Barton S.K.,The Ritchie Center Hudson Institute of Medical Research Clayton 3168Victoria Australia |
Mcdougall A.R.A.,Monash University |
Melville J.M.,The Ritchie Center Hudson Institute of Medical Research Clayton 3168Victoria Australia |
Moss T.J.M.,Monash University |
And 5 more authors.
Journal of Physiology | Year: 2015
Key points: Erythropoietin is a neuroprotectant undergoing clinical trial for brain injury in term and preterm infants. This is the first experimental study to assess the acute effects of erythropoietin on the cerebral white matter in preterm ventilated lambs. Administration of erythropoietin within minutes of injurious ventilation onset amplified pro-inflammatory cytokine gene expression in both the periventricular and subcortical white matter compared to the ventilation alone group; erythropoietin had no effect on the area of microglial aggregations in white matter regions with a reduction in cellular density of aggregations in the subcortical white matter only. Administration of erythropoietin in conjunction with injurious ventilation increased gene expression of tight junction proteins and reduced protein extravasation from blood vessels in the cerebral white matter. Given the increase in inflammation after erythropoietin, we recommend further investigation into its use as a treatment for ventilated preterm babies prior to clinical translation. Inadvertently injurious ventilation of preterm neonates in the delivery room can cause cerebral white matter (WM) inflammation and injury. We investigated the impact of an early high dose of recombinant human erythropoietin (EPO) on ventilation-induced WM changes in preterm lambs. Injurious ventilation, targeting a VT of 15 ml kg-1 with no positive end-expiratory pressure, was initiated for 15 min in preterm lambs (0.85 gestation). Conventional ventilation was continued for a further 105 min. Lambs received either 5000 IU kg-1 of EPO (EPREX®; Vent+EPO; n = 6) or vehicle (Vent; n = 8) via an umbilical vein at 4 ± 2 min. Markers of WM injury and inflammation were assessed using quantitative real-time PCR (qPCR) and immunohistochemistry and compared to a group of unventilated controls (UVC; n = 4). In Vent+EPO lambs compared to Vent lambs: (i) interleukin (IL)-1β and IL-6 mRNA levels in the periventricular WM and IL-8 mRNA levels in the subcortical WM were higher (P < 0.05 for all); (ii) the density of microglia within the aggregations was not different in the periventricular WM and was lower in the subcortical WM (P = 0.001); (iii) the density of astrocytes was lower in the subcortical WM (P = 0.002); (iv) occludin and claudin-1 mRNA levels were higher in the periventricular WM (P < 0.02 for all) and (vi) the number of blood vessels with protein extravasation was lower (P < 0.05). Recombinant human EPO had variable regional effects within the WM when administered during injurious ventilation. The adverse short-term outcomes discourage the use of early high dose EPO administration in preterm ventilated babies. © 2015 The Physiological Society.