Downregulation of circular RNA HECTD1 induces neuroprotection against ischemic stroke through the microRNA-133b/TRAF3 pathway.

Abstract

AIMS:

Circular RNAs (circRNAs) have been shown to play crucial roles in various biological processes and human diseases. However, their exact functions in ischemic stroke remain largely unknown. In this study, we explored the functional role of circRNA HECTD1 (circ-HECTD1) and its underlying mechanism in cerebral ischemia/reperfusion injury.

METHODS:

Mouse middle cerebral artery occlusion (MCAO) model and oxygen-glucose deprivation (OGD) model in HT22 cells were used to mimic the cerebral ischemia/reperfusion injury. Brain infarct volume, flow cytometry, caspase 3 activity, NF-κB activity, and TUNEL staining were performed to evaluate the function of circ-HECTD1. Luciferase report assay was used to explore the regulatory mechanism.

FINDINGS:

The results showed that the expression of circ-HECTD1 and tumor necrosis factor receptor-associated factor 3 (TRAF3) was remarkably up-regulated, while miR-133b was down-regulated in oxygen-glucose deprivation (OGD)-induced HT22 cells and mouse middle cerebral artery occlusion (MCAO) model. circ-HECTD1 knockdown relieved OGD-caused neuronal cell death in vitro. Simultaneously, circ-HECTD1 knockdown improved cerebral infarction volume and neuronal apoptosis in MCAO mice. circ-HECTD1 was able to negatively regulate the expression of miR-133b, and TRAF3 is one of the targets of miR-133b. Upregulation of miR-133b inhibited the expression of TRAF3 in OGD-stimulated cells, whereas circ-HECTD1 upregulation reversed this effect. Furthermore, upregulation of miR-133 was able to inhibit OGD-caused cell apoptosis and NF-κB activation, whereas upregulation of circ-HECTD1 attenuated these effects of miR-133b mimics.

SIGNIFICANCE:

Taken together, circ-HECTD1 knockdown inhibited the expression of TRAF3 by targeting miR-133b, thereby attenuating neuronal injury caused by cerebral ischemia.

• Authors: Quande Dai, Yu Ma, Zhonghai Xu, Liang Zhang, Hong Yang, Qin Liu, Jingzhong Wang
• Journal: Life sciences (Life Sci) Vol. 264 Pg. 118626 (Jan 01 2021) ISSN: 1879-0631 [Electronic] Netherlands
• PMID: 33148417 (Publication Type: Journal Article)
• Copyright: Copyright © 2020 Elsevier Inc. All rights reserved.

Chemical References

• Blood Glucose
• MicroRNAs
• Mirn133 microRNA, mouse
• RNA, Circular
• TNF Receptor-Associated Factor 3
• Hectd1 protein, mouse
• Ubiquitin-Protein Ligases
• Casp3 protein, mouse
• Caspase 3
• Oxygen

Topics

• Animals
• Apoptosis
• Blood Glucose (metabolism)
• Brain (pathology)
• Brain Ischemia (pathology)
• Caspase 3 (metabolism)
• Down-Regulation
• Gene Knockdown Techniques
• Ischemic Stroke (genetics)
• Male
• Mice
• Mice, Inbred C57BL
• MicroRNAs (genetics)
• Middle Cerebral Artery (pathology)
• Neurons (pathology)
• Neuroprotection
• Oxygen (metabolism)
• RNA, Circular (genetics)
• Reperfusion Injury (pathology)
• TNF Receptor-Associated Factor 3 (genetics)
• Ubiquitin-Protein Ligases (genetics)