The role of microRNA in neuronal inflammation and survival in the post ischemic brain: a review

LncRNA SNHG15 regulates autophagy and prevents cerebral ischaemia-reperfusion injury through mediating miR-153-3p/ATG5 axis

Ischaemic stroke is a common cerebrovascular disease. Long non-coding RNA (lncRNA) of small nucleolar RNA host gene (SNHG15) has been supposedly performed a regulatory role in many diseases. Nonetheless, the function of SNHG15 in cerebral ischaemia-reperfusion injury has not been clarified. The OGD/R of Neuro2A cells simulated the ischaemic and reperfused states of the brain. Neuro2a cell line with stable transfection of plasmid with silent expression of SNHG15 was constructed. Neuro2a cell lines transfected with miR-153-3p mimic (miR-153-3p-mimics) and miR-153-3p inhibitor (miR-153-3p-inhibition) were constructed. Expression of SNHG15, mi R-200a, FOXO3 and ATG7 in mouse brain tissue and N2a cells was identified by qRT-PCR. Western blot (WB) analysis of mouse brain tissue and Neuro2a cells revealed the presence of the proteins ATG5, Cle-caspase-3, Bax, Bcl-2, LC3 II/I and P62 (WB). The representation and distribution of LC3B were observed by immunofluorescence. The death of cells was measured using a technique called flow cytometry (FACS). SNHG15 was highly expressed in cerebral ischaemia-reperfusion injury model. Down-regulation of SNHG15 lead to lower apoptosis rate and decreased autophagy. Dual luciferase assay and co-immunoprecipitation (CoIP) found lncRNA SNHG15/miR-153-3p/ATG5. Compared to cells transfected with NC suppression, cells transfected with miR-153-3p-inhibition had substantially greater overexpression of LC 3 II/I, ATG5, cle-Caspase-3, and Bax, as determined by a recovery experiment, the apoptosis rate was elevated, yet both P62 and Bcl-2 were significantly lower and LC3+ puncta per cells were significantly increased. Co-transfection of miR-153-3p-inhibition and sh-SNHG15 could reverse these results. LncRNA SNHG15 regulated autophagy and prevented cerebral ischaemia-reperfusion injury through mediating the miR-153-3p/ATG5 axis.

Neuroprotective effect of wild lowbush blueberry (Vaccinium angustifolium) on global cerebral ischemia/reperfusion injury in rats: Downregulation of iNOS/TNF-α and upregulation of miR-146a/miR-21 expression

This study aims to investigate the neuroprotective effect of wild lowbush blueberry on CIRI in rats. Accordingly, CIRI and reperfusion were induced in rats for 60 min and 24 h, respectively. Then, the mechanisms of the neuroprotective effects of BBE were investigated in the injury through evaluating miR-146a, miR-21, and their targets in a CIRI rat model. After that, the BBE (30, 60, and 120 mg/kg b.wt) was intraperitoneally injected for 14 days, then CIRI was induced by BCCAO for 60 min for ischemic stroke and reperfusion for 24 h. Several parameters including the oxidative stress levels in the hippocampus and serum were measured 24 h after the CIRI. The findings showed that the BBE significantly decreased the levels of malondialdehyde (MDA) and nitric oxide (NO) and increased ferric ion reducing antioxidant power (FRAP) levels in the hippocampus and serum following the stroke. The BBE also maximized the miR-146a and miR-21 expressions and moderated iNOS and TNF-α expressions in the hippocampus. Likewise, the BBE enlarged the CA1 and CA3 domains of the post-stroke pyramidal cell layers of the hippocampus. Overall, the results revealed that BBE had potent neuroprotective efficacy against CIRI via the effective modulation of neuroinflammatory cascades and protected neurons against ischemic death.

Efficient roles of miR-146a in cellular and molecular mechanisms of neuroinflammatory disorders: An effectual review in neuroimmunology

Known as one of the most sophisticated systems of the human body, the nervous system consists of neural cells and controls all parts of the body. It is closely related to the immune system. The effects of inflammation and immune reactions have been observed in the pathogenesis of some neurological disorders. Defined as the gene expression regulators, miRNAs participate in cellular processes. miR-146a is a mediator in the neuroimmune system, leaving substantial effects on the homeostasis of immune and brain cells, neuronal identities acquisition, and immune responses regulation in the nervous system. Its positive efficiency has been proven in modulating inflammatory reactions, hemorrhagic complications, and pain. Moreover, the miR-146a targets play a key role in the pathogenesis of these illnesses. Based on the performance of its targets, miR-146a can have various effects on the disease progress. The abnormal expression/function of miR-146a has been reported in neuroinflammatory disorders. There is research evidence that this molecule qualifies as a desirable biomarker for some disorders and can even be a therapeutic target. This study aims to provide a meticulous review regarding the roles of miR-146a in the pathogenesis and progression of several neuroinflammatory disorders such as multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease, temporal lobe epilepsy, ischemic stroke, etc. The study also considers its eligibility for use as an ideal biomarker and therapeutic target in these diseases. The awareness of these mechanisms can facilitate the disease management/treatment, lead to patients' amelioration, improve the quality of life, and mitigate the risk of death.

Astrocyte-derived exosomes carry microRNA-17-5p to protect neonatal rats from hypoxic-ischemic brain damage via inhibiting BNIP-2 expression

Exosomes play critical roles in neurogenesis. This study aims to explore the mechanism of astrocyte-derived exosomes in neonatal rats with hypoxic-ischemic brain damage (HIBD). Astrocytes were collected and astrocyte-derived exosomes were isolated and identified. Neonatal rats were pre-treated with exosomes and then subjected to HIBD induction. Then the neurobehaviors, neuronal apoptosis, inflammation and oxidative stress in rat brain were measured. Differentially expressed microRNAs (miRNAs) in rat brain before and after HI procedure were analyzed. H19-7 cells were subjected to oxygen and glucose deprivation (OGD) for in vitro studies. Target relation between miR-17-5p and BNIP2 was identified. Gain- and loss-of functions of miR-17-5p and BNIP2 were conducted to identify their roles in viability, apoptosis, oxidative stress and inflammation of OGD-treated cells. Collectively, astrocyte-derived exosomes improved neurobehaviors, and reduced cerebral infarction, neuronal apoptosis, oxidative and inflammation in vivo and in vitro. The exosomes carried miR-17-5p bound to BNIP2 and negatively regulated BNIP2 expression in OGD-treated cells. Over-expression of miR-17-5p increased viability, and decreased OGD-induced apoptosis, oxidative stress and inflammation of H19-7 cells, which were reversed by over-expression of BNIP2. Taken together, the study suggested that astrocyte-derived exosomes could carry miR-17-5p to protect neonatal rats from HIBD via inhibiting BNIP-2 expression.

miR-22 protect PC12 from ischemia/reperfusion-induced injury by targeting p53 upregulated modulator of apoptosis (PUMA)

MicroRNAs have been implicated as critical regulatory molecules in many cerebrovascular diseases. Recent studies demonstrated miR-22 might provide a potential neuroprotective effect. However, the neuroprotective effect of miR-22 in ischemia/reperfusion (I/R) injury has not been thoroughly elucidated. In this study, the PC12 cells were subjected to 4 h oxygen and glucose deprivation (I) and 24 h reoxygenation (R). The PC12 cells were pre-transfected with miR-22 or anti-miR-22 or siRNA-mediated downregulation of p53-upregulated-modulator-of-apoptosis (PUMA)(PUMA siRNA) or their controls at 24 h prior to exposure to I/R. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot were employed to analyze mRNA and protein expression. PI and Annexin V assays and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assay were used to quantify the rate of apoptosis. We found that miR-22 expression was significantly downregulated in the PC12 cells subjected to I/R. Loss of function of miR-22 increased PC12 apoptosis after I/R, and overexpression of miR-22 decreases PC12 apoptosis after I/R. PUMA protein was upregulated in the I/R group as compared with the sham group. The increased PUMA protein expression and apoptosis induced by I/R was reversed by transfection with PUMA siRNA. We concluded that I/R enhanced apoptosis and PUMA expression in PC12 cells via downregulation of miR-22. Enhanced miR-22 expression reversed both PUMA expression and apoptosis induced by I/R in PC12 cells. miR-22/PUMA axis has important implications for their clinical applications.

MicroRNA-9 mediated the protective effect of ferulic acid on hypoxic-ischemic brain damage in neonatal rats

Neonatal hypoxic-ischemic brain damage (HIBD) is prone to cognitive and memory impairments, and there is no effective clinical treatment until now. Ferulic acid (FA) is found within members of the genus Angelica, reportedly shows protective effects on neuronal damage. However, the protective effects of FA on HIBD remains unclear. In this study, using the Morris water maze task, we herein found that the impairment of spatial memory formation in adult rats exposed to HIBD was significantly reversed by FA treatment and the administration of LNA-miR-9. The expression of miRNA-9 was detected by RT-PCR analyses, and the results shown that miRNA-9 was significantly increased in the hippocampus of neonatal rats following HIBD and in the PC12 cells following hypoxic-ischemic injury, while FA and LNA-miR-9 both inhibited the expression of miRNA-9, suggesting that the therapeutic effect of FA was mainly attributed to the inhibition of miRNA-9 expression. Indeed, the silencing of miR-9 by LNA-miR-9 or FA similarly attenuated neuronal damage and cerebral atrophy in the rat hippocampus after HIBD, which was consistent with the restored expression levels of brain-derived neurotrophic factor (BDNF). Therefore, our findings indicate that FA treatment may protect against neuronal death through the inhibition of miRNA-9 induction in the rat hippocampus following hypoxic-ischemic damage.

Dynamic Changes in miR-126 Expression in the Hippocampus and Penumbra Following Experimental Transient Global and Focal Cerebral Ischemia-Reperfusion

miR-126 which is considered one of the most important miRNAs for maintaining vascular integrity, plays an important role in neuroprotection after cerebral ischemia-reperfusion (I-R). Moreover, vascular endothelial growth factor A (VEGFA), sprouty-related EVH1 domain-containing protein 1 (SPRED1), and Raf-1 are also involved in physiological processes of vascular endothelial cells (ECs). This study investigated how miR-126 changes with reperfusion time in different brain tissues after global cerebral ischemia and focal cerebral ischemia and examined the underlying mechanism miR-126 involving VEGFA, SPRED1, and Raf-1 after I-R. The results indicated decreases in the levels of miR-126-3p and miR-126-5p expression in mice and gerbils after I-R, consistent with the results after oxygen and glucose deprivation and reperfusion (OGD/R) in PC12 cells. Glial cells were activated as neuronal damage gradually increased after I-R. Inhibition of miR-126-3p exacerbated the OGD/R-induced cell death and reduced cell viability. After miR-126-3p inhibition, the levels of SPRED1 and VEGFA expression were increased, and p-Raf-1 expression was decreased after OGD/R. Moreover, based on the intervention of miR-126-3p inhibition, we found that the expression of p-Raf-1 was significantly increased after the intervention of siSPRED1, while it was not statistically significant after intervention of siVEGFA. The reduction of miR-126 expression after global and focal cerebral ischemia exacerbated neuronal death, which was closely related to increasing the SPRED1 activation and inhibiting the Raf-1 expression.

Ischemia/Reperfusion Injury Revisited: An Overview of the Latest Pharmacological Strategies

Ischemia/reperfusion injury (IRI) permeates a variety of diseases and is a ubiquitous concern in every transplantation proceeding, from whole organs to modest grafts. Given its significance, efforts to evade the damaging effects of both ischemia and reperfusion are abundant in the literature and they consist of several strategies, such as applying pre-ischemic conditioning protocols, improving protection from preservation solutions, thus providing extended cold ischemia time and so on. In this review, we describe many of the latest pharmacological approaches that have been proven effective against IRI, while also revisiting well-established concepts and presenting recent pathophysiological findings in this ever-expanding field. A plethora of promising protocols has emerged in the last few years. They have been showing exciting results regarding protection against IRI by employing drugs that engage several strategies, such as modulating cell-surviving pathways, evading oxidative damage, physically protecting cell membrane integrity, and enhancing cell energetics.

Protective effect of glycyrrhizic acid on cerebral ischemia/reperfusion injury via inhibiting HMGB1-mediated TLR4/NF-κB pathway

Cerebral ischemia is caused by various disorders, such as stroke, myocardial infarction, or peripheral vascular disease. The purpose of this paper was to investigate the effects of glycyrrhizic acid (GA) on cerebral ischemia/reperfusion (I/R) injury. Middle cerebral artery occlusion was established to evaluate the effects of GA on cerebral ischemia. In this study, our results showed that GA could dramatically decrease cerebral edema, reduce the neurological deficits, and smaller brain infarct volume was found in the GA treatment group. In serum and brain tissue, GA also increased superoxide dismutase activity. In addition, in serum and brain tissue, GA also dramatically inhibited the secretion of inflammatory cytokines, including interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α. Moreover, GA inhibited the expressions of high-mobility group protein box-1 (HMGB1)-mediated TLR4/NF-κB pathway. Our data determined that GA may provide protective effect on the I/R-induced cerebral ischemia disease.

Artificial Hibernation by Phenothiazines: A Potential Neuroprotective Therapy Against Cerebral Inflammation in Stroke

Background:

The inflammatory response to acute cerebral ischemia is a major factor in stroke pathobiology and patient outcome. In the clinical setting, no effective pharmacologic treatments are currently available. Phenothiazine drugs, such as chlorpromazine and promethazine, (C+P) have been widely studied because of their ability to induce neuroprotection through artificial hibernation after stroke. The present study determined their effect on the inflammatory response.

Methods:

Sprague-Dawley rats were divided into 4 groups: (1) sham, (2) stroke, (3) stroke treated by C+P without temperature control and (4) stroke treated by C+P with temperature control (n=8 per group). To assess the neuroprotective effect of C+P, brain damage was measured using infarct volume and neurological deficits. The expression of inflammatory response molecules tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and nuclear factor kappa light chain enhancer of activated B cells (NF-κB) was determined by real-time PCR and Western blotting

Results:

TNF-α, IL-1β, ICAM-1, VCAM-1, and NF-κB mRNA and protein expressions were upregulated, and brain damage and neurological deficits were increased after stroke. These markers of cerebral injury were significantly reduced following C+P administration under drug-induced hypothermia, while C+P administration under normal body temperature reduced them by a lesser degree.

Conclusion:

This study showed an inhibitory effect of C+P on brain inflammation, which may be partially dependent on drug-induced hibernation, as well as other mechanisms of action by these drugs. These findings further suggest the great potential of C+P in the clinical treatment of ischemic stroke.

Whole blood microRNA expression associated with stroke: Results from the Framingham Heart Study

Emerging evidence suggests microRNAs (miRNAs) may play an important role in explaining variation in stroke risk and recovery in humans, yet there are still few longitudinal studies examining the association between whole blood miRNAs and stroke. Accounting for multiple testing and adjusting for potentially confounding technical and clinical variables, here we show that whole blood miR-574-3p expression was significantly lower in participants with chronic stroke compared to non-cases. To explore the functional relevance of our findings, we analyzed miRNA-mRNA whole blood co-expression, pathway enrichment, and brain tissue gene expression. Results suggest miR-574-3p is involved in neurometabolic and chronic neuronal injury response pathways, including brain gene expression of DBNDD2 and ELOVL1. These results suggest miR-574-3p plays a role in regulating chronic brain and systemic cellular response to stroke and thus may implicate miR-574-3p as a partial mediator of long-term stroke outcomes.

Rabies virus glycoprotein (RVG29)-linked microRNA-124-loaded polymeric nanoparticles inhibit neuroinflammation in a Parkinson's disease model

In the present study, we have prepared microRNA(miR)-124-loaded Rabies virus glycoprotein (RVG)29 surface-conjugated polymeric nanoparticles (NPs) to improve neuroinflammation in Parkinson's disease (PD). We hypothesize that an increase in the intracellular concentration of miR-124 will result in a better prognosis for Parkinson's disease. Minimal toxicity for the RVG29 NPs was observed at concentrations <100 µg/mL, while the cell viability of cells treated with blank NPs at concentrations of 200 µg/mL markedly decreased, indicating the safety of the carrier system. Results showed that mRNA levels of inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha (TNF-α), and interleukin (IL)-6, significantly increased upon lipopolysaccharide (LPS) administration. However, the mRNA levels of these cytokines reflected those of the miR-NPs-treated control group, indicating the influence of miR-124 exposure. After transfection with miR-NPs, levels of pro-inflammatory cytokines and neuroprotective molecules were reduced and increased, respectively. Administration of LPS significantly increased the levels of mitogen activated protein kinase kinase kinase (MEKK)3 and P-P65 levels, while transfection with miR-NPs significantly reduced the expression of both MEKK3 and P-P65, reflecting that of the control. This research has revealed that miR-124 could target both the MEKK3 and nuclear factor kappa light chain enhancer of activated B cell (NF-Kb) pathways, while also reducing inflammatory cytokine levels. In addition, a 3-fold decrease in apoptosis was observed in miR-NP transfected cells. The exogenous delivery of miR-NPs significantly downregulated MEKK3 expression in animal studies, as outlined by immunohistochemical staining (IHC). Overall, miR-NPs have the potential to inhibit pro-inflammatory signaling and enhance neuroprotection in PD.

Down-regulation of lncRNA GAS5 attenuates neuronal cell injury through regulating miR-9/FOXO3 axis in cerebral ischemic stroke

Cerebral ischemic stroke is a leading cause of neurological disability worldwide. Previous study reported that long noncoding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5) was highly expressed in ischemic stroke. However, the mechanism underlying GAS5 in an inflammatory injury during an ischemic stroke remains poorly understood. An in vivo mouse model of middle cerebral artery occlusion (MCAO) and an in vitro cell model of oxygen-glucose deprivation (OGD) were established to induce cerebral ischemic stroke condition. The expressions of GAS5, microRNA-9 (miR-9) and forkhead box O3 (FOXO3) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot analysis, respectively. The neurological injury in vivo was investigated by neurological score and TTC staining. Cell apoptosis and inflammatory injury were analyzed by western blot, flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively. The interaction between miR-9 and GAS5 or FOXO3 was explored by luciferase activity, RNA pull-down and RNA immunoprecipitation (RIP) assays. GAS5 expression was enhanced in the cerebral ischemic stroke model. Knockdown of GAS5 attenuated the cerebral infarct, neurological injury, apoptosis and inflammatory injury in the mouse MCAO model. miR-9 was bound to GAS5 and its overexpression inhibited cell apoptosis and inflammatory response in OGD-treated bEnd.3 cells, which was attenuated by GAS5. FOXO3 was a target of miR-9 and its restoration reversed the miR-9-mediated suppression of apoptosis and inflammation. Moreover, GAS5 promoted FOXO3 expression by competitively sponging miR-9. GAS5 knockdown alleviated neuronal cell injury by regulating miR-9/FOXO3, providing a new theoretical foundation for cerebral ischemic stroke.

Cerebral ischemic stroke is a leading cause of neurological disability worldwide.

Epigenetic regulation of inflammation in stroke

Despite extensive research, treatments for clinical stroke are still limited only to the administration of tissue plasminogen activator and the recent introduction of mechanical thrombectomy, which can be used in only a limited proportion of patients due to time constraints. A plethora of inflammatory events occur during stroke, arising in part due to the body's immune response to brain injury. Neuroinflammation contributes significantly to neuronal cell death and the development of functional impairment and death in stroke patients. Therefore, elucidating the molecular and cellular mechanisms underlying inflammatory damage following stroke injury will be essential for the development of useful therapies. Research findings increasingly point to the likelihood that epigenetic mechanisms play a role in the pathophysiology of stroke. Epigenetics involves the differential regulation of gene expression, including those involved in brain inflammation and remodelling after stroke. Hence, it is conceivable that epigenetic mechanisms may contribute to differential interindividual vulnerability and injury responses to cerebral ischaemia. In this review, we summarize recent findings on the emerging role of epigenetics in the regulation of neuroinflammation in stroke. We also discuss potential epigenetic targets that may be assessed for the development of stroke therapies.

Altered Expression of miR-181a-5p and miR-23a-3p Is Associated With Obesity and TNFα-Induced Insulin Resistance

CONTEXT

The proinflammatory cytokine TNFα is a key player in insulin resistance (IR). The role of miRNAs in inflammation associated with IR is poorly understood.

OBJECTIVE

To investigate miR-181a-5p and miR-23a-3p expression profiles in obesity and to study their role in TNFα-induced IR in adipocytes.

DESIGN

Two separate cohorts were used. Cohort 1 was used in adipose tissue (AT) expression studies and included 28 subjects with body mass index (BMI) <30 kg/m2 and 30 with BMI ≥30 kg/m2. Cohort 2 was used in circulating serum miRNA studies and included 101 subjects with 4 years of follow-up (48 case subjects and 53 control subjects). miR-181a-5p and miR-23a-3p expression was assessed in subcutaneous and visceral AT. Functional analysis was performed in adipocytes, using miRNA mimics and inhibitors. Key molecules of the insulin pathway, AKT, PTEN, AS160, and S6K, were analyzed.

RESULTS

Expression of miR-181a-5p and miR-23a-3p was reduced in adipose tissue from obese and diabetic subjects and was inversely correlated to adiposity and homeostasis model assessment of IR index. Overexpression of miR-181a-5p and miR-23a-3p in adipocytes upregulated insulin-stimulated AKT activation and reduced TNFα-induced IR, regulating PTEN and S6K expression. Serum levels of miR-181a-5p were reduced in case vs control subjects at baseline, suggesting a prognostic value. Variable importance in projection scores revealed miR-181a-5p had more effect on the model than insulin or glucose at 120 minutes.

CONCLUSION

miR-181a-5p and miR-23a-3p may prevent TNFα-induced IR in adipocytes through modulation of PTEN and S6K expression.

MicroRNA-124 regulates the expression of MEKK3 in the inflammatory pathogenesis of Parkinson's disease

Background

Parkinson’s disease (PD) is the most prevalent neurodegenerative disorder that is characterised by selective loss of midbrain dopaminergic (DA) neurons. Chronic inflammation of the central nervous system is mediated by microglial cells and plays a critical role in the pathological progression of PD. Brain-specific microRNA-124 (miR-124) expression is significantly downregulated in lipopolysaccharide (LPS)-treated BV2 cells and in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD. However, whether abnormal miR-124 expression could regulate the activation of microglia remains poorly understood.

Methods

BV2 cells were activated by exposure to LPS, and the expression levels of miR-124, mitogen-activated protein kinase kinase kinase 3 (MEKK3), and the nuclear factor of kappaB (NF-κB) p-p65 were analysed. Over-expression and knockdown studies of miR-124 were performed to observe the effects on MEKK3/NF-κB signalling pathways, and the induction of pro-inflammatory and neurotoxic factors was assessed. In addition, a luciferase reporter assay was conducted to confirm whether MEKK3 is a direct target of miR-124. Meanwhile, production of miR-124, MEKK3, and p-p65; midbrain DA neuronal death; or activation of microglia were analysed when treated with or without miR-124 in the MPTP-induced model of PD.

Results

We found that the knockdown of MEKK3 could inhibit the activation of microglia by regulating NF-κB expression. Over-expression of miR-124 could effectively attenuate the LPS-induced expression of pro-inflammatory cytokines and promote the secretion of neuroprotective factors. We also first identified a unique role of miR-124 in mediating the microglial inflammatory response by targeting MEKK3/NF-κB signalling pathways. In the microglial culture supernatant (MCS) transfer model, over-expression of the miR-124 or knockdown of MEKK3 in BV2 cells prevented SH-SY5Y from apoptosis and death. Moreover, MEKK3 and p-p65 were abundantly expressed in the midbrain. Furthermore, their expression levels increased and microglial activation was observed in the MPTP-induced model of PD. In addition, exogenous delivery of miR-124 could suppress MEKK3 and p-p65 expression and attenuate the activation of microglia in the substantia nigra pars compacta of MPTP-treated mice. miR-124 also could prevent MPTP-dependent apoptotic midbrain DA cell death in a MPTP-induced PD model.

Conclusions

Taken together, our data suggest that miR-124 can inhibit neuroinflammation in the development of PD by regulating the MEKK3/NF-κB signalling pathways and implicate miR-124 as a potential therapeutic target for regulating the inflammatory response in PD.