Blocking of cytokines signalling attenuates evoked and spontaneous neuropathic pain behaviours in the paclitaxel rat model of chemotherapy-induced neuropathy

The Efficacy of Acupuncture in Chemotherapy-Induced Peripheral Neuropathy: Systematic Review and Meta-Analysis

Background: Chemotherapy-induced peripheral neuropathy (CIPN) has no cure, but acupuncture may provide relief through its known neuromodulation or neuroendocrine adjustment. This review aimed to assess the efficacy of acupuncture in treating CIPN. Method: A literature review following the PRISMA Statement was performed, searching 7 databases from inception through August 2019. All studies were clinical trials of the effect of acupuncture on CIPN. The methodological quality of these trials was assessed using Cochrane criteria; meta-analysis software (RevMan 5.2) was used to analyze the data. Data Sources: The databases searched were the following: MEDLINE (Ovid), Embase, Cochrane CENTRAL, Scopus, World Health Organization International Clinical Trials Registry Platform, CNKI (China National Knowledge Infrastructure), and Wanfang Med Online. Results: We examined 386 cancer patients from 6 randomized control trials, which had high quality, based on the modified Jadad scale. Meta-analysis showed that acupuncture led to significant improvements in pain scores (-1.21, 95% confidence interval [CI] = -1.61 to -0.82, P < .00001) and nervous system symptoms based on Functional Assessment of Cancer Therapy/Neurotoxicity questionnaire scores (-2.02, 95% CI = -2.21 to -1.84, P < .00001). No significant change was noted in nerve conduction velocity (1.58, 95% CI = -2.67 to 5.83, P = .47). Conclusion: Acupuncture can effectively relieve CIPN pain and functional limitation. The limited number of subjects warrants a larger scale study.

Peripheral sympathetic mechanisms in orofacial pain

Sympathetic nervous system (SNS) is a part of the autonomic nervous system which involuntarily regulates internal body functions. It appears to modulate the processing of nociceptive information. Many orofacial pain conditions involve inflammation of orofacial tissues and/or injury of nerve, some of which might be attributed to SNS. Thus, the aim of this review was to bring together the data available regarding the peripheral sympathetic mechanisms involved in orofacial pain. A clearer understanding of SNS–sensory interactions in orofacial pain may provide a basis for novel therapeutic strategies for conditions that respond poorly to conventional treatments.

Mechanism of MCP-1 in Acute Lung Injury and Advanced Therapy by Drug-Loaded Dextrin Nanoparticle

Objective. To observe the expression of monocyte chemotactic protein 1 (MCP-1) in acute lung injury (ALI) rat model, to characterize its effect on the development and progression of ALI, and to identify the potential new drug delivery approach during in vivo experiment. Method. The effects of different doses of lipopolysaccharide (LPS) on human pulmonary artery endothelial cells (HPAEC) were tested. For the animal experiments, thirty Sprague-Dawley (SD) rats were divided into physiological saline control group (NC group), the LPS model group (L group), the antagonist RS102895 combined with LPS group (R + L group), and the antagonist RS102895-loaded polyaldehyde dextran nanoparticles combined with LPS group (DNPR + L group). The blood gas analysis and dry/wet weight ratio were detected 24 hours after interventions. The levels of inflammatory factors, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), were tested by ELISA. The expression of monocyte chemoattractant protein-1 (MCP-1) in lung tissues was examined through Western blot, and the change of MCP-1 mRNA expression level was detected by performing RT-PCR. Result. LPS was responsible for inducing ALI in rats, and the degree of cell damage was dose-dependent. Blood gas analysis of L group showed that PaO2 and PaO2/FiO2 levels were significantly lower than those of the NC group (P<0.05), while the dry/wet weight ratio of lung tissues in L group increased (P<0.05). Inflammatory factors including TNF-α and IL-1β and the expression of MCP-1 in both protein and mRNA levels were higher in L group than in the NC group (P<0.05). The inhibition of the interaction between MCP-1 and chemokines receptor 2 (CCR2) by antagonist RS102895 can significantly alleviate the ALI in rats, which is accompanied by a significant decrease of inflammatory factors and MCP-1 expression (P<0.05). Compared with R + L group, treatment with DNPR and LPS combination significantly improved the condition of rats and decreased the level of TNF-α, IL-1β, and MCP-1 expression (P<0.05). Conclusion. In ALI, RS102895 can inhibit the MCP-1/CCR2 interaction, therefore, retarding the progress of ALI. Because of the high transfection efficiency of inhibitor RS102895packgaed by polyaldehyde dextran nanoparticles, this phenomenon particularly reached a significant level. The results imply new insights for the treatment of ALI.

Analyses of gene expression profiles in the rat dorsal horn of the spinal cord using RNA sequencing in chronic constriction injury rats

Background

Neuropathic pain is caused by damage to the nervous system, resulting in aberrant pain, which is associated with gene expression changes in the sensory pathway. However, the molecular mechanisms are not fully understood.

Methods

Wistar rats were employed for the establishment of the chronic constriction injury (CCI) models. Using the Illumina HiSeq 4000 platform, we examined differentially expressed genes (DEGs) in the rat dorsal horn by RNA sequencing (RNA-seq) between CCI and control groups. Then, enrichment analyses were performed for these DEGs using Gene Ontology (GO) function, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, Hierarchical Cluster, and protein-protein interaction (PPI) network.

Results

A total of 63 DEGs were found significantly changed with 56 upregulated (e.g., Cxcl13, C1qc, Fcgr3a) and 7 downregulated (e.g., Dusp1) at 14 days after CCI. Quantitative reverse-transcribed PCR (qRT-PCR) verified changes in 13 randomly selected DEGs. GO and KEGG biological pathway analyses showed that the upregulated DEGs were mostly enriched in immune response-related biological processes, as well as 14 immune- and inflammation-related pathways. The downregulated DEGs were enriched in inactivation of mitogen-activated protein kinase (MAPK) activity. PPI network analysis showed that Cd68, C1qc, C1qa, Laptm5, and Fcgr3a were crucial nodes with high connectivity degrees. Most of these genes which have previously been linked to immune and inflammation-related pathways have not been reported in neuropathic pain (e.g., Laptm5, Fcgr3a).

Conclusions

Our results revealed that immune and defense pathways may contribute to the generation of neuropathic pain after CCI. These mRNAs may represent new therapeutic targets for the treatment of neuropathic pain.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1316-0) contains supplementary material, which is available to authorized users.