ABSTRACT
BACKGROUND: Neurogenic neuroprotection is a promising approach for treating patients with ischemic brain lesions. Fastigial nucleus stimulation (FNS) has been shown to reduce the tissue damage resulting from focal cerebral ischemia in the earlier studies. However, the mechanisms of neuroprotection induced by FNS remain unclear. MicroRNAs (miRNAs) are a newly discovered group of non-coding small RNA molecules that negatively regulate target gene expression and involved in the regulation of pathological process. To date, there is a lack of knowledge on the expression of miRNA in response to FNS. Thus, we study the regulation of miRNAs in the rat ischemic brain by the neuroprotection effect of FNS. METHODS: In this study, we used an established focal cerebral ischemia/reperfusion (IR) model in rats. MiRNA expression profile of rat ischemic cortex after 1 h of FNS were investigated using deep sequencing. Microarray was performed to study the expression pattern of miRNAs. Functional annotation on the miRNA was carried out by bioinformatics analysis. RESULTS: Two thousand four hundred ninety three miRNAs were detected and found to be miRNAs or miRNA candidates using deep sequencing technology. We found that the FNS-related miRNAs were differentially expressed according microarray data. Bioinformatics analysis indicated that several differentially expressed miRNAs might be a central node of neuroprotection-associated genetic networks and contribute to neuroprotection induced by FNS. CONCLUSIONS: MiRNA acts as a novel regulator and contributes to FNS-induced neuroprotection. Our study provides a better understanding of neuroprotection induced by FNS.
Subject(s)
Cerebellar Nuclei , Computational Biology , Deep Brain Stimulation , High-Throughput Nucleotide Sequencing , MicroRNAs/genetics , Neuroprotection/genetics , Sequence Analysis, RNA , Animals , Brain Ischemia/complications , Male , Molecular Sequence Annotation , Rats , Rats, Sprague-Dawley , Reperfusion Injury/complications , Reperfusion Injury/genetics , Reperfusion Injury/physiopathology , Reperfusion Injury/therapyABSTRACT
Previous studies have shown that fastigial nucleus stimulation (FNS) reduces tissue damage resulting from focal cerebral ischemia. Although the mechanisms of neuroprotection induced by FNS are not entirely understood, important data have been presented in the past two decades. MicroRNAs (miRNAs) are a newly discovered group of non-coding small RNA molecules that negatively regulate target gene expression and are involved in the regulation of cell proliferation and cell apoptosis. To date, no studies have demonstrated whether miRNAs can serve as mediators of the brain's response to FNS, which leads to endogenous neuroprotection. Therefore, this study investigated the profiles of FNS-mediated miRNAs. Using a combination of deep sequencing and microarray with computational analysis, we identified a novel miRNA in the rat ischemic cortex after 1 h of FNS. This novel miRNA (PC-3p-3469_406), herein referred to as rno-miR-676-1, was upregulated in rats with cerebral ischemia after FNS. In vivo observations indicate that this novel miRNA may have antiapoptotic effects and contribute to neuroprotection induced by FNS. Our study provides a better understanding of neuroprotection induced by FNS. MicroRNA (miRNA) is defined as a small non-coding RNA that fulfills both the expression and biogenesis criteria. Here, we describe a novel miRNA in the rat ischemic cortex expressed after 1 h of fastigial nucleus stimulation (FNS). The miRNA was functionally characterized by secondary structure, quantitative expression, the conservation analysis, target gene analysis, and biological functions. We consider rno-miR-676-1 to be a true microRNA and present evidence for its neuroprotective effects exerted after induction by FNS.
Subject(s)
Cerebellar Nuclei/physiology , Electric Stimulation Therapy , Infarction, Middle Cerebral Artery/physiopathology , MicroRNAs/biosynthesis , Animals , High-Throughput Nucleotide Sequencing , In Situ Nick-End Labeling , Male , Oligonucleotide Array Sequence Analysis , Rats , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
AIMS: Studies showed fastigial nucleus stimulation (FNS) reduced brain damage, but the mechanisms of neuroprotection induced by FNS were not entirely understood; MicroRNAs are noncoding RNA molecules that regulate gene expression in a posttranscriptional manner, but their functional consequence in response to ischemia-reperfusion (IR) remains unknown. We investigated the role of microRNA-29c in the neuroprotection induced by FNS in rat. METHODS: The IR rat models were conducted 1 day after FNS. Besides, miR-29c antagomir (or agomir or control) was infused to the left intracerebroventricular 1 day before IR models were conducted. We detected differential expression of Birc2 mRNA (also Bak1mRNA and miR-29c) level among different groups by RT-qPCR. The differential expression of Birc2 protein (also Bak1 protein) level among different groups was surveyed via Western blot. The neuroprotective effects were assessed by infarct volume, neurological deficit, and apoptosis. RESULTS: MiR-29c was decreased after FNS. Moreover, miR-29c directly bound to the predicted 3'-UTR target sites of Birc2 and Bak1 genes. Furthermore, over-expression of miR-29c effectively reduced Birc2 (also Bak1) mRNA and protein levels, increased infarct volume and apoptosis, and deteriorated neurological outcomes, whereas down-regulation played a neuroprotective role. CONCLUSIONS: MiR-29c correlates with the neuroprotection induced by FNS by negatively regulating Birc2 and Bak1.
