Expression profile of circular RNAs in continuous light-induced ovarian dysfunction

Area of Science:

• Reproductive Biology
• Molecular Endocrinology
• Chronobiology

Background:

• Continuous light exposure is a known disruptor of reproductive function.
• Circular RNAs (circRNAs) are emerging as key regulators in various biological processes, including reproductive health.
• The specific role of circRNAs in light-induced ovarian dysfunction remains largely unexplored.

Purpose of the Study:

• To investigate the differential expression profiles of circRNAs in rat ovaries under continuous light exposure.
• To elucidate the potential molecular mechanisms by which circRNAs contribute to ovarian dysfunction induced by light.
• To identify novel circRNAs and pathways involved in the pathophysiology of ovarian dysfunction.

Main Methods:

• High-throughput sequencing to profile circRNA transcriptomes in rat ovaries under continuous light (L/L) versus control (L/D) conditions.
• Bioinformatic analyses including Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment.
• Construction of circRNA-microRNA-messenger RNA (mRNA) networks to predict functional interactions.
• Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) for validation of circRNAs and circadian rhythm genes.

Main Results:

• 305 differentially expressed circRNAs (DEcircRNAs) were identified, with 211 upregulated and 94 downregulated.
• Bioinformatic analyses suggested that DEcircRNAs interact with microRNAs involved in key ovarian dysfunction pathways (e.g., androgen receptor signaling, GnRH signaling).
• Specific circRNAs (rno_circ:chr2:86868285-86964272 and rno_circ:chr1:62330221-62360073) were implicated in ovarian dysfunction pathophysiology.
• Continuous light reduced expression of circadian rhythm genes (CLOCK, BAML1, PER1, PER2) and altered apoptosis-related genes (Bax, Bcl-2, Caspase3).

Conclusions:

• Altered circRNA expression profiles in rat ovaries are associated with continuous light-induced ovarian dysfunction.
• These DEcircRNAs and their associated pathways represent potential molecular targets for understanding and treating ovarian dysfunction.
• The study provides novel insights into the molecular mechanisms underlying circadian rhythm disruption and its impact on ovarian health.