An exploratory study on the mechanism of Huangqi Guizhi Wuwu Decoction in the treatment of neuropathic pain

Paeoniflorin regulates microglia-astrocyte crosstalk, inhibits inflammatory response, and alleviates neuropathic pain through HSP90AA1/HMGB1 signaling pathway

Given the unclear, complex pathogenesis of neuropathic pain and the potential of paeoniflorin in relieving neuropathic pain, this study aimed to further clarify the therapeutic effect of paeoniflorin on neuropathic pain and to preliminarily explore the possible protective mechanisms of paeoniflorin. Chronic constrictive injury-induced Sprague Dawley rats and lipopolysaccharide-induced BV-2 cells were used for in vivo and in vitro experiments, respectively. The exosome uptake assay of mouse astrocytes (PKH-67 fluorescent labeling) and the mechanical nociceptive assay (the von Frey fibrous filaments) were performed. The effects of paeoniflorin and its downstream mechanisms on microglial and astrocyte activation, inflammation-associated proteins and exosome marker were determined. Paeoniflorin alleviated mechanical abnormal pain, decreased levels of ionized calcium binding adapter molecule-1 (Iba-1), glial fibrillary acidic protein, Heat Shock Protein 90 Alpha Family Class A Member 1 (HSP90AA1, inflammatory factor) and High Mobility Group Box 1 (HMGB1, inflammation-related protein), and inhibited neuronal apoptosis in chronic constrictive injury rats or lipopolysaccharide-induced BV-2 cells. However, these effects were offset by HSP90AA1 overexpression in lipopolysaccharide-induced BV-2 cells. Exosomes of BV-2 cells could be absorbed by mouse astrocytes. In addition, HSP90AA1 overexpression reversed the effects of paeoniflorin on HMGB1 expression and inflammatory factors and proteins in mouse astrocytes co-cultured with exosome. Collectively, paeoniflorin alleviates neuropathic pain and inhibits inflammatory responses in chronic constrictive injury by modulating microglia-astrocyte crosstalk through HSP90AA1/HMGB1 pathways, which further evidences the potential of paeoniflorin in the treatment of neuropathic pain.

The mechanism of Taohong Siwu decoction in treating chemotherapy-induced peripheral neuropathy: a network pharmacology and molecular docking study

Background

Taohong Siwu decoction (THSWD) is a classic traditional Chinese medicine (TCM) formula known for its effects in promoting blood circulation, removing blood stasis, and rejuvenating energy. There have been clinical reports of THSWD treating chemotherapy-induced peripheral neuropathy (CIPN) caused by paclitaxel. We conducted a network pharmacology and molecular docking analysis to further clarify the molecular mechanisms by which THSWD exerts its protective effects against CIPN.

Methods

Chemical components of THSWD and their corresponding targets were obtained through the traditional Chinese medicine systems pharmacology database and analysis platform (TCMSP), and related targets of CIPN were searched in disease databases including Online Mendelian Inheritance in Man (OMIM), Therapeutic Target Database (TTD), GeneCards, and DrugBank. Common targets between THSWD and CIPN were identified using Venn diagrams. A protein-protein interaction (PPI) network was constructed using Search Tool for the Retrieval of Interacting Genes/Proteins (STRING), which was followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. AutoDock and PyMOL were used for the molecular docking validation of the key components of THSWD with core targets.

Results

At total of 69 chemical components of THSWD were identified, corresponding to 856 targets; 2,297 targets were associated with CIPN, with an intersection of 105 common targets. PPI analysis identified eight core targets: MYC, TNF, MAPK14, AKT1, ESR1, RELA, TP53, and HSP90AA1; KEGG enrichment analysis implicated signaling pathways such as PI3K-Akt, NF-κB, and HIF-1, etc. Molecular docking results indicated that the selected active components and their corresponding target proteins have good binding activity.

Conclusions

Through network pharmacology, this study found that THSWD has significant advantages in treating CIPN. By analyzing potential core targets, biological functions, and involved signaling pathways, we clarified the potential molecular biological mechanisms involved in THSWD's treatment effect. This study provides a theoretical basis for the clinical application of THSWD in treating CIPN.

Urine-derived mesenchymal stem cells-derived exosomes enhances survival and proliferation of aging retinal ganglion cells

OBJECTIVES

This study was designed to investigate to test the effect of exosomes from urine-derived mesenchymal stem cells (USCs) on the survival and viability of aging retinal ganglion cells (RGCs), and explored the preliminary related mechanisms.

METHODS

Primary USCs were cultured and identified by immunofluorescence staining. Aging RGCs models were established by D-galactose treatment and identified by β-Galactosidase staining. After treatment with USCs conditioned medium (with USCs removal), flow cytometry was performed to examine the apoptosis and cell cycle of RGCs. Cell viability of RGCs was detected by Cell-counting Kit 8 (CCK8) assay. Moreover, gene sequencing and bioinformatics analysis were applied to analyze the genetic variation after medium treatment in RGCs along with the biological functions of differentially expressed genes (DEGs).

RESULTS

The number of apoptotic aging RGCs was significantly reduced in USCs medium-treated RGCs. Besides, USCs-derived exosomes exert significant promotion on the cell viability and proliferation of aging RGCs. Further, sequencing data analyzed and identified DEGs expressed in aging RGCs and aging RGCs treated with USCs conditioned medium. The sequencing outcomes demonstrated 117 upregulated genes and 186 downregulated genes in normal RGCs group vs aging RGCs group, 137 upregulated ones and 517 downregulated ones in aging RGCs group vs aging RGCs + USCs medium group. These DEGs involves in numerous positive molecular activities to promote the recovery of RGCs function.

CONCLUSIONS

Collectively, the therapeutic potentials of USCs-derived exosomes include suppression on cell apoptosis, enhancement on cell viability and proliferation of aging RGCs. The underlying mechanism involves multiple genetic variation and changes of transduction signaling pathways.