Xie Xiaolu, Chen Zhihao, Han Mingxiao, Wang Xi, Wang Min, Lv Jingnan, Xie Xiaofang, Zhai Yaxuan, Li Liubing, Du Hong, Xie Zonggang, Zhang Haifang
Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, China.
Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, China.
Microb Pathog. 2022 Apr;165:105466. doi: 10.1016/j.micpath.2022.105466. Epub 2022 Mar 2.
Intracellular Staphylococcus aureus (S. aureus) infection is generally persistent, recurrent and difficult to treat due to the poor availability of antibiotics within macrophages cells and the lack of ideal diagnostic markers. Circular RNAs (circRNAs), with covalently closed circular structures, exists in the serum stably and is not easily degraded by nucleases. Besides, circRNAs play a pivotal in the eukaryotic regulation of genes expression and served as biomarkers in variety disease including microbial infections. However, the function of host circRNAs in intracellular S. aureus infection remains largely unclear.
In this study, the circRNAs expression profile was investigated by RNA sequencing technology in both S. aureus-infected THP-1 derived macrophages and mock control cells. The differentially expressed circRNAs (DE circRNAs) with a fold-change >1.5 (p < 0.05) are analyzed using functional pathway clustering prediction. Then, RT-qPCR was performed to verify the top 2 up-regulated circRNAs in the THP-1 cell and human serum samples so as to evaluate the value of circRNAs for S. aureus diagnosis.
An intracellular survival THP-1 derived macrophages model of S. aureus infection was established. A total of 5,299 circRNAs were identified in human THP-1 derived macrophages infected with intracellular S. aureus. There were 61 DE circRNAs with a fold-change >1.5 (p < 0.05) after S. aureus infection. Among them, 22 circRNAs were up-regulated while 39 circRNAs down-regulated. GO and KEGG pathway analysis demonstrated that DE circRNAs were enriched in the processes such as Neurotrophin, Pyruvate metabolism and Notch signaling pathway. Moreover, hsa_circ_0000311 and chr13:43500472-43544806-(novel) were verified to be significantly upregulated in THP-1 derived macrophages and human serum samples between two groups. Finally, the networks of circRNA-miRNA-mRNA based on these two circRNAs were constructed respectively.
Our study provides the first profile analysis of host circRNAs involved in intracellular S. aureus infection, which may serve as biomarkers for S. aureus diagnosis and contribute to the understanding of S. aureus evasion mechanisms.
细胞内金黄色葡萄球菌感染通常具有持续性、复发性且难以治疗，这是由于巨噬细胞内抗生素的可利用性差以及缺乏理想的诊断标志物。环状RNA（circRNAs）具有共价闭合的环状结构，在血清中稳定存在且不易被核酸酶降解。此外，circRNAs在真核基因表达调控中起关键作用，并可作为包括微生物感染在内的多种疾病的生物标志物。然而，宿主circRNAs在细胞内金黄色葡萄球菌感染中的功能仍 largely不清楚。
在本研究中，通过RNA测序技术研究了金黄色葡萄球菌感染的THP-1衍生巨噬细胞和模拟对照细胞中的circRNAs表达谱。使用功能途径聚类预测分析差异表达的circRNAs（DE circRNAs），其变化倍数>1.5（p < 0.05）。然后，进行RT-qPCR以验证THP-1细胞和人血清样本中上调的前2个circRNAs，以评估circRNAs对金黄色葡萄球菌诊断的价值。
建立了金黄色葡萄球菌感染的细胞内存活THP-1衍生巨噬细胞模型。在感染细胞内金黄色葡萄球菌的人THP-1衍生巨噬细胞中总共鉴定出5299个circRNAs。金黄色葡萄球菌感染后有61个DE circRNAs，变化倍数>1.5（p < 0.05）。其中，22个circRNAs上调，39个circRNAs下调。GO和KEGG途径分析表明，DE circRNAs在神经营养因子、丙酮酸代谢和Notch信号通路等过程中富集。此外，hsa_circ_0000311和chr13:43500472-43544806-（新的）在两组之间的THP-1衍生巨噬细胞和人血清样本中被验证为显著上调。最后，分别基于这两个circRNAs构建了circRNA-miRNA-mRNA网络。
我们的研究首次提供了参与细胞内金黄色葡萄球菌感染的宿主circRNAs的谱分析，这可能作为金黄色葡萄球菌诊断的生物标志物，并有助于理解金黄色葡萄球菌的逃避机制。
