The protective effects of Ferrostatin-1 against inflammation-induced preterm birth and fetal brain injury

INTRODUCTION

Recent studies have suggested the involvement of ferroptosis in preterm birth. Despite compelling evidence, the underlying mechanism remains unknown. This investigation aimed to determine the therapeutic effects of Ferrostatin-1 (Fer-1), an inhibitor of ferroptosis, in preterm birth and fetal brain injury.

METHODS

Human placenta samples and clinical data of participants were collected to ascertain whether placental ferroptosis was associated with preterm birth. Lipopolysaccharide (LPS)-induced preterm birth mouse model was used to examine the protective effects of Fer-1 on preterm birth. Fetal brain tissues and offspring mice at 5 and 8 weeks were studied to determine the effects of Fer-1 on the cognitive function of offspring.

RESULTS

We examined the mechanism of spontaneous preterm birth and discovered that placental ferroptosis was associated with preterm birth. Fer-1 inhibited preterm birth by ameliorating placental ferroptosis and maternal inflammation, thus improving LPS-induced intrauterine inflammation to maintain pregnancy. Antenatal administration of Fer-1 prevented LPS-induced fetal brain damage in the acute phase and improved long-term neurodevelopmental impairments by improving placental neuroendocrine signaling and maintaining placental function.

CONCLUSION

Fer-1 inhibited preterm birth and fetal brain injury by inhibiting maternal inflammation and improving placental function. Our findings provide a novel therapeutic strategy for preterm birth.

Maternal Progesterone Treatment Reduces Maternal Inflammation-Induced Fetal Brain Injury in a Mouse Model of Preterm Birth

Maternal natural vaginal progesterone (nVP) administration has been shown to reduce the risk of preterm birth (PTB). The largest randomized trial of nVP for PTB (OPPTIMUM) noted a sonographic reduction in neonatal brain injury following nVP treatment. We investigated the neuroinflammatory protective effect of maternal nVP in a mouse model for maternal inflammation. Pregnant mice (n = 24) were randomized to nVP (1 mg/day) or vehicle from days 13-16 of gestation. At days 15 and 16, lipopolysaccharide (30 μg) or saline were administered. Mice were sacrificed 4 h following the last injection. Fetal brains and placentas were collected. Levels of NF-κB, nNOS, IL-6, and TNFα were determined by Western blot. Maternal lipopolysaccharide significantly increased fetal brain levels of IL-6 (0.33 ± 0.02 vs. 0.11 ± 0.01 u), TNFα (0.3 ± 0.02 vs. 0.10 ± 0.01 u), NF-κB (0.32 ± 0.01 vs. 0.17 ± 0.01 u), and nNOS (0.24 ± 0.04 vs. 0.08 ± 0.01 u), and reduced the total glutathione levels (0.014 ± 0.001 vs. 0.026 ± 0.001 pmol/μl; p < 0.01) compared with control. Maternal nVP significantly reduced fetal brain levels of IL-6 (0.14 ± 0.01 vs. 0.33 ± 0.02 u), TNFα (0.2 ± 0.06 vs. 0.3 ± 0.02 u), NF-κB (0.16 ± 0.01 vs 0.32 ± 0.01 u), and nNOS (0.14 ± 0.01 vs 0.24 ± 0.04 u), and prevented the reduction of fetal brain total glutathione levels (0.022 ± 0.001 vs. 0.014 ± 0.001 pmol/μl; p < 0.01) to levels similar to controls. A similar pattern was demonstrated in the placenta. Maternal nVP for PTB may protect the fetal brain from inflammation-induced brain injury by inhibiting specific inflammatory and oxidative pathways in both brain and placenta.

Protective effects of quercetin against brain injury in a rat model of lipopolysaccharide-induced fetal brain injury

Maternal exposure to lipopolysaccharide (LPS), a bacterial endotoxin produced during infection, leads to disruption in fetal brain development and causes newborn brain injury. Quercetin (QR) is a multipotent flavonoid that functions as an antioxidant and protects against inflammation and neurodegeneration. In this study, we explored the potential functions of QR in alleviating maternal LPS exposure induced fetal brain damage. Pregnant rats at late gestational stages were treated with saline, LPS, QR, LPS and QR. Brain injury biomarker TGF-1β was assessed in cerebrospinal fluid (CSF) and brain tissue of newborn rats. Pro-inflammatory cytokines, apoptosis markers and oxidative stress indicators were evaluated. We found that LPS treatment induced an increased production of TGF-1β which was suppressed by QR administration. LPS enhanced pro-apoptotic Bax and inhibited anti-apoptotic Bcl-2 expression. QR reduced that ratio of Bax and Bcl-2 that was high in LPS treated brain tissue. Additionally, QR suppressed oxidative stress induced by LPS. Finally, QR reduced the levels of pro-inflammatory cytokines that were produced as a result of LPS exposure. In summary, our study indicates that QR potently alleviates maternal LPS exposure induced fetal brain injury in rats, making it a potential therapeutic for suppressing infant brain damage as a result of maternal infection.

Preventing childhood and lifelong disability: Maternal dietary supplementation for perinatal brain injury

The majority of brain injuries that lead to cerebral palsy, developmental disability, and mental health disorders have their onset in utero. These lifelong conditions come with great economic and emotional burden as they impact function in nearly all domains of affected individuals' lives. Unfortunately, current therapeutic options are limited. There remains a focus on rescue, rehabilitation, and regeneration after the injury has occurred, rather than aiming to prevent the initial injury. Prevention would imply treating the mother during pregnancy to alter the fetal environment and in turn, treat the fetus. Fear of harming the developing fetus remains as a result of errors of the past such as the release of thalidomide. In this review, we outline evidence from animal studies and clinical trials that have explored maternal dietary supplementation with natural health products (including nutraceuticals and functional foods) for perinatal brain injury prevention. Namely, we discuss magnesium sulphate, creatine, choline, melatonin, resveratrol and broccoli sprouts/sulforaphane. Although clinical trials have only been completed in this realm for magnesium sulphate, results in animal models have been promising, suggesting that this is a productive avenue for further research. Natural health products may provide safe, effective, affordable, and easily accessible prevention of fetal brain injury and resulting lifelong disabilities.

Intrauterine inflammation reduces postnatal neurogenesis in the hippocampal subgranular zone and leads to accumulation of hilar ectopic granule cells

Prenatal inflammation is associated with poor neurobehavioral outcomes in exposed offspring. A common route of exposure for the fetus is intrauterine infection, which is often associated with preterm birth. Hippocampal development may be particularly vulnerable to an inflammatory insult during pregnancy as this region remains highly neurogenic both prenatally and postnatally. These studies sought to determine if intrauterine inflammation specifically altered hippocampal neurogenesis and migration of newly produced granule neurons during the early postnatal period. Microglial and astroglial cell populations known to play a role in the regulation of postnatal neurogenesis were also examined. We show that intrauterine inflammation significantly reduced hippocampal neurogenesis between postnatal days 7 (P7) and P14 as well as decreased granule cell density at P28. Ectopic migration of granule cells was observed in LPS-exposed mice at P14, but not at P28. Intrauterine inflammation had no effect on hippocampal astrocyte or microglia density or on apoptosis rate at the postnatal time points examined. Thus, exposure to intrauterine inflammation disrupts early postnatal neurogenesis and leads to aberrant migration of newly born granule cells.