Genome-wide transcriptome analysis to further understand neutrophil activation and lncRNA transcript profiles in Kawasaki disease

Exploring the role of exosomal and non-exosomal non-coding RNAs in Kawasaki disease: Implications for diagnosis and therapeutic strategies against coronary artery aneurysms

Kawasaki disease (KD) is an acute vasculitis primarily affecting children, with a potential risk of developing coronary artery aneurysms (CAAs) and cardiovascular complications. The emergence of non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), has provided insights into Kawasaki disease pathogenesis and opened new avenues for diagnosis and therapeutic intervention. Furthermore, polymorphism analysis of ncRNA genes offers significant insights into genetic predisposition to Kawasaki disease, facilitating tailored treatment approaches and risk assessment to improve patient outcomes. Exosomal ncRNAs, which are ncRNAs encapsulated within extracellular vesicles, have garnered significant attention as potential biomarkers for Kawasaki disease and CAA due to their stability and accessibility in biological fluids. This review comprehensively discusses the biogenesis, components, and potential of exosomal and non-exosomal ncRNAs in Kawasaki disease diagnosis and prognosis prediction. It also highlights the roles of non-exosomal ncRNAs, such as miRNAs, lncRNAs, and circRNAs, in Kawasaki disease pathogenesis and their implications as therapeutic targets. Additionally, the review explores the current diagnostic and therapeutic approaches for Kawasaki disease and emphasizes the need for further research to validate these ncRNA-based biomarkers in diverse populations and clinical settings.

Single-cell RNA sequencing: an emerging tool revealing dysregulated innate and adaptive immune response at single cell level in Kawasaki disease

INTRODUCTION

Kawasaki disease [KD] is a systemic disorder characterized by acute febrile illness due to widespread medium-vessel vasculitis, mainly affecting children. Despite the ongoing advanced research into the disease pathophysiology and molecular mechanisms, the exact etiopathogenesis of KD is still an enigma. Recently, single-cell RNA sequencing [scRNA-seq], has been utilized to elucidate the pathophysiology of KD at a resolution higher than that of previous methods.

AREA COVERED

In the present article, we re-emphasize the pivotal role of this high-resolution technique, scRNA-seq, in the characterization of immune cell transcriptomic profile and signaling/response pathways in KD and explore the diagnostic, prognostic, and therapeutic potential of this new technique in KD. Using combinations of the search phrases 'KD, scRNA-seq, CAA, childhood vasculitis' a literature search was carried out on Scopus, Google Scholar, and PubMed until the beginning of 2024.

EXPERT OPINION

scRNA-seq presents a transformative tool for dissecting KD at the cellular level. By revealing rare cell populations, gene expression alterations, and disease-specific pathways, scRNA-seq aids in understanding the intricacies of KD pathogenesis. This review will provide new insights into pathogenesis of KD and the field of applications of scRNA-seq in personalized therapeutics for KD in the future.

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.

LncRNAs in Kawasaki disease and Henoch-Schönlein purpura: mechanisms and clinical applications

Kawasaki disease (KD) and Henoch-Schönlein purpura (HSP) are the two most predominant types of childhood vasculitis. In childhood vasculitis, factors such as lack of sensitive diagnostic indicators and adverse effects of drug therapy may cause multiorgan system involvement and complications and even death. Many studies suggest that long noncoding RNAs (lncRNAs) are involved in the mechanism of vasculitis development in children and can be used to diagnose or predict prognosis by lncRNAs. In existing drug therapies, lncRNAs are also involved in drug-mediated treatment mechanisms and are expected to improve drug toxicity. The aim of this review is to summarize the link between lncRNAs and the pathogenesis of KD and HSP. In addition, we review the potential applications of lncRNAs in multiple dimensions, such as diagnosis, treatment, and prognosis prediction. This review highlights that targeting lncRNAs may be a novel therapeutic strategy to improve and treat KD and HSP.

The state of play in tools for predicting immunoglobulin resistance in Kawasaki disease

INTRODUCTION

Intravenous immunoglobulin (IVIG) resistance is an independent risk factor for the development of coronary artery lesions (CAL) in patients with Kawasaki disease (KD). Accurate identification of IVIG-resistant patients is one of the biggest clinical challenges in the treatment of KD.

AREAS COVERED

In this review article, we will go over current IVIG resistance scoring systems and other biological markers of IVIG resistance, with a particular focus on advances in machine-based learning techniques and high-throughput omics data.

EXPERT OPINION

Traditional scoring models, which were developed using logistic regression, including the Kobayashi score and Egami score, are inadequate at identifying IVIG resistance in non-Japanese populations. Newer machine-learning methods and high-throughput technologies including transcriptomic and epigenetic arrays have identified several potential targets for IVIG resistance including gene expression of the Fc receptor, and components of the interleukin (IL)-1β and pyroptosis pathways. As we enter an age where access to big data has become more commonplace, interpretation of large data sets that are able take into account complexities in patient populations will hopefully usher in a new era of precision medicine, which will enable us to identify and treat KD patients with IVIG resistance with increased accuracy.

Identification of key signaling pathways and hub genes related to immune infiltration in Kawasaki disease with resistance to intravenous immunoglobulin based on weighted gene co-expression network analysis

Background: Kawasaki disease (KD) is an acute vasculitis, that is, the leading cause of acquired heart disease in children, with approximately 10%-20% of patients with KD suffering intravenous immunoglobulin (IVIG) resistance. Although the underlying mechanism of this phenomenon remains unclear, recent studies have revealed that immune cell infiltration may associate with its occurrence. Methods: In this study, we downloaded the expression profiles from the GSE48498 and GSE16797 datasets in the Gene Expression Omnibus database, analyzed differentially expressed genes (DEGs), and intersected the DEGs with the immune-related genes downloaded from the ImmPort database to obtain differentially expressed immune-related genes (DEIGs). Then CIBERSORT algorithm was used to calculate the immune cell compositions, followed by the WGCNA analysis to identify the module genes associated with immune cell infiltration. Next, we took the intersection of the selected module genes and DEIGs, then performed GO and KEGG enrichment analysis. Moreover, ROC curve validation, Spearman analysis with immune cells, TF, and miRNA regulation network, and potential drug prediction were implemented for the finally obtained hub genes. Results: The CIBERSORT algorithm showed that neutrophil expression was significantly higher in IVIG-resistant patients compared to IVIG-responsive patients. Next, we got differentially expressed neutrophil-related genes by intersecting DEIGs with neutrophil-related module genes obtained by WGCNA, for further analysis. Enrichment analysis revealed that these genes were associated with immune pathways, such as cytokine-cytokine receptor interaction and neutrophil extracellular trap formation. Then we combined the PPI network in the STRING database with the MCODE plugin in Cytoscape and identified 6 hub genes (TLR8, AQP9, CXCR1, FPR2, HCK, and IL1R2), which had good diagnostic performance in IVIG resistance according to ROC analysis. Furthermore, Spearman's correlation analysis confirmed that these genes were closely related to neutrophils. Finally, TFs, miRNAs, and potential drugs targeting the hub genes were predicted, and TF-, miRNA-, and drug-gene networks were constructed. Conclusion: This study found that the 6 hub genes (TLR8, AQP9, CXCR1, FPR2, HCK, and IL1R2) were significantly associated with neutrophil cell infiltration, which played an important role in IVIG resistance. In a word, this work rendered potential diagnostic biomarkers and prospective therapeutic targets for IVIG-resistant patients.

Use of Host Response to Refine the Diagnosis of Group A Streptococcal Pharyngitis

BACKGROUND

Current diagnostic tests for pharyngitis do not distinguish between symptomatic group A Streptococcus (GAS) infection and asymptomatic colonization, resulting in over-diagnosis and unnecessary use of antibiotics. We assessed whether measures of host response could make this distinction.

METHODS

We enrolled 18 children with pharyngitis having Centor scores of 4 or 5 and 21 controls without pharyngitis or other acute infections. Both groups had throat cultures, molecular tests for GAS and respiratory viruses and IgM serology for Epstein-Barr virus. Host response was evaluated with white blood cell count (WBC), C-reactive protein (CRP), procalcitonin (PCT), and sequencing of RNA from peripheral blood leukocytes.

RESULTS

Of 18 cases, 11 had GAS pharyngitis, 3 had adenovirus pharyngitis and 4 had other pharyngitis. Among asymptomatic controls, 5 were positive for GAS. WBC, CRP, and PCT were higher in subjects with pharyngitis compared to asymptomatic controls including those with GAS. Transcriptional profiles from children with symptomatic GAS were clearly distinct from those of children in all other groups. The levels of two genes, CD177 and TLR5 each individually accurately distinguished between symptomatic and asymptomatic GAS. Optimal diagnostic sensitivity and specificity were achieved by the combination of CRP and PCT, and by each of the two gene markers.

CONCLUSION

In this exploratory study, we showed that traditional measures of inflammation and markers of host gene expression distinguish between symptomatic and asymptomatic GAS. These results point to future rapid molecular approaches for improving the diagnosis of GAS pharyngitis, that may help reduce unnecessary antibiotic use.

The neutrophil: A key resourceful agent in immune‐mediated vasculitis

The term "vasculitis" refers to a group of rare immune-mediated diseases characterized by the dysregulated immune system attacking blood vessels located in any organ of the body, including the skin, lungs, and kidneys. Vasculitides are classified according to the size of the vessel that is affected. Although this observation is not specific to small-, medium-, or large-vessel vasculitides, patients show a high circulating neutrophil-to-lymphocyte ratio, suggesting the direct or indirect involvement of neutrophils in these diseases. As first responders to infection or inflammation, neutrophils release cytotoxic mediators, including reactive oxygen species, proteases, and neutrophil extracellular traps. If not controlled, this dangerous arsenal can injure the vascular system, which acts as the main transport route for neutrophils, thereby amplifying the initial inflammatory stimulus and the recruitment of immune cells. This review highlights the ability of neutrophils to "set the tone" for immune cells and other cells in the vessel wall. Considering both their long-established and newly described roles, we extend their functions far beyond their direct host-damaging potential. We also review the roles of neutrophils in various types of primary vasculitis, including immune complex vasculitis, anti-neutrophil cytoplasmic antibody-associated vasculitis, polyarteritis nodosa, Kawasaki disease, giant cell arteritis, Takayasu arteritis, and Behçet's disease.

Using bioinformatics analysis to screen abnormal methylated differentially expressed hub genes of Kawasaki disease and construct diagnostic model

OBJECTIVE

By using bioinformatics analysis, abnormal methylated differentially expressed genes (MDEGs) in Kawasaki disease (KD) were identified and a random forest diagnostic model for KD was established.

METHODS

The expression (GSE18606, GSE68004, GSE73461) and methylation (GSE109430) profiles was retrieved and download from Gene Expression Omnibus (GEO). We conducted enrichment analyses by using R software. In addition, we constructed a protein interaction network, and obtained 6 hub genes. We used expression profiles GSE100154 from GEO to verify the hub genes. Finally, we constructed a diagnostic model based on random forest.

RESULTS

We got a total of 55 MDEGs (43 hyper-methylated, low-expressing genes and 12 hypo-methylated, high-expressed genes). Six hub genes (CD2, IL2RB, IL7R, CD177, IL1RN, and MYL9) were identified by Cytoscape software. The area under curve (AUC) of the six hub genes was from 0.745 to 0.898, and the combined AUC was 0.967. The random forest diagnostic model showed that AUC was 0.901.

CONCLUSION

The identification of 6 new hub genes improves our understanding of the molecular mechanism of KD, and the established model can be employed for accurate diagnosis and provide evidence for clinical diagnosis.

Comparable bidirectional neutrophil immune dysregulation between Kawasaki disease and severe COVID-19

Kawasaki disease (KD), a multisystem inflammatory syndrome that occurs in children, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or COVID-19) may share some overlapping mechanisms. The purpose of this study was to analyze the differences in single-cell RNA sequencing between KD and COVID-19. We performed single-cell RNA sequencing in KD patients (within 24 hours before IVIG treatment) and age-matched fever controls. The single-cell RNA sequencing data of COVID-19, influenza, and health controls were downloaded from the Sequence Read Archive (GSE149689/PRJNA629752). In total, 22 single-cell RNA sequencing data with 102,355 nuclei were enrolled in this study. After performing hierarchical and functional clustering analyses, two enriched gene clusters demonstrated similar patterns in severe COVID-19 and KD, heightened neutrophil activation, and decreased MHC class II expression. Furthermore, comparable dysregulation of neutrophilic granulopoiesis representing two pronounced hyperinflammatory states was demonstrated, which play a critical role in the overactivated and defective aging program of granulocytes, in patients with KD as well as those with severe COVID-19. In conclusion, both neutrophil activation and MHC class II reduction play a crucial role and thus may provide potential treatment targets for KD and severe COVID-19.

Kawasaki disease: SOCS2-AS1/miR-324-5p/CUEDC2 axis regulates the progression of human umbilical vein endothelial cells

BACKGROUND

Kawasaki disease (KD) is the most prevailing cause of acquired heart disease in children, due to permanent coronary artery damage. Recently, the role of long noncoding RNAs (lncRNAs) in human diseases has been highlighted. However, the role of lncRNA SOCS2 antisense RNA 1 (SOCS2-AS1) on the function of human umbilical vein endothelial cells (HUVECs) in KD remains elusive.

METHODS

SOCS2-AS1 expression was examined via RT-qPCR. CCK-8, EdU, caspase-3 activity, flow cytometry and TUNEL assays were conducted for exploring the function of SOCS2-AS1 in HUVECs of KD. The interaction among RNAs (SOCS2-AS1, miR-324-5p and CUEDC2) was validated via luciferase reporter, RIP and RNA pull-down assays.

RESULTS

SOCS2-AS1 was highly expressed in serum and tissues of KD patients. SOCS2-AS1 depletion repressed the proliferation of HUVECs, whereas it facilitated apoptosis. Further, SOCS2-AS1 could bind with miR-324-5p and negatively regulated miR-324-5p expression in HUVECs. Besides, CUE domain containing 2 (CUEDC2) was the downstream target of miR-324-5p, and SOCS2-AS1 could release CUEDC2 expression via sponging miR-324-5p in HUVECs. Furthermore, downregulating miR-324-5p or upregulating CUEDC2 could rescue the progression of HUVECs restrained by SOCS2-AS1 knockdown.

CONCLUSIONS

SOCS2-AS1 upregulates CUEDC2 via inhibiting miR-324-5p to promote the progression of HUVECs in KD, providing new insights for KD treatment.

IMPACT

SOCS2-AS1 is highly expressed in the serum of KD patients. SOCS2-AS1 contributes to cell proliferation in HUVECs of KD through elevating CUEDC2 expression by sequestering miR-324-5p. SOCS2-AS1/miR-324-5p/CUEDC2 axis exerts a progression-facilitating function in KD. These findings suggest SOCS2-AS1 as a novel potential target for KD treatment.

Comparison of High-Throughput Technologies in the Classification of Adult-Onset Still's Disease Patients

A meta-analysis study was conducted to compare high-throughput technologies in the classification of Adult-Onset Still's Disease patients, using differentially expressed genes from independent profiling experiments. We exploited two publicly available datasets from the Gene Expression Omnibus and performed a separate differential expression analysis on each dataset to extract statistically important genes. We then mapped the genes of the two datasets and subsequently we employed well-established machine learning algorithms to evaluate the denoted genes as candidate biomarkers. Using next-generation sequencing data, we managed to achieve the maximum (100%) classification accuracy, sensitivity and specificity with the Gradient Boosting and the Random Forest classifiers, compared to the 83% of the DNA microarray data. Clinical Relevance- When biomarkers derived from one study are applied to the data of another, in many cases the results may diverge significantly. Here we establish that in cross-profiling meta-analysis approaches based on differential expression analysis, next-generation sequencing data provide more accurate results than microarray experiments in the classification of Adult-Onset Still's Disease patients.

Efficacy of Glucocorticoid plus Intravenous Immunoglobulin in Children with Immunoglobulin-Insensitive Kawasaki Disease

This study mainly analyzes the clinical effect of glucocorticoid (GC) plus intravenous immunoglobulin (IVIG) in treating children with immunoglobulin (Ig)-insensitive Kawasaki disease (KD). From September 2013 to November 2021, 86 Ig-insensitive KD children were selected, including 46 children (observation group, Obs) treated with GC plus IVIG, and 40 children (control group, Con) treated with IVIG. The symptom (fever and fever) resolution time, inflammatory factors (C-reactive protein, CRP; procalcitonin, PCT; interleukin-6, IL-6), immune indicators (CD3+, CD4+, CD8+ T lymphocytes CD3+, CD4+, and CD4+/CD8+), and incidence of adverse reactions were compared between the groups. The results identified shorter fever and rash resolution time in Obs compared with Con. The posttreatment CRP, PCT, IL-6, and CD8+ and the incidence of adverse events reduced notably in Obs and were lower than Con, while CD3+, CD4+, and CD4+/CD8+ elevated statistically and were higher than that of Con. Our results indicate that GC plus IVIG can significantly promote symptom resolution, alleviate inflammatory response, and improve immune function in children with Ig-insensitivity KD, with favorable safety and clinical promotion value.

Non-coding RNAs in Kawasaki disease: Molecular mechanisms and clinical implications

Kawasaki disease (KD) is an acute self-limiting vasculitis with coronary complications, usually occurring in children. The incidence of KD in children is increasing year by year, mainly in East Asian countries, but relatively stably in Europe and America. Although studies on KD have been reported, the pathogenesis of KD is unknown. With the development of high-throughput sequencing technology, growing number of regulatory noncoding RNAs (ncRNAs) including microRNA (miRNA), long noncoding RNA (lncRNA), and circular RNA (circRNA) have been identified to involved in KD. However, the role of ncRNAs in KD has not been comprehensively elucidated. Therefore, it is significative to study the regulatory role of ncRNA in KD, which might help to uncover new and effective therapeutic strategies for KD. In this review, we summarize recent studies on ncRNA in KD from the perspectives of immune disorders, inflammatory disorders, and endothelial dysfunction, and highlight the potential of ncRNAs as therapeutic targets for KD.

Kawasaki disease: lncRNA Slco4a1 regulates the progression of human umbilical vein endothelial cells by targeting the miR-335-5p/POU5F1 axis

BACKGROUND

Kawasaki disease (KD) is an autoimmune disease with systemic vasculitis as the main pathological change, and is most common in children under 5. The role of long non-coding RNAs (lncRNAs) in human diseases has been highlighted. LncRNA Slco4a1 was reported to promote cell growth and act as an oncogenic regulator in cancer. However, the role of lncRNA Slco4a1 in KD remains unclear. This study aimed to investigate the role and mechanism of lncRNA Slco4a1 in KD.

METHODS

Enzyme linked immunosorbent assay (ELISA), qRT-PCR, Western blot, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining were conducted to explore the function of lncRNA Slco4a1. The interaction between POU5F1 and miR-335-5p was analyzed by the RIP assay and dual luciferase assay.

RESULTS

LncRNA Slco4a1 was significantly upregulated in the serum of KD patients compared with healthy controls. LncRNA Slco4a1 was upregulated in human umbilical vein endothelial cells (HUVECs) stimulated with KD serum. LncRNA Slco4a1 overexpression could promote the expression of inflammatory factors and apoptosis in HUVECs. The number of inflammatory cells and the infiltration area of the coronary artery in KD rats were decreased after lncRNA Slco4a1 silencing. Furthermore, lncRNA Slco4a1 is a sponge of miR-335-5p and negatively regulated the expression of miR-335-5p. POU5F1 was the downstream target of miR-335-5p, and miR-335-5p overexpression could upregulate the expression of POU5F1. Additionally, miR-335-5p overexpression could inhibit the expression of inflammatory factors and apoptosis in HUVECs. We further investigated the effect of lncRNA Slco4a1 on the mitogen-activated protein kinase (MAPK) signaling pathway, and the results showed that lncRNA Slco4a1 could promote the activation of the MAPK signaling pathway.

CONCLUSIONS

Together, these results indicated that lncRNA Slco4a1 could regulate the progression of HUVECs in KD by targeting the miR-335-5p/POU5F1 axis, providing new insights for KD treatment.

G0S2 regulates innate immunity in Kawasaki disease via lncRNA HSD11B1-AS1

BACKGROUND

Kawasaki disease (KD) is a systemic vasculitis that is currently the most common cause of acquired heart disease in children. However, its etiology remains unknown. Long non-coding RNAs (lncRNAs) contribute to the pathophysiology of various diseases. Few studies have reported the role of lncRNAs in KD inflammation; thus, we investigated the role of lncRNA in KD inflammation.

METHODS

A total of 50 patients with KD (median age, 19 months; 29 males and 21 females) were enrolled. We conducted cap analysis gene expression sequencing to determine differentially expressed genes in monocytes of the peripheral blood of the subjects.

RESULTS

About 21 candidate lncRNA transcripts were identified. The analyses of transcriptome and gene ontology revealed that the immune system was involved in KD. Among these genes, G0/G1 switch gene 2 (G0S2) and its antisense lncRNA, HSD11B1-AS1, were upregulated during the acute phase of KD (P < 0.0001 and <0.0001, respectively). Moreover, G0S2 increased when lipopolysaccharides induced inflammation in THP-1 monocytes, and silencing of G0S2 suppressed the expression of HSD11B1-AS1 and tumor necrosis factor-α.

CONCLUSIONS

This study uncovered the crucial role of lncRNAs in innate immunity in acute KD. LncRNA may be a novel target for the diagnosis of KD.

IMPACT

This study revealed the whole aspect of the gene expression profile of monocytes of patients with Kawasaki disease (KD) using cap analysis gene expression sequencing and identified KD-specific molecules: G0/G1 switch gene 2 (G0S2) and long non-coding RNA (lncRNA) HSD11B1-AS1. We demonstrated that G0S2 and its antisense HSD11B1-AS1 were associated with inflammation of innate immunity in KD. lncRNA may be a novel key target for the diagnosis of patients with KD.

Diagnostic significance of noncoding RNAs in kawasaki disease: A systematic review and meta-analysis

OBJECTIVE

Kawasaki disease (KD) is a systemic vasculitis disease, and early effective intervention would reduce the occurrence of coronary artery lesions (CALs). Recently, many scholars have been committed to studying the relationship between noncoding RNAs and KD. This systematic review aimed to analyze the diagnostic value of noncoding RNAs(ncRNAs) in distinguishing different KD status.

METHODS

We searched for the literature about diagnostic values of ncRNAs in KD in CNKI, VIP, Wanfang, China Biomedical Literature Database as well as PubMed, Web of Science, Embase, and Cochrane Library up to April 15, 2022. All included studies were further analyzed using STATA 12.0, Meta-disc 1.4 and RevMan 5.4 software.

RESULTS

A total of six studies investigating the diagnostic performance of ncRNAs in differentiating KD-CAL (n = 101) from KD-NCAL patients (n = 123) were included in this this meta-analysis. The calculated area under the curve(AUC) was 0.83 (0.80-0.86). Four studies on the diagnostic performance of ncRNAs in differentiating acute KD patients (n = 139) from convalescent KD patients (n = 109) were included. The calculated AUC was 0.87 (0.84-0.90). Four studies focused on the diagnostic performance of ncRNAs combined with other laboratory indexes in KD by assessing 137 KD patients and 152 febrile controls. The calculated AUC was 0.90 (0.87-0.92). Four studies assessed the diagnostic performance of ncRNAs in differentiating intravenous immunoglobulin (IVIG)-resistant KD patients from IVIG-responsive KD patients. The calculated AUC was 0.9135 ± 0.0307. These results indicated that ncRNAs have a good diagnostic efficacy in KD.

CONCLUSIONS

This meta-analysis showed that ncRNAs have potential as a biomarker for distinguishing different KD status. However, since limited studies were included in this meta-analysis, larger and well-designed diagnostic studies should be conducted to validate these results.

SYSTEMATIC REVIEW REGISTRATION

INPLASY.COM, identifier: doi: 10.37766/inplasy2022.10.0035.

Current Understanding of the Neutrophil Transcriptome in Health and Disease

Neutrophils are key cells of the innate immune system. It is now understood that this leukocyte population is diverse in both the basal composition and functional plasticity. Underlying this plasticity is a post-translational framework for rapidly achieving early activation states, but also a transcriptional capacity that is becoming increasingly recognized by immunologists. Growing interest in the contribution of neutrophils to health and disease has resulted in more efforts to describe their transcriptional activity. Whilst initial efforts focused predominantly on understanding the existing biology, investigations with advanced methods such as single cell RNA sequencing to understand interactions of the entire immune system are revealing higher flexibility in neutrophil transcription than previously thought possible and multiple transition states. It is now apparent that neutrophils utilise many forms of RNA in the regulation of their function. This review collates current knowledge on the nuclei structure and gene expression activity of human neutrophils across homeostasis and disease, before highlighting knowledge gaps that are research priority areas.

Epigenetics in Kawasaki Disease

Kawasaki disease (KD) is a common febrile multisystemic inflammatory illness in children that preferentially affects coronary arteries. Children with KD who develop coronary artery aneurysms have a life-long risk of premature coronary artery disease. Hypothesis of inherent predisposition to KD is supported by epidemiological evidence that suggests increased risk of development of disease in certain ethnicities and in children with a previous history of KD in siblings or parents. However, occurrence of cases in clusters, seasonal variation, and very low risk of recurrence suggests an acquired trigger (such as infections) for the development of illness. Epigenetic mechanisms that modulate gene expression can plausibly explain the link between genetic and acquired predisposing factors in KD. Analysis of epigenetic factors can also be used to derive biomarkers for diagnosis and prognostication in KD. Moreover, epigenetic mechanisms can also help in pharmacogenomics with the development of targeted therapies. In this review, we analysed the available literature on epigenetic factors such as methylation, micro-RNAs, and long non-coding RNAs in KD and discuss how these mechanisms can help us better understand the disease pathogenesis and advance the development of new biomarkers in KD.

Utilizing single-cell RNA sequencing for analyzing the characteristics of PBMC in patients with Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is the main cause of acquired heart disease in children and can lead to coronary artery lesions. This present study was designed to analyze the characteristics of KD peripheral blood mononuclear cells (PBMC) through single-cell RNA sequencing (scRNA-seq) and to explore the potential molecular mechanism of KD.

METHODS

PBMC was collected from one healthy child and one KD patient, and was used to single-cell RNA sequencing for cell clusters identification and differently expressed gene (DEG) determination. GO function enrichment analysis of DEG in B cell and T cells were performed to explore the most active biological function in KD immune cells.

RESULTS

Twelve cell clusters can be identified in two samples. Compared with healthy child, naive CD8+ T cell, T helper cell and B cell in KD child were decreased, mainly immune-related T cells, and natural killer T (NKT) cell were increased. Cell activation, lymphocyte activation and regulation of immune system process were 3 GO function shared by all four types of T cells and B cell.

CONCLUSIONS

Immune cell disorder appears in the KD patient at single cell level by scRNA-seq.

CD177, a specific marker of neutrophil activation, is associated with coronavirus disease 2019 severity and death

The identification of patients with coronavirus disease 2019 and high risk of severe disease is a challenge in routine care. We performed cell phenotypic, serum, and RNA sequencing gene expression analyses in severe hospitalized patients (n = 61). Relative to healthy donors, results showed abnormalities of 27 cell populations and an elevation of 42 cytokines, neutrophil chemo-attractants, and inflammatory components in patients. Supervised and unsupervised analyses revealed a high abundance of CD177, a specific neutrophil activation marker, contributing to the clustering of severe patients. Gene abundance correlated with high serum levels of CD177 in severe patients. Higher levels were confirmed in a second cohort and in intensive care unit (ICU) than non-ICU patients (P < 0.001). Longitudinal measurements discriminated between patients with the worst prognosis, leading to death, and those who recovered (P = 0.01). These results highlight neutrophil activation as a hallmark of severe disease and CD177 assessment as a reliable prognostic marker for routine care.

Differentially expressed genes, lncRNAs, and competing endogenous RNAs in Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is an acute and febrile systemic vasculitis of unknown etiology. This study aimed to identify the competing endogenous RNA (ceRNA) networks of lncRNAs, miRNAs, and genes in KD and explore the molecular mechanisms underlying KD.

METHODS

GSE68004 and GSE73464 datasets were downloaded from the Gene Expression Omnibus. Differentially expressed lncRNAs (DElncRNAs) and genes (DEGs) in KD were identified using the criteria of p < 0.05 and | log2 (fold change) | ≥ 1. MicroRNAs (miRNAs) related to KD were searched from databases. The lncRNA-miRNA-mRNA networks involving the DElncRNAs and DEGs were constructed.

RESULTS

A total of 769 common upregulated, 406 common downregulated DEGs, and six DElncRNAs were identified in the KD samples. The lncRNA-miRNA-mRNA network consisted of four miRNAs, three lncRNAs (including the upregulated PSORS1C3, LINC00999, and the downregulated SNHG5) and four DEGs (including the downregulated GATA3 and the upregulated SOD2, MAPK14, and PPARG). Validation in the GSE18606 dataset showed that intravenous immunoglobulin treatment significantly alleviated the deregulated profiles of the above RNAs in KD patients. Three ceRNA networks of LINC00999-hsa-miR-6780-SOD2, PSORS1C3-hsa-miR-216a-PPARG/MAPK14, and SNHG5-hsa-miR-132/hsa-miR-92-GATA3 were identified. Four genes were associated with functional categories, such as inflammatory response and vascular endothelial cell.

CONCLUSIONS

The ceRNA networks involve genes, such as SOD2, MAPK14, and PPARG, and lncRNAs, including PSORS1C3, LINC00999, and SNHG5, which might play a key role in the pathogenesis and development of KD by regulating inflammation.

In silico Identification of 10 Hub Genes and an miRNA-mRNA Regulatory Network in Acute Kawasaki Disease

Kawasaki disease (KD) causes acute systemic vasculitis and has unknown etiology. Since the acute stage of KD is the most relevant, the aim of the present study was to identify hub genes in acute KD by bioinformatics analysis. We also aimed at constructing microRNA (miRNA)–messenger RNA (mRNA) regulatory networks associated with acute KD based on previously identified differentially expressed miRNAs (DE-miRNAs). DE-mRNAs in acute KD patients were screened using the mRNA expression profile data of GSE18606 from the Gene Expression Omnibus. The functional and pathway enrichment analysis of DE-mRNAs were performed with the DAVID database. Target genes of DE-miRNAs were predicted using the miRWalk database and their intersection with DE-mRNAs was obtained. From a protein–protein interaction (PPI) network established by the STRING database, Cytoscape software identified hub genes with the two topological analysis methods maximal clique centrality and Degree algorithm to construct a miRNA-hub gene network. A total of 1,063 DE-mRNAs were identified between acute KD and healthy individuals, 472 upregulated and 591 downregulated. The constructed PPI network with these DE-mRNAs identified 38 hub genes mostly enriched in pathways related to systemic lupus erythematosus, alcoholism, viral carcinogenesis, osteoclast differentiation, adipocytokine signaling pathway and tumor necrosis factor signaling pathway. Target genes were predicted for the up-regulated and down-regulated DE-miRNAs, 10,203, and 5,310, respectively. Subsequently, 355, and 130 overlapping target DE-mRNAs were obtained for upregulated and downregulated DE-miRNAs, respectively. PPI networks with these target DE-mRNAs produced 15 hub genes, six down-regulated and nine upregulated hub genes. Among these, ten genes (ATM, MDC1, CD59, CD177, TRPM2, FCAR, TSPAN14, LILRB2, SIRPA, and STAT3) were identified as hub genes in the PPI network of DE-mRNAs. Finally, we constructed the regulatory network of DE-miRNAs and hub genes, which suggested potential modulation of most hub genes by hsa-miR-4443 and hsa-miR-6510-5p. SP1 was predicted to potentially regulate most of DE-miRNAs. In conclusion, several hub genes are associated with acute KD. An miRNA–mRNA regulatory network potentially relevant for acute KD pathogenesis provides new insights into the underlying molecular mechanisms of acute KD. The latter may contribute to the diagnosis and treatment of acute KD.

Altered Monocyte Subsets in Kawasaki Disease Revealed by Single-cell RNA-Sequencing

Background

Kawasaki disease (KD) is characterized by a disorder of immune response, and its etiology remains unknown. Monocyte is an important member of the body’s innate immune system; however its role in KD is still elusive due to its ambiguous heterogeneity and complex functions. We aim to comprehensively delineate monocyte heterogeneity in healthy and KD infants and to reveal the underlying mechanism for KD.

Methods

Peripheral monocytes were enriched from peripheral blood samples of two healthy infants and two KD infants. scRNA-seq was performed to acquire the transcriptomic atlas of monocytes. Bio-information analysis was utilized to identify monocyte subsets and explore their functions and differentiation states. SELL+CD14+CD16- monocytes were validated using flow cytometry.

Results

Three monocyte subsets were identified in healthy infants, including CD14+CD16- monocytes, CD14+CD16+ monocytes, and CD14^LowCD16+ monocytes. Cell trajectory analysis revealed that the three monocyte subsets represent a linear differentiation, and possess different biological functions. Furthermore, SELL+CD14+CD16- monocytes, which were poorly differentiated and relating to neutrophil activation, were found to be expanded in KD.

Conclusion

Our findings provide a valuable resource for deciphering the monocyte heterogeneity in healthy infants and uncover the altered monocyte subsets in KD patients, suggesting potential biomarkers for KD diagnosis and treatment.

Crucial transcripts predict response to initial immunoglobulin treatment in acute Kawasaki disease

Although intravenous immunoglobulin (IVIG) can effectively treat Kawasaki disease (KD), 10–20% of KD patients show no beneficial clinical response. Developing reliable criteria to discriminate non-responders is important for early planning of appropriate regimens. To predict the non-responders before IVIG treatment, gene expression dataset of 110 responders and 61 non-responders was obtained from Gene Expression Omnibus. After weighted gene co-expression network analysis, we found that modules positively correlated with the non-responders were mainly associated with myeloid cell activation. Transcripts up-regulated in the non-responders, IL1R2, GK, HK3, C5orf32, CXCL16, NAMPT and EMILIN2, were proven to play key roles via interaction with other transcripts in co-expression network. The crucial transcripts may affect the clinical response to IVIG treatment in acute KD. And these transcripts may serve as biomarkers and therapeutic targets for precise diagnosis and treatment of the non-responders.

Kawasaki Disease and Multisystem Inflammatory Syndrome in Children with COVID-19

Since December 2019, the world has been exposed to a novel virus from the coronaviruses family, named coronavirus disease 2019 (COVID-19), which has affected the life of millions people around the world. This global pandemic causes a wide spectrum of clinical manifestation in children, adults, and elderly. One side of the spectrum in children is being asymptomatic and the other side is severe inflammatory symptoms. In this article, we describe the clinical manifestations, genetic background, and immune response of children with COVID-19, who are presented with severe multisystem inflammatory syndrome (MIS).

The Expression of Glycoprotein Genes in the Inflammatory Process of Kawasaki Disease

Background: Kawasaki disease (KD) is the most common form of febrile coronary vasculitis disease to occur in children. Early diagnosis and proper therapy can prevent the complication of coronary artery lesions (CAL). The main pathogenesis of KD is an inflammatory process related to the host's genetic characteristics. In innate human immunity, the interaction of leukocytes and glycoprotein plays an important role against microbes. The purpose of our study was to understand the role of leukocytes' glycoprotein genes during the acute phase of KD. Materials and Methods: We enrolled a total of 97 subjects from a medical center. Of those, 24 subjects were healthy controls, and 24 subjects were fever controls; the other 49 subjects were KD patients who had had blood samples taken both before and after IVIG treatment. We collected the total RNA from leukocytes and performed a quantitative polymerase chain reaction for the HP, GRP84, and CLEC4D genes in real time. Results: Compared with both the healthy and fever controls, the upregulation of HP, GRP84, and CLEC4D genes was significant in peripheral leukocytes during acute-phase KD. The transcriptional level of these respective genes not only demonstrated a positive correlation with each other, but were also effective predictors for KD (all auROC >0.87) according to the ROC curve analysis. The hyper-expression of these three genes was significantly associated with IVIG resistance, but not CAL formation. Conclusions: Our study demonstrates that the expression of HP, GRP84, and CLEC4D genes of leukocytes play an important role in the pathogenesis and primary IVIG response during the acute inflammatory process of KD.

Kidney injury enhances renal G-CSF expression and modulates granulopoiesis and human neutrophil CD177 in vivo

Kidney injury significantly increases overall mortality. Neutrophilic granulocytes (neutrophils) are the most abundant human blood leukocytes. They are characterized by a high turnover rate, chiefly controlled by granulocyte colony stimulating factor (G‐CSF). The role of kidney injury and uremia in regulation of granulopoiesis has not been reported. Kidney transplantation, which inherently causes ischemia–reperfusion injury of the graft, elevated human neutrophil expression of the surface glycoprotein CD177. CD177 is among the most G‐CSF‐responsive neutrophil genes and reversibly increased on neutrophils of healthy donors who received recombinant G‐CSF. In kidney graft recipients, a transient rise in neutrophil CD177 correlated with renal tubular epithelial G‐CSF expression. In contrast, CD177 was unaltered in patients with chronic renal impairment and independent of renal replacement therapy. Under controlled conditions of experimental ischemia–reperfusion and unilateral ureteral obstruction injuries in mice, renal G‐CSF mRNA and protein expression significantly increased and systemic neutrophilia developed. Human renal tubular epithelial cell G‐CSF expression was promoted by hypoxia and proinflammatory cytokine interleukin 17A in vitro. Clinically, recipients of ABO blood group‐incompatible kidney grafts developed a larger rise in neutrophil CD177. Their grafts are characterized by complement C4d deposition on the renal endothelium, even in the absence of rejection. Indeed, complement activation, but not hypoxia, induced primary human endothelial cell G‐CSF expression. Our data demonstrate that kidney injury induces renal G‐CSF expression and modulates granulopoiesis. They delineate differential G‐CSF regulation in renal epithelium and endothelium. Altered granulopoiesis may contribute to the systemic impact of kidney injury.