Single nucleotide polymorphism rs2229634 in the ITPR3 gene is associated with the risk of developing coronary artery aneurysm in children with Kawasaki disease

Cellular Senescence Genes as Cutting-Edge Signatures for Abdominal Aortic Aneurysm Diagnosis: Potential for Innovative Therapeutic Interventions

Abdominal aortic aneurysm (AAA) is the most prevalent dilated arterial aneurysm that poses a significant threat to older adults, but the molecular mechanisms linking senescence to AAA progression remain poorly understood. This study aims to identify cellular senescence-related genes (SRGs) implicated in AAA development and assess their potential as therapeutic targets. Four hundred and twenty-nine differentially expressed genes (DEGs) were identified from the GSE57691 training set, and 867 SRGs were obtained. Through the intersection of DEGs with SRGs, 19 differentially expressed senescence-related genes (DESRGs) were uncovered. Functional enrichment analysis was performed to explore their biological roles in AAA. To identify hub genes, we applied machine learning algorithms, including LASSO, SVM-RFE and random forest. These hub genes were then validated in two independent datasets. In the initial validation cohort, significant differences in the expression levels of BTG2, ETS1, ID1 and ITPR3 were observed between the AAA and control groups. Receiver operating characteristic (ROC) analysis demonstrated a robust diagnostic performance. Further validation across different AAA stages (small, large and ruptured AAA) identified ETS1 and ITPR3 as potential diagnostic genes. Subsequently, the diagnostic relevance of ETS1 and ITPR3 was further validated in human serum samples and mouse models of AAA. In addition, single-cell RNA sequencing suggests that senescent endothelial cells play a pivotal role in AAA progression, we further confirmed the correlation between ETS1 and ITPR3 and senescent endothelial cells by WB, IF and RT-qPCR. In conclusion, our study reveals the pivotal role of cellular senescence in AAA progression and identifies ETS1 and ITPR3 as promising diagnostic biomarkers.

Strong selection signatures for Aleutian disease tolerance acting on novel candidate genes linked to immune and cellular responses in American mink (Neogale vison)

Aleutian disease (AD) is a multi-systemic infectious disease in American mink (Neogale vison) caused by Aleutian mink disease virus (AMDV). This study aimed to identify candidate regions and genes underlying selection for response against AMDV using whole-genome sequence (WGS) data. Three case-control selection signatures studies were conducted between animals (N = 85) producing high versus low antibody levels against AMDV, grouped by counter immunoelectrophoresis (CIEP) test and two enzyme-linked immunosorbent assays (ELISA). Within each study, selection signals were detected using fixation index (FST) and nucleotide diversity (θπ ratios), and validated by cross-population extended haplotype homozygosity (XP-EHH) test. Within- and between-studies overlapping results were then evaluated. Within-studies overlapping results indicated novel candidate genes related to immune and cellular responses (e.g., TAP2, RAB32), respiratory system function (e.g., SPEF2, R3HCC1L), and reproduction system function (e.g., HSF2, CFAP206) in other species. Between-studies overlapping results identified three large segments under strong selection pressure, including two on chromosome 1 (chr1:88,770-98,281 kb and chr1:114,133-120,473) and one on chromosome 6 (chr6:37,953-44,279 kb). Within regions with strong signals, we found novel candidate genes involved in immune and cellular responses (e.g., homologous MHC class II genes, ITPR3, VPS52) in other species. Our study brings new insights into candidate regions and genes controlling AD response.

Type 3 IP3 receptor: Its structure, functions, and related disease implications

Cell-fate decisions depend on the precise and strict regulation of multiple signaling molecules and transcription factors, especially intracellular Ca2+ homeostasis and dynamics. Type 3 inositol 1,4,5-triphosphate receptor (IP3R3) is an a tetrameric channel that can mediate the release of Ca2+ from the endoplasmic reticulum (ER) in response to extracellular stimuli. The gating of IP3R3 is regulated not only by ligands but also by other interacting proteins. To date, extensive research conducted on the basic structure of IP3R3, as well as its regulation by ligands and interacting proteins, has provided novel perspectives on its biological functions and pathogenic mechanisms. This review aims to discuss recent advancements in the study of IP3R3 and provides a comprehensive overview of the relevant literature pertaining to its structure, biological functions, and pathogenic mechanisms.

Transcriptional ITPR3 as potential targets and biomarkers for human pancreatic cancer

Inositol 1,4,5-Triphosphate Receptor Family (ITPRs) are necessary intracellular Ca2+-release channel encoders and participate in mammalian cell physiological and pathological processes. Previous studies have suggested that ITPRs participate in tumorigenesis of multiple cancers. Nevertheless, the diverse expression profiles and prognostic significance of three ITPRs in pancreatic cancer have yet to be uncovered. In this work, we examined the expression levels and survival dates of ITPRs in patients with pancreatic cancer. As a result, we identified that ITPR1 and ITPR3 expression levels are significantly elevated in cancerous specimens. Survival data revealed that over-expression of ITPR2 and ITPR3 resulted in unfavourable overall survival and pathological stage. The multivariate Cox logistic regression analysis showed that ITPR3 could be an independent risk factor for PAAD patient survival. Moreover, to investigate how ITPRs work, co-expressed genes, alterations, protein-protein interaction, immune infiltration, methylation, and functional enrichment of ITPRs were also analyzed. Then, we evaluated these findings in clinical samples. Moreover, the gain and loss of function of ITPR3 were also conducted. The electron microscope assay was employed to explore the role of ITPR3 in pancreatic cancer cell lines' endoplasmic reticulum stress. In summary, our findings demonstrated that ITPR3 has the potential to be drug targets and biomarkers for human pancreatic cancer.

The rs7404339 AA Genotype in CDH5 Contributes to Increased Risks of Kawasaki Disease and Coronary Artery Lesions in a Southern Chinese Child Population

Background

Kawasaki disease (KD) is an acute, self-limited febrile illness of unknown cause. And it predominantly affects children <5 years and the main complication is coronary artery lesion (CAL). Studies demonstrated that vascular endothelial cells (VECs) played a very important role in the CAL of KD. VE-cad encoded by CDH5 may exert a relevant role in endothelial cell biology through controlling the cohesion of the intercellular junctions. The pathogenesis of KD remains unclear and genetic factors may increase susceptibility of KD. However, the relationship between CDH5 polymorphisms and KD susceptibility has not been reported before. The present study is aimed at investigating whether the rs7404339 polymorphism in CDH5 is associated with KD susceptibility and CAL in a southern Chinese child population.

Methods and Results

We recruited 1,335 patients with KD and 1,669 healthy children. Each participant had supplied 2 mL of fresh blood in the clinical biologic bank at our hospital for other studies. Multiplex PCR is used to assess the genotypes of rs7404339 polymorphism in CDH5. According to the results, we found significant correlated relationship between rs7404339 polymorphism in CDH5 and KD susceptibility [AA vs. GG: adjusted odds ratio (OR) = 1.43, 95% confidence interval (CI) = 1.00-2.05; p = 0.0493; recessive model: adjusted OR = 1.44, 95% CI = 1.01-2.06, P = 0.0431]. In further stratified analysis, we found that children younger than 60 months (adjusted OR = 1.46, 95% CI = 1.01-2.10; p = 0.0424) and male (adjusted OR = 1.70, 95% CI = 1.09-2.65; p = 0.0203) with the rs7404339 AA genotype in CDH5 had a higher risk of KD than carriers of the GA/GG genotype. Furthermore, stratification analysis revealed that patients with the rs7404339 AA genotype exhibited the significantly higher onset risk for CAL than carriers of the GA/GG genotype (adjusted age and gender odds ratio = 1.56, 95% CI = 1.01-2.41; P = 0.0433).

Conclusion

Our results showed that rs7404339 AA genotype in CDH5 is significant associated with KD susceptibility. And children younger than 60 months and male with the rs7404339 AA genotype had a higher risk of KD than carriers with the GA/GG genotype. Furthermore, patients with the rs7404339 AA genotype exhibited a significantly higher risk of CAL complication than carriers of the GA/GG genotype.

eQTL Highlights the Potential Role of Negative Control of Innate Immunity in Kawasaki Disease

Purpose

Kawasaki disease (KD) is an acute systemic vasculitis mainly found in the medium-sized arteries, especially the coronary arteries. Immune system is involved in the pathogenesis of acute KD in children, but the functional differences in the immune system between healthy children and KD patients remain unclear.

Patients and Methods

A total of 190 KD patients and 119 healthy controls were recruited for the next-generation sequencing of 512 targeted genes from 4 immune-related pathways. Subsequently, the peripheral blood mononuclear cells (PBMCs) were isolated. RNA sequencing of the LPS treated PBMCs from additional 20 KD patients and 20 healthy controls was used to examine the differentially expressed genes (DEGs). Then, an expression quantitative trait locus (eQTL) analysis combined with previously analyzed RNA data were used to examine the DEGs. Finally, the serum levels of 13 cytokines were detected before and after LPS treatment in 40 samples to confirm the findings from eQTL analysis.

Results

A total of 319 significant eQTL were found, and both eQTL analysis and RNA sequencing showed some DEGs were involved in the connective tissue disorders and inflammatory diseases. DEGs that function to negatively regulate immunity were closely related to the pathogenesis of KD. In addition, the serum levels of IL-10 (an inflammatory and immunosuppressive factor) and SCD25 (an important immunosuppressant) reduced significantly in the KD patients.

Conclusion

Our study shows the expression of factors responsible for the negative control of innate immunity is altered, which plays an important role in the etiology of KD.

Dysregulated Circulating Apoptosis- and Autophagy-Related lncRNAs as Diagnostic Markers in Coronary Artery Disease

Objective

Increasing evidence emphasizes the implications of dysregulated apoptosis and autophagy cellular processes in coronary artery disease (CAD). Herein, we aimed to explore apoptosis- and autophagy-related long noncoding RNAs (lncRNAs) in peripheral blood of CAD patients.

Methods

The mRNA and lncRNA expression profiles were retrieved from the Gene Expression Omnibus (GEO) database. With ∣fold change | >1.5 and adjusted p value < 0.05, differentially expressed apoptosis- and autophagy-related mRNAs were screened between CAD and healthy blood samples. Also, differentially expressed lncRNAs were identified for CAD. Using the psych package, apoptosis- and autophagy-related lncRNAs were defined with Spearson's correlation analysis. Receiver operating characteristic (ROC) curves were conducted for the assessment of the diagnosed efficacy of these apoptosis- and autophagy-related lncRNAs.

Results

Our results showed that 24 apoptosis- and autophagy-related mRNAs were abnormally expressed in CAD than normal controls. 12 circulating upregulated and 1 downregulated apoptosis- and autophagy-related lncRNAs were identified for CAD. The ROCs confirmed that AC004485.3 (AUC = 0.899), AC004920.3 (AUC = 0.93), AJ006998.2 (AUC = 0.776), H19 (AUC = 0.943), RP5-902P8.10 (AUC = 0.956), RP5-1114G22.2 (AUC = 0.883), RP11-247A12.1 (AUC = 0.885), RP11-288L9.4 (AUC = 0.928), RP11-344B5.2 (AUC = 0.858), RP11-452C8.1 (AUC = 0.929), RP11-565A3.1 (AUC = 0.893), and XXbac-B33L19.4 (AUC = 0.932) exhibited good performance in differentiating CAD from healthy controls.

Conclusion

Collectively, our findings proposed that circulating apoptosis- and autophagy-related lncRNAs could become underlying diagnostic markers for CAD in clinical practice.

Upregulation of T Cell Receptor Signaling Pathway Components in Gestational Diabetes Mellitus Patients: Joint Analysis of mRNA and circRNA Expression Profiles

OBJECTIVE

Gestational diabetes mellitus (GDM) is one of the most common complications of pregnancy, and its pathogenesis is still unclear. Studies have shown that circular RNAs (circRNAs) can regulate blood glucose levels by targeting mRNAs, but the role of circRNAs in GDM is still unknown. Therefore, a joint microarray analysis of circRNAs and their target mRNAs in GDM patients and healthy pregnant women was carried out.

METHODS

In this study, microarray analyses of mRNA and circRNA in 6 GDM patients and 6 healthy controls were conducted to identify the differentially expressed mRNA and circRNA in GDM patients, and some of the discovered mRNAs and circRNAs were further validated in additional 56 samples by quantitative realtime PCR (qRT-PCR) and droplet digital PCR (ddPCR).

RESULTS

Gene ontology and pathway analyses showed that the differentially expressed genes were significantly enriched in T cell immune-related pathways. Cross matching of the differentially expressed mRNAs and circRNAs in the top 10 KEGG pathways identified 4 genes (CBLB, ITPR3, NFKBIA, and ICAM1) and 4 corresponding circRNAs (circ-CBLB, circ-ITPR3, circ-NFKBIA, and circ-ICAM1), and these candidates were subsequently verified in larger samples. These differentially expressed circRNAs and their linear transcript mRNAs were all related to the T cell receptor signaling pathway, and PCR results confirmed the initial microarray results. Moreover, circRNA/miRNA/mRNA interactions and circRNA-binding proteins were predicted, and circ-CBLB, circ-ITPR3, and circ-ICAM1 may serve as GDM-related miRNA sponges and regulate the expression of CBLB, ITPR3, NFKBIA, and ICAM1 in cellular immune pathways.

CONCLUSION

Upregulation of T cell receptor signaling pathway components may represent the major pathological mechanism underlying GDM, thus providing a potential approach for the prevention and treatment of GDM.

Inositol 1,4,5-Trisphosphate Receptors in Human Disease: A Comprehensive Update

Inositol 1,4,5-trisphosphate receptors (ITPRs) are intracellular calcium release channels located on the endoplasmic reticulum of virtually every cell. Herein, we are reporting an updated systematic summary of the current knowledge on the functional role of ITPRs in human disorders. Specifically, we are describing the involvement of its loss-of-function and gain-of-function mutations in the pathogenesis of neurological, immunological, cardiovascular, and neoplastic human disease. Recent results from genome-wide association studies are also discussed.

Insights Into Coronary Artery Lesions in Kawasaki Disease

This review summarizes recent advances in understanding the development of coronary arteritis in Kawasaki disease. Kawasaki disease is the most common cause of acquired heart disease among children characterized with coronary artery abnormalities, which can cause myocardial ischemia, infarction, and even death. The pathogenic factors of Kawasaki disease and the pathological process of coronary artery disease are not clear at present, which brings challenges to the prevention and treatment of the disease. The treatment of Kawasaki disease focuses mainly on timely administration of intravenous high doses of immunoglobulin and aspirin. However, there are still some patients who do not respond well to this standard treatment, and its management remains a challenge. As a result, coronary artery lesions still occur in patients and affect their quality of life. In this review, we discuss updated research data of Kawasaki disease coronary artery lesions.

Coronary Aneurysm: An Enigma Wrapped in a Mystery

Coronary aneurysms are defined as localized dilatations of the coronary arteries. In this review, we will analyze the most important aspects of this rare condition while trying to provide answers to the following questions: What is a coronary aneurysm? What causes coronary aneurysm? Do coronary aneurysms cause symptoms? Can coronary aneurysms rupture? How do we treat coronary aneurysms?

Correlation Between Altered DNA Methylation of Intergenic Regions of ITPR3 and Development of Delayed Cerebral Ischemia in Patients with Subarachnoid Hemorrhage

BACKGROUND

Delayed cerebral ischemia (DCI) is related to the major causes of morbidity and mortality in patients following subarachnoid hemorrhage (SAH); however, little is known about the role of epigenetics in the pathogenesis of DCI. We investigated the specific DNA methylation profile that may affect the expression of inositol 1-,4-,5-trisphosphate receptor (ITPR3) responsible for cerebral vasospasm following SAH.

METHODS

We prospectively studied patients with SAH between March 2015 and October 2018. The degree of methylation in the distal intergenic region (IGR) located on ITPR3 and gene expression were measured using methylation-specific polymerase chain reaction (MSP) and quantitative real-time polymerase chain reaction (qPCR). To investigate the regulatory mechanims of DNA hypermethylation, we further analyzed the mRNA expression of DNA methyltransferase (DNMT1) and ten-eleven translocation enzymes (TET1, TET2, and TET3).

RESULTS

A total of 42 patients were included in our analysis. Patients with SAH and DCI had significantly higher levels of methylation intensity of distal IGR upstream of ITPR3 than those without DCI (median, 0.941 [interquartile range (IQR), 0.857-0.984] versus (0.670 [IQR, 0.543-0.761]; P < 0.001). In addition, patients with DCI showed decreased mRNA expression of ITPR3 compared with patients without DCI (median, 0.039 [IQR, 0.030-0.045] vs. 0.047 [IQR, 0.038-0.064]; P = 0.0328). Patients with DCI had higher DNMT1 expression (P < 0.001) and lower TET1 expression (P = 0.040) than those without DCI; however, differences in TET2 and TET3 levels between the 2 groups were not statistically significant.

CONCLUSIONS

Hypermethylation of the distal IGR located upstream of ITPR3 is related to greater DCI development in patients with SAH. Further studies of the precise mechanisms of methylation degree and DCI development using in vitro and in vivo models are needed.

The miRNA-608 rs4919510 G>C polymorphism confers reduce coronary injury of Kawasaki disease in a Southern Chinese population

Kawasaki disease (KD) is also called mucocutaneous lymph node syndrome and is an acute febrile pediatric disease characterized by systemic vasculitis. KD typically occurs in children 5 years old or younger and occurs more often in males than in females. miRNA-608 has been reported to interact with interleukin-6 and affect innate immunity. The immune-mediated inflammation could induce the occurrence of KD; however, there is no previous research focused on the relationship between miRNA-608 polymorphism and the KD risk. The present study explored the correlation between the miRNA-608 rs4919510 G>C polymorphism and the risk for KD. We recruited 532 patients with KD and 623 controls to genotype the miRNA-608 rs4919510 G>C polymorphism with a TaqMan allelic discrimination assay. Single-locus analysis showed no significant association between miRNA rs4919510 G>C polymorphism and KD susceptibility. However in an analysis stratified by age, gender, and coronary artery lesion (CAL), we found a relationship between the miRNA-608 rs4919510 G>C polymorphism and KD susceptibility. When KD patients were stratified by coronary injury, the CG/CC genotypes of the miRNA-608 rs4919510 G>C polymorphism contributed to a higher occurrence of KD than that was found in the GG genotype patients (adjusted odds ratio = 0.74, 95% CI = 0.56-0.98, P = 0.033). The present study demonstrated that the miRNA-608 rs4919510 G>C polymorphism may have a CAL-related relationship with KD susceptibility that has not been previously revealed.

Pathophysiological consequences of isoform-specific IP3 receptor mutations

Ca²⁺ signaling governs a diverse range of cellular processes and, as such, is subject to tight regulation. A main component of the complex intracellular Ca²⁺-signaling network is the inositol 1,4,5-trisphosphate (IP₃) receptor (IP₃R), a tetrameric channel that mediates Ca²⁺ release from the endoplasmic reticulum (ER) in response to IP₃. IP₃R function is controlled by a myriad of factors, such as Ca²⁺, ATP, kinases and phosphatases and a plethora of accessory and regulatory proteins. Further complexity in IP₃R-mediated Ca²⁺ signaling is the result of the existence of three main isoforms (IP₃R1, IP₃R2 and IP₃R3) that display distinct functional characteristics and properties. Despite their abundant and overlapping expression profiles, IP₃R1 is highly expressed in neurons, IP₃R2 in cardiomyocytes and hepatocytes and IP₃R3 in rapidly proliferating cells as e.g. epithelial cells. As a consequence, dysfunction and/or dysregulation of IP₃R isoforms will have distinct pathophysiological outcomes, ranging from neurological disorders for IP₃R1 to dysfunctional exocrine tissues and autoimmune diseases for IP₃R2 and -3. Over the past years, several IP₃R mutations have surfaced in the sequence analysis of patient-derived samples. Here, we aimed to provide an integrative overview of the clinically most relevant mutations for each IP₃R isoform and the subsequent molecular mechanisms underlying the etiology of the disease.

Lack of association between miR-218 rs11134527 A>G and Kawasaki disease susceptibility

Kawasaki disease (KD) is a type of disease that includes the development of a fever that lasts at least 5 days and involves the clinical manifestation of multicellular vasculitis. KD has become one of the most common pediatric cardiovascular diseases. Previous studies have reported that miR-218 rs11134527 A>G is associated with susceptibility to various cancer risks. However, there is a lack of evidence regarding the relationship between this polymorphism and KD risk. The present study explored the correlation between the miR-218 rs11134527 A>G polymorphism and the risk of KD. We recruited 532 patients with KD and 623 controls to genotype the miR-218 rs11134527 A>G polymorphism with a TaqMan allelic discrimination assay. Our results illustrated that the miR-218 rs11134527 A>G polymorphism was not associated with KD risk. In an analysis stratified by age, sex, and coronary artery lesions, we found only that the risk of KD was significantly decreased for children older than 5 years (GG vs. AA/AG: adjusted OR = 0.26, 95% CI = 0.07–0.94, P=0.041). The present study demonstrated that the miR-218 rs1113452 A>G polymorphism may have an age-related relationship with KD susceptibility that has not previously been revealed.

A critical appraisal of the role of intracellular Ca2+-signaling pathways in Kawasaki disease

Kawasaki disease is a multi-systemic vasculitis that generally occurs in children and that can lead to coronary artery lesions. Recent studies showed that Kawasaki disease has an important genetic component. In this review, we discuss the single-nucleotide polymorphisms in the genes encoding proteins with a role in intracellular Ca²⁺ signaling: inositol 1,4,5-trisphosphate 3-kinase C, caspase-3, the store-operated Ca²⁺-entry channel ORAI1, the type-3 inositol 1,4,5-trisphosphate receptor, the Na⁺/Ca²⁺ exchanger 1, and phospholipase Cß4 and Cß1. An increase of the free cytosolic Ca²⁺ concentration is proposed to be a major factor in susceptibility to Kawasaki disease and disease outcome, but only for polymorphisms in the genes encoding the inositol 1,4,5-trisphosphate 3-kinase C and the Na⁺/Ca²⁺ exchanger 1, the free cytosolic Ca²⁺ concentration was actually measured and shown to be increased. Excessive cytosolic Ca²⁺ signaling can result in hyperactive calcineurin in T cells with an overstimulated nuclear factor of activated T cells pathway, in hypersecretion of interleukin-1ß and tumor necrosis factor-α by monocytes/macrophages, in increased urotensin-2 signaling, and in an overactivation of vascular endothelial cells.

High neutrophil : lymphocyte ratio is associated with refractory Kawasaki disease

BACKGROUND

The clinical significance of the neutrophil : lymphocyte ratio (NLR) has not yet been fully elucidated in Kawasaki disease (KD). The purpose of this study was to investigate the relationship between NLR and response to i.v. immunoglobulin (IVIG), and its effect on coronary abnormalities in KD.

METHODS

A total of 196 KD patients treated with IVIG were analyzed. Baseline NLR was evaluated immediately before IVIG therapy and the patients classified into two groups according to NLR. The clinical data, other inflammatory biomarkers, and coronary complications were also assessed.

RESULTS

Kawasaki disease patients with NLR ≥ 5 had a greater incidence of IVIG refractoriness than the NLR < 5 group (31.7% vs 4.3%, P < 0.001), but this was not related to the development of coronary abnormalities. The change in NLR after IVIG (i.e. ΔNLR) was significantly decreased in the coronary abnormality group (2.65 ± 1.88 vs 3.81 ± 2.55, P = 0.042). On multivariate analysis, high NLR and CRP were independent predictors of IVIG refractoriness during the acute phase of KD (P = 0.032 in NLR; P = 0.029 in CRP, respectively).

CONCLUSIONS

High NLR was closely associated with resistance to IVIG, but it was not related to the occurrence of coronary abnormalities in KD. Low ΔNLR after IVIG, however, was significantly associated with coronary artery abnormalities.

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.

Genetic variants in PLCB4/PLCB1 as susceptibility loci for coronary artery aneurysm formation in Kawasaki disease in Han Chinese in Taiwan

Kawasaki disease (KD) is an acute, inflammatory, and self-limited vasculitis affecting infants and young children. Coronary artery aneurysm (CAA) formation is the major complication of KD and the leading cause of acquired cardiovascular disease among children. To identify susceptible loci that might predispose patients with KD to CAA formation, a genome-wide association screen was performed in a Taiwanese KD cohort. Patients with both KD and CAA had longer fever duration and delayed intravenous immunoglobulin treatment time. After adjusting for these factors, 100 susceptibility loci were identified. Four genes were identified from a single cluster of 35 using the Ingenuity Pathway Analysis (IPA) Knowledge Base. Silencing KCNQ5, PLCB1, PLCB4, and PLCL1 inhibited the effect of lipopolysaccharide-induced endothelial cell inflammation with varying degrees of proinflammatory cytokine expression. PLCB1 showed the most significant inhibition. Endothelial cell inflammation was also inhibited by using a phospholipase C (PLC) inhibitor. The single nucleotide polymorphism rs6140791 was identified between PLCB4 and PLCB1. Plasma PLC levels were higher in patients with KD and CC+CG rs6140791genotypes, and these genotypes were more prevalent in patients with KD who also had CAA. Our results suggest that polymorphism of the PLCB4/B1 genes might be involved in the CAA pathogenesis of KD.

Pharmacogenetics of cardiac inotropy

The ability to stimulate cardiac contractility is known as positive inotropy. Endogenous hormones, such as adrenaline and several natural or synthetic compounds possess this biological property, which is invaluable in the modern cardiovascular therapy setting, especially in acute heart failure or in cardiogenic shock. A number of proteins inside the cardiac myocyte participate in the molecular pathways that translate the initial stimulus, that is, the hormone or drug, into the effect of increased contractility (positive inotropy). Genetic variations (polymorphisms) in several genes encoding these proteins have been identified and characterized in humans with potentially significant consequences on cardiac inotropic function. The present review discusses these polymorphisms and their effects on cardiac inotropy, along with the individual pharmacogenomics of the most important positive inotropic agents in clinical use today. Important areas for future investigations in the field are also highlighted.

Meta-analysis of the relationship between single nucleotide polymorphism rs72689236 of caspase-3 and Kawasaki disease

Kawasaki disease is a pediatric systemic vasculitis of unknown etiology, for which a genetic influence is suspected. But whether single nucleotide polymorphism (SNP) of caspase-3 rs72689236 is associated with Kawasaki disease is controversial. The aim of our study is to assess the association between the SNP of caspase-3 and risk for Kawasaki disease. We searched PubMed, MEDLINE, EMBASE, Springer, Elsevier Science Direct, Cochrane Library Google scholar, CNKI (China National Knowledge Infrastructure, in Chinese) and Wanfang database (in Chinese) to identify studies investigating the association between rs72689236 polymorphism and Kawasaki disease occurrence. There were five eligible studies, which included 4,241 (case group 1,560; control group 2,681) participants in this meta-analysis. Pooled odds ratios (ORs) and 95 % confidence intervals (95 % CIs) were calculated in a fixed-effects model (the Mantel-Haenszel method) or a random-effects model (the DerSimonian and Laird method) when appropriate. Significant associations were found under the overall ORs for A-allele comparison (A vs. G, pooled OR 1.33, 95 % CI 1.21-1.46), AA versus GG comparison (pooled OR 1.64, 95 % CI 1.35-2.00), GA versus GG comparison (pooled OR 1.42, 95 % CI 1.24-1.63), recessive model (AA vs. GG + GA, pooled OR 1.37, 95 % CI 1.15-1.64) and dominant model (AA + GA vs. GG, pooled OR 1.47, 95 % CI 1.29-1.67). This meta-analysis suggested that SNP rs72689236 of caspase-3 might be associated with susceptibility of Kawasaki disease and the allele A might increase the risk of Kawasaki disease in Asian samples such as Japanese and Chinese. In addition, individual studies with large sample size are needed to further evaluate the associations in various ethnic populations.

Mercury promotes catecholamines which potentiate mercurial autoimmunity and vasodilation: implications for inositol 1,4,5-triphosphate 3-kinase C susceptibility in kawasaki syndrome

Previously, we reviewed biological evidence that mercury could induce autoimmunity and coronary arterial wall relaxation as observed in Kawasaki syndrome (KS) through its effects on calcium signaling, and that inositol 1,4,5-triphosphate 3-kinase C (ITPKC) susceptibility in KS would predispose patients to mercury by increasing Ca²⁺ release. Hg²⁺ sensitizes inositol 1,4,5-triphosphate (IP3) receptors at low doses, which release Ca²⁺ from intracellular stores in the sarcoplasmic reticulum, resulting in delayed, repetitive calcium influx. ITPKC prevents IP3 from triggering IP3 receptors to release calcium by converting IP3 to inositol 1,3,4,5-tetrakisphosphate. Defective IP3 phosphorylation resulting from reduced genetic expressions of ITPKC in KS would promote IP3, which increases Ca²⁺ release. Hg²⁺ increases catecholamine levels through the inhibition of S-adenosylmethionine and subsequently catechol-O-methyltransferase (COMT), while a single nucleotide polymorphism of the COMT gene (rs769224) was recently found to be significantly associated with the development of coronary artery lesions in KS. Accumulation of norepinephrine or epinephrine would potentiate Hg²⁺-induced calcium influx by increasing IP3 production and increasing the permeability of cardiac sarcolemma to Ca²⁺. Norepinephrine and epinephrine also promote the secretion of atrial natriuretic peptide, a potent vasodilator that suppresses the release of vasoconstrictors. Elevated catecholamine levels can induce hypertension and tachycardia, while increased arterial pressure and a rapid heart rate would promote arterial vasodilation and subsequent fatal thromboses, particularly in tandem. Genetic risk factors may explain why only a susceptible subset of children develops KS although mercury exposure from methylmercury in fish or thimerosal in pediatric vaccines is nearly ubiquitous. During the infantile acrodynia epidemic, only 1 in 500 children developed acrodynia whereas mercury exposure was very common due to the use of teething powders. This hypothesis mirrors the leading theory for KS in which a widespread infection only induces KS in susceptible children. Acrodynia can mimic the clinical picture of KS, leading to its inclusion in the differential diagnosis for KS. Catecholamine levels are often elevated in acrodynia and may also play a role in KS. We conclude that KS may be the acute febrile form of acrodynia.

Association between GRIN3A gene polymorphism in Kawasaki disease and coronary artery aneurysms in Taiwanese children

Kawasaki disease (KD) is pediatric systemic vasculitis with the classic complication of coronary artery aneurysm (CAA). It is the leading cause of acquired cardiovascular diseases in children. Some severe cases present with multi-organ involvement or neurological dysfunction. To identify the role of the glutamate receptor, ionotropic, N-methyl-d-aspartate 3A (GRIN3A) in KD, we investigated genetic variations in GRIN3A in a Taiwanese cohort of 262 KD patients (76 with and 186 without CAA complications). We used univariate and multivariate regression analyses to identify the associations between clinical characteristics and GRIN3A genetic variations in KD. According to univariate regression analysis, CAA formation in KD was significantly associated with fever duration (p < 0.0001), first Intravenous immunoglobulin (IVIG) used (days after day one of fever) (p < 0.0001), and the GRIN3A (rs7849782) genetic variant (p < 0.001). KD patients with GG+GC genotype showed a lower rate of developing CAA (GG+GC genotype: odds ratio = 0.26; 95% CI = 0.14–0.46). Significant associations were identified between KD with CAA complication and the GRIN3A (rs7849782) genetic variant by using multivariate regression analysis. Specifically, significant correlations were observed between KD with CAA complications and the presence of GG+GC genotypes for the GRIN3A rs7849782 single-nucleotide polymorphism (full model: odds ratio = 0.25; 95% CI = 0.14–0.46). Our results suggest that a polymorphism of the GRIN3A gene may play a role in KD pathogenesis.

Can Coronary Artery Involvement in Kawasaki Disease be Predicted?

Background: Coronary artery involvement is seen in approximately 15–20% of children with Kawasaki disease. There is conflicting literature regarding the clinical and laboratory findings associated with coronary artery involvement. In this retrospective study, we attempt identification of predictive factors for coronary artery involvement at our institute and review the existing literature. Methods and results: A review of 203 patients (65% males) with Kawasaki disease was performed, of whom 33 (16.3%) had coronary artery involvement. High erythrocyte sedimentation rate, high platelet count, low hematocrit, low albumin levels, and refractory Kawasaki disease showed significant association with coronary artery involvement. High erythrocyte sedimentation rate and refractory Kawasaki disease were found to be independent predictors of coronary artery involvement. Review of literature suggested a wide range of coronary involvement (<5% to >60%), and highly conflicting clinical and laboratory associations. Conclusion: It remains difficult to accurately determine risk of coronary artery involvement, although some laboratory markers may provide information that is helpful for parental counseling and clinical follow up. Future identification of novel biomarkers and host predispositions may further our understanding of coronary artery risks and help personalize therapy for Kawasaki disease.

Understanding the pathogenesis of Kawasaki disease by network and pathway analysis

Kawasaki disease (KD) is a complex disease, leading to the damage of multisystems. The pathogen that triggers this sophisticated disease is still unknown since it was first reported in 1967. To increase our knowledge on the effects of genes in KD, we extracted statistically significant genes so far associated with this mysterious illness from candidate gene studies and genome-wide association studies. These genes contributed to susceptibility to KD, coronary artery lesions, resistance to initial IVIG treatment, incomplete KD, and so on. Gene ontology category and pathways were analyzed for relationships among these statistically significant genes. These genes were represented in a variety of functional categories, including immune response, inflammatory response, and cellular calcium ion homeostasis. They were mainly enriched in the pathway of immune response. We further highlighted the compelling immune pathway of NF-AT signal and leukocyte interactions combined with another transcription factor NF- κ B in the pathogenesis of KD. STRING analysis, a network analysis focusing on protein interactions, validated close contact between these genes and implied the importance of this pathway. This data will contribute to understanding pathogenesis of KD.

Inositol trisphosphate receptors in smooth muscle cells

Inositol 1,4,5-trisphosphate receptors (IP(3)Rs) are a family of tetrameric intracellular calcium (Ca(2+)) release channels that are located on the sarcoplasmic reticulum (SR) membrane of virtually all mammalian cell types, including smooth muscle cells (SMC). Here, we have reviewed literature investigating IP(3)R expression, cellular localization, tissue distribution, activity regulation, communication with ion channels and organelles, generation of Ca(2+) signals, modulation of physiological functions, and alterations in pathologies in SMCs. Three IP(3)R isoforms have been identified, with relative expression and cellular localization of each contributing to signaling differences in diverse SMC types. Several endogenous ligands, kinases, proteins, and other modulators control SMC IP(3)R channel activity. SMC IP(3)Rs communicate with nearby ryanodine-sensitive Ca(2+) channels and mitochondria to influence SR Ca(2+) release and reactive oxygen species generation. IP(3)R-mediated Ca(2+) release can stimulate plasma membrane-localized channels, including transient receptor potential (TRP) channels and store-operated Ca(2+) channels. SMC IP(3)Rs also signal to other proteins via SR Ca(2+) release-independent mechanisms through physical coupling to TRP channels and local communication with large-conductance Ca(2+)-activated potassium channels. IP(3)R-mediated Ca(2+) release generates a wide variety of intracellular Ca(2+) signals, which vary with respect to frequency, amplitude, spatial, and temporal properties. IP(3)R signaling controls multiple SMC functions, including contraction, gene expression, migration, and proliferation. IP(3)R expression and cellular signaling are altered in several SMC diseases, notably asthma, atherosclerosis, diabetes, and hypertension. In summary, IP(3)R-mediated pathways control diverse SMC physiological functions, with pathological alterations in IP(3)R signaling contributing to disease.

The Molecular Biology and Treatment of Systemic Vasculitis in Children

Primary systemic vasculitides are rare in childhood but are associated with significant morbidity and mortality. The cause of the majority of vasculitides is unknown, although it is likely that a complex interaction between environmental factors, such as infections and inherited host responses, triggers the disease and determines the vasculitis phenotype. Several genetic polymorphisms in vasculitides have now been described, which may be relevant in terms of disease predisposition or development of disease complications. Treatment regimens continue to improve with the use of different immunosuppressive medications and newer therapeutic approaches such as biologic agents. This chapter reviews recent studies shedding light on the pathogenesis of vasculitis with emphasis on molecular biology where known, and summarizes current treatment strategies. We discuss new emerging challenges particularly with respect to the long-term cardiovascular morbidity for children with systemic vasculitis and emphasize the importance of future international multicenter collaborative studies to further increase and standardize the scientific base investigating and treating childhood vasculitis.

Analysis of IP3 receptors in and out of cells

BACKGROUND

Inositol 1,4,5-trisphosphate receptors (IP3R) are expressed in almost all animal cells. Three mammalian genes encode closely related IP3R subunits, which assemble into homo- or hetero-tetramers to form intracellular Ca2+ channels.

SCOPE OF THE REVIEW

In this brief review, we first consider a variety of complementary methods that allow the links between IP3 binding and channel gating to be defined. How does IP3 binding to the IP3-binding core in each IP3R subunit cause opening of a cation-selective pore formed by residues towards the C-terminal? We then describe methods that allow IP3, Ca2+ signals and IP3R mobility to be examined in intact cells. A final section briefly considers genetic analyses of IP3R signalling.

MAJOR CONCLUSIONS

All IP3R are regulated by both IP3 and Ca2+. This allows them to initiate and regeneratively propagate intracellular Ca2+ signals. The elementary Ca2+ release events evoked by IP3 in intact cells are mediated by very small numbers of active IP3R and the Ca2+-mediated interactions between them. The spatial organization of these Ca2+ signals and their stochastic dependence on so few IP3Rs highlight the need for methods that allow the spatial organization of IP3R signalling to be addressed with single-molecule resolution.

GENERAL SIGNIFICANCE

A variety of complementary methods provide insight into the structural basis of IP3R activation and the contributions of IP3-evoked Ca2+ signals to cellular physiology. This article is part of a Special Issue entitled Biochemical, biophysical and genetic approaches to intracellular calcium signaling.