Neuropathic pain is the main form of chronic pain. Neuropathic pain is mainly caused by damage and disorder of the nervous system. Therefore, it is important to investigate the pathological mechanism of NP and identify effective therapeutic targets.
Recently, several studies have been highlighted the function and clinical significance of non-coding RNA in NP (6, 7). However, RNA crosstalk on NP has yet been resolved. This work combined with lncRNA, miRNA, and mRNA expression profiles and constructed a lncRNA-miRNA-mRNA regulatory network is to provide new ideas for post-transcriptional gene regulation of NP. In addition, with the help of big data mining and public database annotations, we explored the key molecules of multiple physiological and pathological processes of NP and identified several potential NP drug targets by reviewing the previous work.
The identified DEmiR and DEGs have not been reported in the previous study related to the pathogenesis of neuropathic pain. MiR-940 is mainly related to proliferation and metastasis of cancer, such as gastric cancer (11), endometrial carcinoma (12), thyroid cancer (13), and cervical cancer (14). Interestingly, miR-940 also regulates the inflammatory response in osteoarthritis (OA) (15) and spinal cord injury (16). lncRNA XIST enhances ANLN by up-regulating miR-200c-3p, promotes the chemical resistance of breast cancer cells to doxorubicin and provides a potential new therapeutic target for the breast (17). The exosomes rich in miR-2277-30p tend to have a high abundance of β4 and lead to a cancer promoting effect (18). The serum levels of miR-5689 were significantly correlated with overall survival after initiation of eribulin treatment, providing an evidence that serum miRNA can serve as biomarkers for the predicting the development of new distant metastasis (19). These studies to a certain extent illustrate that the DEmiRs we identified have potential research value in diseases, especially cancer. In addition, these results also need to be further verified by later work.
Similarly, the lncRNA found in this article has not been fully reported in previous studies. It is reported that knockdown of lncRNA SCAMP1 suppressed malignant biological behaviors of glioma cells through regulating the miR-499a-5p/LMX1A/NLRC5 pathway (20). Additionally, SCAMP1 could be bound with miR-137 and accelerate the progression of ovarian cancer (OC) (21). Zhang, Xu (22) constructed a completing endogenous RNA (ceRNA) to explore the molecular mechanism of cisplatin (DDP) resistance in non-small cell lung cancer (NSCLC) cells. They found that MSTRG51053.2 lncRNA may be used as ceRNA for miR-432-5p to regulate DDP resistance in non-small cell lung cancer.
According to the recommendations from the international association (23), SNRI–duloxetine, venlafaxine, tricyclic antidepressants, and Gabapentin, pregabalin are recommended for first-line; while Capsaicin 8% patches, Lidocaine (lignocaine) patches, and Tramadol are recommended for second-line; and the strong opioids are recommended for the third line. Most of the drugs that were predicted in our study are arthritis, antiepileptic drugs, and sedatives, indicating that the identified genes were associated with the pathogenic mechanism of NP. However, it does not mean that we can use these predicated drugs in the clinic since there needs more research about these genes.
However, there are still some limitations of this study. First of all, we found that lncRNAs and microRNAs were related to neuropathic pain based on the GEO database, but it still needs to be verified by PCR analysis or immunoblotting. Secondly, the lncRNA-microRNAs-mRNA network constructed in our work could not indicate whether these RNAs co-express altogether in the same tissue. Finally, the specificity of the identified DElnc, DEmiRs and DEGs of neuropathic pain needs to be verified in further study.