Proceedings of The Physiological Society

Physiology 2016 (Dublin, Ireland) (2016) Proc Physiol Soc 37, PCA077

Poster Communications

Potential therapeutic role for erythropoietin mimetic, ARA 290, in a mouse model of emphysema

S. Whelan1, K. Rochfort1, E. Coleman1, P. McLoughlin1, K. Howell1

1. School of Medicine and Medical Science, University College Dublin, Dublin, Dublin, Ireland.

Chronic lung diseases, including emphysema, are a leading cause of death worldwide. The pathogenesis of emphysema is extensively debated; however recent research indicates that vascular loss may play a key initiating role. Inhibition of vascular endothelial growth factor receptors lead to emphysematous changes in the adult rat lung (1), whilst co-administration of erythropoietin (EPO) prevented similar disease development in a neonatal mouse model (2). EPO administration may deleteriously augment haematocrit, therefore, a non-haematopoietic-EPO mimetic, ARA 290 (ARAIM Pharmaceuticals) has been developed which specifically activates the EPO tissue-protective signalling pathway via activation of the innate repair receptor (EPOR/βCR). We hypothesised that ARA 290 would attenuate disease development in a mouse model of emphysema, potentially by preventing the loss of vasculature or maintaining normal vascular integrity. Adult male C57BL/6 mice (n=7-10 per group) were randomly assigned to one of 4 experimental groups: 1) Control (no treatment), (2) Emphysema (porcine pancreatic elastase (PPE); 1 unit via oropharyngeal aspiration), (3) Emphysema + ARA 290 (PPE + 30µg/kg ARA 290 via intraperitoneal injection), (4) ARA 290 treatment alone. After 4 weeks, mice were anaesthetised by intraperitoneal injection of sodium pentobarbitone (60mg/Kg) and euthanized by exsanguination. Haemodynamic evaluation of pulmonary vascular resistance (PVR) was carried out using isolated perfused lung techniques. Lung tissue was fixed at standard pressures (25cm H2O) and wax embedded in an isotropic uniform random orientation. Tissue sections (3μm) were subsequently stained with either haematoxylin and eosin for stereological evaluation of structural alterations in alveolar wall, or aquaporin-1 for evaluation of structural changes in the pulmonary vasculature. PPE-induced emphysematous mice had significantly increased PVR, indicative of pulmonary hypertension, which was partially ameliorated with ARA 290 treatment. Emphysematous mice had significantly reduced total alveolar wall volume per right lung; the loss of alveolar wall was prevented by ARA 290. ARA 290 did not affect intra-acinar blood vessel length, volume or wall thickness, suggesting that ARA 290 is potentially mediating the protective effects via preventing the loss of alveolar capillaries.Values are expressed as mean ± S.E.M, compared by ANOVA with Bonferroni Post-Hoc analysis. * indicates significant difference from all groups (p<0.05). Data generated to date suggests a potential therapeutic role for ARA 290 in this setting of emphysema, however further work is warranted.

Where applicable, experiments conform with Society ethical requirements