Fat mass and obesity-associated protein regulates RNA methylation associated with spatial cognitive dysfunction after chronic cerebral hypoperfusion.

RNA methylation can epigenetically regulate learning and memory. However, it is unclear whether RNA methylation plays a critical role in the pathophysiology of Vascular dementia (VD). Here, we report that expression of the fat mass and obesity associated gene (FTO), an RNA demethylase, is downregulated in the hippocampus in models of VD. Through prediction and dual-luciferase reporters validation studies, we observed that miRNA-711 was upregulated after VD and could bind to the 3'-untranslated region of FTO mRNA and regulate its expression in vitro. Methylated RNA immunoprecipitation (MeRIP)-qPCR assay and functional study confirmed that Syn1 was an important target gene of FTO. This suggests that FTO is an important regulator of Syn1. FTO upregulation by inhibition of miR-711 in the hippocampus relieves synaptic association protein and synapse deterioration in vivo, whereas FTO downregulation by miR-711 agomir in the hippocampus leads to aggravate the synapse deterioration. FTO upregulation by inhibition of miR-711 relieves cognitive impairment of rats VD model, whereas FTO downregulation by miR-711 deteriorate cognitive impairment. Our findings suggest that FTO is a regulator of a mechanism underlying RNA methylation associated with spatial cognitive dysfunction after chronic cerebral hypoperfusion.

Muscone alleviates neuronal injury via increasing stress granules formation and reducing apoptosis in acute ischemic stroke.

As the main bioactive component of musk, muscone has been reported to have marked protective effects in treating acute ischemic stroke (AIS). However, the specific anti-stroke mechanism of muscone still needs further research. In the current investigation, the PC12 cells OGD/R and the rat transient MCAO/R models were utilized as the AIS models. Serum hepatic and renal functional indexes (ALT, AST, BUN, and Cr) and cell viability were determined to select the appropriate muscone concentrations for in vitro and in vivo experiments. TTC, Hematoxylin and eosin (H&E), and Live/Dead staining were utilized to evaluate the protective effects of muscone in injured tissues and cells. Western blotting analysis, TUNEL staining, propidium iodide, and annexin V staining were applied to detect the anti-apoptotic effect of muscone. Double-label immunofluorescence staining of T-cell intracellular antigen-1 (TIA1) and Ras-GAP SH3 domain-binding protein 1 (G3BP1) was performed to observe whether muscone regulated the SG formation level. Molecular docking, TIA1 silencing and TIA1 overexpression experiments were employed to investigate the molecular mechanism underlying the regulation of SG formation by muscone. The 2, 3, 5-Triphenyl-tetrazolium chloride (TTC) staining and live/dead staining showed the AIS injury level of MCAO/R rat and the OGD/R PC12 cells were attenuated by muscone administration. The muscone significantly minimized the apoptosis rate in MCAO/R rats and OGD/R PC12 cells following flow cytometry analysis, western blotting analysis, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The double-label immunofluorescence staining data revealed that muscone promoted the SG formation level in OGD/R PC12 cells and the cortex MCAO/R rats. The results of molecular docking, TIA1 silencing and TIA1 overexpression experiments revealed that muscone could bind to TIA1 protein and regulate its expression level, thereby promoting the formation of stress granules and exerting a protective effect against AIS injury. This study indicated that the significant protective effect of muscone in reducing apoptosis levels might be via promoting SG formation under AIS conditions. This study further explores the therapeutic effect and anti-apoptosis mechanism of muscone in AIS, which may provide a potential candidate drug for the clinical treatment of AIS injury.

What exactly does the PfK13 C580Y mutation in Plasmodium falciparum influence?

BACKGROUND: The emergence and spread of artemisinin resistance threaten global malaria control and elimination goals, and encourage research on the mechanisms of drug resistance in malaria parasites. Mutations in Plasmodium falciparum Kelch 13 (PfK13) protein are associated with artemisinin resistance, but the unique or common mechanism which results in this resistance is unclear. METHODS: We analyzed the effects of the PfK13 mutation on the transcriptome and proteome of P. falciparum at different developmental stages. Additionally, the number of merozoites, hemozoin amount, and growth of P. falciparum 3D7C580Y and P. falciparum 3D7WT were compared. The impact of iron supplementation on the number of merozoites of P. falciparum 3D7C580Y was also examined. RESULTS: We found that the PfK13 mutation did not significantly change glycolysis, TCA, pentose phosphate pathway, or oxidative phosphorylation, but did reduce the expression of reproduction- and DNA synthesis-related genes. The reduced number of merozoites, decreased level of hemozoin, and slowed growth of P. falciparum 3D7C580Y were consistent with these changes. Furthermore, adding iron supply could increase the number of the merozoites of P. falciparum 3D7C580Y. CONCLUSIONS: These results revealed that the PfK13 mutation reduced hemoglobin ingestion, leading to artemisinin resistance, likely by decreasing the parasites' requirement for haem and iron. This study helps elucidate the mechanism of artemisinin resistance due to PfK13 mutations.

Chrysophanol improves memory impairment and cell injury by reducing the level of ferroptosis in Aß25-35 treated rat and PC12 cells.

Alzheimer's disease (AD) is a common age-related chronic and neurodegenerative disease that has become a global health problem. AD pathogenesis is complex, and the clinical efficacy of commonly used anti-AD drugs is suboptimal. Recent research has revealed a close association between AD-induced damage and the activation of ferroptosis signaling pathways. Chrysophanol (CHR) the principal medicinal component of Rhubarb, has been reported to have anti-AD effects and can reduce ROS levels in AD-damaged models. AD has been linked to the activation of ferroptosis signaling pathways, which has an important feature of higher levels of reactive oxygen species (ROS). Therefore, the present study explored whether CHR had an anti-AD effect by regulating the ferroptosis levels in AD injury models. Morris water maze, novel object recognition test, Y-maze test, Hematoxylin-eosin (H&E) staining, western blotting, ROS measurement, GPx activity measurement, LPO measurement, transmission electron microscopy, live/dead cell staining were used to investigate the changes in spatial memory level and ferroptosis level in AD model, and the intervention effect of CHR. CHR improved the spatial memory level of AD rat models, reduced the level of hippocampal neuron damage, and improved the survival rate of PC12 cells damaged by ß-amyloid (Aß). Meanwhile, CHR increased glutathione peroxidase-4 (GPX4) protein expression, GPx activity, and GSH, decreased ROS and LPO levels in AD rat models and Aß-damaged PC12 cells, and improved mitochondrial pathological damage. Our findings suggest that CHR may play a protective role in AD injury by lowering ferroptosis levels, which may provide a potential pathway for developing drugs for AD. However, the mechanism of CHR's role requires further investigation.

Phosphorylation of MAP 1A regulates hyperphosphorylation of Tau in Alzheimer's disease model.

BACKGROUND AND PURPOSE: Hyperphosphorylation of Tau is one of the important pathological features of Alzheimer's disease (AD). Therefore, studying the mechanisms behind Tau hyperphosphorylation is crucial in exploring the pathogenesis of neurological damage in AD. METHODS: In this study, after the establishment of rat models of AD, quantitative phosphoproteomics and proteomics were performed to identify proteins, showing that phosphorylation of microtubule associated protein 1A (MAP 1A) was lower in the model group. Western blot confirmed the changes of MAP 1A in the SD rats, APP/PS1 transgenic mice and cell AD models. To further study the molecular mechanism of recombinant MAP 1A phosphorylation affecting Tau phosphorylation, interfering siRNA-MAP 1A and protein immunoprecipitation reaction analysis were performed in AD cell models. RESULTS: Cyclin-dependent kinase 5 (CDK5) showed reduced binding to MAP 1A and increased binding to Tau, resulting in a decrease in phosphorylated MAP 1A (p-MAP 1A) and an increase in phosphorylated Tau (p-Tau), and MAP 1A silencing promoted binding of CDK5-Tau and increased Tau phosphorylation, thereby reducing the cell survival rate. CONCLUSIONS: In summary, we found that p-MAP 1A downregulation associated with p-Tau upregulation was due to their altered binding forces to CDK5, and MAP 1A could enhance autophosphorylation by competitive binding to CDK5 and antagonise Tau phosphorylation. This leads to neuronal protection and reducing tissue damage levels in AD, which can help better understand the mechanisms of AD pathogenesis.

Snap25 attenuates neuronal injury via reducing ferroptosis in acute ischemic stroke.

Due to the limited clinical treatment options for acute ischemic stroke (AIS), there is still an urgent requirement for in-depth research on the pathogenesis of AIS and the development of efficient therapeutic approaches and agents. Literature reports reveal that ferroptosis may play an important role in the pathogenesis of AIS. However, the specific mechanism and the molecular target of action of ferroptosis in AIS injury remains unclear. In this study, we constructed AIS rat and PC12 cell models. We applied RNAi-mediated knockdown and gene overexpression technologies to investigate whether Snap25 (Synaptosome-associated protein 25 kDa) can regulate the level of AIS damage by interfering with the level of ferroptosis in AIS. The in vivo and in vitro results revealed that the level of ferroptosis significantly increased in the AIS model. Snap25 gene overexpression significantly inhibited the ferroptosis level and decreased the AIS damage and OGD/R injury level in the model group. Snap25 silencing exacerbated the ferroptosis level and aggravated OGD/R injury in PC12 cells. The overexpression and silencing of Snap25 can significantly affect the expression level of ROS, suggesting that the regulatory effect on the ROS level may be an important factor in regulating ferroptosis in AIS by Snap25. In conclusion, the findings of this study suggested that Snap25 has a protective effect against ischemia/reperfusion injury by reducing ROS levels and ferroptosis levels. This study further confirmed the involvement of ferroptosis in the process of AIS injury and explored the regulatory mechanism of Snap25 on the ferroptosis level in AIS, which could provide a promising therapeutic target for ischemic stroke treatment.

Why is Babesia not killed by artemisinin like Plasmodium?

Babesia spp. are intraerythrocytic apicomplexans that digest and utilize red blood cells in a similar way to intraerythrocytic Plasmodium spp., but unlike the latter, are not sensitive to artemisinin. A comparison of Babesia and Plasmodium genomes revealed that Babesia genomes, which are smaller than those of Plasmodium, lack numerous genes, and especially haem synthesis-related genes, that are found in the latter. Single-cell sequencing analysis showed that the different treatment groups of Babesia microti with expressed pentose phosphate pathway-related, DNA replication-related, antioxidation-related, glycolysis-related, and glutathione-related genes were not as sensitive to artemether as Plasmodium yoelii 17XNL. In particular, pentose phosphate pathway-related, DNA replication-related, and glutathione-related genes, which were actively expressed in P. yoelii 17XNL, were not actively expressed in B. microti. Supplying iron in vivo can promote the reproduction of B. microti. These results suggest that Babesia spp. lack a similar mechanism to that of malaria parasites through which the haem or iron in hemoglobin is utilized, and that this likely leads to their insensitivity to artemisinin.

Atractylodes lancea volatile oils target ADAR2-miR-181a-5p signaling to mesenchymal stem cell chondrogenic differentiation.

Atractylodeslancea Rhizoma (Rhizoma atractylodis [RA]) has long been recommended for the treatment of arthritis in traditional Chinese medicine, but its mechanism of action is still unclear. RA contains a large amount of Atractylodes lancea volatile oils (Atr). In this study, we investigated whether Atr can promote mesenchymal stem cells (MSCs) chondrogenic differentiation. The Atr were extracted from RA by steam distillation method, and the effect of Atr on MSCs was detected by the CCK8 assay. The optimal concentration of Atr for MSCs cultivation was 3 µg/ml. The differentially expressed miR-181a-5p was screened by miRNA microarray assay, and its mimics and inhibitors were transfected into MSCs. It was found that the inhibitor of miR-181a-5p could upregulate cartilage-specific genes such as SOX9, COL2A1, and ACAN. Meanwhile, we also found that the expression of gene editing enzyme ADAR2 was significantly increased in the chondrogenic differentiation of MSCs induced by Atr, and the bases of precursor sequence of miR-181a-5p were changed from A to G. After ADAR2 deletion, the expression of cartilage-specific genes was significantly down-regulated and the precursor sequence bases of miR-181a-5p were not changed. Bioinformatics analysis revealed that the predicted target gene of miR-181a-5p was yingyang1 (YY1), and the targeting relationship was verified by dual-luciferase reporter assay. After deleting YY1, the expression of cartilage-specific genes was significantly down-regulated. In conclusion, our study demonstrated that Atr can promote chondrogenic differentiation of MSC through regulation of the ADAR2-miR-181a-5p signaling pathway. This may provide a new insight into the possible mechanism of traditional Chinese medicine (Atr) in treating inflammatory joint diseases.

Moxibustion Protects Dopaminergic Neurons in Parkinson's Disease through Antiferroptosis.

Ferroptosis is associated with neural degeneration of dopaminergic neurons in Parkinson's disease (PD). However, how to control the level of ferroptosis in PD remains unclear. Clinically, moxibustion has been used to treat PD and has an apparent therapeutic effect on improving the motor symptoms of PD. In the present study, the PD rat model was constructed by two-point stereotactic 6-hydroxydopamine injection. Then, moxibustion was used to treat the PD rats. The expression of glutathione peroxidase 4 (GPX4) and Ferritin Heavy Chain 1 (FTH1), the level of reactive oxygen species (ROS), and the morphology of mitochondrial were detected to evaluate the level of ferroptosis. The results showed that moxibustion treatment of Shi's moxa sticks could reduce the behavioral score, alleviate the level of ferroptosis, decrease mitochondrial damage, and improve dopaminergic neuron survival. In conclusion, the present study results indicated that Shi's moxa sticks could effectively suppress the level of ferroptosis, thereby improving the survival of dopaminergic neurons in the SNpc of PD rats, which may provide a promising complementary and alternative therapy for PD patients.

Niujiaodihuang Detoxify Decoction inhibits ferroptosis by enhancing glutathione synthesis in acute liver failure models.

ETHNOPHARMACOLOGICAL RELEVANCE: Niujiaodihuang Detoxify Decoction (NDD) is an integrated traditional Chinese medicine prescription that has been used as a therapeutic agent for the treatment of acute liver failure (ALF). However, the mechanisms underlying its action remain unclear. AIM OF THE STUDY: To determine the protective effect of NDD on D-galactosamine/lipopolysaccharide (D-GalN/LPS)-induced ALF and explore the underlying mechanisms. MATERIALS AND METHODS: We characterized the NDD fingerprint by HPLC and established D-GalN/LPS-induced ALF models in Sprague-Dawley rats and LO2 cells. Next, we measured the protective and antiferroptotic effects of NDD in vivo and in vitro. To further investigate the molecular mechanisms underlying the effects of NDD, we performed metabolomic analysis of the liver tissue using LC-MS/MS. RESULTS: Results of serum biochemical analysis, liver histopathology, and cell viability showed that NDD effectively relieved the liver injury. It reduced the accumulation of labile iron and alleviated lipid peroxidation by enhancing GPX4 activity. The mitochondrial morphology indicated that NDD exerted its hepatoprotective effect through an antiferroptotic activity. Metabolomic analysis showed that NDD treatment increased the levels of cysteine, decreased those of glutamate, and ameliorated the D-GalN/LPS-induced reduction in the levels of glutathione (GSH). The results for intracellular levels of reduced (GSH) and oxidized (GSSG) glutathione were consistent with those of metabolomic analysis. CONCLUSION: Our findings indicate that NDD exerts hepatoprotective activity by evoking the reprogramming of GSH metabolism, and thereby, inhibiting ferroptosis.

Super-enhancer-driven Sorting Nexin 5 expression promotes dopaminergic neuronal ferroptosis in Parkinson's disease models.

Parkinson's disease (PD) is the second most prevalent neurodegenerative disease worldwide. Recent studies revealed that the ferroptosis pathway is involved in the death process of dopaminergic neurons in PD. The aberrant endosomal sorting pathway, which results in aberrant iron level in eukaryotic cells, may serve a role in the ferroptosis pathway in PD condition. However, its specific molecular mechanisms remained unclear. In the present study, we performed chromatin immunoprecipitation (ChIP) assay, the rank ordering of super-enhancers (ROSE) algorithm, and RNA interference (RNAi) to explore the regulatory mechanism of PD-specific super-enhancer (SE) in the endosomal sorting pathway and ferroptosis pathway of 6-OHDA-lesioned rats and cells. The ChIP assay and ROSE algorithm results showed that there are specific SEs expression in 6-OHDA-lesioned SNc of PD rats, and the most significant expression gene is Sorting Nexin 5 (SNX5). SNX5 silencing by RNAi experiments significantly decreased the level of ferroptosis in 6-OHDA-lesioned PC12 cells, suggesting the correlation between the SNX5, ferroptosis, and PD. In conclusion, this study investigated the mechanism by which PD-specific SE driven SNX5 promoted the ferroptosis level in PD models. This study further improved the understanding of the mechanism of ferroptosis during PD injury and provided potential therapeutic targets and clinical diagnostic markers in PD condition.

Identification of Potential Pathogenic Super-Enhancers-Driven Genes in Pulmonary Fibrosis.

Abnormal fibroblast differentiation into myofibroblast is a crucial pathological mechanism of pulmonary fibrosis (PF). Super-enhancers, a newly discovered cluster of regulatory elements, are regarded as the regulators of cell identity. We speculate that abnormal activation of super-enhancers must be involved in the pathological process of PF. This study aims to identify potential pathogenic super-enhancer-driven genes in PF. Differentially expressed genes (DEGs) in PF mouse lungs were identified from a GEO dataset (GDS1492). We collected super-enhancers and their associated genes in human lung fibroblasts and mouse embryonic fibroblasts from SEA version 3.0, a network database that provides comprehensive information on super-enhancers. We crosslinked upregulated DEGs and super-enhancer-associated genes in fibroblasts to predict potential super-enhancer-driven pathogenic genes in PF. A total of 25 genes formed an overlap, and the protein-protein interaction network of these genes was constructed by the STRING database. An interaction network of transcription factors (TFs), super-enhancers, and associated genes was constructed using the Cytoscape software. Gene enrichment analyses, including KEGG pathway and GO analysis, were performed for these genes. Latent transforming growth factor beta (TGF-ß) binding protein 2 (LTBP2), one of the predicted super-enhancer-driven pathogenic genes, was used to verify the predicted network's accuracy. LTBP2 was upregulated in the lungs of the bleomycin-induced PF mouse model and TGF-ß1-stimulated mouse and human fibroblasts. Myc is one of the TFs binding to the LTBP2 super-enhancer. Knockout of super-enhancer sequences with a CRISPR/Cas9 plasmid or inhibition of Myc all decreased TGF-ß1-induced LTBP2 expression in NIH/3 T3 cells. Identifying and interfering super-enhancers might be a new way to explore possible therapeutic methods for PF.

Associations of hand washing frequency with the incidence of illness: a systematic review and meta-analysis.

BACKGROUND: Hand hygiene is one of the ways to prevent the spread of diseases. Our aim was to explore the relationship between hand washing frequency and the impact on disease, and give recommendations on the number of times to wash hands. METHODS: We searched seven electronic databases from their inception to April 11, 2020, and reference lists of related reviews for all studies on hand washing frequency and disease prevention. The Review Manager 5.3. software was used to conduct a meta-analysis. We assessed the risk of bias of included studies, and quality of evidence of the main findings. RESULTS: A total of eight studies were included. The results of the meta-analysis showed that there was no statistical significance between the effect of disease prevention and washing more than 4 times/day compared to not [odds ratio (OR) =0.61, 95% confidence interval (CI): 0.37 to 1.01]. The results of a case-control study showed that compared with hand washing ≤4 times/day, hand washing 5-10 times/day (OR =0.75, 95% CI: 0.63 to 0.91) and hand washing >10 times/day (OR =0.65, 95% CI 0.53 to 0.80) could reduce the risk of disease infection. There was no statistical significance advantage to hand washing more than 10 times/day compared to 5-10 times/day (OR =0.86, 95% CI: 0.70 to 1.06). Comparing hand washing ≤10 times/day with hand washing >10 times/day, increased hand washing was a protective factor against infection (OR =0.59, 95% CI: 0.36 to 0.97). CONCLUSIONS: The more frequently hands were washed, the lower risk of disease. So far however, there is no high-quality evidence indicating the best range of hand washing frequency for disease prevention.

miR­335 promotes ferroptosis by targeting ferritin heavy chain 1 in in vivo and in vitro models of Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disease characterized by the selective loss of dopaminergic neurons in the substantia nigra (SN). In a previous study, the authors demonstrated that ferritin heavy chain 1 (FTH1) inhibited ferroptosis in a model of 6­hydroxydopamine (6­OHDA)­induced PD. However, whether and how microRNAs (miRNAs/miRs) modulate FTH1 in PD ferroptosis is not yet well understood. In the present study, in vivo and in vitro models of PD induced by 6­OHDA were established. The results in vivo and in vitro revealed that the levels of the ferroptosis marker protein, glutathione peroxidase 4 (GPX4), and the PD marker protein, tyrosine hydroxylase (TH), were decreased in the model group, associated with a decreased FTH1 expression and the upregulation of miR­335. In both the in vivo and in vitro models, miR­335 mimic led to a lower FTH1 expression, exacerbated ferroptosis and an enhanced PD pathology. The luciferase 3'­untranslated region reporter results identified FTH1 as the direct target of miR­335. The silencing of FTH1 in 6­OHDA­stimulated cells enhanced the effects of miR­335 on ferroptosis and promoted PD pathology. Mechanistically, miR­335 enhanced ferroptosis through the degradation of FTH1 to increase iron release, lipid peroxidation and reactive oxygen species (ROS) accumulation, and to decrease mitochondrial membrane potential (MMP). On the whole, the findings of the present study reveal that miR­335 promotes ferroptosis by targeting FTH1 in in vitro and in vivo models of PD, providing a potential therapeutic target for the treatment of PD.

RNA Binding Protein Motif 3 Inhibits Oxygen-Glucose Deprivation/Reoxygenation-Induced Apoptosis Through Promoting Stress Granules Formation in PC12 Cells and Rat Primary Cortical Neurons.

As a sensitive cold-shock protein, RNA binding protein motif 3 (RBM3) exhibits a neuroprotective function in the condition of brain injury. However, how RBM3 is involved in acute ischemic stroke by affecting stress granules (SGs) remains unclear. Here, we established an oxygen-glucose deprivation/reperfusion (OGD/R) model in rat primary cortical neurons and PC12 cells to explore the potential mechanism between RBM3 and SG formation in acute ischemic/reperfusion (I/R) condition. The immunofluorescence results showed that the SG formation significantly decreased in rat primary cortical neurons and PC12 cells during the reperfusion period after 6 h of OGD stimulation. The western blot results, flow cytometry analysis, and cell viability assessment showed that the RBM3 expression and ratio of cell viability significantly decreased, while the rate of apoptosis increased in PC12 cells during the reperfusion period after 6 h of OGD stimulation. Co-immunoprecipitation (Co-IP) and immunofluorescence indicated that RBM3 and GTPase-activating protein-binding protein 1 (G3BP1) colocalized cytoplasm of PC12 cells after 6 h of OGD stimulation when the SGs formation reached the highest level. Besides, overexpression and knockdown of the RBM3 were achieved via plasmid transfection and CRISPR-Cas9 technology, respectively. The results of overexpression and knockdown of RBM3 gene illustrated the pivotal role of RBM3 in affecting SG formation and apoptosis level in OGD-treated PC12 cells. In conclusion, RBM3 could combine with G3BP1 resulted in increasing stress granules generation in rat primary cortical neurons and PC12 cells after 6 h of oxygen-glucose deprivation (OGD) injury, which ultimately reduced the apoptosis in OGD-induced cells. Our study may enable a new promising target for alleviating ischemia-reperfusion injury in cells.

Methyltransferase 3 Mediated miRNA m6A Methylation Promotes Stress Granule Formation in the Early Stage of Acute Ischemic Stroke.

The modification of methyltransferase-like (METTL) enzymes plays important roles in various cellular responses by regulating microRNA expression. However, how m6A modification is involved in stress granule (SG) formation in the early stage of acute ischemic stroke by affecting the biogenesis processing of microRNAs remains unclear. Here, we established a middle cerebral artery occlusion (MCAO) model in rats and an oxygen-glucose deprivation/reperfusion (OGD/R) model in primary cortical neurons and PC12 cells to explore the potential mechanism between m6A modification and SG formation. The in vivo results showed that the level of infarction and apoptosis increased while SG formation decreased significantly within the ischemic cortex with improved reperfusion time after 2 h of ischemia. Consistent with the in vivo data, an inverse association between the apoptosis level and SG formation was observed in PC12 cells during the reperfusion period after 6 h of OGD stimulation. Both in vivo and in vitro results showed that the expression of METTL3 protein, m6A and miR-335 was significantly decreased with the reperfusion period. Overexpression of the METTL3 and METTL3 gene-knockdown in PC12 cells were achieved via plasmid transfection and CRISPR-Cas9 technology, respectively. Overexpression or knockdown of METTL3 in oxygen-glucose deprivation of PC12 cells resulted in functional maturation of miR-335, SG formation and apoptosis levels. In addition, we found that miR-335 enhanced SG formation through degradation of the mRNA of the eukaryotic translation termination factor (Erf1). In conclusion, we found that METTL3-mediated m6A methylation increases the maturation of miR-335, which promotes SG formation and reduces the apoptosis level of injury neurons and cells, and provides a potential therapeutic strategy for AIS.

miR­134­5p/Foxp2/Syn1 is involved in cognitive impairment in an early vascular dementia rat model.

Forkhead box P2 (Foxp2) is a transcription factor involved in vocal learning. However, the number of previous studies that have investigated the role of Foxp2 in early vascular dementia (VD) is limited. The aim of the present study was to determine whether microRNA (miR)­134­5p/Foxp2 contributes to cognitive impairment in a chronic ischemia­induced early VD model. miR­134­5p was found to be significantly increased in the cortex in a rat VD model. Intracerebroventricular injection of miR­134­5p antagomir into VD rats prevented the loss of synaptic proteins and the development of cognitive impairment phenotypes. Histopathological analysis revealed that miR­134­5p aggravated cognitive impairment in VD rats through damage to cortical neurons and loss of synaptic proteins. Bioinformatics analysis predicted that miR­134­5p targets Foxp2 mRNA. Dual luciferase analysis and western blotting supported the prediction that miR­134­5p targets Foxp2. Furthermore, the silencing of Foxp2 significantly inhibited the effect of miR­134­5p on synaptic protein loss. Chromatin immunoprecipitation­quantitative polymerase chain reaction analysis indicated that Foxp2 binds to the synapsin I (Syn1) promoter at ­400/­600 bp upstream of the transcription start site. In conclusion, the miR­134­5p/Foxp2/Syn1 axis was found to contribute to cognitive impairment in a chronic ischemia­induced early VD model, which may enable the development of new therapeutic strategies for the prevention and treatment of VD.

miR­335 promotes stress granule formation to inhibit apoptosis by targeting ROCK2 in acute ischemic stroke.

Under harmful environmental conditions, stress granules (SGs), macromolecular aggregates that are associated with cell survival and death, are produced in the eukaryotic cytoplasm. However, whether and how microRNAs (miRNAs/miRs) modulate SG formation induced by acute ischemic stroke has not been investigated. In the present study, a rat model of middle cerebral artery occlusion (MCAO) was utilized and miRNA array profiling and reverse transcription­quantitative polymerase chain reaction were performed. The results revealed that miR­335 was downregulated during acute ischemic stroke, which was concomitant with reduced SG formation, enhanced apoptosis levels and increased Rho associated protein kinase 2 (ROCK2) expression. In the MCAO rat and serum­free cell models, miR­335 treatment upregulated SG formation, alleviated the ischemia­induced infarction, and decreased ROCK2 protein expression and apoptosis levels. By contrast, when compared with miR­335 treatment, the inhibition of miR­335 resulted in reduced SG formation and higher ROCK2 expression and apoptosis levels. Target prediction analysis and luciferase 3'­untranslated region reporter assay identified ROCK2 as the direct target of miR­335. Furthermore, ROCK2 silencing enhanced SG formation and attenuated the level of apoptosis in the serum­free cell model. In addition, ROCK2 silencing markedly inhibited the effect of miR­335 on SG formation and apoptosis levels. Unexpectedly, the phosphorylation of T­cell intracellular antigen­1 was significantly inhibited by miR­335 in the MCAO rat model, which provides a reasonable explanation for the promotional effect of miR­335 on SG formation by specifically targeting ROCK2. In conclusion, these results demonstrate that miR­335 promotes SG formation and inhibits apoptosis by reducing ROCK2 expression in acute ischemic stroke, which provides a possible therapeutic target for brain injury.

MicroRNA-210-5p Contributes to Cognitive Impairment in Early Vascular Dementia Rat Model Through Targeting Snap25.

Vascular dementia (VD) is the most common form of dementia in elderly people. However, little is understood about the role of microRNAs (miRNAs) involved in cognitive impairment in early VD. Here, a VD model induced by chronic cerebral ischemia and fetal bovine serum (FBS)-free cell model that detects synapse formation was established to investigate the function of miRNAs in early VD. The microarray analysis and real-time reverse transcription polymerase chain reaction (RT-PCR) showed that miR-210-5p increased significantly in the hippocampus of rats with 4 weeks of ischemia. The VD model rats also displayed significant cognitive deficits and synaptic loss. The overexpression of miR-210-5p decreased the synaptic number in primary hippocampal neurons, whereas specific suppression of miR-210-5p resulted in the formation of more synapses. Additionally, intracerebroventricular (ICV) injection of miR-210-5p agomir to VD rats aggravated phenotypes of cognitive impairment and synaptic loss. These VD-induced phenotypes were effectively attenuated by miR-210-5p antagomir. Moreover, bioinformatic prediction revealed that synaptosomal-associated protein of 25 KDa (Snap25) mRNA is targeted by miR-210-5p. The miR-210-5p decreased the luciferase activities of 3' untranslated region (3'UTR) of Snap25 mRNA. Mutation of predicted miR-210-5p binding sites in the 3' UTR of Snap25 mRNA abolished the miR-210-5p-induced decrease in luciferase activity. Western blot and immunofluorescence staining confirmed that miR-210-5p targets Snap25. Finally, RT-quantitative PCR (qPCR) and immunofluorescence staining detected that miR-210-5p agomir downregulated Snap25 expression in the cornu ammonis1 (CA1) region of hippocampi in VD rats, whereas miR-210-5p antagomir upregulated Snap25 expression. Altogether, miR-210-5p contributes to cognitive impairment in chronic ischemia-induced VD model through the regulation of Snap25 expression, which potentially provides an opportunity to develop a new therapeutic strategy for VD.

MicroRNA-125a-3p is involved in early behavioral disorders in stroke-afflicted rats through the regulation of Cadm2.

Ischemic strokes carry a significant risk of mortality and recurrent vascular events. Recent studies suggest that changes in microRNAs (miRNAs or miRs) may affect the development of the stroke. However, few studies have investigated the role of miRNAs in behavioral disorder in early stroke. In the present study, animal models of middle cerebral artery occlusion (MCAO) are used, as well as a cell model of neurite outgrowth to further investigate the role of miRNAs in targeting synapse-associated proteins expression in early stroke. The authors used miRNA expression microarrays on RNA extracted from the cortex tissue samples from the rats of MCAO and control rats. Reverse transcription­quantitative polymerase chain reaction was conducted to verify the candidate miRNAs discovered by microarray analysis. Data indicated that miR­125a was significantly increased in the cortex of the model of MCAO, which were concomitant with that rats of MCAO at the same age displayed significant behavioral deficits. Bioinformatics analysis predicted the cell adhesion molecule 2 (Cadm2, mRNA) neurite outgrowth-associated protein is targeted by miR­125a. Overexpression of miR­125a reduced the level of Cadm2 expression in PC12 cell injury induced by free-serum. In contrast, inhibition of miR­125a using miR­125a inhibitors significantly resulted in higher levels of Cadm2 expression. In conclusion, miR­125a is involved in the behavioral disorder of animal models of MCAO by regulation of Cadm2.