LncRNA-Meg3 promotes Nlrp3-mediated microglial inflammation by targeting miR-7a-5p

Novel insights into non-coding RNAs and their role in hydrocephalus

A large body of evidence has highlighted the role of non-coding RNAs in neurodevelopment and neuroinflammation. This evidence has led to increasing speculation that non-coding RNAs may be involved in the pathophysiological mechanisms underlying hydrocephalus, one of the most common neurological conditions worldwide. In this review, we first outline the basic concepts and incidence of hydrocephalus along with the limitations of existing treatments for this condition. Then, we outline the definition, classification, and biological role of non-coding RNAs. Subsequently, we analyze the roles of non-coding RNAs in the formation of hydrocephalus in detail. Specifically, we have focused on the potential significance of non-coding RNAs in the pathophysiology of hydrocephalus, including glymphatic pathways, neuroinflammatory processes, and neurological dysplasia, on the basis of the existing evidence. Lastly, we review the potential of non-coding RNAs as biomarkers of hydrocephalus and for the creation of innovative treatments.

LncRNA MEG3 promotes pyroptosis via miR-145-5p/TLR4/NLRP3 axis and aggravates cerebral ischemia-reperfusion injury

Long noncoding RNA (lncRNA) MEG3 has been considered as a novel target for alleviating the brain tissue damage during cerebral ischemia-reperfusion injury (CIRI). Numerous studies have reported that pyroptosis is involved in the pathogenesis of CIRI. This study focused on whether MEG3 modulates CIRI via pyroptosis and its underlying mechanism. The middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model and the oxygen glucose deprivation/reoxygenation (OGD/R) cell model were established. si-MEG3 and miR-145-5p inhibitor were transfected to inhibit MEG3 and miR-145-5p, respectively. As a TLR4 inhibitor, Resatorvid inhibits the TLR4 signaling pathway. TTC and TUNEL staining were used for infarction volume and cell death detection. The differential expression of MGE3, miR-145-5p, TLR4, NLRP3, Caspase-1, IL-1β, and IL-18 was determined using real-time PCR and western blot. The interaction between MEG3 and miR-145-5p, as well as between miR-145-5p and TLR4 was confirmed by the dual-luciferase reporter assay. This study confirmed that the elevated expression of MEG3 during CIRI, and it contributes to pyroptosis by regulating miR-145-5p/TLR4 axis. The knockdown of MEG3 reduced the expression of TLR4, NLRP3, Caspase-1, IL-1β, and IL-18, thereby preventing pyroptosis. Inhibition of miR-145-5p reversed the effect of MEG3 knockdown and promoted pyroptosis. Resatorvid, the inhibitor of TLR4, counteracted the effect of miR-145-5p inhibitor and suppressed pyroptosis. Our findings reveal that MEG3 promotes pyroptosis via miR-145-5p/TLR4/NLRP3 axis and aggravates CIRI, suggesting a potential therapeutic target for ischemic stroke.

LncRNA MEG3 exacerbates diabetic cardiomyopathy via activating pyroptosis signaling pathway

Background: Diabetic cardiomyopathy (DCM) is a prevalent complication observed in diabetic patients. The long non-coding RNA maternally expressed gene 3 (lncMEG3) has been found to be intricately associated with myocardial infarction and heart failure. However, the role of lncMEG3 in DCM remains unclear. The present study was designed to investigate the role of lncMEG3 in DCM and elucidate the underlying molecular mechanisms. Methods: The diabetic mouse model was established through intraperitoneal injection streptozotocin (STZ). The heart-targeted adeno-associated virus carrying lncMEG3 interfering RNA (AAV9-shMEG3) was administered via tail-vein injection to induce silencing of lncMEG3 in diabetic mice. Echocardiography was performed to evaluate cardiac function, while hematoxylin and eosin (H&E) staining and Masson trichrome staining were employed for the detection of cardiac remodeling. The underlying mechanisms were investigated using Western blot and real-time PCR (qPCR). Results: The expression of lncMEG3 was increased in hearts with DCM and in AC16 cardiomyocytes treated with high glucose. The knockout of lncMEG3 reduced inflammation, cardiac fibrosis and myocardial hypertrophy, and improved cardiac dysfunction in diabetic mice. In diabetic mice, the activation of the nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3 (NLRP3)-inflammasome was observed, whereas silencing of lncMEG3 resulted in a reduction in NLRP3 inflammasome activation. Mechanistically, we discovered that lncMEG3 specifically functions as a competitive inhibitor of miR-223. Moreover, the use of miR-223 antisense oligonucleotide (AMO) counteracted the suppressive effects of lncMEG3 knockdown on NLRP3 inflammasome activation induced by high glucose in vitro. Conclusion: LncMEG3 exacerbates DCM by enhancing NLRP3 inflammasome activation through attenuating miR-223-mediated degradation of NLRP3 in the hearts of individuals with diabetes.

Harnessing the potential of long non-coding RNAs in the pathophysiology of Alzheimer's disease

Alzheimer's disease (AD), a diverse neurodegenerative disease, is the leading cause of dementia, accounting for 60-80 % of all cases. The pathophysiology of Alzheimer's disease is unknown, and there is no cure at this time. Recent developments in transcriptome-wide profiling have led to the identification of a number of non-coding RNAs (ncRNAs). Among these, long non-coding RNAs (lncRNAs)-long transcripts that don't seem to be able to code for proteins-have drawn attention because they function as regulatory agents in a variety of biological processes. Recent research suggests that lncRNAs play a role in the pathogenesis of Alzheimer's disease by modulating tau hyperphosphorylation, amyloid production, synaptic impairment, neuroinflammation, mitochondrial dysfunction, and oxidative stress, though their precise effects on the disorder are unknown. The biology and modes of action of the best-characterized lncRNAs in AD will be outlined here, with an emphasis on their possible involvement in the pathophysiology of the disease. As lncRNAs may offer prospective prognostic/diagnostic biomarkers and therapeutic targets for the treatment of AD, a greater comprehension of the molecular processes and the intricate network of interactions in which they are implicated could pave the way for future research.

Potential role of long noncoding RNA maternally expressed gene 3 (MEG3) in the process of neurodegeneration

Neurodegenerative diseases (ND) are complex diseases of still unknown etiology. Lately, long non-coding RNAs (lncRNAs) have become increasingly popular and implicated in several pathologies as they have several roles and appear to be involved in all biological processes such as cell signaling and cycle control as well as translation and transcription. MEG3 is one of these and acts by binding proteins or directly or competitively binding miRNAs. It has a crucial role in controlling cell death, inflammatory process, oxidative stress, endoplasmic reticulum stress, epithelial-mesenchymal transition and other processes. Recent reports showed that MEG3 is a major driving force of the necrosis phenomena in AD, causing the death of neurons, and its upregulation in cancer patients was linked to tumor suppression. Dysregulation of MEG3 affects neuronal cell death, inflammatory process, smooth muscle cell proliferation and consequently leads to the initiation or the acceleration of the disease. This review examines the current state of knowledge concerning the level of expression and the regulatory function of MEG3 in relation to several NDs. In addition, we examined the relation of MEG3 with neurotrophic factors such as Tumor growth factor β (TGFβ) and its possible mechanism of action. A comprehensive and in-depth analysis of the role of MEG3 in ND could give a clearer picture about the initiation of the process of neuronal death and help develop an alternative therapy that targets MEG3.

Virtual reality-based neuroproprioceptive physiotherapy in multiple sclerosis: a protocol for a double-arm randomised assessor-blinded controlled trial on upper extremity function, postural function and quality of life, with molecular and functional MRI assessment

INTRODUCTION

Upper limb (UL) impairment is common in people with multiple sclerosis (pwMS), and functional recovery of the UL is a key rehabilitation goal. Technology-based approaches, like virtual reality (VR), are increasingly promising. While most VR environments are task-oriented, our clinical approach integrates neuroproprioceptive 'facilitation and inhibition' (NFI) principles. To advance this, we developed immersive VR software based on NFI principles targeting UL function and sit-to-stand ability. This study aims to evaluate the effectiveness of this VR therapy compared with conventional NFI-based physical therapy in pwMS. Our study uniquely applies advanced imaging techniques, along with biological molecular assessments, to explore adaptive processes induced by VR rehabilitation.

METHODS AND ANALYSIS

This double-arm, randomised, assessor-blinded, controlled trial runs over 2 months (1 hour, 2 times per week). PwMS with mild to severe disability will receive either VR therapy or real-world physical therapy. Primary outcomes include the nine-hole peg test, box and block test, handgrip strength, tremor and five times sit-to-stand test. Secondary measures include the Multiple Sclerosis Impact Scale, the 5-level EQ-5D questionnaire and kinematic analysis. Adaptive processes will be monitored using imaging techniques (functional MRI and tractography), molecular genetic methods (long non-coding RNAs) and immune system markers (leukocytes, dendritic cells). The International Classification of Functioning, Disability and Health brief set for MS will map the bio-psycho-social context of participants.

ETHICS AND DISSEMINATION

This project and its amendments were approved by the Ethics Committee of the Institute for Clinical and Experimental Medicine and Thomayer Hospital (1983/21+4772/21 (G-21-02) and the Ethics Committee of Kralovske Vinohrady University Hospital (EK-VP/38/0/2021) in Prague, Czechia (with single enrolment). The findings of this project will be disseminated through scientific publications, conferences, professional networks, public engagement, educational materials and stakeholder briefings to ensure a broad impact across clinical, academic and public domains.

TRIAL REGISTRATION NUMBER

clinicaltrials.gov (NCT04807738).

Unveiling the predictive power of biomarkers in traumatic brain injury: A narrative review focused on clinical outcomes

Traumatic brain injury (TBI) has long-term consequences, including neurodegenerative disease risk. Current diagnostic tools are limited in detecting subtle brain damage. This review explores emerging biomarkers for TBI, including those related to neuronal injury, inflammation, EVs, and ncRNAs, evaluating their potential to predict clinical outcomes like mortality, recovery, and cognitive impairment. It addresses challenges and opportunities for implementing biomarkers in clinical practice, aiming to improve TBI diagnosis, prognosis, and treatment.

Possible involvement of a MEG3-miR-21-SPRY1-NF-κB feedback loop in spermatogenic cells proliferation, autophagy, and apoptosis

Non-obstructive azoospermia (NOA) is the most incurable form of male infertility with a complex etiology. Long non-cording RNAs (lncRNAs) were associated with regulating spermatogenesis. Herein, differentially expressed lncRNAs between NOA and control male were screened by RNA-seq analysis. MEG3 was upregulated in NOA tissues and inhibited cell proliferation and promoted cell autophagy and apoptosis in vitro. Through RNA immunoprecipitation (RIP), biotin pull-down assays, and dual-luciferase reporter assays, MEG3 was proved to act as a competing endogenous RNA of microRNA (miR)-21 and thus influenced the SPRY1/ERK/mTOR signaling pathway. Additionally, bioinformatic prediction and chip assay revealed that MEG3 was possibly regulated by nuclear factor κB (NF-κB) and SPRY1/NF-κB/MEG3 formed a feedback loop. Seminiferous tubule microinjection further investigated the effects of MEG3 on testes in vivo. These findings demonstrated that MEG3-miR-21-SPRY1-NF-κB probably acted as a feedback loop leading to azoospermia. Our study might provide a target and theoretical basis for diagnosing and treating NOA.

WTAP participates in neuronal damage by protein translation of NLRP3 in an m6A-YTHDF1-dependent manner after traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) is a common complication of acute and severe neurosurgery. Remodeling of N6-methyladenosine (m6A) stabilization may be an attractive treatment option for neurological dysfunction after TBI. In the present study, the authors explored the epigenetic methylation of RNA-mediated NLRP3 inflammasome activation after TBI.

METHODS

Neurological dysfunction, histopathology, and associated molecules were examined in conditional knockout (CKO) WTAP [flox/flox, Camk2a-cre] , WTAP flox/flox , and pAAV-U6-shRNA-YTHDF1-transfected mice. Primary neurons were used in vitro to further explore the molecular mechanisms of action of WTAP/YTHDF1 following neural damage.

RESULTS

The authors found that WTAP and m6A levels were upregulated at an early stage after TBI, and conditional deletion of WTAP in neurons did not affect neurological function but promoted functional recovery after TBI. Conditional deletion of WTAP in neurons suppressed neuroinflammation at the TBI early phase: WTAP could directly act on NLRP3 mRNA, regulate NLRP3 mRNA m6A level, and promote NLRP3 expression after neuronal injury. Further investigation found that YTH domain of YTHDF1 could directly bind to NLRP3 mRNA and regulate NLRP3 protein expression. YTHDF1 mutation or silencing improved neuronal injury, inhibited Caspase-1 activation, and decreased IL-1β levels. This effect was mediated via suppression of NLRP3 protein translation, which also reversed the stimulative effect of WTAP overexpression on NLRP3 expression and inflammation.

CONCLUSIONS

Our results indicate that WTAP participates in neuronal damage by protein translation of NLRP3 in an m6A-YTHDF1-dependent manner after TBI and that WTAP/m6A/YTHDF1 downregulation therapeutics is a viable and promising approach for preserving neuronal function after TBI, which can provide support for targeted drug development.

Breaking the vicious cycle: Targeting the NLRP3 inflammasome for treating sepsis-associated encephalopathy

Sepsis-associated encephalopathy (SAE) is a collection of clinical syndromes resulting from sepsis and characterized by widespread brain dysfunction. The high prevalence of SAE has adverse outcomes on the clinical management and prognosis of sepsis patients. However, currently, there are no effective treatments to ameliorate SAE. The pathogenesis of SAE is complex, including neuroinflammation and microglia activation, destruction of the blood-brain barrier (BBB), neurotransmitter dysfunction, cerebral metabolism and mitochondrial impairment, accumulation of amyloid beta and tauopathy, complement activation, among others. Furthermore, these mechanisms intertwine with each other, further complicating the comprehension of SAE. Among them, neuroinflammation mediated by hyperactivated microglia is considered the primary etiology of SAE. This instigates a detrimental cycle wherein BBB permeability escalates, facilitating direct damage to the central nervous system (CNS) by various neurotoxic substances. Activation of the NLRP3 inflammasome, situated within microglia, can be triggered by diverse danger signals, leading to cell pyroptosis, apoptosis, and tauopathy. These complex processes intricately regulate the onset and progression of neuroinflammation. In this review, we focus on elucidating the inhibitory regulatory mechanism of the NLRP3 inflammasome in microglia, which ultimately manifests as suppression of the inflammatory response. Our ultimate objective is to augment comprehension regarding the role of microglial NLRP3 inflammasome as we explore potential targets for therapeutic interventions against SAE.

Emerging Role of Long Noncoding RNAs in Regulating Inflammasome-Mediated Neurodegeneration in Parkinson's Disease

Parkinson's disease (PD) is one of the complex neurodegenerative disorders, primarily characterized by motor deficits, including bradykinesia, tremor, rigidity, and postural instability. The underlying pathophysiology involves the progressive loss of dopaminergic neurons within the substantia nigra pars compacta, leading to dopamine depletion in the basal ganglia circuitry. While motor symptoms are hallmark features of PD, emerging research highlights a wide range of non-motor symptoms, including cognitive impairments, mood disturbances, and autonomic dysfunctions. Inflammasome activation is pivotal in inducing neuroinflammation and promoting disease onset, progression, and severity of PD. Several studies have shown that long noncoding RNAs (lncRNAs) modulate inflammasomes in the pathogenesis of neurodegenerative diseases. Dysregulation of lncRNAs is linked to aberrant gene expression and cellular processes in neurodegeneration, causing the activation of inflammasomes that contribute to neuroinflammation and neurodegeneration. Inflammasomes are cytosolic proteins that form complexes upon activation, inducing inflammation and neuronal cell death. This review explores the significance of lncRNAs in regulating inflammasomes in PD, primarily focusing on specific lncRNAs such as nuclear paraspeckle assembly transcript 1 (NEATNEAT1), X-inactive specific transcript (XIST), growth arrest-specific 5 (GAS5), and HOX transcript antisense RNA (HOTAIR), which have been shown to activate or inhibit the NLRP3 inflammasome and induce the release of proinflammatory cytokines. Moreover, some lncRNAs mediate inflammasome activation through miRNA interactions. Understanding the roles of lncRNAs in inflammasome regulation provides new therapeutic targets for controlling neuroinflammation and reducing the progression of neurodegeneration. Identifying lncRNA-mediated regulatory pathways paves the way for novel therapies in the battle against these devastating neurodegenerative disorders.

The role of exosome-shuttled miRNAs in heavy metal-induced peripheral tissues and neuroinflammation in Alzheimer's disease

Heavy metal-induced neuroinflammation is a significant pathophysiologic mechanism in Alzheimer's disease (AD). Microglia-mediated neuroinflammation plays a crucial role in the pathogenesis of AD. Multiple miRNAs are differentially expressed in peripheral tissues after heavy metal exposure, and increasing evidence suggests that they are involved in AD progression by regulating microglial homeostasis. Exosomes, which are capable of loading miRNAs and crossing the bloodbrain barrier, serve as mediators of communication between peripheral tissues and the brain. In this review, we summarize the current evidence on the link between miRNAs in peripheral tissues and neuroinflammation in AD after heavy metal exposure and propose a role for miRNAs in the microglial neurodegenerative phenotype (MGnD) of AD. This study will help to elucidate the link between peripheral tissue damage and MGnD-mediated neuroinflammation in AD after heavy metal exposure. Additionally, we summarize the regulatory effects of natural compounds on peripheral tissue-derived miRNAs, which could be potential therapeutic targets for natural compounds to regulate peripheral tissue-derived exosomal miRNAs to ameliorate heavy metal-induced MGnD-mediated neuroinflammation in patients with AD after heavy metal exposure.

Multifaceted roles of Meg3 in cellular senescence and atherosclerosis

BACKGROUND AND AIMS

Long noncoding RNAs are involved in the pathogenesis of atherosclerosis. As long noncoding RNAs maternally expressed gene 3 (Meg3) prevents cellular senescence of hepatic vascular endothelium and obesity-induced insulin resistance, we decided to examine its role in cellular senescence and atherosclerosis.

METHODS AND RESULTS

By analyzing our data and human and mouse data from the Gene Expression Omnibus database, we found that Meg3 expression was reduced in humans and mice with cardiovascular disease, indicating its potential role in atherosclerosis. In Ldlr-/- mice fed a Western diet for 12 weeks, Meg3 silencing by chemically modified antisense oligonucleotides attenuated the formation of atherosclerotic lesions by 34.9% and 20.1% in male and female mice, respectively, revealed by en-face Oil Red O staining, which did not correlate with changes in plasma lipid profiles. Real-time quantitative PCR analysis of cellular senescence markers p21 and p16 revealed that Meg3 deficiency aggravates hepatic cellular senescence but not cellular senescence at aortic roots. Human Meg3 transgenic mice were generated to examine the role of Meg3 gain-of-function in the development of atherosclerosis induced by PCSK9 overexpression. Meg3 overexpression promotes atherosclerotic lesion formation by 29.2% in Meg3 knock-in mice independent of its effects on lipid profiles. Meg3 overexpression inhibits hepatic cellular senescence, while it promotes aortic cellular senescence likely by impairing mitochondrial function and delaying cell cycle progression.

CONCLUSIONS

Our data demonstrate that Meg3 promotes the formation of atherosclerotic lesions independent of its effects on plasma lipid profiles. In addition, Meg3 regulates cellular senescence in a tissue-specific manner during atherosclerosis. Thus, we demonstrated that Meg3 has multifaceted roles in cellular senescence and atherosclerosis.

Extracellular vesicles as carriers for noncoding RNA-based regulation of macrophage/microglia polarization: an emerging candidate regulator for lung and traumatic brain injuries

Macrophage/microglia function as immune defense and homeostatic cells that originate from bone marrow progenitor cells. Macrophage/microglia activation is historically divided into proinflammatory M1 or anti-inflammatory M2 states based on intracellular dynamics and protein production. The polarization of macrophages/microglia involves a pivotal impact in modulating the development of inflammatory disorders, namely lung and traumatic brain injuries. Recent evidence indicates shared signaling pathways in lung and traumatic brain injuries, regulated through non-coding RNAs (ncRNAs) loaded into extracellular vesicles (EVs). This packaging protects ncRNAs from degradation. These vesicles are subcellular components released through a paracellular mechanism, constituting a group of nanoparticles that involve exosomes, microvesicles, and apoptotic bodies. EVs are characterized by a double-layered membrane and are abound with proteins, nucleic acids, and other bioactive compounds. ncRNAs are RNA molecules with functional roles, despite their absence of coding capacity. They actively participate in the regulation of mRNA expression and function through various mechanisms. Recent studies pointed out that selective packaging of ncRNAs into EVs plays a role in modulating distinct facets of macrophage/microglia polarization, under conditions of lung and traumatic brain injuries. This study will explore the latest findings regarding the role of EVs in the progression of lung and traumatic brain injuries, with a specific focus on the involvement of ncRNAs within these vesicles. The conclusion of this review will emphasize the clinical opportunities presented by EV-ncRNAs, underscoring their potential functions as both biomarkers and targets for therapeutic interventions.

E3 ubiquitin ligase Herc3 deficiency leads to accumulation of subretinal microglia and retinal neurodegeneration

Activated microglia have been implicated in the pathogenesis of age-related macular degeneration (AMD), diabetic retinopathy, and other neurodegenerative and neuroinflammatory disorders, but our understanding of the mechanisms behind their activation is in infant stages. With the goal of identifying novel genes associated with microglial activation in the retina, we applied a semiquantitative fundus spot scoring scale to an unbiased, state-of-the-science mouse forward genetics pipeline. A mutation in the gene encoding the E3 ubiquitin ligase Herc3 led to prominent accumulation of fundus spots. CRISPR mutagenesis was used to generate Herc3-/- mice, which developed prominent accumulation of fundus spots and corresponding activated Iba1 + /CD16 + subretinal microglia, retinal thinning on OCT and histology, and functional deficits by Optomotory and electrophysiology. Bulk RNA sequencing identified activation of inflammatory pathways and differentially expressed genes involved in the modulation of microglial activation. Thus, despite the known expression of multiple E3 ubiquitin ligases in the retina, we identified a non-redundant role for Herc3 in retinal homeostasis. Our findings are significant given that a dysregulated ubiquitin-proteasome system (UPS) is important in prevalent retinal diseases, in which activated microglia appear to play a role. This association between Herc3 deficiency, retinal microglial activation and retinal degeneration merits further study.

Long Noncoding RNA VLDLR-AS1 Levels in Serum Correlate with Combat-Related Chronic Mild Traumatic Brain Injury and Depression Symptoms in US Veterans

More than 75% of traumatic brain injuries (TBIs) are mild (mTBI) and military service members often experience repeated combat-related mTBI. The chronic comorbidities concomitant with repetitive mTBI (rmTBI) include depression, post-traumatic stress disorder or neurological dysfunction. This study sought to determine a long noncoding RNA (lncRNA) expression signature in serum samples that correlated with rmTBI years after the incidences. Serum samples were obtained from Long-Term Impact of Military-Relevant Brain-Injury Consortium Chronic Effects of Neurotrauma Consortium (LIMBIC CENC) repository, from participants unexposed to TBI or who had rmTBI. Four lncRNAs were identified as consistently present in all samples, as detected via droplet digital PCR and packaged in exosomes enriched for CNS origin. The results, using qPCR, demonstrated that the lncRNA VLDLR-AS1 levels were significantly lower among individuals with rmTBI compared to those with no lifetime TBI. ROC analysis determined an AUC of 0.74 (95% CI: 0.6124 to 0.8741; p = 0.0012). The optimal cutoff for VLDLR-AS1 was ≤153.8 ng. A secondary analysis of clinical data from LIMBIC CENC was conducted to evaluate the psychological symptom burden, and the results show that lncRNAs VLDLR-AS1 and MALAT1 are correlated with symptoms of depression. In conclusion, lncRNA VLDLR-AS1 may serve as a blood biomarker for identifying chronic rmTBI and depression in patients.

Role of regulatory non-coding RNAs in traumatic brain injury

Traumatic brain injury (TBI) is a potentially fatal health event that cannot be predicted in advance. After TBI occurs, it can have enduring consequences within both familial and social spheres. Yet, despite extensive efforts to improve medical interventions and tailor healthcare services, TBI still remains a major contributor to global disability and mortality rates. The prompt and accurate diagnosis of TBI in clinical contexts, coupled with the implementation of effective therapeutic strategies, remains an arduous challenge. However, a deeper understanding of changes in gene expression and the underlying molecular regulatory processes may alleviate this pressing issue. In recent years, the study of regulatory non-coding RNAs (ncRNAs), a diverse class of RNA molecules with regulatory functions, has been a potential game changer in TBI research. Notably, the identification of microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and other ncRNAs has revealed their potential as novel diagnostic biomarkers and therapeutic targets for TBI, owing to their ability to regulate the expression of numerous genes. In this review, we seek to provide a comprehensive overview of the functions of regulatory ncRNAs in TBI. We also summarize regulatory ncRNAs used for treatment in animal models, as well as miRNAs, lncRNAs, and circRNAs that served as biomarkers for TBI diagnosis and prognosis. Finally, we discuss future challenges and prospects in diagnosing and treating TBI patients in the clinical settings.

LncRNA MEG3: Targeting the Molecular Mechanisms and Pathogenic causes of Metabolic Diseases

BACKGROUND

Non-coding RNA is a type of RNA that does not encode proteins, distributed among rRNA, tRNA, snRNA, snoRNA, microRNA and other RNAs with identified functions, where the Long non-coding RNA (lncRNA) displays a nucleotide length over 200. LncRNAs enable multiple biological processes in the human body, including cancer cell invasion and metastasis, apoptosis, cell autophagy, inflammation, etc. Recently, a growing body of studies has demonstrated the association of lncRNAs with obesity and obesity-induced insulin resistance and NAFLD, where MEG3 is related to glucose metabolism, such as insulin resistance. In addition, MEG3 has been demonstrated in the pathological processes of various cancers, such as mediating inflammation, cardiovascular disease, liver disease and other metabolic diseases.

OBJECTIVE

To explore the regulatory role of lncRNA MEG3 in metabolic diseases. It provides new ideas for clinical treatment or experimental research.

METHODS

In this paper, in order to obtain enough data, we integrate and analyze the data in the PubMed database.

RESULTS

LncRNA MEG3 can regulate many metabolic diseases, such as insulin resistance, NAFLD, inflammation and so on.

CONCLUSION

LncRNA MEG3 has a regulatory role in a variety of metabolic diseases, which are currently difficult to be completely cured, and MEG3 is a potential target for the treatment of these diseases. Here, we review the role of lncRNA MEG3 in mechanisms of action and biological functions in human metabolic diseases.

Silencing of LINC00707 Alleviates Brain Injury by Targeting miR-30a-5p to Regulate Microglia Inflammation and Apoptosis

The role of microglia in traumatic brain injury (TBI) has gained considerable attention. The present study aims to elucidate the potential mechanisms of Long intergenic non-protein coding RNA 707 (LINC00707) in TBI-induced microglia activation and inflammatory factor release. An in vivo model of rat TBI and in vitro microglia model was established using Controlled cortex injury (CCI) and lipopolysaccharide (LPS) stimulation. RT-qPCR to detect LINC00707 levels in rat cerebral cortex or cells. Modified Neurological Impairment Score (mNSS) and Morris Water Maze test was conducted to assess the neurological deficits and cognitive impairment. ELISA analysis of pro-inflammatory factors levels. CCK-8 and flow cytometry for cell viability and apoptosis levels. Dual-luciferase report and RIP assay to validate the targeting relationship between LINC00707 and miR-30a-5p. LINC00707 was elevated in the TBI rat cerebral cortex and LPS-induced microglia, while miR-30a-5p was noticeably decreased (P < 0.05). Increased mNSS, cognitive dysfunction, and brain edema in TBI rats were all prominently reversed by silencing of LINC00707, but this reversal was partially abrogated by decreasing miR-30a-5p (P < 0.05). Inhibition of LINC00707 suppressed the overproduction of inflammatory factors in TBI rats (P < 0.05). LPS decreased microglial cell viability, increased apoptosis, and promoted inflammatory overproduction than control, but the silencing of LINC00707 reversed its effect. Suppression of miR-30a-5p attenuated this reversal (P < 0.05). miR-30a-5p was the target miRNA of LINC00707. All in all, the results suggested that inhibiting LINC00707/miR-30a-5p axis could alleviate the progression of TBI by suppressing the inflammation and apoptosis of microglia cells.

Roles of microRNA-124 in traumatic brain injury: a comprehensive review

Traumatic brain injury (TBI) is a prominent global cause of mortality due to the limited availability of effective prevention and treatment strategies for this disorder. An effective molecular biomarker may contribute to determining the prognosis and promoting the therapeutic efficiency of TBI. MicroRNA-124 (miR-124) is most abundantly expressed in the brain and exerts different biological effects in a variety of diseases by regulating pathological processes of apoptosis and proliferation. Recently, increasing evidence has demonstrated the association between miR-124 and TBI, but there is still a lack of relevant literature to summarize the current evidence on this topic. Based on this review, we found that miR-124 was involved as a regulatory factor in cell apoptosis and proliferation, and was also strongly related with the pathophysiological development of TBI. MiR-124 played an essential role in TBI by interacting with multiple biomolecules and signaling pathways, such as JNK, VAMP-3, Rela/ApoE, PDE4B/mTOR, MDK/TLR4/NF-κB, DAPK1/NR2B, JAK/STAT3, PI3K/AKT, Ras/MEK/Erk. The potential benefits of upregulating miR-124 in facilitating TBI recovery have been identified. The advancement of miRNA nanocarrier system technology presents an opportunity for miR-124 to emerge as a novel therapeutic target for TBI. However, the specific mechanisms underlying the role of miR-124 in TBI necessitate further investigation. Additionally, comprehensive large-scale studies are required to evaluate the clinical significance of miR-124 as a therapeutic target for TBI.

Molecular consequences of peripheral Influenza A infection on cell populations in the murine hypothalamus

Infection with Influenza A virus (IAV) causes the well-known symptoms of the flu, including fever, loss of appetite, and excessive sleepiness. These responses, mediated by the brain, will normally disappear once the virus is cleared from the system, but a severe respiratory virus infection may cause long-lasting neurological disturbances. These include encephalitis lethargica and narcolepsy. The mechanisms behind such long lasting changes are unknown. The hypothalamus is a central regulator of the homeostatic response during a viral challenge. To gain insight into the neuronal and non-neuronal molecular changes during an IAV infection, we intranasally infected mice with an H1N1 virus and extracted the brain at different time points. Using single-nucleus RNA sequencing (snRNA-seq) of the hypothalamus, we identify transcriptional effects in all identified cell populations. The snRNA-seq data showed the most pronounced transcriptional response at 3 days past infection, with a strong downregulation of genes across all cell types. General immune processes were mainly impacted in microglia, the brain resident immune cells, where we found increased numbers of cells expressing pro-inflammatory gene networks. In addition, we found that most neuronal cell populations downregulated genes contributing to the energy homeostasis in mitochondria and protein translation in the cytosol, indicating potential reduced cellular and neuronal activity. This might be a preventive mechanism in neuronal cells to avoid intracellular viral replication and attack by phagocytosing cells. The change of microglia gene activity suggest that this is complemented by a shift in microglia activity to provide increased surveillance of their surroundings.

LncRNAs and PTEN/PI3K signaling: A symphony of regulation in cancer biology

The Emergence of Long Non-coding RNAs (lncRNAs) as Key Regulators in Diverse Biological Processes: A Paradigm Shift in Understanding Gene Expression and its Impact on Cancer. The PTEN/PI3K pathway, a pivotal signaling cascade involved in cancer progression, orchestrates critical cellular functions such as survival, proliferation, and growth. In light of these advances, our investigation delves into the intricate and multifaceted interplay between lncRNAs and the PTEN/PI3K signaling pathway, unearthing previously undisclosed mechanisms that underpin cancer growth and advancement. These elusive lncRNAs exert their influence through direct targeting of the PTEN/PI3K pathway or by skillfully regulating the expression and activity of specific lncRNAs. This comprehensive review underscores the paramount significance of the interaction between lncRNAs and the PTEN/PI3K signaling pathway in cancer biology, unveiling an auspicious avenue for novel diagnostic tools and targeted therapeutic interventions. In this review, we navigate through the functional roles of specific lncRNAs in modulating PTEN/PI3K expression and activity. Additionally, we scrutinize their consequential effects on downstream components of the PTEN/PI3K pathway, unraveling the intricacies of their mutual regulation. By advancing our understanding of this complex regulatory network, this study holds the potential to revolutionize the landscape of cancer research, paving the way for tailored and efficacious treatments to combat this devastating disease.

Roles of Non-Coding RNA in Alzheimer's Disease Pathophysiology

Alzheimer's disease (AD) is a chronic neurodegenerative disorder that is accompanied by deficits in memory and cognitive functions. The disease is pathologically characterised by the accumulation and aggregation of an extracellular peptide referred to as amyloid-β (Aβ) in the form of amyloid plaques and the intracellular aggregation of a hyperphosphorelated protein tau in the form of neurofibrillary tangles (NFTs) that cause neuroinflammation, synaptic dysfunction, and oxidative stress. The search for pathomechanisms leading to disease onset and progression has identified many key players that include genetic, epigenetic, behavioural, and environmental factors, which lend support to the fact that this is a multi-faceted disease where failure in various systems contributes to disease onset and progression. Although the vast majority of individuals present with the sporadic (non-genetic) form of the disease, dysfunctions in numerous protein-coding and non-coding genes have been implicated in mechanisms contributing to the disease. Recent studies have provided strong evidence for the association of non-coding RNAs (ncRNAs) with AD. In this review, we highlight the current findings on changes observed in circular RNA (circRNA), microRNA (miRNA), short interfering RNA (siRNA), piwi-interacting RNA (piRNA), and long non-coding RNA (lncRNA) in AD. Variations in these ncRNAs could potentially serve as biomarkers or therapeutic targets for the diagnosis and treatment of Alzheimer's disease. We also discuss the results of studies that have targeted these ncRNAs in cellular and animal models of AD with a view for translating these findings into therapies for Alzheimer's disease.

Long non-coding RNA MEG3 alleviates postoperative cognitive dysfunction by suppressing inflammatory response and oxidative stress via has-miR-106a-5p/SIRT3

Postoperative cognitive dysfunction (POCD), a neurological complication after surgery, is common among the elderly in particular. Maternal expression gene 3 (MEG3) is a novel long non-coding RNA (lncRNA) that contributes to glial cell activation and inflammation. We aim to further explore its role in POCD. Mice were induced with sevoflurane anesthesia and underwent orthopedic surgery to establish a POCD model. BV-2 microglia activation was induced by lipopolysaccharide. The overexpressed lentiviral plasmid lv-MEG3 and its control were injected into mice. pcDNA3.1-MEG3, has-miR-106a-5p mimic, and its negative control were transfected into BV-2 cells. The expressions of has-miR-106a-5p MEG3 and Sirtuin 3 (SIRT3) in rat hippocampus and BV-2 cells were quantitatively detected. Levels of SIRT3, TNF-α, and IL-1β were detected by western blot, levels of TNF-α and IL-1β by ELISA, and expression of GSH-Px, SOD, and MDA by kits. The targeting relationship between MEG3 and has-miR-106a-5p was confirmed using bioinformatics and dual-luciferase reporter assay. LncRNA MEG3 was down-regulated in POCD mice, whereas has-miR-106a-5 levels were up-regulated. Overexpression of MEG3 could attenuate cognitive dysfunction and inflammatory response in POCD mice, inhibit lipopolysaccharide-induced inflammatory response and oxidative stress in BV-2 cells, and promote has-miR-106a through competitive binding with has-miR-106a-5-5 expression of target gene SIRT3. Overexpression of has-miR-106a-5p had a reverse effect on overexpression of MEG3 functioning on lipopolysaccharide-induced BV-2 cells. LncRNA MEG3 could inhibit the inflammatory response and oxidative stress via has-miR-106a-5p/SIRT3, thereby reducing POCD, which might be a potential biological target for the diagnosis and treatment of clinical POCD.

Non-coding RNAs and Exosomal Non-coding RNAs in Traumatic Brain Injury: the Small Player with Big Actions

Nowadays, there is an increasing concern regarding traumatic brain injury (TBI) worldwide since substantial morbidity is observed after it, and the long-term consequences that are not yet fully recognized. A number of cellular pathways related to the secondary injury in brain have been identified, including free radical production (owing to mitochondrial dysfunction), excitotoxicity (regulated by excitatory neurotransmitters), apoptosis, and neuroinflammatory responses (as a result of activation of the immune system and central nervous system). In this context, non-coding RNAs (ncRNAs) maintain a fundamental contribution to post-transcriptional regulation. It has been shown that mammalian brains express high levels of ncRNAs that are involved in several brain physiological processes. Furthermore, altered levels of ncRNA expression have been found in those with traumatic as well non-traumatic brain injuries. The current review highlights the primary molecular mechanisms participated in TBI that describes the latest and novel results about changes and role of ncRNAs in TBI in both clinical and experimental research.

NLRP3 Inflammasome’s Activation in Acute and Chronic Brain Diseases—An Update on Pathogenetic Mechanisms and Therapeutic Perspectives with Respect to Other Inflammasomes

Increasingly prevalent acute and chronic human brain diseases are scourges for the elderly. Besides the lack of therapies, these ailments share a neuroinflammation that is triggered/sustained by different innate immunity-related protein oligomers called inflammasomes. Relevant neuroinflammation players such as microglia/monocytes typically exhibit a strong NLRP3 inflammasome activation. Hence the idea that NLRP3 suppression might solve neurodegenerative ailments. Here we review the recent Literature about this topic. First, we update conditions and mechanisms, including RNAs, extracellular vesicles/exosomes, endogenous compounds, and ethnic/pharmacological agents/extracts regulating NLRP3 function. Second, we pinpoint NLRP3-activating mechanisms and known NLRP3 inhibition effects in acute (ischemia, stroke, hemorrhage), chronic (Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, MS, ALS), and virus-induced (Zika, SARS-CoV-2, and others) human brain diseases. The available data show that (i) disease-specific divergent mechanisms activate the (mainly animal) brains NLRP3; (ii) no evidence proves that NLRP3 inhibition modifies human brain diseases (yet ad hoc trials are ongoing); and (iii) no findings exclude that concurrently activated other-than-NLRP3 inflammasomes might functionally replace the inhibited NLRP3. Finally, we highlight that among the causes of the persistent lack of therapies are the species difference problem in disease models and a preference for symptomatic over etiologic therapeutic approaches. Therefore, we posit that human neural cell-based disease models could drive etiological, pathogenetic, and therapeutic advances, including NLRP3’s and other inflammasomes’ regulation, while minimizing failure risks in candidate drug trials.

The Implications of Microglial Regulation in Neuroplasticity-Dependent Stroke Recovery

Stroke causes varying degrees of neurological deficits, leading to corresponding dysfunctions. There are different therapeutic principles for each stage of pathological development. Neuroprotection is the main treatment in the acute phase, and functional recovery becomes primary in the subacute and chronic phases. Neuroplasticity is considered the basis of functional restoration and neurological rehabilitation after stroke, including the remodeling of dendrites and dendritic spines, axonal sprouting, myelin regeneration, synapse shaping, and neurogenesis. Spatiotemporal development affects the spontaneous rewiring of neural circuits and brain networks. Microglia are resident immune cells in the brain that contribute to homeostasis under physiological conditions. Microglia are activated immediately after stroke, and phenotypic polarization changes and phagocytic function are crucial for regulating focal and global brain inflammation and neurological recovery. We have previously shown that the development of neuroplasticity is spatiotemporally consistent with microglial activation, suggesting that microglia may have a profound impact on neuroplasticity after stroke and may be a key therapeutic target for post-stroke rehabilitation. In this review, we explore the impact of neuroplasticity on post-stroke restoration as well as the functions and mechanisms of microglial activation, polarization, and phagocytosis. This is followed by a summary of microglia-targeted rehabilitative interventions that influence neuroplasticity and promote stroke recovery.

The Common LncRNAs of Neuroinflammation-Related Diseases

Spatio-temporal specific long noncoding RNAs (lncRNAs) play important regulatory roles not only in the growth and development of the brain but also in the occurrence and development of neurologic diseases. Generally, the occurrence of neurologic diseases is accompanied by neuroinflammation. Elucidation of the regulatory mechanisms of lncRNAs on neuroinflammation is helpful for the clinical treatment of neurologic diseases. This paper focuses on recent findings on the regulatory effect of lncRNAs on neuroinflammatory diseases and selects 10 lncRNAs that have been intensively studied to analyze their mechanism action. The clinical treatment status of lncRNAs as drug targets is also reviewed. SIGNIFICANCE STATEMENT: Gene therapies such as clustered regularly interspaced short palindrome repeats technology, antisense RNA technology, and RNAi technology are gradually applied in clinical treatment, and the development of technology is based on a large number of basic research investigations. This paper focuses on the mechanisms of lncRNAs regulation of neuroinflammation, elucidates the beneficial or harmful effects of lncRNAs in neurosystemic diseases, and provides theoretical bases for lncRNAs as drug targets.

Regulation of Glial Function by Noncoding RNA in Central Nervous System Disease

Non-coding RNAs (ncRNAs) are a class of functional RNAs that play critical roles in different diseases. NcRNAs include microRNAs, long ncRNAs, and circular RNAs. They are highly expressed in the brain and are involved in the regulation of physiological and pathophysiological processes of central nervous system (CNS) diseases. Mounting evidence indicates that ncRNAs play key roles in CNS diseases. Further elucidating the mechanisms of ncRNA underlying the process of regulating glial function that may lead to the identification of novel therapeutic targets for CNS diseases.

MicroRNA-7a-5p ameliorates diabetic peripheral neuropathy by regulating VDAC1/JNK/c-JUN pathway

AIMS

The pathogenesis of diabetic peripheral neuropathy (DPN) is complex, and its treatment is extremely challenging. MicroRNA-7a-5p (miR-7a-5p) has been widely reported to alleviate apoptosis and oxidative stress in various diseases. This study aimed to investigate the mechanism of miR-7a-5p in DPN.

METHODS

DPN cell model was constructed with high-glucose-induced RSC96 cells. Cell apoptosis and viability were detected by flow cytometry analysis and cell counting kit-8 (CCK-8) assay respectively. The apoptosis and Jun N-terminal kinase (JNK)/c-JUN signalling pathway-related proteins expression were detected by Western blotting. The intracellular calcium content and oxidative stress levels were detected by flow cytometry and reagent kits. Mitochondrial membrane potential was evaluated by tetrechloro-tetraethylbenzimidazol carbocyanine iodide (JC-1) staining. The targeting relationship between miR-7a-5p and voltage-dependent anion-selective channel protein 1 (VDAC1) was determined by RNA pull-down assay and dual-luciferase reporter gene assay. The streptozotocin (STZ) rat model was constructed to simulate DPN in vivo. The paw withdrawal mechanical threshold (PTW) was measured by Frey capillary line, and the motor nerve conduction velocity (MNCV) was measured by electromyography.

RESULTS

MiR-7a-5p expression was decreased, while VDAC1 expression was increased in HG-induced RSC96 cells and STZ rats. In HG-induced RSC96 cells, miR-7a-5p overexpression promoted cell proliferation, inhibited apoptosis, down-regulated calcium release, improved mitochondrial membrane potential and repressed oxidative stress response. MiR-7a-5p negatively regulated VDAC1 expression. VDAC1 knockdown improved cell proliferation activity, suppressed cell apoptosis and mitochondrial dysfunction by inhibiting JNK/c-JUN pathway activation. MiR-7a-5p overexpression raised PTW, restored MNCV and reduced oxidative stress levels and nerve cell apoptosis in STZ rats.

CONCLUSION

MiR-7a-5p overexpression ameliorated mitochondrial dysfunction and inhibited apoptosis in DPN by regulating VDAC1/JNK/c-JUN pathway.

Astrocytic MicroRNAs and Transcription Factors in Alzheimer's Disease and Therapeutic Interventions

Astrocytes are important for maintaining cholesterol metabolism, glutamate uptake, and neurotransmission. Indeed, inflammatory processes and neurodegeneration contribute to the altered morphology, gene expression, and function of astrocytes. Astrocytes, in collaboration with numerous microRNAs, regulate brain cholesterol levels as well as glutamatergic and inflammatory signaling, all of which contribute to general brain homeostasis. Neural electrical activity, synaptic plasticity processes, learning, and memory are dependent on the astrocyte-neuron crosstalk. Here, we review the involvement of astrocytic microRNAs that potentially regulate cholesterol metabolism, glutamate uptake, and inflammation in Alzheimer's disease (AD). The interaction between astrocytic microRNAs and long non-coding RNA and transcription factors specific to astrocytes also contributes to the pathogenesis of AD. Thus, astrocytic microRNAs arise as a promising target, as AD conditions are a worldwide public health problem. This review examines novel therapeutic strategies to target astrocyte dysfunction in AD, such as lipid nanodiscs, engineered G protein-coupled receptors, extracellular vesicles, and nanoparticles.

A review of current evidence about lncRNA MEG3: A tumor suppressor in multiple cancers

Long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) is a lncRNA located at the DLK1-MEG3 site of human chromosome 14q32.3. The expression of MEG3 in various tumors is substantially lower than that in normal adjacent tissues, and deletion of MEG3 expression is involved in the occurrence of many tumors. The high expression of MEG3 could inhibit the occurrence and development of tumors through several mechanisms, which has become a research hotspot in recent years. As a member of tumor suppressor lncRNAs, MEG3 is expected to be a new target for tumor diagnosis and treatment. This review discusses the molecular mechanisms of MEG3 in different tumors and future challenges for the diagnosis and treatment of cancers through MEG3.

LncRNA MEG3: Potential stock for precision treatment of cardiovascular diseases

The prevalence and mortality rates of cardiovascular diseases are increasing, and new treatment strategies are urgently needed. From the perspective of basic pathogenesis, the occurrence and development of cardiovascular diseases are related to inflammation, apoptosis, fibrosis and autophagy of cardiomyocytes, endothelial cells and other related cells. The involvement of maternally expressed gene 3 (MEG3) in human disease processes has been increasingly reported. P53 and PI3K/Akt are important pathways by which MEG3 participates in regulating cell apoptosis. MEG3 directly or competitively binds with miRNA to participate in apoptosis, inflammation, oxidative stress, endoplasmic reticulum stress, EMT and other processes. LncRNA MEG3 is mainly involved in malignant tumors, metabolic diseases, immune system diseases, cardiovascular and cerebrovascular diseases, etc., LncRNA MEG3 has a variety of pathological effects in cardiomyocytes, fibroblasts and endothelial cells and has great clinical application potential in the prevention and treatment of AS, MIRI, hypertension and HF. This paper will review the research progress of MEG3 in the aspects of mechanism of action, other systemic diseases and cardiovascular diseases, and point out its great potential in the prevention and treatment of cardiovascular diseases. lncRNAs also play a role in endothelial cells. In addition, lncRNA MEG3 has shown biomarker value, prognostic value and therapeutic response measurement in tumor diseases. We boldly speculate that MEG3 will play a role in the emerging discipline of tumor heart disease.

Role of Long Noncoding RNAs in the Regulation of Cellular Immune Response and Inflammatory Diseases

Long noncoding RNAs (lncRNAs) are recently discovered genetic regulatory molecules that regulate immune responses and are closely associated with the occurrence and development of various diseases, including inflammation, in humans and animals. Under specific physiological conditions, lncRNA expression varies at the cell or tissue level, and lncRNAs can bind to specific miRNAs, target mRNAs, and target proteins to participate in certain processes, such as cell differentiation and inflammatory responses, via the corresponding signaling pathways. This review article summarizes the regulatory role of lncRNAs in macrophage polarization, dendritic cell differentiation, T cell differentiation, and endothelial and epithelial inflammation. In addition, it describes the molecular mechanism of lncRNAs in acute kidney injury, hepatitis, inflammatory injury of the lung, osteoarthritis, mastitis, and neuroinflammation to provide a reference for the molecular regulatory network as well as the genetic diagnosis and treatment of inflammatory diseases in humans and animals.

A systematic review of the research progress of non-coding RNA in neuroinflammation and immune regulation in cerebral infarction/ischemia-reperfusion injury

Cerebral infarction/ischemia-reperfusion injury is currently the disease with the highest mortality and disability rate of cardiovascular disease. Current studies have shown that nerve cells die of ischemia several hours after ischemic stroke, which activates the innate immune response in the brain, promotes the production of neurotoxic substances such as inflammatory cytokines, chemokines, reactive oxygen species and − nitrogen oxide, and mediates the destruction of blood-brain barrier and the occurrence of a series of inflammatory cascade reactions. Meanwhile, the expression of adhesion molecules in cerebral vascular endothelial cells increased, and immune inflammatory cells such as polymorphonuclear neutrophils, lymphocytes and mononuclear macrophages passed through vascular endothelial cells and entered the brain tissue. These cells recognize antigens exposed by the central nervous system in the brain, activate adaptive immune responses, and further mediate secondary neuronal damage, aggravating neurological deficits. In order to reduce the above-mentioned damage, the body induces peripheral immunosuppressive responses through negative feedback, which increases the incidence of post-stroke infection. This process is accompanied by changes in the immune status of the ischemic brain tissue in local and systemic systems. A growing number of studies implicate noncoding RNAs (ncRNAs) as novel epigenetic regulatory elements in the dysfunction of various cell subsets in the neurovascular unit after cerebral infarction/ischemia-reperfusion injury. In particular, recent studies have revealed advances in ncRNA biology that greatly expand the understanding of epigenetic regulation of immune responses and inflammation after cerebral infarction/ischemia-reperfusion injury. Identification of aberrant expression patterns and associated biological effects of ncRNAs in patients revealed their potential as novel biomarkers and therapeutic targets for cerebral infarction/ischemia-reperfusion injury. Therefore, this review systematically presents recent studies on the involvement of ncRNAs in cerebral infarction/ischemia-reperfusion injury and neuroimmune inflammatory cascades, and elucidates the functions and mechanisms of cerebral infarction/ischemia-reperfusion-related ncRNAs, providing new opportunities for the discovery of disease biomarkers and targeted therapy. Furthermore, this review introduces clustered regularly interspaced short palindromic repeats (CRISPR)-Display as a possible transformative tool for studying lncRNAs. In the future, ncRNA is expected to be used as a target for diagnosing cerebral infarction/ischemia-reperfusion injury, judging its prognosis and treatment, thereby significantly improving the prognosis of patients.

LncRNA, an Emerging Approach for Neurological Diseases Treatment by Regulating Microglia Polarization

Neurological disorders cause untold human disability and death each year. For most neurological disorders, the efficacy of their primary treatment strategies remains suboptimal. Microglia are associated with the development and progression of multiple neurological disorders. Targeting the regulation of microglia polarization has emerged as an important therapeutic strategy for neurological disorders. Their pro-inflammatory (M1)/anti-inflammatory (M2) phenotype microglia are closely associated with neuronal apoptosis, synaptic plasticity, blood-brain barrier integrity, resistance to iron death, and astrocyte regulation. LncRNA, a recently extensively studied non-coding transcript of over 200 nucleotides, has shown great value to intervene in microglia polarization. It can often participate in gene regulation of microglia by directly regulating transcription or sponging downstream miRNAs, for example. Through proper regulation, microglia can exert neuroprotective effects, reduce neurological damage and improve the prognosis of many neurological diseases. This paper reviews the progress of research linking lncRNAs to microglia polarization and neurological diseases.

Bioinformatics-based analysis reveals IDR-1018-mediated ceRNA regulation network for protective effect on hypoxia-ischemic brain injury in neonatal mice

Activation of an innate immune response serves as a key, contributing factor in perinatal brain injury. The current study sought to evaluate the clinical significance of innate defense regulatory peptide 1018 (IDR-1018)-derived peptide mediating ceRNA regulation network as a biomarker in neonatal mice with hypoxic-ischemic brain damage (HIBD). Firstly, bioinformatics analyses were performed to screen the HIBD-related candidate genes, miRNAs, and lncRNAs. The StarBase, miRDB, and LncBase databases were retrieved to obtain the lncRNA-miRNA-mRNA network, which revealed the ceRNA regulatory network mediated by IDR-1018. Subsequently, RT-qPCR was adopted to determine the expression patterns of MIAT, miR-7a-5p, and Plp2 in neonatal mice with HIBD after treatment with IDR-1018. Moreover, the relationship among mRNA, miRNA, and lncRNA in primary hippocampal neurons was verified by means of dual-luciferase reporter assay and RIP assay. Initial findings demonstrated that Plp2, mmu-miR-7a-5p, and three lncRNAs (MIAT, XIST, and 1700020I14RIK) were related to HIBD. Moreover, IDR-1018 could relieve HIBD in neonatal mice. Plp2 and MIAT were down-regulated, while mmu-miR-7a-5p was up-regulated in the striatum, hippocampus, and cortical tissues of the neonatal mice with HIBD, whereas treatment with the IDR-1018 could revere these trends. Additionally, MIAT acted as a ceRNA of miR-7a-5p to elevate Plp2 expression. In conclusion, our findings highlighted that IDR-1018 relieved HIBD in neonatal mice via the MIAT/miR-7a-5p/Plp2 axis.

Targeting NLRP3 Inflammasome With Nrf2 Inducers in Central Nervous System Disorders

The NLRP3 inflammasome is an intracellular multiprotein complex that plays an essential role in the innate immune system by identifying and eliminating a plethora of endogenous and exogenous threats to the host. Upon activation of the NLRP3 complex, pro-inflammatory cytokines are processed and released. Furthermore, activation of the NLRP3 inflammasome complex can induce pyroptotic cell death, thereby propagating the inflammatory response. The aberrant activity and detrimental effects of NLRP3 inflammasome activation have been associated with cardiovascular, neurodegenerative, metabolic, and inflammatory diseases. Therefore, clinical strategies targeting the inhibition of the self-propelled NLRP3 inflammasome activation are required. The transcription factor Nrf2 regulates cellular stress response, controlling the redox equilibrium, metabolic programming, and inflammation. The Nrf2 pathway participates in anti-oxidative, cytoprotective, and anti-inflammatory activities. This prominent regulator, through pharmacologic activation, could provide a therapeutic strategy for the diseases to the etiology and pathogenesis of which NLRP3 inflammasome contributes. In this review, current knowledge on NLRP3 inflammasome activation and Nrf2 pathways is presented; the relationship between NLRP3 inflammasome signaling and Nrf2 pathway, as well as the pre/clinical use of Nrf2 activators against NLRP3 inflammasome activation in disorders of the central nervous system, are thoroughly described. Cumulative evidence points out therapeutic use of Nrf2 activators against NLRP3 inflammasome activation or diseases that NLRP3 inflammasome contributes to would be advantageous to prevent inflammatory conditions; however, the side effects of these molecules should be kept in mind before applying them to clinical practice.

Long non-coding RNA MEG3 promotes tumor necrosis factor-alpha induced oxidative stress and apoptosis in interstitial cells of cajal via targeting the microRNA-21 /I-kappa-B-kinase beta axis

Interstitial Cells of Cajal (ICC) plays a critical role in the peristaltic contractions of the gastrointestinal and urinary tract. The dysfunction and loss of ICC contributes to hypokinetic disease, such as gallstoneand ureteropelvic junction obstruction . In the present study, we identified the underlying driving molecular signals of oxidative stress and apoptosis in ICC. ICC was isolated from small intestine of Balb/c mice, and stimulated with tumor necrosis factor-alpha (TNF-α). MTT and flow cytometry were performed to assess cell viability, apoptosis, and the level of reactive oxygen species in ICC, respectively. The level of malondialdehyde, superoxide dismutase, and glutathione peroxidase in cells were measured to assess oxidative stress. The expression of inflammatory factors (interleukin, IL-1 and IL-6) and apoptosis-related proteins were detected by western blot. We observed that TNF-αinduced inflammation, oxidative stress and cell apoptosis in ICC. By using quantitative real-time PCR , we verified that the expression of long non-coding RNAMEG3 was elevated by TNF-α in ICC. Silencing MEG3 reversed inflammation, oxidative stress, and cell apoptosisin TNF-α-treated ICC. Subsequently, we confirmed that MEG3 sponged cytoprotective miR-21 to upregulate the expression of I-kappa-B-kinase beta (IKKB) and activate the nuclear factor kappa-B (NF-κB) pathway. Both miR-21 overexpression and IKKB knockdown reduced TNF-α-induced above symptoms in ICC. Taken together, we can conclude that MEG3 mediates inflammation, oxidative stress and apoptosis in TNF-α-treated ICC via the miR-21/IKKB-NF-κB axis. The study improves our understanding of the molecular mechanism of ICC reduction related diseases.

Long noncoding RNA Kcnq1ot1 prompts lipopolysaccharide-induced acute lung injury by microRNA-7a-5p/Rtn3 axis

Background

Long noncoding RNA (lncRNA)-regulated mechanism in acute lung injury (ALI) has attracted special interests in study researches. We planned to disclose whether KCNQ1 overlapping transcript 1 (Kcnq1ot1) is involved in ALI and its mechanism.

Methods

The lipopolysaccharide (LPS)-induced ALI model was established in mice. Kcnq1ot1, microRNA (miR)-7a-5p and Reticulon 3 (Rtn3) levels were measured in lung tissues of mice. The vector that changed Kcnq1ot1, miR-7a-5p and Rtn3 expression was injected into LPS-treated mice, and pathological damage, fibrosis, apoptosis and inflammatory response were subsequently examined in lung tissues. The relation between Kcnq1ot1 and miR-7a-5p, and that between miR-7a-5p and Rtn3 were identified.

Results

Kcnq1ot1 and Rtn3 expression increased while miR-7a-5p expression decreased in LPS-treated mice. Reduced Kcnq1ot1 or elevated miR-7a-5p alleviated pathological damage, fibrosis, apoptosis and inflammatory response in ALI mice, while overexpressed Rtn3 worsened ALI in mice. Downregulation of Rtn3 reversed the exacerbation of miR-7a-5p downregulation in ALI mice. Kcnq1ot1 competitively bound to miR-7a-5p and miR-7a-5p negatively mediated Rtn3 expression.

Conclusion

Our experiments evidence that silencing Kcnq1ot1 upregulates miR-7a-5p to suppress Rtn3 expression, thereby diminishing LPS-induced ALI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-022-00653-8.

Research Progress on the Inflammatory Effects of Long Non-coding RNA in Traumatic Brain Injury

Globally, traumatic brain injury (TBI) is an acute clinical event and an important cause of death and long-term disability. However, the underlying mechanism of the pathophysiological has not been fully elucidated and the lack of effective treatment a huge burden to individuals, families, and society. Several studies have shown that long non-coding RNAs (lncRNAs) might play a crucial role in TBI; they are abundant in the central nervous system (CNS) and participate in a variety of pathophysiological processes, including oxidative stress, inflammation, apoptosis, blood-brain barrier protection, angiogenesis, and neurogenesis. Some lncRNAs modulate multiple therapeutic targets after TBI, including inflammation, thus, these lncRNAs have tremendous therapeutic potential for TBI, as they are promising biomarkers for TBI diagnosis, treatment, and prognosis prediction. This review discusses the differential expression of different lncRNAs in brain tissue during TBI, which is likely related to the physiological and pathological processes involved in TBI. These findings may provide new targets for further scientific research on the molecular mechanisms of TBI and potential therapeutic interventions.

TI: NLRP3 Inflammasome-Dependent Pyroptosis in CNS Trauma: A Potential Therapeutic Target

Central nervous system (CNS) trauma, including traumatic brain injury (TBI) and traumatic spinal cord injury (SCI), is characterized by high morbidity, disability, and mortality. TBI and SCI have similar pathophysiological mechanisms and are often accompanied by serious inflammatory responses. Pyroptosis, an inflammation-dependent programmed cell death, is becoming a major problem in CNS post-traumatic injury. Notably, the pyrin domain containing 3 (NLRP3) inflammasome is a key protein in the pyroptosis signaling pathway. Therefore, underlying mechanism of the NLRP3 inflammasome in the development of CNS trauma has attracted much attention. In this review, we briefly summarize the molecular mechanisms of NLRP3 inflammasome in pyroptosis signaling pathway, including its prime and activation. Moreover, the dynamic expression pattern, and roles of the NLRP3 inflammasome in CNS post-traumatic injury are summarized. The therapeutic applications of NLRP3 inflammasome activation inhibitors are also discussed.

Long Non-coding RNA: Insight Into Mechanisms of Alzheimer's Disease

Alzheimer's disease (AD), a heterogeneous neurodegenerative disorder, is the most common cause of dementia accounting for an estimated 60–80% of cases. The pathogenesis of AD remains unclear, and no curative treatment is available so far. Increasing evidence has revealed a vital role of non-coding RNAs (ncRNAs), especially long non-coding RNAs (lncRNAs), in AD. LncRNAs contribute to the pathogenesis of AD via modulating amyloid production, Tau hyperphosphorylation, mitochondrial dysfunction, oxidative stress, synaptic impairment and neuroinflammation. This review describes the biological functions and mechanisms of lncRNAs in AD, indicating that lncRNAs may provide potential therapeutic targets for the diagnosis and treatment of AD.

Mechanism of M2 macrophage-derived extracellular vesicles carrying lncRNA MEG3 in inflammatory responses in ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory disease of the colon. M2 macrophages possess certain anti-inflammation activity. Accordingly, the current study set out to investigate the potential mechanism of M2 macrophage-derived extracellular vesicles (M2-EVs) in UC inflammation. Firstly, mouse peritoneal macrophages were induced to M2 phenotype, and M2-EVs were isolated. , the murine model of UC was established, and the length and weight of the colon, disease activity index (DAI), apoptosis, and inflammatory response of UC mice were measured. Young adult mouse colon (YAMC) cells were induced with the help of lipopolysaccharide. LncRNA maternally expressed 3 (LncRNA MEG3), miR-20b-5p, and cAMP responsive element binding protein 1 (CREB1) expression patterns were detected in UC models. In addition, we analyzed the binding relationship among MEG3, miR-20b-5p, and CREB1. UC mice presented with shortened colon length, lightened weight, increased DAI score, enhanced apoptosis, and significant inflammatory cell infiltration, while M2-EVs reversed these trends. In vitro, M2-EVs increased UC cell viability and reduced inflammation. Mechanistic experimentation revealed that M2-EVs transferred MEG3 into YAMC cells to up-regulate MEG3 expression and promote CREB1 transcription by competitively binding to miR-20b-5p. Moreover, up-regulation of MEG3 in M2-EVs enhanced the protective effect of M2-EVs on UC cells, while over-expression of miR-20b-5p attenuated the aforementioned protective effect of M2-EVs on UC mice and cells. Collectively, our findings revealed that M2-EVs carrying MEG3 enhanced UC cell viability and reduced inflammatory responses via the miR-20b-5p/CREB1 axis, thus alleviating UC inflammation.

LncRNA 4344 promotes NLRP3-related neuroinflammation and cognitive impairment by targeting miR-138-5p

OBJECTIVE

Cognitive impairment is a common neurological disease of which NLRP3-related neuroinflammation has been demonstrated to be an essential mediator. Previous studies have indicated that long non-coding RNAs (lncRNAs) are critical for the development of neurological disorders. However, the roles and functions of lncRNA 4344 in neuroinflammation during cognitive impairment are unknown and need to be further elucidated.

METHODS

Lipopolysaccharide (LPS)-induced rat cognitive impairment and rat microglia (RM) cell inflammation models were established in vitro and in vivo. The Morris water maze test was used to evaluate the cognitive behavior of the rats. Gene expression was assessed using real-time quantitative polymerase chain reaction, and protein levels using enzyme-linked immunosorbent assay, or western blot analysis. The targeting relationship between lncRNA 4344, miR-138-5p, and NLRP3 was identified using bioinformatics analysis and a dual-luciferase reporter gene assay. Hematoxylin-Eosin and Nissl stainings, terminal deoxynucleotidyl transferase dUTP nick end labeling, or immunofluorescence staining assays were performed to detect pathological changes, neuronal apoptosis, or positive cells in hippocampal tissues, respectively.

RESULTS

The expression levels of lncRNA 4344 and NLRP3 were upregulated in the hippocampal tissues of LPS-treated rats and RM cells, and showed a strong positive correlation between each other. LncRNA 4344 overexpression further enhanced the expression of NLRP3 and its downstream genes (caspase-1, IL-1β, and IL-18), as well as neuronal apoptosis in LPS-stimulated RM cells, whereas lncRNA 4344 silencing attenuated the inflammatory injuries. Moreover, miR-138-5p was the direct target of lncRNA 4344 and was downregulated in the RM cell inflammation model. We also found that miR-138-5p directly reduced the expression of NLRP3 and its downstream genes. Subsequently, the results of the animal experiments showed that the lncRNA 4344/miR-138-5p/NLRP3 axis plays an essential role in regulating the cognitive behavior, pathological changes and apoptosis of hippocampal neurons, expression of inflammation-related factors (NLRP3, caspase-1, IL-1β, and IL-18), and microglial activation in LPS-induced cognitive impairment rats.

CONCLUSION

Our results demonstrated for the first time that lncRNA 4344 regulates NLRP3-related neuroinflammation and cognitive impairment by targeting miR-138-5p, providing a possible target for the treatment of diseases characterized by a cognitive deficit.

Long Non-coding RNAs and Circular RNAs: Insights Into Microglia and Astrocyte Mediated Neurological Diseases

Microglia and astrocytes maintain tissue homeostasis in the nervous system. Both microglia and astrocytes have pro-inflammatory phenotype and anti-inflammatory phenotype. Activated microglia and activated astrocytes can contribute to several neurological diseases. Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), two groups of non-coding RNAs (ncRNAs), can function as competing endogenous RNAs (ceRNAs) to impair the microRNA (miRNA) inhibition on targeted messenger RNAs (mRNAs). LncRNAs and circRNAs are involved in various neurological disorders. In this review, we summarized that lncRNAs and circRNAs participate in microglia dysfunction, astrocyte dysfunction, neuron damage, and inflammation. Thereby, lncRNAs and circRNAs can positively or negatively regulate neurological diseases, including spinal cord injury (SCI), traumatic brain injury (TBI), ischemia-reperfusion injury (IRI), stroke, neuropathic pain, epilepsy, Parkinson’s disease (PD), multiple sclerosis (MS), and Alzheimer’s disease (AD). Besides, we also found a lncRNA/circRNA-miRNA-mRNA regulatory network in microglia and astrocyte mediated neurological diseases. Through this review, we hope to cast light on the regulatory mechanisms of lncRNAs and circRNAs in microglia and astrocyte mediated neurological diseases and provide new insights for neurological disease treatment.

lncRNA MEG3 aggravated neuropathic pain and astrocyte overaction through mediating miR-130a-5p/CXCL12/CXCR4 axis

OBJECTIVE

Long non-coding RNAs (lncRNAs) exert a critical function in mediating neuropathic pain (NP). MEG3, a novel lncRNA, contributes to astrocyte activation and inflammation. However, its role in NP remains unclear.

METHODS

The chronic constriction injury (CCI) method was employed to construct an NP rat model. Astrocyte activation was induced by lipopolysaccharide (LPS). The profiles of MEG3, microRNA (miR)-130a-5p, CXC motif chemokine receptor 12 (CXCL12)/CXC motif chemokine receptor 4 (CXCR4), and the Rac1/NF-κB pathway in CCI rats' spinal cord tissues and astrocytes were monitored by reverse transcription-quantitative PCR (RT-qPCR) and western blot (WB). Pain scores of CCI rats were assessed. Enzyme-linked immunosorbent assay (ELISA) was adopted to monitor neuroinflammation alteration. The glial fibrillary acidic protein (GFAP)-labeled astrocytes were tested by immunohistochemistry (IHC). Bioinformatics, dual-luciferase reporter assay and RNA immunoprecipitation (RIP) were utilized to verify the molecular mechanism between MEG3 and miR-130a-3p.

RESULTS

MEG3, CXCL12 and CXCR4 were overexpressed and miR-130a-5p was knocked down in CCI rats and LPS-induced astrocytes. Up-regulating MEG3 aggravated NP, enhanced inflammatory cytokines interleukin-1β (IL-1β), tumor necrosis factor (TNF)-α, and interleukin-6 (IL-6) expression and release in CCI rats and LPS-induced astrocytes. Up-regulating miR-130-5p repressed LPS-induced inflammation in astrocytes. AS verified by the dual-luciferase reporter assay and RIP assay, MEG3 sponged miR-130a-5p as a competitive endogenous RNA (ceRNA). What's more, miR-130a-5p up-regulation weakened the MEG3-induced proinflammatory effects on LPS-induced astrocytes.

CONCLUSIONS

MEG3 aggravates NP and astrocyte activation via the miR-130a-5p/CXCL12/CXCR4 axis, which is a potential therapeutic target for NP.

Upregulated expression of long non-coding RNA MEG3 serves as a prognostic biomarker in severe pneumonia children and its regulatory mechanism

Severe pneumonia is a high-mortality disorder in children. The expression and underlying effects of lncRNA maternally expressed 3 (MEG3) were detected. The relationships between MEG3 and other parameters were reported by Pearson correlation. The prognostic importance of MEG3 was assessed by Kaplan-Meier (K-M) curve and COX analysis and its diagnostic potential was uncovered by the receiver operating characteristic (ROC) curve. Luciferase activity assay was performed to demonstrate the target gene of MEG3. Elevated expression of MEG3 and reduced microRNA-29 c (miR-29 c) were evaluated in severe pneumonia children, and a negative relationship between MEG3 and miR-29 c was propounded. MEG3 might function as an independent prognostic indicator. The diagnostic efficiency of MEG3 was also indicated for severe pneumonia children. In MRC-5 cell models and MH-S cell models, lipopolysaccharide (LPS) contributed to the increased expression of MEG3. Interference of MEG3 restricted the upregulation of MEG3 triggered by LPS. Silenced MEG3 protected MRC-5 and MH-S cells against damages managed by LPS on cell apoptosis, viability, and inflammation. MiR-29 c was a ceRNA of MEG3 and the absence of MEG3 abrogated the decreased expression of miR-29 c caused by LPS. Overall, the increased expression of MEG3 and the reduced levels of miR-29 c were identified in severe pneumonia. Prognostic and diagnostic significances of MEG3 provided a novel perspective for severe pneumonia. Disruption of MEG3 alleviated cell injury and inflammation as characterized by high LPS by binding miR-29 c.

Non-coding RNAs: The key regulators in NLRP3 inflammasome-mediated inflammatory diseases

Inflammasomes are multiprotein complexes responding to various microbes and endogenous danger signals, contributing to initiating the innate protective response of inflammatory diseases. NLRP3 inflammasome is a crucial regulator of pro-inflammatory cytokines (IL-1β and IL-18) production through activating caspase-1. Non-coding RNAs (ncRNAs) are a class of RNA transcripts lacking the ability to encode peptides or proteins. Its dysregulation leads to the development and progression of inflammation in diseases. Recently, accumulating evidence has indicated that NLRP3 inflammasome activation could be modulated by ncRNAs (lncRNAs, miRNAs, and circRNAs) in a variety of inflammatory diseases. This review focuses on the substantial role and function of ncRNAs in the NLRP3 inflammasome activation, providing novel insight for the future therapeutic approach of inflammatory diseases.