Long Coding RNA XIST Contributes to Neuronal Apoptosis through the Downregulation of AKT Phosphorylation and Is Negatively Regulated by miR-494 in Rat Spinal Cord Injury

[Non-coding RNAs as therapeutic targets in spinal cord injury]

Spinal cord injury (SCI) may be followed by persistent motor dysfunction and somatosensory disturbances that negatively influences the quality of life of patients and creates a significant economic burden. Analysis of secondary biological processes associated with changes in genetic expression is becoming increasingly important every day in understanding the pathophysiology of spinal cord injury. The results of international sequencing of the human genome were analyzed in 2004. These data revealed about 20,000 protein-coding genes covering near 2% of the total genomic sequence. The vast majority of gene transcripts are actually characterized as non-coding RNAs (ncRNAs). These RNA clusters do not encode functional proteins and ensure post-transcriptional regulation of gene expression. The clusters may be small (approximately 20 nucleotides) known as miRNAs or the transcripts can enroll over 200 nucleotides defined as long non-coding RNAs (lncRNAs). Some modern studies describe transient expression of microRNA in case of spinal cord injury. These RNAs are associated with inflammation and apoptosis, functional recovery and regeneration. Large-scale genomic analysis has demonstrated the existence of multiple lncRNAs whose expression is associated with some processes of spinal cord injury. lncRNA can be divided into two categories depending on the position in relation to the coding genes: intergenic and intragenic. Intergenic lncRNAs is currently the most studied class. Intragenic lncRNAs can be subdivided depending on the overlap of the coding genes (antisense, intron, etc.). According to recent studies, long non-coding RNAs are abundantly present in the tissues of central nervous system and may be crucial in the pathogenesis of certain diseases of nervous system. At the cellular level, it has been shown that lncRNAs regulate the expression of protein-coding RNAs. Moreover, these molecules are involved into such processes as neuronal death, demyelination and glia activation. This review is devoted to the role of ncRNAs in the pathogenesis of spinal cord injury and their potential use as targets for the treatment of consequences of spinal cord injury.

Interactions Among lncRNAs/circRNAs, miRNAs, and mRNAs in Neuropathic Pain

Neuropathic pain (NP) is directly caused by an injury or disease of the somatosensory nervous system. It is a serious type of chronic pain that is a burden to the economy and public health. Although recent studies have improved our understanding of NP, its pathogenesis has not been fully elucidated. Noncoding RNAs, including lncRNAs, circRNAs, and miRNAs, are involved in the pathological development of NP through many mechanisms. In addition, extensive evidence suggests that novel regulatory mechanisms among lncRNAs/circRNAs, miRNAs, and mRNAs play a crucial role in the pathophysiological process of NP. In this review, we comprehensively summarize the regulatory relationship among lncRNAs/circRNAs, miRNAs, and mRNAs and emphasize the important role of the lncRNA/circRNA-miRNA-mRNA axis in NP.

Dysregulation in the expression of (lncRNA-TSIX, TP53INP2 mRNA, miRNA-1283) in spinal cord injury

AIM

The objective of this study is to examine the alterations in the levels of expression of serum lncRNA-TSIX, TP53INP2 mRNA, miRNA-1283 in spinal cord injured (SCI) patients versus healthy control.

METHOD

The expression of the selected RNAs in the sera was determined in 23 patients suffering from acute spinal cord injury, 41 individuals with chronic spinal cord injury, and 36 healthy control using real-time reverse-transcription polymerase chain reaction method.

RESULTS

The results showed that lncRNA-TSIX and the TP53INP2 mRNA expression levels in SCI patients was overexpressed in comparison to the control group alongside with a significant downregulation of miR-1283. Statistically,there was a highly significant positive correlation between lnc-RNA-TRIX and TP53INP2 mRNA with inverse correlation between miRNA-1283 and lnc-RNA-TRIX based on fold changes.

CONCLUSION

Up-regulation of lncRNA-TSIX, TP53INP2 mRNA with downregulation of miRNA-1283 might be closely associated with progression of SCI.

Xist attenuates acute inflammatory response by female cells

Biological sex influences inflammatory response, as there is a greater incidence of acute inflammation in men and chronic inflammation in women. Here, we report that acute inflammation is attenuated by X-inactive specific transcript (Xist), a female cell-specific nuclear long noncoding RNA crucial for X-chromosome inactivation. Lipopolysaccharide-mediated acute inflammation increased Xist levels in the cytoplasm of female mouse J774A.1 macrophages and human AML193 monocytes. In both cell types, cytoplasmic Xist colocalizes with the p65 subunit of NF-κB. This interaction was associated with reduced NF-κB nuclear migration, suggesting a novel mechanism to suppress acute inflammation. Further supporting this hypothesis, expression of 5' XIST in male cells significantly reduced IL-6 and NF-κB activity. Adoptive transfer of male splenocytes expressing Xist reduced acute paw swelling in male mice indicating that Xist can have a protective anti-inflammatory effect. These findings show that XIST has functions beyond X chromosome inactivation and suggest that XIST can contribute to sex-specific differences underlying inflammatory response by attenuating acute inflammation in women.

LncRNA XIST serves as a ceRNA to regulate the expression of ASF1A, BRWD1M, and PFKFB2 in kidney transplant acute kidney injury via sponging hsa-miR-212-3p and hsa-miR-122-5p

We aimed to identify potential mechanism associated with acute kidney injury (AKI) after kidney transplantation. The dataset GSE53771, which contained 18 zero-hour (ZERO group) and 18 selected post-transplant (POST group) biopsy samples from 18 kidney allografts (8 AKI and 10 controls) was downloaded from GEO database. Differentially expressed miRNAs (DEMIs) were screened using limma package, and bidirectional hierarchical clustering of the DEMIs was performed using the pheatmap package. Target genes of DEMIs were predicted by miRWalk 2.0, miRNA-target genes networks were presented using Cytoscape, protein-protein interaction (PPI) networks were constructed by STRING (version:10.0) database, and competing endogenous RNAs (ceRNA) regulating network were constructed using Cytoscape. In ZERO and POST groups, a total of 4 and 24 differentially expressed miRNAs were obtained in AKI samples compared with control, respectively. Specifically, 71 lncRNAs were obtained to interact with five miRNAs (hsa-miR-215-5p, hsa-miR-192-5p, hsa-miR-422a, hsa-miR-212-3p and hsa-miR-122-5p). Histone chaperone ASF1A (ASF1A) and bromodomain and WD repeat-containing protein 1(BRWD1) were targeted by hsa-miR-212-3p in PPI network. In ceRNA network, lncRNA XIST could interact with four miRNAs (hsa-miR-212-3p, hsa-miR-122-5p, hsa-miR-215-5p, and hsa-miR-192-5p). LncRNA XIST might serve as a ceRNA to sponge hsa-miR-212-3p to regulate the development of AKI via altering the expression of ASF1A/BRWD1. Furthermore, lncRNA XIST could also interact with hsa-miR-122-5p to modulate the expression of PFKFB2 in thyroid hormone signaling pathway and AMPK signaling pathway. LncRNA XIST can serve as a ceRNA to sponge hsa-miR-212-3p and hsa-miR-122-5p to regulate AKI progression via modulating the expression of ASF1A, BRWD1, and PFKFB2.[Figure: see text].

Noncoding RNAs: New regulatory code in chondrocyte apoptosis and autophagy

Osteoarthritis (OA) is a bone and joint disease characterized by progressive cartilage degradation. In the face of global trends of population aging, OA is expected to become the fourth most common disabling disease by 2020. Nevertheless, the detailed pathogenesis of OA has not yet been elucidated. Noncoding RNAs (ncRNAs), including long noncoding RNAs, microRNAs, and circular RNAs, do not encode proteins but have recently emerged as important regulators of apoptosis and autophagy of chondrocytes, thereby highlighting a potential role in chondrocyte injury leading to OA onset and progression. We here review recent findings on these regulatory roles of ncRNAs to provide new directions for research on the pathogenesis of OA and offer new therapeutic targets for prevention and treatment. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.

Interactions Among Regulatory Non-coding RNAs Involved in Cardiovascular Diseases

Non-coding RNAs (ncRNAs) are important regulatory players in human cells that have been shown to modulate different cellular processes and biological functions through controlling gene expression, being also involved in pathological conditions such as cardiovascular diseases. Among them, long non-coding RNAs (lncRNAs) and circular (circRNAs) could act as competing endogenous RNAs (ceRNAs) sequestering other ncRNAs. This entangled network of interactions has been reported to trigger the decay of the targeted ncRNAs having important roles in gene regulation. Growing evidences have been demonstrated that the regulatory mechanism underlying the crosstalk between different ncRNA species, namely lncRNAs, circRNAs and miRNAs has also an important role in the pathophysiological processes of cardiovascular diseases. In this chapter, the main regulatory relationship among lncRNAs, circRNAs and miRNAs were summarized and their role in the control and development of cardiovascular diseases was highlighted.

Targeting CARD6 attenuates spinal cord injury (SCI) in mice through inhibiting apoptosis, inflammation and oxidative stress associated ROS production

Spinal cord injury (SCI) causes long-term and severe disability, influencing the quality of life and triggering serious socioeconomic consequences. Lack of effective pharmacotherapies for SCI is largely attributable to an incomplete understanding of its pathogenesis. Caspase recruitment domain family member 6 (CARD6) was initially suggested to be a protein playing significant role in NF-κB activation. However, the effects of CARD6 on SCI progression remain unknown. In this study, the wild type (CARD6+/+), CARD6 knockout (CARD6-/-) and CARD6 transgenic (TG) mice were subjected to a SCI model in vivo, and in vitro experiments were conducted by treating microglia cells with lipopolysaccharide (LPS). Here, we identified CARD6 as a suppressor of SCI in mice. CARD6 knockout significantly accelerated functional deficits, neuron death and glia activation, whereas CARD6 overexpression resulted in the opposite effects. Both in vivo and in vitro SCI models suggested that CARD6 knockout markedly promoted apoptosis by increasing Cyto-c release to cytosol from mitochondria and activating Caspase-3 signaling. In addition, CARD6 knockout mice exhibited stronger inflammatory response after SCI, as evidenced by the significantly elevated expression of pro-inflammatory cytokines TNF-α, IL-1β and IL-6, which was largely through enhancing the activation of NF-κB signaling.

Knockdown of long noncoding RNA XIST mitigates the apoptosis and inflammatory injury of microglia cells after spinal cord injury through miR-27a/Smurf1 axis

Spinal cord injury (SCI) is a devastating neuropathological condition. Long noncoding RNA X-inactive specific transcript (XIST) is an acknowledged cancer-related gene and participates in the development of SCI. However, role of XIST in SCI remains to be well revealed. Expression of XIST, miRNA-27a-3p (miR-27a) and smad ubiquitination regulatory factor 1 (Smurf1) was detected using RT-qPCR and western blotting. Cell apoptosis and inflammatory injury were assessed by sulforhodamine B (SRB) assay, flow cytometry, western blotting and enzyme-linked immunosorbent assay. The relationship among miR-27a, XIST and Smurf1 was confirmed by dual-luciferase reporter assay, RNA immunoprecipitation and RNA pull-down assay. As a result, we observed higher level of XIST and Smurf1, but lower level of miR-27a in SCI rats and lipopolysaccharide (LPS)-induced primary microglial cells. in vitro, LPS induced SCI microglia cells as described by decreased cell viability and B cell lymphoma 2 (Bcl-2) expression, and increased cell apoptosis rate, Bax and cleaved caspase 3 levels, and tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) secretions. in vivo, a T10 laminectomy caused SCI rats as evidenced by decreased Basso-Beattie-Bresnahan Locomotor Rating Scale (BBB) score and induced expression of Bax, cleaved caspase 3, TNF-α and IL-6. However, silencing of XIST could mitigate the apoptosis and inflammatory injury in LPS-induced microglia and SCI rats. Mechanically, miR-27a interacted with XIST and Smurf1 via target binding. Either miR-27a downregulation or Smurf1 overexpression partially reversed the role of XIST deletion in LPS-treated microglial cells. Collectively, knockdown of XIST could alleviate the apoptosis and inflammatory injury of SCI models in vitro and in vivo through directly modulating miR-27a/Smurf1 axis.

LncRNA MALAT1 promotes neuropathic pain progression through the miR‑154‑5p/AQP9 axis in CCI rat models

The present study investigated the role and molecular mechanism of long non‑coding RNA (lncRNA) metastasis associated lung adenocarcinoma transcript (MALAT)1 in neuropathic pain in rat chronic constriction injury (CCI) model. Reverse transcription‑quantitative PCR and western blot analysis were used to detect the expression levels of MALAT1, microRNA (miR)‑154‑5p and aquaporin (AQP)9 in spinal cord tissue and microglia of CCI rats. ELISA and pain behavioral assays were used to observe the effect of MALAT1 on neuropathic pain and neuroinflammation in model rats, and to verify its molecular mechanism through bioinformatics and luciferase experiments. The results of the present study identified that the expression levels of MALAT1 and AQP9 were upregulated, while miR‑154‑5p was downregulated in spinal cord tissue and microglia of CCI rats. MALAT1 knockdown in CCI model rats significantly induced the occurrence of neuropathic pain, while the upregulation of miR‑154‑5p could reverse this process. The present study also identified that miR‑154‑5p was the target gene of MALAT1, and AQP9 was the target gene of miR‑154‑5p. AQP9 knockdown promoted the occurrence of neuropathic pain. In conclusion, lncRNA MALAT1 promotes the progression of neuropathic pain in rats by reducing miR‑154‑5p and increasing AQP9. The MALAT1/miR‑154‑5p/AQP9 axis can be used as a new therapeutic target for neuropathic pain.

The Mechanisms Underlying PTEN Loss in Human Tumors Suggest Potential Therapeutic Opportunities

In this review, we will first briefly describe the diverse molecular mechanisms associated with PTEN loss of function in cancer. We will then proceed to discuss the molecular mechanisms linking PTEN loss to PI3K activation and demonstrate how these mechanisms suggest possible therapeutic approaches for patients with PTEN-null tumors.

Integrated analysis of competing endogenous RNA (ceRNA) networks in subacute stage of spinal cord injury

This study aims to investigate the genetic and epigenetic mechanisms involved in the pathogenesis of subacute stage of spinal cord injury (SCI). Gene-expression datasets associated with SCI were downloaded from the Gene Expression Omnibus (GEO) database, and differential expression analyses were performed in order to identify differentially expressed genes (DEGs). Multiple network types were constructed and analyzed, including protein-protein-interaction (PPI) network, miRNA-target network, lncRNA-associated competing endogenous RNA (ceRNA) network, and miRNA-transcription factor (TF)-target network. Cluster analyses were performed to identify significant modules. To verify the prediction accuracy of the in-silico identified molecules, qRT-PCR experiments were conducted. The results depicted the Ywhae gene as the hub gene with the highest degree in the PPI network. The ceRNA network identified specific genes (Flna, ID3, and HK2), miRNAs (miR-16-5p, miR-1958, and miR-185-5p), and lncRNAs (Neat1, Xist, and Malat1) as playing critical regulating roles in the pathological mechanisms of SCI. The miRNA-TF-gene interaction network identified four important TFs (Sp1, Trp53, Jun, and Rela). The miRNA-gene-TF interaction loops from the significant modules indicated that miR-325-3p can interact with the Asah1 gene and TF-Sp1 by forming a closed loop. The qRT-PCR experiments verified four selected genes (Flna, ID3, HK2, and Ywhae) and two selected TFs (Jun, and Sp1) as significantly up-regulated following SCI. The results indicated that four genes (Flna, ID3, HK2, and Ywhae), four transcription factors (Sp1, Trp53, Jun, and RelA), two miRNAs (miR-16-5p and miR-325-3p), and three lncRNAs (Neat1, Xist, and Malat1) are likely to be involved in the molecular mechanisms underlying the subacute stage of SCI. These findings uncover putative pathogenic mechanisms involved in SCI and might bear translation significance for future research towards therapeutic development.

Long noncoding RNA XIST participates hypoxia-induced angiogenesis in human brain microvascular endothelial cells through regulating miR-485/SOX7 axis

BACKGROUND

Long non-coding RNAs (lncRNAs) X-inactive specific transcript (XIST) has identified to involve into the tumor cell angiogenesis. However, whether XIST contributes to Human Brain Microvascular Endothelial Cells (HBMEC) angiogenesis as well as potential mechanisms are largely unclear.

METHODS

The expression of XIST, miR-485-3p and SRY-box 7 (SOX7) in HBMEC were altered by transfection. The cell viability, cell migration and tube formation of HBMEC were measured, respectively. The cross-regulations between XIST, miR-485-3p, SOX7, and vascular endothelial growth factor (VEGF) signaling pathway were investigated by RT-qPCR and Western blot assay.

RESULTS

In this study, we characterized the upregulation of XIST in HBMEC under hypoxia condition. Meanwhile, XIST silencing impaired hypoxia-induced cell proliferation, migration and tube formation. Besides, our integrated experiments identified that XIST may competitively bind with miR-485-3p and then modulate the derepression of downstream target SRY-box 7 (SOX7). Mechanically, knockdown of XIST impaired hypoxia-induced angiogenesis via miR-485-3p/SOX7 axis and subsequent suppression of VEGF signaling pathway.

CONCLUSION

Altogether, the present study suggested that XIST is required to maintain VEGF signaling expression in HBMEC under hypoxia condition and plays a vital role in hypoxia-induced angiogenesis via miR-485-3p/SOX7 axis.

The Emerging Role of lncRNAs in Spinal Cord Injury

Spinal cord injury (SCI) is a highly debilitating disease and is increasingly being recognized as an important global health priority. However, the mechanisms underlying SCI have not yet been fully elucidated, and effective therapies for SCI are lacking. Long noncoding RNAs (lncRNAs), which form a major class of noncoding RNAs, have emerged as novel targets for regulating several physiological functions and mediating numerous neurological diseases. Notably, gene expression profile analyses have demonstrated aberrant changes in lncRNA expression in rats or mice after traumatic or nontraumatic SCI. LncRNAs have been shown to be associated with multiple pathophysiological processes following SCI including inflammation, neural apoptosis, and oxidative stress. They also play a crucial role in the complications associated with SCI, such as neuropathic pain. At the same time, some lncRNAs have been found to be therapeutic targets for neural stem cell transplantation and hydrogen sulfide treatment aimed at alleviating SCI. Therefore, lncRNAs could be promising biomarkers for the diagnosis, treatment, and prognosis of SCI. However, further researches are required to clarify the therapeutic effects of lncRNAs on SCI and the mechanisms underlying these effects. In this study, we reviewed the current progress of the studies on the involvement of lncRNAs in SCI, with the aim of drawing attention towards their roles in this debilitating condition.

Knockdown XIST alleviates LPS-induced WI-38 cell apoptosis and inflammation injury via targeting miR-370-3p/TLR4 in acute pneumonia

Pneumonia is an inflammatory disease that occurs in the lungs associated with pathogens or other factors. It has been well established that long noncoding RNA X inactivate-specific transcript (XIST) is involved in several cancers. The present study focused on the effect and detailed mechanism of XIST in lipopolysaccharide (LPS)-induced injury in pneumonia. Here, XIST was silenced by transfection with XIST-targeted siRNA, and then, mRNA expression, cell viability, apoptosis, and protein expression were, respectively, assessed by qRT-PCR, CCK-8, flow cytometry, and Western blotting. Luciferase reporter, RIP, and RNA pull-down assays were used to detect the combination of miR-370-3p and XIST. Besides, the tested proinflammatory factors were analysed by qRT-PCR and Western blot, and their productions were quantified by ELISA. The results showed that XIST expression was robustly increased in serum of patients with acute-stage pneumonia and LPS-induced WI-38 human lung fibroblasts cells. Functional analyses demonstrated that knockdown of XIST remarkably alleviated LPS-induced cell injury through increasing cell viability and inhibiting apoptosis and inflammatory cytokine levels. Mechanistically, XIST functioned as a competitive endogenous RNA (ceRNA) by effectively binding to miR-370-3p and then restoring TLR4 expression. More importantly, miR-370-3p inhibitor abolished the function of XIST knockdown on cell injury and JAK/STAT and NF-κB pathways. Taken together, XIST may be involved in progression of cell inflammatory response, and XIST/miR-370-3p/TLR4 axis thus may shed light on the development of novel therapeutics to the treatment of acute stage of pneumonia. SIGNIFICANCE OF THE STUDY: Our study demonstrated that XIST was highly expressed in patients with acute stage of pneumonia. Knockdown of XIST remarkably alleviated LPS-induced cell injury through increasing cell viability and inhibiting apoptosis and inflammatory cytokine levels through regulating JAK/STAT and NF-κB pathways.

Role of Long Noncoding RNAs and Circular RNAs in Nerve Regeneration

Nerve injuries may cause severe disability and affect the quality of life. It is of great importance to get a full understanding of the biological processes and molecular mechanisms underlying nerve injuries to find and target specific molecules for nerve regeneration. Numerous studies have shown that noncoding RNAs (ncRNAs) participate in diverse biological processes and diseases. Long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) are two major groups of ncRNAs, which attract growing attention. The altered expression patterns of lncRNAs and circRNAs following nerve injury suggest that these ncRNAs might be associated with nerve regeneration. This review will give a brief introduction of lncRNAs and circRNAs. We then summarize the current studies on lncRNAs and circRNAs following peripheral nerve injury and spinal cord injury (SCI). Typical lncRNAs and circRNAs are introduced to illustrate the diverse molecular mechanisms for nerve regeneration. In addition, we also discuss some issues to be addressed in future investigations on lncRNAs and circRNAs.

Long non-coding RNA XIST promotes extracellular matrix degradation by functioning as a competing endogenous RNA of miR-1277-5p in osteoarthritis

Osteoarthritis (OA) is a common and troublesome disease among the elderly, and is characterized by extracellular matrix (ECM) degradation. The function of the long non‑coding RNA X‑inactive‑specific transcript (XIST) and its working mechanism in ECM degradation remains unclear. In the present study, XIST was revealed to be upregulated in OA specimens and in articular chondrocytes (ACs) derived from OA tissue (AC/OA) and interleukin‑1β (IL‑1β)‑treated ACs. Loss‑of‑function experiments demonstrated that downregulation of XIST suppressed the degradation of the ECM in AC/OA and AC/IL‑1β‑5.0 cells. Furthermore, XIST, matrix metalloproteinase 13 (MMP‑13) and ADAM metallopeptidase with thrombospondin type 1 motif 5 (ADAMTS5) were identified as targets of microRNA (miR)‑1277‑5p, and the reciprocal inhibitive effect between XIST and miR‑1277‑5p was elucidated. Furthermore, the role of XIST in ECM degradation was confirmed to be functioning as a competing endogenous RNA (ceRNA) of miR‑1277‑5p. Finally, the protective effect of the downregulation of XIST on ECM degradation was verified in an OA rat model. In conclusion, the present study suggests that XIST promotes MMP‑13 and ADAMTS5 expression, indicating ECM degradation, by functioning as a ceRNA of miR‑1277‑5p in OA. The present study proposed a novel potential target with a new working mechanism in molecular treating of OA.

Effect of M2 macrophage adoptive transfer on transcriptome profile of injured spinal cords in rats

The previous studies showed that alternatively activated anti-inflammatory macrophage (M2) adoptive immunity can improve the proportion of local M2 cells and play the neuroprotective effect after spinal cord injury (SCI). Its molecular mechanism is not yet very clear. Therefore, this study aims to analyze the effect of the M2 adoptive transfer on the local expression of gene transcription. Sprague-Dawley (SD) rats were used for culture of macrophages and establishment of SCI models. After SCI, the polarized M2 macrophages were transferred to the injured rats by tail vein injection. Seven days after operation, the differentially expressed genes (DEGs) in the spinal cords were analyzed by RNA-sequencing (RNA-Seq). Then, the functional enrichment analysis and pathways were performed by using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), respectively. RNA-Seq showed that M2 adoptive immunity can down-regulate many well-studied gene expressions associated with signaling pathways of inflammatory, such as antigen processing and presentation, phagosome, cell adhesion molecules, natural killer cell-mediated cytotoxicity, endocytosis, proteasome, and Toll-like receptor signaling pathway. These may explain the mechanism of our previous adoptive immunization of M2 cells to provide neuroprotection for SCI. In addition, a novel pathway, retinoic acid-inducible gene-1 (RIG-I)-like receptor signaling pathway was found to be involved in the pathological process of SCI and the response to M2 adoptive immunity as well. This will provide a new explanation for the pathological mechanism of SCI and a new theoretical and experimental basis for its clinical treatment. The raw Illumina data are available at http://www.ncbi.nlm.nih.gov/sra (accession number PRJNA517238).

Impact statement

This research aimed to analyze the effect of M2 macrophage adoptive transfer on the local expression of gene transcription after SCI by RNA-Seq. The results showed that M2 adoptive immunity can down-regulate many well-studied gene expressions associated with signaling pathways of inflammatory. These may explain the mechanism of our previous adoptive immunization of M2 cells to provide neuroprotection for SCI. In addition, a novel pathway, RIG-I-like receptor signaling pathway was also found to involve in the pathological process of SCI and the response to M2 adoptive immunity. This will provide a new explanation for the pathological mechanism of SCI and a new theoretical and experimental basis for its clinical treatment.

Overexpression of lncRNA TCTN2 protects neurons from apoptosis by enhancing cell autophagy in spinal cord injury

Neuronal apoptosis is the main pathological feature of spinal cord injury (SCI), while autophagy contributes to ameliorating neuronal damage via inhibition of apoptosis. Here, we investigated the role of tectonic family member 2 (TCTN2) long non-coding RNA on apoptosis and autophagy in SCI. TCTN2 was down-regulated in the spinal cord tissues of a rat model of SCI and in oxygen-glucose deprivation-induced hypoxic SY-SH-5Y cells, while microRNA-216b (miR-216b) was up-regulated. Overexpression of TCTN2 reduced neuron apoptosis by inducing autophagy, and TCTN2 was observed to negatively regulate miR-216b. Furthermore, TCTN2 promoted autophagy to repress apoptosis through the miR-216b-Beclin-1 pathway, and overexpression of TCTN2 improved neurological function in the SCI rat model. In summary, our data suggest that TCTN2 enhances autophagy by targeting the miR-216b-Beclin-1 pathway, thereby ameliorating neuronal apoptosis and relieving spinal cord injury.

Long non-coding RNAs in the spinal cord injury: Novel spotlight

Spinal cord injury (SCI) may lead to persistent locomotor dysfunction and somatosensory disorders, which adversely affect the quality of life of patients and cause a significant economic burden to the society. The efficacies of current therapeutic interventions are still far from satisfaction as the secondary damages resulting from the complex and progressive molecular alterations after SCI are not properly addressed. Recent studies revealed that long non‐coding RNAs (lncRNAs) are abundant in the brain and might play critical roles in several nervous system disorders. At the cellular level, lncRNAs have been shown to regulate the expression of protein‐coding RNAs and hence participate in neuronal death, demyelination and glia activation. Notably, SCI is characterized by these biological processes, suggesting that lncRNAs could be novel modulators in the pathogenesis of SCI. This review describes recent progresses in the lncRNA transcriptome analyses and their molecular functions in regulating SCI progression.

Functional roles of lncRNAs and its potential mechanisms in neuropathic pain

Neuropathic pain (NP) is ranked as one of the major forms of chronic pain and emerges as a direct consequence of a lesion or disease affecting the somatosensory nervous system. Despite great advances into the mechanisms of NP, clinical practice is still not satisfactory. Fortunately, progress in elucidating unique features and multiple molecular mechanisms of long non-coding RNAs (lncRNAs) in NP has emerged in the past 10 years, suggesting that novel therapeutic strategies for pain treatment may be proposed. In this review, we will concentrate on recent studies associated with lncRNAs in NP. First, we will describe the alterations of lncRNA expression after spinal cord injury (SCI) and peripheral nerve injury (PNI), and then we illustrate the role of some specific lncRNAs in detail, which may offer new insights into our understanding of the etiology and pathophysiology of NP. Finally, we put special emphasis on the altered expression of lncRNAs in the diverse biological process of NP. Recent advances we summarized above in the development of NP may facilitate translation of these findings from bench to bedside in the future.

A Novel lncRNA Regulates the Toll-Like Receptor Signaling Pathway and Related Immune Function by Stabilizing FOS mRNA as a Competitive Endogenous RNA

Long non-coding RNAs (lncRNAs) have recently emerged as new regulatory molecules with diverse functions in regulating gene expression and significant roles in the immune response. However, the function of many unknown lncRNAs is still unclear. By studying the regulatory effect of daidzein (DA) on immunity, we identified a novel lncRNA with an immune regulatory function: lncRNA- XLOC_098131. In vivo, DA treatment upregulated the expression of lncRNA- XLOC_098131, FOS, and JUN in chickens and affected the expression of activator protein 1 (AP-1) to regulate MAPK signaling, Toll-like receptor signaling, and related mRNA expression. It also enhanced macrophage activity and increased the numbers of blood neutrophils and mononuclear cells, which can improve the body's ability to respond to stress and bacterial and viral infections. Furthermore, DA treatment also reduced B lymphocyte apoptosis and promoted the differentiation of B lymphocytes into plasma cells, which in turn resulted in the production of more immunoglobulins and the promotion of antigen presentation. In vitro, using HEK293FT cells, we demonstrated that mir-548s could bind to and decrease the expression of both FOS and lncRNA- XLOC_098131. LncRNA- XLOC_098131 served as a competitive endogenous RNA to stabilize FOS by competitively binding to miR-548s and thereby reducing its inhibitory effect of FOS expression. Therefore, we concluded that the novel lncRNA XLOC_098131 acts as a key regulatory molecule that can regulate the Toll-like receptor signaling pathway and related immune function by serving as a competitive endogenous RNA to stabilize FOS mRNA expression.

Construction and analysis of a spinal cord injury competitive endogenous RNA network based on the expression data of long noncoding, micro‑ and messenger RNAs

Spinal cord injury (SCI) results from trauma and predominantly affects the young male population. SCI imposes major and permanent life changes, and is associated with high future mortality and disability rates. Long non-coding RNAs (lncRNAs) have recently been demonstrated to serve critical roles in a broad range of biological processes and to be expressed in various diseases, including in SCI. However, the precise mechanisms underlying the roles of lncRNAs in SCI pathogenesis remain unexplored. In the present study, the aim was to identify critical differentially expressed lncRNAs in SCI based on the competing endogenous RNA (ceRNA) hypothesis by mining data from the Gene Expression Omnibus database of the National Center for Biotechnology Information and to unveil the functions of these lncRNAs. Different approaches and tools were employed to establish a network consisting of 13 lncRNA, 93 messenger RNA and 9 microRNA nodes, with a total of 202 edges. Three node lncRNAs were identified based on the degree distribution of the nodes, and their corresponding subnetworks were subsequently constructed. Based on these subnetworks, the biological pathways and interactions of these 3 lncRNAs were detailed using FunRich software (version 3.0). The primary results of the 3 lncRNA enrichment analyses were that they were associated with autophagy, extracellular communication and transcription factor networks, respectively. The phosphoinositide 3‑kinase/protein kinase B/mammalian target of rapamycin signaling pathway of XR_350851 was the classic autophagy pathway, indicating that XR_350851 may regulate autophagy in SCI. The possible role of XR_350851 in SCI revealed in the current study based on the regulatory mechanism of ceRNAs has uncovered a new repertoire of molecular factors with potential as novel biomarkers and therapeutic targets in SCI.

Long non-coding PCED1B-AS1 regulates macrophage apoptosis and autophagy by sponging miR-155 in active tuberculosis

Macrophages play a major role in the control and elimination of invading Mycobacterium tuberculosis (Mtb). Emerging studies have demonstrated that long non-coding RNAs (lncRNAs) are involved in resident macrophages in Mtb. However, the regulatory mechanism between lncRNAs and macrophages in tuberculosis (TB) remains unclear. In this study, we sought to investigate the effect of Mtb-associated lncRNA PCED1B-AS1 on macrophage apoptosis and autophagy. Our study first evaluated PCED1B-AS1 expression in the CD14⁺ monocytes from patients with active tuberculosis and from healthy individuals. It was found that PCED1B-AS1 expression was down-regulated in patients with active tuberculosis, accompanied by significant attenuated monocyte apoptosis and enhanced autophagy. In vitro, knockdown of PCED1B-AS1 reduced macrophage apoptosis and promoted autophagy. PCED1B-AS1 serves as an endogenous sponge to block miR-155 expression in macrophages by directly binding to miR-155. Furthermore, we demonstrated that overexpression of FOXO3/Rheb, target genes of miR-155, reversed the PCED1B-AS1-mediated effects on macrophage apoptosis and autophagy. Altogether, our data indicate that PCED1B-AS1 modulates macrophage apoptosis and autophagy by targeting the miR-155 axis in active TB.

Neuroprotective effects of rapamycin on spinal cord injury in rats by increasing autophagy and Akt signaling

Rapamycin treatment has been shown to increase autophagy activity and activate Akt phosphorylation, suppressing apoptosis in several models of ischemia reperfusion injury. However, little has been studied on the neuroprotective effects on spinal cord injury by activating Akt phosphorylation. We hypothesized that both effects of rapamycin, the increased autophagy activity and Akt signaling, would contribute to its neuroprotective properties. In this study, a compressive spinal cord injury model of rat was created by an aneurysm clip with a 30 g closing force. Rat models were intraperitoneally injected with rapamycin 1 mg/kg, followed by autophagy inhibitor 3-methyladenine 2.5 mg/kg and Akt inhibitor IV 1 µg/kg. Western blot assay, immunofluorescence staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay were used to observe the expression of neuronal autophagy molecule Beclin 1, apoptosis-related molecules Bcl-2, Bax, cytochrome c, caspase-3 and Akt signaling. Our results demonstrated that rapamycin inhibited the expression of mTOR in injured spinal cord tissue and up-regulated the expression of Beclin 1 and phosphorylated-Akt. Rapamycin prevented the decrease of bcl-2 expression in injured spinal cord tissue, reduced Bax, cytochrome c and caspase-3 expression levels and reduced the number of apoptotic neurons in injured spinal cord tissue 24 hours after spinal cord injury. 3-Methyladenine and Akt inhibitor IV intervention suppressed the expression of Beclin-1 and phosphorylated-Akt in injured spinal cord tissue and reduced the protective effect of rapamycin on apoptotic neurons. The above results indicate that the neuroprotective effect of rapamycin on spinal cord injury rats can be achieved by activating autophagy and the Akt signaling pathway.

LncRNA XIST regulates myocardial infarction by targeting miR-130a-3p

The study was used to probe long noncoding RNA X-inactive specific transcript (lncRNA XIST) RNA expression profile and its influence on cell cycle, proliferation, and apoptosis in myocardial cells. We also aimed to explore the possible meditating relationship between XIST, PDE4D, and miR-130a-3p. Gene differential analysis was carried out using human lncRNA Microarray V3.0. quantitative real-time PCR was used to test mRNA expressions of XIST, miR-130a-3p, and PDE4D in normal cells and postmyocardial infarction (MI) cells. Western blot was applied to determine the protein expression profile of PED4D. Changes in viability and cell cycle/apoptosis of post-MI myocardial cells after silencing of XIST or PDE4D were investigated by MTT assay and flow cytometry, respectively. The targeting relationship between miR-130a-3p and XIST, PDE4D in myocardial cells were verified by dual luciferase reporter assay. Simulated MI environment was constructed by performing anoxic preconditioning in normal cells to probe the influence of XIST on myocardial cell apoptosis. XIST and PDE4D were overexpressed in post-MI myocardial cells, whereas miR-130a-3p was underexpressed in post-MI myocardial cells. High-expressed XIST and PDE4D both promoted myocardial cell apoptosis. High-expressed XIST also inhibited myocardial cell proliferation. XIST-downregulated miR-130a-3p and PDE4D was a direct target of miR-130a-3p. LncRNA XIST promotes MI by targeting miR-130a-3p. MI induced by PDE4D can be reversed by miR-130a-3p.

Role of lncRNA and EZH2 Interaction/Regulatory Network in Lung Cancer

Lung cancer is the leading cause of cancer-related deaths worldwide. Long non-coding RNAs (lncRNAs) are non-protein-coding transcripts and longer than 200 nucleotides. LncRNAs have been demonstrated to modulate gene expression at transcriptional, post-transcriptional, as well as epigenetic levels in lung cancer. Interestingly, compelling studies have revealed that lncRNAs participated in the EZH2 oncogenic regulatory network. EZH2 plays an important role in the initiation, progression and metastasis of cancer. On one hand, lncRNAs can directly bind to EZH2, recruit EZH2 to the promoter region of genes and repress their expression. On the other hand, lncRNAs can also serve as EZH2 effectors or regulators. In this review, we summarized the types of lncRNA-EZH2 interaction and regulatory network identified till date and discussed their influence on lung cancer. Better understanding regarding the interaction and regulatory network will provide new insights on lncRNA- or EZH2-based therapeutic development in lung cancer.

The long noncoding RNA XIST protects cardiomyocyte hypertrophy by targeting miR-330-3p

Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are implicated in numerous kinds of cardiovascular diseases, and their vital role in regulating cardiac hypertrophy still needs to be explored. In this study, we demonstrated that lncRNA X-inactive specific transcript (XIST) was upregulated in hypertrophic cardiac of mice and phenylephrine (PE)-treated cardiomyocytes. Next, we observed that inhibition of XIST induced hypertrophic response of cardiomyocyte and overexpression of XIST attenuated cardiomyocyte hypertrophy induced by PE. Furthermore, through online predictive tools and functional experiments, we demonstrated that XIST and S100B were targets of miR-330-3p. XIST and miR-330-3p suppressed each other in a reciprocal way in cardiomyocytes. Additionally, XIST promoted S100B expression through harboring the complementary binding sites with miR-330-3p, eventually prevented cardiac hypertrophy. In conclusion, our findings revealed a novel molecular mechanism that XIST/miR-330-3p/S100B pathway modulates the progression of cardiomyocyte hypertrophy.

LncRNA DGCR5 suppresses neuronal apoptosis to improve acute spinal cord injury through targeting PRDM5

Spinal cord injury (SCI) usually results in neurological damage. DGCR5 is closely related to neurological disorders, and this study aims to explore its role in neuronal apoptosis in acute SCI. The ASCI model was established in rats, and the Basso, Beattie, and Bresnahan (BBB) scoring was used to assess the neurological function. The expression of RNA and protein was quantified by quantitative real-time PCR (qRT-PCR) and western blotting, respectively. The oxygenglucose deprivation (OGD) was performed upon neurons and apoptosis was evaluated by flow cytometry. The interaction and binding between DGCR5 and PRDM5 was detected with RNA pull-down and RIP assay, respectively. DGCR5 was down-regulated in ASCI model rat and in neurons treated with hypoxia. Over-expression of DGCR5 inhibited neuronal apoptosis. Interaction between DGCR5 negatively regulated PRDM5 protein expression by binding and interacting with it. DGCR5 inhibited neuronal apoptosis through PRDM5. Over-expressed DGCR5 ameliorated ASCI in rat. DGCR5 suppresses neuronal apoptosis through directly binding and negatively regulating PRDM5, and thereby ameliorating ASCI.

Regulation of PTEN expression by noncoding RNAs

Phosphatase and tensin homologue (PTEN) triggers a battery of intracellular signaling pathways, especially PI3K/Akt, playing important roles in the pathogenesis of multiple diseases, such as cancer, neurodevelopmental disorders, cardiovascular dysfunction and so on. Therefore PTEN might be a biomarker for various diseases, and targeting the abnormal expression level of PTEN is anticipated to offer novel therapeutic avenues. Recently, noncoding RNAs (ncRNAs) have been reported to regulate protein expression, and it is definite that PTEN expression is controlled by ncRNAs epigenetically or posttranscriptionally as well. Herein, we provide a review on current understandings of the regulation of PTEN by ncRNAs, which could contribute to the development of novel approaches to the diseases with abnormal expression of PTEN.

Knockdown of lncRNA BDNF-AS suppresses neuronal cell apoptosis via downregulating miR-130b-5p target gene PRDM5 in acute spinal cord injury

OBJECTIVE

The present study was designed to investigate the molecular mechanism and biological roles of lncRNA brain-derived neurotrophic factor antisense (lncRNA BDNF-AS) in acute spinal cord injury (ASCI).

METHODS

The rat model of ASCI and hypoxic cellular model were established to detect the expression of BDNF-AS, miR-130b-5p, PR (PRDI-BF1 and RIZ) domain protein 5 (PRDM5) and cleaved caspase 3 (c-caspase 3) using qRT-PCR and western blot. Basso, Beattie and Bresnahan (BBB) score was carried out to assess neurological function. Flow cytometry was used to determine the apoptosis of neuronal cells. The association among BDNF-AS, miR-130b-5p and PRDM5 were disclosed by RNA immunoprecipitation (RIP) assay, RNA pull-down assay and dual-luciferase reporter assay.

RESULTS

BDNF-AS, PRDM5 and c-caspase 3 expression were significantly upregulated, while miR-130b-5p was suppressed in the ASCI group and neuronal cells following hypoxia treatment. BDNF-AS knockdown inhibited neuronal cell apoptosis. Further studies indicated that BDNF-AS functioned as a competing endogenous RNA (ceRNA) by sponging miR-130b-5p in neuronal cells. Further investigations demonstrated that PRDM5 was a target of miR-130b-5p and BDNF-AS knockdown exerted anti-apoptotic effects via miR-130b-5p/PRDM5 axis.

CONCLUSION

The lncRNA BDNF-AS/miR-130b-5p/PRDM5 axis might be a promising therapeutic target for ASCI.

Inhibition of lncRNA X inactivate-specific transcript ameliorates inflammatory pain by suppressing satellite glial cell activation and inflammation by acting as a sponge of miR-146a to inhibit Nav 1.7

Long noncoding RNAs (lncRNA) has been validated to participate in nociception in inflammatory pain, presenting as a potential target against anesthesia. Previous research work confirmed the correlation between lncRNA X inactivate-specific transcript (XIST) and inflammation. However, its role in inflammatory pain is undefined. In animal pain models, voltage-gated sodium channels (VGSCs) reportedly participate in neural excitation. In this study, we observed the high expression of XIST and VGSC 1.7 (Na_v 1.7) in the dorsal root ganglion (DRG) of the complete Freund's adjuvant (CFA)-induced rat inflammatory pain model. Furthermore, XIST inhibition alleviated pain behavior and the activation of DRG satellite glial cells by suppressing glial fibrillary acidic protein (GFAP) expression, as well as inflammatory cytokine levels of interleukin-6 and tumor necrosis factor-α. XIST downregulation increased the mechanical pain threshold in an inflammatory pain model. Moreover, the expression of miR-146a was decreased in CFA rats. In vitro, XIST acted as a sponge of miR-146a, which targeted Na_v 1.7 via bioinformatic prediction, luciferase reporter, and pull-down assay. More importantly, activation of the Na_v 1.7 pathway or miR-146 depression both reversed XIST knockdown-inhibited satellite glial cell activation and inflammatory pain in CFA rats. These results suggest that cessation of XIST may ameliorate inflammatory pain by acting as a sponge of miR-146a to inhibit Nav1.7, implying a promising strategy against inflammatory pain.

LncRNA XIST knockdown attenuates Aβ25-35-induced toxicity, oxidative stress, and apoptosis in primary cultured rat hippocampal neurons by targeting miR-132

Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative disorder. The abnormal accumulation and deposition of amyloid-beta peptide (Aβ) in senile plaques and cerebral vasculature is widely recognized to be the most likely culprit in the pathogenesis of AD. Long non-coding RNAs (lncRNAs), a kind of evolutionarily conserved non-coding RNAs with over 200 nucleotides in length, have introduced a novel field of biology, and are involved in various human diseases, including neurological diseases. Recently, lncRNA X-inactive specific transcript (XIST) is reported to be upregulated in the rat spinal cord injury (a neurological disease) model and XIST knockdown has a prominent protective effect on the recovery of spinal cord injury. However, little is known about the expression and function of XIST in AD. Here, we showed that Aβ_25-35 treatment increased XIST expression in hippocampal neurons. XIST knockdown ameliorated toxicity, oxidative stress, and apoptosis induced by Aβ_25-35 treatment in hippocampal neurons. We further identified and confirmed that miR-132 was the target of XIST, and XIST functioned by targeting miR-132. Collectively, these data show that knockdown of XIST relieves Aβ_25-35-induced toxicity, oxidative stress, and apoptosis in primary cultured rat hippocampal neurons by upregulation of miR-132. These findings encourage continued investigation of the potential of manipulating XIST in the treatment of AD.

LncRNA SNHG5 enhances astrocytes and microglia viability via upregulating KLF4 in spinal cord injury

This study aims to explore the role and mechanism of lncRNA SNHG5 in spinal cord injury (SCI). The interaction between SNHG5 and Krüppel-like factor 4 (KLF4) was verified by RNA pull-down and RNA immunoprecipitation (RIP) assay. Rat neural function was evaluated by BBB and BMS scores. Results showed that GFAP and Iba-1 (specific proteins for astrocytes and microglia respectively) were upregulated in spinal cord of SCI rats. Simultaneously, spinal cord also expressed substantially higher levels of SNHG5, KLF4 and eNOS (endothelial Nitric Oxide Synthase) than sham group. In traumatically injured astrocytes and microglia, SNHG5 overexpression increased cells viability, which was significantly inhibited by SNHG5 knockdown. KLF4 is a directly target for SNHG5 and is positively regulated by SNHG5. The knockdown of KLF4 effectively decreased astrocytes and microglia viability induced by SHNG5 overexpression and attenuated the pcDNA-SNHG5-mediated repression of the apoptosis. In SCI rats, the injection of Lenti-SNHG5 reduced BBB and BMS scores and also enhanced the protein expression of KLF4, eNOS, GFAP and Iba-1. In summary, our data suggested that SNHG5 promotes SCI via increasing the viability of astrocytes and microglia. The mechanism by which SNHG5 works is its directive interaction to KLF4 and contribution to eNOS upregulation.

MicroRNA-based therapeutics in central nervous system injuries

Central nervous system (CNS) injuries, such as stroke, traumatic brain injury (TBI) and spinal cord injury (SCI), are important causes of death and long-term disability worldwide. MicroRNA (miRNA), small non-coding RNA molecules that negatively regulate gene expression, can serve as diagnostic biomarkers and are emerging as novel therapeutic targets for CNS injuries. MiRNA-based therapeutics include miRNA mimics and inhibitors (antagomiRs) to respectively decrease and increase the expression of target genes. In this review, we summarize current miRNA-based therapeutic applications in stroke, TBI and SCI. Administration methods, time windows and dosage for effective delivery of miRNA-based drugs into CNS are discussed. The underlying mechanisms of miRNA-based therapeutics are reviewed including oxidative stress, inflammation, apoptosis, blood-brain barrier protection, angiogenesis and neurogenesis. Pharmacological agents that protect against CNS injuries by targeting specific miRNAs are presented along with the challenges and therapeutic potential of miRNA-based therapies.

Knockdown of long noncoding RNA XIST alleviates oxidative low-density lipoprotein-mediated endothelial cells injury through modulation of miR-320/NOD2 axis

Atherosclerosis remains to be one of the most common vascular disorders resulting in morbidity and mortality in the world. Recent studies suggested that endothelial cells (ECs) injury caused by oxidative low-density lipoprotein (ox-LDL) is an early marker for atherosclerosis. Nevertheless, the mechanisms of ox-LDL-induced ECs injury are complicated and largely unknown. Here, we found lncRNA XIST (X-inactive specific transcript) was upregulated in human umbilical vein endothelial cells (HUVECs) stimulated by ox-LDL. Knockdown of XIST boosted the cell viability and suppressed cell apoptosis under ox-LDL stimuli. Further experiments identified XIST regulated the expression of Nucleotide-Binding Oligomerization Domain 2 (NOD2) by sponging miR-320. XIST silencing exerted a protective effect on ox-LDL-induced HUVECs injury via miR-320/NOD2 regulatory network. Our data provide insight into the role of the lncRNA XIST in ox-LDL mediated ECs injury, which can aid in developing new therapeutic strategies for the treatment of atherosclerosis.

XIST/miR-544 axis induces neuropathic pain by activating STAT3 in a rat model

An increasing number of studies have reported that lncRNAs are responsible for the development of neuropathic pain. In our current study, chronic constriction injury (CCI) rat models were established and we observed that lncRNA XIST was greatly increased. Knockdown of XIST can relieve pain characteristics including both mechanical and thermal hyperalgesia in CCI rats. Meanwhile, XIST down-regulation could inhibit neuro-inflammation by reducing expression of inflammatory cytokines including tumor necrosis factor (TNF)-α, IL-1β, and IL-6 and in CCI rats. By performing bioinformatics technology, miR-544 was predicted to have interactions with XIST and dual-luciferase reporter assays validated the correlation between them. A negative correlation between miR-544 and XIST was observed by carrying out XIST loss or gain of function tests. miR-544 markedly alleviated neuropathic pain development in CCI rats via targeting inflammatory cytokines, which was reversed by XIST over-expression. Moreover, STAT3 was manifested to be a target gene of miR-544 by bioinformatics predictions and it was activated in CCI rats. Over-expression of STAT3 was able to induce neuropathic pain and miR-544 inhibited this process in vivo. Furthermore, XIST increased STAT3 expression by sponging miR-544 in neuropathic pain development. To conclude, our present study indicated that XIST can contribute to neuropathic pain progression in rats through down-regulating miR-544 and up-regulating STAT3. Our results suggested that XIST/miR-544/STAT3 axis can serve as a novel therapeutic target in neuropathic pain development.

Lipoxin A4 protects against spinal cord injury via regulating Akt/nuclear factor (erythroid-derived 2)-like 2/heme oxygenase-1 signaling

Spinal cord injury (SCI) is a devastating physical trauma worldwide. The mechanisms of SCI are still not clear and the effective treatment is limited. Lipoxin A4 (LXA4) possesses anti-inflammatory and neuroprotective effects. The present study was designed to further evaluate the molecular mechanisms of LXA4-induced protective effects in a rat model of SCI. We found that LXA4 increased Basso, Beattie and Bresnahan (BBB) scores, increased mechanical paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) to a radiant heat, reduced the lesion volume, decreased Bax mRNA expression and increased Bcl-2 expression after SCI. The phosphorylation of Akt and protein expression of Nrf2 and HO-1 were reduced after SCI. LXA4 treatment significantly inhibited the reduction of Akt phosphorylation and Nrf2 and HO-1 protein expression. Injection of LY294002 notably inhibited the phosphorylation of Akt, and the expression of total Akt and Nrf2 and HO-1 after SCI in LXA4-treated rats. LY294002 prohibited LXA4-induced effects after SCI. shNrf2 injection markedly decreased both Nrf2 and HO-1 expression in LXA4-treated rats after SCI. ZnPP notably decreased HO-1 expression but did not markedly affect Nrf2 expression. shNrf2 and ZnPP prohibited LXA4-induced increase of BBB scores, and PWT and PWL, decrease of lesion volume of spinal cord, reduction of Bax expression and increase of Bcl-2 expression. The results indicate that LXA4 protects against SCI through Akt/Nrf2/HO-1 signaling. The data provide novel insights into the mechanisms of LXA4-mediated neuprotective effects against SCI and suggest that LXA4 may be a potential therapeutic agent for SCI and its associated complications.

Trends of long noncoding RNA research from 2007 to 2016: a bibliometric analysis

Purpose

This study aims to analyze the scientific output of long noncoding RNA (lncRNA) research and construct a model to evaluate publications from the past decade qualitatively and quantitatively.

Methods

Publications from 2007 to 2016 were retrieved from the Web of Science Core Collection database. Microsoft Excel 2016 and CiteSpace IV software were used to analyze publication outputs, journals, countries, institutions, authors, citation counts, ESI top papers, H-index, and research frontiers.

Results

A total of 3,008 papers on lncRNA research were identified published by June 17, 2017. The journal, Oncotarget (IF2016, 5.168) ranked first in the number of publications. China had the largest number of publications (1,843), but the United States showed its dominant position in both citation frequency (45,120) and H-index (97). Zhang Y (72 publications) published the most papers, and Guttman M (1,556 citations) had the greatest co-citation counts. The keyword “database” ranked first in research frontiers.

Conclusion

The annual number of publications rapidly increased in the past decade. China showed its significant progress in lncRNA research, but the United States was the actual leading country in this field. Many Chinese institutions engaged in lncRNA research but significant collaborations among them were not noted. Guttman M, Mercer TR, Rinn JL, and Gupta RA were identified as good candidates for research collaboration. “Database,” “Xist RNA,” and “Genome-wide association study” should be closely observed in this field.

Functional integration of complex miRNA networks in central and peripheral lesion and axonal regeneration

New players are emerging in the game of peripheral and central nervous system injury since their physiopathological mechanisms remain partially elusive. These mechanisms are characterized by several molecules whose activation and/or modification following a trauma is often controlled at transcriptional level. In this scenario, microRNAs (miRNAs/miRs) have been identified as main actors in coordinating important molecular pathways in nerve or spinal cord injury (SCI). miRNAs are small non-coding RNAs whose functionality at network level is now emerging as a new level of complexity. Indeed they can act as an organized network to provide a precise control of several biological processes. Here we describe the functional synergy of some miRNAs in case of SCI and peripheral damage. In particular we show how several small RNAs can cooperate in influencing simultaneously the molecular pathways orchestrating axon regeneration, inflammation, apoptosis and remyelination. We report about the networks for which miRNA-target bindings have been experimentally demonstrated or inferred based on target prediction data: in both cases, the connection between one miRNA and its downstream pathway is derived from a validated observation or is predicted from the literature. Hence, we discuss the importance of miRNAs in some pathological processes focusing on their functional structure as participating in a cooperative and/or convergence network.