MiR-28-5p relieves neuropathic pain by targeting Zeb1 in CCI rat models

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.

Diagnostic and Predictive Value of LncRNA MCM3AP-AS1 in Sepsis and Its Regulatory Role in Sepsis-Induced Myocardial Dysfunction

The present study focused on exploring the clinical value and molecular mechanism of LncRNA MCM3AP antisense RNA 1 (MCM3AP-AS1) in sepsis and sepsis-induced myocardial dysfunction (SIMD). 122 sepsis patients and 90 healthy were included. Sepsis patients were categorized into SIMD and non-MD. The expression levels of MCM3AP-AS1 and miRNA were examined using RT-qPCR. Diagnostic value of MCM3AP-AS1 in sepsis assessed by ROC curves. Logistic regression to explore risk factors influencing the occurrence of SIMD. Cardiomyocytes were induced by LPS to construct cell models in vitro. CCK-8, flow cytometry, and ELISA to analyze cell viability, apoptosis, and inflammation levels. Serum MCM3AP-AS1 was upregulated in patients with sepsis. The sensitivity and specificity of MCM3AP-AS1 were 75.41% and 93.33%, for recognizing sepsis from healthy controls. Additionally, elevated MCM3AP-AS1 is a risk factor for SIMD and can predict SIMD development. Compared with the LPS-induced cardiomyocytes, inhibition of MCM3AP-AS1 significantly attenuated LPS-induced apoptosis and inflammation; however, this attenuation was partially reversed by lowered miR-28-5p, but this reversal was partially eliminated by CASP2. MCM3AP-AS1 may be a novel diagnostic biomarker for sepsis and can predict the development of SIMD. MCM3AP-AS1 probably participated in SIMD progression by regulating cardiomyocyte inflammation and apoptosis through the target miR-28-5p/CASP2 axis.

Transplantation of MiR-28-5p-Modified BMSCs Promotes Functional Recovery After Spinal Cord Injury

Traumatic spinal cord injury (TSCI) is a prevalent central nervous system condition that imposes a significant burden on both families and society, affecting more than 2 million people worldwide. Recently, there has been increasing interest in bone marrow mesenchymal stem cell (BMSC) transplantation as a promising treatment for spinal cord injury (SCI) due to their accessibility and low immunogenicity. However, the mere transplantation of BMSCs has limited capacity to directly participate in the repair of host spinal cord nerve function. MiR-28-5p, identified as a key differentially expressed miRNA in spinal cord ischemia-reperfusion injury, exhibits differential expression and regulation in various neurological diseases. Nevertheless, its involvement in this process and its specific regulatory mechanisms in SCI remain unclear. Therefore, this study aimed to investigate the potential mechanisms through which miR-28-5p promotes the neuronal differentiation of BMSCs both in vivo and in vitro. Our results indicate that miR-28-5p may directly target Notch1, thereby facilitating the neuronal differentiation of BMSCs in vitro. Furthermore, the transplantation of lentivirus-mediated miR-28-5p-overexpressed BMSCs into SCI rats effectively improved footprint tests and Basso, Beattie, and Bresnahan (BBB) scores, ameliorated histological morphology (hematoxylin-eosin [HE] and Nissl staining), promoted axonal regeneration (MAP2 and growth-associated protein 43 [GAP43]), and facilitated axonal remyelination (myelin basic protein [MBP]). These findings may suggest that miR-28-5p-modified BMSCs could serve as a therapeutic target to enhance the behavioral and neurological recovery of SCI rats.

Newly discovered functions of miRNAs in neuropathic pain: Transitioning from recent discoveries to innovative underlying mechanisms

Neuropathic pain is a widespread clinical issue caused by somatosensory nervous system damage, affecting numerous individuals. It poses considerable economic and public health challenges, and managing it can be challenging due to unclear underlying mechanisms. Nevertheless, emerging evidence suggests that neurogenic inflammation and neuroinflammation play a role in developing pain patterns. Emerging evidence suggests that neurogenic inflammation and neuroinflammation play significant roles in developing neuropathic pain within the nervous system. Increased/decreased miRNA expression patterns could affect the progression of neuropathic and inflammatory pain by controlling nerve regeneration, neuroinflammation, and the expression of abnormal ion channels. However, our limited knowledge of miRNA targets hinders a complete grasp of miRNA's functions. Meanwhile, exploring exosomal miRNA, a recently uncovered role, has significantly advanced our comprehension of neuropathic pain's pathophysiology in recent times. In this review, we present a comprehensive overview of the latest miRNA studies and explore the possible ways miRNAs might play a role in the development of neuropathic pain.

The Role of miRNAs in Neuropathic Pain

Neuropathic pain is a debilitating condition affecting around 8% of the adult population in the UK. The pathophysiology is complex and involves a wide range of processes, including alteration of neuronal excitability and synaptic transmission, dysregulated intracellular signalling and activation of pro-inflammatory immune and glial cells. In the past 15 years, multiple miRNAs–small non-coding RNA–have emerged as regulators of neuropathic pain development. They act by binding to target mRNAs and preventing the translation into proteins. Due to their short sequence (around 22 nucleotides in length), they can have hundreds of targets and regulate several pathways. Several studies on animal models have highlighted numerous miRNAs that play a role in neuropathic pain development at various stages of the nociceptive pathways, including neuronal excitability, synaptic transmission, intracellular signalling and communication with non-neuronal cells. Studies on animal models do not always translate in the clinic; fewer studies on miRNAs have been performed involving human subjects with neuropathic pain, with differing results depending on the specific aetiology underlying neuropathic pain. Further studies using human tissue and liquid samples (serum, plasma, saliva) will help highlight miRNAs that are relevant to neuropathic pain diagnosis or treatment, as biomarkers or potential drug targets.

Advances in the role and mechanism of miRNA in inflammatory pain

Pain is a distressing experience associated with tissue damage or potential tissue damage, and its occurrence is related to sensory, emotional, cognitive and social factors. Inflammatory pain is one of the chronic pains where pain hypersensitivity are functional features of inflammation used to protect tissues from further damage. Pain has a serious impact on people's lives and has become a social problem that cannot be ignored. MiRNAs are small non-coding RNA molecules that exert directing effects on RNA silencing by complementary binding to the 3'UTR of target mRNA. MiRNAs can target a number of protein-coding genes and participate in almost all developmental and pathological processes in animals. Growing studies have suggested that miRNAs have significant implications for inflammatory pain via participating in multiple processes during the occurrence and development, such as affecting the activation of glial cells, regulating pro-inflammatory cytokines and inhibiting central and peripheral sensitization. In this review, the advances in the role of miRNAs in inflammatory pain were discussed. miRNAs as a class of micro-mediators are potential biomarkers and therapeutic targets for inflammatory pain, which provides a better diagnostic and treatment approach for inflammatory pain.

Emerging roles of miRNAs in neuropathic pain: From new findings to novel mechanisms

Neuropathic pain, which results from damage to the somatosensory nervous system, is a global clinical condition that affects many people. Neuropathic pain imposes significant economic and public health burdens and is often difficult to manage because the underlying mechanisms remain unclear. However, mounting evidence indicates a role for neurogenic inflammation and neuroinflammation in pain pattern development. There is increasing evidence that the activation of neurogenic inflammation and neuroinflammation in the nervous system contribute to neuropathic pain. Altered miRNA expression profiles might be involved in the pathogenesis of both inflammatory and neuropathic pain by regulating neuroinflammation, nerve regeneration, and abnormal ion channel expression. However, the lack of knowledge about miRNA target genes prevents a full understanding of the biological functions of miRNAs. At the same time, an extensive study on exosomal miRNA, a newly discovered role, has advanced our understanding of the pathophysiology of neuropathic pain in recent years. This section provides a comprehensive overview of the current understanding of miRNA research and discusses the potential mechanisms of miRNAs in neuropathic pain.

The role of the ZEB1–neuroinflammation axis in CNS disorders

Zinc finger E-box binding homeobox 1 (ZEB1) is a master modulator of the epithelial–mesenchymal transition (EMT), a process whereby epithelial cells undergo a series of molecular changes and express certain characteristics of mesenchymal cells. ZEB1, in association with other EMT transcription factors, promotes neuroinflammation through changes in the production of inflammatory mediators, the morphology and function of immune cells, and multiple signaling pathways that mediate the inflammatory response. The ZEB1–neuroinflammation axis plays a pivotal role in the pathogenesis of different CNS disorders, such as brain tumors, multiple sclerosis, cerebrovascular diseases, and neuropathic pain, by promoting tumor cell proliferation and invasiveness, formation of the hostile inflammatory micromilieu surrounding neuronal tissues, dysfunction of microglia and astrocytes, impairment of angiogenesis, and dysfunction of the blood–brain barrier. Future studies are needed to elucidate whether the ZEB1–neuroinflammation axis could serve as a diagnostic, prognostic, and/or therapeutic target for CNS disorders.

MicroRNA-28-5p as a potential diagnostic biomarker for chronic periodontitis and its role in cell proliferation and inflammatory response

Background/purpose

Recent studies have pointed to the crucial role of microRNAs (miRNAs) in chronic periodontitis (CP). This study investigated the regulation and potential mechanisms of miR-28-5p in CP patients and lipopolysaccharide (LPS)-induced periodontal ligament cells (PDLCs).

Materials and methods

76 CP patients and 71 periodontally healthy subjects were included. RT-qPCR was employed to examine miR-28-5p and sphingosine kinase −1 (SPHK1) in subjects’ gingival sulcus fluid and PDLCs. The diagnostic performance was evaluated by measuring the area under the curve (AUC) of the receiver operating characteristic (ROC) analysis. Pearson correlation coefficient (r) was adopted to explore the statistical relation between indicators. PDLCs proliferation and inflammation factors were determined by CCK-8 and ELISA assay. The direct target gene was validated by a dual-luciferase reporter assay.

Results

miR-28-5p was lowly expressed in CP patients and LPS-induced PDLCs (P < 0.05). AUC for miR-28-5p was 0.937, which had certain diagnostic value. Additionally, miR-28-5p was negatively correlated with periodontal clinical indicators and inflammatory factors. Cell proliferation of PDLCs was inhibited and inflammation was promoted under LPS induction, however, elevated miR-28-5p diminished the effect of LPS (P < 0.05). SPHK1 acts as a miR-28-5p target and the elevation of SPHK1 caused by LPS treatment was inhibited by the increased miR-28-5p.

Conclusion

Present study revealed that miR-28-5p could be served as a potential diagnostic biomarker for CP. And miR-28-5p may participate in CP progression by targeting SPHK1 to regulate the proliferation and inflammation of PDLCs. This study may offer insights into CP treatment and diagnosis.

New Vistas in microRNA Regulatory Interactome in Neuropathic Pain

Neuropathic pain is a chronic pain condition seen in patients with diabetic neuropathy, cancer chemotherapy-induced neuropathy, idiopathic neuropathy as well as other diseases affecting the nervous system. Only a small percentage of people with neuropathic pain benefit from current medications. The complexity of the disease, poor identification/lack of diagnostic and prognostic markers limit current strategies for the management of neuropathic pain. Multiple genes and pathways involved in human diseases can be regulated by microRNA (miRNA) which are small non-coding RNA. Several miRNAs are found to be dysregulated in neuropathic pain. These miRNAs regulate expression of various genes associated with neuroinflammation and pain, thus, regulating neuropathic pain. Some of these key players include adenylate cyclase (Ac9), toll-like receptor 8 (Tlr8), suppressor of cytokine signaling 3 (Socs3), signal transducer and activator of transcription 3 (Stat3) and RAS p21 protein activator 1 (Rasa1). With advancements in high-throughput technology and better computational power available for research in present-day pharmacology, biomarker discovery has entered a very exciting phase. We dissect the architecture of miRNA biological networks encompassing both human and rodent microRNAs involved in the development of neuropathic pain. We delineate various microRNAs, and their targets, that may likely serve as potential biomarkers for diagnosis, prognosis, and therapeutic intervention in neuropathic pain. miRNAs mediate their effects in neuropathic pain by signal transduction through IRAK/TRAF6, TLR4/NF-κB, TXIP/NLRP3 inflammasome, MAP Kinase, TGFβ and TLR5 signaling pathways. Taken together, the elucidation of the landscape of signature miRNA regulatory networks in neuropathic pain will facilitate the discovery of novel miRNA/target biomarkers for more effective management of neuropathic pain.

Overexpression of miR-378 Alleviates Chronic Sciatic Nerve Injury by Targeting EZH2

In numerous studies, microRNAs (miRNAs) have been authenticated to play vital roles in the pathophysiology of neuropathic pain and other neurological diseases. In our study, we focused on evaluating miR-378 and its potential effects in neuropathic pain development, as well as the underlying molecular mechanisms. Primarily, a chronic sciatic nerve injury (CCI) rat model was established. Next, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was employed to measure the expression levels of miR-378 and EZH2 mRNA; the EZH2 protein expression levels were detected by western blot. A luciferase activity assay monitored the interaction of miR-378 and EZH2. Mechanical and thermal hyperalgesia was also performed to quantitate the effects of overexpression of miR-378 or EZH2 on the CCI rats. We found that miR-378 was down-regulated in the CCI rats, and the overexpression of miR-378 produced significant relief in their pain management. EZH2 was the downstream gene of miR-378 and was negatively regulated by miR-378. The up-regulation of EZH2 reduced the inhibitory effects of miR-378 on the development of neuropathic pain in the CCI rats. miR-378 acts as an inhibitor in the progression of neuropathic pain via targeting EZH2; the miR-378/EZH2 axis may be a novel target for the diagnosis and therapy of neuropathic pain in clinical treatment.

ZEB1 Induces Ddr1 Promoter Hypermethylation and Contributes to the Chronic Pain in Spinal Cord in Rats Following Oxaliplatin Treatment

Application of chemotherapeutic oxaliplatin represses gene transcription through induction of DNA methylation, which may contribute to oxaliplatin-induced chronic pain. Here, Ddr1, which showed an increased methylation in the promoter, was screened from the SRA methylation database (PRJNA587622) after oxaliplatin treatment. qPCR and MeDIP assays verified that oxaliplatin treatment increased the methylation in Ddr1 promoter region and decreased the expression of DDR1 in the neurons of spinal dorsal horn. In addition, overexpression of DDR1 by intraspinal injection of AAV-hSyn-Ddr1 significantly alleviated the mechanical allodynia induced by oxaliplatin. Furthermore, we found that oxaliplatin treatment increased the expression of DNMT3b and ZEB1 in dorsal horn neurons, and promoted the interaction between DNMT3b and ZEB1. Intrathecal injection of ZEB1 siRNA inhibited the enhanced recruitment of DNMT3b and the hypermethylation in Ddr1 promoter induced by oxaliplatin. Finally, ZEB1 siRNA rescued the DDR1 downregulation and mechanical allodynia induced by oxaliplatin. In conclusion, these results suggested that the ZEB1 recruited DNMT3b to the Ddr1 promoter, which induced the DDR1 downregulation and contributed to the oxaliplatin-induced chronic pain.

MiR-122-5p suppresses neuropathic pain development by targeting PDK4

The complex pathogenesis and limited efficacy of available treatment make neuropathic pain difficult for long periods of time. Several findings suggested the regulatory role of microRNA in the development of neuropathic pain. This study aims to investigate the functional role of miR-122-5p in the development of neuropathic pain. Down-regulation of miR-122-5p was observed in spinal cords of rats with neuropathic pain. We also found that overexpressing miR-122-5p by intrathecal injection of miR-122-5p lentivirus in a mouse model of chronic sciatic nerve injury (CCI) prevented neuropathic pain behavior. In HEK-293 T cells, luciferase activity was significantly decreased in the transfection group with mimic-miR-122-5p in wild-type PDK4 reporter, compared with mutant PDK4 reporter. Increased PDK4 expression was also observed during the progression of neuropathic pain. Intrathecal injection of both mimic-miR-122-5p and shPDK4 in CCI mice downregulated PDK4 expression to a lower level when compared with injected with shPDK4. In CCI mice, transfection of shPDK4 suppressed mechanical allodynia and thermal hyperalgesia, while co-transfection of shPDK4 and LV-miR-122-5p resulted in stronger levels of mechanical allodynia and thermal hyperalgesia inhibition. Taken together, the data suggest that miR-122-5p inhibits PDK4 expression, attenuating neuropathic pain. This result suggests the potential role of miR-122-5p acting as a target for the treatment of neuropathic pain.

miR‑28‑5p inhibits the migration of breast cancer by regulating WSB2

MicroRNAs (miRNAs or miRs) play an important role in the tumorigenesis and progression of breast cancer. However, the function of miR‑28‑5p in breast cancer migration has yet to be determined. In the present study, Human MicroRNA Expression Database (HMED) analysis revealed that the expression level of miR‑28‑5p was significantly lower in breast cancer tissue than in normal breast tissue. Kaplan-‑Meier plotter (KMPLOT) analysis revealed that the low expression level of miR‑28‑5p was associated with a poor survival in breast cancer. In addition, reverse transcription‑quantitative PCR (RT‑qPCR) revealed that the expression of miR‑28‑5p was significantly lower in breast cancer cell lines compared with that in human mammary epithelial cells (HMECs). Moreover, transfection with miR‑28‑5p mimics suppressed the migration of MCF‑7 cells, whereas an miR‑28‑5p inhibitor exerted the opposite effect. Gene chip assay identified 648 differentially expressed genes (DEGs) in cells overexpressing miR‑28‑5p. The DEGs are enriched in the 'focal adhesion' and 'pathway in cancer' pathways. The expression levels of Ras‑related protein Rap‑1b (RAP1B), WD repeat and SOCS box containing 2 (WSB2) and vascular endothelial growth factor A (VEGFA) were confirmed by RT‑qPCR. Furthermore, transfection with miR‑28‑5p mimics decreased WSB2 expression, whereas the miR‑28‑5p inhibitor increased the expression of WSB2, at both the transcriptional and translational levels. miR‑28‑5p targets the 3'UTR of WSB2, and the binding site is conserved in multiple species, with a consensus motif of 5'‑AGCUCCUU‑3'. Moreover, WSB2 overexpression promoted the migration of MCF‑7 cells which had been inhibited by miR‑28‑5p. UALCAN analysis revealed that WSB2 was significantly upregulated in primary breast tumor tissue, and a high expression level of WSB2 was associated with a poor survival in breast cancer. Furthermore, immunohistochemistry revealed that the expression of WSB2 was markedly higher in breast cancer tissue compared with that in adjacent normal breast tissue. Taken together, the findings of the present study demonstrate that miR‑28‑5p inhibits the migration of breast cancer cells by regulating WSB2 expression, and the miR‑28‑5p/WSB2 axis may be a novel therapeutic target in breast cancer.

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.

MicroRNA-448 modulates the progression of neuropathic pain by targeting sirtuin 1

MicroRNAs (miRNAs) play crucial roles in the pathogenesis of neuropathic pain. The present study investigated the effects of miR-448 on the progression of neuropathic pain in a rat model of chronic constriction injury (CCI) of the sciatic nerve. Reverse-transcription quantitative polymerase chain reaction was conducted to detect the gene expression. The paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) were used to assess the pain threshold. The protein expression levels of interleukin (IL)-6, IL-1β and tumor necrosis factor-α (TNF-α) were detected by ELISA. The target of miR-448 was predicted by TargetScan software. The Student's t-test or one-way ANOVA were used to identify statistical differences among groups. miR-448 was persistently upregulated in CCI rats, and both mechanical allodynia and thermal hyperalgesia in CCI rats were decreased following miR-448 downregulation. The expression levels of IL-1β, IL-6 and TNF-α were significantly increased in CCI rats compared with controls, and these effects were reversed following treatment with a miR-448 inhibitor. A luciferase reporter assay revealed that sirtuin 1 (SIRT1) was a target gene of miR-448. SIRT1 was found to abrogate the effect of miR-448 on neuropathic pain development. Collectively, the results of the present study revealed that miR-448 promoted neuropathic pain in CCI rats by regulating neuroinflammation via SIRT1. Therefore, SIRT1 may be considered as a novel biomarker for neuropathic pain.

miR-129-5p Alleviates Neuropathic Pain Through Regulating HMGB1 Expression in CCI Rat Models

Recently, microRNAs are reported to be participated in the development of pain and persistence of neuropathic and inflammatory pain in animal models. Here, we characterized the functional role of miR-129-5p in pain processing in chronic constriction injury (CCI) rat models. Bilateral CCI operation was used to generate neuropathic pain rat model. Paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) were used to assess pain-related behaviors. Gene expression was evaluated using qRT-PCR, luciferase assay, western blotting, and enzyme-linked immunosorbent assay. Compared with the control rats, expression level of miR-129-5p was downregulated significantly over time in CCI rats post operation. Interestingly, downregulation of miR-129-5p in CCI rats was correlated with increased proinflammatory cytokine expression and pain-related behaviors. Furthermore, we found that miR-129-5p alleviated neuropathic pain through downregulating high mobility group protein B1 (HMGB1) expression in CCI rats as overexpression of miR-129-5p suppressed expression of both HMGB1 and proinflammatory cytokine and alleviated pain sensation in CCI rats. In summary, our results show that alteration in miR-129-5p expression contributes to pain processing in our CCI pain rat model, suggesting miR-129-5p could be a causal factor in neuropathic pain and serve as a promising potential biomarker and therapeutic target for neuropathic pain.

Effects of miR-150 on neuropathic pain process via targeting AKT3

MicroRNAs (miRNA) are reported to be a vital regulator of neuropathic pain. Even so, the molecular mechanisms of miRNA function on neuropathic pain development are known little. Our research was designed to investigate the role of miRNA in neuropathic pain development in rat modle set up by chronic sciatic nerve injury (CCI). Increasing miR-150 expression could significantly alleviate neuropathic pain in CCI rats. For farther researching the regulation mechanism of miR-150 on neuropathic pain, we screened AKT3 as a possible target of miR-150 by bioinformatic mechods and predicted a possible target of miR-150 in 3'-untranslated region (UTR) of AKT3 who serves as an oncogene. In rat model, the expression both of AKT3 mRNA and protein were significantly upregulated. The overexpressed miR-150 importantly repressed the level of AKT3 and simultaneously alleviate mechanical and thermal hyperalgesia in rat model. These suppressant impacts of miR-150 on neuropathic pain process can be reversed by the overexpression of AKT3. Considering all above results, our research declared that miR-150 can restrain neuropathic pain process though targeting AKT3 in vivo, suggesting that miR-150 could be the therapeutic target for neuropathic pain therapy by regulating AKT3.