The roles of Ca2+/NFAT signaling genes in Kawasaki disease: single- and multiple-risk genetic variants

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.

Novel role for linear ubiquitination in regulating NFAT1 stability

Linear ubiquitination is an important post-translational modification regulating the activation of numerous proinflammatory signalling mediators. Deregulated linear ubiquitination has been implicated in the pathogenesis of several inflammatory and autoimmune diseases. In this issue, Miao et al. have identified a novel role for linear ubiquitination in the stabilisation of the NFAT1 transcription factor, leading to enhanced NFAT1-mediated gene expression, which might have functional implications in patients with Kawasaki disease.

ITPKC polymorphism (rs7251246 T > C), coronary artery aneurysms, and thrombosis in patients with Kawasaki disease in a Southern Han Chinese population

Objectives

Kawasaki disease (KD) is a commonly acquired pediatric systemic vasculitis disease resulting in coronary artery aneurysm (CAA). The relationship between the ITPKC polymorphism (rs7251246) and the severity and susceptibility to KD in the Han Chinese population in Southern China remains unclear.

Methods

We enrolled 262 children as controls and 221 children with KD (46 [20.8%] with intravenous immunoglobulin resistance and 82 [37.1%] with CAA). The relationship between the ITPKC rs7251246 polymorphism, KD susceptibility, and CAA formation was investigated.

Results

While the ITPKC rs7251246 T>C polymorphism was not significantly associated with KD susceptibility, it was significantly related to the CAA risk in children with KD [CC/CT vs. TT: adjusted odds ratio [OR] 2.089, 95% confidence interval [CI] 1.085-4.020]. Male children with the rs7251246 CT/TT genotype had a significantly lower risk of thrombosis [CT/TT vs. CC: adjusted OR 0.251, 95% CI 0.068-0.923]. Children with KD, especially those with CAA, had significantly downregulated ITPKC mRNA compared to healthy children. ITPKC mRNA levels were lower in children with CAA who developed thrombosis (P=0.039). In children with KD, the CC genotype showed lower mRNA levels of ITPKC (P=0.035).

Conclusion

The ITPKC rs7251246 T>C polymorphism may be a risk factor for CAA and thrombosis in children with KD in the Han Chinese population, likely due to differences in mature mRNA levels caused by interference of RNA splicing. Dual antiplatelet therapy for thrombosis is recommended for male children with the rs7251246 CC genotype.

Evolutionary mechanisms underlying the diversification of nuclear factor of activated T cells across vertebrates

The mechanisms of immunity linked to biological evolution are crucial for understanding animal morphogenesis, organogenesis, and biodiversity. The nuclear factor of activated T cells (NFAT) family consists of five members (NFATc1-c4, 5) with different functions in the immune system. However, the evolutionary dynamics of NFATs in vertebrates has not been explored. Herein, we investigated the origin and mechanisms underlying the diversification of NFATs by comparing the gene, transcript and protein sequences, and chromosome information. We defined an ancestral origin of NFATs during the bilaterian development, dated approximately 650 million years ago, where NFAT5 and NFATc1-c4 were derived independently. The conserved parallel evolution of NFATs in multiple species was probably attributed to their innate nature. Conversely, frequent gene duplications and chromosomal rearrangements in the recently evolved taxa have suggested their roles in the adaptive immune evolution. A significant correlation was observed between the chromosome rearrangements with gene duplications and the structural fixation changes in vertebrate NFATs, suggesting their role in NFAT diversification. Remarkably, a conserved gene structure around NFAT genes with vertebrate evolutionary-related breaking points indicated the inheritance of NFATs with their neighboring genes as a unit. The close relationship between NFAT diversification and vertebrate immune evolution was suggested.

MicroRNAs in Kawasaki disease: An update on diagnosis, therapy and monitoring

Kawasaki disease (KD) is an acute autoimmune vascular disease featured with a long stage of febrile. It predominantly afflicts children under 5 years old and causes an increased risk of cardiovascular combinations. The onset and progression of KD are impacted by many aspects, including genetic susceptibility, infection, and immunity. In recent years, many studies revealed that miRNAs, a novel class of small non-coding RNAs, may play an indispensable role in the development of KD via differential expression and participation in the central pathogenesis of KD comprise of the modulation of immunity, inflammatory response and vascular dysregulation. Although specific diagnose criteria remains unclear up to date, accumulating clinical evidence indicated that miRNAs, as small molecules, could serve as potential diagnostic biomarkers and exhibit extraordinary specificity and sensitivity. Besides, miRNAs have gained attention in affecting therapies for Kawasaki disease and providing new insights into personalized treatment. Through consanguineous coordination with classical therapies, miRNAs could overcome the inevitable drug-resistance and poor prognosis problem in a novel point of view. In this review, we systematically reviewed the existing literature and summarized those findings to analyze the latest mechanism to explore the role of miRNAs in the treatment of KD from basic and clinical aspects retrospectively. Our discussion helps to better understand the pathogenesis of KD and may offer profound inspiration on KD diagnosis, treatment, and prognosis.

Association of ITPKC gene polymorphisms rs28493229 and rs2290692 in North Indian children with Kawasaki disease

BACKGROUND

Single-nucleotide polymorphisms (SNPs) of several genes are linked to the etiopathogenesis of Kawasaki disease (KD). Association of SNPs of inositol 1,4,5-triphosphate-3-kinase C (ITPKC) gene with susceptibility to KD and coronary artery lesions (CALs) has been observed in children of certain ethnicities, but not from others. The present study was planned to explore this genetic association in the North Indian cohort.

METHODS

Fifty children with KD and 50 age- and sex-matched controls were studied for two SNPs (rs28493229 and rs2290692) of the ITPKC gene using polymerase chain reaction and restriction fragment length polymorphism. Findings were confirmed by Sanger sequencing. A meta-analysis was also carried out for GG and CC genotypes of the SNPs.

RESULTS

There was significant association between KD susceptibility and CG + GG genotype of rs2290692 (p = 0.015, odds ratio = 4.1, 95% confidence interval = 1.38-13.83). None of the single alleles or genotypes of the SNPs of ITPKC were, however, significantly associated with KD susceptibility. A meta-analysis also did not show any significant association of these SNPs to KD susceptibility.

CONCLUSIONS

Our findings suggest that ITPKC gene SNPs (rs28493229 and rs2290692) did not have a significant association with susceptibility to KD in children from North India. Larger multicentric studies incorporating different ethnicities are required to understand the genetic basis of KD.

IMPACT

While SNP rs28493229 of the ITPKC gene is not found to be associated with susceptibility to KD, the combined genotype of SNP rs2290692 is shown to be associated. Impact of ITPKC gene SNP on KD is different across different races and ethnicities. We could find an association of the combined genotype of rs2290692 with it in the Indian population. This study highlights that phenotype and genotypic association of KD varies with ethnicities. Larger multicentric studies are required to reach a conclusion regarding the genetic association of KD.

The role of Ca2+/NFAT in Dysfunction and Inflammation of Human Coronary Endothelial Cells induced by Sera from patients with Kawasaki disease

Ca²⁺/nuclear factor of activated T-cells (Ca²⁺/NFAT) signaling pathway may play a crucial role in the pathogenesis of Kawasaki disease (KD). We investigated the poorly understood Ca²⁺/NFAT regulation of coronary artery endothelial cells and consequent dysfunction in KD pathogenesis. Human coronary artery endothelial cells (HCAECs) stimulated with sera from patients with KD, compared with sera from healthy children, exhibited significant increases in proliferation and angiogenesis, higher levels of NFATc1 and NFATc3 and some inflammatory molecules, and increased nuclear translocation of NFATc1 and NFATc3. HCAECs stimulated with sera from patients with KD treated with cyclosporine A (CsA) showed decreased proliferation, angiogenesis, NFATc1 and inflammatory molecules levels as compared with results for untreated HCAECs. In conclusion, our data reveal that KD sera activate the Ca²⁺/NFAT in HCAECs, leading to dysfunction and inflammation of endothelial cells. CsA has cytoprotective effects by ameliorating endothelial cell homeostasis via Ca²⁺/NFAT.

Biomarkers for Kawasaki Disease: Clinical Utility and the Challenges Ahead

Kawasaki disease (KD) has replaced acute rheumatic fever as the most common cause of acquired heart disease in children in the developed world and is increasingly being recognized from several developing countries. It is a systemic vasculitis with a predilection for coronary arteries. The diagnosis is based on a constellation of clinical findings that appear in a temporal sequence. Quite understandably, this can become a problem in situations wherein the clinical features are not typical. In such situations, it can be very difficult, if not impossible, to arrive at a diagnosis. Several biomarkers have been recognized in children with acute KD but none of these has reasonably high sensitivity and specificity in predicting the course of the illness. A line up of inflammatory, proteomic, gene expression and micro-RNA based biomarkers has been studied in association with KD. The commonly used inflammatory markers e.g. erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and total leucocyte counts (TLC) lack specificity for KD. Proteomic studies are based on the identification of specific proteins in serum, plasma and urine by gel electrophoresis. A host of genetic studies have identified genes associated with KD and some of these genes can predict the course and coronary outcomes in the affected individuals. Most of these tests are in the early stages of their development and some of these can predict the course, propensity to develop coronary artery sequelae, intravenous immunoglobulin (IVIg) resistance and the severity of the illness in a patient. Development of clinical criteria based on these tests will improve our diagnostic acumen and aid in early identification and prevention of cardiovascular complications.

Kawasaki disease: etiopathogenesis and novel treatment strategies

INTRODUCTION

Kawasaki disease is an acute febrile systemic vasculitis that predominantly occurs in children below five years of age. Its etiopathogenesis is still not clear, but it is thought to be a complex interplay of genetic factors, infections and immunity. Areas covered: This review article discusses in detail Kawasaki disease, with particular emphasis on the recent updates on its pathogenesis and upcoming alternate treatment options. Though self-limiting in many cases, it can lead to severe complications like coronary artery aneurysms and thrombo-embolic occlusions, and hence requires early diagnosis and urgent attention to avoid them. Intravenous immunoglobulin (IVIG) with or without aspirin has remained the sole treatment option for these cases, but 10-15% cases develop resistance to this treatment. Expert commentary: There is a need to develop additional treatment strategies for children with Kawasaki disease. Targeting different steps of pathogenesis could provide us with alternate therapeutic options.

The Emerging Roles of the Calcineurin-Nuclear Factor of Activated T-Lymphocytes Pathway in Nervous System Functions and Diseases

The ongoing epidemics of metabolic diseases and increase in the older population have increased the incidences of neurodegenerative diseases. Evidence from murine and cell line models has implicated calcineurin-nuclear factor of activated T-lymphocytes (NFAT) signaling pathway, a Ca²⁺/calmodulin-dependent major proinflammatory pathway, in the pathogenesis of these diseases. Neurotoxins such as amyloid-β, tau protein, and α-synuclein trigger abnormal calcineurin/NFAT signaling activities. Additionally increased activities of endogenous regulators of calcineurin like plasma membrane Ca²⁺-ATPase (PMCA) and regulator of calcineurin 1 (RCAN1) also cause neuronal and glial loss and related functional alterations, in neurodegenerative diseases, psychotic disorders, epilepsy, and traumatic brain and spinal cord injuries. Treatment with calcineurin/NFAT inhibitors induces some degree of neuroprotection and decreased reactive gliosis in the central and peripheral nervous system. In this paper, we summarize and discuss the current understanding of the roles of calcineurin/NFAT signaling in physiology and pathologies of the adult and developing nervous system, with an emphasis on recent reports and cutting-edge findings. Calcineurin/NFAT signaling is known for its critical roles in the developing and adult nervous system. Its role in physiological and pathological processes is still controversial. However, available data suggest that its beneficial and detrimental effects are context-dependent. In view of recent reports calcineurin/NFAT signaling is likely to serve as a potential therapeutic target for neurodegenerative diseases and conditions. This review further highlights the need to characterize better all factors determining the outcome of calcineurin/NFAT signaling in diseases and the downstream targets mediating the beneficial and detrimental effects.

Genome-Wide Association Study Identifies Novel Susceptibility Genes Associated with Coronary Artery Aneurysm Formation in Kawasaki Disease

Kawasaki disease (KD) or Kawasaki syndrome is known as a vasculitis of small to medium-sized vessels, and coronary arteries are predominantly involved in childhood. Generally, 20–25% of untreated with IVIG and 3–5% of treated KD patients have been developed coronary artery lesions (CALs), such as dilatation and aneurysm. Understanding how coronary artery aneurysms (CAAs) are established and maintained in KD patients is therefore of great importance. Upon our previous genotyping data of 157 valid KD subjects, a genome-wide association study (GWAS) has been conducted among 11 (7%) CAA-developed KD patients to reveal five significant genetic variants passed pre-defined thresholds and resulted in two novel susceptibility protein-coding genes, which are NEBL (rs16921209 (P = 7.44 × 10⁻⁹; OR = 32.22) and rs7922552 (P = 8.43 × 10⁻⁹; OR = 32.0)) and TUBA3C (rs17076896 (P = 8.04 × 10⁻⁹; OR = 21.03)). Their known functions have been reported to associate with cardiac muscle and tubulin, respectively. As a result, this might imply their putative roles of establishing CAAs during KD progression. Additionally, various model analyses have been utilized to determine dominant and recessive inheritance patterns of identified susceptibility mutations. Finally, all susceptibility genes hit by significant genetic variants were further investigated and the top three representative gene-ontology (GO) clusters were regulation of cell projection organization, neuron recognition, and peptidyl-threonine phosphorylation. Our results help to depict the potential routes of the pathogenesis of CAAs in KD patients and will facilitate researchers to improve the diagnosis and prognosis of KD in personalized medicine.

New challenges and promises in solid organ transplantation pharmacogenetics: the genetic variability of proteins involved in the pharmacodynamics of immunosuppressive drugs

Interindividual variability in immunosuppressive drug responses might be partly explained by genetic variants in proteins involved in the immune response or associated with IS pharmacodynamics. On a general basis, the pharmacogenetics of drug target proteins is less known and understood than that of proteins involved in drug disposition pathways. The aim of this review is to facilitate research related to the pharmacodynamics of the main immunosuppressive drugs used in solid organ transplantation. We elaborated a quality of evidence grading system based on a literature review and identified 'highly recommended', 'recommended' or 'potential' candidates for further research. It is likely that a number of additional rare variants might further explain drug response phenotypes in transplantation, and particularly the most severe ones. The advent of next-generation sequencing will help to identify those variants.