Shao Binghao, Wang Ziyang, Luo Pengna, Du Pengfei, Zhang Xiangli, Zhang Huaiyong, Si Xuemeng, Ma Sen, Chen Wen, Huang Yanqun
College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, 450002, China.
BMC Genomics. 2025 Feb 15;26(1):148. doi: 10.1186/s12864-025-11347-w.
Circular RNAs (circRNAs) are stable, covalently closed non-coding RNAs formed by reverse splicing of precursor mRNA. They play critical roles in various biological processes, including insulin secretion and metabolism. However, their function in avian skeletal muscle's response to insulin remains poorly understood. This study aimed to comprehensively identify insulin-responsive circRNAs and explore their temporal and breed-specific regulation in poultry.
Using strand-specific RNA sequencing (ssRNA-Seq) on the pectoralis muscles of both Arbor Acres (AA) broilers and Silky fowls following insulin administration (5 IU/kg.BW, PBS as control). We identified 2,027 muscle circRNAs. Insulin-responsive circRNAs were detected in Silky fowls (29) and broilers (45) at 120 min, and in broilers (20) at 15 min post-injection. These circRNAs are enriched in processes such as exocrine pancreas development, response to exogenous stimuli, and regulation of intracellular signal transduction, likely mediated through a circRNA-miRNA network. Fewer insulin-responsive circRNAs were shared between time points in broilers (1) or between breeds (3) at 120 min. We further characterized a conserved insulin-responsive circRNA (circINSR), formed by exon 2 of the Insulin Receptor (INSR). The circINSR showed a similar spatiotemporal expression pattern to INSR, but exhibited distinct changes post-insulin administration. In broilers, INSR expression was dynamically modulated, while circINSR was downregulated only at 15 min (P < 0.01). Conversely, glucose did not change muscle circINSR but increased INSR at 10 min (P < 0.01). Energy restriction significantly downregulated circINSR (P < 0.01) without affecting INSR levels, and pyruvate had no effect on either circINSR or INSR levels.
This study reveals the dynamic and breed-specific roles of circRNAs, particularly circINSR, in avian skeletal muscle's response to insulin. The distinct regulation of circINSR and INSR under various metabolic conditions suggests a complex regulatory mechanism. These findings provide novel insights into the molecular basis of insulin signaling in avian species and highlight the potential of circRNAs as biomarkers for metabolic regulation.
环状RNA（circRNAs）是由前体mRNA反向剪接形成的稳定、共价闭合的非编码RNA。它们在包括胰岛素分泌和代谢在内的各种生物学过程中发挥关键作用。然而，它们在禽类骨骼肌对胰岛素反应中的功能仍知之甚少。本研究旨在全面鉴定胰岛素反应性circRNAs，并探索其在家禽中的时间和品种特异性调控。
对艾维茵（AA）肉鸡和丝羽乌骨鸡的胸肌进行链特异性RNA测序（ssRNA-Seq），胰岛素给药后（5IU/kg体重，以PBS作为对照）。我们鉴定出2027个肌肉circRNAs。在注射后120分钟，在丝羽乌骨鸡（29个）和肉鸡（45个）中检测到胰岛素反应性circRNAs，在注射后15分钟，在肉鸡（20个）中检测到。这些circRNAs在外分泌胰腺发育、对外源刺激的反应和细胞内信号转导的调控等过程中富集，可能是通过circRNA-miRNA网络介导的。在120分钟时，肉鸡不同时间点（1个）或不同品种（3个）之间共享的胰岛素反应性circRNAs较少。我们进一步鉴定了一种由胰岛素受体（INSR）外显子2形成的保守的胰岛素反应性circRNA（circINSR）。circINSR显示出与INSR相似的时空表达模式，但在胰岛素给药后表现出明显变化。在肉鸡中，INSR表达受到动态调节，而circINSR仅在15分钟时下调（P<0.01）。相反，葡萄糖对肌肉circINSR没有影响，但在10分钟时增加了INSR（P<0.01）。能量限制显著下调了circINSR（P<0.01），而不影响INSR水平，丙酮酸对circINSR和INSR水平均无影响。
本研究揭示了circRNAs，特别是circINSR，在禽类骨骼肌对胰岛素反应中的动态和品种特异性作用。circINSR和INSR在各种代谢条件下的不同调控表明存在复杂的调控机制。这些发现为禽类胰岛素信号传导的分子基础提供了新的见解，并突出了circRNAs作为代谢调控生物标志物的潜力。
