The diagnostic role of AIM2 in Kawasaki disease

AIM2 targeting of nuclear DNA leakage in dendritic cells exacerbates vasculitis in a murine model of Kawasaki disease

Kawasaki disease (KD) is an acute vasculitis that mostly affects children and is characterized by inflammation of medium-sized arteries, particularly the coronary arteries. The absent in melanoma 2 (AIM2) inflammasome senses cytosolic dsDNA and regulates IL-1β-driven inflammation. We investigated the role of AIM2 in Candida albicans water-soluble fraction (CAWS)-induced vasculitis in a murine model mimicking KD. Aim2-/- mice exhibited reduced vasculitis, inflammatory cell infiltration, and vascular fibrosis in the aorta and coronary arteries. In addition, dsDNA damage was detected in Dectin-2+ cells infiltrating vasculitis areas. In vitro experiments showed that CAWS induced dsDNA damage in Dectin-2+ bone marrow-derived dendritic cells (BMDCs) isolated from wild-type (WT) and Aim2-/- mice. Furthermore, CAWS induces nuclear membrane deformation and DNA leakage into the cytosol, leading to AIM2 inflammasome activation and subsequent IL-1β production in WT BMDC. These findings suggest that AIM2 inflammasome activation in dendritic cells, triggered by dsDNA damage and leakage, contributes to the development of CAWS-induced vasculitis, and provides important insights into the inflammatory mechanisms underlying KD.NEW & NOTEWORTHY The AIM2 inflammasome in dendritic cells is a significant component of the murine model of Kawasaki disease-like vasculitis induced by CAWS injection. The AIM2 deficiency reduces vasculitis via reduced inflammatory cell infiltration and vascular fibrosis in CAWS-induced vasculitis. CAWS induces the damage and leakage of nuclear DNA in dendritic cells, which triggers AIM2 inflammasome activation, leading to an IL-1β-driven inflammatory response.

Role of Pyroptosis in IVIG-Resistant Kawasaki Disease and the Establishment of a New Predictive Model

Background

Intravenous immunoglobulin (IVIG) resistance may be an increased risk of coronary artery lesions which is the serious complication of Kawasaki disease (KD). Early and accurate identification of IVIG-resistant patients has an important clinical value.

Objective

To establish a new predicting model by detecting the pyroptosis markers with other clinical indicators.

Methods

A total of 144 children with KD who were hospitalized in Wuhan Children's Hospital from January 2022 to December 2022 were enrolled in this prospective study, among whom 120 had IVIG-sensitive KD and 24 had IVIG-resistant KD. NLRP3, ASC, CASP1, and GSDMD were quantified in peripheral blood cells of all children by using Real-time Quantitative Polymerase Chain Reaction (QRT-PCR) assay. The enzyme-linked immunosorbent assay (ELISA) was used to measure the serum levels of cytokines like IL-1β and IL-18. Logistic regression analysis was performed to identify independent risk factors for resistance to IVIG in children with KD. These meaningful variables were assigned values based on odds ratios and became components of the new risk assessment model. The prediction efficiency of this model was tested and evaluated based on the receiver operating characteristic (ROC) curves.

Results

1. IVIG-resistant KD group had significantly lower mRNA expression of CASP1 than IVIG-sensitive KD group (P<0.05). 2. IVIG-resistant KD group had significantly higher level of serum procalcitonin (PCT) and tumor necrosis factor-α (TNF-α) and lower level of serum natrium (Na) than the IVIG-sensitive KD group (P<0.05). 3. The assessment model had a sensitivity of 91.7% and a specificity of 69.2% in the prediction of IVIG-resistant KD (P<0.001).

Conclusion

Combined examination by CASP1 and above laboratory indexes has clinical practical value for the diagnosis of IVIG-resistant KD.

Promising biomarkers of Kawasaki disease: markers that aid in diagnosis

INTRODUCTION

Currently the diagnosis of Kawasaki disease is still heavily reliant on clinical criteria which may be subject to interpretation or mimic other common febrile diseases of childhood. Biomarkers that can aid in the accurate and timely diagnosis of KD are of great clinical utility.

AREAS COVERED

A literature search of PubMed was performed using the key words: Kawasaki disease, diagnosis, biomarkers, proteomics and transcriptomics. In this article we review biomarkers that are widely clinically available including NT-ProBNP and ferritin. We also include promising novel biomarkers that have been identified through newer transcriptomic and proteomic techniques.

EXPERT OPINION

While the identification of biomarkers that can accurately assist in diagnosing patients with KD is a promising field of research, more still remains to be done to in order to validate new biomarkers in larger cohorts, and to set standardized cutoff values for potential biomarkers that are currently clinically available. Further research is needed before KD biomarkers that are consistent, readily available, and cost-effective can be a clinical reality.

The cytoplasmic sensor, the AIM2 inflammasome: A precise therapeutic target in vascular and metabolic diseases

Cardio-cerebrovascular diseases encompass pathological changes in the heart, brain and vascular system, which pose a great threat to health and well-being worldwide. Moreover, metabolic diseases contribute to and exacerbate the impact of vascular diseases. Inflammation is a complex process that protects against noxious stimuli but is also dysregulated in numerous so-called inflammatory diseases, one of which is atherosclerosis. Inflammation involves multiple organ systems and a complex cascade of molecular and cellular events. Numerous studies have shown that inflammation plays a vital role in cardio-cerebrovascular diseases and metabolic diseases. The absent in melanoma 2 (AIM2) inflammasome detects and is subsequently activated by double-stranded DNA in damaged cells and pathogens. With the assistance of the mature effector molecule caspase-1, the AIM2 inflammasome performs crucial biological functions that underpin its involvement in cardio-cerebrovascular diseases and related metabolic diseases: The production of interleukin-1 beta (IL-1β), interleukin-18 (IL-18) and N-terminal pore-forming Gasdermin D fragment (GSDMD-N) mediates a series of inflammatory responses and programmed cell death (pyroptosis and PANoptosis). Currently, several agents have been reported to inhibit the activity of the AIM2 inflammasome and have the potential to be evaluated for use in clinical settings. In this review, we systemically elucidate the assembly, biological functions, regulation and mechanisms of the AIM2 inflammasome in cardio-cerebrovascular diseases and related metabolic diseases and outline the inhibitory agents of the AIM2 inflammasome as potential therapeutic drugs.

The AIM2 inflammasome: A novel biomarker and target in cardiovascular disease

Absent in melanoma 2 (AIM2) is a cytoplasmic sensor that recognises the double-strand DNA. AIM2 inflammasome is a protein platform in the cell that initiates innate immune responses by cleaving pro-caspase-1 and converting IL-1β and IL-18 to their mature forms. Additionally, AIM2 inflammasome promotes pyroptosis by converting Gasdermin-D (GSDMD) to GSDMD-N fragments. An increasing number of studies have indicated the important and decisive roles of the AIM2 inflammasome, IL-1β, and pyroptosis in cardiovascular diseases, such as coronary atherosclerosis, myocardial infarction, ischaemia/reperfusion injury, heart failure, aortic aneurysm and ischaemic stroke. Here, we review the molecular mechanism of the activation and effect of the AIM2 inflammasome in cardiovascular disease, revealing new insights into pathogenic factors that may be targeted to treat cardiovascular disease and related dysfunctions.