Mechanism of Qingxuan Runmu Yin in the treatment of dry eye based on transcriptomics and network pharmacology

AIM: To investigate the mechanism of action of Qingxuan Runmu Yin(QRY)in the treatment of dry eye(DE)based on transcriptomics and network pharmacology, and to validate the efficacy and key targets of QRY through a animal model of DE.METHODS:RNA-sequencing(RNA-seq)technology was used to detect differentially expressed genes(DEGs)between mice in the DE group and mice in the normal control group, the active ingredients and potential targets of QRY were screened through database, and gene ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis were carried out after overlapping the results and obtaining key targets. Additionally, “drug-component-target signaling pathways” network was built and the protein-protein interaction(PPI)was analyzed. Mice were examined for Schirmer I test(SⅠt), tear film breakup time(BUT), and corneal fluorescein staining(FL)every 7 d from the beginning of the animal experiments. Hematoxylin-eosin staining(HE)was performed to observe pathologic changes in mouse corneal tissues. Enzyme linked immunosorbent assay(ELISA), Western blot and quantitative real-time polymerase chain reaction(qRT-PCR)were performed to verify the mRNA and protein expression levels of the core targets in mouse corneal tissues.RESULTS:Totally 2 234 DEGs, 233 active ingredients and 457 related targets of QRY were collected, with a total of 64 key targets obtained. GO function and KEGG pathway results showed that QRY was closely related to inflammatory mediators, and 19 core targets such as interleukin-1β(IL-1β)were screened by PPI network construction; SⅠt, BUT and FL results in the QRY group were statistically significantly different compared with the model group(all P<0.05); HE staining showed that corneal epithelial cell stratification was disordered and the corneal morphology was changed in the model group. However, QRY treatment significantly improved corneal morphology and disordered stratification, with a close morphology to the blank group; ELISA, Western blot and qRT-PCR results showed that the protein expression and RNA levels of IL-1β, IL-6, and tumor necrosis factor(TNF-α)in the QRY group showed a decreasing trend compared with the model group.CONCLUSION: Through the combination of multiple components, multiple targets and multiple pathways, QRY regulated the targets such as IL-6, IL-1β and TNF through quercetin and other main components, thereby inhibiting AGE-RAGE/TNF/IL-17 and other signaling pathways, thus achieving the treatment on DE.