Retracted: Sevoflurane improves nerve regeneration and repair of neurological deficit in brain damage rats via microRNA-490-5p/CDK1 axis

Gut microbiota and transcriptome dynamics in every-other-day fasting are associated with neuroprotection in rats with spinal cord injury

Introduction

Every-other-day fasting (EODF) is a classical intermittent fasting (IF) mode with neuroprotective effects that promotes motor function recovery after spinal cord injury (SCI) in rats. However, its dynamic effects on the gut microbiota and spinal cord transcriptome remain unknown.

Methods

In this study, 16S rRNA sequencing and RNA-seq analysis were used to investigate the effects of ad libitum (AL) and EODF dietary modes on the structural characteristics of rat gut microbiota in rats and the spinal cord transcriptome at various time points after SCI induction.

Results

Our results showed that both dietary modes affected the bacterial community composition in SCI rats, with EODF treatment inducing and suppressing dynamic changes in the abundances of potentially anti-inflammatory and pro-inflammatory bacteria. Furthermore, the differentially expressed genes (DEGs) enriched after EODF intervention in SCI rats were associated with various biological events, including immune inflammatory response, cell differentiation, protein modification, neural growth, and apoptosis. In particular, significant spatiotemporal differences were apparent in the DEGs associated with neuroprotection between the EODF and AL interventions. These DGEs were mainly focused on days 1, 3, and 7 after SCI. The relative abundance of certain genera was significantly correlated with DEGs associated with neuroprotective effects in the EODF-SCI group.

Discussion

Our results showed that EODF treatment may exert neuroprotective effects by modulating the transcriptome expression profile following SCI in rats. Furthermore, gut microbiota may be partially involved in mediating these effects.

Decoding competitive endogenous RNA regulatory network in postoperative cognitive dysfunction

Postoperative cognitive dysfunction (POCD) is a common postoperative neurological complication in elderly patients. Circular RNAs (circRNAs) are abundant in the mammalian brain and can probably regulate cognitive function. However, the competitive endogenous RNA (ceRNA) regulatory network in POCD remains illiterate. Transcriptomic signatures in the hippocampus of POCD mice derived from the Gene Expression Omnibus (GEO) dataset GSE190880, GSE95070, and GSE115440 were used to identify the circRNA, miRNA, and mRNA expression profiles of POCD mice compared with controls, respectively. A set of differentially expressed RNAs, including 119 circRNAs, 33 miRNAs, and 49 mRNAs were identified. Transcript validation showed the enhanced expression of circ_0001634, circ_0001345, and circ_0001493. A ceRNA regulatory network composed of three circRNAs, three miRNAs, and six mRNAs was established. The hub mRNAs in the ceRNA network were further found to be involved in the hormone catabolic process and regulation of canonical Wnt signaling pathway, revealing their crucial role in POCD. Finally, three miRNAs and four mRNAs were verified by qRT-PCR. These results based on bioinformatics and PCR array suggest that circ_0001634/miR-490-5p/Rbm47, circ_0001634/miR-490-5p/Sostdc1, circ_0001634/miR-7001-5p/Sostdc1, circ_0001345/miR-7001-5p/Sostdc1, and circ_0001493/miR-7001-5p/Sostdc1 may be novel diagnostic biomarkers and therapeutic targets for POCD.

Biological Effect of Quercetin in Repairing Brain Damage and Cerebral Changes in Rats: Molecular Docking and In Vivo Studies

This study examined the protective effect of quercetin against high-altitude-induced brain damage in rats. A molecular docking study was performed to investigate the potential effect of quercetin in reducing brain damages through its ability to target the oxidative stress enzymes. Biomarker assessment screening assays were also performed then followed by in vivo studies. Three groups of rats were divided into the control group, an untreated animal model group with induced brain damage, and finally, the quercetin treated group that received quercetin dose equal to 20 mg/kg of their body weights. Molecular docking studies and biomarker assessment screening assays proved the potential effect of quercetin to affect the level of representative biomarkers glutathione (GSH), glutathione reductase (GR), glutathione-S-transferase (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA). Additionally, the protective effect of quercetin against high altitude, low pressure, and low oxygen was also investigated by exploring the brain histopathology of experimental rats. Brain damage was observed in the untreated animal model group. After treatment with quercetin, the cerebral edema in the brain tissues was improved significantly, confirming the protective effects of quercetin. Therefore, quercetin can be used as a natural food additive to protect from the highaltitude-induced brain damage.

The mechanism of sevoflurane post-treatment alleviating hypoxic-ischemic encephalopathy by affecting histone methyltransferase G9a in rats

Hypoxic-ischemic encephalopathy (HIE) is recognized as the main cause of neonatal death, and efficient treatment strategies remain limited. This study aims to investigate the mechanism of sevoflurane (SF) post-treatment in alleviating HIE in rats. The HIE rat model and oxygen-glucose deprivation (OGD) cell model were established, and adeno-associated virus (AAV)-histone-lysine N-methyltransferase EHMT2 (G9a) was transfected after SF treatment. The learning and memory ability and the levels of nerve growth factor (NGF)/brain-derived neurotrophic factor (BDNF) were evaluated and determined. The levels of G9a/histone H3 lysine 9 dimethylation (H3K9me2) and the enrichment level of H3K9me2 in the promoter region of BDNF gene were analyzed. After SF post-treatment, the neurons in cerebral cortex, the learning and memory skills and the contents of NGF/BDNF were increased, while the apoptosis and G9a/H3K9me2 levels were reduced. After overexpression of G9a in vitro/vivo, the enrichment levels of H3K9me2 in the promoter region of BDNF were increased, the levels of BDNF were decreased, the neurons were damaged and the learning and memory abilities of HIE rats were impaired. The conclusion is that SF post-treatment can promote the expression of BDNF by inhibiting H3K9me2 on the BDNF gene promoter and inhibiting G9a, thus alleviating HIE in rats.

MicroRNA-490-3p and -490-5p in carcinogenesis: Separate or the same goal?

MicroRNA (miR)-490-3p and miR-490-5p, located on chromosome 7q33, are two independent mature products of miR-490 exerting distinct effects on tumor progression. miR-490-3p and miR-490-5p possess antitumor properties. miR-490-3p dysfunction has been associated with malignancies including colorectal cancer, while the abnormal function of miR-490-5p has been more considerably associated with bladder cancer (for example). At present, there are 30 and 11 target genes of miR-490-3p and miR-490-5p, respectively, that have been experimentally verified, of which the cyclin D1 (CCND1) gene is a common target. Through these target genes, miR-490-3p and miR-490-5p are involved in 7 and 3 signaling pathways, respectively, of which only 2 are shared regulatory signaling pathways. The present review introduces two competing endogenous RNA (ceRNA) regulatory networks centered on miR-490-3p and miR-490-5p. These networks may be important promoters of tumor cell proliferation, invasiveness, metastatic potential and apoptosis. Unlike miR-490-5p, miR-490-3p plays a unique role in promoting cancer. However, both are promising molecular markers for early cancer diagnosis and prognosis. In addition, miR-490-3p was also found to be associated with the chemical resistance of cisplatin and paclitaxel. The present review focuses on the abnormal expression of miR-490-3p and miR-490-5p in different tumor types, and their complex ceRNA regulatory networks. The clinical value of miR-490-3p and miR-490-5p in cancer diagnosis, prognosis and treatment is also clarified, and an explanation for the opposing effects of miR-490-3p in tumor research is provided.