Mechanism of Xiezhuo Jiedu Recipe in Preventing Colorectal Adenoma in Mice Through miRNA-34a-5p/PI3K/Akt Signalling Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveKey microRNAs （miRNAs） of colorectal adenoma （CRA） were identified and analyzed by bioinformatics methods， and differentially expressed genes （DEGs） were screened to construct regulatory relationships. The mechanism of Xiezhuo Jiedu recipe in preventing CRA was speculated and verified by animal experiments. MethodThe miRNAs dataset GSE50194 was obtained from the Gene Expression Omnibus （GEO） database of intestinal mucosal tissue of CRA patients， and the differentially expressed miRNAs were screened by GEO2R and Excel. TargetScan， miRTarbase， and miRDB databases were used to predict the target genes of the differentially expressed miRNAs， and an intersection was obtained. Key DEGs were screened through the STRING database and Cytoscape software， and the TRRUST database was used to predict downstream binding transcription factors （TFs）. The mRNA intersection was enriched by gene ontology （GO） and Kyoto encyclopedia of genes and genomes （KEGG） in the Metascape database. DIANA TOOLS were applied to perform KEGG enrichment analysis of key miRNAs， and the key signaling pathways were selected for animal experiments. In animal experiments， the CRA mice model was established by using sodium glycan sulfate （DSS） drinking combined with intraperitoneal injection of azomethane oxide （AOM）， and Xiezhuo Jiedu recipe and aspirin were given by intragastric administration at the same time. The experiment lasted for nine weeks. The pathological changes in intestinal tissue were observed by hematoxylin-eosin （HE） staining. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression of miR-34a-5p in adenoma tissue. Protein expression levels of phosphatidylinositol 3-kinase （PI3K）， protein kinase B （Akt）， phosphoryl-PI3K （p-PI3K）， phosphoryl-Akt （p-Akt）， and B cell lymphoma （Bcl）-2 were detected by Western blot. The expression of Cyclin D1 （CCND1） was detected by immunohistochemistry （IHC）. In situ terminal transferase labeling （TUNEL） was used to detect apoptosis of adenoma tissue cells. ResultThe GEO database screened the GSE50194 dataset， and miR-34a-5p was selected as the research object from CRA and normal tissue. A total of 93 DEGs were selected. Among them， GO and KEGG enrichment analyses were closely related to biological processes such as transcriptional regulatory complex， RNA polymerase Ⅱ transcriptional regulatory complex， enzyme-linked receptor protein signaling pathway， and DNA-binding transcriptional activator activity， cancer pathway， PI3K/Akt pathway， etc. miR-34a-5p is mainly enriched in PI3K/Akt， cell cycle， and colorectal cancer pathways. Five key DEGs were screened out through the Matescape database， among which Bcl-2 and CCND1 were the key DEGs of miR-34a-5p. Further screening of the TFs of key DEGs revealed that E2F transcription factor 1 （E2F1） and tumor protein P53 （TP53） were the main TFs of Bcl-2 and CCND1. Animal experiments showed that Xiezhuo Jiedu recipe could effectively up-regulate mRNA level of miR-34a-5p， down-regulate the expression of PI3K， Akt， Bcl-2， p-PI3K， and p-Akt proteins in the intestinal tissue of CRA mice， down-regulate the positive expression rate of CCND1， and increase the apoptosis rate of intestinal epithelial cells. ConclusionIt is speculated that Xiezhuo Jiedu recipe may inhibit the abnormal proliferation and promote the apoptosis of intestinal epithelial cells in CRA mice by regulating the miR-34a-5p/PI3K/Akt signaling pathway， thus playing a role in the prevention of CRA.