Metabolic profiling reveals altered tryptophan metabolism in patients with kawasaki disease

Identification of m6A-related biomarkers in Kawasaki disease

Kawasaki disease (KD) is a widely prevalent acute vasculitis in children that often leads to cardiovascular complications. Although m6A modification plays a crucial role in various cardiovascular diseases, m6A-related biomarkers for KD remain unknown. We utilized GEO datasets to perform WGCNA to identify m6A-related differentially expressed genes in KD. Feature genes associated with m6A and key immune cells were identified using RF and SVM-RFE algorithms, and CIBERSORT, and the correlation was evaluated using CytoHubba and ROC analysis. The expression of hub genes was assessed in blood from patients with KD and in mice with CAWS-induced vasculitis. Our analysis identified four m6A-related hub genes: SNRK, PCCB, PIGP, and PRPS1, which exhibited significant negative correlation with M2 macrophages. A total of 477 microRNAs, 22 lncRNAs, and 3 snRNAs were identified as potential regulators of these hub genes. The ROC analysis demonstrated a robust diagnostic accuracy of these hub genes for KD. The expression of these hub genes was reduced in blood from patients with KD and in mice with vasculitis. In conclusion, SNRK, PCCB, PIGP, and PRPS1 demonstrate significant diagnostic value for KD and may also be considered as potential therapeutic targets.

Diverse Physiological Roles of Kynurenine Pathway Metabolites: Updated Implications for Health and Disease

Tryptophan is an essential amino acid critical for human health. It plays a pivotal role in numerous physiological and biochemical processes through its metabolism. The kynurenine (KYN) pathway serves as the principal metabolic route for tryptophan, producing bioactive metabolites, including KYN, quinolinic acid, and 3-hydroxykynurenine. Numerous studies are actively investigating the relationship between tryptophan metabolism and physiological functions. These studies are highlighting the interactions among metabolites that may exert synergistic or antagonistic effects, such as neuroprotective or neurotoxic, and pro-oxidative or antioxidant activities. Minor disruptions in the homeostasis of these metabolites can result in immune dysregulation, contributing to a spectrum of diseases. These diseases include neurological disorders, mental illnesses, cardiovascular conditions, autoimmune diseases, and chronic kidney disease. Therefore, understanding the physiological roles of the KYN pathway metabolites is essential for elucidating the contribution of tryptophan metabolism to health regulation. The present review emphasizes the physiological roles of KYN pathway metabolites and their mechanisms in disease development, aiming to establish a theoretical basis for leveraging dietary nutrients to enhance human health.

Inflammatory Markers in the Blood of Spastic Cerebral Palsy Children: A Case-Control Study

OBJECTIVES

The aim was to simultaneously investigate inflammatory biomarkers, neopterin, the kynurenine/tryptophan (Kyn/Trp) pathway, vitamin D (VitD), vitamin D binding protein (VDBP), and erythrocyte folate, in cerebral palsy (CP).

METHODS

A case-control study was conducted at Mersin University Hospital. Three- to ten-year-old patients with spastic CP (n = 50) and age- and gender-matched healthy controls (n = 55) were included. Serum levels of neopterin, Trp, Kyn and 25OHD, plasma VDBP, and erythrocyte folate concentrations were measured. Indoleamine-2,3-dioxygenase 1 (IDO-1) enzyme activity was evaluated according to the Kyn/Trp ratio. Comparison and correlation analyses were performed.

RESULTS

The levels of neopterin, Trp, and Kyn were lower in children with CP than in healthy controls (p = 0.037, p < 0.001, and p = 0.003, respectively). IDO1 was not significantly different between the CP and control groups (p = 0.214). The levels of VitD and VDBP were higher in children with CP (p < 0.001 and p = 0.001, respectively). The level of erythrocyte folate was also higher in children with CP (p < 0.001). No significant correlation was found between age and inflammatory biomarkers in the CP group. Neopterin was correlated with the level of Gross Motor Function Classification System (GMFCS) level (r = 0.292, p = 0.044), while there was no significant correlation between the other biomarkers and the level of GMFCS in the CP group.

CONCLUSIONS

Inflammatory biomarkers of neopterin and Kyn are lower, inflammatory biomarkers of VDBP and erythrocyte folate are higher, and anti-inflammatory VitD is higher in children with spastic CP compared to healthy children. More knowledge is needed to demonstrate inflammatory and anti-inflammatory status in children with CP.

Integrated Metabolomics and Transcriptomics Analyses Reveal Metabolic Changes in Primary Angiitis of the Central Nervous System

Purpose

Metabolic characterization of primary angiitis of the central nervous system (PACNS) is crucial for understanding the disease pathogenesis and progression mechanisms, but it has not been reported in patients. This study aimed to explore changes in the plasma metabolome during the active and remission phases of PACNS and identify potential biomarkers.

Methods

We collected plasma samples from 35 patients with PACNS during the active and remission phases and 22 samples from patients with non-inflammatory disease as controls. Liquid and gas chromatography-mass spectrometry were used to analyze 63 plasma samples from 57 patients metabolically. Meanwhile, we cross-validated the metabolomics results with brain tissue transcriptomic data from comprehensive gene expression databases, enhancing the reliability of our conclusions.

Results

A total of 3,233 metabolites were identified. Enrichment analysis showed significant changes in lactate/amino acid/glycerol-pyruvic-tricarboxylic acid, glycerophospholipid/sphingolipid-membrane metabolism, lysine/tryptophan-essential amino acid metabolism, and uracil metabolism pathways during the active phase of PACNS. These findings were confirmed in both the remission phase of PACNS patients and the transcriptomic samples. Meanwhile, metabolic abnormalities in patients with PACNS were observed with benzoxazole, sesquiterpenoid, and octyl-phenolic products, and enrichment of environmental pollutants and their estrogen-like effects. Twelve metabolites, including D-Ribose, 13s-HPODE, and C16 Sphinganine, showed potential diagnostic and therapeutic evaluation value.

Conclusion

Our study identified potential biomarkers and metabolic characteristics of PACNS using integrated metabolomics and transcriptomics approaches. These findings highlight the importance of understanding PACNS from a metabolic perspective and guide future diagnostic and therapeutic strategies.

Development of a liquid chromatography-mass spectrometry based targeted metabolomics method for discovering diagnostic biomarkers in Kawasaki disease

Kawasaki disease (KD) has emerged as the leading cause of acquired heart disease in children, primarily due to the absence of highly sensitive and specific biomarkers for early and accurate diagnosis. To address this issue, a simple and comprehensive targeted metabolomics method employing ultra high-performance liquid chromatography coupled with Q-TRAP mass spectrometry has been developed to identify new metabolite biomarkers for KD. This method enables the simultaneous quantification of 276 metabolites, covering 60 metabolic pathways, with a particular emphasis on metabolites relevant to KD. The use of nine ISs and commercial quality control samples significantly enhances both accuracy and precision. Through validation and application to serum samples from patients with KD, seventeen differential serum metabolites were identified. The altered metabolites are primarily associated with three functional metabolic pathways: tricarboxylic acid cycle, tryptophan metabolism, and bile acid metabolism, all of which are believed to be involved in the inflammatory and immune responses in KD patients. Ultimately, eight differential metabolites (indole-3-propionic acid, thiamine, indolepyruvic acid, levodopa, l-selenomethionine, isocitric acid, trans-aconitate, and N-acetylasparagine) were identified that could potentially serve as diagnostic biomarkers with the area under the curve values exceeding 0.9. Our targeted metabolomics approach demonstrates applicability in identifying potential metabolite biomarkers for KD and holds great promise in unraveling the intricate pathophysiology of the disease.

Transcriptome meta-analysis of Kawasaki disease in humans and mice

Kawasaki Disease (KD) affects young children less than five years old with severe blood vessel inflammation. Despite being treatable, the causes and mechanisms remain elusive. This study conducted a meta-analysis of RNA sequencing (RNA-seq) data from human and animal models to explore KD's transcriptomic profile and evaluate animal models. We retrieved bulk and single-cell RNA-seq data from Gene Expression Omnibus, with blood and coronary artery samples from KD patients, aorta samples from KD mouse models (Lactobacillus casei cell wall extract-injected mice), and their controls. Upon consistent quality control, we applied Fisher's exact test to assess differential gene expression, followed by an enrichment analysis of overlapping genes. These studies identified 400 differentially expressed genes in blood samples of KD patients compared to controls and 413 genes in coronary artery samples. The data from KD blood and KD coronary artery samples shared only 16 differentially expressed genes. Eighty-one genes overlapped between KD human coronary arteries and KD mouse aortas, and 67 of these 81 genes were regulated in parallel in both humans and mice: 30 genes were up-regulated, and 37 were down-regulated. These included previously identified KD-upregulated genes: CD74, SFRP4, ITGA4, and IKZF1. Gene enrichment analysis revealed significant alterations in the cardiomyopathy pathway. Single-cell RNAseq showed a few significant markers, with known KD markers like S100A9, S100A8, CD74, CD14, IFITM2, and IFITM3, being overexpressed in KD cohorts. Gene profiles obtained from KD human coronary artery are more compatible with data from aorta samples of KD mice than blood samples of KD humans, validating KD animal models for identifying therapeutic targets. Although blood samples can be utilized to discover novel biomarkers, more comprehensive single-cell sequencing is required to detail gene expression in different blood cell populations. This study identifies critical genes from human and mouse tissues to help develop new treatment strategies for KD.

Pre- to Postbiotics: The Beneficial Roles of Pediatric Dysbiosis Associated with Inflammatory Bowel Diseases

Probiotics are "live microorganisms which, when administered in adequate amount, confer health benefits on the host". They can be found in certain foods like yogurt and kefir and in dietary supplements. The introduction of bacterial derivatives has not only contributed to disease control but has also exhibited promising outcomes, such as improved survival rates, immune enhancement, and growth promotion effects. It is interesting to note that the efficacy of probiotics goes beyond the viability of the bacteria, giving rise to concepts like paraprobiotics, non-viable forms of probiotics, and postbiotics. Paraprobiotics offer various health benefits in children with intestinal dysbiosis, contributing to improved digestive health, immune function, and overall well-being. In this review, the potential of these therapeutic applications as alternatives to pharmacological agents for treating pediatric intestinal dysbiosis will be thoroughly evaluated. This includes an analysis of their efficacy, safety, long-term benefits, and their ability to restore gut microbiota balance, improve digestive health, enhance immune function, and reduce inflammation. The aim is to determine if these non-pharmacological interventions can effectively and safely manage intestinal dysbiosis in children, reducing the need for conventional medications and their side effects.

Alteration in kynurenine pathway metabolites in young women with autoimmune thyroiditis

The kynurenine pathway (KP) of tryptophan degradation includes several compounds that reveal immunomodulatory properties. The present study aimed to investigate the alteration in KP metabolites in young women with autoimmune thyroiditis (AIT) and their associations with thyroid function. The thyroid function tests, antithyroid antibodies measurement and ultrasonography of the thyroid gland have been performed in 57 young women with AIT and 38 age-matched healthy controls. The serum levels of tryptophan, kynurenine (KYN) and its metabolites were determined, and the activity of KP enzymes was calculated indirectly as product-to-substrate ratios. KP was activated and dysregulated in AIT, along with significantly elevated levels of KYN and anthranilic acid (AA), at the expense of the reduction of kynurenic acid (KYNA), which was reflected by the increase in the AA/KYNA ratio (p < 0.001). In univariate and multiple regression analyses, peripheral deiodinase (SPINA-GD) activity in AIT was positively associated with KYNA, AA, and quinolinic acid (QA). The merger of AA, AA/KYNA ratio, QA and SPINA-GD exhibited the highest sensitivity and specificity to predict AIT (p < 0.001) in receiver operating characteristic (ROC) analysis. In conclusion, the serum KYN metabolite profile is dysregulated in young women with AIT and could serve as a new predictor of AIT risk.