bioRxiv Science⌕ Search

bioRxiv · 10.1101/2022.08.25.505303

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

Abstract

BackgroundKawasaki 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 methodsWe 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 findingsC7 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]. ConclusionOur 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.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Delvecchio, M., Alves, J. V., Saiyid, A. Z., Singh, S., Galley, J. C., Awata, W. M. C., Bruder-Nascimento, A., Bruder-Nascimento, T.. 2022-08-26. Progression of vascular function and blood pressure in a mouse model of Kawasaki disease. https://doi.org/10.1101/2022.08.25.505303

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Denaturation-sensitive BRET probes enable intracellular thermal shift measurements across diverse protein targets and biomolecular complexes

Thermal shift assays have revolutionized drug discovery, but can be limited in sensitivity and scalability. Combining the unique attributes of differential scanning fluorimetry (DSF) and cellular thermal shift (CETSA), we report the methodological framework for the bioluminescence resonance energy transfer shift assay (BRETSA). BRETSA utilizes denaturation sensitive BRET probes, in combination with luciferase-tagged target proteins, to track and longitudinally record thermal shift in living cells. Denaturation profiles were successfully measured for over 500 globular proteins, spanning 24 target families in diverse cellular compartments. Among these, target engagement was confirmed for over 200 proteins; including validated drug targets as well as understudied members of the kinase subfamily. Leveraging orthosteric, allosteric, and covalent ligands in potency studies, this method offers improved sensitivity and scalability compared to other thermal shift methods. We extend the utility of BRETSA to interrogate target engagement at biomolecular complexes and query cooperative binding for molecular glues and emerging tricomplex drug modalities.

pharmacology and toxicology↗

Peptide Sequence Determines the Efficacy of Single-Dose AAV-Vectorized GLP-1R Agonists in Diet-Induced Obese Mice

Background: Glucagon-like peptide-1 receptor (GLP-1R) agonists such as semaglutide produce substantial weight loss and glycemic improvement, but their long-term efficacy depends on sustained adherence to chronic dosing. Adeno-associated virus (AAV) gene therapy could, in principle, provide durable GLP-1R agonist (GLP-1RA) exposure from a single administration, but the degree of peptide engineering required for a vectorized GLP-1RA transgene to be efficacious in vivo is unknown. Methods: We generated four self-complementary AAV (scAAV) constructs encoding: native human GLP-1(7-36) (GLP-1), a DPP-IV-resistant Gly8-GLP-1(7-36) variant (Gly8), Exendin-4 (Ex4), or an Exendin-4 human IgG4 Fc fusion protein (Ex4-Fc). All four constructs were validated to secrete functional GLP-1R agonists in vitro using a conditioned-media potency assay. Subsequently, these constructs were packaged into PHP.eB capsids and administered as a single intravenous dose (5x1012 vg/kg) to diet-induced obese (DIO) mice alongside a vehicle control. Body weight, body composition, food intake, fasting plasma insulin, and oral glucose tolerance were assessed over a 3-week period. At the end of the study, tissues were harvested for assessments of plasma/liver lipids, tissue transgene transcript and peptide levels. Results: HEK293 cells transfected with the four AAV constructs all secreted active peptides/proteins as assessed by a cell-based GLP-1R activation assay, although the effective concentration of the GLP-1 constructs in the media spanned nearly four orders of magnitude 72 hours after transfection. In diet-induced obese (DIO) mice, Ex4 and Ex4-Fc vectors, but not GLP-1 or Gly8 vectors, produced significant reductions in body weight of up to 22.6% of starting body weight out to 21 days after a single dose. In addition, reductions in food intake, fat mass, and fasting insulin relative to vehicle were also observed for Ex4 and Ex4-Fc. Furthermore, Ex4-Fc improved oral glucose tolerance while reducing plasma cholesterol and liver triglycerides relative to vehicle. Although transcript levels did not differ appreciably among the four constructs in either brain or liver, measurable peptide product in plasma and brain lysate tracked the rank order of the in vitro supernatant screen, with GLP-1 and Gly8 groups indistinguishable from endogenous background. Conclusions: PHP.eB scAAV Ex4 and Ex4-Fc showed robust efficacy on multiple metabolic endpoints including weight loss and glucose tolerance. In contrast, vectorized GLP-1 and Gly8 showed no in vivo efficacy despite comparable levels of viral transcript in the brain and the liver. Vectorized GLP-1 and Gly8 also performed poorly compared to exendin-4-based constructs in vitro, suggesting that conditioned-media potency screening is a valid early filter for construct selection in vectorized-peptide AAV development. Engineering peptides to improve translation and secretion efficiency, in addition to circulating plasma stability, could further optimize vectorized GLP-1RA therapeutics.

pharmacology and toxicology↗

Preclinical Evaluation of a Novel BOC-Modified Triazoloacridinone (TRA-01AR) in Combination with 5-Fluorouracil in Colorectal Cancer

5-Fluorouracil (5-FU) remains a cornerstone of colorectal cancer (CRC) therapy, yet its clinical efficacy is limited by resistance, systemic toxicity, and unfavorable pharmacokinetics. Strategies that enhance tumor sensitivity while maintaining tolerability are therefore of considerable interest. Here, we evaluated 5-FU in combination with two triazoloacridinones, C-1305 and a novel BOC-modified derivative, TRA-01AR, using integrated cellular, transcriptomic, bioenergetic, and in vivo approaches. Both compounds induced cytotoxic effects across cancer cell models and produced overlapping but distinct transcriptional responses, primarily affecting DNA replication and cell cycle pathways. Bioenergetic profiling revealed a shift toward oxidative phosphorylation accompanied by reduced glycolysis, indicating modulation of cellular metabolism relevant to chemotherapy response. Interestingly, TRA-01AR exhibited delayed cytotoxicity relative to C-1305, although the underlying mechanism remains to be defined. In vivo, the combination of 5-FU with C-1305 significantly reduced tumor weight in HT-29 xenografts, whereas 5-FU combined with TRA-01AR did not result in a statistically significant reduction compared to 5-FU alone. TRA-01AR was associated with a more favorable systemic profile and increased intratumoral blood flow compared with C-1305. Collectively, these findings indicate that triazoloacridinones modulate transcriptional and metabolic programs relevant to the 5-FU response. While C-1305 demonstrated greater antitumor activity under the tested conditions, TRA-01AR exhibited distinct biological effects, including improved tolerability and vascular modulation. Further studies are required to clarify TRA-01AR's mechanism of action and assess its potential relevance in CRC-specific therapies.

pharmacology and toxicology↗