive staining of pCREB in the dentate gyrus. Scale bar, 200 µm. (g) Sample Western blots of pCREB before (normal) and at different time points of pilocarpine-induced seizure. (h) Summary of pCREB activity showing a significant increase after seizures. *P < 0.05, n = 5. (i) Sample Western blots of pCREB in normal (without seizure inducing) and seizure rats without treatment (control), and in rats treated with mimics control and mimics. (j) Summary of the relative pCREB analysed from I. *P < 0.05, compared with the normal. ▲P < 0.05, compared with the mimics control, n = 5. (k) Relative CREB1 mRNA levels in normal (without seizure inducing) and seizure rats without treatment (control) and in animals treated with mimics control and mimics. *P < 0.05, compared with the normal. ▲P < 0.05, compared with the mimics control, n = 5.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4836211&req=5

fig06: Effect of miR-124 on CREB1 activity in the hippocampus. (a) Sample Western blots of NMDAR1 in normal (without seizure inducing) and model rats (PTZ-induced seizure in rat models) without treatment (control), and in animals treated with mimics control and mimics. (b) Summary of the relative NMDAR1 analysed from h. ▼P > 0.05, compared with the normal, n = 4. (c, d) Immunoprecipitation was used to survey the binding status between CREB1 and NMDAR1 or GLUR1. (e, f) Immunohistochemistry images show strong (e, 24 h after pilocarpine-induced seizures) and weak (f, control group) immunoreactive staining of pCREB in the dentate gyrus. Scale bar, 200 µm. (g) Sample Western blots of pCREB before (normal) and at different time points of pilocarpine-induced seizure. (h) Summary of pCREB activity showing a significant increase after seizures. *P < 0.05, n = 5. (i) Sample Western blots of pCREB in normal (without seizure inducing) and seizure rats without treatment (control), and in rats treated with mimics control and mimics. (j) Summary of the relative pCREB analysed from I. *P < 0.05, compared with the normal. ▲P < 0.05, compared with the mimics control, n = 5. (k) Relative CREB1 mRNA levels in normal (without seizure inducing) and seizure rats without treatment (control) and in animals treated with mimics control and mimics. *P < 0.05, compared with the normal. ▲P < 0.05, compared with the mimics control, n = 5.

Mentions: Subsequently, we studied whether preinjection of a miR-124 mimics affected the total expression of NMDAR after PTZ-induced seizures in rat models. After the injection of PTZ, seizure activity led to an increase in NMDAR1 expression in the hippocampus, and the miR-124 mimics partially decreased the expression of NMDAR1; however, none of these changes were significant (P > 0.05, Fig. 6a and b).Figure 6.


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 CREB1 activity in the hippocampus. (a) Sample Western blots of NMDAR1 in normal (without seizure inducing) and model rats (PTZ-induced seizure in rat models) without treatment (control), and in animals treated with mimics control and mimics. (b) Summary of the relative NMDAR1 analysed from h. ▼P > 0.05, compared with the normal, n = 4. (c, d) Immunoprecipitation was used to survey the binding status between CREB1 and NMDAR1 or GLUR1. (e, f) Immunohistochemistry images show strong (e, 24 h after pilocarpine-induced seizures) and weak (f, control group) immunoreactive staining of pCREB in the dentate gyrus. Scale bar, 200 µm. (g) Sample Western blots of pCREB before (normal) and at different time points of pilocarpine-induced seizure. (h) Summary of pCREB activity showing a significant increase after seizures. *P < 0.05, n = 5. (i) Sample Western blots of pCREB in normal (without seizure inducing) and seizure rats without treatment (control), and in rats treated with mimics control and mimics. (j) Summary of the relative pCREB analysed from I. *P < 0.05, compared with the normal. ▲P < 0.05, compared with the mimics control, n = 5. (k) Relative CREB1 mRNA levels in normal (without seizure inducing) and seizure rats without treatment (control) and in animals treated with mimics control and mimics. *P < 0.05, compared with the normal. ▲P < 0.05, compared with the mimics control, n = 5.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig06: Effect of miR-124 on CREB1 activity in the hippocampus. (a) Sample Western blots of NMDAR1 in normal (without seizure inducing) and model rats (PTZ-induced seizure in rat models) without treatment (control), and in animals treated with mimics control and mimics. (b) Summary of the relative NMDAR1 analysed from h. ▼P > 0.05, compared with the normal, n = 4. (c, d) Immunoprecipitation was used to survey the binding status between CREB1 and NMDAR1 or GLUR1. (e, f) Immunohistochemistry images show strong (e, 24 h after pilocarpine-induced seizures) and weak (f, control group) immunoreactive staining of pCREB in the dentate gyrus. Scale bar, 200 µm. (g) Sample Western blots of pCREB before (normal) and at different time points of pilocarpine-induced seizure. (h) Summary of pCREB activity showing a significant increase after seizures. *P < 0.05, n = 5. (i) Sample Western blots of pCREB in normal (without seizure inducing) and seizure rats without treatment (control), and in rats treated with mimics control and mimics. (j) Summary of the relative pCREB analysed from I. *P < 0.05, compared with the normal. ▲P < 0.05, compared with the mimics control, n = 5. (k) Relative CREB1 mRNA levels in normal (without seizure inducing) and seizure rats without treatment (control) and in animals treated with mimics control and mimics. *P < 0.05, compared with the normal. ▲P < 0.05, compared with the mimics control, n = 5.
Mentions: Subsequently, we studied whether preinjection of a miR-124 mimics affected the total expression of NMDAR after PTZ-induced seizures in rat models. After the injection of PTZ, seizure activity led to an increase in NMDAR1 expression in the hippocampus, and the miR-124 mimics partially decreased the expression of NMDAR1; however, none of these changes were significant (P > 0.05, Fig. 6a and b).Figure 6.

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