BackgroundStrategies to maintain BBB integrity in diseases with a hypoxia/reoxygenation (H/R) component involve preventing glutathione (GSH) loss from endothelial cells. GSH efflux transporters include multidrug resistance proteins (Mrps). Therefore, characterization of Mrp regulation at the BBB during H/R is required to advance these transporters as therapeutic targets. Our goal was to investigate, in vivo, regulation of Abcc1, Abcc2, and Abcc4 mRNA expression (i.e., genes encoding Mrp isoforms that transport GSH) by nuclear factor E2-related factor (Nrf2) using a well-established H/R model.MethodsFemale Sprague–Dawley rats (200–250 g) were subjected to normoxia (Nx, 21% O2, 60 min), hypoxia (Hx, 6% O2, 60 min) or H/R (6% O2, 60 min followed by 21% O2, 10 min, 30 min, or 1 h) or were treated with the Nrf2 activator sulforaphane (25 mg/kg, i.p.) for 3 h. Abcc mRNA expression in brain microvessels was determined using quantitative real-time PCR. Nrf2 signaling activation was examined using an electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) respectively. Data were expressed as mean ± SD and analyzed via ANOVA followed by the post hoc Bonferroni t test.ResultsWe observed increased microvascular expression of Abcc1, Abcc2, and Abcc4 mRNA following H/R treatment with reoxygenation times of 10 min, 30 min, and 1 h and in animals treated with sulforaphane. Using a biotinylated Nrf2 probe, we observed an upward band shift in brain microvessels isolated from H/R animals or animals administered sulforaphane. ChIP studies showed increased Nrf2 binding to antioxidant response elements on Abcc1, Abcc2, and Abcc4 promoters following H/R or sulforaphane treatment, suggesting a role for Nrf2 signaling in Abcc gene regulation.ConclusionsOur data show increased Abcc1, Abcc2, and Abcc4 mRNA expression at the BBB in response to H/R stress and that Abcc gene expression is regulated by Nrf2 signaling. Since these Mrp isoforms transport GSH, these results may point to endogenous transporters that can be targeted for BBB protection during H/R stress. Experiments are ongoing to examine functional implications of Nrf2-mediated increases in Abcc transcript expression. Such studies will determine utility of targeting Mrp isoforms for BBB protection in diseases with an H/R component.

AbstractBackground:Cardiac catheterisations for CHD produce anxiety for patients and families. Current strategies to mitigate anxiety and explain complex anatomy include pre-procedure meetings and educational tools (cardiac diagrams, echocardiograms, imaging, and angiography). More recently, three-dimensionally printed patient-specific models can be added to the armamentarium. The purpose of this study was to evaluate the efficacy of pre-procedure meetings and of different educational tools to reduce patient and parent anxiety before a catheterisation.Methods:Prospective study of patients ≥18 and parents of patients <18 scheduled for clinically indicated catheterisations. Patients completed online surveys before and after meeting with the interventional cardiologist, who was blinded to study participation. Both the pre- and post-meeting surveys measured anxiety using the State-Trait Anxiety Inventory. In addition, the post-meeting survey evaluated the subjective value (from 1 to 4) of individual educational tools: physician discussion, cardiac diagrams, echocardiograms, prior imaging, angiograms and three-dimensionally printed cardiac models. Data were compared using paired t-tests.Results:Twenty-three patients consented to participate, 16 had complete data for evaluation. Mean State-Trait Anxiety Inventory scores were abnormally elevated at baseline and decreased into the normal range after the pre-procedure meeting (39.8 versus 31, p = 0.008). Physician discussion, angiograms, and three-dimensional models were reported to be most effective at increasing understanding and reducing anxiety.Conclusion:In this pilot study, we have found that pre-catheterisation meetings produce a measurable decrease in patient and family anxiety before a procedure. Discussions of the procedure, angiograms, and three-dimensionally printed cardiac models were the most effective educational tools.