Abstract: BACKGROUND: It has been shown that long non-coding RNA (lncRNA) plays an important role in the development and progression of cardiac diseases, and whether it is involved in daisy leaf gentianone antagonizing adriamycin-induced cardiac injury in mice has not been reported.
OBJECTIVE: To screen differentially expressed lncRNAs in myocardial tissue of mice with adriamycin-induced myocardial injury antagonized with daisy leaf gentianone and conduct a bioinformatics analysis.
METHODS: Forty-eight C57 mice were randomly divided into normal group, model group, daisy leaf gentianone group and positive drug group, with 12 mice in each group. The mice in the model group, daisy leaf gentianone group and positive drug group were injected with adriamycin intraperitoneally once every other day for 8 times in total. The daisy leaf gentianone group and positive drug group were given daisy leaf gentianone suspension and captopril solution by gavage based on adriamycin injection once a day for 21 continuous days. After medication, mice in each group underwent electrocardiogram examination and the myocardial tissue was taken for pathomorphological observation. At the same time, high-throughput sequencing analysis of mouse myocardial tissue was carried out, differentially expressed lncRNAs were screened, and target genes were predicted for differentially expressed lncRNAs. Gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes signaling pathway analyses of target genes were performed.
RESULTS AND CONCLUSION: The ST segment of the electrocardiogram of mice in the model group was significantly elevated. Compared with the model group, the degree of ST-segment elevation on the electrocardiogram was reduced in the daisy leaf gentianone group. Results from hematoxylin-eosin, Masson, and Sirius red staining indicated that in the model group, the myocardial cytoplasm was unevenly colored with varying shades of color, the integrity and continuity of myocardial fibers were poor, and a large number of collagen fibers were deposited. After treatment with gentianone daisy leaves, the abnormalities in myocardial tissue of mice were improved. The results of high-throughput sequencing analysis showed that compared with the model group, a total of 270 lncRNAs were identified in the myocardial tissue of mice in the daisy leaf gentianone group, including 165 up-regulated and 105 down-regulated lncRNAs. Combining the experimental results with related literature, three lncRNAs (NONMMUT149833.1, NONMMUT003237.2, and ENSMUST00000219015) and four related mRNAs (Alas2, Igf2, Acta1, and Cilp) were finally identified. The results of target gene prediction, gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes signaling pathway analyses showed that differentially expressed lncRNAs in myocardial tissue of mice with myocardial injury could regulate the expression of their target protein-coding genes through cis- and/or trans-regulation, and participate in regulating molecular functions and biological processes. To conclude, daisy leaf gentianone significantly improves cardiac function and partial lncRNA expression in mice with adriamycin-induced myocardial injury.

Key words: daisy leaf gentianone, myocardial injury, long non-coding RNA, bioinformatics, signaling pathway