Novel Compound Heterogeneous Mutations in CYB5R3 Gene Leading to Methemoglobinemia (Type I) in a Chinese Boy: Case Report and Relevant Comprehensive Analysis.

INTRODUCTION: Recessive congenital methemoglobinemia (RCM) caused by CYB5R3 deficiency due to the mutations in the reduced nicotinamide adenine dinucleotide (NADH) cytochrome b5 reductase (CYB5R) gene is an autosomal recessive inherited disease. Clinically, it can be divided into two types, namely red blood cell affected type (RCM I) and systemically affected type (RCM II). CASE PRESENTATION: A 5-year-old male patient was diagnosed with cyanosis for 5 years. Physical examination showed cyanosis in areas such as the lips, fingers, and toes. Laboratory examination revealed low pulse oxygen saturation (81%) and increased blood methemoglobin (23.6%). Gene testing revealed the compound heterozygous mutations in the CYB5R3 gene, c.149G>A (p.Arg50Gln) and c.331A>G (p.Lys111Glu), respectively originating from his parents. By constructing 3D models of CYB5R3 wild-type and mutant types using SWISS-MODEL software, it was found that the mutation caused significant structural abnormalities in the CYB5R protein. The relationship between CYB5R3 gene mutation sites, amino acid change, enzyme activity, and methemoglobinemia type I and II were listed and analyzed. CONCLUSION: A case of congenital RCM type I caused by compound heterozygous mutations in the CYB5R3 gene was reported, with c.331A>G (p.Lys111Glu) being the newly reported mutation. The homozygosity or heterozygosity of CYB5R3 gene mutations that lead to premature termination, loss of exons, and change in amino acid properties in FAD or NADH binding domains, is positively correlated with the severity (from type I to type II) of methemoglobinemia.

Association between TRAF1/C5 Gene Polymorphisms and IgA Vasculitis in Chinese Children.

OBJECTIVE: To investigate the association between loci rs3761847 and rs10818488 of tumor necrosis factor receptor-associated factor 1/complement C5 (TRAF1/C5) gene and the susceptibility to IgAV. METHODS: 100 blood samples of children with IgAV and 100 blood samples of healthy children were collected from the Third Xiangya Hospital of Central South University from June 2017 to June 2019. The target gene fragment was amplified by polymerase chain reaction (PCR), and the single nucleic acid gene polymorphism of the gene loci was detected by PCR sequencing based typing technique. The association between gene polymorphism of each locus and susceptibility to IgAV was analyzed. RESULTS: There were significant differences in both genotype (P < .05) and allele frequencies （P < .05) of rs3761847 of TRAF1/C5 gene between the IgAV group and the control group.Besides, the risks of developing IgAV in children with the TT genotype was 0.495 times and in children with the C allele was 1.627 times of that in children with other genotypes and alleles, respectively (P < .05). For IgAV patients, renal involvement risk in children with CC genotype was 5.859 times of that in children with other genotypes (P < .05). There were no significant differences in genotype (P > .05) and allele frequencies (P > .05) of rs10818488 of TRAF1/C5 gene between the IgAV group and the control group. IgAV patients with TT genotype had a 3.2 times higher risk of renal involvement than those with other genotypes (P < .05). CONCLUSIONS: There is an association between locus rs3761847 of TRAF1/C5 gene single nucleotide polymorphisms and susceptibility to IgAV. The T allele at locus rs3761847 of TRAF1/C5 gene may be a protective factor for IgAV. The C allele at locus rs3761847 and the T allele at locus rs10818488 of TRAF1/C5 gene may be associated with kidney injury in IgAV.

Acetylation of FOXO1 activates Bim expression involved in CVB3 induced cardiomyocyte apoptosis.

Viral myocarditis (VMC) is the major reason for sudden cardiac death among both children and young adults. Of these, coxsackievirus B3 (CVB3) is the most common causative agent of myocarditis. Recently, the role of signaling pathways in the pathogenesis of VMC has been evaluated in several studies, which has provided a new perspective on identifying potential therapeutic targets for this hitherto incurable disease. In the present study, in vivo and in vitro experiments showed that CVB3 infection leads to increased Bim expression and triggers apoptosis. In addition, by knocking down Bim using RNAi, we further confirmed the biological function of Bim in apoptosis induced by CVB3 infection. We additionally found that Bim and forkhead box O1 class (FOXO1) inhibition significantly increased the viability of CVB3-infected cells while blocking viral replication and viral release. Moreover, CVB3-induced Bim expression was directly dependent on FOXO1 acetylation, which is catalyzed by the co-regulation of CBP and SirTs. Furthermore, the acetylation of FOXO1 was an important step in Bim activation and apoptosis induced by CVB3 infection. The findings of this study suggest that CVB3 infection induces apoptosis through the FOXO1 acetylation-Bim pathway, thus providing new insights for developing potential therapeutic targets for enteroviral myocarditis.

Relationship between IL-17A gene polymorphism and susceptibility to Kawasaki disease. / IL-17AåŸºå› rs3819025ä½ç‚¹å¤šæ€æ€§ä¸Žå·å´Žç— çš„ç›¸å ³æ€§ï¼ˆè‹±æ–‡ï¼‰.

OBJECTIVES: Kawasaki disease (KD) is the most common autoimmune vasculitis syndrome in children, which supposed be a complex polygenic disorder. Interleukin-17 (IL-17) is a member of the pro-inflammatory cytokine family, which has a strong pro-inflammatory effect and can participate in various acute and chronic inflammatory responses. This study aims to investigate the relationship between the single-nucleotide polymorphism (SNP) locus rs3819025 in the IL-17A gene and the susceptibility to KD. METHODS: A total of 120 patients with KD who met the diagnostic criteria (the KD group) and 120 healthy children (the control group) were enrolled retrospectively in this study. Polymerase chain reaction (PCR) and DNA direct sequencing were used to detect the SNPs of children in the 2 groups. RESULTS: The frequencies of GG, GA, and AA genotypes of rs3819025 locus in the IL-17A gene in the KD group were 82.5%, 17.5%, and 0, respectively, and the frequencies of GG, GA, and AA genotypes in the control group were 72.5%, 22.5%, and 5.0%, respectively. There were significant differences in both genotype (χ2=7.524, P=0.023). The allele frequencies G and A of rs3819025 locus in the KD group were 91.25% and 8.75%, respectively, while those in the control group were 83.75% and 16.25%, respectively. There was significant difference between the 2 groups (χ2=6.171, P=0.013). The distribution frequencies of GG or GA genotype and G or A allele were 88.46% or 11.54% and 94.23% or 5.77% in the KD group with coronary artery lesion, respectively. The distribution frequencies of GG or GA genotype and G or A allele were 78.72% or 21.28% and 89.36% or 10.64% in the KD group without coronary artery lesion, respectively. There were no significant differences in genotype and allele frequencies of rs3819025 between the KD with coronary artery lesion group and the KD group without coronary artery lesion (both P>0.05). Besides, children with the allele A had a 2.023 times higher risk of KD than those without the allele A (χ2=6.171, P=0.013; OR=2.023, 95% CI 1.151 to 3.557). CONCLUSIONS: The locus rs3819025 in the IL-17A gene is associated with the pathogenesis of KD. The allele A of the locus rs3819025 in the IL-17A gene may be a risk factor for KD.

Coxsackievirus B3 infection induces glycolysis to facilitate viral replication.

Coxsackievirus B3 (CVB3) is a leading cause of viral myocarditis, but no effective treatment strategy against CVB3 is available. Viruses lack an inherent metabolic system and thus depend on host cellular metabolism for their benefit. In this study, we observed that CVB3 enhanced glycolysis in H9c2 rat cardiomyocytes and HL-1 mouse cardiomyocytes. Therefore, three key glycolytic enzymes, namely, hexokinase 2 (HK2), muscle phosphofructokinase (PFKM), and pyruvate kinase M2 (PKM2), were measured in CVB3-infected H9c2 and HL-1 cells. Expression levels of HK2 and PFKM, but not PKM2, were increased in CVB3-infected H9c2 cells. All three key glycolytic enzymes showed elevated expression in CVB3-infected HL-1 cells. To further investigate this, we used 2 deoxyglucose, sodium citrate, and shikonin as glycolysis inhibitors for HK2, PFKM, and PKM2, respectively. Glycolysis inhibitors significantly reduced CVB3 replication, while the glycolysis enhancer dramatically promoted it. In addition, glycolysis inhibitors decreased autophagy and accelerated autophagosome degradation. The autophagy inducer eliminated partial inhibition effects of glycolysis inhibitors on CVB3 replication. These results demonstrate that CVB3 infection enhances glycolysis and thus benefits viral replication.

A preliminary study of KAT2A on cGAS-related immunity in inflammation amplification of systemic lupus erythematosus.

Previous studies demonstrated that cGAS pathway is related to the inflammation amplification in a variety of autoimmune diseases. Lysine acetyltransferase family (KATs) can regulate the nuclear transcription or cytoplasmic activation of cGAS through different mechanisms. However, its role and related immunity patterns in systemic lupus erythematosus (SLE) have not been explored. In this study, RNA-seq and scRNA-seq profiling were performed for peripheral blood mononuclear cells (PBMCs) from patients with SLE. R packages were used for bioinformatic analysis. Cell culture, RT-PCR, western blotting, immunofluorescence, immunohistochemistry, and ELISA were used to explore gene expression in vitro or clinical specimens. Plasmid transfection and mass spectrometry were used to detect protein modifications. Eight acetyltransferase and deacetylase family members with significantly differential expression in SLE were found. Among them, KAT2A was abnormally upregulated and positively correlated with disease activity index. Further, KAT2A-cGAS pathway was aberrantly expressed in specific immune cell subsets in SLE. In vitro studies showed KAT2A modulated cGAS through increasing expression and post-translational modification. Our research provides novel insights for accurately positioning specific immune-cell subgroups in which KAT2A-cGAS reaction mainly works and KAT2A regulation patterns.

A novel compound heterozygous mutation in SLC5A2 contributes to familial renal glucosuria in a Chinese family, and a review of the relevant literature.

Familial renal glucosuria (FRG) is a rare condition that involves isolated glucosuria despite normal blood glucose levels. Mutations in the solute carrier family 5 member 2 (SLC5A2) gene, which encodes sodium­glucose cotransporter 2 (SGLT2), have been reported to be responsible for the disease. Genetic testing of the SLC5A2 gene was conducted in a Chinese family with FRG. A number of online tools were used to predict the potential effect of the identified mutations on SGLT2 function. Additionally, the SLC5A2 mutations previously reported in PubMed were summarized. A novel compound heterozygous mutation (c.514T>C, p.W172R; c.1540C>T, p.P514S) of the SLC5A2 gene in a Chinese child with FRG was identified. In total, 86 mutations of the SLC5A2 gene have been reported to be associated with FRG. The novel compound heterozygous mutation (c.514T>C, p.W172R; c.1540C>T, p.P514S) of the SLC5A2 gene may be responsible for the onset of FRG. The present study provides a starting point for further investigation of the molecular pathogenesis of the SLC5A2 gene mutation in patients with FRG.

The cytotoxicity of coxsackievirus B3 is associated with a blockage of autophagic flux mediated by reduced syntaxin 17 expression.

Coxsackievirus B3 (CVB3) is an important human pathogen linked to cardiac arrhythmias and acute heart failure. CVB3 infection has been reported to induce the formation of autophagosomes that support the viral replication in host cells. Interestingly, our study shows that the accumulation of autophagosomes during CVB3 infection is caused by a blockage of autophagosome-lysosome fusion rather than the induction of autophagosome biogenesis. Moreover, CVB3 decreases the transcription and translation of syntaxin 17 (STX17), a SNARE (soluble N-ethylmaleimide-sensitive factor activating protein receptor) protein involved in autophagosome-lysosome fusion. Overexpression of STX17 restored the autophagic flux, alleviated the virus-induced lysosomal dysfunction, and decreased the apoptosis induced by CVB3 infection in HeLa cells. Taken together, our results suggest that CVB3 infection impairs the autophagic flux by blocking autophagosome-lysosome fusion. These findings thus point to potential new therapeutic strategies targeting STX17 or autophagosome-lysosome fusion for treating CVB3-associated diseases.

[Tubulointerstitial nephritis antigen expression in chronic kidney disease and its clinical significance].

OBJECTIVE: To explore tubulointerstitial nephritis antigen (TIN-ag) expression of chronic kidney disease (CKD) patients' renal tissue and the correlation to clinical phenotype. METHODS: Through digital drawing lots, a total of 77 CKD patients from October 2012 to February 2013 at our department were randomly selected. All of them underwent biopsy. Based upon their pathological findings, they were divided into 2 groups of minimal change disease (MCD) and non-minimal change disease (NMCD). The stains of hematoxylin and eosin and Masson were used to observe renal pathological changes and immunofluorescence for detecting the TIN-ag expression of kidney tissue. The serum levels of creatinine, blood urea nitrogen, estimated glomerular filtration rate (eGFR), 24-hour urine output, 24-hour urine protein, α1-microglobulin, ß2-microglobulin, pathological casts, N-acetyl-beta-glucosaminidase (NAG), specific gravity and other clinical parameters were monitored to examine their relationship between renal tissue TIN-ag expression. RESULTS: TIN-ag expression was distinct in renal tubular basement membrane of MCD patients while weak in primary focal segmental glomerulosclerosis (FSGS)(n = 16), IgA nephropathy (n = 23), MN (n = 14) and LN (n = 15) renal tissue. Immunofluorescence quantitative analysis showed that tubular TIN-ag fluorescence intensity of NMCD group was significantly lower than that of MCD group (4.84(3.02, 10.73) vs 20.79(8.19, 37.00), P < 0.01). In addition, TIN-ag expression in renal interstitial collagen area deposition of 0 grade group was higher than that of collagen area deposition 1-3 grades group (all P < 0.05). Serum α1-microglobulin and pathological urine cast, 24-hour urine protein of CKD patients were negatively correlated with kidney tubules TIN-ag expression (r = -0.312, -0.298, -0.214, all P < 0.05). Serum creatinine, blood urea nitrogen, serum ß2-microglobulin and eGFR of CKD patients had no significant correlations with TIN-ag expression (P > 0.05). TIN-ag expression of CKD patients with lower expression levels of NAG was significantly higher than that of normal levels of NAG expression. TIN-ag expression of low urine specific gravity group was lower than that of normal urine specific gravity group (P < 0.05). CONCLUSIONS: TIN-ag expression of renal tissue tubule basement membrane in NMCD group is significantly lower than that in MCD group. TIN-ag expression is negatively correlated with renal tissue fibrosis. Expression of serum α1-microglobulin and concentrations of urinary pathology tube, 24-hour urine protein, NAG expression and urine specific gravity are negatively correlated with renal tissue TIN-ag expression in CKD patients.

Urine miRNAs: potential biomarkers for monitoring progression of early stages of diabetic nephropathy.

With a steep increase in the incidence of type 1 and 2 diabetes globally, diabetic nephropathy (DN) has now become the leading cause of renal failure in the world. There are no suitable biomarkers for the diagnosis of early stages of DN. In recent years, tremendous efforts are being made worldwide to delineate the role of micro RNAs in the pathogenesis of DN. Circulating miRNAs in serum, plasma, urine and other body fluids, which reflect a response to various pathophysiological stresses, are being investigated in the context of diabetic nephropathy. Delineation of the changes in miRNA levels in patients with DN may lead to a better understanding of the progression of the disease. We present here an exhaustive survey of the miRNA literature, highlighting various studies performed over the last decade. The aim is to assess if changes in various miRNAs could correlate with the progression of diabetic nephropathy. Based on the survey, we found that miRNA-377, miRNA-192, miRNA-216/217 and miRNA-144 are increased in body fluids of patients with DN, while miRNA-21 and miRNA-375 are decreased. Overall, there are a very few miRNAs that are kidney specific, and although significant differences were observed in the urinary excretion of certain miRNAs, they were not correlative to their levels in the blood or plasma. Thus, it is completely plausible that urine-specific miRNAs could serve as novel biomarkers for the diagnosis of early stages of diabetic nephropathy.

Low-dose paclitaxel ameliorates fibrosis in the remnant kidney model by down-regulating miR-192.

Transforming growth factor (TGF)-ß has been shown to play a central role in the development of tubulointerstitial fibrosis, which can be corrected via treatment with paclitaxel. The biology of microRNA (miR) can be modulated by paclitaxel. We hypothesized that paclitaxel may attenuate renal fibrosis in a rat model of remnant kidney disease by inhibiting TGF-ß induced-miRs. Rats in groups of 12 were subjected to 5/6 nephrectomy and received low-dose intraperitoneal injection of paclitaxel. Renal functions were assessed at 8 weeks. The TGF-ß signalling cascade and ECM proteins were evaluated by real-time polymerase chain reaction (TRT-PCR) and immunofluorescence microscopy. Animals with remnant kidneys developed hypertension, which was not relieved with paclitaxel treatment. However, paclitaxel treatment resulted in dampening the proteinuric response, reduction in serum BUN, creatinine levels and urine protein : creatinine ratio and normalization of creatinine clearance. These effects were accompanied by the inhibition of Smad2/3 activation, attenuation of renal fibrosis and normalization of integrin-linked kinase (ILK), COL(I)A1, COL(IV)A2 and α-SMA expression. Also, paclitaxel down-regulated the expression of miR-192, miR-217 and miR -377, while miR-15 was up-regulated in the remnant kidney. In vitro, in tubular epithelial cells (NRK-52E), paclitaxel also inhibited TGF-ß1-induced Smad2/3 activation and normalized ILK, COL(I)A1, COL(IV)A2 and α-SMA expression. Furthermore, ChIP analyses indicated that Taxol suppressed Smad3-mediated miR-192 transcriptional activity. Over-expression of miR-192 in NRK-52E mimicked the changes seen in the remnant kidney, while inclusion of miR-192 inhibitor in the culture medium blocked TGF-ß1-induced COL(I)A1 and COL(IV)A2 expression, while ILK and α-SMA were unaffected. These data suggest that low-dose paclitaxel ameliorates renal fibrosis via modulating miR-192 pathobiology and TGF-ß/Smad signalling.