Erythropoietin prevents LPS-induced preterm birth and increases offspring survival.

PROBLEM: Preterm delivery is the leading cause of neonatal mortality and contributes to delayed physical and cognitive development in children. At present, there is no efficient therapy to prevent preterm labor. A large body of evidence suggests that infections might play a significant and potentially preventable cause of premature birth. This work assessed the effects of erythropoietin (EPO) in a murine model of inflammation-associated preterm delivery, which mimics central features of preterm infections in humans. METHOD OF STUDY: BALB/c mice were injected i.p. with 20 000 IU/kg EPO or normal saline twice on gestational day (GD) 15, with a 3 hours time interval between injections. An hour after the first EPO or normal saline injection, all mice received two injections of 50 µg/kg LPS, also given 3 hours apart. RESULTS: EPO significantly prevented preterm labor and increased offspring survival in an LPS induced preterm delivery model. EPO prevented LPS-induced leukocyte infiltration into the placenta. Moreover, EPO inhibited the expression of pro-inflammatory cytokines, interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumour necrosis factor-α (TNF-α) in maternal serum and amniotic fluid. EPO also prevented LPS-induced increase in placental prostaglandin (PG)E2 and uterine inducible nitric oxide synthase (iNOS) production, while decreasing nuclear factor kappa-B (NF-κß) activity in the myometrium. EPO also increased the gene expression of placental programmed cell death ligand 1 (PD-L1) in LPS-treated mice. CONCLUSIONS: Our results suggest that EPO could be a potential novel therapeutic strategy to tackle infection-related preterm labor.

Postconditioning with repeated mild hypoxia protects neonatal hypoxia-ischemic rats against brain damage and promotes rehabilitation of brain function.

RATIONALE: Mild hypoxia conditioning induced by repeated episodes of transient ischemia is a clinically applicable method for protecting the brain against injury after hypoxia-ischemic brain damage. OBJECTIVE: To assess the effect of repeated mild hypoxia postconditioning on brain damage and long-term neural functional recovery after hypoxia-ischemic brain damage. METHODS AND RESULTS: Rats received different protocols of repeated mild hypoxia postconditioning. Seven-day-old rats with hypoxia ischemic brain damage (HIBD) from the left carotid ligation procedure plus 2 h hypoxic stress (8% O2 at 37 °C) were further receiving repeated mild hypoxia intermittently. The gross anatomy, functional analyses, hypoxia inducible factor 1 alpha (HIF-1a) expression, and neuronal apoptosis of the rat brains were subsequently examined. Compared to the HIBD group, rats postconditioned with mild hypoxia had elevated HIF-1a expression, more Nissl-stain positive cells in their brain tissue and their brains functioned better in behavioral analyses. The recovery of the brain function may be directly linked to the inhibitory effect of HIF-1α on neuronal apoptosis. Furthermore, there were significantly less neuronal apoptosis in the hippocampal CA1 region of the rats postconditioned with mild hypoxia, which might also be related to the higher HIF-1a expression and better brain performance. Overall, these results suggested that postconditioning of neonatal rats after HIBD with mild hypoxia increased HIF-1a expression, exerted a neuroprotective effect and promoted neural functional recovery. CONCLUSIONS: Repeated mild hypoxia postconditioning protects neonatal rats with HIBD against brain damage and improves neural functional recovery. Our results may have clinical implications for treating infants with HIBD.