LE3 .A278 2018

2018

Wilson, Brian

Acadia University

Bachelor of Science

Honours

Biology

Biology

Stroke accounts for over six million deaths per year. The inflammatory response to ischemic stroke exacerbates brain damage, and the pro-inflammatory cytokine TNF-a is a mediator of cell death in the ischemic brain. The transcription factor HIF-1a can ameliorate ischemic injury by inducing the expression of cytoprotective genes. Relaxin peptides are known to exhibit neuroprotective effects and have been shown to reduce cell death in rat brain tissue under hypoxic conditions. We hypothesized that relaxins may reduce cell death in the ischemic brain by reducing expression of TNF-a and increasing expression of HIF-1a. Organotypic neonatal rat brain cultures were prepared and cultured for two weeks. Brain slices received one of five treatments: oxygenated balanced salt solution (normoxic control; NC), oxygen glucose deprived salt solution (OGD control), and OGD media with either H2 relaxin, H3 relaxin, or H3 relaxin and the H3 relaxin receptor (RXFP3) antagonist R3 B1-22R. Proteins were extracted from the brain tissue and western blots were performed to quantify the amount of β-actin, HIF1-a, and TNF-a in each brain slice. Mean blot volumes and densities for each group were compared using a one-way ANOVA and Tukey’s post-hoc test. HIF-1a was not detected in any protein samples. TNF-a was detected in all samples at 26 kDa, and was likely glycosylated. Density and volume analyses revealed that the H3 relaxin with R3 B1-22R group contained significantly more TNF-a than other treatment groups. Blot volume, but not density showed that the H3 relaxin group contained significantly more TNF-a than the control groups or the H2 relaxin group. Further research is needed to determine the time course of pro-inflammatory cytokine expression in organotypic culture and to further understand the role of TNF-a in the ischemic brain.

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https://scholar.acadiau.ca/islandora/object/theses:2677