橄榄苦苷对须癣毛癣菌的抗菌作用及机制分析

Inhibitory activity and mechanism of oleuropein against Trichophyton mentagrophytes

摘要:

【背景】须癣毛癣菌是一种常见的皮肤浅部致病菌，由其引发的皮肤癣菌病在人群中发病率较高，对人们的身体健康构成了极大的威胁。【目的】探究橄榄苦苷单体对须癣毛癣菌的抑菌作用及机制。【方法】测定橄榄苦苷对须癣毛癣菌的最小抑菌浓度(minimum inhibitory concentration, MIC)和最小杀菌浓度(minimum bactericidal concentration, MBC)，基于RNA-Seq测序技术对橄榄苦苷作用后的须癣毛癣菌进行转录测序，对测序序列进行质量评价与信息注释。使用DESeq2软件筛选差异表达基因(differentially expressed gene, DEG)，然后进行GO与KEGG显著性富集分析，最后进行RT-qPCR验证。【结果】橄榄苦苷对须癣毛癣菌的MIC为400 μg/mL，MBC为800 μg/mL。RNA-seq测序结果显示，相较于未给药处理组，给药处理组共筛选出534个差异表达基因；其中上调表达401个，下调表达133个。序列已提交至NCBI的Sequence read archive (SRA)数据库，登录号为PRJNA1091040。DEG主要富集在氧化磷酸化、氨基酸代谢、乙醛酸和二羧酸代谢等通路上，并且相关基因均有显著性表达(P<0.05)。RT-qPCR验证结果与转录组学表达趋势一致，表明RNA-seq测序结果可信度高。【结论】探究了橄榄苦苷对须癣毛癣菌产生抑制作用的分子机制，为进一步揭示橄榄苦苷的抑菌作用机理提供了理论基础。

Abstract:

[Background] Trichophyton mentagrophytes is a common superficial skin pathogen, and dermatophytosis caused by this pathogen has a high incidence, posing a threat to human health. [Objective] To investigate the inhibitory activity and mechanism of oleuropein against T. mentagrophytes. [Methods] We determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). RNA-Seq was performed for T. mentagrophytes treated with oleuropein and the obtained sequences were subjected to quality evaluation and information annotation. DESeq2 was used to identify the differentially expressed genes (DEGs), which were then subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. RT-qPCR was conducted to validate the results. [Results] The MIC and MBC of oleuropein against T. mentagrophytes were 400 μg/mL and 800 μg/mL, respectively. A total of 534 DEGs were identified between the treatment group and the control group, including 401 genes with upregulated expression and 133 genes with downregulated expression. The sequence has been submitted to Sequence read archive (SRA) of the NCBI, with the accession number PRJNA1091040. These DEGs were mainly enriched in pathways related to oxidative phosphorylation, amino acid metabolism, and glyoxylate and dicarboxylate metabolism, with significant expression (P<0.05). The RT-qPCR results were consistent with the results from transcriptomics, demonstrating the reliability of RNA-Seq findings. [Conclusion] We investigated the mechanism underlying the inhibitory effect of oleuropein on T. mentagrophytes, providing a theoretical basis for deciphering the antifungal mechanism of oleuropein.