Overexpression of miR-124 Protects Against Neurological Dysfunction Induced by Neonatal Hypoxic-Ischemic Brain Injury

MicroRNA-mediated regulation of nonsense-mediated mRNA decay factors: Insights into microRNA prediction tools and profiling techniques

Nonsense-mediated mRNA decay (NMD) stands out as a prominent RNA surveillance mechanism within eukaryotes, meticulously overseeing both RNA abundance and integrity by eliminating aberrant transcripts. These defective transcripts are discerned through the concerted efforts of translating ribosomes, eukaryotic release factors (eRFs), and trans-acting NMD factors, with Up-Frameshift 3 (UPF3) serving as a noteworthy component. Remarkably, in humans, UPF3 exists in two paralogous forms, UPF3A (UPF3) and UPF3B (UPF3X). Beyond its role in quality control, UPF3 wields significant influence over critical cellular processes, including neural development, synaptic plasticity, and axon guidance. However, the precise regulatory mechanisms governing UPF3 remain elusive. MicroRNAs (miRNAs) emerge as pivotal post-transcriptional gene regulators, exerting substantial impact on diverse pathological and physiological pathways. This comprehensive review encapsulates our current understanding of the intricate regulatory nexus between NMD and miRNAs, with particular emphasis on the essential role played by UPF3B in neurodevelopment. Additionally, we bring out the significance of the 3'-untranslated region (3'-UTR) as the molecular bridge connecting NMD and miRNA-mediated gene regulation. Furthermore, we provide an in-depth exploration of diverse computational tools tailored for the prediction of potential miRNA targets. To complement these computational approaches, we delineate experimental techniques designed to validate predicted miRNA-mRNA interactions, empowering readers with the knowledge necessary to select the most appropriate methodology for their specific research objectives.

MicroRNA-124 negatively regulates STAT3 to alleviate hypoxic-ischemic brain damage by inhibiting oxidative stress

MicroRNA-124 (miR-124) is implicated in various neurological diseases; however, its significance in hypoxic-ischaemic brain damage (HIBD) remains unclear. This study aimed to elucidate the underlying pathophysiological mechanisms of miR-124 in HIBD. In our study performed on oxygen-glucose deprivation followed by reperfusion (OGD)/R-induced primary cortical neurons, a substantial reduction in miR-124 was observed. Furthermore, the upregulation of miR-124 significantly mitigated oxidative stress, apoptosis, and mitochondrial impairment. We demonstrated that miR-124 interacts with the signal transducer and activator of transcription 3 (STAT3) to exert its biological function using the dual-luciferase reporter gene assay. As the duration of OGD increased, miR-124 exhibited a negative correlation with STAT3. STAT3 overexpression notably attenuated the protective effects of miR-124 mimics, while knockdown of STAT3 reversed the adverse effects of the miR-124 inhibitor. Subsequently, we conducted an HIBD model in rats. In vivo experiments, miR-124 overexpression attenuated cerebral infarction volume, cerebral edema, apoptosis, oxidative stress, and improved neurological function recovery in HIBD rats. In summary, the neuroprotective effects of the miR-124/STAT3 axis were confirmed in the HIBD model. MiR-124 may serve as a potential biomarker with significant therapeutic implications for HIBD.

MicroRNA-124 conducts neuroprotective effect via inhibiting AK4/ATF3 after subarachnoid hemorrhage

Spontaneous subarachnoid hemorrhage (SAH) accounts for approximately 5% of all cases of stroke. SAH is correlated with elevated rates of mortality and disability. Despite significant advancements in comprehending the pathogenesis and surgical management, efficacious clinical interventions remain restricted, and the prognosis is yet to be enhanced. MicroRNAs play a crucial role in various pathological processes in organisms. Revealing these regulatory processes is conducive to the development of new treatment methods. MicroRNA-124 is highly expressed in the nervous system and has significant research value for SAH. This study aims to explore the role of miR-124 in the early post-SAH period on neural function and verify whether it is involved in the pathological and physiological processes of SAH. In this study, we used methods such as comparing the expression levels of miR-124 in cerebrospinal fluid, establishing a rat SAH model, and a mouse embryonic primary neuron hemoglobin stimulation model to verify the downstream proteins of miR-124 in SAH. Through transfection techniques, we adjusted the expression of this small RNA in Vitro and in Vivo models using miR-124 inhibitor and mimic in the primary neuron hemoglobin stimulation model and rat SAH model, and observed the phenotype. Finally, by consulting the literature and verifying in Vivo and in Vitro methods, AK4 and downstream molecule ATF3 were identified as downstream targets of miR-124.

Astrocyte-derived extracellular vesicles inhibit the abnormal activation of immune function in neonatal mice with hypoxic-ischemic brain damage by carrying miR-124-3p

OBJECTIVE

Hypoxic-ischemic brain damage (HIBD) is among the leading causes of neonatal death worldwide. miR-124-3p can be utilized as a potential diagnostic and prognostic biomarker for perinatal asphyxia and HI encephalopathy in newborns. This study investigated the protective effect and mechanism of miR-124-3p in astrocyte-derived extracellular vesicles (ADEVs) in HIBD.

METHODS

    The neonatal mouse model of HIBD was established. Astrocytes were transfected with the miR-124-3p inhibitor, followed by isolation and identification of ADEVs (ADEVs + inhi miR). HIBD mice were injected with ADEVs or ADEVs + inhi miR through the lateral ventricle, and neurological function was evaluated based on the modified neurological severity score (mNSS). The infarct volume of mice and the morphological modifications of neurons were observed by TTC staining and hematoxylin-eosin staining. The contents of SOD, GSH-Px, CAT, and MDA in the hippocampus were measured. The neuronal apoptosis, the activation of MPO+ neutrophils, NK cells, and CD3+ cells in CA1 region of the hippocampus was determined by means of TUNEL staining and immunofluorescence.

RESULTS

ADEVs alleviated HIBD in neonatal mice. ADEVs could intrinsically protect mice from HIBD by reducing oxidative stress and apoptosis in hippocampal tissue. ADEVs inhibited the positive expression of MPO+ neutrophils, NK cells, and CD3+ cells in HIBD neonatal mice. ADEVs inhibited the hippocampal immune cells by delivering miR-124-3p in neonatal HIBD mice.

CONCLUSION

ADEVs can inhibit the abnormal activation of immune function in HIBD by delivering miR-124-3p, thereby eliciting a protective effect on brain damage in neonatal mice.

Constraint therapy promotes motor cortex remodeling and functional improvement by regulating c-Jun/miR-182-5p/Nogo - A signals in hemiplegic cerebral palsy mice

BACKGROUND

Our previous study has confirmed that constraint-induced movement therapy (CIMT) could promote neural remodeling in hemiplegic cerebral palsy (HCP) mice through Nogo-A/NgR/RhoA/ROCK signaling, however, the upstream mechanism was still unclear. Therefore, the present study aimed to further explore the mechanism of CIMT regulating the expression of Nogo-A in HCP mice.

METHOD

HCP mice were well established through ligating the left common carotid artery of 7-day-old pups and being placed in a hypoxic box which was filled with a mixture of 8% oxygen and 92% nitrogen. CIMT intervention was conducted by taping to fix the entire arm of the contralateral side (left) to force the mice to use the affected limb (right). Bioinformatics prediction and luciferase experiment were performed to confirm that miR-182-5p was targeted with Nogo-A. The beam test and grip test were applied to examine the behavioral performance under the intervention of c-Jun and CIMT. Also, immunofluorescence, Golgi staining, and transmission electron microscopy were conducted to show that the lenti-expression of c-Jun could increases the expression of myelin, and downregulates the expression of Nogo-A under the CIMT on HCP mice.

RESULT

(1) The beam walking test and grip test experiment results showed that compared with the control group, the HCP + nCIMT group's forelimb grasping ability and balance coordination ability were decreased (P < 0.05). (2) The results of Golgi staining, and transmission electron microscopy showed that the thickness of myelin sheath and the density of dendritic spines in the HCP + nCIMT group were lower than those in the control group (P < 0.05). Compared with the HCP + nCIMT group, the cerebral cortex myelin sheath thickness, dendrite spine density and nerve filament expression were increased in HCP + CIMT group (P < 0.05). (3) Immunofluorescence staining showed that the expression of Nogo-A in the cerebral cortex of the HCP + nCIMT group was higher than that of the HCP + CIMT group (P < 0.05). Compared with the HCP + CIMT group, the expression of Nogo-A in the HCP + LC + CIMT group was decreased and, in the HCP, + SC + CIMT group was significantly increased (P < 0.05). Compared with the HCP + nCIMT group, the expression of c-Jun in the control, HCP + CIMT, HCP + LC + nCIMT and HCP + LC + CIMT groups was significantly increased, and in the HCP + SC + CIMT was decreased (P < 0.05). (4) Real-time quantitative polymerase chain reaction (RT-qPCR) results showed that the expression level of miR-182-5p in the HCP + LC + CIMT group was more increased than that in the HCP + nCIMT group (P < 0.05). The expression level of miR-182-5p in the HCP + LC + CIMT group was higher than that in the HCP + LC + nCIMT group and the HCP + SC + CIMT group (P < 0.05).

CONCLUSION

These data identified that CIMT might stimulate the remodeling of neurons and myelin in the motor cortex by partially inhibiting the c-Jun/miR-182-5p/Nogo-A pathway, thereby facilitating the grasping performance and balance function of HCP mice.

Dexmedetomidine suppresses hippocampal astrocyte pyroptosis in cerebral hypoxic-ischemic neonatal rats by upregulating microRNA-148a-3p to inactivate the STAT/JMJD3 axis

OBJECTIVE

Dexmedetomidine (DEX), a selective α2-adrenoceptor agonist, is an anesthetic and sedative agent and has been reported to confer neuroprotective effects after cerebral hypoxic ischemia (CHI). This study was undertaken to elucidate the mechanisms by which microRNA (miR)-148a-3p is involved in the neuroprotective effect of DEX on hypoxic-ischemic brain damage in neonatal rats.

METHODS

Neonatal rats were exposed to CHI conditions, a miR-148a-3p inhibitor, and DEX. Hippocampal astrocytes were isolated to construct an oxygen-glucose deprivation (OGD) model. qRT-PCR and western blot were utilized to inspect miR-148a-3p, STAT1, STAT3, JMJD3, cleaved-Caspase-1, ASC, NLRP3, GSDMD, and GSDMD-N expression in rats and astrocytes. TUNEL staining was employed to measure astrocyte apoptosis rate, immunofluorescence to inspect cleaved-Caspase-1 and ASC levels, and ELISA to determine IL-1β and IL-18 expression. The target genes of miR-148a-3p were predicted using online software and verified by a dual-luciferase reporter gene assay.

RESULTS

A prominent increase in astrocyte apoptosis rate and the expression of pyroptosis- and inflammation-related factors were found in rats with CHI and OGD-treated astrocytes. DEX suppressed astrocyte apoptosis rate and decreased expression of pyroptosis- and inflammation-related factors. Knockdown of miR-148a-3p facilitated astrocyte pyroptosis, indicating that DEX exerted its protective effect by upregulating miR-148a-3p. miR-148a-3p negatively mediated STAT to inactivate JMJD3. Overexpression of STAT1 and STAT3 facilitated pyroptosis in astrocytes, which was negated by the overexpression of miR-148a-3p.

CONCLUSION

DEX inhibited hippocampal astrocyte pyroptosis by upregulating miR-148a-3p to inactivate the STAT/JMJD3 axis, thereby alleviating cerebral damage in neonatal rats with CHI.

MicroRNA therapeutic targets in neonatal hypoxic-ischemic brain injury: a narrative review

Neonatal hypoxic-ischemic brain injury (HIBI) is a devastating injury resulting from impaired blood flow and oxygen delivery to the brain at or around the time of birth. Despite the use of therapeutic hypothermia, more than one in four survivors suffer from major developmental disabilities-an indication of the critical need for more effective therapies. MicroRNAs (miRNA) have the potential to act as biomarkers and/or therapeutic targets in neonatal HIBI as a step toward improving outcomes in this high-risk population. This review summarizes the current literature around the use of cord blood and postnatal circulating blood miRNA expression for diagnosis or prognosis in human infants with hypoxic-ischemic encephalopathy, as well as animal studies assessing endogenous brain miRNA expression and potential for therapeutic targeting of miRNA expression for neuroprotection. Ultimately, the lack of knowledge regarding brain specificity of circulating miRNAs and the temporal variability in expression currently limit the use of miRNAs as biomarkers. However, given their broad effect profile, ease of administration, and small size allowing for effective blood-brain barrier crossing, miRNAs represent promising therapeutic targets for improving brain injury and reducing developmental impairments in neonates after HIBI. IMPACT: The high morbidity and mortality of neonatal hypoxic-ischemic brain injury (HIBI) despite current therapies demonstrates a need for developing more sensitive biomarkers and superior therapeutic options. MicroRNAs have been evaluated both as biomarkers and therapeutic options after neonatal HIBI. The limited knowledge regarding brain specificity of circulating microRNAs and temporal variability in expression currently limit the use of microRNAs as biomarkers. Future studies comparing the neuroprotective effects of modulating microRNA expression must consider temporal changes in the endogenous expression to determine appropriate timing of therapy, while also optimizing techniques for delivery.

Intracranial delivery of synthetic mRNA to suppress glioblastoma

Owing to messenger RNA's unique biological advantages, it has received increasing attention to be used as a therapeutic, known as mRNA-based gene therapy. It is critical to have an ideal strategy of mRNA gene therapy for glioma, which grows in a special environment. In the present study, we screened out a safe and efficient transfection reagent for intracranial delivery of synthetic mRNA in mouse brain. First, in order to analyze the effect of different transfection reagents on the intracranial delivery of mRNA, the synthetic luciferase mRNA was wrapped with two different transfection reagents and microinjected into the brain at the fixed point. The expression status of delivered mRNA was monitored by a small animal imaging system. The possible reagent-induced biological toxicity was evaluated by behavioral and blood biochemical measurements. Then, to test the therapeutic effect of our intracranial delivery mRNA model on glioma, synthetic modified tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mRNA was used as an example of therapeutic application. This model demonstrated that synthetic mRNA could be successfully delivered into the brain using commercially available transfection reagents, and TransIT-mRNA showed better results than in vivo-jetPEI kit. This model can be applied in precise targeting and personalized gene therapy of glioma.

Early Brain microRNA/mRNA Expression is Region-Specific After Neonatal Hypoxic-Ischemic Injury in a Mouse Model

Background: MicroRNAs (miRNAs) may be promising therapeutic targets for neonatal hypoxic-ischemic brain injury (HIBI) but targeting miRNA-based therapy will require more precise understanding of endogenous brain miRNA expression. Methods: Postnatal day 9 mouse pups underwent HIBI by unilateral carotid ligation + hypoxia or sham surgery. Next-generation miRNA sequencing and mRNA Neuroinflammation panels were performed on ipsilateral cortex, striatum/thalamus, and cerebellum of each group at 30 min after injury. Targeted canonical pathways were predicted by KEGG analysis. Results: Sixty-one unique miRNAs showed differential expression (DE) in at least one region; nine in more than one region, including miR-410-5p, -1264-3p, 1298-5p, -5,126, and -34b-3p. Forty-four mRNAs showed DE in at least one region; 16 in more than one region. MiRNAs showing DE primarily targeted metabolic pathways, while mRNAs targeted inflammatory and cell death pathways. Minimal miRNA-mRNA interactions were seen at 30 min after HIBI. Conclusion: This study identified miRNAs that deserve future study to assess their potential as therapeutic targets in neonatal HIBI. Additionally, the differences in miRNA expression between regions suggest that future studies assessing brain miRNA expression to guide therapy development should consider evaluating individual brain regions rather than whole brain to ensure the sensitivity needed for the development of targeted therapies.

Bone marrow mesenchymal stem cells-derived exosomal microRNA-124-3p attenuates hypoxic-ischemic brain damage through depressing tumor necrosis factor receptor associated factor 6 in newborn rats

Mesenchymal stem cells (MSCs)-derived exosomes (Exo) are beneficial in the use of brain damages. Restrictively, the mechanism of Exo expressing miR-124-3p in hypoxic-ischemic brain damage (HIBD) is not completely comprehended. Thereupon, this work was put forward to reveal the action of bone marrow MSCs-derived Exo (BMSCs-Exo) expressing miR-124-3p in the illness. BMSCs were isolated and transfected with miR-124-3p agomir. Then, BMSCs-Exo were extracted and identified. The newborn HIBD rats were injected with miR-124-3p-modified BMSCs-Exo or tumor necrosis factor receptor associated factor 6 (TRAF6)-related vectors. Next, neurological functions, neuron pathological and structural damages, oxidative stress and neuronal apoptosis were observed. miR-124-3p and TRAF6 expression was tested, along with their targeting relationship. miR-124-3p was down-regulated, and TRAF6 was up-regulated in newborn HIBD rats. miR-124-3p targeted TRAF6. BMSCs-Exo improved neurological functions, alleviated neuron pathological and structural damages, suppressed oxidative stress and reduced neuronal apoptosis in newborn HIBD rats, whereas BMSCs-Exo-mediated effects were enhanced by restoring miR-124-3p. Silencing TRAF6 attenuated HIBD in newborn rats, but overexpression of TRAF6 reversed the protective role of miR-124-3p-overexpressing BMSCs-Exo. This work makes it comprehensive that up-regulated exosomal miR-124-3p ameliorates HIBD in newborn rats by targeting TRAF6, which replenishes the potential agents for curing HIBD.

Neuroprotective effects of coenzyme Q10 in Parkinson's model via a novel Q10/miR-149-5p/MMPs pathway

Parkinson's disease (PD) is a complex neurodegenerative disease in which the understanding of the underlying molecular mechanisms can be constructive in the diagnosis and treatment. Matrix metalloproteinase (MMPs) elevation and damage to the blood-brain barrier (BBB) are critical mechanisms involved in the PD separation. Studies have revealed that changes in miR-149-5p and CoQ10 are associated with BBB damage, and CoQ10 can affect the levels of some miRs. Hence, in the present study, we aimed to evaluate CoQ10 and miR-149-5p mimic on miR-149-5p, MMPs and TH expression, and behavioral functions of the PD models. PD was induced by injection of 6-OHDA into the rats' Medial Forbrain Bundle (MFB). The behavioral tests, including the Rotation test, Rotarod test, and Open field test, have been directed two weeks after PD induction. Next, the MiR-149-5p mimic (miR-mimic) and CoQ10 have been administered to rats. The same behavioral tests have been evaluated two weeks after administration to investigate the effect of miR-149-5p mimic and CoQ10. The rats were followed extra four weeks, and the behavioral tests have performed again. Finally, the expression of MMPs and miR-149-5p genes was measured using RT-qPCR, and tyrosine hydroxylase (TH) was assessed through immunohistochemistry analysis. According to the obtained results, the level of miR-149-5p has decreased, followed by PD induction in rats. RT-qPCR analysis has represented upregulation and downregulation of miR-149-5p and MMP-2,9, respectively, after miR-mimic and CoQ10 treatment. The treated rats have also represented improved motor function and increased TH +  cells in the striatum according to the behavioral tests and immunohistochemistry assay. Taking together miR-149 and CoQ10 has shown to have an impressive potential to prevent damage to dopaminergic neurons caused by 6-OHDA injection through reducing MMP-2,9, increased TH expression, and improved motor function.

Peroxiredoxin 6 secreted by Schwann-like cells protects neuron against ischemic stroke in rats via PTEN/PI3K/AKT pathway

Schwann cells can promote the survival of damaged neurons and axon regeneration by secreting or releasing some proteins and factors which may provide effective strategies to the remedy for ischemic stroke. The models of middle cerebral artery occlusion and oxygen-glucose deprivation (OGD) were established. Peroxiredoxin 6 (PRDX6) was found in Schwann-like cell conditioned medium (SCLC-CM) by mass spectrometry. The rehabilitative performance of SCLC-CM on focal cerebral ischemia of rats and on OGD-induced PC12 cells were assessed. SCLC-CM significantly improved neurological recovery, reducing the infarct volume of rats after stroke. PRDX6 could significantly inhibit neuron apoptosis in the OGD injury by mediating oxidative stress and activating the PTEN/PI3K/AKT pathway. In conclusion, PRDX6 secreted by Schwann-like cell protects neuron against focal cerebral ischemia, SCLC-CM might be a new effective early intervention for ischemic stroke.

MiR-363-3p attenuates neonatal hypoxic-ischemia encephalopathy by targeting DUSP5

Neonatal hypoxic-ischemia encephalopathy (HIE) refers to hypoxic-ischemic brain damage caused by perinatal asphyxia. Increasing evidence has revealed the crucial roles of microRNAs (miRNAs) in neonatal HIE. In the current research, we aimed to explore the biological role of miR-363-3p in neonatal HIE. For this purpose, we established in vitro models of PC-12 and SH-SY5Y cells subjected to oxygen-glucose deprivation and reperfusion (OGD/R) and an in vivo rat model subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) treatment. First, using H&E staining, TTC staining, and western blot analysis, we observed that DUSP5 knockdown suppressed HIE in vivo. Then, by performing flow cytometric analysis, western blotting, RT-qPCR, and MTT assays, we observed that DUSP5 silencing suppressed OGD/R-induced cell injury in vitro. Subsequently, we explored the potential regulatory mechanism of DUSP5 in OGD/R-treated cells with luciferase reporter assays and RT-qPCR analysis. The results demonstrated that DUSP5 was targeted by miR-363-3p. Next, functional assays, including flow cytometric analysis, MTT assays, western blotting and RT-qPCR, were conducted to explore the biological functions of miR-363-3p in SH-SY5Y and PC-12 cells. Our data showed that miR-363-3p overexpression suppressed OGD/R-induced cell injury. Finally, the results from rescue experiments showed that enhanced DUSP5 expression counteracted the effect of miR-363-3p overexpression. In conclusion, our data suggested that miR-363-3p attenuates neonatal HIE by targeting DUSP5.

Epigenetic upregulation of ssc-miR-124a following treatment with Clostridium perfringens beta2-toxin attenuates both apoptosis and inflammation in intestinal porcine epithelial cells

Clostridium perfringens (C. perfringens) is a globally recognized zoonotic pathogen. It has been reported that the beta2-toxin produced by C. perfringens can cause a variety of gastrointestinal diseases and even systemic inflammation. MicroRNA-124a (miR-124a) has been reported to play important roles in the host response to pathogenic infection. Although C. perfringens beta2-toxin induced injury in intestinal porcine epithelial (IPEC-J2) cells has been established, the underlying molecular mechanism is not completely unraveled. Here we show that a significant upregulation of ssc-miR-124a in IPEC-J2 cells after beta2-toxin stimulation was associated with the MiR-124A-1 and MiR-124A-2 gene promoter demethylation status. Importantly, overexpression of ssc-miR-124a significantly increased cell proliferation and decreased apoptosis and cytotoxicity in beta2-toxin treated IPEC-J2 cells. Transfection of IPEC-J2 cells with ssc-miR-124a mimic suppressed beta2-toxin induced inflammation. On the contrary, ssc-miR-124a inhibitor promoted aggravation of cell apoptosis and excessive damage. Furthermore, rho-associated coiled-coil-containing protein kinase 1 (ROCK1) was identified as the direct target gene of ssc-miR-124a in IPEC-J2 cells and its siRNA transfection reversed the promotion of apoptosis and aggravation of cellular damage induced by ssc-miR-124a inhibitor. Overall, we speculated that the miR-124A-1/2 gene was epigenetically regulated in IPEC-J2 cells after beta2-toxin treatment. Upregulation of ssc-miR-124a may restrain ROCK1, and attenuate apoptosis and inflammation induced by beta2-toxin that prevent IPEC-J2 cells from severe damages. We discover a new molecular mechanism by which IPEC-J2 cells counteract beta2-toxin-induced damage through the ssc-miR-124a/ROCK1 axis partially.

The neuroprotective effect of MicroRNA-149-5p and coenzymeQ10 by reducing levels of inflammatory cytokines and metalloproteinases following focal brain ischemia in rats

The increase in some factors following cerebral ischemia, especially Matrix metalloproteinase (MMPs) and inflammatory factors lead to blood-brain barrier (BBB) damages, edema and neuronal death. Previous studies have shown that these molecules are miRNA-149-5p (miR-149) and Coenzyme (Co) Q10 targets. Therefore, in this study, the effect of mimic of miRNA-149-5p (mimic miR) and CoQ10 on the expression of metalloproteinase 1 and 2 and inflammatory cytokines following injury caused by cerebral ischemia is investigated. Cerebral ischemia was modeled by Middle Cerebral Artery Occlusion (MCAO). Male Wistar rats were randomly divided into 6 groups: sham (without surgery and treatment), control (MCAO), negative control (NC): MCAO + scrambled miR, vehicle: MCAO + Ethanole, first treatment: MCAO + mimic miR, second treatment: MCAO + Q10. Each group was divided into 6 subgroups to evaluate neurological defects, the volume of tissue damage using 2,3,5-triphenyl tetrazolium chloride (TTC) staining, blood-brain barrier permeability using cerebral Evans Blue (EB) staining, edema by measuring the percentage of brain water, MMP-2,9 mRNA and miR-149-5p levels using Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and the levels of IL-6 and TNF-α proteins using ELISA. The data obtained from this study showed that the use of mimic miR and Q10 increased the level of miR-149, decreased the extent of neurological defects and tissue damage, increased BBB integrity, decreased brain water percentage and also decreased the level of inflammatory cytokines and MMPs. It seems that the use mimic of miRNA-149-5p and Q10 can have a protective effect on the brain by reducing MMPs and inflammatory factors following cerebral ischemia and this could lead to a new treatment strategy to reduce the complications of cerebral ischemia.

MiR-410-3p overexpression ameliorates neurological deficits in rats with hypoxic-ischemic brain damage

Neonatal hypoxic-ischemic encephalopathy (HIE) is major cause of neonatal death or long-term neurodevelopmental disabilities, which becomes a major practical problem currently in clinic. Whereas, its pathophysiology and underlying molecular mechanism is not clear. MicroRNAs are involved in the normal growth and development of neuronal cells. Herein, the objective of this research was to examine the roles of miR-410-3p in neurological deficits, neuronal injury and neuron apoptosis after hypoxic-ischemic and to explore its associated mechanisms. We established the hypoxic-ischemic brain damage (HIBD) model and oxygen glucose deprivation (OGD) model. Zea-longa score and TTC staining were used to detect the acute cerebral dysfunction after HIBD. QPCR verification exhibited notable downregulation of miR-410-3p expression at 24 h in rats after HIBD as well as that in PC12, SY5Y cells and primary cortical neurons post OGD. To further determine the function of miR-410-3p, lentivirus-mediated overexpression virus was applied in vivo and in vitro. Behavioral tests, including Morris water maze, open field test, Y maze test, neurological severity score and rotating rod test, were performed to evaluate long-term behavioral changes of rats at 1 month post HIBD. The results showed that the number of cells together with the axonal length were reduced post OGD. While the increase of cells number and the axonal length was measured after upregulating miR-410-3p. Meanwhile, miR-410-3p overexpression inhibited neuron apoptosis and enhanced neuronal survival. In addition, long-term motor and cognitive functions were remarkably recovered in HIBD rats with miR-410-3p overexpression. Together, miR-410-3p exerts a critical role in protecting neuronal growth as well as promoting motor and cognitive function recovery in neonatal rats subjected to HIBD. The current study therefore provides critical insights to develop the activator of miR-410-3p for the clinical treatment of HIBD in future clinic trial.