Restraint stress alters pro-inflammatory cytokine expression and increases superoxide dismutase in the rat hypothalamus and hippocampus
The impact of restraint stress on changes in cytokine expression and oxidative stress markers in hippocampal (Hipp) and hypothalamic (Hyp) regions of the brain, were assessed in a rat model. In addition, immune and inflammatory variables were assessed in peripheral blood. Male Wistar rats were acutely (30 min) or repeatedly (30 min/d for 14 consecutive days) exposed to a restraint stress, or maintained as non-stressed controls. At the time of sacrifice, whole blood and brain tissues enriched in Hyp or Hipp regions were collected; blood was collected with EDTA as an anticoagulant and centrifuged to yield plasma. All tissue samples were frozen at -20°C until assayed. Plasma samples were evaluated for pro-inflammatory cytokine expression (TNFα, IL-6, IL-1α, IL-1β) by ELISA to confirm findings previously seen by Milliplex® analysis in separate groups of a different strain of rats. Hipp and Hyp isolates were homogenized and subjected to the same cytokine analysis, and were Western blotted to determine expression levels of oxidative stress markers superoxide dismutase 1 (SOD1) and the receptor for advanced glycation end-products (RAGE) and insulin degrading enzyme (IDE). Repeated stress increased the expression of SOD1, and acute and repeated stress decreased levels of IL-1α but increased levels of IL-1β. TNFα and IL-6 levels remained unchanged regardless of stressor. No other significant differences were seen. This study provides valuable insight on how stress exposure can alter important homeostatic functions, and informs possible pathways through which repeated or chronic stress may affect the incidence or progression of diseases that include inflammatory or oxidative stress components.
Barron, Kristina Isabel, "Restraint stress alters pro-inflammatory cytokine expression and increases superoxide dismutase in the rat hypothalamus and hippocampus" (2015). ETD Collection for University of Texas, El Paso. AAI1600303.