Granulocyte colony-stimulating factor significantly decreases density of hippocampal caspase 3-positive nuclei, thus ameliorating apoptosis-mediated damage, in a model of ischaemic neonatal brain injury.
DOI: 10.1093/icvts/ivx047; PMCID: PMC5886347
OBJECTIVES: Ischaemic brain injury is a major complication in patients undergoing surgery for congenital heart disease, with the hippocampus being a particularly vulnerable region. We hypothesized that neuronal injury resulting from cardiopulmonary bypass and associated circulatory arrest is ameliorated by pretreatment with granulocyte colony-stimulating factor (G-CSF), a cytokine and an anti-apoptotic neurotrophic factor.
METHODS: In a model of ischaemic brain injury, 4 male newborn piglets were anaesthetized and subjected to deep hypothermic circulatory arrest (DHCA) (cooled to 18°C, DHCA maintained for 60 min, rewarmed and recovered for 8-9 h), while 4 animals received G-CSF (34 µg/kg, intravenously) 2 h prior to the DHCA procedure. At the end of each experiment, the animals were perfused with a fixative, the hippocampus was extracted, cryoprotected, cut and the brain sections were immunoprocessed for activated caspase 3, a pro-apoptotic factor. Immunopositive neuronal nuclei were counted in multiple counting boxes (440 × 330 µm) centred on the CA1 or CA3 hippocampal regions and their mean numbers compared between the different treatment groups and regions.
RESULTS: G-CSF pretreatment resulted in significantly lower counts of caspase 3-positive nuclei per counting box in both the CA1 [52.2 ± 9.3 (SD) vs 61.6 ± 8.4, P < 0.001] and CA3 (41.2 ± 6.9 vs 60.4 ± 16.4, P < 0.00002) regions of the hippocampus as compared to DHCA groups. The effects of G-CSF were significant for pyramidal cells of both regions and for interneurons in the CA3 region.
CONCLUSIONS: In an animal model of ischaemic brain injury, G-CSF reduces neuronal injury in the hippocampus, thus potentially having beneficial effect on neurologic outcomes.
Interact Cardiovasc Thorac Surg
Animals; Animals, Newborn; Apoptosis; Brain Ischemia; Cardiopulmonary Bypass; Caspase 3; Cell Count; Circulatory Arrest, Deep Hypothermia Induced; Disease Models, Animal; Granulocyte Colony-Stimulating Factor; Hippocampus; Immunohistochemistry; Injections, Intravenous; Male; Swine
Apoptosis; Cardiac surgery; Caspase 3; Congenital heart disease; Developing brain; Hippocampus
Pastuszko, P., Schears, G. J., Kubin, J., Wilson, D. F., Pastuszko, A. Granulocyte colony-stimulating factor significantly decreases density of hippocampal caspase 3-positive nuclei, thus ameliorating apoptosis-mediated damage, in a model of ischaemic neonatal brain injury. Interact Cardiovasc Thorac Surg 25, 600-605 (2017).