Integrated analysis of the responses of a circRNA-miRNA-mRNA ceRNA network to heat stress in rainbow trout (Oncorhynchus mykiss) liver

Background: With the intensification of global warming, rainbow trout (Oncorhynchus mykiss) suffer from varying degrees of thermal stimulation, leads to mass mortality, which severely restrict the development of aquaculture. Understanding the molecular regulatory mechanisms of rainbow trout under heat stress is useful to develop approaches to relieve symptoms. Results: Changes in nonspecific immune parameters revealed that a strong stress response was caused in rainbow trout at 24 degrees C, so we performed multiple transcriptomic analyses of rainbow trout liver under heat stress (HS, 24 degrees C) and control conditions (CG, 18 degrees C). A total of 324 DEcircRNAs, 105 DEmiRNAs, and 1885 DEmRNAs were identified. A ceRNA regulatory network was constructed and a total of 301 circRNA-miRNA and 51 miRNA-mRNA negative correlation pairs were screened, and three regulatory correlation pairs were predicted: novel_circ_003889 - novel-m0674-3p - hsp90ab1, novel_circ_002325 - miR-18-y - HSPA13 and novel_circ_002446 - novel-m0556-3p - hsp70. Some target genes involved in metabolic processes, biological regulation or response to stimulus were highly induced at high temperatures. Several important pathways involved in heat stress were characterized, such as protein processing in the ER, the estrogen signaling pathway, and the HIF-1 signaling pathway. Conclusions: These results extend our understanding of the molecular mechanisms of the heat stress response and provide novel insight for the development of strategies that relieve heat stress.

Automated summary

The study investigated the transcriptomic changes in rainbow trout under heat stress and identified a strong stress response at high temperatures. A ceRNA regulatory network was constructed, and target genes involved in metabolic processes, biological regulation, and response to stimuli were highly induced. Several important pathways related to heat stress were characterized, providing novel insights for the development of strategies to alleviate heat stress.