Single-Cell Transcriptome Reveals Potential Mechanisms for Coronary Artery Lesions in Kawasaki Disease.

BACKGROUND: Coronary artery lesions (CALs) are the most common and major complication of Kawasaki disease (KD) in developed countries. However, the underlying immunologic mechanisms of CAL development in KD remain unclear. METHODS: Here, we conducted single-cell transcriptome analyses of 212 210 peripheral blood mononuclear cells collected from a cross-sectional cohort of 16 children, including 4 patients with KD with CALs, 5 patients with KD without CALs, 4 healthy controls, and 3 febrile controls. RESULTS: KD altered the proportion of peripheral blood mononuclear cells, including an increasing trend in inflammatory cells (megakaryocytes and monocytes) and a decreasing trend in lymphocytes (eg, CD4+ T, CD8+ T, mucosal-associated invariant T, natural killer, and γδ T cells), highlighting the potential presence of lymphopenia phenomenon in KD. Our data indicated the presence of inflammatory cytokine storm in patients with KD with CALs, caused by systemic upregulation of TNFSF13B (tumor necrosis factor superfamily member 13b), CXCL16 (C-X-C motif chemokine ligand 16), TNFSF10 (tumor necrosis factor superfamily member 10), and IL1RN (interleukin 1 receptor antagonist), mainly produced by monocytes (especially for the Mono_CD14-CD16 cluster) and megakaryocytes. We also found that myeloid cells of patients with KD, particularly in those with CALs, might play a role in vascular injury (eg, increased MMP [matrix metalloproteinase] 9, MMP17, and MMP25) and immune cell recruitment. The immune landscape of patients with KD with CALs was featured by lower exhaustion levels in natural killer cells, a high cytotoxic state in the CD8_Pro cluster, and activation of the complement system in monocytes. Additionally, the activation of B cells was more pronounced in the early stage of KD. CONCLUSIONS: Collectively, this study provides a comprehensive understanding of the roles of various immune cells and inflammatory cytokine storms in the development of CALs in KD and offers a valuable resource for identifying novel therapeutic targets for patients with KD with CALs.

Single-Cell Meta-Analysis of Neutrophil Activation in Kawasaki Disease and Multisystem Inflammatory Syndrome in Children Reveals Potential Shared Immunological Drivers.

BACKGROUND: Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) share similar clinical manifestations, including cardiovascular complications, suggesting similar underlying immunopathogenic processes. Aberrant neutrophil activation may play a crucial role in the shared pathologies of KD and MIS-C; however, the associated pathogenic mechanisms and molecular drivers remain unknown. METHODS: We performed a single-cell meta-analysis of neutrophil activation with 103 pediatric single-cell transcriptomic peripheral blood mononuclear cell data across 9 cohorts, including healthy controls, KD, MIS-C, compared with dengue virus infection, juvenile idiopathic arthritis, and pediatric celiac disease. We used a series of computational analyses to investigate the shared neutrophil transcriptional programs of KD and MIS-C that are linked to systemic damage and cardiac pathologies, and suggested Food and Drug Administration-approved drugs to consider as KD and MIS-C treatment. RESULTS: We meta-analyzed 521 950 high-quality cells. We found that blood signatures associated with risks of cardiovascular events are enriched in neutrophils of KD and MIS-C. We revealed the expansion of CD177+ neutrophils harboring hyperactivated effector functions in both KD and MIS-C, but not in healthy controls or in other viral-, inflammatory-, or immune-related pediatric diseases. KD and MIS-C CD177+ neutrophils had highly similar transcriptomes, marked by conserved signatures and pathways related to molecular damage. We found the induction of a shared neutrophil expression program, potentially regulated by SPI1 (Spi-1 proto-oncogene), which confers enhanced effector functions, especially neutrophil degranulation. CD177 and shared neutrophil expression program expressions were associated with acute stages and attenuated during KD intravenous immunoglobulin treatment and MIS-C recovery. Network analysis identified hub genes that correlated with the high activation of CD177+ neutrophils. Disease-gene association analysis revealed that the KD and MIS-C CD177+ neutrophils' shared expression program was associated with the development of coronary and myocardial disorders. Last, we identified and validated TSPO (translocator protein) and S100A12 (S100 calcium-binding protein A12) as main molecular targets, for which the Food and Drug Administration-approved drugs methotrexate, zaleplon, metronidazole, lorazepam, clonazepam, temazepam, and zolpidem, among others, are primary candidates for drug repurposing. CONCLUSIONS: Our findings indicate that CD177+ neutrophils may exert systemic pathological damage contributing to the shared morbidities in KD and MIS-C. We uncovered potential regulatory drivers of CD177+ neutrophil hyperactivation and pathogenicity that may be targeted as a single therapeutic strategy for either KD or MIS-C.

The activation of CaN/NFAT signaling pathway in macrophages aggravated Lactobacillus casei cell wall extract-induced Kawasaki disease vasculitis.

OBJECTIVES: By using GWAS(genome-wide association studies) and linkage disequilibrium analysis to investigate the susceptibility genes of KD(Kawasaki disease), previous studies have identified that the CaN(calcineurin)-NFAT(the nuclear factor of activated T cell) signal pathway were significantly associated with susceptibility to KD. However, little is known about the molecular basis of the CaN/NFAT pathway involved in KD. Therefore, in our study we investigate the role of Ca2+/CaN/NFAT signaling pathway in macrophages in vitro and in vivo on coronary artery lesions induced by LCWE (Lactobacillus casei cell wall extract). METHODS AND RESULTS: We observed that LCWE could increase the expression of NFAT1 and NFAT2 in macrophages in vitro, and also enhance the transcriptional activity of NFAT by promoting the nucleus translocation. Similarly, in LCWE-induced mice model, the expression of NFAT1 and NFAT2 and associated proinflammatory factors were increased significantly. In addition, by knocking down or overexpressing NFAT1 or NFAT2 in macrophages, the results indicated that NFAT signaling pathway mediated LCWE-induced immune responses in macrophages and regulated the synthesis of IL(interleukin)-6, IL-1ß and TNF(tumor necrosis factor)-α in LCWE-induced macrophage activation. As well, we found that this process could be suppressed by CaN inhibitor CsA(cyclosporinA). CONCLUSIONS: Therefore, the CaN/NFAT signaling pathway mediated LCWE-induced immune responses in macrophages, and also participated in the LCWE-induced CALs(coronary artery lesions). And also the inhibitory effect of CsA in LCWE-induced cell model towards a strategy to modulate the CaN/NFAT pathway during the acute course of KD might be helpful in alleviate KD-induced CALs.

MiR-223-3p affects the proliferation and apoptosis of HCAECs in Kawasaki disease by regulating the expression of FOXP3.

OBJECTIVE: Kawasaki disease (KD) can lead to permanent damage to coronary structures, the pathogenesis of which remains unknown. This experiment was designed to investigate whether miR-223-3p secreted in the serum of KD patients affects the proliferation and apoptosis of HCAECs in KD by regulating FOXP3. METHODS: Blood samples were collected in acute febrile phase of KD, after IVIG treatment, and from healthy controls. Transfected into HCAECs cells by synthetic FOXP3 siRNA/NC. A co-culture system was established between HCAECs cells transfected with FOXP3 siRNA/NC and THP1 cells added with three sera. RESULTS: Compared with the control group, the expressions of miR-223-3p, RORγt, and Th17 in serum of KD patients were significantly upregulated, and the expressions of TGF-ß1, FOXP3 and Treg were significantly downregulated. At the same time, the levels of IL-6, IL-17, and IL-23 were significantly increased, and the levels of IL-10 and FOXP3 were significantly decreased. After IVIG treatment, the patient's above results were reversed. The serum of KD patients increased the expression of miR-223-3p and inhibited the expression of FOXP3 in HCAECs cells. IVIG serum is the opposite. Overexpression of miR-223-3p also promoted the apoptosis of HCAECs. In addition, serum from KD patients promoted apoptosis, whereas serum after IVIG treatment inhibited apoptosis. KD patient serum downregulated the expression of FOXP3, Bcl2, TGF-ß1 and IL-10 in cells, and upregulated the expression of caspase3, Bax, IL-17, IL-6, and IL-23. The opposite results were obtained with IVIG-treated sera. CONCLUSION: miR-223-3p secreted in serum of KD patients can regulate the expression of FOXP3 and affect the proliferation, apoptosis, and inflammation of cells.

Upregulation of miR-184 and miR-19a-3p induces endothelial dysfunction by targeting AGO2 in Kawasaki disease.

BACKGROUND: Endothelial dysfunction is a marked feature of Kawasaki disease during convalescence, but its pathogenesis is currently unclear. Circulating microRNAs (miRNAs) are associated with the progression of Kawasaki disease. However, the role and mechanism of circulating miRNAs in endothelial dysfunction are largely unknown. Kawasaki disease patients were found to have a unique circulating miRNA profile, including upregulation of miRNA-210-3p, miR-184 and miR-19a-3p, compared to non-Kawasaki disease febrile controls. This study aimed to investigate the effects of these three miRNAs on endothelial function. METHODS: Overexpression of miRNAs in human umbilical vein endothelial cells was done by transfection of miRNA mimics. The tube formation assay was used to evaluate the function of human umbilical vein endothelial cells. The potential binding sites of miRNAs on 3'untranslated regions were predicted by using TargetScan database and validated by dual luciferase reporter assay. The protein expression of AGO2, PTEN and VEGF in human umbilical vein endothelial cells was detected by Western blot. Overexpression of AGO2 in human umbilical vein endothelial cells was done by transfection of AGO2 expression plasmids. RESULTS: Overexpression of miRNA-184 and miRNA-19a-3p, but not miR-210-3p, impaired the function of human umbilical vein endothelial cells. Mechanistically, miR-184 and miR-19a-3p could target the 3'untranslated regions of AGO2 mRNA to downregulate its expression and subsequently impede the AGO2/PTEN/VEGF axis. To be noted, the rescue of the expression of AGO2 remarkably recovered the function that was impaired by overexpression of miRNA-184 and miRNA-19a-3p. CONCLUSIONS: This study suggested that miR-184 and miR-19a-3p could target AGO2/PTEN/VEGF axis to induce endothelial dysfunction in Kawasaki disease.

RNA Sequencing Reveals Beneficial Effects of Atorvastatin on Endothelial Cells in Acute Kawasaki Disease.

Background Damage to the coronary arteries during the acute phase of Kawasaki disease (KD) is linked to inflammatory cell infiltration, myointimal proliferation, and endothelial cell (EC) dysfunction. To understand the response of ECs to KD treatment, we studied the genome-wide transcriptional changes in cultured ECs incubated with KD sera before and after treatment with or without atorvastatin. Methods and Results RNA sequencing of human umbilical vein ECs incubated with pooled sera from patients with acute KD before or after treatment with intravenous immunoglobulin and infliximab revealed differentially expressed genes in interleukin-1, tumor necrosis factor-α, and inflammatory cell recruitment pathways. Subacute sera pooled from patients treated with intravenous immunoglobulin, infliximab, and atorvastatin uniquely induced expression of NOS3, Kruppel like factor (KLF2, and KLF4 (promotes EC homeostasis and angiogenesis) and ZFP36 ring finger protein (ZFP36) and suppressor of cytokine signaling 3 (SOCS3) (suppresses inflammation), and suppressed expression of TGFB2 and DKK1 (induces endothelial-mesenchymal transition) and sphingosine kinase 1 (SPHK1) and C-X-C motif chemokine ligand 8 (CXCL8) (induces inflammation). Conclusions These results suggest that atorvastatin treatment of patients with acute KD may improve EC health, reduce mediators of inflammation produced by ECs, and block KD-induced myofibroblast proliferation.

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.

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.

Severe delayed hypersensitivity reactions to IL-1 and IL-6 inhibitors link to common HLA-DRB1*15 alleles.

OBJECTIVES: Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe, delayed hypersensitivity reaction (DHR). We observed DRESS to inhibitors of interleukin 1 (IL-1) or IL-6 in a small group of patients with Still's disease with atypical lung disease. We sought to characterise features of patients with Still's disease with DRESS compared with drug-tolerant Still's controls. We analysed human leucocyte antigen (HLA) alleles for association to inhibitor-related DHR, including in a small Kawasaki disease (KD) cohort. METHODS: In a case/control study, we collected a multicentre series of patients with Still's disease with features of inhibitor-related DRESS (n=66) and drug-tolerant Still's controls (n=65). We retrospectively analysed clinical data from all Still's subjects and typed 94/131 for HLA. European Still's-DRESS cases were ancestry matched to International Childhood Arthritis Genetics Consortium paediatric Still's cases (n=550) and compared for HLA allele frequencies. HLA association also was analysed using Still's-DRESS cases (n=64) compared with drug-tolerant Still's controls (n=30). KD subjects (n=19) were similarly studied. RESULTS: Still's-DRESS features included eosinophilia (89%), AST-ALT elevation (75%) and non-evanescent rash (95%; 88% involving face). Macrophage activation syndrome during treatment was frequent in Still's-DRESS (64%) versus drug-tolerant Still's (3%; p=1.2×10-14). We found striking enrichment for HLA-DRB1*15 haplotypes in Still's-DRESS cases versus INCHARGE Still's controls (p=7.5×10-13) and versus self-identified, ancestry-matched Still's controls (p=6.3×10-10). In the KD cohort, DRB1*15:01 was present only in those with suspected anakinra reactions. CONCLUSIONS: DRESS-type reactions occur among patients treated with IL-1/IL-6 inhibitors and strongly associate with common HLA-DRB1*15 haplotypes. Consideration of preprescription HLA typing and vigilance for serious reactions to these drugs are warranted.

CASP5 and CR1 as potential biomarkers for Kawasaki disease: an Integrated Bioinformatics-Experimental Study.

BACKGROUND: Kawasaki disease (KD) is a pediatric inflammatory disorder causes coronary artery complications. The disease overlapping manifestations with a set of symptomatically like diseases such as bacterial and viral infections, juvenile idiopathic arthritis, Henoch-Schönlein purpura, infection of unknown etiology, group-A streptococcal and adenoviral infections, and incomplete KD could lead to misdiagnosis of the disease. METHODS: In the present study, we applied weighted gene co-expression network analysis (WGCNA) to identify network modules of co-expressed genes in GSE73464 and also, limma package was used to identify the differentially expressed genes (DEGs) in KD expression arrays composed of GSE73464, GSE18606, GSE109351, and GSE68004. By merging the results of WGCNA and limma, we detected hub genes. Then, analyzed the peripheral blood mononuclear cells (PBMCs) of 16 patients and 8 control subjects using Real-Time Polymerase Chain Reaction (RT-PCR) to evaluate the previous results. RESULTS: We assessed the diagnostic potency of the screened genes by plotting the area under curve (AUC). We finally identified 2 genes CASP5(Caspase 5) and CR1(Complement C3b/C4b Receptor 1) which were shown to potentially discriminate KD from other similar diseases and also from healthy people. CONCLUSIONS: The results of RT-PCR and AUC confirmed the diagnostic potentials of two suggested biomarkers for KD.

SARS-CoV-2-related MIS-C: A key to the viral and genetic causes of Kawasaki disease?

Multisystem inflammatory syndrome in children (MIS-C) emerged in April 2020 in communities with high COVID-19 rates. This new condition is heterogenous but resembles Kawasaki disease (KD), a well-known but poorly understood and clinically heterogenous pediatric inflammatory condition for which weak associations have been found with a myriad of viral illnesses. Epidemiological data clearly indicate that SARS-CoV-2 is the trigger for MIS-C, which typically occurs about 1 mo after infection. These findings support the hypothesis of viral triggers for the various forms of classic KD. We further suggest that rare inborn errors of immunity (IEIs) altering the immune response to SARS-CoV-2 may underlie the pathogenesis of MIS-C in some children. The discovery of monogenic IEIs underlying MIS-C would shed light on its pathogenesis, paving the way for a new genetic approach to classic KD, revisited as a heterogeneous collection of IEIs to viruses.

Effect of Activin A on activation status of monocytes in acute-phase Kawasaki disease.

Kawasaki disease is a kind of self-limited systemic vasculitis involving middle and small arteries, which usually occurs in children under 5 years old. Excessive inflammatory response caused by activation of monocytes is one of the important mechanisms of Kawasaki disease. Activated monocytes secrete large amounts of inflammatory mediators such as TNF-α and IL-1ß. Activin A, a member of transforming growth factor-ß superfamily, is a multifunctional growth and transforming factor. Several experimental evidences pinpoint that Activin A can regulate multiple biological function of the immune system. However, whether Activin A is involved in regulation of activation of monocytes in Kawasaki disease was not well characterized. Here, this study showed that the expression of Activin A in serum decreased in acute-phase Kawasaki disease. Furthermore, Activin A inhibits activin type IIA receptor, activin type IB receptor, CD86 and CD80 expression in over-activated monocytes. In addition, Activin A inhibited Smad3 expression and NF-κB signaling pathways. Specific function and mechanism of Activin A in acute-phase Kawasaki disease need further study.

Association of TNF-α rs1800629, CASP3 rs72689236 and FCGR2A rs1801274 Polymorphisms with Susceptibility to Kawasaki Disease: A Comprehensive Meta-Analysis.

BACKGROUND: Kawasaki Disease (KD) is a multifactorial condition at the junction of infectious diseases, immunology, rheumatology, and cardiology. The aim of this study is to derive a more precise estimation of the association of TNF-α rs1800629, CASP3 rs72689236 and FCGR2A rs1801274 polymorphisms with risk of KD. Methods: PubMed, EMBASE, CNKI databases were searched to identify all relevant studies. Pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated using CMA 2.2 software. Results: A total of 25 studies including eleven studies on TNF-α rs1800629, five studies on CASP3 rs72689236 and nine studies on FCGR2A rs1801274 were selected. Overall, pooled data revealed that CASP3 rs72689236 and FCGR2A rs1801274 polymorphisms were significantly associated with an increased risk of KD. However, there was no significant association between TNF-α rs1800629 and KD. Conclusions: This meta-analysis suggested that CASPS rs72689236 and FCGR2A rs1801274 polymorphisms may modulate individual susceptibility to KD.

Functional benefits of corticosteroid and IVIG combination therapy in a coronary artery endothelial cell model of Kawasaki disease.

BACKGROUND: Kawasaki disease (KD) is the most common pediatric systemic vasculitides of unknown etiology. Recent clinical studies led to reappraisal of the usefulness of initial combination therapy of intravenous immunoglobulin (IVIG) plus a corticosteroid for patients with severe KD. However, the molecular mechanisms underlying the clinical benefits of that combination therapy remain unclear. Here, we used cultured human coronary artery endothelial cells (HCAECs), as a mimic of KD, to study the possible mechanisms responsible for the clinical benefits of adding a corticosteroid to standard IVIG therapy for patients with severe KD. METHODS: HCAECs were stimulated with TNF-α, IL-1α or IL-1ß in the presence and absence of high-dose IgG and/or dexamethasone (DEX). The mRNA and protein concentrations for high-mobility group box-1 (HMGB1), IL-1α, IL-6 and granulocyte-colony stimulating factor (G-CSF) in the culture supernatants were measured by quantitative PCR (qPCR) and ELISA, respectively. Apoptosis was evaluated by the caspase 3/7 activities. RESULTS: DEX, but not IgG, significantly inhibited apoptosis caused by inflammatory stimuli, resulting in effective reduction of HMGB1 and IL-1α protein release by HCAECs. As previously reported, DEX or IgG alone significantly suppressed TNF-α-induced production of IL-6 and G-CSF and mRNA expression, but induction of those cytokines by IL-1 s (IL-1α and IL-1ß) was resistant to high-dose IgG. CONCLUSIONS: A corticosteroid can effectively inhibit the release of HMGB1 and IL-1α, which may be involved in IVIG resistance in KD. Since high-dose IgG does not have such beneficial anti-cytotoxic effects, adding a corticosteroid to standard IVIG therapy may help prevent the progression of IVIG resistance in KD.

The Platelet microRNA Profile of Kawasaki Disease: Identification of Novel Diagnostic Biomarkers.

Challenging diagnosis and unknown etiology of Kawasaki disease (KD) increase the coronary artery lesions incidence. microRNAs (miRNAs) are the most promising biomarkers because of their stability in peripheral blood and noninvasive measurement procedure, whose potential utility have been proved in cancers. To explore the utility of differentially expressed (DE) miRNAs as early diagnostic markers, 44 patients (25 incomplete KD and 19 complete KD) and 31 febrile controls were recruited for small RNA sequencing. From all the 1922 expressed miRNA, 210 DE miRNAs were found between KD and febrile control groups. Though platelet miRNA profiles of complete KD incomplete KD were much similar through cluster analysis, the DE miRNAs were not identical. Eight DE miRNAs were validated by real-time quantitative PCR (qRT-PCR) in complete or incomplete KD groups using a normalizer, miR-126-3p, which was identified by geNorm and NormFinder tools. The expression level of miRNAs continuous changed over time was observed and the function analysis showed the potential role of miRNAs as therapeutic biomarkers. Additionally, the prediction model for KD showed a sensitivity of 78.8% and a specificity of 71.4%, respectively. This study used small RNA sequencing to identify miRNA biomarkers KD diagnosis based on a large sample size. Our findings shine a light on the understanding of molecular pathogenesis of KD and may improve the accuracy of KD diagnosis and prognosis in clinical.

Kawasaki-like disease in children with COVID-19: A hypothesis.

With rapid spread of severe acute respiratory syndrome- corona virus-2 (SARS-COV-2) globally, some new aspects of the disease have been reported. Recently, it has been reported the incidence of Kawasaki-like disease among children with COVID-19. Since, children had been known to be less severely affected by the virus in part due to the higher concentration of Angiotensin converting enzyme (ACE)-2 receptor, this presentation has emerged concerns regarding the infection of children with SARS-COV2. ACE2 has anti-inflammatory, anti-fibrotic and anti-proliferative characteristics through converting angiotensin (Ag)-II to Ang (1-7). ACE2 receptor is downregulated by the SARS-COV through the spike protein of SARS-CoV (SARS-S) via a process that is tightly coupled with Tumor necrosis factor (TNF)-α production. TNF-α plays a key role in aneurysmal formation of coronary arteries in Kawasaki disease (KD). Affected children by COVID-19 with genetically-susceptible to KD might have genetically under-expression of ACE2 receptor that might further decrease the expression of ACE2 due to the downregulation of the receptor by the virus in these patients. It appears that TNF- α might be the cause and the consequence of the ACE2 receptor downregulation which results in arterial walls aneurysm. Conclusion: Genetically under-expression of ACE2 receptor in children with genetically-susceptible to KD who are infected with SARS-CoV-2 possibly further downregulates the ACE2 expression by TNF-α and leads to surge of inflammation including TNF-α and progression to Kawasaki-like disease.

Adjuvant herbal therapy for targeting susceptibility genes to Kawasaki disease: An overview of epidemiology, pathogenesis, diagnosis and pharmacological treatment of Kawasaki disease.

BACKGROUND: Kawasaki disease (KD) is a self-limiting acute systemic vasculitis occur mainly in infants and young children under 5 years old. Although the use of acetylsalicylic acid (AAS) in combination with intravenous immunoglobulin (IVIG) remains the standard therapy to KD, the etiology, genetic susceptibility genes and pathogenic factors of KD are still un-elucidated. PURPOSE: Current obstacles in the treatment of KD include the lack of standard clinical and genetic markers for early diagnosis, possible severe side effect of AAS (Reye's syndrome), and the refractory KD cases with resistance to IVIG therapy, therefore, this review has focused on introducing the current advances in the identification of genetic susceptibility genes, environmental factors, diagnostic markers and adjuvant pharmacological intervention for KD. RESULTS: With an overall update in the development of KD from different aspects, our current bioinformatics data has suggested CASP3, CD40 and TLR4 as the possible pathogenic factors or diagnostic markers of KD. Besides, a list of herbal medicines which may work as the adjunct therapy for KD via targeting different proposed molecular targets of KD have also been summarized. CONCLUSION: With the aid of modern pharmacological research and technology, it is anticipated that novel therapeutic remedies, especially active herbal chemicals targeting precise clinical markers of KD could be developed for accurate diagnosis and treatment of the disease.

Hypomethylation of C1q/tumor necrosis factor-related protein-1 promoter region in whole blood and risks for coronary artery aneurysms in Kawasaki disease.

BACKGROUND: Kawasaki disease (KD) is characterized as a self-limited systemic vasculitis. C1q/tumor necrosis factor-related protein-1 (CTRP1) had been associated with the occurrence of vasculitis in KD. Methylation at the promoter region of certain genes was reported to be involved in the development process of KD. This study aims to investigate the methylation levels of CTRP1 in KD, as well as, its potential to predict coronary artery aneurysms (CAAs). METHODS: 31 patients with KD and 14 healthy controls (HCs) were recruited into this study. The KD group was further divided into KD with CAA (KD-CAAs) group and KD without NCAAs (KD-NCAAs) group. Methylation levels of CpG sites were determined by MethylTarget sequencing, a method that uses multiple targeted CpG methylation analysis. RESULTS: The methylation levels of CTRP1 promoter region in the KD group were lower than that in the HC group at all predicted CpG sites, especially at sites 34, 51, 69, 79, 176 and 206. Compared with KD-CAAs group, the methylation levels of almost every CpG sites of CTRP1 were increased in the KD-NCAAs group, with site 69 and 154 found to be strongly related to the occurrence of CAAs. CONCLUSIONS: The difference in methylation levels of CTRP1 promoter may be involved in the development process of KD, and may be a potential predictive marker for the occurrence of CAAs.

Identification of SAMD9L as a susceptibility locus for intravenous immunoglobulin resistance in Kawasaki disease by genome-wide association analysis.

Kawasaki disease (KD) is a systemic vasculitis affecting infants and children; it manifests as fever and signs of mucocutaneous inflammation. Intravenous immunoglobulin (IVIG) treatment effectively attenuates the fever and systemic inflammation. However, 10-20% patients are unresponsive to IVIG. To identify genetic variants influencing IVIG non-response in KD, a genome-wide association study (GWAS) and a replication study were performed using a total of 148 IVIG non-responders and 845 IVIG-responders in a Korean population. rs28662 in the sterile alpha motif domain-containing protein 9-like (SAMD9L) locus showed the most significant result in the joint analysis of GWAS and replication samples (odds ratio (OR) = 3.47, P = 1.39 × 10-5). The same SNP in the SAMD9L locus was tested in the Japanese population, and it revealed a more significant association in a meta-analysis with Japanese data (OR = 4.30, P = 5.30 × 10-6). These results provide new insights into the mechanism of IVIG response in KD.