The Role of Melatonin in Oxidative Stress, DNA Damage, Apoptosis and Angiogenesis in Fetal Eye under Preeclampsia and Melatonin Deficiency Stress.

ABSTRACT

Aim: The aim of this study was to investigate the possible mechanisms of ocular damage induced by pinealectomy (PNX) and preeclampsia (PE), and to determine the cellular and molecular effects of melatonin treatment on oxidative stress, DNA damage, molecular chaperone responses, induction of apoptosis and angiogenesis in the fetal eye of both PNX and PNX+PE animals. Material and Methods: We analysed therapeutic potential of melatonin on fetal eye damage in PNX and PNX+PE animals using Malondialdehyde (MDA), Random Amplified Polymorphic DNA (RAPD), qRT-PCR and Western blot assays. Results: Our study presents three preliminary findings: (a) in fetal eye tissues, PNX and PNX+PE significantly induce oxidative damage to both DNA and protein contents, leading to a dramatic increase in caspase-dependent apoptotic signalling in both mitochondrial and death receptor pathways; (b) the same conditions trigger hypoxia biomarkers in addition to significant overexpression of HIF1-α, HIF1-ß, MMP9 and VEGF genes in the fetal eye; (c) finally, melatonin regulates not only the expression of genes encoding antioxidant enzymes and increase in DNA damage as well as lipid peroxidation but also limits programmed cell death processes in the fetal eye of PNX and PNX+PE animals . Furthermore, melatonin can relatively modulate genes in the HIF1 family, TNF-α and VEGF, thus acting as a direct anti-angiogenic molecule. In conclusion, both PNX and PNX+PE induce ocular damage at both cellular and molecular levels in fetal eye tissue of rats. Conclusion: Our results clearly indicate the potential of melatonin as a preventative therapeutic intervention for fetal ocular damage triggered by both PNX and PNX+PE.