MiR-340-5p alleviates oxygen-glucose deprivation/reoxygenation-induced neuronal injury via PI3K/Akt activation by targeting PDCD4

αAsarone alleviates neuronal injury by facilitating autophagy via miR-499-5p/PDCD4/ATG5 signaling pathway in ischemia stroke

Introduction

αAsarone, an essential oil derived from Acorus gramineus Aiton, which has been successfully used to treat epilepsy in traditional chinese medicine, and has also been reported to confer neuroprotective effects on stroke. However, its mechanism of action remains poorly understood.

Methods

The effects of αAsarone on autophagy were examined by WB, RT-qPCR, immunofluorescence colocalization, transmission electron microscope, and autophagic flux activity was measured by infecting HT22 cells with mRFP-GFP-LC3 adenovirus. And then, cells were transfected with both mimic-miR-499-5p and inhibit-miR-499-5p to investigate the role of miR-499-5p in regulating the effects of αAsarone on stroke. To further clarify the protective effect of αAsarone in vivo, TTC staining, neurological function score, H&E staining, Nissl staining, Laser speckle contrast imaging, transmission electron microscopy, immunofluorescence colocalization, WB and RT-qPCR were performed in the MCAO mice.

Results

αAsarone was observed to inhibit the apoptosis of neuronal cells, and enhance autophagy. In addition, αAsarone promoted the expression of miR-499-5p. Targeting miR-499-5p can negatively regulate PDCD4 expression and the results from the dual-luciferase reporter assay demonstrate the direct targeting of PDCD4 by miR-499-5p. Promoting miR-499-5p can decrease the expression of PDCD4, increase ATG5, and enhance the protective effect of αAsarone on OGD/R injury while inhibiting miR-499-5p can weaken the effect of αAsarone. In vivo experiments further confirmed that αAsarone improved mice MCAO as evidenced by the amelioration of the neurological deficits and facilitated neuronal autophagy. Furthermore, we found that αAsarone reversed the effect of chloroquine, an autophagy inhibitor, and enhanced neuronal autophagy via miR-499-5p/PDCD4/ATG5 signaling pathway.

Discussion

Our data suggest that αAsarone alleviates neuronal injury of stroke by facilitating neuronal autophagy through the miR-499-5p/PDCD4/ATG5 signaling pathway.

The expression and significance of long noncoding RNA XIST/microRNA-340-5p axis and metabolic reprogramming biomarkers in acute cerebrovascular stroke patients: A cross-sectional study

Stroke represents a worldwide major cause of death and long-term adult disability. Various human diseases pathogenesis, including stroke, are associated with dysregulation of long noncoding RNA (LncRNA) and microRNA (miR). However, their potential role is yet to be elucidated. This work aimed to assess the role of LncRNA X-inactive specific transcript (XIST), miR-340-5p, and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase (PFKFB)3 as peripheral blood biomarkers for acute cerebrovascular stroke diagnosis and severity prediction. This cross-sectional study included 120 participants divided into 3 groups; healthy controls, acute ischemic stroke patients, and acute hemorrhagic stroke patients. XIST, miR-340-5p, and PFKFB3 expression were assessed by RT-qPCR, whereas PFKFB3, hypoxia inducible factor 1-alpha (HIF-1α) and vascular endothelial growth factor (VEGF) serum proteins were measured by ELISA. Compared to healthy control, XIST and PFKFB3 mRNA expression were significantly upregulated in stroke patients, with the highest levels in hemorrhagic type, while miR-340-5p expression was significantly downregulated and its lowest level was in hemorrhagic stroke. Serum PFKFB3, HIF-1α, and VEGF levels were significantly elevated in stroke patients with the highest levels in hemorrhagic stroke. These biomarkers correlated with National Institute of Health Stroke Scale (NIHSS). Regression analysis using NIHSS as dependent variable confirmed that PFKFB3 mRNA relative expression was the independent predictor (β = 0.7, P = .003). Receiver operating characteristic analyses revealed that XIST, miR-340-5p, and PFKFB3 mRNA relative expression levels were useful biomarkers discriminating ischemic from hemorrhagic stroke (AUC were 0.99, 0.979, and 0.980, respectively). XIST, miR-340-5p, and PFKFB3 might be involved in acute cerebrovascular stroke pathogenesis and progression providing opportunities for early detection and assessing the severity.

Urine miR-340-5p Predicts the Adverse Prognosis of Sepsis-Associated Acute Kidney Injury and Regulates Renal Tubular Epithelial Cell Injury by Targeting KDM4C

INTRODUCTION

Sepsis-associated acute kidney injury (SA-AKI) is a common complication of sepsis. miR-340-5p has been identified as an effective biomarker of various human diseases. As the downstream target, the involvement of lysine (K)-specific demethylase 4C (KDM4C) in SA-AKI would help interpret the regulatory mechanism of miR-340-5p. The significance of miR-340-5p in the onset and progression of SA-AKI was evaluated to provide a potential therapeutic target for SA-AKI.

METHODS

This study enrolled 64 healthy individuals (control) and 159 sepsis patients (92 SA-AKI and 67 non-AKI) and collected urine samples. The urine level of miR-340-5p was analyzed by PCR, and a series of statistical analyses were conducted to assess the clinical significance of miR-340-5p in the occurrence and development of SA-AKI. The injured renal tubular epithelial cells were established with LPS induction. The roles of miR-340-5p in cellular processes were evaluated.

RESULTS

Increasing urine miR-340-5p discriminated SA-AKI patients from healthy individuals (AUC = 0.934) and non-AKI sepsis patients (AUC = 0.806) sensitively. Additionally, elevated miR-340-5p could predict the adverse prognosis (HR = 5.128, 95% CI = 1.259-20.892) and malignant development of SA-AKI patients. In vitro, lipopolysaccharide (LPS) also induced an increased level of miR-340-5p and significant cell injury in the renal tubular epithelial cell; silencing miR-340-5p could alleviate the suppressed proliferation, migration, and invasion caused by LPS. In mechanism, miR-340-5p negatively regulated KDM4C, which mediated the function of miR-340-5p.

CONCLUSION

miR-340-5p served as a diagnostic and prognostic biomarker of SA-AKI and regulated renal tubular epithelial cell injury via modulating KDM4C.

Analysis of genes differentially expressed in the cortex of mice with the Tbl1xr1Y446C/Y446C variant

Transducin β-like 1 X-linked receptor 1 (mouse Tbl1xr1) or TBL1X/Y related 1 (human TBL1XR1), part of the NCoR/SMRT corepressor complex, is involved in nuclear receptor signaling. Variants in TBL1XR1 cause a variety of neurodevelopmental disorders including Pierpont syndrome caused by the p.Tyr446Cys variant. We recently reported a mouse model carrying the Tbl1xr1Y446C/Y446C variant as a model for Pierpont syndrome. To obtain insight into mechanisms involved in altered brain development we studied gene expression patterns in the cortex of mutant and wild type (WT) mice, using RNA-sequencing, differentially expressed gene (DEG) analysis, gene set enrichment analysis (GSEA), weighted gene correlation network analysis (WGCNA) and hub gene analysis. We validated results in mutated mouse cortex, as well as in BV2 and SK-N-AS cell lines, in both of which Tbl1xr1 was knocked down by siRNA. Two DEGs (adj.P. Val < 0.05) were found in the cortex, Mpeg1 (downregulated in mutant mice) and 2900052N01Rik (upregulated in mutant mice). GSEA, WGCNA and hub gene analysis demonstrated changes in genes involved in ion channel function and neuroinflammation in the cortex of the Tbl1xr1Y446C/Y446C mice. The lowered expression of ion channel genes Kcnh3 and Kcnj4 mRNA was validated in the mutant mouse cortex, and increased expression of TRIM9, associated with neuroinflammation, was confirmed in the SK-N-AS cell line. Conclusively, our results show altered expression of genes involved in ion channel function and neuroinflammation in the cortex of the Tbl1xr1Y446C/Y446C mice. These may partly explain the impaired neurodevelopment observed in individuals with Pierpont syndrome and related TBL1XR1-related disorders.

Analysis of Differential microRNA Expression in the Hippocampus of Scopolamine-Induced Amnesic Mouse Model

Amnesia is characterized by memory deficits linked to various neurodegenerative pathologies and can be induced by the administration of scopolamine, a cholinergic antagonist. Scopolamine-induced amnesia is a well-studied pharmacological animal model that simulates memory impairment caused by aging, brain illnesses, neuropathologies, and trauma. However, the molecular mechanism of amnesia, more importantly in terms of microRNA (miRNA) regulation, is not well understood. Therefore, this study aimed to analyze miRNA profiles in the hippocampus of both control mice and those treated with scopolamine (amnesic mice). Initially, a short cDNA library was prepared for each sample and then sequenced on the Illumina platform. Among the total differentially expressed miRNAs, 113 were significantly upregulated and 96 were downregulated in the scopolamine group in comparison to the control group. Ten upregulated and ten downregulated miRNAs were validated to confirm the reliability of the sequencing results using qRT-PCR (quantitative real-time PCR). Furthermore, we performed a target prediction analysis intersecting the results from TargetScan, miRDB (miRNA database), and Miranda to analyze the targets of the dysregulated miRNAs. We also conducted a pathway analysis to investigate the molecular, cellular, and biological functions of these targets. miRNA‒target interactions were found to play roles in various signaling pathways during amnesia. These results provide an initial insight for the contribution of miRNAs to scopolamine-induced amnesia, as well as their possible application as markers of disease pathology.

Targeting PI3K/Akt in Cerebral Ischemia Reperfusion Injury Alleviation: From Signaling Networks to Targeted Therapy

Ischemia/reperfusion (I/R) injury is a pathological event that results in reperfusion due to low blood flow to an organ. Cerebral ischemia is a common cerebrovascular disease with high mortality, and reperfusion is the current standard intervention. However, reperfusion may further induce cellular damage and dysfunction known as cerebral ischemia/reperfusion injury (CIRI). Currently, strategies for the clinical management of CIRI are limited, necessitating the exploration of novel and efficacious treatment modalities for the benefit of patients. PI3K/Akt signaling pathway is an important cellular process associated with the disease. Stimulation of the PI3K/Akt pathway enhances I/R injury in multiple organs such as heart, brain, lung, and liver. It stands as a pivotal signaling pathway crucial for diminishing cerebral infarction size and safeguarding the functionality of brain tissue after CIRI. During CIRI, activation of the PI3K/Akt pathway exhibits a protective effect on CIRI. Furthermore, activation of the PI3K/Akt pathway has the potential to augment the activity of antioxidant enzymes, resulting in a decrease in reactive oxygen species (ROS) and the associated oxidative stress. Meanwhile, PI3K/Akt plays a neuroprotective role by inhibiting inflammatory responses and apoptosis. For example, PI3K/Akt interacts with NF-κB, Nrf2, and MAPK signaling pathways to mitigate CIRI. This article is aimed to explore the pivotal role and underlying mechanism of PI3K/Akt in ameliorating CIRI and investigate the influence of ischemic preconditioning and post-processing, as well as the impact of pertinent drugs or activators targeting the PI3K/Akt pathway on CIRI. The primary objective is to furnish compelling evidence supporting the activation of PI3K/Akt in the context of CIRI, elucidating its mechanistic intricacies. By doing so, the paper aims to underscore the critical contribution of PI3K/Akt in mitigating CIRI, providing a theoretical foundation for considering the PI3K/Akt pathway as a viable target for CIRI treatment.

Knockdown of IGF2BP3 Down-Regulates PDCD4 Levels to Attenuate Hypoxic-Ischemic Brain Damage

BACKGROUND

Hypoxic-ischemic brain damage (HIBD) is a prevalent brain injury with high mortality and morbidity. It results from hypoxia and ischemia of the brain due to various perinatal factors. A previous study showed that knockdown of programmed cell death factor 4 (PDCD4) could reduce infarction injury resulting from ischemia/reperfusion injury. However, exact mechanism by which PDCD4 acts in HIBD is not yet understood. Our aim in present investigation was to investigate the function and mechanism of PDCD4 in alleviating HIBD.

METHODS

An HIBD model was developed using neonatal rats. After 48 h of modeling, short-term neurological function was evaluated and the brain tissue removed for assessment of cerebral infarct volume and brain water content (BWC). A cell model of oxygen glucose deprivation/reoxygenation (OGD/R) was also constructed. Overexpression or knockdown of insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3) or PDCD4 was performed in pretreated cells.

RESULTS

The geotaxis reflex time, cerebral infarct volume, and BWC all increased after HIBD in this neonatal rat model. Additionally, the levels of PDCD4 and of the N6-Methyladenosine (m6A) reader protein IGF2BP3 were increased in HIBD rats and OGD/R-stimulated pheochromocytoma (PC12) cells relative to controls. Moreover, OGD/R-stimulated pheochromocytoma PC12 cells showed decreased cell viability, increased apoptosis, and elevated Interleukin 6 (IL-6), Interleukin 1 β (IL-1β), and tumor necrosis factor-α (TNF-α) contents. These features were reversed after knocking down IGF2BP3. The interaction between IGF2BP3 protein and PDCD4 mRNA was confirmed by RNA immunoprecipitation and RNA pull-down assays. Furthermore, knockdown of IGF2BP3 in OGD/R-stimulated PC12 cells reduced cell damage via down-regulation of PDCD4. Finally, the IGF2BP3/PDCD4 axis alleviated OGD/R-induced cell injury in primary cortical neurons (PCNs).

CONCLUSIONS

PDCD4 and m6A reader protein IGF2BP3 were up-regulated in an HIBD neonatal rat model. Knockdown of IGF2BP3 in OGD/R-stimulated PC12 cells or PCNs alleviated cell damage through reducing PDCD4.

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.

Circular RNAs: Promising Treatment Targets and Biomarkers of Ischemic Stroke

Ischemic stroke is one of the most significant causes of morbidity and mortality worldwide. However, there is a dearth of effective drugs and treatment methods for ischemic stroke. Significant numbers of circular RNAs (circRNAs) exhibit abnormal expression following ischemic stroke and are considered potential therapeutic targets. CircRNAs have emerged as promising biomarkers due to their stable expression in peripheral blood and their potential significance in ischemic stroke diagnosis and prognosis. This review provides a summary of 31 circRNAs involved in the pathophysiological processes of apoptosis, autophagy, inflammation, oxidative stress, and angiogenesis following ischemic stroke. Furthermore, we discuss the mechanisms of action of said circRNAs and their potential clinical applications. Ultimately, circRNAs exhibit promise as both therapeutic targets and biomarkers for ischemic stroke.

GTF2E2 downregulated by miR-340-5p inhibits the malignant progression of glioblastoma

Glioblastoma is the most common malignant tumor in the central nervous system. The general transcription factor IIE subunit beta (GTF2E2) is crucial for physiological and pathological functions, but its roles in the malignant biological function of glioma remain ambiguous. CCK-8, colony formation assays, TUNEL assays, cell migration assays, wound-healing assays, and xenograft model were established to investigate the biological functions of GTF2E2 both in vitro and in vivo. GTF2E2 was overexpressed in glioma and was associated with poor prognosis of glioma patients. Biological functions of GTF2E2 were investigated both in vitro and in vi0vo by multiple experiments. Moreover, we explored the possible mechanisms of GTF2E2. In our results, we demonstrated that GTF2E2 could be regulated by miR-340-5p directly or indirectly. CCND1 was transcriptionally affected by GTF2E2 and glioma progression was then regulated. Our data presented the overexpression of GTF2E2 in glioma and indicated the association between GTF2E2 and glioma prognosis. GTF2E2 was found to be regulated by miR-340-5p and thus affect downstream gene expressions and glioma progression. Our results indicate that GTF2E2 might be a potential target in the diagnosis and treatments of glioblastoma.

MiR-93-5p inhibits retinal neurons apoptosis by regulating PDCD4 in acute ocular hypertension model

The present study focused on the effect of miR-93-5p on apoptosis of retinal neurons in acute ocular hypertension (AOH) model by regulating PDCD4 and explored its related mechanism. We detected that miR-93-5p expression was decreased and PDCD4 expression was increased in the AOH retina by qRT-PCR. Therefore, we explored the role of miR-93-5p and PDCD4. MiR-93-5p overexpression inhibited the apoptosis of retinal neurons and the expression of PDCD4 in vivo and in vitro. Inhibiting the expression of PDCD4 via transfected interfering RNA decreased the apoptosis of retinal cells and increased the expression of PI3K/Akt pathway-related proteins in vitro. However, the addition of PI3K protein inhibitor LY294002 reversed this effect, leading to a decrease of PI3K/Akt pathway protein expression and an increase of apoptosis-related protein Bax/Bcl-2 expression ratio. Finally, up-regulating miR-93-5p or down-regulating PDCD4 increased the expression of PI3K/Akt pathway protein in vivo. In conclusion, under the condition of AOH injury, miR-93-5p-inhibiting PDCD4 expression reduced the apoptosis of retinal neurons by activating PI3K/Akt pathway.

Ursolic acid ameliorates traumatic brain injury in mice by regulating microRNA-141-mediated PDCD4/PI3K/AKT signaling pathway

BACKGROUND

Neuronal apoptosis and inflammation are the key pathogenic features of secondary brain injury, which results in the neurological impairment that traumatic brain injury (TBI) patients experience. Ursolic Acid (UA) has been shown to have neuroprotective properties against brain damage, however, detailed mechanisms have not been fully disclosed. Research on brain-related microRNAs (miRNAs) has opened up new possibilities for the neuroprotective treatment of UA by manipulating miRNAs. The present study was designed to investigate the impact of UA on neuronal apoptosis and the inflammatory response in TBI mice.

METHODS

The mice's neurologic condition was assessed using the modified neurological severity score (mNSS) and the learning and memory abilities were assessed using the Morris water maze (MWM). Cell apoptosis, oxidative stress, and inflammation were utilized to examine the impact of UA on neuronal pathological damage. miR-141-3p was selected to evaluate whether UA influences miRNAs in a way that has neuroprotective benefits.

RESULTS

The results showed that UA markedly decreased brain edema and neuronal mortality through oxidative stress and neuroinflammation in TBI mice. Using data from the GEO database, we found that miR-141-3p was considerably downregulated in TBI mice and that this downregulation was reversed by UA treatment. Further studies have shown that UA regulates miR-141-3p expression to exhibit its neuroprotective effect in mouse models and cell injury models. Then, miR-141-3p was discovered to directly target PDCD4 in TBI mice and neurons, a well-known PI3K/AKT pathway regulator in the neurons. Most importantly, the upregulation of phosphorylated (p)-AKT and p-PI3K provided the most compelling evidence that UA reactivated the PI3K/AKT pathway in the TBI mouse model, which was through regulating miR-141-3p.

CONCLUSION

Our findings support the notion that UA can improve TBI by modulating miR-141 mediated PDCD4/PI3K/AKT signaling pathway.

Knockdown of PDCD4 ameliorates neural cell apoptosis and mitochondrial injury through activating the PI3K/AKT/mTOR signal in Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a complex neurodegenerative disorder and hampers normal living. It has been reported that programmed cell death 4 (PDCD4) is associated with tumor suppression, inflammatory response, and apoptosis.

OBJECTIVE

The aim of this study was to investigate the role of PDCD4 in PD.

METHODS

The in vivo and in vitro PD models were established by MPTP-induced mice and MMP+ stimulated MN9D cells, respectively. The expression of PDCD4 was detected by western blot. The MN9D cell viability and apoptosis were determined by MTT and flow cytometry assay. Moreover, the MN9D cell mitochondrial injury was evaluated by JC-1 staining.

RESULTS

In this study, PDCD4 was highly expressed in brain tissue of MPTP-induced PD mouse model. In a loss-function experiments, knockdown of PDCD4 promoted MN9D cell viability and allayed MPP+-triggered MN9D cell apoptosis. Furthermore, knockdown of PDCD4 ameliorated MPP+-evoked MN9D cell mitochondrial injury. Mechanically, knockdown of PDCD4 abolished the effect of MMP+ stimulation via activating phosphoinositide 3-kinase(PI3K)/AKT/mammalian target of rapamycin (mTOR) signal. Notably, the protective effects of shPDCD4 on cell apoptosis and mitochondrial injury were suppressed by PI3K inhibitor LY294002.

CONCLUSION

In summary,knockdown of PDCD4 ameliorates neural cell apoptosis and mitochondrial injury through activating the PI3K/AKT/mTOR signal, providing a novel target for PD treatment.

AVAILABILITY OF DATA AND MATERIALS

All data generated or analyzed during this study are included in this published article.

CircRBM33 induces endothelial dysfunction by targeting the miR-6838-5p/PDCD4 axis affecting blood-brain barrier in mice with cerebral ischemia-reperfusion injury

BACKGROUND

circRNAs (circRNAs) are involved in the process of cerebral ischemia-reperfusion injury (CI/RI). Our study aims to explore circRBM33 in the endothelial function of the blood-brain barrier (BBB).

METHODS

The mouse middle cerebral artery occlusion model (MCAO) was established and restored to perfusion, and OGD/R-induced endothelial cells were used to simulate CI/RI. circRBM33, miR-6838-5p and PDCD4, as well as Occludin, ZO-1 and Claudin-5 TJs were evaluated by quantitative PCR and Western blot. The ring structure of circRBM33 was verified by RNAse R and actinomycin D experiments. MTT and LDH Cytotoxicity assay determined viability and toxicity, and flow cytometry determined apoptosis rate. Inflammatory cytokines and the number of microglia in brain tissue were measured by ELISA and IHC. The interaction between genes was verified by RIP and dual luciferase reporter assay.

RESULTS

circRBM33 was a circrRNA present in the cytoplasm and up-regulated in the brain tissue of MCAO mice and OGD/R-induced endothelial cells. Silenced circRBM33 promoted Occludin, ZO-1, and Claudin-5 expression and cell proliferation, and inhibited cytotoxicity, inflammatory response, and apoptosis. Functionally, circRBM33-absorbed miR-6838-5p was involved in regulating PDCD4, leading to endothelial cell dysfunction, and thus affecting the function of the BBB.

CONCLUSIONS

circRBM33 by mediating miR-6838-5p/PDCD4 axis induces endothelial dysfunction, thereby affecting the BBB in mice with CI/RI.

Astrocyte-derived exosomal nicotinamide phosphoribosyltransferase (Nampt) ameliorates ischemic stroke injury by targeting AMPK/mTOR signaling to induce autophagy

Acute ischemic stroke (AIS) is a global cerebrovascular disease with high disability and mortality, which has no effective therapy. Studies have demonstrated that astrocyte-derived exosomes (ADEXs) provided neuroprotection in experimental stroke models. Nevertheless, the role of exosomes derived from oxygen-glucose-deprivation/reoxygenation-stimulated astrocytes (OGD/R-stimulated astrocytes; OGD/R-ADEXs) in AIS remains largely unknown. Here, we found that OGD/R-ADEXs significantly reduced OGD/R-induced neuronal death and promoted neuronal autophagy. These effects were reversed when astrocytes were pretreated with GW4869, an exosome secretion inhibitor, or when hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs) was knocked down. Neuroprotection was also observed during treatment with OGD/R-ADEXs in vivo. Further studies showed that Nampt, played a vital effect in the regulation of autophagy, was significantly increased in OGD/R-ADEXs. Knockdown of Nampt in astrocytes abolished the above-mentioned effects of OGD/R-ADEXs. Mechanistically, Nampt increased autophagy and decreased cell death by modulating AMPK/mTOR signaling, which recognized as a key signaling pathway of autophagy after AIS. Collectively, these results showed that Nampt released by OGD/R-ADEXs ameliorated acute ischemic stroke during neuronal injury by targeting AMPK/mTOR signaling to induce autophagy. Our study revealed a new key factor in the secretion of exosomes by OGD/R astrocytes, which regulated autophagy and induced neuroprotection in a mouse stroke model.

CircSEMA4B inhibits the progression of breast cancer by encoding a novel protein SEMA4B-211aa and regulating AKT phosphorylation

PI3K/AKT signaling pathway plays an important role in regulating the tumorigenesis, recurrence, and metastasis of breast cancer (BC). In this study, we discovered a circRNA with protein-coding potential, which we named circSEMA4B. CircSEMA4B could encode a novel protein, SEMA4B-211aa. Both circSEMA4B and SEMA4B-211aa were remarkably downregulated in BC tissues and cell lines. Low expression of circSEMA4B was positively associated with TNM stage, tumor size, lymph node metastasis, and distant metastasis of BC patients. The functional investigation showed that circSEMA4B and SEMA4B-211aa could significantly inhibit the proliferation and migration of BC in vivo and in vitro. Of note, SEMA4B-211aa inhibited the generation of PIP3 by binding to p85, thereby inhibiting the phosphorylation of AKT (Thr308). CircSEMA4B inhibited the phosphorylation of AKT (Ser473) through miR-330-3p/PDCD4 axis. Taken together, circSEMA4B is a novel negative regulator of PI3K/AKT signaling pathway, providing novel mechanistic insights into the underlying mechanisms of BC.

SPP1/AnxA1/TIMP1 as Essential Genes Regulate the Inflammatory Response in the Acute Phase of Cerebral Ischemia-Reperfusion in Rats

Background

Ischemic injury in stroke is followed by extensive neurovascular inflammation and changes in ischemic penumbra gene expression patterns. However, the key molecules involved in the inflammatory response during the acute phase of ischemic stroke remain unclear.

Methods

Gene expression profiles of two rat ischemic stroke-related data sets, GSE61616 and GSE97537, were downloaded from the GEO database for Gene Set Enrichment Analysis (GSEA). Then, GEO2R was used to screen differentially expressed genes (DEGs). Furthermore, 170 differentially expressed intersection genes were screened and analyzed for Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. Candidate genes and miRNAs were obtained by DAVID, Metascape, Cytoscape, STRING, and TargetScan. Finally, the rat middle cerebral artery occlusion-reperfusion (MCAO/R) model was constructed, and qRT-PCR was used to verify the predicted potential miRNA molecule and its target genes.

Results

GO and KEGG analyses showed that 170 genes were highly associated with inflammatory cell activation and cytokine production. After cluster analysis, seven hub genes highly correlated with post-stroke neuroinflammation were obtained: Cxcl1, Kng1, Il6, AnxA1, TIMP1, SPP1, and Ccl6. The results of TargetScan further suggested that miR-340-5p may negatively regulate SPP1, AnxA1, and TIMP1 simultaneously. In the ischemic penumbra of rats 24 h after MCAO/R, the level of miR-340-5p significantly decreased compared with the control group, while the concentration of SPP1, AnxA1, and TIMP1 increased. Time-course studies demonstrated that the mRNA expression levels of SPP1, AnxA1, and TIMP1 fluctuated dramatically throughout the acute phase of cerebral ischemia-reperfusion (I/R).

Conclusion

Our study suggests that differentially expressed genes SPP1, TIMP1, and ANXA1 may play a vital role in the inflammatory response during the acute phase of cerebral ischemia-reperfusion injury. These genes may be negatively regulated by miR-340-5p. Our results may provide new insights into the complex pathophysiological mechanisms of secondary inflammation after stroke.

MiR-340-5p alleviates neuroinflammation and neuronal injury via suppressing STING in subarachnoid hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) is a severe acute neurological disorder. SAH causes neuroinflammation and leads to early brain injury (EBI) and secondary injury. MicroRNAs are crucial regulators in a variety of neurological diseases. This study was performed to decipher how miR-340-5p functions in SAH.

METHODS

An experimental mouse model with SAH was established by the intravascular perforation, and the in vitro SAH model was constructed by exposing cocultured primary neurons and microglia to oxyhemoglobin. After overexpression of miR-340-5p in mice, the neurobehavioral disorders were evaluated by Garcia test; brain edema was evaluated by wet-dry method; blood-brain barrier (BBB) damage was detected with Evan's blue staining; levels of inflammatory cytokines were detected with enzyme-linked immunosorbent assay. After miR-340-5p was transfected in to microglia, Iba-1 expression was detected by Western blot, and neuronal apoptosis were detected with flow cytometry. The targeting relationship between miR-340-5p and STING was verified by dual-luciferase reporter gene assay and RNA immunoprecipitation assay.

RESULTS

MiR-340-5p was significantly inhibited in the brain tissues of mice with SAH and microglia of SAH model, and neurological impairment, brain edema, BBB injury, and neuroinflammation were significantly alleviated in mice after overexpressing miR-340-5p. STING was identified as a target of miR-340-5p, and STING overexpression could counteract the effects of miR-340-5p overexpression on neurons.

CONCLUSION

MiR-340-5p can attenuate EBI caused by SAH-induced neuroinflammation by inhibiting STING.

MiR-21 participates in the neuroprotection of diazoxide against hypoxic-ischemia encephalopathy by targeting PDCD4

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) is one of the leading causes of neonatal death and permanent neurological disability. Here, we designed to quest therapeutic effects of diazoxide (DZ) on HIE and its mechanism.

METHODS

The cell model of HIE was established. CCK8 and flow cytometry were applied to test cell viability and apoptosis. RT-qPCR and western blotting was evaluated to the expression of miR-21, PDCD4, PI3K, and p-AKT/AKT. Commercial kits were employed to detect SOD, MDA, LDH. DCFH-DA was used to measure intracellular ROS. ELISA was performed to estimate IL-1β, IL-6 and TNF-α. Dual-luciferase reporter gene and RIP assay were applied to confirm the binding relationships between miR-21 and PDCD4.

RESULTS

In H19-7 cells and PC12 cells stimulated by OGD, with low cell viability, high apoptosis, miR-21 high expression and PDCD4 low expression. However, the functions were all reversed by DZ administration. Furthermore, miR-21 inhibitor could abolish the beneficial effects of DZ on OGD-induced cells. Besides, miR-21 could interact with PDCD4. In addition, PDCD4 involved with the regulation of DZ to OGD-induced cells via PI3K/AKT pathway.

CONCLUSION

DZ enhanced miR-21 level and inhibited PDCD4 level via PI3K/AKT pathway to resisted HIE.

Exploring biomarkers for ischemic stroke through integrated microarray data analysis

Stroke is the third leading cause of disability-adjusted life years worldwide, and drugs available for its treatment are limited. This study aimed to explore high-confidence candidate genes associated with ischemic stroke (IS) through bioinformatics analysis and identify potential diagnostic biomarkers and gene-drug interactions. Weighted gene coexpression network analysis (WGCNA) and differentially expressed genes (DEGs) were integrated to identify overlapping genes. Then, high-confidence candidate genes were screened by least absolute shrinkage and selection operator (LASSO) regression. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic value of high-confidence candidate genes as biomarkers for IS. The NetworkAnalyst database was used to construct the TF-gene network and miRNA-TF regulatory network of the high-confidence candidate genes. The DGIdb database was used to identified gene-drug interactions. Through the comprehensive analysis of GSE58294 and GSE16561, 10 high-confidence candidate genes were identified by LASSO regression: ARG1, LY96, ABCA1, SLC22A4, CD163, TPM2, SLC25A42, ID3, FAM102A and CD79B. FAM102A had the highest diagnostic value, and the area under curve (AUC), sensitivity and specificity values were 0.974, 0.919 and 0.936, respectively. The HPA database demonstrated that 10 high-confidence candidate genes were expressed in the brain and blood in normal humans. Finally, DGIdb database analysis identified 8 gene-drug interactions. We identified IS-related diagnostic biomarkers and gene-drug interactions that potentially provide new insights into the diagnosis and treatment of IS.

Circular RNA PUM1 performs as a competing endogenous RNA of microRNA-340-5p to mediate DEAD-box helicase 5 to mitigate cerebral ischemia-reperfusion injury

Cerebral ischemia-reperfusion damages local brain tissue and impairs brain function, but its specific pathogenesis is still uncertain. Recent studies have clarified circPUM1 is aberrantly elevated in cerebral ischemia-reperfusion injury; however, circPUM1ʹs function in cerebral ischemia-reperfusion-induced neuronal injury remains ambiguous. The results illustrated circPUM1 and DEAD-box helicase 5 were decreased, but microRNA-340-5p was elevated in transient middle cerebral artery occlusion mice and oxygen glucose deprivation/reoxygenation-treated SH-SY5Y cells. Knockdown of circPUM1 aggravated the neuronal injury in transient middle cerebral artery occlusion mice and motivated glial cell activation, neuronal apoptosis and inflammation. Enhancing circPUM1 restrained oxygen glucose deprivation/reoxygenation-induced SH-SY5Y cell apoptosis, the release of lactate dehydrogenase and inflammatory factors, and activation of nuclear factor-kappaB pathway, while elevating microRNA-340-5p aggravated oxygen glucose deprivation/reoxygenation-induced cell damage. Functional rescue experiments exhibited that the impacts of knockdown or enhancement of circPUM1 were turned around by microRNA-340-5p downregulation and DEAD-box helicase 5 silencing, respectively. Moreover, it was demonstrated that circPUM1 competitively adsorbed microRNA-340-5p to mediate DEAD-box helicase 5. All in all, this study clarifies that circPUM1 mitigates cerebral ischemia-reperfusion-induced neuronal injury by targeting the microRNA-340-5p/DEAD-box helicase 5 axis.

Knockdown of circ_0007290 alleviates oxygen-glucose deprivation-induced neuronal injury by regulating miR-496/PDCD4 axis

Circular RNAs (circRNAs) are highly enriched in the brain and involved in many types of central nervous system pathologies. Herein, this study aimed to investigate the role and mechanism of circ_0007290 in ischemic stroke. The oxygen-glucose deprivation (OGD) model was established with the HCN-2 cells in vitro. Levels of genes and proteins was detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. In vitro experiments were conducted using cell counting kit-8 (CCK-8) assay, EdU (5-ethynyl-2'-deoxyuridine) assay, flow cytometry and ELISA, respectively. The levels of lactate dehydrogenase (LDH) were measured using the commercial kit. RNA pull-down and dual-luciferase reporter assay were used to identify the target relationship between miR-496 and circ_0007290 or PDCD4 (programmed cell death protein 4). Circ_0007290 expression was elevated in acute ischemic stroke (AIS) patients and OGD-induced cell injury model. OGD stimulation induced neuronal apoptosis, promoted LDH release, and enhanced inflammation in HCN-2 cells, which all were reversed by the knockdown of circ_0007290. Mechanistically, circ_0007290 served as a sponge for miR-496 to relieve the repression of miR-496 on the expression of its target PDCD4. Moreover, miR-496 inhibition or PDCD4 overexpression abolished the inhibitory effects of circ_0007290 knockdown OGD-evoked neuronal injury. Knockdown of circ_0007290 alleviated OGD-induced neuronal injury by regulating miR-496/PDCD4 axis, providing a novel insight into the pathology of ischemic stroke.

Interleukin-35 from Interleukin-4-Stimulated Macrophages Alleviates Oxygen Glucose Deprivation/Re-oxygenation-Induced Neuronal Cell Death via the Wnt/β-Catenin Signaling Pathway

Currently, brain stroke is one of the leading causes of death and disabilities. It results in depletion of oxygen and glucose in certain areas of the brain, leading to neuronal death. Re-oxygenation has been proven to attenuate neuronal damage; however, sudden oxygen supply may also cause oxidative stress and subsequent inflammation. Hence, therapies to suppress re-oxygenation-induced oxidative damage are urgently needed. Interleukin (IL)-35, an immunomodulator secreted by regulatory T cells and regulatory B cells, is proven to be a strong immune-repressive cytokine. Here, we investigated the potential role of IL-35 in a disease model of oxygen glucose deprivation/re-oxygenation (OGD/R) and found that M2 macrophage-derived IL-35 significantly alleviated inflammatory response induced by oxidative stress. Our results also showed that IL-35 treatment decreased OGD/R-induced neuronal cell death and inflammatory response. Additionally, we demonstrated that IL-35 suppresses inflammatory response via the Wnt/β-catenin signaling pathway. Hence, our findings indicate that IL-35 therapy has great potential in the treatment of OGD/R-induced oxidative damage and related inflammatory diseases.

Influence of age and sex on microRNA response and recovery in the hippocampus following sepsis

Sepsis, defined as a dysregulated host immune response to infection, is a common and dangerous clinical syndrome. The excessive host inflammatory response can induce immediate and persistent cognitive decline, which can be worse in older individuals. Sex-specific differences in the outcome of infectious diseases and sepsis appear to favor females. We employed a murine model to examine the influence of age and sex on the brain's microRNA (miR) response following sepsis. Young and old mice of both sexes underwent cecal ligation and puncture (CLP) with daily restraint stress. Expression of hippocampal miR was examined in age- and sex-matched controls at 1 and 4 days post-CLP. Few miR were modified in a similar manner across age or sex and these few miR were generally associated with neuroprotection against inflammation. Similar to previous work examining transcription, young females exhibited a better recovery of the miR profile from day 1 to day 4, relative to young males and old females. For young males and all female groups, the initial response mainly involved a decrease in miR expression. In contrast, old males exhibited only upregulated miR on day 1 and day 4 and many of the miR upregulated on day 1 and day 4 were linked to neurodegeneration, increased neuroinflammation, and cognitive impairment. The results emphasize age and sex differences in epigenetic mechanisms that likely contribute to susceptibility or resilience to cognitive impairment due to sepsis.

Serum Exosomal mir-340-5p Promotes Angiogenesis in Brain Microvascular Endothelial Cells During Oxygen-Glucose Deprivation

Ischemic stroke (IS) is a cerebrovascular disease with high morbidity, recurrence, and mortality. The purpose of the present study was to investigate the role and mechanism of human serum exosomes on angiogenesis after IS. The middle cerebral artery occlusion (MCAO) in vivo model and oxygen-glucose deprivation (OGD) in vitro model were established. Human serum exosomes from healthy samples (NC-exo) and IS samples (IS-exo) were injected into MCAO mice. Neurobehavioral tests were performed to assess the extent of neurological deficits. The infarct volume was assessed by 2,3,5-triphenyl tetrazolium chloride (TTC) staining, and the levels of inflammatory cytokines were analyzed by enzyme-linked immunosorbent assay (ELISA). In addition, human serum exosomes were cocultured with brain microvascular endothelial cells (BMECs). Cell Counting Kit-8 (CCK-8), Transwell, and tubule formation assays were performed to investigate the proliferation, migration, invasion, length, and branching of BMECs. The miRNA expression profiles of NC-exo and IS-exo were analyzed by high-throughput sequencing and compared. Bioinformatics and luciferase reporter assays were performed to evaluate the relationship between miR-340-5p and CD147. Serum NC-exo and IS-exo had protective effects on IS injury and promoted BMEC angiogenesis. Interestingly, the protective effect of IS-exo was weaker than that of NC-exo. In addition, miR-340-5p was downregulated in IS-exo, and miR-340-5p accelerated angiogenesis of BMECs after OGD. Mechanistically, CD147 was confirmed as a direct target of miR-340-5p. Finally, miR-340-5p promoted angiogenesis by directly targeting CD147. Serum exosome-derived miR-340-5p promote angiogenesis in OGD-induced BMECs by targeting CD147.

Knockdown of XIST up-regulates 263294miR-340-5p to relieve myocardial ischaemia-reperfusion injury via inhibiting cyclin D1

Aim

Long non‐coding RNAs (lncRNAs) are known to participate in various human diseases, while the role of X inactive‐specific transcript (XIST) binding microRNA‐340‐5p (miR‐340‐5p) remains seldom studied. We aim to identify the role of the XIST/miR‐340‐5p/cyclin D1 (CCND1) axis in the myocardial ischaemia–reperfusion injury (MIRI).

Methods and results

The mouse MIRI models were established. The expression of XIST, miR‐340‐5p, and CCND1 in mouse myocardial tissues in MIRI mice was assessed. The MIRI mice were respectively treated with altered XIST, miR‐340‐5p, or CCND1. The changes of myocardial enzyme activity were assessed, and the cardiac function was evaluated. Myocardial pathological changes, cardiomyocyte apoptosis and related apoptotic factors, oxidative stress and inflammatory factors were observed in myocardial tissues in mice with MIRI. The binding relationships between XIST and miR‐340‐5p, and between miR‐340‐5p and CCND1 were confirmed. XIST and CCND1 were up‐regulated while miR‐340‐5p was down‐regulated in MIRI mice. Silenced XIST could elevated miR‐340‐5p expression and reduced CCND1 expression, so as to promoted cardiac function and suppressed myocardial enzyme activity, ameliorated pathological changes, decelerated cardiomyocyte apoptosis by elevating Bcl‐2 but reducing the levels of Bax and Caspase‐3, attenuated inflammatory response by repressing IL‐6 and TNF‐α levels, and mitigated oxidative stress by reducing MDA contents and increasing CAT, GSH‐Px, and SOD levels in MIRI mice. XIST sponged miR‐340‐5p and miR‐340‐5p targeted CCND1.

Conclusions

Knockdown of XIST up‐regulates miR‐340‐5p to relieve MIRI via inhibiting CCND1.

LncRNA CEBPA-AS1 alleviates cerebral ischemia-reperfusion injury by sponging miR-340-5p regulating APPL1/LKB1/AMPK pathway

Long non-coding RNAs (lncRNAs) regulate neurological damage in cerebral ischemia-reperfusion injury (CIRI). This study aimed to investigate the biological roles of lncRNA CEBPA-AS1 in CIRI. Middle cerebral artery occlusion and ischemia-reperfusion injury (MCAO/IR) rat model and oxygen-glucose deprivation and reoxygenation (OGD/R) cell lines were generated; the expression of CEBPA-AS1 was evaluated by qRT-PCR. The effects of CEBPA-AS1 on cell apoptosis and nerve damage were examined. The downstream microRNA (miRNA) and mRNA of CEBPA-AS1 were predicted and verified. We found that overexpression of CEBPA-AS1 could attenuate MCAO/IR-induced nerve damage and neuronal apoptosis in the rat model. Knockdown of CEBPA-AS1 aggravated cell apoptosis and enhanced the production of LDH and MDA in the OGD/R cells. Upon examining the molecular mechanisms, we found that CEBPA-AS1 stimulated APPL1 expression by combining with miR-340-5p, thereby regulating the APPL1/LKB1/AMPK pathway. In the rescue experiments, CEBPA-AS1 overexpression was found to attenuate OGD/R-induced cell apoptosis and MCAO/IR induced nerve damage, while miR-340-5p reversed these effects of CEBPA-AS1. In conclusion, CEBPA-AS1 could decrease CIRI by sponging miR-340-5, regulating the APPL1/LKB1/AMPK pathway.

miR-340-5p inhibits pancreatic acinar cell inflammation and apoptosis via targeted inhibition of HMGB1

Acute pancreatitis (AP) is a common gastrointestinal disease that affects 1 million individuals worldwide. Inflammation and apoptosis are considered to be important pathogenic mechanisms of AP, and high mobility group box 1 (HMGB1) has been shown to play a particularly important role in the etiology of this disease. MicroRNAs (miRs) are emerging as critical regulators of gene expression and, as such, they represent a promising area of therapeutic target identification and development for a variety of diseases, including AP. Using the online database query (microRNA.org), the current study identified a site in the 3' untranslated region of HMGB1 mRNA that was a viable target for miR-340-5p. The present study aimed to investigate the association between miR-340-5p and HMGB1 expression in pancreatic acinar cells following lipopolysaccharide (LPS) treatment by performing luciferase, western blotting and reverse transcription-quantitative PCR assays. The results suggest that miR-340-5p attenuates the induction of HMGB1 by LPS, thereby inhibiting inflammation and apoptosis via blunted activation of Toll-like receptor 4 and enhanced AKT signaling. Thus, the therapeutic application of miR-340-5p may be a useful strategy in AP via upregulation of HMGB1 and subsequent promotion of inflammation and apoptosis.

MicroRNA-32-5p attenuates cerebral ischemia/reperfusion injuries by modulating the phosphatase and tensin homologous protein

Non-coding RNAs have recently attracted much attention with the potential in the treatment of cerebral ischemia/reperfusion (I/R) injuries. In this study, we investigated the role of miR-32-5p in cerebral I/R injuries by using oxygen-glucose deprivation/reperfusion (OGD/R) PC12 cells and middle cerebral artery occlusion/reperfusion (MCAO/R) rats. The expression of genes and proteins were detected by RT-qPCR and Western blot, respectively. The function of OGD/R PC12 cells was detected using MTT assay and flow cytometry analysis. The influences of MCAO/R on rats was evaluated by measuring the infarct volume and brain water content. Bioinformatics analysis and luciferase gene reporter assay were used to identify the relationship between miR-32-5p and PTEN. The results showed that miR-32-5p had neuroprotective effects on OGD/R induced PC12 cells and MCAO/R injured rats' brain. The level of miR-32-5p was significantly reduced after OGD/R. Overexpression of miR-32-5p significantly reduced MCAO/R-induced brain damages in rats. Moreover, PTEN was found to be a target of miR-32-5p, and overexpression of PTEN attenuated the effects of miR-32-5p overexpression on cerebral I/R injuries. In addition, miR-32-5p was able to activate PI3K/AKT signaling by inhibiting PTEN. In conclusion, miR-32-5p prevents brain I/R injuries through modulating PTEN/PI3K/AKT signaling pathway.

Extracellular vesicles derived from bone marrow mesenchymal stem cells alleviate neuroinflammation after diabetic intracerebral hemorrhage via the miR-183-5p/PDCD4/NLRP3 pathway

OBJECTIVES

Intracerebral hemorrhage (ICH) induced by diabetes results in further brain injury and nerve cell death. Bone marrow mesenchymal stem cell (BMSC) transplantation contributes to attenuating neurological deficits after ICH. This study investigated the mechanism of extracellular vesicles (EVs) derived from BMSCs in reducing neuroinflammation after diabetic ICH.

METHODS

BMSC-EVs were isolated and identified. The rat model of db/db-ICH was established and the model rats were administered with EVs. miR-183-5p expression in brain tissues of db/db-ICH rats was detected. The brain injury of db/db-ICH rats was evaluated by measuring neurobehavioral score, brain water content and inflammatory factors. BV2 cells were cultured in vitro to establish high-glucose (HG)-Hemin-BV2 cell model. The levels of reactive oxygen species (ROS) and inflammatory factors in BV2 cells were measured, and BV2 cell viability and apoptosis were assessed. The targeting relationship between miR-183-5p and PDCD4 was predicted and verified. The activation of PDCD4/NLRP3 pathway in rat brain tissues and BV2 cells was detected.

RESULTS

miR-183-5p expression was reduced in db/db-ICH rats brain tissues. BMSC-EVs ameliorated cranial nerve function, decreased brain water content and repressed inflammatory response by carrying miR-183-5p. BMSC-EVs mitigated HG-Hemin-BV2 cell injury, reduced ROS level and suppressed inflammatory response. miR-183-5p targeted PDCD4. PDCD4 promoted BV2 cell inflammation by activating the NLRP3 pathway. BMSC-EVs inhibited HG-Hemin-BV2 cell inflammation through the miR-183-5p/PDCD4/NLRP3 pathway, and inhibition of miR-183-5p reversed the protective effect of EVs.

CONCLUSION

BMSC-EVs carried miR-183-5p into db/db-ICH rat brain tissues and repressed the NLRP3 pathway by targeting PDCD4, thus alleviating neuroinflammation after diabetic ICH.

MicroRNA-183-5p protects human derived cell line SH-SY5Y cells from mepivacaine-induced injury

With the gradual recognition of the side effects of local anesthetics, the nerve injury caused by local anesthetics has received growing attention. This research intended to delve into miR-183-5p changes in mepivacaine-mediated SH-SY5Y cell injury, as well as its modulatory mechanism on cell apoptosis. RT-qPCR was adopted for assaying miR-183-5p and PDCD4 mRNA expression. Our team respectively transfected miR-183-5p mimic and inhibitor to enhance or inhibit miR-183-5p function. We employed Western blot for detecting PDCD4 protein levels, as well as flow cytometry and Hoechst 33342/PI double staining for determining cell apoptosis rate. Additionally, our crew applied an ELISA kit for measuring TNF-α, IL-1β, IL-6, and IL-8 contents. The level of reactive oxygen species (ROS) production was examined by the Image-iT LIVE Green ROS detection Kit. As well as dual-luciferase reporter experiment for verifying the targeting link of miR-183-5p with PDCD4. In mepivacaine-induced cell apoptosis in SH-SY5Y cells, miR-183-5p expression was down-regulated. TNF-α, IL-1β, IL-6, and IL-8 contents were elevated. The rate of apoptosis increased visibly, cleaved caspase-3 and Bax levels waxed, whereas Bcl-2 level waned. MiR-183-5p could alleviate the damaging impact of mepivacaine. Dual-luciferase reporter experiments demonstrated that miR-183-5p directly targeted PDCD4. Collectively, we concluded that a high concentration of mepivacaine can cause SH-SY5Y cell damage, miR-183-5p functions crucially in mepivacaine-mediated cell damage. This study provides a theoretical basis for elucidating the mechanism of mepivacaine-induced nerve cell damage, and overexpressed miR-183-5p likely become a novel strategy to combat mepivacaine-induced nerve damage.Abbreviations:miRNA: Micro RNA; PDCD4: Programmed Cell Death 4; MDA: Malondialdehyde; SOD: Superoxide Dismutase; ROS: Reactive Oxygen Species; WT: Wild Type; Mut: Mutant; UTR: Untranslated Region; IL-6: Interleukin-6; IL-1β: Interleukin-1β; TNF-α: Tumor Necrosis Factor-α; IL-8: Interleukin-8; COX-2: Cyclooxygenase-2; iNOS: inducible NOS; MEP: Mepivacaine.

Upregulation of miR-499a-5p Decreases Cerebral Ischemia/Reperfusion Injury by Targeting PDCD4

MiR-499a-5p was significantly downregulated in degenerative tissues and correlated with apoptosis. Nonetheless, the biological function of miR-499a-5p in acute ischemic stroke has been still unclear. In this study, we found that the plasma levels of miR-499a-5p were significantly downregulated in 64 ischemic stroke patients and negatively correlated with the National Institutes of Health Stroke Scale score. Then, we constructed cerebral ischemia/reperfusion (I/R) injury in rats after middle cerebral artery occlusion and subsequent reperfusion and oxygen-glucose deprivation and reoxygenation (OGD/R)-treated SH-SY5Y cell model. Transfection with miR-499a-5p mimic was accomplished by intracerebroventricular injection in the in vivo I/R injury model. We further found that miR-499a-5p overexpression decreased infarct volumes and cell apoptosis in the in vivo I/R stroke model using TTC and TUNEL staining. PDCD4 was a direct target of miR-499a-5p by luciferase report assay and Western blotting. Knockdown of PDCD4 reduced the infarct damage and cortical neuron apoptosis caused by I/R injury. MiR-499a-5p exerted neuroprotective roles mainly through inhibiting PDCD4-mediated apoptosis by CCK-8 assay, LDH release assay, and flow cytometry analysis. These findings suggest that miR-499a-5p might represent a novel target that regulates brain injury by inhibiting PDCD4-mediating apoptosis.

Improvement of sensory neuron growth and survival via negatively regulating PTEN by miR-21-5p-contained small extracellular vesicles from skin precursor-derived Schwann cells

Background

Patients with peripheral nerve injury (PNI) often suffer from hypoxic ischemic impairments, in particular when combined with vascular damage, causing neuronal dysfunction and death. Increasing attention has been paid on skin precursor-derived Schwann cells (SKP-SCs), and previous study has shown that SKP-SCs could promote sensory recovery after cell therapy for PNI, resembling the effect of naive SCs, and SKP-SC-derived extracellular vesicles (SKP-SC-EVs) are putatively supposed to be promising therapeutic agents for neural regeneration.

Methods

SKPs were induced to differentiate towards SCs with cocktail factors (N2, neuregulin-1β, and forskolin) in vitro. SKP-SC-EVs were isolated by exoEasy Maxi Kit and characterized by morphology and phenotypic markers of EVs. Rat sensory neurons from dorsal root ganglions (DRGs) were primarily cultured in regular condition or exposed to oxygen-glucose-deprivation (OGD) condition. SKP-SC-EVs were applied to DRGs or sensory neurons, with LY294002 (a PI3K inhibitor) added; the effect on neurite outgrowth and cell survival was observed. Moreover, microRNA (miR) candidate contained in SKP-SC-EVs was screened out, and miR-mimics were transfected into DRG neurons; meanwhile, the negative regulation of PTEN/PI3K/Akt axis and downstream signaling molecules were determined.

Results

It was shown that SKP-SC-EVs could improve the neurite outgrowth of DRGs and sensory neurons. Furthermore, SKP-SC-EVs enhanced the survival of sensory neurons after OGD exposure by alleviating neuronal apoptosis and strengthening cell viability, and the expression of GAP43 (a neuron functional protein) in neurons was upregulated. Moreover, the neuro-reparative role of SKP-SC-EVs was implicated in the activation of PI3K/Akt, mTOR, and p70S6k, as well as the reduction of Bax/Bcl-2 ratio, that was compromised by LY294002 to some extent. In addition, transferring miR-21-5p mimics into sensory neurons could partly protect them from OGD-induced impairment.

Conclusions

Sum up, SKP-SC-EVs could improve neurite outgrowth of DRG sensory neurons in physiological and pathological condition. Moreover, the in vitro therapeutic potential of SKP-SC-EVs on the survival and restoration of OGD-injured sensory neurons was evidenced to be associated with miR-21-5p contained in the small EVs and miR-21-5p/PTEN/PI3K/Akt axis.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-020-02125-4.

Overexpression of circRNA circUCK2 Attenuates Cell Apoptosis in Cerebral Ischemia-Reperfusion Injury via miR-125b-5p/GDF11 Signaling

Circular RNAs (circRNAs) are expressed at high levels in the brain and are involved in various central nervous system diseases. However, the potential role of circRNAs in ischemic stroke-associated neuronal injury remains largely unknown. Herein, we uncovered the function and underlying mechanism of the circRNA UCK2 (circUCK2) in ischemia stroke. The oxygen-glucose deprivation model in HT-22 cells was used to mimic ischemia stroke in vitro. Neuronal viability and apoptosis were determined by Cell Counting Kit-8 (CCK-8) assays and TUNEL (terminal deoxynucleotidyltransferase-mediated deoxyuridine triphosphate nick end labeling) staining, respectively. Middle cerebral artery occlusion was conducted to evaluate the function of circUCK2 in mice. The levels of circUCK2 were significantly decreased in brain tissues from a mouse model of focal cerebral ischemia and reperfusion. Upregulated circUCK2 levels significantly decreased infarct volumes, attenuated neuronal injury, and improved neurological deficits. circUCK2 reduced oxygen glucose deprivation (OGD)-induced cell apoptosis by regulating transforming growth factor β (TGF-β)/mothers against decapentaplegic homolog 3 (Smad3) signaling. Furthermore, circUCK2 functioned as an endogenous miR-125b-5p sponge to inhibit miR-125b-5p activity, resulting in an increase in growth differentiation factor 11 (GDF11) expression and a subsequent amelioration of neuronal injury. Consequently, these findings showed that the circUCK2/miR-125b-5p/GDF11 axis is an essential signaling pathway during ischemia stroke. Thus, the circRNA circUCK2 may serve as a potential target for novel treatment in patients with ischemic stroke.

Protective Effect of miR-340-5p against Brain Injury after Intracerebral Hemorrhage by Targeting PDCD4

OBJECTIVE

Intracerebral hemorrhage (ICH) is a common cerebrovascular disease. Increasing evidence has documented the crucial role of microRNAs in ICH. The present study aimed to investigate the role and underlying mechanism of miR-340-5p in ICH.

METHODS

The collagenase-induced ICH rat model was established. The neurological function of rats and the cerebral water content of rat brain tissue were measured to assess the brain injury. BV-2 cells were recruited and treated by LPS to mimic ICH-induced inflammatory response. qRT-PCR was used for the measurement of miR-340-5p. The protein levels of TNF-α, IL-6, and IL-1β were detected using ELISA. Luciferase reporter gene assay was performed to confirm the target gene.

RESULTS

Downregulation of miR-340-5p was detected in the serum of ICH patients and the brain tissues of ICH rats. Overexpression of miR-340-5p reversed the influence of ICH on the neurological function score and cerebral water content and inhibited the production of proinflammatory cytokines (TNF-α, IL-6, and IL-1β), which were induced by ICH in vivo. In in vitro study, levels of TNF-α, IL-6, and IL-1β were significantly enhanced in cells after LPS treatment, but these increases were eliminated by overexpression of miR-340-5p. PDCD4 was a direct target gene of miR-340-5p.

CONCLUSION

miR-340-5p protects against brain injury after ICH. miR-340-5p might exert an anti-inflammatory effect during the occurrence of ICH via targeting PDCD4.

miR-339 Promotes Hypoxia-Induced Neuronal Apoptosis and Impairs Cell Viability by Targeting FGF9/CACNG2 and Mediating MAPK Pathway in Ischemic Stroke

Ischemic stroke (IS) is a common cerebrovascular disease characterized by insufficient blood blow to the brain and the second leading cause of death as well as disability worldwide. Recent literatures have indicated that abnormal expression of miR-339 is closely related to IS. In this study, we attempted to assess the biological function of miR-339 and its underlying mechanism in IS. By accessing the GEO repository, the expression of miR-339, FGF9, and CACNG2 in middle cerebral artery occlusion (MCAO) and non-MCAO was evaluated. PC12 cells after oxygen-glucose deprivation/reoxygenation (OGD/R) treatment were prepared to mimic in vitro the IS model. The levels of miR-339, FGF9, CACNG2, and MAPK-related markers were quantitatively measured by qRT-PCR and Western blot. CCK-8 and flow cytometry analyses were performed to examine cell viability and apoptosis, respectively. IS-related potential pathways were identified using KEGG enrichment analysis and GO annotations. Bioinformatics analysis and dual-luciferase reporter assay were used to predict and verify the possible target of miR-339. Our results showed that miR-339 expression was significantly increased in MCAO and OGD/R-treated PC12 cells. Overexpression of miR-339 inhibited cell viability of PC12 cells subjected to OGD/R treatment. FGF9 and CACMG2 are direct targets of miR-339 and can reverse the aggressive effect of miR-339 on the proliferation and apoptosis of OGD/R-treated PC12 cells. Moreover, miR-339 mediated the activation of the MAPK pathway, which was inhibited by the FGF9/CACNG2 axis in PC12 cells treated by OGD/R stimulation. In summary, these findings suggested that miR-339 might act as a disruptive molecule to accelerate the IS progression via targeting the FGF9/CACNG2 axis and mediating the MAPK pathway.

Mu-Xiang-You-Fang protects PC12 cells against OGD/R-induced autophagy via the AMPK/mTOR signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Mu-Xiang-You-Fang (MXYF) is a classic prescription of Hui medicine. It is composed of five herbs and has been used to treat ischemic stroke for many years. However, the potential pharmacological mechanisms of MXYF remain unclear. The present research is aimed to investigate the protective effect and possible mechanisms of MXYF treatment in an in vitro model of cerebral ischemia-reperfusion injury.

MATERIALS AND METHODS

An oxygen-glucose deprivation and reperfusion (OGD/R) model of PC12 cells was established. The effect of MXYF on the cell viability after OGD/R injury was determined using a cell counting kit (CCK-8) assay. The colorimetric method was used to determine the lactate dehydrogenase (LDH) leakage rate. The calcium concentration was determined by the chemical fluorescence method, and mitochondrial membrane potential was determined using flow cytometry. Monodansylcadaverine (MDC) staining and electron microscopic analysis were then conducted to detect autophagy after oxygen-glucose deprivation and reperfusion in PC12 cells. Immunofluorescence and western blot analyses were used to detect the expression of proteins associated with autophagy.

RESULTS

It was found that MXYF (1, 2, 4 μg/mL) could significantly increase cell viability and mitochondrial membrane potential and decrease the calcium concentration and LDH release rate in PC12 cells. After OGD/R injury in PC12 cells, the number of autophagosomes and autophagolysosome significantly increased. MXYF (4 μg/mL) inhibited the autophagy induced by OGD/R and inhibited the expression of LC3, beclin1, p-AMPK, and ULK1. In contrast, the expression of p-mTOR, p-p70s6k, and p62 was significantly enhanced.

CONCLUSIONS

These findings suggest that MXYF inhibits autophagy after OGD/R-induced PC12 cell injury through the AMPK-mTOR pathway. Thus, MXYF might have therapeutic potential in treating ischemic stroke.