Progression of vascular function and blood pressure in a mouse model of Kawasaki disease

Abstract

Background: Kawasaki disease (KD) is a systemic vasculitis of childhood characterized by vascular damage in the acute stage, which can persist into the late stage. Aneurysms, myocardial infarction, and death are long-standing complications associated with KD. The vascular mechanisms in the cardiovascular risk of KD are not fully studied. Herein, we investigated the vascular function and blood pressure regulation in a murine model of KD. Material and methods: We used the Candida albicans water soluble (CAWS) fraction model. Mice were injected with 4 mg CAWS for five consecutive days and separated into 3 groups. Control (Ctrl): water injected for 5 days; CAWS 7 days (C7): CAWS injected for 5 days plus 2 additional days of wait; CAWS 28 days (C28): CAWS injected for 5 days plus 23 additional days of wait. Blood pressure was analyzed via radiotelemetry. In the end, the heart and arteries were harvested for vasculitis characterization and vascular function in a wire myograph. Rat Aortic Vascular Smooth Muscle cells (RASMC) were used to dissect the molecular mechanisms in vitro. Main findings: C7 presented elevated inflammatory markers in the coronary area (CA) and abdominal aortae (AA), whereas C28 showed severe vasculitis in CA and AA. No difference was found in blood pressure and heart rate. Vascular dysfunction characterized by higher contractility to norepinephrine (NA) in C7 and C28 was abolished by blocking nitric oxide (NO) production, reactive oxygen species (ROS), and cyclooxygenase (COX)-derived products. RASMC treated with CAWS (10ug/mL) presented an increase in COX2 expression, which was prevented by pre-treating the cells with TAK-242 [Toll like receptor 4 (TLR4) antagonist, 3x10-5M]. Conclusion: Our data indicate that the murine model of KD is associated with vascular dysfunction likely dependent on COX-derived products, oxidant properties, and NO bioavailability. Furthermore, VSMC may present an important role in the genesis of vascular dysfunction and vasculitis via the TLR4 pathway. Finally, the CAWS model seems not to be appropriate to study KD-associated shock. More studies are necessary to understand whether vascular dysfunction and COXs are triggers for vasculitis.