Prematurity, observed in 15 million births worldwide each year, is a clinical condition that is a major cause of neonatal mortality and morbidity in the short and long term. Preterm infants are at high risk of developing respiratory problems, sepsis, and other morbidities leading to neurodevelopmental impairment and neurobehavioral disorders. Perinatal glucocorticosteroids have been widely used for the prevention and treatment of adverse outcomes linked to prematurity. However, despite their short-term benefits due to their maturational properties, some clinical trials have shown an association between steroids exposure and abnormal brain development in infants born preterm. Neuroinflammation has emerged as a preeminent factor for brain injury in preterm infants, and the major role of microglia, the brain resident immune cells, has been recently highlighted. Considering the role of microglia in the modulation of brain development, the aim of this review is to summarize the effects of endogenous and exogenous glucocorticosteroids on brain development and discuss the possible role of microglia as the mediator of these effects.

Cerebral stroke, traumatic brain injury, and hypoxic ischemic encephalopathy are among the most frequently occurring brain injuries. A complex pathogenesis, characterized by a synergistic interaction between alterations of the cerebrovascular system, cell death, and inflammation, is at the basis of the brain damage that leads to behavioral and neurodevelopmental disabilities in affected subjects. Sildenafil is a selective inhibitor of the enzyme phosphodiesterase 5 (PDE5) that is able to cross the blood–brain barrier. Preclinical data suggest that sildenafil may be a good candidate for the prevention or repair of brain injury in both adults and neonates. The aim of this review is to summarize the evidence supporting the neuroprotective action of sildenafil and discuss the possible benefits of the association of sildenafil with current therapeutic strategies.

Microglial activation is a key modulator of brain vulnerability in response to intra-uterine growth restriction (IUGR). However, the consequences of IUGR on microglial development and the microglial proteome are still unknown. We used a model of IUGR induced by a gestational low-protein diet (LPD) in rats. Microglia, isolated from control and growth-restricted animals at P1 and P4, showed significant changes in the proteome between the two groups. The expression of protein sets associated with fetal growth, inflammation, and the immune response were significantly enriched in LPD microglia at P1 and P4. Interestingly, upregulation of protein sets associated with the oxidative stress response and reactive oxygen species production was observed at P4 but not P1. During development, inflammation-associated proteins were upregulated between P1 and P4 in both control and LPD microglia. By contrast, proteins associated with DNA repair and senescence pathways were upregulated in only LPD microglia. Similarly, protein sets involved in protein retrograde transport were significantly downregulated in only LPD microglia. Overall, these data demonstrate significant and multiple effects of LPD-induced IUGR on the developmental program of microglial cells, leading to an abnormal proteome within the first postnatal days.