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

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.

Bioinformatics analysis of effective biomarkers and immune infiltration in type 2 diabetes with cognitive impairment and aging

With the increasing prevalence of diabetes mellitus worldwide, type 2 diabetes mellitus (T2D) combined with cognitive impairment and aging has become one of the common and important complications of diabetes mellitus, which seriously affects the quality of life of the patients, and imposes a heavy burden on the patients' families and the society. Currently, there are no special measures for the treatment of cognitive impairment and aging in type 2 diabetes mellitus. Therefore, the search for potential biological markers of type 2 diabetes mellitus combined with cognitive impairment and aging is of great significance for future precisive treatment. We downloaded three gene expression datasets from the GEO database: GSE161355 (related to T2D with cognitive impairment and aging), GSE122063, and GSE5281 (related to Alzheimer's disease). Differentially expressed genes (DEGs) were identified, followed by gene set enrichment analysis (GSEA). A protein-protein interaction (PPI) network was constructed using the STRING database, and the top 15 hub genes were identified using the CytoHubba plugin in Cytoscape. Core genes were ultimately determined using three machine learning methods: LASSO regression, Support Vector Machine Recursive Feature Elimination (SVM-RFE), and Linear Discriminant Analysis (LDA). The diagnostic performance of these genes was assessed using ROC curve analysis and validated in an independent dataset (GSE5281). Regulatory genes related to ferroptosis were screened from the FerrDb database, and their biological functions were further explored through GO and KEGG enrichment analyses. Finally, the CIBERSORT algorithm was used to analyze immune cell infiltration, and the correlation between core genes and immune cell infiltration levels was calculated, leading to the construction of an mRNA-miRNA regulatory network. In the GSE161355 and GSE122063 datasets, 217 common DEGs were identified. GSEA analysis revealed their enrichment in the PI3K-PLC-TRK signaling pathway, TP53 regulation of metabolic genes pathway, Notch signaling pathway, among others. PPI network analysis identified 15 candidate core genes, and further selection using LASSO, LDA, and SVM-RFE machine learning algorithms resulted in 6 core genes: BCL6, TP53, HSP90AA1, CRYAB, IL1B, and DNAJB1. ROC curve analysis indicated that these genes had good diagnostic performance in the GSE161355 dataset, with TP53 and IL1B achieving an AUC of 0.9, indicating the highest predictive accuracy. BCL6, HSP90AA1, CRYAB, and DNAJB1 also had AUCs greater than 0.8, demonstrating moderate predictive accuracy. Validation in the independent dataset GSE5281 showed that these core genes also had good diagnostic performance in Alzheimer's disease samples (AUC > 0.6). Ferroptosis-related analysis revealed that IL1B and TP53 play significant roles in apoptosis and immune response. Immune cell infiltration analysis showed that IL1B is significantly positively correlated with infiltration levels of monocytes and NK cells, while TP53 is significantly negatively correlated with infiltration levels of follicular helper T cells. The construction of the miRNA-mRNA regulatory network suggested that miR-150a-5p might play a key role in the regulation of T2D-associated cognitive impairment and aging by TP53. This study, by integrating bioinformatics and machine learning methods, identified BCL6, TP53, HSP90AA1, CRYAB, IL1B, and DNAJB1 as potential diagnostic biomarkers for T2D with cognitive impairment and aging, with a particular emphasis on the significance of TP53 and IL1B in immune cell infiltration. These findings not only enhance our understanding of the molecular mechanisms linking type 2 diabetes to cognitive impairment and aging, providing new targets for early diagnosis and treatment, but also offer new directions and targets for basic research.

NLR family pyrin domain containing 3 (NLRP3) inflammasomes and peripheral neuropathic pain - Emphasis on microRNAs (miRNAs) as important regulators

Neuropathic pain is caused by the lesion or disease of the somatosensory system and can be initiated and/or maintained by both central and peripheral mechanisms. Nerve injury leads to neuronal damage and apoptosis associated with the release of an array of pathogen- or damage-associated molecular patterns to activate inflammasomes. The activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome contributes to neuropathic pain and may represent a novel target for pain therapeutic development. In the current review, we provide an up-to-date summary of the recent findings on the involvement of NLRP3 inflammasome in modulating neuropathic pain development and maintenance, focusing on peripheral neuropathic conditions. Here we provide a detailed review of the mechanisms whereby NLRP3 inflammasomes contribute to neuropathic pain via (1) neuroinflammation, (2) apoptosis, (3) pyroptosis, (4) proinflammatory cytokine release, (5) mitochondrial dysfunction, and (6) oxidative stress. We then present the current research literature reporting on the antinociceptive effects of several natural products and pharmacological interventions that target activation, expression, and/or regulation of NLRP3 inflammasome. Furthermore, we emphasize the effects of microRNAs as another regulator of NLRP3 inflammasome. In conclusion, we summarize the possible caveats and future perspectives that might provide successful therapeutic approaches against NLRP3 inflammasome for treating or preventing neuropathic pain conditions.

Intradermal miR-16-5p targets Akt3 and reduces RTX-induced postherpetic neuralgia-mimic pain in mice

The molecular mechanisms of refractory pain in postherpetic neuralgia (PHN) patients are not fully understood. PHN may be related to skin abnormality after herpes zoster induced skin lesions. We previously reported 317 differentially expressed microRNAs (miRNAs) in PHN skin compared with the contralateral normal mirror skin. In this study, 19 differential miRNAs were selected and the expression was validated in other 12 PHN patients. The expression levels of miR-16-5p, miR-20a-5p, miR-505-5p, miR-3664-3p, miR-4714-3p and let-7a-5p are lower in PHN skin, which is the same as those in microarray experiment. To evaluate the effects of cutaneous miRNA on PHN, the expression of candidate miRNAs is further observed in resiniferatoxin (RTX) induced PHN-mimic mice model. In the plantar skin of RTX mice, miR-16-5p and let-7a-5p are downregulated, with the same expression trend of PHN patients. In addition, intraplantar injection of agomir-16-5p reduced mechanical hyperalgesia, and improved thermal hypoalgesia in RTX mice. Furthermore, agomir-16-5p down-regulated the expression levels of Akt3, which is the target gene of agomir-16-5p. These results suggest that intraplantar miR-16-5p may alleviate RTX induced PHN-mimic pain by inhibiting the expression of Akt3 in the skin.

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.

Regulatory mechanisms of tetramethylpyrazine on central nervous system diseases: A review

Central nervous system (CNS) diseases can lead to motor, sensory, speech, cognitive dysfunction, and sometimes even death. These diseases are recognized to cause a substantial socio-economic impact on a global scale. Tetramethylpyrazine (TMP) is one of the main active ingredients extracted from the Chinese herbal medicine Ligusticum striatum DC. (Chuan Xiong). Many in vivo and in vitro studies have demonstrated that TMP has a certain role in the treatment of CNS diseases through inhibiting calcium ion overload and glutamate excitotoxicity, anti-oxidative/nitrification stress, mitigating inflammatory response, anti-apoptosis, protecting the integrity of the blood-brain barrier (BBB) and facilitating synaptic plasticity. In this review, we summarize the roles and mechanisms of action of TMP on ischemic cerebrovascular disease, spinal cord injury, Parkinson’s disease, Alzheimer’s disease, cognitive impairments, migraine, and depression. Our review will provide new insights into the clinical applications of TMP and the development of novel therapeutics.

METTL3 suppresses neuropathic pain via modulating N6-methyladenosine-dependent primary miR-150 processing

Methyltransferase-like 3 (METTL3)-modulated N6-methyladenosine (m6A) was recently identified as an important epigenetic regulation type during RNA processing and contributes to multiple pathological processes. Neuropathic pain (NP) is induced by a lesion of the somatosensory nervous system, and the detailed pathways by which METTL3/m6A regulated to modulate gene dysregulation and enable NP have remained unclear. Therefore, this study investigated the function of METTL3-mediated m6A methylation on miRNA maturation, and investigated how this regulation contributes to NP progression. A rat model characterized with typical NP was established by a spared nerve-injury (SNI) method. By analyzing the expression levels of METTL3 and m6A methylation, we found that METTL3, along with m6A methylation, was dramatically downregulated in NP rats in contrast to the sham ones. Functionally, enhanced METTL3 promoted the m6A methylation in total RNAs and inhibited NP progression, whereas silencing METTL3 suppressed m6A methylation and increased NP severity. Mechanistically, METTL3 accelerated miR-150 maturation via mediating m6A methylation of primiR-150 at locus 498, cooperating with the “m6A reader” YTHDF2. Meanwhile, miR-150 could directly target brain-derived neurotrophic factor (BDNF) mRNA, and the METTL3/miR-150/BDNF regulatory pathway was finally established. Clinically, we proved that serum METTL3 mRNA was also downregulated in Shingles patients with NP, suggesting its diagnostic potential. In conclusion, we demonstrated an essential function of METTL3-regulated N6-methyladenosine during NP progression via modulating primiR-150 maturation. Serum METTL3 could effectively differentiate NP patients from healthy people, and is useful for dynamic monitoring of diseases after treatment. Therefore, the METTL3/miR-150/BDNF pathway may be a promising therapeutic target for NP patients.

The Roles of Tetramethylpyrazine During Neurodegenerative Disease

With the aging of the world population, neurodegenerative diseases are considered crippling diseases, which seriously affect the quality of life and are an increasing burden on society and the economy. As a major alkaloid in Ligusticum chuanxiong Hort, tetramethylpyrazine (TMP) plays an increasingly significant role during neurodegenerative diseases, including roles as an anti-inflammatory, antioxidative, antiplatelet citatory poisoning, and anti-inflammation. This review focuses on the latest advances in the roles and mechanisms of action of TMP in neurodegenerative diseases to stimulate new concepts and methods for the prevention and treatment of neurodegenerative diseases.

Long noncoding RNA FTX ameliorates hydrogen peroxide-induced cardiomyocyte injury by regulating the miR-150/KLF13 axis

Background

Myocardial reperfusion is an effective therapy for acute myocardial infarction (AMI). However, ischemia/reperfusion (I/R) injury following myocardial reperfusion is a significant limitation for AMI treatment. Five prime to Xist (FTX) was recognized as a biomarker of multiple diseases, including heart disease. However, the molecular mechanism of FTX in I/R injury is unclear.

Methods

Cell viability was evaluated by using cell counting kit-8 (CCK-8) assay. Apoptosis was analyzed by using a caspase-3 activity detection kit and flow cytometry. The expression of FTX, microRNA (miR)-150, and Kruppel-like factor 13 (KLF13) was measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The interaction of miR-150 and FTX or KLF13 was confirmed by a dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Protein expression of KLF13 was examined by Western blot. The role of FTX was detected in I/R-injured heart tissues in vivo.

Results

Hydrogen peroxide (H₂O₂) induced cardiomyocyte injury by decreasing cell viability and expediting cell apoptosis. However, FTX alleviated cardiomyocyte injury by promoting cell proliferation and restricting cell apoptosis of H9C2 cells that were treated with H₂O₂. In addition, we discovered that FTX directly interacted with miR-150, while KLF13 was a target of miR-150. Rescue experiments showed that miR-150 neutralized the FTX-mediated promotion of cell progression and restriction of cell apoptosis in H9C2 cells treated with H₂O₂. KLF13 knockdown restored the effect of miR-150 on increased proliferation and decrease in apoptosis in H₂O₂-treated cardiomyocytes. Furthermore, FTX enhanced the expression of KLF13 protein through interaction with miR-150. Upregulation of FTX repressed apoptosis in I/R-injured heart tissues in vivo.

Conclusion

FTX relieves H₂O₂-induced cardiomyocyte injury by increasing KLF13 expression via depletion of miR-150, thus providing a novel therapeutic target for the alleviation of I/R injury.

Diagnostic and therapeutic biomarkers for Alzheimer's disease in human-derived platelets

BACKGROUND

Diagnosis of current Alzheimer's disease (AD) is difficult even for medical specialists, and there is no clear biomarker. Also, aging is highly related to the onset of AD.

OBJECTIVES

The purpose of this study is to screen miRNA as an aging-considered biomarker for AD treatment and diagnosis.

METHODS

The patient group for this study was divided into a young normal, old normal, or AD group. We developed a method of discovering sequentially expressed miRNAs to distinguish miRNAs that were sequentially expressed in the three groups.

RESULTS

Sequentially expressed miRNAs correlated highly with the patient's age, and most showed expression patterns that distinguished young, old, and AD. Specifically, the miRNA expression we found showed similar patterns in the brains of patients with AD. Among the selected miRNAs, one set derived from the same precursor: The expression of miR-150 was a disease- and age-specific downregulation in both 3p and 5p forms, and the precursor also had the same pattern. We named that triple matching. Also, the found miR-150 precursor had AD-specific miRNA-imbalance characteristics.

CONCLUSIONS

We developed a novel AD diagnostic method using triple matching and miRNA-imbalance. The triple matching and miRNA imbalance-based relative ratio diagnosis method we developed will be very powerful in resolving the challenges of absolute diagnostic quantification based on biomarker expression. Also, our research results suggest the possibility of a treatment target for AD.

Tetramethylpyrazine ameliorates isoflurane-induced cognitive dysfunction by inhibiting neuroinflammation via miR-150 in rats

Tetramethylpyrazine (TMP) has neuroprotective effects in the pathogenesis of some human diseases, such as Parkinson's disease. The present study aimed to investigate the role of TMP in isoflurane-induced cognitive dysfunction in rats, and further identify the mechanisms involved in the protective effects of TMP. The Morris water maze test was used to evaluate the cognitive function of rats exposed to isoflurane or treated with TMP. ELISA was conducted to evaluate the effects of isoflurane or TMP on neuroinflammation. The expression of microRNA-150 (miR-150) was measured using reverse transcription-quantitative PCR, and the potential target genes of miR-150 were predicted and verified. The impaired cognitive function induced by isoflurane in the rats was significantly ameliorated by treatment with TMP. In addition, TMP treatment in rats attenuated neuroinflammation caused by isoflurane. The expression of miR-150 was inhibited by isoflurane exposure, but was enhanced by TMP treatment in rats. Furthermore, the overexpression of miR-150 alleviated the isoflurane-induced cognitive dysfunction and neuroinflammation, while the neuroprotective effects of TMP were significantly abrogated by the knockdown of miR-150. AKT3 was a direct target of miR-150, and its mRNA expression was significantly decreased by the overexpression of miR-150 in isoflurane- and TMP-treated rats. These results demonstrated the protective effects of TMP against isoflurane-induced cognitive dysfunction, which were achieved by attenuating neuroinflammation via the regulation of the miR-150/AKT3 pathway. In addition, miR-150 may serve as a novel therapeutic target for the alleviation of cognitive dysfunction induced by anesthetics.

Role of Spinal Cord Akt-mTOR Signaling Pathways in Postoperative Hyperalgesia Induced by Plantar Incision in Mice

Poor postoperative pain (POP) control increases perioperative morbidity, prolongs hospitalization days, and causes chronic pain. However, the specific mechanism(s) underlying POP is unclear and the identification of optimal perioperative treatment remains elusive. Akt and mammalian target of rapamycin (mTOR) are expressed in the spinal cord, dorsal root ganglion, and sensory axons. In this study, we explored the role of Akt and mTOR in pain-related behaviors induced by plantar incision in mice. Plantar incision activated spinal Akt and mTOR in a dose-dependent manner. Pre-treatment with Akt inhibitors intrathecally prevented the activation of mTOR dose-dependently. In addition, blocking the Akt-mTOR signaling cascade attenuated pain-related behaviors and spinal Fos protein expression induced by plantar incision. Our observations demonstrate that Akt-mTOR might be a potential therapeutic target for the treatment of POP.

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.

TRPV1, Targeted by miR-338-3p, Induces Neuropathic Pain by Interacting with NECAB2

A variety of studies have proposed that transient receptor potential vanilloid 1 (TRPV1) is involved in the progression of multiple diseases, including neuropathic pain. Although increased expression of TRPV1 in chronic constriction injury was described earlier, the underlying regulatory mechanisms of TRPV1 in neuropathic pain remain largely unknown. In our study, we constructed a chronic constriction injury (CCI) rat model to deeply analyze the mechanisms underlying TRPV1. RT-qPCR-indicated TRPV1 mRNA and protein expression were extremely upregulated in CCI rat dorsal spinal cord tissues. Then, TRPV1 was corroborated to interact with N-terminal EF-hand Ca²⁺-binding protein 2 (NECAB2). The mRNA and protein levels of NECAB2 were increased in CCI tissues. Moreover, TRPV1 and NECAB2 together regulated nociceptive procession-associated protein metabotropic glutamate receptor 5 (mGluR5), phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2), and Ca²⁺ in isolated microglia of CCI rats. Moreover, TRPV1 upregulation apparently increased mechanical allodynia and thermal hyperalgesia as well as the expression of inflammation-associated genes (COX-2, TNF-α, and IL-6). In addition, downregulation of NECAB2 significantly decreased mechanical allodynia and thermal hyperalgesia as well as the expression of COX-2, TNF-α, and IL-6. Furthermore, TRPV1 was confirmed to be a downstream target of miR-338-3p. TRPV1 overexpression abolished the inhibitory effect by miR-338-3p elevation on neuropathic pain development. In summary, this study proved TRPV1, targeted by miR-338-3p, induced neuropathic pain by interacting with NECAB2, which provides a potential therapeutic target for neuropathic pain treatment.