Night-restricted feeding preserves the ovarian circadian rhythm of IL-17 and promotes follicular development in prepubertal and pubertal rabbits

BACKGROUND: Irregular sleep and eating patterns in modern lifestyles may disrupt reproductive rhythms, thereby impairing reproductive function in adult women. In livestock production, improper management may disturb livestock eating and activity rhythms, thereby reducing reproductive performance. However, whether disruptions in feeding times during the growth stage affect pubertal follicular development via the ovarian circadian rhythm regulation remains unclear. RESULTS: In this study, rabbits were assigned to daytime feeding (DF) and night-restricted feeding (NRF) groups. At day 84, ovarian circadian transcriptome (4-hour intervals over a 24-hour period) revealed that NRF induced a circadian oscillation of the IL-17 signaling pathway, with peak expression occurring at night. Furthermore, NRF significantly accelerated the timing of puberty onset. At day 145, NRF promoted follicular development and enhanced granulosa cell proliferation. Ovarian diurnal transcriptome analysis (12-hour intervals over a 24-hour period) demonstrated that feeding time exerted sustained regulatory effects on the IL-17 signaling pathway. Notably, ovarian IL-17 protein levels in the NRF group exhibited a diurnal difference, with lower levels during the day and higher levels at night. In vitro experiments further demonstrated that rhythmic IL-17 stimulation, simulating the NRF group, promotes granulosa cell proliferation and enhances the rhythmic expression of core clock genes (BMAL1, CLOCK) as well as the cell cycle regulator WEE1. CONCLUSION: Feeding time synchronized with endogenous circadian rhythms maintains the ovarian IL-17 rhythmicity, may contribute to promoting granulosa cell proliferation, driving follicular development, and ensuring timely pubertal onset. These findings suggest that the impact of feeding time on the onset of puberty and follicular development may be linked to the circadian rhythm of ovarian inflammatory signaling, offering new insights into the protection of reproductive health during puberty and the prevention of reproductive disorders via dietary timing adjustments.