MiR224-5p Inhibitor Restrains Neuronal Apoptosis by Targeting NR4A1 in the Oxygen-Glucose Deprivation (OGD) Model

Integration Analysis of miRNA Circulating Expression Following Cerebellar Transcranial Direct Current Stimulation in Patients with Ischemic Stroke

The aim of this study was to explore the molecular mechanisms underlying cerebellar transcranial direct current stimulation (ctDCS) as a rehabilitation intervention for patients with ischemic stroke, focusing on the role of microRNAs (miRNAs). Whole-transcriptome sequencing was employed to obtain circulating expression profiles of miRNAs, long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and mRNAs in patients with ischemic stroke before and after 3-week ctDCS. miRanda software was used to predict the target genes of miRNAs, while Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted to identify biological functions and signaling pathways. Subsequently, competing endogenous RNA (ceRNA) regulatory networks comprising circRNA-miRNA-mRNA and lncRNA-miRNA-mRNA interactions were constructed. Key miRNAs in blood samples were validated through quantitative RT-PCR. In total, 43 miRNAs, 807 lncRNAs, 1,111 circRNAs, and 201 mRNAs were differentially expressed after ctDCS compared with before ctDCS. Bioinformatics analyses revealed significant enrichment of target genes regulated by differentially expressed miRNAs across multiple biological pathways. CeRNA regulatory networks implied that several miRNAs were closely related to the ctDCS. Among them, hsa-miR-181a-5p, hsa-miR-224-5p, and hsa-miR-340-3p showed significantly downregulated expression levels as confirmed by qRT-PCR. This study conducted the first-ever assessment of miRNA expression patterns in patients with ischemic stroke undergoing ctDCS. The findings revealed that ctDCS induces alterations in miRNA levels, suggesting their potential utility as therapeutic markers.

[MiR-224-5p overexpression inhibits oxidative stress by regulating the PI3K/Akt/FoxO1 axis to attenuate hypoxia/reoxygenation-induced cardiomyocyte injury]

OBJECTIVES

To investigate the regulatory role of miRNA-224-5p in hypoxia/reoxygenation (H/R) -induced H9c2 cardiomyocyte injury.

METHODS

Plasma samples were collected from 160 patients with acute myocardial infarction and 80 healthy controls(HC) to measure miRNA-224-5p levels and other biochemical parameters. In cultured H9c2 cells with H/R injury, the effects of transfection with miR-224-5p mimics or a negative control sequence on cell viability, malondialdehyde (MDA) content, and superoxide dismutase 2 (SOD2) and lactate dehydrogenase (LDH) activities were tested. Dual luciferase reporter gene assay was performed to verify the targeting relationship between miR-224-5p and PTEN. Bioinformatics methods were used to analyze the potential mechanisms of the target genes. The expression of miRNA-224-5p in the treated cells was detected with qRT-PCR, the protein expressions of PTEN, Bcl-2, Bax, cleaved caspase-3, SOD2, p-PI3K/PI3K, p-Akt/Ak and p-FoxO1/FoxO1 were determined using Western blotting, and cell apoptosis was analysed with flow cytometry.

RESULTS

The levels of blood glucose, C-reactive protein, CK, CK-MB and cTnI were significantly higher in the AMI group compared with the HC group (P < 0.05). The expression level of miR-224-5p was significantly lowered in patients with STEMI and NSTEMI and in H9c2 cells with H/R injury. The viability of H9c2 cells decreased time-dependently following H/R injury. PTEN was a target gene of miR-224-5p, and the PI3K/Akt pathway was the most significantly enriched pathway. H9c2 cells with H/R injury showed significantly decreased SOD2 activity, increased LDH activity and MDA content, increased cell apoptosis, decreased protein expression levels of p-PI3K, p-Akt, p-FoxO1, SOD2, and Bcl-2, and increased expressions of PTEN, Bax, and cleaved caspase-3. These changes were obviously attenuated by trasnfection of the cells with miR-224-5p mimics prior to H/R exposure.

CONCLUSION

MiR-224-5p overexpression upregulates the expression of the antioxidant gene SOD2 through the PI3K/Akt/FoxO1 axis to relieve H/R-induced oxidative stress and reduce apoptosis of H9c2 cells.

Role of autophagy and transcriptome regulation in acute brain injury

Autophagy is an evolutionarily conserved intracellular system that routes distinct cytoplasmic cargo to lysosomes for degradation and recycling. Accumulating evidence highlight the mechanisms of autophagy, such as clearance of proteins, carbohydrates, lipids and damaged organelles. The critical role of autophagy in selective degradation of the transcriptome is still emerging and could shape the total proteome of the cell, and thus can regulate the homeostasis under stressful conditions. Unregulated autophagy that potentiates secondary brain damage is a key pathological features of acute CNS injuries such as stroke and traumatic brain injury. This review discussed the mutual modulation of autophagy and RNA and its significance in mediating the functional consequences of acute CNS injuries.

Interleukin-35 exhibits protective effects in a rat model of hypoxic-ischemic encephalopathy through the inhibition of microglia-mediated inflammation

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) brain damage is related to inflammatory responses and oxidative stress. Interleukin (IL)-35 is an antioxidant and anti-inflammatory cytokine. Thus, the effect of IL-35 treatment on neonatal rats with hypoxic-ischemic brain injury was investigated.

METHODS

A total of 96 7-day-old Sprague Dawley rats were randomly divided into three groups: sham group, HIE group, and IL-35 group. After left common carotid occlusion and 2.5 h hypoxia (HI injury), IL-35 (20 µg/g) was intraperitoneally (i.p.) administered to the pups. In vitro, BV2 cells were treated with or without IL-35 6 h before oxygen-glucose deprivation (OGD) insult and the microglia culture medium (MCM) was co-cultured with b.End3 cerebral vascular endothelial cells. Microglial polarization and activation were assessed by real-time quantitative polymerase chain reaction (RT-qPCR), Western blot, and enzyme-linked immunosorbent assay (ELISA). Endothelial cell dysfunction was measured by cell counting kit-8 and Western blot assays.

RESULTS

Administration of IL-35 alleviated neurological deficiencies, decreased brain edema, ameliorated cerebral infarction, and limited M1 microglial polarization in HI-injured pups. Meanwhile, IL-35 decreased pro-inflammatory cytokines, tumor necrosis factor-α, IL-1β, and reactive oxygen species generation in OGD-induced bEnd.3 cells. Furthermore, IL-35 treatment could reverse the vascular endothelial cell injury induced by microglial polarization. Finally, IL-35 markedly suppressed the activation of hypoxia-inducible factor-1α (HIF-1α) and the nuclear factor-κB (NF-κB) signaling pathway in vivo and in vitro.

CONCLUSIONS

IL-35 relieved hypoxic-ischemic-induced brain injury and inhibited the inflammatory response by suppressing microglial polarization and activation. These results suggest that IL-35 might have potential applications for the treatment of HIE.

The Circ-CYP24A1-miR-224-PRLR Axis Impairs Cell Proliferation and Apoptosis in Recurrent Miscarriage

Aim

Recurrent miscarriage (RM) is associated with numerous clinical factors. However, some RM occurred without specific factors. It has been revealed that some molecules such as hormones, miRNAs, and transcription factors are involved in RM by regulating proliferation, apoptosis, etc. However, the mechanism of RM has yet to be identified clearly. Circular RNAs (circRNAs) are a class of endogenous non-coding RNAs that often act as sponges for miRNAs or binds to proteins involved in biological processes. However, the functional role of circRNAs in the uterine decidua of patients with early RM is still unclear. In this study, we aimed to investigate the mechanisms of circ-CYP24A1 in RM.

Methods

The Dual-Luciferase Activity Assay was designed to analyze the bonding between circ-CYP24A1 and miR-224, and miR-224 and prolactin receptor (PRLR) mRNA 3′UTR. In situ hybridization (ISH) and immunohistochemistry (IHC) were used to observe the expression of circ-CYP24A1 and PRLR in the decidua. Rescue experiments were performed to investigate the regulating effects of circ-CYP24A1, miR-224, and PRLR. Western blotting was conducted to test the expression level of PRLR. The proliferation and apoptosis-related markers in Ishikawa cells were analyzed using CCK8, immunofluorescence staining, and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay.

Results

In this study, based on the microarray analysis data, we identified a high level of circ-CYP24A1 and PRLR in the decidua of patients with early RM. Based on the bioinformatics prediction, the binding relationship between circ-CYP24A1 and miR-224, as well as miR-224 and PRLR, were verified. Functional experiments demonstrated that circ-CYP24A1 regulated proliferation and apoptosis by binding to and inhibiting miR-224, resulting in increased PRLR expression. Taken together, this study provides new insights into the mechanism of RM.

Conclusion

In this study, we found that circ-CYP24A1 plays a role in RM by impairing the balance of cell proliferation and apoptosis by sponging miR-224, thereby regulating PRLR.