Emerging roles of long non-coding RNAs in neuropathic pain

Study on analgesic effect of Shentong Zhuyu Decoction in neuropathic pain rats by network pharmacology and RNA-Seq

ETHNOPHARMACOLOGICAL RELEVANCE

Shentong Zhuyu Decoction (STZYD) is a traditional prescription for promoting the flow of Qi and Blood which is often used in the treatment of low back and leg pain clinicall with unclear mechanism. Neuropathic pain (NP) is caused by disease or injury affecting the somatosensory system. LncRNAs may play a key role in NP by regulating the expression of pain-related genes through binding mRNAs or miRNAs sponge mechanisms.

AIM OF THE STUDY

To investigate the effect and potential mechanism of STZYD on neuropathic pain.

METHODS

Chronic constriction injury (CCI) rats, a commonly used animal model, were used in this study. The target of STZYD in NP was analyzed by network pharmacology, and the analgesic effect of STZYD in different doses (H-STZYD, M-STZYD, L-STZYD) on CCI rats was evaluated by Mechanical withdrawal thresholds (MWT) and thermal withdrawal latency (TWL). Meanwhile, RNA-seq assay was used to detect the changed mRNAs and lncRNAs in CCI rats after STZYD intervention. GO analysis, KEGG pathway analysis, and IPA analysis were used to find key target genes and pathways, verified by qPCR and Western Blot. The regulatory effect of lncRNAs on target genes was predicted by co-expression analysis and ceRNA network construction.

RESULTS

We found that STZYD can improve hyperalgesia in CCI rats, and H-STZYD has the best analgesic effect. The results of network pharmacological analysis showed that STZYD could play an analgesic role in CCI rats through the MAPK/ERK/c-FOS pathway. By mRNA-seq and lncRNA-seq, we found that STZYD could regulate the expression of Cnr1, Cacng5, Gucy1a3, Kitlg, Npy2r, and Grm8, and inhibited the phosphorylation level of ERK in the spinal cord of CCI rats. A total of 27 lncRNAs were associated with the target genes and 30 lncRNAs, 83 miRNAs and 5 mRNAs participated in the ceRNA network.

CONCLUSION

STZYD has the effect of improving hyperalgesia in CCI rats through the MAPK/ERK/c-FOS pathway, which is related to the regulation of lncRNAs to Cnr1 and other key targets.

Alteration in the expression of long non-coding RNAs in the circulation of migraineurs

BACKGROUND

Current studies have shown emerging roles of lncRNAs in the pathobiology of neuropathic pain and migraine.

METHODS

We have chosen five lncRNAs, namely, PVT1, DSCAM-AS, MEG3, LINC-ROR, and SPRY4-IT1 for assessment of their expression in the circulation of migraineurs.

RESULTS

Expressions of PVT1 and MEG3 were higher in total migraineurs and both subgroups compared with controls (P < 0.0001). Meanwhile, expression of both lncRNA was higher in migraineurs with aura versus migraineurs without aura (P value < 0.0001 and = 0.01, respectively). Expression of DSCAM-AS1 was not different between any groups of patients compared with controls. Expression of LINC-ROR was elevated in total patients and patients with aura compared with controls (P value = 0.0002 and < 0.0001, respectively). It was also over-expressed in migraineurs with aura vs. migraineurs without aura (P = 0.01). Finally, expression of SPRY4-IT1 was higher in total patients and patients without aura compared with migraine-free persons (P values < 0.0001). Expressions of five mentioned lncRNAs were correlated in almost all study groups. In patients without aura, correlations were significant only for two pairs (SPRY4-IT1/PVT1 and SPRY4-IT1/DSCAM-AS1). PVT1 and MEG3 had the appropriate AUC, sensitivity and specificity values for separation of total migraineurs and both groups of patients from controls. The highest AUC value was reported for PVT1 in separation of migraineurs with aura from healthy controls (AUC = 0.98).

CONCLUSION

Cumulatively, our study shows evidence for deregulation of lncRNAs in migraineurs.

The role of non-coding RNAs in neuropathic pain

Neuropathic pain (NPP) is a refractory pain syndrome, caused by damage or disease of the somatosensory nervous system and characterized by spontaneous pain, hyperalgesia, abnormal pain and sensory abnormality. Non-coding RNAs (ncRNAs), including microRNA (miRNA), long non-coding RNA (lncRNA), circular RNA (circRNA) and Piwi interacting RNA (piRNA), play a notable role in initiation and maintenance of NPP. In this review, we summarize the role of ncRNAs in NPP and their underlaying mechanism. Generally, ncRNAs are interacted with mRNA, protein or DNA to regulate the molecules and signals assciated with neuroinflammation, ion channels, neurotrophic factors and others, and then involved in the occurrence and development of NPP. Therefore, this review not only contributes to deepen our understanding of the pathophysiological mechanism of NPP, but also provides theoretical basis for the development of new therapy strategies for this disorder.

Metabolic memory: mechanisms and diseases

Metabolic diseases and their complications impose health and economic burdens worldwide. Evidence from past experimental studies and clinical trials suggests our body may have the ability to remember the past metabolic environment, such as hyperglycemia or hyperlipidemia, thus leading to chronic inflammatory disorders and other diseases even after the elimination of these metabolic environments. The long-term effects of that aberrant metabolism on the body have been summarized as metabolic memory and are found to assume a crucial role in states of health and disease. Multiple molecular mechanisms collectively participate in metabolic memory management, resulting in different cellular alterations as well as tissue and organ dysfunctions, culminating in disease progression and even affecting offspring. The elucidation and expansion of the concept of metabolic memory provides more comprehensive insight into pathogenic mechanisms underlying metabolic diseases and complications and promises to be a new target in disease detection and management. Here, we retrace the history of relevant research on metabolic memory and summarize its salient characteristics. We provide a detailed discussion of the mechanisms by which metabolic memory may be involved in disease development at molecular, cellular, and organ levels, with emphasis on the impact of epigenetic modulations. Finally, we present some of the pivotal findings arguing in favor of targeting metabolic memory to develop therapeutic strategies for metabolic diseases and provide the latest reflections on the consequences of metabolic memory as well as their implications for human health and diseases.

Circulating Levels of HOTAIR- lncRNA Are Associated with Disease Progression and Clinical Parameters in Type 2 Diabetes Patients

Background

Recent studies have implicated dysregulated long non-coding RNA (lncRNA) levels in the pathogenesis of type 2 diabetes (T2D). This study aimed to assess the expression of circulating HOTAIR and uc.48+, examining their correlation with clinical and biochemical variables in T2D patients, pre-diabetic individuals, and healthy controls.

Methods

Peripheral blood levels of lncRNAs were quantified using QRT-PCR in 65 T2D patients, 63 pre-diabetic individuals, and 63 healthy subjects. Pathway enrichment analysis was conducted to explore the functional enrichment of lncRNA-miRNA targets.

Results

Analysis revealed a significantly elevated circulating level of HOTAIR in both T2D (P < 0.0001) and pre-diabetic patients (P = 0.04) compared to controls. ROC analysis demonstrated that, at a cutoff value of 9.1, with a sensitivity of 80% and specificity of 62%, HOTAIR could distinguish T2D patients from controls (AUC = 0.723, 95% CI 0.637-0.799, P < 0.0001). Spearman correlation analysis identified a significant positive correlation between HOTAIR expression, HbA1c, and insulin resistance (P < 0.005). MiRNA enrichment analysis indicated significant enrichment of diabetes-related pathways among HOTAIR's miRNA targets. Conversely, no significant difference in uc.48+ circulating levels between groups was observed, but a significant positive correlation emerged between uc.48+ and systolic blood pressure.

Conclusions

This study provides evidence that elevated HOTAIR expression levels are associated with T2D progression, suggesting their potential as biomarkers for early diagnosis and prognosis.

LncRNA MAFG-AS1-induced acute myeloid leukemia development via modulating miR-147b/HOXA9

Recent references discovered that lncRNAs acted roles in malignant cancer development. However, the role of MAFG-AS1 in acute myeloid leukemia (AML) development remains unknown. MAFG-AS1 and miR-147b were determined in AML cells and specimens using qRT-PCR assay. Cell proliferation was detected by CCK-8 analysis and flow cytometry was carried out to measure cell cycle. Luciferase reporter analysis was done to determine the mechanism of MAFG-AS1 and miR-147b. We noted that MAFG-AS1 was overexpressed in AML cells and in serum and bone narrow from AML compared with normal controls specimen. Elevated expression of MAFG-AS1 increased cell growth, cycle and EMT in AML cell HL-60 cell. MAFG-AS1 sponged miR-147b expression in HL-60 cell. Moreover, miR-147b was downregulated in AML cells and in serum and bone narrow from AML compared with normal control specimen. miR-147b was negatively correlated with MAFG-AS1 in the serum and bone narrow of AML cases. We illustrated that HOXA9 was one target of miR-147b and ectopic expression of MAFG-AS1 enhanced HOXA9 expression HL-60 cell. Forced expression of MAFG-AS1 induced cell growth, cycle, and EMT via promoting HOXA9. These data illustrated that MAFG-AS1 acted as one oncogenic gene and accelerated AML progression via modulating miR-147b/HOXA9 axis.

Global research trends on epigenetics and neuropathic pain: A bibliometric analysis

Objective

Neuropathic pain (NP) is a common disease that manifests with pathological changes in the somatosensory system. In recent years, the interactions of NP with the epigenetic mechanism have been increasingly elucidated. However, only a few studies have used bibliometric tools to systematically analyze knowledge in this field. The objective of this study is to visually analyze the trends, hotspots, and frontiers in epigenetics and NP research by using a bibliometric method.

Methods

Studies related to epigenetics and NP were searched from the Science Citation Index-Expanded of the Web of Science Core Collection database. Search time is from inception to November 30, 2022. No restrictions were placed on language. Only articles and reviews were included as document types. Data on institutions, countries, authors, journal distribution, and keywords were imported into CiteSpace software for visual analysis.

Results

A total of 867 publications met the inclusion criteria, which spanned the period from 2000 to 2022. Over the years, the number of publications and the frequency of citations exhibited a clear upward trend in general, reaching a peak in 2021. The major contributing countries in terms of the number of publications were China, the United States, and Japan. The top three institutions were Rutgers State University, Xuzhou Medical University, and Nanjing Medical University. Molecular Pain, Pain, and Journal of Neuroinflammation contributed significantly to the volume of issues. Among the top 10 authors in terms of the number of publications, Tao Yuan-Xiang contributed 30 entries, followed by Zhang Yi with 24 and Wu Shao-Gen with 20. On the basis of the burst and clusters of keywords, "DNA methylation," "Circular RNA," "acetylation," "long non-coding RNA," and "microglia" are global hotspots in the field.

Conclusion

The bibliometric analysis indicates that the number of publications related to epigenetics and NP is exhibiting a rapid increase. Keyword analysis shows that "DNA methylation," "Circular RNA," "acetylation," "long non-coding RNA" and "microglia" are the most interesting terms for researchers in the field. More rigorous clinical trials and additional studies that explore relevant mechanisms are required in the future.

Upregulation of LncRNA71132 in the spinal cord regulates hypersensitivity in a rat model of bone cancer pain

ABSTRACT

Bone cancer pain (BCP) is a pervasive clinical symptom which impairs the quality life. Long noncoding RNAs (lncRNAs) are enriched in the central nervous system and play indispensable roles in numerous biological processes, while its regulatory function in nociceptive information processing remains elusive. Here, we reported that functional modulatory role of ENSRNOT00000071132 (lncRNA71132) in the BCP process and sponging with miR-143 and its downstream GPR85-dependent signaling cascade. Spinal lncRNA71132 was remarkably increased in the rat model of bone cancer pain. The knockdown of spinal lncRNA71132 reverted BCP behaviors and spinal c-Fos neuronal sensitization. Overexpression of spinal lncRNA71132 in naive rat generated pain behaviors, which were accompanied by increased spinal c-Fos neuronal sensitization. Furthermore, it was found that lncRNA71132 participates in the modulation of BCP by inversely regulating the processing of miR-143-5p. In addition, an increase in expression of spinal lncRNA71132 resulted in the decrease in expression of miR-143 under the BCP state. Finally, it was found that miR-143-5p regulates pain behaviors by targeting GPR85. Overexpression of miR-143-5p in the spinal cord reverted the nociceptive behaviors triggered by BCP, accompanied by a decrease in expression of spinal GPR85 protein, but no influence on expression of gpr85 mRNA. The findings of this study indicate that lncRNA71132 works as a miRNA sponge in miR-143-5p-mediated posttranscriptional modulation of GPR85 expression in BCP. Therefore, epigenetic interventions against lncRNA71132 may potentially work as novel treatment avenues in treating nociceptive hypersensitivity triggered by bone cancer.

Derivation of nociceptive sensory neurons from hiPSCs with early patterning and temporally controlled NEUROG2 overexpression

Despite development of protocols to differentiate human pluripotent stem cells (hPSCs), those used to produce sensory neurons remain difficult to replicate and result in heterogenous populations. There is a growing clinical burden of chronic pain conditions, highlighting the need for relevant human cellular models. This study presents a hybrid differentiation method to produce nociceptive sensory neurons from hPSCs. Lines harboring an inducible NEUROG2 construct were patterned toward precursors with small molecules followed by NEUROG2 overexpression. Neurons expressed key markers, including BRN3A and ISL1, with single-cell RNA sequencing, revealing populations of nociceptors expressing SCN9A and TRP channels. Physiological profiling with multi-electrode arrays revealed that neurons responded to noxious stimuli, including capsaicin. Finally, we modeled pain-like states to identify genes and pathways involved in pain transduction. This study presents an optimized method to efficiently produce nociceptive sensory neurons and provides a tool to aid development of chronic pain research.

Non-coding RNA and n6-methyladenosine modification play crucial roles in neuropathic pain

After peripheral nerve injury, pain signals are transmitted from primary sensory neurons in the dorsal root ganglion (DRG) to the central nervous system. Epigenetic modification affects neuropathic pain through alterations in the gene expression in pain-related areas and glial cell activation. Recent studies have shown that non-coding RNA and n6-methyladenosine (m6A) methylation modification play pivotal regulatory roles in the occurrence and maintenance of neuropathic pain. Dysregulation of the RNA m6A level via dynamic changes in methyltransferase and demethylase after central or peripheral nerve injury commonly regulates pain-associated genes, contributing to the induction and maintenance of neuropathic pain. The dynamic process has significant implications for the development and maintenance of neuropathic pain. However, the underlying mechanisms by which non-coding RNA and m6A RNA modification regulate neuropathic pain are not well-characterized. This article elucidates the multiple mechanisms of non-coding RNA and m6A methylation in the context of neuropathic pain, and summarizes its potential functions as well as recent advances.

Circ_0006404 enhances hepatocellular carcinoma progression by regulating miR-624

Growing studies have demonstrated that circRNAs (circular RNAs) act potential roles in tumor metastasis and progression. However, the expression and function of circ_0006404 in hepatocellular carcinoma (HCC) remain to be investigated. The expression of circ_0006404 and miR-624 was detected by qRT-PCR. CCK-8 assay, flow cytometry, and wound healing were performed to determine cell proliferation, cycle, and migration. The target of circ_0006404 was studied by bioinformatics and luciferase activity analysis. Our data indicated that circ_0006404 was overexpressed in HCC specimens and cells and ectopic expression of circ_0006404 increased HCC cell growth, cycle, and migration. Moreover, we showed that miR-624 was downregulated in HCC specimens and cells and miR-624 expression was negatively correlated with circ_0006404 expression in HCC specimens. Circ_0006404 sponged miR-624 in HCC cell, and the overexpression of circ_0006404 suppressed miR-624 expression in HCC cell. Furthermore, circ_0006404 induced HCC cell growth, cycle, and migration via regulating miR-624. These results elucidated that circ_0006404 facilitated HCC progression and might act as one new biomarker for this carcinoma.

DSCAM-AS1 promotes cervical carcinoma cell proliferation and invasion via sponging miR-338-3p

Deregulated lncRNA DSCAM-AS1 expression was found in several tumors. However, mechanism and functional role of DSCAM-AS1 in cervical carcinoma remain unknown. DSCAM-AS1 was detected in cervical carcinoma specimens and cells by RT-qPCR. CCK-8, Matrigel transwell, and flow cytometry were conducted to determine cell functions. In this research, we firstly we explored DSCAM-AS1 expression in cervical carcinoma cells and specimens. We revealed that DSCAM-AS1 was upregulated in cervical carcinoma lines (C4-1, Caski, Hela, and Siha) compared to GH329 cells. DSCAM-AS1 was upregulated in cervical carcinoma specimens compared to control no-tumor specimens. Overexpression of DSCAM-AS1 induced cervical carcinoma cell growth and cycle. Moreover, our data revealed that miR-338-3p expression was downregulated in cervical carcinoma cells and specimens. There was a negative correlation between miR-338-3p expression and DSCAM-AS1 expression in cervical carcinoma specimens. Elevated expression of miR-338-3p decreased cervical carcinoma cell growth and cycle and invasion. Furthermore, luciferase reporter analysis revealed that miR-338-3p overexpression suppressed luciferase activity of WT-DSCAM-AS1 vector but not the mut-DSCAM-AS1. Ectopic expression of DSCAM-AS1 decreased miR-338-3p expression in the Siha cell. Overexpression of DSCAM-AS1 promoted cervical carcinoma cell growth and cycle via regulating miR-338-3p. These results suggested that DSCAM-AS1 functions as one oncogene through sponging miR-338-3p in cervical carcinoma.

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

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

LncRNA-UC.25 + shRNA Alleviates P2Y14 Receptor-Mediated Diabetic Neuropathic Pain via STAT1

Diabetic neuropathic pain (DNP) is a common complication of diabetes, and its complicated pathogenesis, as well as clinical manifestations, has brought great trouble to clinical treatment. The spinal cord is an important part of regulating the occurrence and development of DNP. Spinal microglia can regulate the activity of spinal cord neurons and have a regulatory effect on chronic pain. P2Y₁₂ receptor is involved in DNP. P2Y₁₄ and P2Y₁₂ receptors belong to the Gi subtype of P2Y receptors, but there is no report that the P2Y₁₄ receptor is involved in DNP. Closely related to many human diseases, the dysregulation of long noncoding RNA (lncRNA) has the effect of promoting or inhibiting the occurrence and development of diseases. The aim of this research is to investigate the function of the spinal cord P2Y₁₄ receptor in type 2 DNP and to understand the function as well as the possible mechanism of lncRNA-UC.25 + (UC.25 +) in rat spinal cord P2Y₁₄ receptor-mediated DNP. Our results showed that P2Y₁₄ shRNA can reduce the expression of P2Y₁₄ in DNP rats, thereby restraining the activation of microglia, decreasing the expression of inflammatory factors and the level of p38 mitogen-activated protein kinase (p38 MAPK) phosphorylation. At the same time, UC.25 + shRNA can downregulate the expression of the P2Y₁₄ receptor, reduce the release of inflammatory factors, and diminish the p38 MAPK phosphorylation, indicating that UC.25 + can alleviate spinal cord P2Y₁₄ receptor-mediated DNP. The RNA immunoprecipitation result showed that UC.25 + enriched signal transducers and activators of transcription1 (STAT1) and positively regulated its expression. The chromatin immunoprecipitation result indicated that STAT1 combined with the promoter region of the P2Y₁₄ receptor and positively regulated the expression of the P2Y₁₄ receptor. Therefore, we infer that UC.25 + may alleviate DNP in rats by regulating the expression of the P2Y₁₄ receptor in spinal microglia via STAT1.

lncRNA DLEU1 Modulates Proliferation, Inflammation, and Extracellular Matrix Degradation of Chondrocytes through Regulating miR-671-5p

Long noncoding RNAs (lncRNAs) have been shown to be involved in the development of osteoarthritis. However, the expression, function, and mechanism of DLEU1 in OA development remain largely unclear. The present reference demonstrates that DLEU1 is overexpressed in OA specimens compared to control cartilages. Inflammatory cytokines IL-1β, TNF-α, and IL-6 induce DLEU1 expression in chondrocytes. Ectopic expression of DLEU1 induces chondrocyte proliferation, degradation of ECM, and inflammation mediators such as IL-6, IL-8, and TNF-α secretion. Moreover, we demonstrated that DLEU1 targets miR-671-5p expression in chondrocytes. Overexpression of DLEU1 suppresses miR-671-5p expression in chondrocytes. The expression of miR-671-5p is decreased in OA specimens compared to control cartilages. There is a negative correlation between the expression of miR-671-5p and DLEU1 in OA specimens. Inflammatory mediators IL-1β, TNF-α, and IL-6 suppress miR-671-5p expression in OA specimens. Elevated expression of miR-671-5p suppresses chondrocyte proliferation, degradation of ECM, and secretion of inflammation mediators. DLEU1 overexpression promotes chondrocytes proliferation, degradation of ECM, and secretion of inflammation mediators via regulating miR-671-5p. These results suggested that DLEU1 acts as one destructive role in OA development via regulating miR-671-5p.

CTBP1-AS2 promoted non-small cell lung cancer progression via sponging the miR-623/MMP3 axis

Mounting evidence indicates that lncRNAs (long noncoding RNAs) are involved in the initiation and development of tumors, including non-small cell lung cancer (NSCLC). However, the involvement of C-terminal binding protein-antisense RNA 2 (CTBP1-AS2) in NSCLC remains to be studied. RT-qPCR was carried out to detect CTBP1-AS2 and miR-623 expression in NSCLC cells and tissues. CCK-8 and flow cytometry were performed to measure cell proliferation and cell cycle progression. Luciferase reporter analysis was performed to study the potential target of CTBP1-AS2. We found that CTBP1-AS2 expression was upregulated in NSCLC cells (SPC-A1, A549, H23, and H1299) compared to 16HBE cells. We demonstrated that the CTBP1-AS2 level was higher in NSCLC specimens than in paired non-tumor specimens. Elevated expression of CTBP1-AS2 increased cell growth and induced cell cycle progression and epithelial-mesenchymal transition (EMT). We also found that ectopic expression of CTBP1-AS2 inhibited miR-623 expression. MMP3 was a direct target of miR-623, and luciferase reporter assays suggested that miR-623 overexpression suppressed the luciferase expression driven by the MMP3 wild-type reporter but not the mutant reporter. Overexpression of miR-623 suppressed MMP3 expression in A549 cells, and overexpression of CTBP1-AS2 increased MMP3 expression in A549 cells. Moreover, the miR-623 level was lower in NSCLC specimens than in paired non-tumor specimens, and CTBP1-AS2 expression was negatively correlated with miR-623 expression in NSCLC samples. Furthermore, overexpression of CTBP1-AS2 enhanced cell growth, cell cycle progression, and EMT progression by modulating MMP3 expression.

Long Noncoding RNA TFAP2A-AS1 Suppressed Hepatitis B Virus Replication by Modulating miR-933/HDAC11

Objective

Studies have shown that long noncoding RNAs (lncRNAs) play crucial roles in multiple tumor types and regulate various biological processes. The present study tried to study lncRNA TFAP2A-AS1 in HBV infection hepatocellular carcinoma.

Methods

The level of TFAP2A-AS1 and miR-933 in HCC cell and samples were detected by qRT-PCR assay. Luciferase reporter gene assay was carried out to study the mechanism of TFAP2A-AS1 and miR-933. Cell proliferation was measured by CCK-8 assay. HBV DNA replication was detected by RT-qPCR.

Results

We firstly demonstrated that TFAP2A-AS1 was downregulated in HCC cell lines and HBV-infected HCC samples compared with nontumor tissues. However, miR-933 was upregulated in HCC cell lines and HBV-infected HCC samples compared with nontumor tissues, and miR-933 was negatively associated with the expression of TFAP2A-AS1 in HBV-correlated HCC samples. TFAP2A-AS1 and HDAC11 expression was decreased and miR-933 was upregulated in the HBV-infected cell HepG2.2.15. TFAP2A-AS1 acted as a sponge for miR-933 and HDAC11 was one direct target gene for miR-933. Overexpression of TFAP2A-AS1 suppressed cell growth, HBV DNA replication, HbeAg, and HbsAg expression, while knockdown of TFAP2A-AS1 enhanced cell proliferation, HBV DNA replication, HbeAg, and HbsAg expression in HepG2.2.15 cell. In addition, ectopic expression of miR-933 promoted cell growth, HBV DNA replication, HbeAg, and HbsAg expression in HepG2.2.15 cell. TFAP2A-AS1 suppressed HBV replication and infection through regulating HDAC11.

Conclusion

These data demonstrated that TFAP2A-AS1 acted crucial roles in the modulation of HbeAg and HbsAg expression and HBV replication and may be one potential target for HBV infection treatment.

LncRNA FER1L4 promotes differentiation and inhibits proliferation of NSCs via miR-874-3p/Ascl2

Neural stem cells (NSCs) may offer beneficeial and promising adjuncts for treatment of neurological diseases such as Alzheimer's disease (AD), Parkinson's disease (PD) and spinal cord injuries. Previous studies showed that LncRNA FER1L4 plays crucial roles in many biological procedures such as invasion, metabolism, apoptosis, and stem cell differentiation. However, the role of FER1L4 in differentiation and growth of NSCs remains unknown. In the present research, we noted that FER1L4 is upregulated in NSCs induced with TNFα. Ectopic expression of FER1L4 suppresses NSCs proliferation and induces NSCs differentiated into neurons and astrocytes. Using Starbase online software, we identified that FER1L4 is one potential target gene of miR-874-3p. Ectopic expression of FER1L4 decreases miR-874-3p expression in NSCs. We identified Ascl2 is one target gene for miR-874-3p. Overexpression of FER1L4 enhances Ascl2 expression in NSCs. Furthermore, we proved that FER1L4 modulates the proliferation and differentiation of NSCs via regulating Ascl2.

lncRNA DARS-AS1 Promoted Osteosarcoma Progression through Regulating miR-532-3p/CCR7

Background

lncRNAs have been indicated to involve in cell invasion, proliferation, and metastasis. However, function of DARS-AS1 in osteosarcoma remains poorly explored.

Methods

DARS-AS1 and miR-532-3p level were measured using qRT-PCR. CCK-8 assay and cell invasion assay were done to study cell functions. Luciferase reporter assay was performed to study the mechanism about DARS-AS1 and miR-532-3p.

Results

We firstly showed that DARS-AS1 expression is upregulated in 73.5% (25/34) of cases with osteosarcoma. Moreover, DARS-AS1 expression is overexpressed in osteosarcoma specimens than in nontumor samples. The DARS-AS1 is overexpressed in the osteosarcoma cell lines (Saos-2, SOSP-9607, U2OS, and MG-63) compared to hFOB. Overexpression of DARS-AS1 promotes cell growth and invasion in MG-63 osteosarcoma cell. DARS-AS1 plays as one sponge for miR-532-3p in osteosarcoma cell, and miR-532-3p overexpression inhibits luciferase activity of DARS-AS1-WT, not DARS-AS1-MUT in MG-63 cell. Ectopic expression of DARS-AS1 inhibits miR-532-3p expression in MG-63 cell. Furthermore, miR-532-3p expression is downregulated in osteosarcoma specimens compared to in paired nontumor samples. MiR-532-3p expression is downregulated in osteosarcoma cell lines compared to hFOB. MiR-532-3p expression is negatively associated with DARS-AS1 expression in osteosarcoma specimens. miR-532-3p directly regulates CCR7 expression in osteosarcoma cell. Elevated DARS-AS1 expression enhances cell growth and invasion via regulating CCR7.

Conclusions

These data firstly suggested that DARS-AS1 exerted as one oncogene in osteosarcoma partly via regulating miR-532-3p/CCR7.

Long Non-coding RNA and mRNA Expression Change in Spinal Dorsal Horn After Exercise in Neuropathic Pain Rats

Exercise can help inhibition of neuropathic pain (NP), but the related mechanism remains being explored. In this research, we performed the effect of swimming exercise on the chronic constriction injury (CCI) rats. Compared with CCI group, the mechanical withdrawal threshold of rats in the CCI-Swim group significantly increased on the 21st and 28th day after CCI surgery. Second-generation RNA-sequencing technology was employed to investigate the transcriptomes of spinal dorsal horns in the Sham, CCI, and CCI-Swim groups. On the 28th day post-operation, 306 intersecting long non-coding RNAs (lncRNAs) and 173 intersecting mRNAs were observed between the CCI vs Sham group and CCI-Swim vs CCI groups. Then, the biological functions of lncRNAs and mRNAs in the spinal dorsal horn of CCI rats were then analyzed. Taking the results together, this study could provide a novel perspective for the treatment for NP.

Neuropeptide Y in the amygdala contributes to neuropathic pain-like behaviors in rats via the neuropeptide Y receptor type 2/mitogen-activated protein kinase axis

Neuropeptide Y (NPY) is a highly conserved endogenous peptide in the central and peripheral nervous systems, which has been implicated in nociceptive signaling in neuropathic pain. However, downstream mechanistic actions remain uncharacterized. In this study, we sought to investigate the mechanism of NPY and its receptor NPY2R in the amygdala in rats with neuropathic pain-like behaviors induced by chronic constriction injury (CCI) of the sciatic nerve. The expression of NPY and NPY2R was found to be aberrantly up-regulated in neuropathic pain-related microarray dataset. Further, NPY was found to act on NPY2R in the basolateral amygdala (BLA). As reflected by the decrease in mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) as well as the increase of NPY expression in the amygdala of rats with neuropathic pain-like behaviors, NPY was closely related to the effect of amygdala nerve activity in neuropathic pain. Subsequently, mechanistic investigations indicated that NPY2R activated the MAPK signaling pathway in the amygdala. NPY2R-induced decrease of MWT and TWL were also restored in the presence of MAPK signaling pathway antagonist. Moreover, it was revealed that NPY2R overexpression promoted the viability while inhibiting the apoptosis of microglia. Taken together, NPY in the amygdala interacts with NPY2R to activate the MAPK signaling pathway, thereby promoting the occurrence of neuropathic pain.

Ion channel long non-coding RNAs in neuropathic pain

Neuropathic pain is one of the primary forms of chronic pain and is the consequence of the somatosensory system's direct injury or disease. It is a relevant public health problem that affects about 10% of the world's general population. In neuropathic pain, alteration in neurotransmission occurs at various levels, including the dorsal root ganglia, the spinal cord, and the brain, resulting from the malfunction of diverse molecules such as receptors, ion channels, and elements of specific intracellular signaling pathways. In this context, there have been exciting advances in elucidating neuropathic pain's cellular and molecular mechanisms in the last decade, including the possible role that long non-coding RNAs (lncRNAs) may play, which open up new alternatives for the development of diagnostic and therapeutic strategies for this condition. This review focuses on recent studies associated with the possible relevance of lncRNAs in the development and maintenance of neuropathic pain through their actions on the functional expression of ion channels. Recognizing the changes in the function and spatio-temporal patterns of expression of these membrane proteins is crucial to understanding the control of neuronal excitability in chronic pain syndromes.

Identification and coregulation pattern analysis of long noncoding RNAs following subacute spinal cord injury

Long noncoding RNAs (lncRNAs) have been demonstrated to play critical regulatory roles in posttranscriptional and transcriptional regulation in eukaryotic cells. However, the characteristics of many lncRNAs, particularly their expression patterns in the lesion epicenter of spinal tissues following subacute spinal cord injury (SCI), remain unclear. In this study, we determined the expression profiles of lncRNAs in the lesion epicenter of spinal tissues after traumatic SCI and predicted latent regulatory networks. Standard Allen's drop surgery was conducted on mice, and hematoxylin and eosin staining was used to observe the damaged area. High-throughput sequencing was performed to identify the differential expression profiles of lncRNAs. Quantitative real-time polymerase chain reaction was conducted to evaluate the quality of the sequencing results. Bioinformatics analyses, including Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis, coexpression analysis, and protein-protein interaction analysis, were performed. Targeted binding of lncRNA-miRNA-mRNA was predicted by TargetScan and miRanda. A total of 230 differentially expressed lncRNAs were identified and preliminarily verified, and some potential regulatory networks were constructed. These findings improve our understanding of the mechanisms underlying subacute SCI; differentially expressed lncRNAs are closely involved in pathophysiological processes by regulating multiple pathways. Further studies are essential for revealing the exact mechanism underlying competing endogenous RNA pathways in vivo and in vitro.

Differential Expression of Long Non-Coding RNAs and Their Role in Rodent Neuropathic Pain Models

Neuropathic pain, which is accompanied by an unpleasant sensation, affects the patient’s quality of life severely. Considering the complexity of the neuropathic pain, there are huge unmet medical needs for it while current effective therapeutics remain far from satisfactory. Accordingly, exploration of mechanisms of neuropathic pain could provide new therapeutic insights. While numerous researches have pointed out the contribution of sensory neuron-immune cell interactions, other mechanisms of action, such as long non-coding RNAs (lncRNAs), also could contribute to the neuropathic pain observed in vivo. LncRNAs have more than 200 nucleotides and were originally considered as transcriptional byproducts. However, recent studies have suggested that lncRNAs played a significant role in gene regulation and disease pathogenesis. A substantial number of long non-coding RNAs were expressed differentially in neuropathic pain models. Besides, therapies targeting specific lncRNAs can significantly ameliorate the development of neuropathic pain, which reveals the contribution of lncRNAs in the generation and maintenance of neuropathic pain and provides a new therapeutic strategy. The primary purpose of this review is to introduce recent studies of lncRNAs on different neuropathic pain models.

DNA Methylation and Non-Coding RNAs during Tissue-Injury Associated Pain

While about half of the population experience persistent pain associated with tissue damages during their lifetime, current symptom-based approaches often fail to reduce such pain to a satisfactory level. To provide better patient care, mechanism-based analgesic approaches must be developed, which necessitates a comprehensive understanding of the nociceptive mechanism leading to tissue injury-associated persistent pain. Epigenetic events leading the altered transcription in the nervous system are pivotal in the maintenance of pain in tissue injury. However, the mechanisms through which those events contribute to the persistence of pain are not fully understood. This review provides a summary and critical evaluation of two epigenetic mechanisms, DNA methylation and non-coding RNA expression, on transcriptional modulation in nociceptive pathways during the development of tissue injury-associated pain. We assess the pre-clinical data and their translational implication and evaluate the potential of controlling DNA methylation and non-coding RNA expression as novel analgesic approaches and/or biomarkers of persistent pain.

Advances With Non-coding RNAs in Neuropathic Pain

Neuropathic pain (NP) is one of the most common types of clinical pain. The common causes of this syndrome include injury to the central or peripheral nervous systems and pathological changes. NP is characterized by spontaneous pain, hyperalgesia, abnormal pain, and paresthesia. Because of its diverse etiology, the pathogenesis of NP has not been fully elucidated and has become one of the most challenging problems in clinical medicine. This kind of pain is extremely resistant to conventional treatment and is accompanied by serious complications. Non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), contribute to diverse biological processes by regulating the expression of various mRNAs involved in pain-related pathways, at the posttranscriptional level. Abnormal regulation of ncRNAs is closely related to the occurrence and development of NP. In this review, we summarize the current state of understanding of the roles of different ncRNAs in the development of NP. Understanding these mechanisms can help develop novel therapeutic strategies to prevent or treat chronic pain.

Long Non-coding RNAs Gabarapl2 and Chrnb2 Positively Regulate Inflammatory Signaling in a Mouse Model of Dry Eye

Purpose: To elucidate the expression profile and the potential role of long non-coding ribonucleic acids (RNAs) (lncRNAs) in a dry eye disease (DED) model.

Methods: A DED model was established in C57BL/6J mice with 0.2% benzalkonium chloride (BAC) twice a day for 14 days. The differentially expressed lncRNAs were detected by RNA-seq technology (Gene Expression Omnibus, GEO GSE186450) and the aberrantly expressed lncRNAs were further verified by RT-qPCR. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted to predicate the related candidate genes and potential pathological pathways. Cells from a human corneal epithelial cell line (HCECs) were cultured under hyperosmolarity. The regulation of inflammatory factors by silencing potential targeted lncRNAs was verified in vitro in HCECs.

Results: In our study, a significant increase in corneal fluorescence staining and a reduction in tear production were observed in DED mice at all follow-ups compared with the controls, and the differences were increasing over time. In total, 2,649 upregulated and 704 downregulated lncRNAs were identified in DED mice. We selected six aberrantly expressed and most abundant lncRNAs and performed RT-qPCR using the samples for RNA-seq. Chrnb2, Gabarapl2, and Usp31 were thereby confirmed as the most significantly altered lncRNAs. Pathway analysis revealed that the neuroactive ligand–receptor interaction signaling pathway was the most enriched, followed by the calcium signaling pathway and cytokine–cytokine receptor interaction. Following treatment of Gabarapl2 siRNA and Chrnb2 siRNA, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 were significantly downregulated in the HCECs.

Conclusion: Our study suggests that Chrnb2 and Gabarapl2 may be involved in the inflammation response by regulating TNF-α, IL-1β, and IL-6 in DED. These candidate lncRNAs may be both potential biomarkers and therapeutic targets for DED.

MeCP2 Epigenetic Silencing of Oprm1 Gene in Primary Sensory Neurons Under Neuropathic Pain Conditions

Opioids are the last option for the pharmacological treatment of neuropathic pain, but their antinociceptive effects are limited. Decreased mu opioid receptor (MOR) expression in the peripheral nervous system may contribute to this. Here, we showed that nerve injury induced hypermethylation of the Oprm1 gene promoter and an increased expression of methyl-CpG binding protein 2 (MeCP2) in injured dorsal root ganglion (DRG). The downregulation of MOR in the DRG is closely related to the augmentation of MeCP2, an epigenetic repressor, which could recruit HDAC1 and bind to the methylated regions of the Oprm1 gene promoter. MeCP2 knockdown restored the expression of MOR in injured DRG and enhanced the analgesic effect of morphine, while the mimicking of this increase via the intrathecal infusion of viral vector-mediated MeCP2 was sufficient to reduce MOR in the DRG. Moreover, HDAC1 inhibition with suberoylanilide hydroxamic acid, an HDAC inhibitor, also prevented MOR reduction in the DRG of neuropathic pain mice, contributing to the augmentation of morphine analgesia effects. Mechanistically, upregulated MeCP2 promotes the binding of a high level of HDCA1 to hypermethylated regions of the Oprm1 gene promoter, reduces the acetylation of histone H3 (acH3) levels of the Oprm1 gene promoter, and attenuates Oprm1 transcription in injured DRG. Thus, upregulated MeCP2 and HDAC1 in Oprm1 gene promoter sites, negatively regulates MOR expression in injured DRG, mitigating the analgesic effect of the opioids. Targeting MeCP2/HDAC1 may thus provide a new solution for improving the therapeutic effect of opioids in a clinical setting.

The role of circular RNAs in neuropathic pain

Neuropathic pain (NP) results from a lesion or disease of the nervous system and accompanied by chronic pain, leading a serious public health issue and economic burden. In terms of the NP mechanisms remaining poorly understood, circular RNAs (circRNAs), owing to their high stability and evolutionary conservation, are expected to be used as potential therapeutic targets or diagnostic biomarkers. In this review, we concisely discuss the characteristics and biological functions of circRNAs. As emerging evidence we reviewed, deregulation of circRNAs (e.g., circ-Filip1l, circHIPK3, ciRS-7, circRNA.2837, circ-Ankib1 and circAnks1a) were involved in NP development. It suggested that specific circRNAs modulated through sponging their target miRNAs and thus regulated the homologous downstream mRNAs and proteins in neuropathic pain. These findings provide a theoretical basis for circRNAs use as biomarkers and therapeutic targets in neuropathic pain.

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

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LncRNA PTTG3P induced aberrant glycosylated IgA1 production and B cell growth in IgA nephropathy

Growing evidences suggested that lncRNAs played functional role in several cell functions such as cell growth, invasion, migration, metabolize, apoptosis, and differentiation. However, roles of lncRNA in the development and progression of IgAN remain unknown. In this reference, we indicated that PTTG3P level was overexpressed in IgAN samples compared to healthy subject. PTTG3P expression was also higher in urinary of IgAN cases than in urinary of healthy control. Furthermore, the urinary expression of PTTG3P was correlated with PTTG3P expression in intra-renal of IgAN cases. PTTG3P overexpression induced B cell growth and enhanced cyclin D1 and ki-67 expression. Overexpression of PTTG3P induced IL-1β and IL-8 production. miR-383 level was decreased in IgAN samples compared to healthy subject. In addition, miR-383 expression was also lower in urinary of IgAN cases than in urinary of healthy control. Elevated miR-383 expression decreased luciferase intensity regulated with PTTG3P, while overexpression of miR-383 had no effect on luciferase intensity of the mutant PTTG3P. PTTG3P overexpression suppressed miR-383 expression in B cells. Ectopic miR-383 expression suppressed B cell growth and IL-1β and IL-8 production. Finally, we showed that overexpression of PTTG3P promoted B cell growth and IL-1β and IL-8 production via regulating miR-383. There results proved that PTTG3P played crucial role in progression of IgAN.

Transcriptomic Analysis of Long Noncoding RNA and mRNA Expression Profiles in the Amygdala of Rats with Bone Cancer Pain-Depression Comorbidity

Bone cancer pain (BCP)–depression comorbidity has become a complex clinical problem during cancer treatment; however, its underlying molecular mechanisms have not been clarified. Several long noncoding RNAs (lncRNAs) have been demonstrated to be promising therapeutic targets in depression, but research on the role of lncRNAs in BCP–depression comorbidity has been limited. Therefore, high-throughput RNA sequencing was performed to detect differentially expressed profiles in the amygdala of a BCP–depression rat model in this study. We detected 330 differentially expressed mRNAs (DEmRNAs) and 78 differentially expressed lncRNAs (DElncRNAs) in the BCP–depression comorbidity model and then verified the expression of six DEmRNAs and six DElncRNAs with the greatest degrees of difference by RT-qPCR. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that differentially expressed genes were strongly enriched in inflammatory and immunologic systemic responses. Then the nuclear factor kappa B (NF-κB) signaling pathway and the Th17 differentiation pathway showed significant differences, as determined by Western blot analysis. Finally, we constructed a protein–protein interaction (PPI) network to explore the potential regulatory mechanism of DEmRNAs. In conclusion, our study reveals a new resource for the understanding of dysregulated lncRNAs and mRNAs in BCP–depression comorbidity and provides novel potential therapeutic targets for further approaches.

LINC01783 accelerated tongue squamous cell carcinoma progression via inhibiting miR-199b-5p

Growing studies illustrated that lncRNAs exert critical roles in development and occurrence of tumours including TSCC. In this research, we indicated that LINC01783 was up‐regulated in TSCC cells (SCC1, Cal27, UM1 and SCC4) when compared to NHOK cell. RT‐qPCR analysis indicated that LINC01783 was overexpressed in 22 TSCC cases (73.3%, 22/30) compared with no‐tumour specimens. LINC01783 level was up‐regulated in TSCC specimens when compared to no‐tumour specimens. Ectopic expression of LINC01783 promoted TSCC cell cycle and growth and EMT progression in both TSCC cell SCC1 and Cal27. Overexpression of LINC01783 sponged miR‐199b‐5p in TSCC cell and elevated expression of LINC01783 inhibited miR‐199b‐5p expression. Moreover, we illustrated that miR‐199b‐5p was down‐regulated in TSCC cells and specimen and LINC01783 level was up‐regulated in TSCC specimens when compared to no‐tumour specimens. Elevated expression of LINC01783 promoted TSCC cell growth, cycle and EMT progression by sponging miR‐199b‐5p. These data suggested that LINC01783 functioned as one oncogene and might be one treatment target for TSCC.

Knockdown of XIST Attenuates Cerebral Ischemia/Reperfusion Injury Through Regulation of miR-362/ROCK2 Axis

Long non-coding RNAs (lncRNAs) are considered as critical regulators in the pathogenesis of cerebral ischemia. In this present study, we aimed to investigate the impact and underlying mechanism of lncRNA X-inactive specific transcript (XIST) in cerebral ischemia/reperfusion (I/R) injury. An oxygen-glucose deprivation/reperfusion (OGD/R) model in PC12 cells was applied to mimic cerebral I/R injury in vitro and middle cerebral artery occlusion/reperfusion (MCAO/R) model was performed in mice to mimic cerebral I/R injury in vivo. Real-time PCR, fluorescence in situ hybridization (FISH) assay, and western blotting assay were carried out to detect the expression levels of XIST, miR-362, and Rho-related coiled-coil containing protein kinase 2 (ROCK2). The functional experiments were measured by CCK-8 assay, immumofluorescence assay, ELISA assay, TUNEL, and TTC staining. Results displayed that XIST was elevated in PC12 cells with OGD/R, as well as in the ischemic penumbra of mice with MCAO/R. In vitro, knockdown of XIST facilitated cell survival, inhibited apoptosis, and alleviated inflammation injury in OGDR PC12 cells. In vivo, inhibition of XIST remarkably reduced the neurological impairments, promoted neuron proliferation, and suppressed apoptosis in MCAO mice. Mechanistically, XIST acted as a competing endogenous RNA of miR-362 to regulate the downstream gene ROCK2. In conclusion, depletion of XIST attenuated I/R-induced neurological impairment and inflammatory response via the miR-362/ROCK2 axis. These findings offer a potential novel strategy for ischemic stroke therapy.

HOXC13-AS Induced Extracellular Matrix Loss via Targeting miR-497-5p/ADAMTS5 in Intervertebral Disc

Background/Aims: LncRNAs are a new modulator in the development of intervertebral disc degeneration. However, the functional role and mechanism of HOXC13-AS in intervertebral disc degeneration remain unclear. Methods: qRT-PCR analysis was performed to measure the relative expression levels of HOXC13-AS and miR-497-5p, and the levels of IL-1β, IL-6, and TNF-α in the medium supernatant were analyzed by ELISA. The related mechanism between HOXC13-AS and miR-497-5p was detected by luciferase assays. Results: The results revealed that TNF-α and IL-1β induced HOXC13-AS expression in NP cells. HOXC13-AS was overexpressed in IDD specimens compared to control specimens, and higher expression of HOXC13-AS was correlated with high Pfirrmann scores. Ectopic expression of HOXC13-AS promoted MMP-3 and ADAMTS4 and inhibited aggrecan and collagen II expression in NP cells. Furthermore, overexpression of HOXC13-AS increased the expression of inflammatory cytokines, including IL-1β, IL-6, and TNF-α. Our results demonstrated that TNF-α and IL-1β induced ADAMTS5 expression and suppressed miR-497-5p expression. miR-497-5p was downregulated in IDD specimens compared to control specimens, and the lower expression of miR-497-5p was correlated with high Pfirrmann scores. The miR-497-5p level was negatively proportional to HOXC13-AS expression in IDD specimens. Luciferase analysis data indicated that ADAMTS5 was a direct target gene of miR-497-5p. HOXC13-AS induced inflammatory cytokine expression and ECM degradation by modulating miR-497-5p/ADAMTS5. Conclusion: HOXC13-AS may be a treatment target for IDD.

LncRNA RNCR3 promotes endothelial cell proliferation and inflammatory cytokine secretion via regulating miR-185-5p/cyclin D2 axis

Endothelial cell is one critical structure of blood vessels, and irregular migration and proliferation of endothelial cell might cause progression of several vascular diseases such as atherosclerosis and restenosis. We showed that TNF-α, PDGF-bb, and IL-1β promote RNCR3 expression in a dose-dependent manner inhuman endothelial cell. RNCR3 level is higher in serum of atherosclerosis patients compared with those in control volunteers. Overexpression of RNCR3 promotes cell proliferation and three inflammatory cytokine secretion including IL-6, IL-1β, and TNF-α in endothelial cell. We illustrated that overexpression of RNCR3 inhibits miR-185-5p expression in endothelial cell. Furthermore, we indicated that miR-185-5p level is lower in the serum of patients with atherosclerosis compared with those in control volunteers. There is a negative correlation between miR-185-5p and RNCR3 expression in serum of patients with atherosclerosis. Using Targetscan, it predicted that miR-185-5p may bind to cyclin D2 and miR-185-5p is one potential target of miR-185-5p. Luciferase reporter data indicated that miR-185-5p suppresses luciferase value of wild-type cyclin D2 while it has no influence of cyclin D2 mutant. Overexpression of RNCR3 enhances cyclin D2 expression in endothelial cell. Moreover, RNCR3 induces cell growth and enhances inflammatory cytokine secretion through modulating cyclin D2 expression in endothelial cell. These results suggested that RNCR3 may serve as one new target for the treatment of atherosclerosis.

Genetic and Epigenomic Modifiers of Diabetic Neuropathy

Diabetic neuropathy (DN), the most common chronic and progressive complication of diabetes mellitus (DM), strongly affects patients’ quality of life. DN could be present as peripheral, autonomous or, clinically also relevant, uremic neuropathy. The etiopathogenesis of DN is multifactorial, and genetic components play a role both in its occurrence and clinical course. A number of gene polymorphisms in candidate genes have been assessed as susceptibility factors for DN, and most of them are linked to mechanisms such as reactive oxygen species production, neurovascular impairments and modified protein glycosylation, as well as immunomodulation and inflammation. Different epigenomic mechanisms such as DNA methylation, histone modifications and non-coding RNA action have been studied in DN, which also underline the importance of “metabolic memory” in DN appearance and progression. In this review, we summarize most of the relevant data in the field of genetics and epigenomics of DN, hoping they will become significant for diagnosis, therapy and prevention of DN.

LINC00514 promotes gastric cancer cell growth and EMT progression via miR-204-3p/KRAS

Long noncoding RNAs (LncRNAs) participate in tumor development and tumorigenesis. However, the mechanism, function and expression of LINC00514 in GC remain unknown. We showed that LINC00514 was upregulated in GC specimens compared with nontumor specimens. Overexpression of LINC00514 induced cell growth and EMT progression in GC cells. By using bioinformatics prediction, we found that miR-204-3p contained binding sequences for LINC00514. Luciferase reporter analysis noted that miR-204-3p overexpression decreased the luciferase expression under LINC00514-wild-type and KRAS-wild-type reporters but not that under mutant reporter. Ectopic LINC00514 expression decreased miR-204-3p expression. miR-204-3p expression was decreased in GC specimens compared with nontumor specimens and that LINC00514 was negatively correlated with miR-204-3p in GC specimens. Furthermore, KRAS was identified as a target gene for miR-204-3p according to TargetScan. Elevated miR-204-3p expression inhibited KRAS expression in HGC-27 cells, and ectopic expression of LINC00514 enhanced KRAS expression. Elevated LINC00514 expression enhanced cell growth and EMT progression by sponging KRAS. Our data indicated that LINC00514 may act as an oncogene and therapeutic target for GC.

MSC-AS1 induced cell growth and inflammatory mediators secretion through sponging miR-142-5p/DDX5 in gastric carcinoma

Emerging studies have noted that dysregulated lncRNAs are implicated in cancer progression and tumorigenesis. We first showed that MSC-AS1 was overexpressed in gastric cancer (GC) cells (HGC-27, MKN-45, SGC-7901 and MGC-803 cells) compared with GES cells. We observed that MSC-AS1 was upregulated in GC specimens compared with paired normal specimens. MSC-AS1 increased cell growth and cycle progression. Moreover, the overexpression of MSC-AS1 enhanced the secretion of the inflammatory mediators IL-1β, IL-6 and TNF-α. We found that the overexpression of MSC-AS1 inhibited the expression of miR-142-5p in HGC-27 cells. We noted that DDK5 was a target gene of miR-142-5p. The overexpression of miR-142-5p suppressed the luciferase activity of wild-type DDX5, but the luciferase activity of the mutant DDX5 was not changed. We showed that miR-142-5p was downregulated in GC specimens compared with paired normal specimens. MSC-AS1 expression was inversely correlated with miR-142-5p expression in GC specimens. MSC-AS1 induced cell growth, cell cycle progression and inflammatory mediator secretion by modulating DDX5. These results showed that MSC-AS1 functions as a key oncogene in the development of GC.

Identification of potential biomarkers of long non-coding RNAs in neuropathic pain using bioinformatic analysis: A protocol for systematic review and meta-analysis

BACKGROUND

Long non-coding RNAs (LncRNAs) play important roles in the regulation of neuropathic pain (NP) development. LncRNAs dysregulations are related to the development of NP. However, a comprehensive meta-analysis has never been conducted to assess the relationship between LncRNAs and NP. To combine the results of dysregulated LncRNAs in individual NP studies and to identify potential LncRNAs biomarkers.

METHODS

LncRNAs profiling studies of NP were extracted from Pubmed, Web of science, Embase, Google Scholar, and Chinese National Knowledge Infrastructure, and the Chinese Biomedical Literature Database if they met the inclusion criteria. The meta-analysis was conducted using a random effects model to identify the effect of each multiple-reported LncRNAs. We also performed subgroup analysis according to LncRNAs detecting methods and sample type. Sensitivity analysis was performed on the sample size. Bioinformatic analysis was performed to identify the potential biomatic functions. All results were represented as log10 odds ratios.

RESULTS

This review will be disseminated in print by peer-review.

CONCLUSION

The identified LncRNAs may be closely linked with NP and may act as potentially useful biomarkers.

ETHICS AND DISSEMINATION

The private information from individuals will not publish. This systematic review also will not involve endangering participant rights. Ethical approval is not available. The results may be published in a peer- reviewed journal or disseminated in relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/ZRX7C.

LINC00472 regulates vascular smooth muscle cell migration and proliferation via regulating miR-149-3p

LncRNAs are one group of gene modulators functioning via several mechanisms in pathological and physiological conditions. We noted that LINC00472 expression level is elevated in atherosclerotic coronary tissues compared with normal coronary artery samples. LINC00472 is also upregulated in vascular smooth muscle cells (VSMCs) induced by TNF-α and PDGF-BB. Ectopic expression of LINC00472 induced VSMC migration and proliferation. The predicted binding sequence between miR-149-3p and LINC00472 was analyzed by LncBase Predicted. Overexpression of miR-149-3p decreases the luciferase activity of wild-type reporter plasmid, but not the mutant one. Ectopic expression of LINC00472 suppresses the expression of miR-149-3p in VSMCs. Furthermore, we demonstrated that miR-149-3p expression is decreased in atherosclerotic coronary tissues. MiR-149-3p was downregulated in VSMCs induced by TNF-α and PDGF-BB. Overexpression of LINC00472 induces VSMC migration and proliferation via regulating miR-149-3p. These data suggested that LINC00472 acts a critical role in the migration and proliferation of VSMCs partly via modulating miR-149-3p.

Transcriptome profiling of long noncoding RNAs and mRNAs in spinal cord of a rat model of paclitaxel-induced peripheral neuropathy identifies potential mechanisms mediating neuroinflammation and pain

Background

Paclitaxel is a widely prescribed chemotherapy drug for treating solid tumors. However, paclitaxel-induced peripheral neuropathy (PIPN) is a common adverse effect during paclitaxel treatment, which results in sensory abnormalities and neuropathic pain among patients. Unfortunately, the mechanisms underlying PIPN still remain poorly understood. Long noncoding RNAs (lncRNAs) are novel and promising targets for chronic pain treatment, but their involvement in PIPN still remains unexplored.

Methods

We established a rat PIPN model by repetitive paclitaxel application. Immunostaining, RNA sequencing (RNA-Seq) and bioinformatics analysis were performed to study glia cell activation and explore lncRNA/mRNA expression profiles in spinal cord dorsal horn (SCDH) of PIPN model rats. qPCR and protein assay were used for further validation.

Results

PIPN model rats developed long-lasting mechanical and thermal pain hypersensitivities in hind paws, accompanied with astrocyte and microglia activation in SCDH. RNA-Seq identified a total of 814 differentially expressed mRNAs (DEmRNA) (including 467 upregulated and 347 downregulated) and 412 DElncRNAs (including 145 upregulated and 267 downregulated) in SCDH of PIPN model rats vs. control rats. Functional analysis of DEmRNAs and DElncRNAs identified that the most significantly enriched pathways include immune/inflammatory responses and neurotrophin signaling pathways, which are all important mechanisms mediating neuroinflammation, central sensitization, and chronic pain. We further compared our dataset with other published datasets of neuropathic pain and identified a core set of immune response-related genes extensively involved in PIPN and other neuropathic pain conditions. Lastly, a competing RNA network analysis of DElncRNAs and DEmRNAs was performed to identify potential regulatory networks of lncRNAs on mRNA through miRNA sponging.

Conclusions

Our study provided the transcriptome profiling of DElncRNAs and DEmRNAs and uncovered immune and inflammatory responses were predominant biological events in SCDH of the rat PIPN model. Thus, our study may help to identify promising genes or signaling pathways for PIPN therapeutics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02098-y.

Long Noncoding RNA ANPODRT Overexpression Protects Nucleus Pulposus Cells from Oxidative Stress and Apoptosis by Activating Keap1-Nrf2 Signaling

Oxidative stress and subsequent nucleus pulposus (NP) cell apoptosis are important contributors to the development of intervertebral disc degeneration (IDD). Emerging evidences show that long noncoding RNAs (lncRNAs) play a role in the pathogenesis of IDD. In this study, we investigated the role of lncRNA ANPODRT (anti-NP cell oxidative damage-related transcript) in oxidative stress and apoptosis in human NP cells. We found that ANPODRT was downregulated in degenerative NP tissues and in NP cells treated with tert-butyl hydroperoxide (TBHP, the oxidative stress inducer). ANPODRT overexpression alleviated oxidative stress and apoptosis in NP cells exposed to TBHP, while ANPODRT knockdown exerted opposing effects. Mechanistically, ANPODRT facilitated nuclear factor E2-related factor 2 (Nrf2) accumulation and nuclear translocation and activated its target genes by disrupting the kelch-like ECH-associated protein 1- (Keap1-) Nrf2 association in NP cells. Nrf2 knockdown abolished the antioxidative stress and antiapoptotic effects of ANPODRT in NP cells treated with TBHP. Collectively, our findings suggest that ANPODRT protects NP cells from oxidative stress and apoptosis, at least partially, by activating Nrf2 signaling, implying that ANPODRT may be a potential therapeutic target for IDD.

Guanosine-5'-triphosphate cyclohydrolase 1 regulated long noncoding RNAs are potential targets for microglial activation in neuropathic pain

Several studies have confirmed that microglia are involved in neuropathic pain. Inhibition of guanosine-5'-triphosphate cyclohydrolase 1 (GTPCH1) can reduce the inflammation of microglia. However, the precise mechanism by which GTPCH1 regulates neuropathic pain remains unclear. In this study, BV2 microglia were transfected with adenovirus to knockdown GTPCH1 expression. High throughput sequencing analysis revealed that the mitogen-activated protein kinase (MAPK) related pathways and proteins were the most significantly down-regulated molecular function. Co-expression network analysis of Mapk14 mRNA and five long noncoding RNAs (lncRNAs) revealed their correlation. Quantitative reverse transcription-polymerase chain reaction revealed that among five lncRNAs, ENSMUST00000205634, ENSMUST00000218450 and ENSMUST00000156079 were related to the downregulation of Mapk14 mRNA expression. These provide some new potential targets for the involvement of GTPCH1 in neuropathic pain. This study is the first to note the differential expression of lncRNAs and mRNA in GTPCH1 knockdown BV2 microglia. Findings from this study reveal the mechanism by which GTPCH1 activates microglia and provide new potential targets for microglial activation in neuropathic pain.

LINC01410 accelerated the invasion and proliferation of osteosarcoma by sponging miR-3128

Increasing evidence has shown that lncRNAs are closely correlated with cell apoptosis, autophagy and progression. However, the role of LINC01410 in osteosarcoma has not been verified. We determined that LINC01410 was overexpressed in osteosarcoma specimens and cell lines. The expression of LINC01410 was upregulated in 22 osteosarcoma patients (22/30, 73%) compared to control normal samples. Ectopic expression of LINC01410 promoted the osteosarcoma cell cycle, proliferation and invasion. Overexpression of LINC01410 induced N-cadherin and Vimentin expression and inhibited E-cadherin expression in osteosarcoma cells. LINC01410 acted as a sponge for miR-3128. The results showed that miR-3128 overexpression decreased the luciferase activity of WT-LINC01410 but not mut-LINC01410 in MG-63 cells. Upregulation of LINC01410 expression suppressed miR-3128 expression in MG-63 cells. Moreover, LINC01410 overexpression increased osteosarcoma cell invasion and growth by modulating miR-3128. These data indicated that LINC01410 acted as an oncogene in osteosarcomagenesis and might be a potential new strategy for osteosarcoma treatment.

LncRNA ROR1-AS1 accelerates osteosarcoma invasion and proliferation through modulating miR-504

Long non-coding RNAs (LncRNAs) play vital roles in the progression and development of tumors. However, the functional role of ROR1-AS1 in osteosarcoma has not been investigated. We found that ROR1-AS1 was upregulated in osteosarcoma tissues compared to non-tumor samples. Elevated expression of ROR1-AS1 promoted cyclin D1, PCNA and ki-67 expression and increased cell cycle and growth in MG-63 cell. Moreover, overexpression of ROR1-AS1 induced cell migration in MG-63 cell, promoting N-cadherin and vimentin expression and inhibiting E-cadherin expression. Dual-luciferase assay proved that ROR1-AS1 served as one sponge for miR-504 and ROR1-AS1 overexpression suppressed miR-504 expression in MG-63 cell. ROR1-AS1 expression was lower in osteosarcoma tissues compared to non-tumor samples. Pearson's correlation assay showed a negative correlation between miR-504 and ROR1-AS1 expression. MiR-504 overexpression partly abrogated ROR1-AS1-induced effects on osteosarcoma cell migration and proliferation. These data implied that ROR1-AS1 played as an oncogene and might be a new treatment target for osteosarcoma.

LncRNA KCNA2-AS regulates spinal astrocyte activation through STAT3 to affect postherpetic neuralgia

Objectives

Postherpetic neuralgia (PHN) is the most common complication of herpes zoster, but the mechanism of PHN is still unclear. Activation of spinal astrocytes is involved in PHN. Our study aims to explore whether lncRNA KCNA2 antisense RNA (KCNA2-AS) regulates spinal astrocytes in PHN through signal transducers and activators of transcription 3 (STAT3).

Methods

Varicella zoster virus (VZV)-infected CV-1 cells were injected into rats to construct a PHN model. Primary spinal cord astrocytes were activated using S-Nitrosoglutathione (GSNO). Glial fibrillary acidic protein (GFAP; marker of astrocyte activation), phosphorylated STAT3 (pSTAT3), and KCNA2-AS were analyzed by immunofluorescence and RNA fluorescence in situ hybridization. RNA pull-down and RNA immunoprecipitation were used to detect binding of KCNA2-AS to pSTAT3.

Results

KCNA2-AS was highly expressed in the spinal cord tissue of PHN model rats, and was positively correlated with GFAP expression. GFAP was significantly increased in GSNO-induced cells, but the knockdown of KCNA2-AS reversed this result. Meanwhile, pSTAT3 was significantly increased in GSNO-induced cells, but knockdown of KCNA2-AS reduced pSTAT3 within the nucleus while the total pSTAT3 did not change significantly. pSTAT3 bound to KCNA2-AS and this binding increased with GSNO treatment. Furthermore, knockdown of KCNA2-AS in PHN model rats relieved mechanical allodynia.

Conclusion

Down-regulation of KCNA2-AS alleviates PHN partly by reducing the translocation of pSTAT3 cytoplasm to the nucleus and then inhibiting the activation of spinal astrocytes.