LncRNA SNHG3 promotes autophagy-induced neuronal cell apoptosis by acting as a ceRNA for miR-485 to up-regulate ATG7 expression

Investigating SNHG3 and BCYRN1 lncRnas expression in the peripheral blood cells of multiple sclerosis patients

BACKGROUND

MS (Multiple sclerosis) is a progressive neurologic disorder often appearing in the third decade of life. MS is the most frequent demyelinating disease of the central nervous system. The development of MS is influenced by environmental, genetic, and epigenetic factors. The bulk of the human transcriptome comprises lncRNAs, which play crucial regulatory roles. We aimed to assess the SNHG3 and BCYRN1 lncRNA expression in blood samples from MS patients and how these lncRNAs and disease activity are related.

METHODS

A total of 100 MS patients, including 8 primary progressive (PP), 82 relapsing-remitting (RR), and 10 secondary progressive (SP) MS, as well as 100 healthy controls, had their blood samples taken. Gene expression was assessed using quantitative real-time PCR. Recognizing the receiver operating characteristic (ROC) curve analysis, the diagnostic potential of lncRNA levels was evaluated.

RESULTS

Expressions of SNHG3 and BCYRN1 were found to have significantly increased (p < 0.0001). SNHG3 expression level showed significant differences compared to age groups and MS subtypes (p value = 0.001 and p value = 0.02).Furthermore, patients with a family history showed elevated BCYRN1 expression with a p value of 0.01. Considering the age factor, BCYRN1 exhibits altered expression levels in patient groups compared to healthy controls (p value 0.04). Additionally, the novel biomarkers SNHG3 and BCYRN1 can be used to diagnose MS (AUC = 0.97 and AUC = 0.88, respectively).

DISCUSSION

Increased levels of SNHG3 and BCYRN1 in the serum may serve as potential molecular biomarkers for the MS diagnosis.

Insights on E1-like enzyme ATG7: functional regulation and relationships with aging-related diseases

Autophagy is a dynamic self-renovation biological process that maintains cell homeostasis and is responsible for the quality control of proteins, organelles, and energy metabolism. The E1-like ubiquitin-activating enzyme autophagy-related gene 7 (ATG7) is a critical factor that initiates classic autophagy reactions by promoting the formation and extension of autophagosome membranes. Recent studies have identified the key functions of ATG7 in regulating the cell cycle, apoptosis, and metabolism associated with the occurrence and development of multiple diseases. This review summarizes how ATG7 is precisely programmed by genetic, transcriptional, and epigenetic modifications in cells and the relationship between ATG7 and aging-related diseases.

Orchestrating Cellular Balance: ncRNAs and RNA Interactions at the Dominant of Autophagy Regulation in Cancer

Autophagy, a complex and highly regulated cellular process, is critical for the maintenance of cellular homeostasis by lysosomal degradation of cellular debris, intracellular pathogens, and dysfunctional organelles. It has become an interesting and attractive topic in cancer because of its dual role as a tumor suppressor and cell survival mechanism. As a highly conserved pathway, autophagy is strictly regulated by diverse non-coding RNAs (ncRNAs), ranging from short and flexible miRNAs to lncRNAs and even circRNAs, which largely contribute to autophagy regulatory networks via complex RNA interactions. The potential roles of RNA interactions during autophagy, especially in cancer procession and further anticancer treatment, will aid our understanding of related RNAs in autophagy in tumorigenesis and cancer treatment. Herein, we mainly summarized autophagy-related mRNAs and ncRNAs, also providing RNA-RNA interactions and their potential roles in cancer prognosis, which may deepen our understanding of the relationships between various RNAs during autophagy and provide new insights into autophagy-related therapeutic strategies in personalized medicine.

Competing endogenous RNAs in human astrocytes: crosstalk and interacting networks in response to lipotoxicity

Neurodegenerative diseases (NDs) are characterized by a progressive deterioration of neuronal function, leading to motor and cognitive damage in patients. Astrocytes are essential for maintaining brain homeostasis, and their functional impairment is increasingly recognized as central to the etiology of various NDs. Such impairment can be induced by toxic insults with palmitic acid (PA), a common fatty acid, that disrupts autophagy, increases reactive oxygen species, and triggers inflammation. Although the effects of PA on astrocytes have been addressed, most aspects of the dynamics of this fatty acid remain unknown. Additionally, there is still no model that satisfactorily explains how astroglia goes from being neuroprotective to neurotoxic. Current incomplete knowledge needs to be improved by the growing field of non-coding RNAs (ncRNAs), which is proven to be related to NDs, where the complexity of the interactions among these molecules and how they control other RNA expressions need to be addressed. In the present study, we present an extensive competing endogenous RNA (ceRNA) network using transcriptomic data from normal human astrocyte (NHA) cells exposed to PA lipotoxic conditions and experimentally validated data on ncRNA interaction. The obtained network contains 7 lncRNA transcripts, 38 miRNAs, and 239 mRNAs that showed enrichment in ND-related processes, such as fatty acid metabolism and biosynthesis, FoxO and TGF-β signaling pathways, prion diseases, apoptosis, and immune-related pathways. In addition, the transcriptomic profile was used to propose 22 potential key controllers lncRNA/miRNA/mRNA axes in ND mechanisms. The relevance of five of these axes was corroborated by the miRNA expression data obtained in other studies. MEG3 (ENST00000398461)/hsa-let-7d-5p/ATF6B axis showed importance in Parkinson's and late Alzheimer's diseases, while AC092687.3/hsa-let-7e-5p/[SREBF2, FNIP1, PMAIP1] and SDCBP2-AS1 (ENST00000446423)/hsa-miR-101-3p/MAPK6 axes are probably related to Alzheimer's disease development and pathology. The presented network and axes will help to understand the PA-induced mechanisms in astrocytes, leading to protection or injury in the CNS under lipotoxic conditions as part of the intricated cellular regulation influencing the pathology of different NDs. Furthermore, the five corroborated axes could be considered study targets for new pharmacologic treatments or as possible diagnostic molecules, contributing to improving the quality of life of millions worldwide.

Role of Long Non-coding RNA in Nerve Regeneration

Nerve injury can be caused by a variety of factors. It often takes a long time to repair a nerve injury and severe nerve injury is even difficult to heal. Therefore, increasing attention has focused on nerve injury and repair. Long non-coding RNA (lncRNA) is a newly discovered non-coding RNA with a wide range of biological activities. Numerous studies have shown that a variety of lncRNAs undergo changes in expression after nerve injury, indicating that lncRNAs may be involved in various biological processes of nerve repair and regeneration. Herein, we summarize the biological roles of lncRNAs in neurons, glial cells and other cells during nerve injury and regeneration, which will help lncRNAs to be better applied in nerve injury and regeneration in the future.

LncRNA SNHG3 Promotes Sevoflurane-Induced Neuronal Injury by Activating NLRP3 via NEK7

BACKGROUND

Early exposure to sevoflurane may cause brain tissue degeneration; however, the mechanism involved in this process has not been explored. In this study, we investigated the role of long non-coding RNA small nucleolar RNA host gene 3 (lncRNA SNHG3) in sevoflurane-induced neuronal injury.

METHODS

The injury models of HT22 and primary cultures of neurons were constructed using sevoflurane treatment. The WST-8 reduction was detected by CCK-8 assay, the level of inflammatory factors was detected by enzyme-linked immunosorbent assay (ELISA), and cell pyroptosis was detected by flow cytometry. The expression of genes and proteins was detected by qRT-PCR and Western blot, respectively. The level of β-tubulin III in primary cultures of hippocampal neurons was analyzed by immunofluorescence. The relationship among SNHG3, PTBP1 and NEK7 was confirmed by RIP assay.

RESULTS

The expression of SNHG3 and NEK7 were enhanced in sevoflurane-treated HT22 cells. Sevoflurane inhibited the WST-8 reduction in a concentration-dependent manner, promoted the pyroptosis, and increased pyroptosis-related protein expression. SNHG3 knockdown significantly inhibited sevoflurane-induced pyroptosis and inflammatory injury in HT22 cells and primary cultures of neurons. Furthermore, SNHG3 regulated NEK7 expression by binding to PTBP1. NEK7 knockdown reversed the decrease in WST-8 reduction, inhibited pyroptosis, and decreased the release of inflammatory factors and pyroptosis-related protein expression by inactivation of NLRP3 signaling in sevoflurane-induced HT22 cells. Moreover, NEK7 overexpression attenuated the effect of SNHG3 knockdown on neuronal pyroptosis and inflammation injury.

CONCLUSION

Downregulation of SNHG3 attenuates sevoflurane-induced neuronal inflammation and pyroptosis by mediating the NEK7/NLRP3 axis, suggesting that SNHG3 could be a potential target gene for neuronal injury.

The autophagy in ischemic stroke: A regulatory role of non-coding-RNAs

Ischemic stroke (IS) is a central nervous system neurological disorder ascribed to an acute focal trauma, with high mortality and disability, leading to a heavy burden on family and society. Autophagy is a self-digesting process by which damaged organelles and useless proteins are recycled to maintain cellular homeostasis, and plays a pivotal role in the process of IS. Non-coding RNAs (ncRNAs), mainly contains microRNA, long non-coding RNA and circular RNA, have been extensively investigated on regulation of autophagy in human diseases. Recent studies have implied that ncRNAs-regulating autophagy participates in pathophysiological process of IS, including cell apoptosis, inflammation, oxidative stress, blood-brain barrier damage and glial activation, which indicates that regulating autophagy by ncRNAs may be beneficial for IS treatment. This review summarizes the role of autophagy in IS, as well as focuses on the role of ncRNAs-mediated autophagy in IS, for the development of potential therapeutic strategies in this disease.

Bioinformatic Analysis of lncRNA Mediated CeRNA Network in Intestinal Ischemia/Reperfusion Injury

INTRODUCTION

Recently, accumulating studies have reported the roles of competitive endogenous RNA (ceRNA) networks in ischemia/reperfusion (I/R) injury in several organs, including the liver, kidney, heart, brain, and intestine. However, the functions and mechanisms of long noncoding RNAs (lncRNAs)-which serve as ceRNA networks in intestinal I/R injury-remain elusive.

METHODS

RNA expression data were retrieved from the National Center for Biotechnology Information-Gene Expression Omnibus database. Differentially expressed microRNAs (miRNAs) (miDEGs) were explored between the sham and intestinal I/R injury samples. Next, targeted lncRNAs and messenger RNAs in the database were matched based on miDEGs. Hub ceRNA networks were constructed and visualized via Cytoscape. Intersection analysis was performed to screen mDEGs between two datasets. Finally, the vital nodes of the ceRNA networks were validated by quantitative PCR.

RESULTS

A total of 189 miDEGs were identified. Forty miRNAs were found to be associated with 240 predicted target genes from miRWalk 3.0. The ceRNA network was constructed with 10 miRNAs, including the 1700020114Rik/mmu-miR-7a-5p/Klf4 axis. Furthermore, the expression of lncRNA 1700020114Rik (P < 0.05) and messenger RNA Klf4 (P < 0.01) was markedly decreased in mouse models of intestinal I/R injury, whereas the expression level of mmu-miR-7a-5p was significantly increased (P < 0.05).

CONCLUSIONS

The results provide novel insights into the molecular mechanism of ceRNA networks in intestinal I/R injury and highlight the potential of the 170002700020114Rik/mmu-miR-7a-5p/Klf4 axis in the prevention and treatment of intestinal I/R injury.

BMP9 promotes autophagy and inhibits migration and invasion in breast cancer cells through the c-Myc/SNHG3/mTOR signaling axis

We previously reported that BMP9 inhibited breast cancer progression. However, the precise molecular mechanism is still unknown. Based on our RNA-sequencing (RNA-seq) results, BMP9 significantly down-regulated the expression of long non-coding RNA SNHG3. Exogenous BMP9 promoted autophagy and inhibited migration and invasion in MDA-MB-231 cells, which was effectively blunted by SNHG3 overexpression. Interestingly, SNHG3 was negatively connected with autophagy. Knockdown of SNHG3 induced autophagy by increasing the formation of autophagic vacuoles and thus inhibited the migration and invasion of MDA-MB-231 cells. Mechanically, BMP9-SNHG3 activated AMPK, AKT and mTOR signaling pathways to induce autophagy and inhibit migration and invasion. Meanwhile, BMP9 regulated SNHG3 transcription by suppressing c-Myc entry into the nucleus. In conclusion, BMP9 promotes autophagy and inhibits migration and invasion in breast cancer cells through the c-Myc/SNHG3/mTOR signaling axis, which might offer a fresh perspective on BMP9's breast cancer-inhibiting properties.

The regulatory roles of circular RNAs via autophagy in ischemic stroke

Ischemic stroke (IS) is a severe disease with a high disability, recurrence, and mortality rates. Autophagy, a highly conserved process that degrades damaged or aging organelles and excess cellular components to maintain homeostasis, is activated during IS. It influences the blood–brain barrier integrity and regulates apoptosis. Circular RNAs (circRNAs) are novel non-coding RNAs involved in IS-induced autophagy and participate in various pathological processes following IS. In addition, they play a role in autophagy regulation. This review summarizes current evidence on the roles of autophagy and circRNA in IS and the potential mechanisms by which circRNAs regulate autophagy to influence IS injury. This review serves as a basis for the clinical application of circRNAs as novel biomarkers and therapeutic targets in the future.

Identification of senescence-associated long non-coding RNAs to predict prognosis and immune microenvironment in patients with hepatocellular carcinoma

Background: Cellular senescence plays a complicated and vital role in cancer development because of its divergent effects on tumorigenicity. However, the long non-coding RNAs (lncRNAs) associated with tumor senescence and their prognostic value in hepatocellular carcinoma (HCC) remain unexplored. Methods: The trans-cancer oncogene-induced senescence (OIS) signature was determined by gene set variation analysis (GSVA) in the cancer genome atlas (TCGA) dataset. The OIS-related lncRNAs were identified by correlation analyses. Cox regression analyses were used to screen lncRNAs associated with prognosis, and an optimal predictive model was created by regression analysis of the least absolute shrinkage and selection operator (LASSO). The performance of the model was evaluated by Kaplan-Meier survival analyses, nomograms, stratified survival analyses, and receiver operating characteristic curve (ROC) analyses. Gene set enrichment analysis (GSEA) and cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT) were carried out to explore the functional relevance and immune cell infiltration, respectively. Results: Firstly, we examined the pan-cancer OIS signature, and found several types of cancer with OIS strongly associated with the survival of patients, including HCC. Subsequently, based on the OIS signature, we identified 76 OIS-related lncRNAs with prognostic values in HCC. We then established an optimal prognostic model based on 11 (including NRAV, AC015908.3, MIR100HG, AL365203.2, AC009005.1, SNHG3, LINC01138, AC090192.2, AC008622.2, AL139423.1, and AC026356.1) of these lncRNAs by LASSO-Cox regression analysis. It was then confirmed that the risk score was an independent and potential risk indicator for overall survival (OS) (HR [95% CI] = 4.90 [2.74-8.70], p < 0.001), which outperforms those traditional clinicopathological factors. Furthermore, patients with higher risk scores also showed more advanced levels of a proinflammatory senescence-associated secretory phenotype (SASP), higher infiltration of regulatory T (Treg) cells and lower infiltration of naïve B cells, suggesting the regulatory effects of OIS on immune microenvironment. Additionally, we identified NRAV as a representative OIS-related lncRNA, which is over-expressed in HCC tumors mainly driven by DNA hypomethylation. Conclusion: Based on 11 OIS-related lncRNAs, we established a promising prognostic predictor for HCC patients, and highlighted the potential immune microenvironment-modulatory roles of OIS in HCC, providing a broad molecular perspective of tumor senescence.

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.

Comprehensive Analysis of lncRNAs, miRNAs and mRNAs in Mouse Hippocampus With Hepatic Encephalopathy

Hepatic encephalopathy (HE) often presents with varying degrees of cognitive impairment. However, the molecular mechanism of its cognitive impairment has not been fully elucidated. Whole transcriptome analysis of hippocampus between normal and HE mice was performed by using RNA sequencing. 229 lncRNAs, 49 miRNAs and 363 mRNAs were differentially expressed in HE mice. The lncRNA-miRNA-mRNA interaction networks were established, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed. Dysregulated RNAs in interaction networks were mainly involved in synaptic plasticity and the regulation of learning and memory. In NH4Cl-treated hippocampal neurons, the dendritic spine density and maturity decreased significantly, the amplitude and frequency of mIPSC increased, while the amplitude and frequency of mEPSC decreased. These manifestations can be reversed by silencing SIX3OS1. Further research on these no-coding RNAs may lead to new therapies for the treatment and management of brain dysfunction caused by HE.

Bioinformatics Analysis Identified the Hub Genes, mRNA–miRNA–lncRNA Axis, and Signaling Pathways Involved in Rheumatoid Arthritis Pathogenesis

Objective

Rheumatoid arthritis (RA) is a nonspecific, chronic, systemic autoimmune disease characterized by symmetric polyarticular synovitis. Bioinformatics analysis of potential biomarkers, mRNA–miRNA–lncRNA axes, and signaling pathways in the pathogenesis of RA provides potential targets and theoretical basis for further research on RA.

Methods

The GSE1919 and GSE77298 datasets were downloaded from the Gene Expression Omnibus database (http://www.ncbi.nlm.nih.gov/geo). Perl was used to perform data merging, and R was used to perform batch correction. The “limma” package of R was used to screen differentially expressed genes, and the “clusterProfiler” package was used to perform enrichment analysis of the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. Search Tool for the Retrieval of Interacting Genes/Proteins was used to construct the protein–protein interaction network, Cytoscape was used for module analysis, and R was used to screen for hub genes. GraphPad Prism was used to plot the receiver operating characteristic curve of the hub genes. Gene set enrichment analysis and competitive endogenous RNA network analysis were performed on hub genes with the greatest diagnostic values. The hub gene with the greatest diagnostic value was verified using immunohistochemical staining.

Results

We obtained nine hub genes (ITGB2, VAMP8, HLA-A, PTAFR, SYK, FCER1G, HLA-DPB1, LCP2, and ACTR2) and four mRNA–miRNA–lncRNA axes (ITGB2-hsa-miR-486-3p-SNHG3, ITGB2-hsa-miR-338-5p-XIST, ITGB2-hsa-miR-5581-3p-XIST, and ITGB2-hsa-miR-1226-5p-XIST) related to the pathogenesis of RA. The nine hub genes were highly expressed, and ITGB2 had the highest diagnostic value for RA. We also identified signaling pathways related to the pathogenesis of RA: Fc epsilon Rl and chemokine signaling pathways. The immunohistochemical results showed that ITGB2 expression was significantly upregulated in RA.

Conclusion

The hub genes, mRNA–miRNA–lncRNA axes, and signaling pathways related to RA pathogenesis identified in this study provide a new research direction for the mechanism, diagnosis, and treatment of RA.

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.

Long non-coding RNA LINC01559 exerts oncogenic role via enhancing autophagy in lung adenocarcinoma

BACKGROUND

Long non-coding RNAs (lncRNAs) have been verified to play fatal role in regulating the progression of lung adenocarcinoma (LUAD). Although lncRNAs play important role in regulating the autophagy of tumor cells, the function and molecular mechanism of LINC01559 in regulating lung cancer development remain to be elucidated.

METHOD AND MATERIALS

In this study, we used bioinformatics to screen out autophagy-related lncRNAs from TCGA-LUAD repository. Then the least absolute shrinkage and selection operator (LASSO) regression was applied to establish the signature of autophagy-related lncRNAs so that clinical characteristics and survival in LUAD patients be evaluated. Finally, we selected the most significant differences lncRNA, LINC01559, to verify its function in regulating LUAD progression in vitro.

RESULTS

We found high expression of LINC01559 indicates lymph node metastasis and poor prognosis. Besides, LINC01559 promotes lung cancer cell proliferation and migration in vitro, by enhancing autophagy signal pathway via sponging hsa-miR-1343-3p.

CONCLUSION

We revealed a novel prognostic model based on autophagy-related lncRNAs, and provide a new therapeutic target and for patients with lung adenocarcinoma named LINC01559.

Targeting Long Non-Coding RNA TTN-AS1 Suppresses Bladder Cancer Progression

Background: To explore the biological and clinical effects of titin-antisense RNA1 (TTN-AS1) in bladder cancer (BC) and the association between TTN-AS1 and activating transcription factor 2 (ATF2) in BC. Methods: The Kaplan-Meier method was performed to analyze the association between the expression of TTN-AS1 and prognosis of BC patients from TCGA data set and our institution. Quantitative real-time PCR (RT-PCR) was conducted to explore the expression of TTN-AS1 between the patients who underwent TURBT and Re-TURBT. MTT, colony formation, and tumor formation assays were conducted to evaluate the effect of TTN-AS1 on the ability of proliferation in BC cell lines. Transwell assay was performed to evaluate the effect of TTN-AS1 on the ability of invasion in BC cell lines. Bioinfomatics and immunohistochemical staining was used to identify the relationship between TTN-AS1 and ATF2. Results: The higher expression of TTN-AS1 was related to poorer disease-free survival (DFS) in patients with BC. The expression of TTN-AS1 was higher in BC patients who underwent Re-TURBT compared with BC patients who underwent TURBT. Knocking down TTN-AS1 resulted in inhibiting the ability of proliferation and invasion of BC cells. ATF2 may serve as a downstream target of TTN-AS1 in BC, and the high expression of ATF2 is also related to adverse DFS. Conclusion: Our study reveals that TTN-AS1 serves as an oncogene by activating ATF2 in BC. The findings suggest that TTN-AS1 may act as a novel therapeutic target for patients with BC.

Long non-coding RNA MEG3 regulates autophagy after cerebral ischemia/reperfusion injury

Severe cerebral ischemia/reperfusion injury has been shown to induce high-level autophagy and neuronal death. Therefore, it is extremely important to search for a target that inhibits autophagy activation. Long non-coding RNA MEG3 participates in autophagy. However, it remains unclear whether it can be targeted to regulate cerebral ischemia/reperfusion injury. Our results revealed that in oxygen and glucose deprivation/reoxygenation-treated HT22 cells, MEG3 expression was obviously upregulated, and autophagy was increased, while knockdown of MEG3 expression greatly reduced autophagy. Furthermore, MEG3 bound miR-181c-5p and inhibited its expression, while miR-181c-5p bound to autophagy-related gene ATG7 and inhibited its expression. Further experiments revealed that mir-181c-5p overexpression reversed the effect of MEG3 on autophagy and ATG7 expression in HT22 cells subjected to oxygen and glucose deprivation/reoxygenation. In vivo experiments revealed that MEG3 knockdown suppressed autophagy, infarct volume and behavioral deficits in cerebral ischemia/reperfusion mice. These findings suggest that MEG3 knockdown inhibited autophagy and alleviated cerebral ischemia/reperfusion injury through the miR-181c-5p/ATG7 signaling pathway. Therefore, MEG3 can be considered as an intervention target for the treatment of cerebral ischemia/reperfusion injury. This study was approved by the Animal Ethics Committee of the First Affiliated Hospital of Zhengzhou University, China (approval No. XF20190538) on January 4, 2019.

Targeting autophagy in ischemic stroke: From molecular mechanisms to clinical therapeutics

Stroke constitutes the second leading cause of death and a major cause of disability worldwide. Stroke is normally classified as either ischemic or hemorrhagic stroke (HS) although 87% of cases belong to ischemic nature. Approximately 700,000 individuals suffer an ischemic stroke (IS) in the US each year. Recent evidence has denoted a rather pivotal role for defective macroautophagy/autophagy in the pathogenesis of IS. Cellular response to stroke includes autophagy as an adaptive mechanism that alleviates cellular stresses by removing long-lived or damaged organelles, protein aggregates, and surplus cellular components via the autophagosome-lysosomal degradation process. In this context, autophagy functions as an essential cellular process to maintain cellular homeostasis and organismal survival. However, unchecked or excessive induction of autophagy has been perceived to be detrimental and its contribution to neuronal cell death remains largely unknown. In this review, we will summarize the role of autophagy in IS, and discuss potential strategies, particularly, employment of natural compounds for IS treatment through manipulation of autophagy.

Interference with long noncoding RNA SNHG3 alleviates cerebral ischemia-reperfusion injury by inhibiting microglial activation

Neuroinflammation plays a strong part in cerebral ischemia-reperfusion injury, and microglial activation is regarded as a marker for neuroinflammation. Long noncoding RNA small nucleolar RNA host gene 3 (lncRNA SNHG3) is heavily expressed in cerebral ischemia-reperfusion models, but its mechanism is rarely studied. This study aims to explore whether SNHG3 is involved in cerebral ischemia-reperfusion injury by promoting microglial activation and inflammatory factor secretion. Activation of microglia was induced through oxygen-glucose deprivation/reoxygenation (OGD/R) or LPS and the cerebral ischemia-reperfusion injury in mice was induced by transient middle cerebral artery occlusion (tMCAO). Levels of SNHG3, IL-6, and TNF-α were determined by quantitative real-time PCR. Immunofluorescence was used for the detection of Iba-1 expression. Western blot was carried out for the detection of Iba-1 and histone deacetylase 3 (HDAC3) protein levels. An ELISA was performed to detect TNF-α and IL-6 levels. RNA pull-down, RNA immunoprecipitation, and co-Immunoprecipitation assays were conducted to detect the binding between SNHG3 and HDAC3. A H&E staining assay was applied to observe pathologic changes. Microglial activation was observed with immunohistochemistry. Levels of SNHG3, microglial activation marker Iba-1, proinflammatory factors (TNF-α and IL-6) were highly expressed in cell models (treated with OGD/R or LPS) and mouse models (tMCAO). Besides, SNHG3 could bind to HDAC3 and promote its expression. Through further study, we found that SNHG3 could stabilize the protein levels of HDAC3 and inhibit the ubiquitination of HDAC3. Furthermore, interference with SNHG3 down-regulated the levels of HDAC3, Iba-1, TNF-α, and IL-6, whereas the overexpression of HDAC3 reversed the results. The H&E staining assay demonstrated that the condition of vacuoles of different sizes, uneven cytoplasmic staining, and inflammatory infiltration in the brain tissue was improved by interference with SNHG3. The immunohistochemistry result showed that microglial activation marker Iba-1 was increased in the shRNA-SNHG3 group, indicating that interference with SNHG3 inhibited the activation of microglia in the brain. LncRNA SNHG3 aggravated cerebral ischemia-reperfusion injury by promoting the activation of microglia, increasing the levels of HDAC3, and the secretion of inflammatory factors.

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.