Antagomirs Targeting MicroRNA-134 Increase Limk1 Levels After Experimental Seizures in Vitro and in Vivo

Abstract

Background: MiR-134 is enriched in dendrites of hippocampal neurons and plays crucial roles in the progress of epilepsy. The present study aims to investigate the effects of antagomirs targeting miroRNA-134 (Ant-134) on limk1 expression and the binding of miR-134 and limk1 in experimental seizure. Methods: Status epilepticus (SE) rat model was established by lithium chloride-pilocarpine injection and was treated with Ant-134 by intracerebroventricular injection. Low Mg²⁺-exposed primary neurons were used as an in vitro model of SE. The expression of miR-134 was determined using real-time PCR. Protein expressions of limk1 and cofilin were determined by Western blotting. Luciferase reporter assay was used to examine the binding between miR-134 and limk1 3’-untranslated region. Results: The expression of miR-134 was markedly enhanced in hippocampus of the SE rats and low Mg²⁺-exposed neurons. Ant-134 increased the expression of limk1 and reduced the expression of cofilin in the SE hippocampus and Low Mg²⁺-exposed neurons. In addition, luciferase reporter assay confirmed that miR-134 bound limk1 3’-UTR. MiR-134 overexpression inhibited limk1 mRNA and protein expressions in neurons. Conclusion: Blockage of miR-134 upregulates limk1 expression and downregulated cofilin expression in hippocampus of the SE rats. This mechanism may contribute to the neuroprotective effects of Ant-134.

Spared CA1 pyramidal neuron function and hippocampal performance following antisense knockdown of microRNA‐134

“…Although the mechanism of action is not fully understood, ant-134 has been reported to reduce density and increase volume of dendritic spines in hippocampal pyramidal cells, 6,7 likely mediated by an increase in LimK1, a target of microRNA-134. 9,10 This suggests that ant-134 could reduce seizures through a disease-modifying effect. Prior to clinical translation, it is critical to determine whether ant-134 has potential adverse effects on normal neuronal functions that could preclude its use in clinic.…”

“…The latter is particularly relevant because it demonstrates that ant‐134 may also affect seizure threshold in nonepileptic tissue. Although the mechanism of action is not fully understood, ant‐134 has been reported to reduce density and increase volume of dendritic spines in hippocampal pyramidal cells, likely mediated by an increase in LimK1, a target of microRNA‐134 . This suggests that ant‐134 could reduce seizures through a disease‐modifying effect.…”

MicroRNA alterations in neuropathologic cognitive disorders with an emphasis on dementia: Lessons from animal models

“…Furthermore, the Golgi staining data indicated that the elevation of miR-21 simultaneously reduced branch points and somata size of the neurons in the hippocampus of the injured brain (Hu et al, 2015). Also, agomir of miR-21-5p ameliorated MWM outcomes, whereas antagomir re- (Sun, Gao et al, 2017). and miR-18b-5p decreased (Sørensen, Nygaard, Nielsen, Jensen, & Christensen, 2014).…”

“…Furthermore, miR-26 downregulated TNF-α/NF-κB signaling and consequently suppresses inflammation. This evidence indicated that miR-26b and miR-207 might affect the process of IHinduced cognitive dysfunction, but it requires further studies (Sun, Gao et al, 2017). Mohammadipoor-Ghasemabad, Sangtarash, Sheibani, et al (2019) demonstrated that the declined level of pri-miR-1b, miR-1b, and BDNF mRNA in the hippocampus of SD ovariectomized (OVX) female rat upregulated via treadmill training.…”

“…The next miRNA, miRNA‐144, seems like a critical miRNA in aging, neurodegenerative, and cognitive disorders. While miR‐144‐3p antagomir‐treated injured rats spend more time in goal quadrant of MWM, miR‐144‐3p negatively affects cognitive status following TBI probably due to the accumulation of β‐amyloid and ADAM10 suppression, respectively (Sun, Gao et al, 2017).…”