Oxidative stress and apoptosis of the spinal cord in a rat model of retinoic acid-induced neural tube defects

Neural tube defects (NTDs) are severe congenital anomalies that significantly impact the central nervous system, arising from the neural tube's failure to close during early embryogenesis. In this study, we investigated NTDs and associated pathophysiological mechanisms in foetal rats following exposure to all-trans retinoic acid (atRA). Out of 168 embryos from 15 pregnant rats in the experimental group, 78% displayed NTDs with notable spinal deformities, primarily in the lumbar-sacral region, similar to human cases. Body weight and crown-rump length (CRL) measurements indicated significant growth impairment in the NTD group compared to controls, while the atRA-treated group without NTDs showed no notable differences in growth. Immunohistochemistry (IHC) results demonstrated decreased NeuN and PCNA expression in the NTD group's spinal cord. Oxidative stress markers showed markedly reduced superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) activity, alongside increased malondialdehyde (MDA) levels in the NTD group, indicating heightened oxidative stress. Analysis of apoptosis-related proteins revealed elevated Bax and caspase-3 levels, reduced Bcl-2 and lower poly (ADP-ribose) polymerase (PARP) in the NTD group, suggesting a pronounced shift towards proapoptotic pathways, potentially contributing to NTD progression. Our findings indicate that oxidative stress and apoptosis play significant roles in the development of NTDs. Future investigations should aim to pinpoint critical regulatory genes or proteins that might be targeted for therapeutic interventions to alleviate oxidative stress and apoptosis in NTD development.