Downregulated lncRNA CRNDE contributes to the enhancement of nerve repair after traumatic brain injury in rats

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.

Therapeutic effect of thymoquinone on brain damage caused by nonylphenol exposure in rats

Nonylphenol (NP), causes various harmful effects such as cognitive impairment and neurotoxicity. Thymoquinone (TQ), has antioxidant, anti-inflammatory, and neuroprotective properties. In this study, our aim is to investigate the effects of TQ on the brain damage caused by NP. Corn oil was applied to the control group. NP (100 mg/kg/day) was administered to the NP and NP + TQ groups for 21 days. TQ (5 mg/kg/day) was administered to the NP + TQ and TQ groups for 7 after 21 days. At the end of the experiment, the new object recognition test was applied to the rats and the rats were killed and their brain tissues were removed. Sections taken from brain tissues were stained with hematoxylin-eosin for histopathological evaluation. In addition, neuronal nuclei (NeuN), glial fibrillary acidic protein (GFAP), Cas-3, and nerve growth factor (NGF) immunoreactivities were evaluated in brain tissue sections. In addition, malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) activities were determined. Comet assay was applied to determine DNA damage in cells. The results of our study showed that NP, caused behavioral disorders and damage to the cerebral cortex in rats. This damage in the form of neuron degeneration seen in the cortex was associated with apoptosis involving Cas-3 activation, increased DNA damage, and free oxygen radicals. NP, SOD, and CAT caused a decrease in enzyme activities. In addition, the cellular protein NeuN was decreased, astrocytosis-associated GFAP was increased, and growth factor NGF was decreased. When all our evaluations are taken together, treatment with TQ showed an ameliorative effect on the behavioral impairment and brain damage caused by NP exposure.

LncRNA Kcnq1ot1relieves neuropathic pain through downregulation of Myd88

BACKGROUND

Long non-coding RNAs (lncRNAs) have already been documented to become the therapeutic targets for neuropathic pain. Here, this work focused on exploring the specific mechanism underlying Kcnq1 overlapping transcript 1 (kcnq1ot1) in neuropathic pain.

METHODS

Sciatic nerve chronic constriction injury (CCI) in vivo and LPS-stimulated microglia BV2 cell injury in vitro were adopted to construct neuropathic pain models. Expressions of kcnq1ot1, MyD88, and microglia activation marker Iba-1 were measured. In this study, we carried out fluorescence in-situ Hybridization (FISH) and immunofluorescence for examining Kcnq1ot1 localization within microglial cells in mouse spinal dorsal horn. Subsequently, we evaluated binding between Kcnq1ot1 and Myd88, together with the expressions of IL-1β, IL-6, TNF-α, and Myd88 ubiquitination.

RESULTS

Kcnq1ot1 levels decreased within CCI mice and LPS-induced BV2 cells. According to the results of FISH and immunofluorescence, Kcnq1ot1 is located in microglia. Overexpression of Kcnq1ot1 suppressed Iba-1, IL-1β, IL-6 together with TNF-α expression. RNA pull-down and RIP assay confirmed that Kcnq1ot1 bound to Myd88. In addition, Kcnq1ot1 overexpression promoted the degradation, enhanced the ubiquitination, and reduced protein level of Myd88. Overexpression of Myd88 eliminated the effects of Kcnq1ot1 overexpression on Iba-1level and production of pro-inflammatory cytokines. Further in vivo results revealed that increased Kcnq1ot1 level alleviated neuropathic pain and myelinated nerve fiber injury of CCI mice.

CONCLUSION

Kcnq1ot1 downregulated Myd88 protein expression by binding to Myd88 and promoting its ubiquitination, which in turn suppressed microglia activation, pro-inflammatory cytokine production, and relieved neuropathic pain.

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.

SNHG1 alleviates the oxidative stress and inflammatory response in traumatic brain injury through regulating miR-377-3p/DUSP1 axis

OBJECTIVES

To investigate the role of short nucleolar RNA host gene 1 (SNHG1) in regulating inflammation and brain injury in traumatic brain injury (TBI).

METHODS

The Feeney's free-falling method was used to induce moderate TBI model in mice. Lipopolysaccharide (LPS) was employed to construct the microglia in vitro. Reverse transcription-PCR (RT-PCR) was conducted to monitor expression of SNHG1, microRNAs (miR)-377-3p, oxidative and inflammatory factors. TdT-mediated dUTP nick end labeling and immunohistochemistry were adopted to determine neuronal cell apoptosis. Flow cytometry was conducted to measure apoptosis. Moreover, Bax, Bcl2, Caspase3, dual-specific phosphatase-1 (DUSP1)/mitogen-activated protein kinase/NF-KB were tested by western blot. Furthermore, bioinformatics, dual-luciferase assay and RNA-binding protein immunoprecipitation experiment were implemented to verify the targeting relationship among SNHG1, miR-377-3p and DUSP1.

RESULTS

SNHG1 was knocked down, while miR-377-3p was overexpressed in TBI mice and lipopolysaccharide-induced microglia. Meanwhile, overexpressing SNHG1 reduced neuronal damage and weakened the oxidative stress and inflammation in TBI on matter in vivo or in vitro. Additionally, overexpressing SNHG1 attenuated miR-377-3p-mediated inflammatory factors, oxidative stress and neuronal damage. Moreover, miR-377-3p was the target of SNHG1 and DUSP1.

CONCLUSIONS

This study provides a better understanding of the SNHG1/miR-377-3p/DUSP1 axis in regulating the development of TBI, which is helpful to formulate a treatment plan for TBI.

Role of autophagy and transcriptome regulation in acute brain injury

Autophagy is an evolutionarily conserved intracellular system that routes distinct cytoplasmic cargo to lysosomes for degradation and recycling. Accumulating evidence highlight the mechanisms of autophagy, such as clearance of proteins, carbohydrates, lipids and damaged organelles. The critical role of autophagy in selective degradation of the transcriptome is still emerging and could shape the total proteome of the cell, and thus can regulate the homeostasis under stressful conditions. Unregulated autophagy that potentiates secondary brain damage is a key pathological features of acute CNS injuries such as stroke and traumatic brain injury. This review discussed the mutual modulation of autophagy and RNA and its significance in mediating the functional consequences of acute CNS injuries.

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.

Coding and long non-coding gene expression changes in the CNS traumatic injuries

Traumatic brain injury (TBI) and spinal cord injury (SCI) are two main central nervous system (CNS) traumas, caused by external physical insults. Both injuries have devastating effects on the quality of life, and there is no effective therapy at present. Notably, gene expression profiling using bulk RNA sequencing (RNA-Seq) and single-cell RNA-Seq (scRNA-Seq) have revealed significant changes in many coding and non-coding genes, as well as important pathways in SCI and TBI. Particularly, recent studies have revealed that long non-coding RNAs (lncRNAs) with lengths greater than 200 nucleotides and without protein-coding potential have tissue- and cell type-specific expression pattern and play critical roles in CNS injury by gain- and loss-of-function approaches. LncRNAs have been shown to regulate protein-coding genes or microRNAs (miRNAs) directly or indirectly, participating in processes including inflammation, glial activation, cell apoptosis, and vasculature events. Therefore, lncRNAs could serve as potential targets for the diagnosis, treatment, and prognosis of SCI and TBI. In this review, we highlight the recent progress in transcriptome studies of SCI and TBI and insights into molecular mechanisms.

Expression characteristics of long noncoding RNA and messenger RNA in human traumatic brain injury

OBJECTIVES

The role of long noncoding RNAs has attracted significant attention in diseases. However, their expression characteristics in human traumatic brain injury are unclear.

METHODS

The brain contusion tissues and tissues adjacent to the brain contusion from 6 server traumatic brain injury patients were used to analyze differential expression signatures of long noncoding RNAs and mRNAs via full-length transcriptome sequencing, Gene Ontology analysis, Kyoto Encyclopedia of Genes and Genomes pathway analysis and establishment of a long noncoding RNA/mRNA coexpression network.

RESULTS

We identified 1720 long noncoding RNAs and 1632 mRNAs differential expression. Microarray analysis showed that 874 long noncoding RNAs and 1405 mRNAs were upregulated, 846 long noncoding RNAs and 227 mRNAs were downregulated. Subsequently, we used Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses to reveal signaling pathways that were associated with target genes. Then, a long noncoding RNA/mRNA coexpression network was generated, which showed an absolute correlation coefficient value >0.99 for 559 long noncoding RNA-mRNA pairs. Finally, we comprehensive analyzed long noncoding RNA/mRNA coexpression network and Kyoto Encyclopedia of Genes and Genomes pathway and found the top five pairs of long noncoding RNA/ mRNA. Accordingly, we identified that long noncoding RNA tubulin beta 6 class V/nuclear factor E2-related factor 2 was most closely related to the pathological process after traumatic brain injury.

CONCLUSIONS

Our results indicated that the expression profiles of long noncoding RNAs and mRNAs were different after traumatic brain injury, providing new insight regarding long noncoding RNAs in human traumatic brain injury.

Autophagy and apoptosis cascade: which is more prominent in neuronal death?

Autophagy and apoptosis are two crucial self-destructive processes that maintain cellular homeostasis, which are characterized by their morphology and regulated through signal transduction mechanisms. These pathways determine the fate of cellular organelle and protein involved in human health and disease such as neurodegeneration, cancer, and cardiovascular disease. Cell death pathways share common molecular mechanisms, such as mitochondrial dysfunction, oxidative stress, calcium ion concentration, reactive oxygen species, and endoplasmic reticulum stress. Some key signaling molecules such as p53 and VEGF mediated angiogenic pathway exhibit cellular and molecular responses resulting in the triggering of apoptotic and autophagic pathways. Herein, based on previous studies, we describe the intricate relation between cell death pathways through their common genes and the role of various stress-causing agents. Further, extensive research on autophagy and apoptotic machinery excavates the implementation of selective biomarkers, for instance, mTOR, Bcl-2, BH3 family members, caspases, AMPK, PI3K/Akt/GSK3β, and p38/JNK/MAPK, in the pathogenesis and progression of neurodegenerative diseases. This molecular phenomenon will lead to the discovery of possible therapeutic biomolecules as a pharmacological intervention that are involved in the modulation of apoptosis and autophagy pathways. Moreover, we describe the potential role of micro-RNAs, long non-coding RNAs, and biomolecules as therapeutic agents that regulate cell death machinery to treat neurodegenerative diseases. Mounting evidence demonstrated that under stress conditions, such as calcium efflux, endoplasmic reticulum stress, the ubiquitin-proteasome system, and oxidative stress intermediate molecules, namely p53 and VEGF, activate and cause cell death. Further, activation of p53 and VEGF cause alteration in gene expression and dysregulated signaling pathways through the involvement of signaling molecules, namely mTOR, Bcl-2, BH3, AMPK, MAPK, JNK, and PI3K/Akt, and caspases. Alteration in gene expression and signaling cascades cause neurotoxicity and misfolded protein aggregates, which are characteristics features of neurodegenerative diseases. Excessive neurotoxicity and misfolded protein aggregates lead to neuronal cell death by activating death pathways like autophagy and apoptosis. However, autophagy has a dual role in the apoptosis pathways, i.e., activation and inhibition of the apoptosis signaling. Further, micro-RNAs and LncRNAs act as pharmacological regulators of autophagy and apoptosis cascade, whereas, natural compounds and chemical compounds act as pharmacological inhibitors that rescue neuronal cell death through inhibition of apoptosis and autophagic cell death.

Identification of novel biomarkers for intracerebral hemorrhage via long noncoding RNA-associated competing endogenous RNA network

Intracerebral hemorrhage (ICH) is a leading cause of death and disability worldwide. This study aimed to examine the involvement of long non-coding RNAs (lncRNAs), a group of non-coding transcripts, in ICH as potential biomarkers. An expression profile of patients with ICH using four contralateral grey matter controls (GM) and four contralateral white matter controls (WM) was downloaded from the Gene Expression Omnibus (GEO) database. Co-expressed lncRNAs and mRNAs were selected to create competing endogenous RNA (ceRNA) networks. Key lncRNAs were identified in ceRNA networks, which were validated through Real-time qPCR (RT-qPCR) with peripheral blood samples from patients with ICH. A total of 49 differentially expressed lncRNAs were discovered in different brain regions. The ceRNA network in GM included 9 lncRNAs, 40 mRNAs, and 20 microRNAs (miRNAs), while the one in WM covered 6 lncRNAs, 25 mRNAs, and 14 miRNAs. Six hub lncRNAs were observed and RT-qPCR results showed that LY86-AS1, DLX6-AS1, RRN3P2, and CRNDE were down-regulated, while HCP5 and MIAT were up-regulated in patients with ICH. Receiver Operating Characteristic (ROC) assessments demonstrated the diagnostic value of these lncRNAs. Our findings highlight the potential roles of lncRNA in ICH pathogenesis. Moreover, the hub lncRNAs discovered here might become novel biomarkers and promising targets for ICH drug development.

LncRNA CRNDE Exacerbates IgA Nephropathy Progression by Promoting NLRP3 Inflammasome Activation in Macrophages

BACKGROUND

Activation of NLRP3 inflammasome in macrophages contributes greatly to IgA nephropathy (IgAN) progression. This study intended to investigate the underlying mechanism of NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation in the development of IgAN.

METHODS

We examined the expression levels of colorectal neoplasia differentially expressed (CRNDE), NLRP3 inflammasome-related proteins in peripheral blood mononuclear cells (PBMCs) and J774A.1 cells and detected inflammatory cytokine levels in the serum of IgAN patients and cell supernatants of in vitro IgAN model. RNA pull-down and RNA immunoprecipitation (RIP) experiments were conducted to evaluate the interaction between CRNDE and NLRP3. Then, the ubiquitin level of NLRP3 and its binding ability to TRIM family member 31 (TRIM31) were determined.

RESULTS

Compared with the control group, the expressions of CRNDE and NLRP3 inflammasome-related proteins in PBMCs and J774A.1 cells and levels of IL-1β, TNF-α and IL-12 in serum of IgAN patients and cell supernatants of IgA-IC-induced J774A.1 cells were all increased. CRNDE silencing down-regulated NLRP3 inflammasome-related proteins and the levels of IL-1β, TNF-α and IL-12 in cell supernatants, while NLRP3 overexpression reversed these effects. Additionally, CRNDE could interact with NLRP3 and promote NLRP3 expression. Furthermore, inhibition of CRNDE reduced NLRP3 protein level and promoted TRIM31-mediated NLRP3 ubiquitination and degradation.

CONCLUSION

CRNDE exacerbates IgA nephropathy progression through restraining ubiquitination and degradation of NLRP3 and facilitating NLRP3 inflammasome activation in macrophages.

LncRNA CRNDE exacerbates neuropathic pain in chronic constriction injury-induced(CCI) rats through regulating miR-146a-5p/WNT5A pathway

Neuropathic pain (NP) originating from a dysfunction in the nervous system is often intractable and chronic. Many studies have implicated long noncoding RNAs (lncRNAs) in the physiological and pathological development of NP. The lncRNA colorectal neoplasia differentially expressed gene (CRNDE) has been shown to mediate NP progression. However, further investigations are needed to gain deeper understanding of the specific mechanisms governing CRNDE in NP etiopathology. In this study, we successfully used chronic constrictive injury (CCI)-induced rats to establish an NP model with intrathecal injection, and confirmed the upregulation of CRNDE in CCI-induced rats. Moreover, silencing of CRNDE relieved mechanical allodynia, thermal hyperalgesia, and neuroinflammation in the NP model. Bioinformatics analysis predicted that miR-146a-5p binds to CRNDE. Our findings validated that miR-146a-5p was a target of CRNDE and that the expression of miR-146a-5p was decreased in CCI rats. Furthermore, miR-151A-3p was found to exert a negative regulatory effect on WNT5A. In addition, knockdown of WNT5A alleviated the pain-related behavior and inflammatory response of NP in vivo. Finally, we demonstrated that CRNDE contributed to the progression of CCI-induced NP via competitive binding to miR-146a-5p to upregulate WNT5A. The present study offers novel insights that may be translated into improved therapies for NP.

HOXA11-AS aggravates microglia-induced neuroinflammation after traumatic brain injury

Long noncoding RNAs (lncRNAs) participate in many pathophysiological processes after traumatic brain injury by mediating neuroinflammation and apoptosis. Homeobox A11 antisense RNA (HOXA11-AS) is a member of the lncRNA family that has been reported to participate in many inflammatory reactions; however, its role in traumatic brain injury remains unclear. In this study, we established rat models of traumatic brain injury using a weight-drop hitting device and injected LV-HOXA11-AS into the right lateral ventricle 2 weeks before modeling. The results revealed that overexpression of HOXA11-AS aggravated neurological deficits in traumatic brain injury rats, increased brain edema and apoptosis, promoted the secretion of proinflammatory factors interleukin-1β, interleukin-6, and tumor necrosis factor α, and promoted the activation of astrocytes and microglia. Microglia were treated with 100 ng/mL lipopolysaccharide for 24 hours to establish in vitro cell models, and then transfected with pcDNA-HOXA11-AS, miR-124-3p mimic, or sh-MDK. The results revealed that HOXA11-AS inhibited miR-124-3p expression and boosted MDK expression and TLR4-nuclear factor-κB pathway activation. Furthermore, lipopolysaccharide enhanced potent microglia-induced inflammatory responses in astrocytes. Forced overexpression of miR-124-3p or downregulating MDK repressed microglial activation and the inflammatory response of astrocytes. However, the miR-124-3p-mediated anti-inflammatory effects were reversed by HOXA11-AS. These findings suggest that HOXA11-AS can aggravate neuroinflammation after traumatic brain injury by modulating the miR-124-3p-MDK axis. This study was approved by the Animal Protection and Use Committee of Southwest Medical University (approval No. SMU-2019-042) on February 4, 2019.

HOTTIP downregulation reduces neuronal damage and microglial activation in Parkinson's disease cell and mouse models

HOXA transcript at the distal tip (HOTTIP), a newly identified long noncoding RNA, has been shown to exhibit anti-inflammatory effects and inhibit oxygen-glucose deprivation-induced neuronal apoptosis. However, its role in Parkinson’s disease (PD) remains unclear. 1-Methyl-4-phenylpyridium (MPP⁺) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were used to establish PD models in SH-SY5Y and BV2 cells and in C57BL/6 male mice, respectively. In vitro, after HOTTIP knockdown by sh-HOTTIP transfection, HOTTIP and FOXO1 overexpression promoted SH-SY5Y apoptosis, BV2 microglial activation, proinflammatory cytokine expression, and nuclear factor kappa-B and NACHT, LRR and PYD domains-containing protein 3 inflammasome activation. Overexpression of miR-615-3p inhibited MPP⁺-induced neuronal apoptosis and microglial inflammation and ameliorated HOTTIP- and FOXO1-mediated nerve injury and inflammation. In vivo, HOTTIP knockdown alleviated motor dysfunction in PD mice and reduced neuronal apoptosis and microglial activation in the substantia nigra. These findings suggest that inhibition of HOTTIP mitigates neuronal apoptosis and microglial activation in PD models by modulating miR-615-3p/FOXO1. This study was approved by the Ethics Review Committee of the Affiliated Hospital of Qingdao University, China (approval No. UDX-2018-042) in June 2018.

Long non-coding RNAs mediate cerebral vascular pathologies after CNS injuries

Central nervous system (CNS) injuries are one of the leading causes of morbidity and mortality worldwide, accompanied with high medical costs and a decreased quality of life. Brain vascular disorders are involved in the pathological processes of CNS injuries and might play key roles for their recovery and prognosis. Recently, increasing evidence has shown that long non-coding RNAs (lncRNAs), which comprise a very heterogeneous group of non-protein-coding RNAs greater than 200 nucleotides, have emerged as functional mediators in the regulation of vascular homeostasis under pathophysiological conditions. Remarkably, lncRNAs can regulate gene transcription and translation, thus interfering with gene expression and signaling pathways by different mechanisms. Hence, a deeper insight into the function and regulatory mechanisms of lncRNAs following CNS injury, especially cerebrovascular-related lncRNAs, could help in establishing potential therapeutic strategies to improve or inhibit neurological disorders. In this review, we highlight recent advancements in understanding of the role of lncRNAs and their application in mediating cerebrovascular pathologies after CNS injury.

Discoveries of the specific expression of lncRNAs and mRNAs in hippocampus of rats after traumatic brain injury

Objects

Explore the relationship between the neural function deficit and the changes of lncRNA and mRNA in hippocampus after traumatic brain injury (TBI) in rats.

Methods

Twenty male rats weighted 200-240 grams were randomly divided into sham group and TBI group. Neurologic severity score (NSS) was performed after operation, and the hippocampus of rats was collected for long non-coding RNAs (lncRNAs), mRNAs microarray detection, real-time quantitative PCR Detecting System (Q-PCR), western blot (WB) detection, and serum biochemical detection.

Results

The NSS score of the TBI group was significantly higher than the sham group. Compared with the sham group, 270 lncRNAs changed in the TBI group, of which 224 were up-regulated and 46 were down-regulated. Among up-regulated lncRNAs, mRNAs were distributed in upstream of 22 lncRNAs, downstream of 17 lncRNAs, overlapping regions of 48 lncRNAs, and antisense chains of 21 lncRNAs. Among down-regulated lncRNAs, mRNAs were distributed in upstream of 6 lncRNAs, downstream of 3 lncRNAs, overlapping regions of 10 lncRNAs, and antisense chains of 8 lncRNAs. Compared with the sham group, 1054 mRNA changed in the TBI group, of which 921 mRNA were up-regulated and 133 mRNA were down-regulated. The expression changes of ENSRNOT000063054, ENSRNOT000052790, ENSRNOT00000054410, ENSRNOT000063242, and ENSRNOT000069411 IncRNA regulate the expression of Top2a, RT1-CE11, Papss2, Stk32a, and Grid2 gene.

Conclusion

The present study detected the differential expression of lncRNAs and mRNAs in hippocampi of rats subjected to TBI, and discussed their relation, primarily.

New Insight of Circular RNAs' Roles in Central Nervous System Post-Traumatic Injury

The central nervous system (CNS) post-traumatic injury can cause severe nerve damage with devastating consequences. However, its pathophysiological mechanisms remain vague. There is still an urgent need for more effective treatments. Circular RNAs (circRNAs) are non-coding RNAs that can form covalently closed RNA circles. Through second-generation sequencing technology, microarray analysis, bioinformatics, and other technologies, recent studies have shown that a number of circRNAs are differentially expressed after traumatic brain injury (TBI) or spinal cord injury (SCI). These circRNAs play important roles in the proliferation, inflammation, and apoptosis in CNS post-traumatic injury. In this review, we summarize the expression and functions of circRNAs in CNS in recent studies, as well as the circRNA–miRNA–mRNA interaction networks. The potential clinical value of circRNAs as a therapeutic target is also discussed.

Downregulation of lncRNA KCNQ1OT1 relieves traumatic brain injury induced neurological deficits via promoting "M2" microglia polarization

BACKGROUND

Microglia-induced neuroinflammation is one of the main characteristics of traumatic brain injury (TBI). Presently, we aim to investigate the role of long non-coding RNA (lncRNA) KCNQ1 overlapping transcript 1 (KCNQ1OT1) in TBI-induced neurological deficits and the related mechanism.

METHODS

An in-vivo TBI model was established in mice, and in-vitro experiments were carried out on BV2 microglia. Then the neurological functions, microglial activation, inflammatory cytokines, and proteins were detected.

RESULTS

Our data indicated that KCNQ1OT1 was markedly overexpressed in the cerebral tissues of TBI mice, accompanied by a higher level of the cytokines (including IL-1β, IL-6, and TNFα). However, knocking down KCNQ1OT1 relieved neurological deficits, neuron loss, and blood-brain barrier damage. Besides, overexpressing miR-873-5p enhanced the "M2″ polarization of microglia by repressing the TRAF6-mediated p38 and NF-κB pathways. In contrast, downregulating KCNQ1OT1 repressed microglial neuroinflammation by attenuating the "M1″ polarization of microglia and promoting "M2″ polarization of microglia, and inactivating the p38 and NF-κB pathway.

CONCLUSIONS

Mechanistically, KCNQ1OT1 functioned as a competitive endogenous RNA (ceRNA) by sponging miR-873-5p, which targeted the 3' untranslated region (UTR) of TRAF6. Overall, our data confirmed that downregulating lncRNA KCNQ1OT1 exerted neuroprotective effects on TBI mice by modulating the miR-873-5p-TRAF6-p38/NF-κB axis.

The Expanding Regulatory Mechanisms and Cellular Functions of Long Non-coding RNAs (lncRNAs) in Neuroinflammation

LncRNAs have emerged as important regulatory molecules in biological processes. They serve as regulators of gene expression pathways through interactions with proteins, RNA, and DNA. LncRNA expression is altered in several diseases of the central nervous system (CNS), such as neurodegenerative disorders, stroke, trauma, and infection. More recently, it has become clear that lncRNAs contribute to regulating both pro-inflammatory and anti-inflammatory pathways in the CNS. In this review, we discuss the molecular pathways involved in the expression of lncRNAs, their role and mechanism of action during gene regulation, cellular functions, and use of lncRNAs as therapeutic targets during neuroinflammation in CNS disorders.

Silencing of long non-coding RNA CRNDE promotes autophagy and alleviates neonatal hypoxic-ischemic brain damage in rats

Hypoxic-ischemic (HI) brain damage (HIBD) leads to high neonatal mortality and severe neurologic morbidity. Autophagy is involved in the pathogenesis of HIBD. This study aims to investigate the effect of long non-coding RNA colorectal neoplasia differentially expressed (CRNDE) on HIBD and to validate whether autophagy is involved in this process. A HIBD model in rat pups and a HI model in rat primary cerebrocortical neurons were established. Autophagy was evaluated by western blot. The HIBD in rats was evaluated by hematoxylin and eosin staining, TUNEL staining, triphenyl tetrazolium chloride staining, and morris water maze test. The HI injury in vitro was evaluated by determining cell viability and apoptosis. The results showed that CRNDE expression was time-dependently increased in the brain after HIBD. Administration with CRNDE shRNA-expressing lentiviruses alleviated pathological injury and apoptosis in rat hippocampus, decreased infarct volume, and improved behavior performance of rats subjected to HIBD. Furthermore, CRNDE silencing promoted cell viability and inhibited cell apoptosis in neurons exposed to HI. Moreover, CRNDE silencing promoted autophagy and the autophagy inhibitor 3-methyladenine counteracted the neuroprotective effect of CRNDE silencing on HI-induced neuronal injury both in vivo and in vitro. Collectively, CRNDE silencing alleviates HIBD, at least partially, through promoting autophagy.

Long non-coding RNA CRNDE deteriorates intrauterine infection-induced neonatal brain injury

BACKGROUND

This study aimed to test the hypothesis that long non-coding RNA (lncRNA) colorectal neoplasia differentially expressed (CRNDE) could exacerbate brain injury caused by intrauterine infection in neonatal rats.

METHODS

Intrauterine infection was induced in pregnant rats by lipopolysaccharide (LPS). After delivery, newborn rats with brain injury caused by intrauterine infection were randomly divided into control, control shRNA, and CRNDE shRNA groups. CRNDE expression in serum and amniotic fluid of pregnant rats and neonatal brain tissues were determined by quantitative real-time PCR (qRT-PCR). Morris water maze (MWM) task was used to test the spatial learning and memory ability. Histological examination and apoptosis detection were performed by hematoxylin and eosin (H&E) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, respectively. Immunohistochemistry was conducted to evaluate the activation of astrocytes and microglia.

RESULTS

LncRNA CRNDE was highly expressed in serum and amniotic fluid of maternal rats and in brain tissues of offspring rats. Furthermore, shRNA-mediated CRNDE downregulation could rescue the spatial learning and memory ability, improve brain histopathological changes and cell death, and inhibit the activation of astrocytes and microglia caused by LPS.

CONCLUSION

CRNDE silencing possessed a cerebral protective effect in neonatal rats with brain injury caused by interauterine infection.

Long Noncoding RNAs in Development and Regeneration of the Neural Lineage

Long noncoding RNAs (lncRNAs) are gathering increasing attention toward their roles in different biological systems. In mammals, the richest repertoires of lncRNAs are expressed in the brain and in the testis, and the diversity of lncRNAs in the nervous system is thought to be related to the diversity and the complexity of its cell types. Supporting this notion, many lncRNAs are differentially expressed between different regions of the brain or in particular cell types, and many lncRNAs are dynamically expressed during embryonic or postnatal neurogenesis. Less is known about the functions of these genes, if any, but they are increasingly implicated in diverse processes in health and disease. Here, we review the current knowledge about the roles and importance of lncRNAs in the central and peripheral nervous systems and discuss the specific niches within gene regulatory networks that might be preferentially occupied by lncRNAs.

Long non-coding RNA Snhg3 protects against hypoxia/ischemia-induced neonatal brain injury

Hypoxic-ischemic brain damage (HIBD) is a major cause of morbidity and mortality in the preterm and term infant. However, the precise mechanism of HIBD remains largely elusive. As a newly discovered long non-coding RNA, small nucleolar RNA host gene 3 (Snhg3) has shown its important roles in cell apoptosis, proliferation, and disease development. In this study, we determined the role of Snhg3 in the pathogenesis of HIBD. Snhg3 expression was significantly down-regulated in the neonatal brain and primary hippocampal cells response to hypoxic/ischemic stress. Snhg3 overexpression protected against hypoxic/ischemic-induced brain injury in vivo and hippocampal cell injury in vitro. Snhg3 acted as the sponge of miR-196 in the hippocampal cells by regulating the expression of miR-196 target genes, XIAP and CAAP1. Moreover, Snhg3 overexpression decreased brain infarct size and ameliorated hypoxic-ischemic neonatal brain damage. This study suggests that Snhg3 is a potential target for the treatment of HIBD.

Modulation of autophagy in traumatic brain injury

Traumatic brain injury (TBI) is defined as a traumatically induced structural injury or physiological disruption of brain function as a result of external forces, leading to adult disability and death. A growing body of evidence reveals that alterations in autophagy-related proteins exist extensively in both experimentally and clinically after TBI. Of note, the autophagy pathway plays an essential role in pathophysiological processes, such as oxidative stress, inflammatory response, and apoptosis, thus contributing to neurological properties of TBI. With this in mind, this review summarizes a comprehensive overview on the beneficial and detrimental effects of autophagy in pathophysiological conditions and how these activities are linked to the pathogenesis of TBI. Moreover, the relationship between oxidative stress, inflammation, apoptosis, and autophagy occur TBI. Ultimately, multiple compounds and various drugs targeting the autophagy pathway are well described in TBI. Therefore, autophagy flux represents a potential clinical therapeutic value for the treatment of TBI and its complications.