Resveratrol attenuates prenatal X-ray-induced microcephaly and adult depression via SIRT1-mediated senescence suppression and TPH2/5-HT pathway restoration in mice

BACKGROUND: With increasing use of medical imaging (e.g., CT scans) and environmental radiation sources, over 2 % of pregnancies worldwide are inadvertently exposed to low-dose ionizing radiation (IR), raising urgent concerns about fetal neuroprotection. While prenatal IR is implicated in microcephaly and lifelong neuropsychiatric risks, prior studies have not resolved whether sirtuin-mediated pathways, particularly SIRT1/TPH2 signaling, drive these deficits or whether dietary phytochemicals like resveratrol can mitigate them. PURPOSE: To determine (1) the role of SIRT1/TPH2 signaling in IR-induced neurodevelopmental and psychiatric impairments, and (2) the therapeutic potential of maternal resveratrol supplementation to counteract these effects-a strategy not previously explored in prenatal radiation models. STUDY DESIGN: Mouse cohorts received prenatal X-ray irradiation (0, 1.0 Gy, 2 Gy gestational day 8) with/without resveratrol supplementation, followed by longitudinal cortical and behavioral analyses. METHODS: RNA sequencing/Western blotting quantified SIRT1, TPH2, BDNF, and senescence markers (P16, P21 and SA-β-gal). 5-HT levels were assessed by ELISA. Depression-like behaviors were tested via forced swim and tail suspension. RESULTS: IR-exposed fetuses exhibited progressive microcephaly with reduced cortical thickness, accompanied by SIRT1 downregulation, BDNF suppression, and elevated cellular senescence. Adult offspring displayed depression-like behaviors, linked to TPH2 downregulation and diminished 5-HT levels. Resveratrol supplementation normalized SIRT1/TPH2 signaling, restored cortical neurotrophic factors, and attenuated both microcephaly and depressive phenotypes. CONCLUSION: This study provides the first evidence that (1) SIRT1/TPH2 signaling is a central mediator of IR-induced neurodevelopmental and psychiatric impairments, and (2) maternal resveratrol supplementation prevents cortical damage and depression in offspring by rescuing this pathway. These findings position resveratrol as a novel, mechanism-driven intervention for fetal neuroprotection against environmental radiation.