Women and Children's Hospital of Chongqing Medical University (Chongqing Health Center for Women and Children), Chongqing, China.
Chongqing Key Laboratory of Maternal and Fetal Medicine, Chongqing Medical University, Chongqing, China.
Front Immunol. 2022 Aug 22;13:879487. doi: 10.3389/fimmu.2022.879487. eCollection 2022.
Preterm birth (PTB) is a multifactorial syndrome that seriously threatens the health of pregnant women and babies worldwide. Recently, circular RNAs (circRNAs) have been understood as important regulators of various physiological and pathological processes. However, the expression pattern and potential roles of circRNAs in PTB are largely unclear.
In this study, we extracted and analyzed the circRNA expression profiles in maternal and fetal samples of preterm and term pregnancies, including maternal plasma, maternal monocytes, myometrium, chorion, placenta, and cord blood. We identified the circRNAs which is associated with PTB in different tissues and explored their relationships from the perspective of the overall maternal-fetal system. Furthermore, co-expression analysis of circRNAs and mRNAs, target microRNAs (miRNAs), and RNA-binding proteins (RBPs), provided new clues about possible mechanisms of circRNA function in PTB. In the end, we investigated the potential special biofunctions of circRNAs in different tissues and their common features and communication in PTB.
Significant differences in circRNA types and expression levels between preterm and term groups have been proved, as well as between tissues. Nevertheless, there were still some PTB-related differentially expressed circRNAs (DECs) shared by these tissues. The functional enrichment analysis showed that the DECs putatively have important tissue-specific biofunctions through their target miRNA and co-expressed mRNAs, which contribute to the signature pathologic changes of each tissue within the maternal-fetal system in PTB (e.g., the contraction of the myometrium). Moreover, DECs in different tissues might have some common biological activities, which are mainly the activation of immune-inflammatory processes (e.g., interleukin1/6/8/17, chemokine, TLRs, and complement).
In summary, our data provide a preliminary blueprint for the expression and possible roles of circRNAs in PTB, which lays the foundation for future research on the mechanisms of circRNAs in PTB.
早产（PTB）是一种多因素综合征，严重威胁着全球孕妇和婴儿的健康。最近，环状 RNA（circRNA）被认为是多种生理和病理过程的重要调节因子。然而，circRNA 在 PTB 中的表达模式和潜在作用在很大程度上尚不清楚。
在这项研究中，我们提取并分析了来自早产和足月妊娠的母胎样本（包括母血浆、母单核细胞、子宫肌层、绒毛膜、胎盘和脐带血）中的 circRNA 表达谱。我们鉴定了与不同组织中 PTB 相关的 circRNAs，并从整体母胎系统的角度探讨了它们的关系。此外，circRNA 和 mRNA、靶 microRNA（miRNA）和 RNA 结合蛋白（RBP）的共表达分析为 circRNA 在 PTB 中的功能提供了可能的机制的新线索。最后，我们研究了不同组织中 circRNA 的潜在特殊生物功能及其在 PTB 中的共同特征和通讯。
证明了早产和足月组以及不同组织之间 circRNA 类型和表达水平存在显著差异，但仍有一些组织共享与 PTB 相关的差异表达 circRNA（DECs）。功能富集分析表明，通过其靶 miRNA 和共表达的 mRNAs，DECs 可能具有重要的组织特异性生物功能，这些功能有助于母胎系统中每个组织的特征性病理变化，如子宫肌层的收缩。此外，不同组织中的 DECs 可能具有一些共同的生物学活性，主要是免疫炎症过程的激活（如白细胞介素 1/6/8/17、趋化因子、TLR 和补体）。
总之，我们的数据为 circRNA 在 PTB 中的表达和可能作用提供了一个初步蓝图，为未来研究 circRNA 在 PTB 中的机制奠定了基础。
