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Melatonin modulates neonatal brain inflammation through endoplasmic reticulum stress, autophagy, and mi R ‐34a/silent information regulator 1 pathway
Author(s) -
Carloni Silvia,
Favrais Géraldine,
Saliba Elie,
Albertini Maria Cristina,
Chalon Sylvie,
Longini Mariangela,
Gressens Pierre,
Buonocore Giuseppe,
Balduini Walter
Publication year - 2016
Publication title -
journal of pineal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 131
eISSN - 1600-079X
pISSN - 0742-3098
DOI - 10.1111/jpi.12354
Subject(s) - endoplasmic reticulum , regulator , inflammation , autophagy , melatonin , unfolded protein response , medicine , endocrinology , chemistry , biology , microbiology and biotechnology , apoptosis , biochemistry , gene
Maternal infection/inflammation represents one of the most important factors involved in the etiology of brain injury in newborns. We investigated the modulating effect of prenatal melatonin on the neonatal brain inflammation process resulting from maternal intraperitoneal (i.p.) lipopolysaccharide ( LPS ) injections. LPS (300 μg/kg) was administered to pregnant rats at gestational days 19 and 20. Melatonin (5 mg/kg) was administered i.p. at the same time as LPS . Melatonin counteracted the LPS sensitization to a second ibotenate‐induced excitotoxic insult performed on postnatal day ( PND ) 4. As melatonin succeeded in reducing microglial activation in neonatal brain at PND 1, pathways previously implicated in brain inflammation regulation, such as endoplasmic reticulum ( ER ) stress, autophagy and silent information regulator 1 ( SIRT 1), a melatonin target, were assessed at the same time‐point in our experimental groups. Results showed that maternal LPS administrations resulted in an increase in CHOP and Hsp70 protein expression and eIF 2α phosphorylation, indicative of activation of the unfolded protein response consequent to ER stress, and a slighter decrease in the autophagy process, determined by reduced lipidated LC 3 and increased p62 expression. LPS ‐induced inflammation also reduced brain SIRT 1 expression and affected the expression of miR‐34a, miR146a, and miR‐126. All these effects were blocked by melatonin. Cleaved‐caspase‐3 apoptosis pathway did not seem to be implicated in the noxious effect of LPS on the PND 1 brain. We conclude that melatonin is effective in reducing maternal LPS ‐induced neonatal inflammation and related brain injury. Its role as a prophylactic/therapeutic drug deserves to be investigated by clinical studies.