Clin Transl Med. 2026 Sep;16(9):e70752. doi: 10.1002/ctm2.70752.
ABSTRACT
RATIONALE: Circular RNAs (circRNAs) are stable, tissue- and developmental-stage-specific regulators of gene expression and candidate disease biomarkers. Their expression profile in abnormal lung development in congenital diaphragmatic hernia (CDH) is unknown.
OBJECTIVE: To evaluate circRNA expression profile in CDH-associated abnormal lung development.
METHODS: We profiled circRNAs in rat CDH and control lungs at embryonic day (E)15 and E21 by microarray. We validated identified circRNAs using back‒splice junction amplicon sequencing, RT-qPCR and in situ hybridisation. We modified a circRNA function prediction tool to predict circRNA::micro(mi)RNA::messenger(m)RNA interactions and compared these with Oxford Nanopore RNA sequencing and existing human CDH datasets.
MEASUREMENTS AND MAIN RESULTS: Microarrays revealed a unique circRNA biosignature during CDH lung development. CircAnp32e was expressed in a sex-specific and spatiotemporal expression pattern in the epithelium at E15. The predicted mature sequence of circAnp32e overlapped 90% with its human orthologue. circRNA::miRNA::mRNA interaction networks at E15 and E21 revealed enrichment in inflammation/infection, smooth muscle cell function, cell proliferation/cell cycle regulation and response to hypoxia pathways. Parental genes of differentially expressed circRNAs at E15 enriched pathways linked to cell proliferation/cell cycle/cancer, while at end-gestation, inflammation and cardiovascular processes were also overrepresented. Rat and human CDH lungs showed overlapping pathways with additional enrichment for RNA processing and protein binding/modification in humans. In a human bronchial epithelial (BEAS-2B) nitrofen-injury model, ANP32E and circANP32E were downregulated, and the predicted let-7 target was significantly dysregulated.
CONCLUSION: A unique circRNA signature during abnormal lung development in CDH may mediate inflammatory responses, smooth muscle cell function and cell proliferation regulation via miRNA sponging. Overlap of downstream pathways in rat and human CDH suggests conserved functions across species. This circRNA biosignature defines strong candidate biomarkers for CDH and a basis for future prospective prenatal investigation.
PMID:42723598 | DOI:10.1002/ctm2.70752