RESUMEN
Excessive environmental exposure to manganese (Mn) has been linked to cognitive impairments, circular RNAs (circRNAs) have been recognized for their roles in epigenetic regulation in various biological processes, including neurological pathogenesis. Previous studies found that ferroptosis, an iron ion-dependent programmed cell death, may be involved in cognitive impairments. However, specific mechanisms underlying the relationship among circRNA, ferroptosis, and neurotoxicity of Mn are not well-understood. In the current study, RNA sequencing was performed to profile RNA expression in Neuro-2a (N2a) cells that were treated with 300 µM Mn. The potential molecular mechanisms of circHmbox1(3,4) in Mn-induced cognitive impairments were investigated via various experiments, such as Western blot and intracerebroventricular injection in mice. We observed a significant decrease in the expression of circHmbox1(3,4) both in vitro and in vivo following Mn treatment. The results of Y maze test and Morris water maze test demonstrated an improvement in learning and memory abilities following circHmbox1(3,4) overexpression in Mn treated mice. Mn treatment may reduce circHmbox1(3,4) biogenesis through lowered expression of E2F1/QKI. Inhibiting circHmbox1(3,4) expression led to GPX4 protein degradation through protein ligation and ubiquitination. Overall, the current study showed that Mn exposure-induced cognitive dysfunction may be mediated through ferroptosis regulated by circHmbox1(3,4).
Asunto(s)
Disfunción Cognitiva , Ferroptosis , Manganeso , ARN Circular , Animales , Ferroptosis/efectos de los fármacos , Manganeso/toxicidad , Disfunción Cognitiva/inducido químicamente , Disfunción Cognitiva/genética , ARN Circular/genética , Masculino , Ratones , Fosfolípido Hidroperóxido Glutatión Peroxidasa/metabolismo , Fosfolípido Hidroperóxido Glutatión Peroxidasa/genética , Ratones Endogámicos C57BL , Línea Celular Tumoral , Aprendizaje por Laberinto/efectos de los fármacosRESUMEN
Overexposure to manganese (Mn) can lead to neurotoxicity, the underlying mechanisms remain incompletely understood. Circular RNAs (circRNAs) have emerged as important regulators in various biological processes. It is plausible that circRNAs may be involved in the biological mechanisms underlying Mn caused neurotoxicity. Here, circRest was downregulated in Mn-exposed mouse neuroblastoma cells (N2a cells) by RNA sequencing and quantitative real-time PCR. When circRest was overexpressed, it led to an increase in cell viability and a decrease in apoptosis following Mn exposure. Conversely, silencing circRest resulted in opposite effects in N2a cells. Further investigation revealed that circRest acts as a mmu-miR-6914-5p sponge, and mmu-miR-6914-5p could bind and inhibit Ephb3, thereby promoting apoptosis in N2a cells. This was confirmed through RNA antisense purification and dual luciferase reporter assays. Additionally, the circRest/mmu-miR-6914-5p/Ephb3 axis may influence memory and learning in mice following Mn exposure. In conclusion, our study uncovers a novel mechanism by which circRest may attenuate Mn caused neurotoxicity via the mmu-miR-6914-5p/Ephb3 axis.