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

Nonalcoholic fatty liver disease (NAFLD) is a global health threat. Here, we presented the significant role of a novel signaling axis comprising long non-coding RNA maternally expressed gene 3 (MEG3), enhancer of zeste homolog 2 (EZH2), and sirtuin 6 (SIRT6) in controlling lipid accumulation, inflammation, and the progression of NAFLD. Mice fed with high-fat diet (HFD) were established as in vitro and in vivo NAFLD models, respectively. Lipid accumulation was measured by oil red O staining and assays for triglycerides or cholesterol. Inflammation was examined by ELISA for pro-inflammatory cytokines. Gene expressions were examined by RT-qPCR or Western blot. Interactions between key signaling molecules were examined by combining expressional analysis, RNA immunoprecipitation, cycloheximide stability assay, co-immunoprecipitation, and chromatin immunoprecipitation. MEG3 level was reduced in FFA-challenged hepatocytes or liver from HFD-fed mice, and the reduction paralleled the severity of NAFLD in clinic. Overexpressing MEG3 suppressed FFA-induced lipid accumulation or inflammation in hepatocytes. By promoting the ubiquitination and degradation of EZH2, MEG3 upregulated SIRT6, an EZH2 target. SIRT6 essentially mediated the protective effects of MEG3 in hepatocytes. Consistently, overexpressing MEG3 alleviated HFD-induced NAFLD in vivo. By controlling the expressions of genes involved in lipid metabolism and inflammation, the MEG3/EZH2/SIRT6 axis significantly suppressed lipid accumulation and inflammation in vitro, and NAFLD development in vivo. Therefore, boosting MEG3 level may benefit the treatment of NAFLD.

There is an urgent need to find reliable and rapid bovine tuberculosis (bTB) diagnostics in response to the rising prevalence of bTB worldwide. Toll-like receptor 2 (TLR2) recognizes components of bTB and initiates antigen-presenting cells to mediate humoral immunity. Evaluating the affinity of antigens with TLR2 can form the basis of a new method for the diagnosis of bTB based on humoral immunity.To develop a reliable and rapid strategy to improve diagnostic tools for bTB.In this study, we expressed and purified the sixteen bTB-specific recombinant proteins inThe results showed that interaction surface Cα-atom root mean square deviation of proteins (M1, M2, MPT70, MPT83)-TLR2 protein are less than 2.5 A, showing a high affinity. It is verified by clinical serum samples that MPT70, MPT83, MPT70-MPT83 showed good diagnostic potential for the detection of anti-bTB IgG and M1, M2 can replace the whole protein as the detection antigen.Molecular docking to evaluate the affinity of bTB protein and TLR2 combined with ELISA provides new insights for the diagnosis of bTB.

Background: Kawasaki Disease (KD) is an acute self-limiting systemic vasculitis syndrome which can result in arterial damage especially in coronary artery. To find possible new biomarkers for the diagnosis of KD by Data independent acquisition (DIA) quantitative proteomics.Methods: Twenty-seven patients with KD were enrolled in the present study, further, gingival crevicular fluid of before IVIG treatment with KD was collected as the experimental group. Meanwhile, 18 healthy volunteers were recruited as the control group.DIA quantitative proteomics mass spectrometry analysis was performed on the GCF samples of each group, and the protein expression profiles of the two groups of GCF were detected. Function enrichment of DEP by KEGG and GO, protein-protein interaction (PPI) analysis for all the DEPs detected, Finally, the multiple reaction monitoring mass spectrometry method was used to verify the selected DEPs.Results:197 DEPs (174 up-regulated and 23 down-regulated) were detected in the CGF between the KD group and the normal control group. Cellular process and metabolic process, binding and catalytic activity are the most altered biological process and molecular function, respectively. NOD−like receptor signaling pathway, Protein processing in endoplasmic reticulum pathway and influenza pathway are most significant pathway. EIF2AK2, B2M and GBP1 are kernel proteins in PPI network. The results of MRM-MS of 12 DEPs including IFIT3, UB2L6, HP, A1AT, HSP90AA1, HNRPC, HSP90AB1, SAA1, MX1, B2M, FKBP4 and TRAP1 were highly consistent with DIA.Conclusions: We suggested that 12 proteins in GCF could be used as new biomarkers for early diagnosis of KD. We also found that KD is closely related to gingival inflammation at the molecular level, which provides new ideas and directions for the diagnosis and treatment of KD.

Background: Kawasaki disease (KD) is an acute self-limiting systemic vasculitis. In study, a randomized controlled trial regarding berberine (main component of Coptidis Rhizoma) function in treating KD was carried out and possible pharmacological mechanisms of Coptidis Rhizoma (CR) on KD therapy were investigated using an integrated network pharmacology approach. Methods: A total of 58 children with KD, younger than 5 years old, were enrolled in the study from October 2018 to May 2019. The patients were randomly divided into control group and BBR treatment group. The therapeutic indicators of the 2 groups before and after treatments were compared. Then, compounds and drug targets of CR from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database, the SWISS database, the SEA database and the STITCH database were collected, and targeted KD genes were retrieved from the DisGeNET databases, the DrugBank databases and the GeneCards databases. The network pharmacology approach involved network construction, target prediction, and module analysis. KEGG pathway and GO enrichment analysis were performed to investigate the molecular mechanisms and pathways related to CR for KD treatments. Results: The berberine group was able to reduce the values of CRP, NLR and PLR significantly. Also, the effect of berberine improved the resistance rate of intravenous injection of gamma globulin significantly. In total, 9 compounds and 369 relative drug targets were collected from TCMSP, SWISS, SEA and STITCH database and 624 KD target genes were collected in DisGeNET, DrugBank and GeneCards database. The network analysis revealed that 41 targets might be the therapeutic targets of CR on KD, among which ATK1, RELA, SRC, CASP3 and MTOR ranked in top 5. Gene ontology enrichment analysis revealed that the reaction to bacteria-derived molecules and to lipopolysaccharide and the apoptosis process were the key biological procedures for CR treating KD. The KEGG pathway enrichment analysis pointed out that the four signaling pathways closely related to CR treating KD including age-rage signaling pathway, fluid shear stress and atherosclerosis, TNF signaling pathway and Toll-like receptor signaling pathway in diabetic complications. Conclusions: we concluded that the introduction of routine treatment combined with berberine in treating KD has advantages than routine treatment and can be considered as a preferred approach in KD. Network pharmacology showed that CR exerted the effect of prevention KD by regulating multi-targets and multi-components.

Background: Kawasaki disease (KD) leads to coronary artery damage and the etiology of KD is unknown. The present study was designed to explore the differentially expressed genes (DEGs) in KD serum-induced human coronary artery endothelial cells (HCAECs) by RNA-sequence (RNA-seq). Methods: HCAECs were stimulated with serum (15% (v/v)), which were collected from 20 healthy children and 20 KD patients, for 24 hours. DEGs were then detected and analyzed by RNA-seq and bioinformatics analysis. Results: The expression of SMAD1, SMAD6, CD34, CXCL1, PITX2, and APLN was validated by qPCR. 102 genes, 59 up-regulated and 43 down-regulated genes, were significantly differentially expressed in KD groups. GO enrichment analysis showed that DEGs were enriched in cellular response to cytokines, cytokine-mediated signaling pathway, and regulation of immune cells migration and chemotaxis. KEGG signaling pathway analysis showed that DEGs were mainly involved in cytokine−cytokine receptor interaction, chemokine signaling pathway, and TGF−β signaling pathway. Besides, the mRNA expression levels of SMAD1, SMAD6, CD34, CXCL1, and APLN in the KD group were significantly up-regulated compared with the normal group, while PITX2 was significantly down-regulated. Conclusion: 102 DEGs in KD serum-induced HCAECs were identified, and six new targets may be closely associated with the pathogenesis of KD.

Leigh syndrome (LS) is a rare, progressive, and fatal neurodegenerative disease that occurs mainly in infants and children. Neonatal LS has not yet been fully described.The study design was approved by the ethics review board of Shenzhen Children's Hospital.A 24-day-old full-term male infant presented with a 2-day history of lip cyanosis when crying in September 2021. He was born to nonconsanguineous Asian parents. After birth, the patient was fed poorly. A recurrent decrease in peripheral oxygen saturation and difficulty in weaning from mechanical ventilation during hospitalization were observed. There were no abnormalities on brain magnetic resonance imaging (MRI) or blood and urine organic acid analyses on admission. His lactic acid level increased markedly, and repeat MRI showed symmetrical abnormal signal areas in the bilateral basal ganglia and brainstem with disease progression. Trio whole-exome sequencing revealed 2 heterozygous mutations (c.64C T [p.R22X] and c.584T C [p.L195S]) in NDUFS1. Based on these findings, mitochondrial respiratory chain complex I deficiency-related LS was diagnosed. The patient underwent tracheal intubation and mechanical ventilation for respiratory failure. His oxygen saturation levels were maintained at normal levels with partially assisted ventilation. He was administered broad-spectrum antibiotics, oral coenzyme Q10, multivitamins, and idebenone. During hospitalization, the patient developed progressive consciousness impairment and respiratory and circulatory failure. He died on day 30.Lip cyanosis is an important initial symptom in LS. Mild upper respiratory tract infections can induce LS and aggravate the disease. No abnormal changes in the brain MRI were observed in the early LS stages in this patient. Multiple MRIs and blood lactic acid tests during disease progression and genetic testing are important for prompt and accurate diagnosis of LS.

Brucellosis is a highly contagious zoonotic disease, which seriously endangers animal husbandry in China. Bone marrow-derived dendritic cells (DCs) are full-time antigen presenting cells (APC) that play an important role in the interaction between pathogens and host immunity. DCs were stimulated with Brucella major outer membrane proteins (OMPs: OMP10, OMP19, OMP25, BP26 and OMP31) and Brucella mutants (Δ omp10, Δ omp19, Δ omp25, Δ bp26, Δ omp31) to examine effects on DC maturity and antigen presentation. Brucella OMP10, OMP19 and BP26; Brucella mutants Δ omp10, Δ omp19, Δ omp25, Δ bp26, Δ omp31 and Brucella RB51 induced DC maturation and antigen presentation efficiency in mice, activated proliferation of T lymphocytes, and decreased apoptosis, which helped the host recognize antigens and eliminate pathogens. However, B. abortus 2308 evaded the host immune function and established chronic infection by maintaining a balance between intracellular replication and inducing apoptosis, thus reducing DC maturation and antigen presentation to T cells. Toll-like receptor (TLR) -mediated signaling pathways were involved in the DC maturation and antigen presentation induced by Brucella OMPs. These results enhance understanding of Brucella pathogenesis and the host protective immune response mechanism and lay the foundation for the rational design of Brucella vaccines.

Altered Serine/Threonine phosphorylation of the cardiac proteome is an established hallmark of heart failure (HF). However, the contribution of tyrosine phosphorylation to the pathogenesis of these diseases remains unclear. The cardiac proteome was explored by global mapping to discover and quantify site-specific tyrosine phosphorylation in two cardiac hypertrophic models; cardiac overexpression of ErbB2 (TgErbB2) and cardiac expression of α-Myosin heavy chain R403Q (R403Q-αMyHCTg) compared to control hearts. Phosphoproteomic changes found in R403Q-αMyHC Tg mice indicated EGFR1, Focal Adhesion, VEGF, ErbB signaling, and Chemokine signaling pathways activity were likely to be activated. On the other hand, TgErbB2 mice findings displayed significant overrepresentation of Right Ventricular Cardiomyopathy, Hypertrophic Cardiomyopathy (HCM), and dilated cardiomyopathy (DCM) KEGG Pathways. In silico kinase-substrate enrichment analysis (KSEA) highlighted a marked downregulation of canonical MAPK Pathway Activity downstream of k-Ras in TgErbB2 mice and activation of EGFR, PP2 inhibition of c-Src, and Hepatocyte growth factor stimulation. In vivo ErbB2 inhibition by AG-825 decreased cardiac fibrosis, cardiomyocyte disarray, and rescued contractile function on TgErbB2 mice. These results suggest that altered tyrosine phosphorylation may play a regulatory role in cardiac hypertrophic models, suggesting that tyrosine kinase inhibitors could be used therapeutically in Hypertrophic Cardiomyopathy.

Alterations of serine/threonine phosphorylation of the cardiac proteome are a hallmark of heart failure. However, the contribution of tyrosine phosphorylation (pTyr) to the pathogenesis of cardiac hypertrophy remains unclear. We use global mapping to discover and quantify site-specific pTyr in two cardiac hypertrophic mouse models, i.e., cardiac overexpression of ErbB2 (TgErbB2) and α myosin heavy chain R403Q (R403Q-αMyHC Tg), compared to control hearts. From this, there are significant phosphoproteomic alterations in TgErbB2 mice in right ventricular cardiomyopathy, hypertrophic cardiomyopathy (HCM), and dilated cardiomyopathy (DCM) pathways. On the other hand, R403Q-αMyHC Tg mice indicated that the EGFR1 pathway is central for cardiac hypertrophy, along with angiopoietin, ErbB, growth hormone, and chemokine signaling pathways activation. Surprisingly, most myofilament proteins have downregulation of pTyr rather than upregulation. Kinase-substrate enrichment analysis (KSEA) shows a marked downregulation of MAPK pathway activity downstream of k-Ras in TgErbB2 mice and activation of EGFR, focal adhesion, PDGFR, and actin cytoskeleton pathways. In vivo ErbB2 inhibition by AG-825 decreases cardiomyocyte disarray. Serine/threonine and tyrosine phosphoproteome confirm the above-described pathways and the effectiveness of AG-825 Treatment. Thus, altered pTyr may play a regulatory role in cardiac hypertrophic models.

Background: Kawasaki disease (KD) isan acute self-limiting systemic vasculitis.In this study, a randomized controlled trial regarding berberine (main component of CoptidisRhizoma) function in treating KD was carried out and possible pharmacological mechanisms of CoptidisRhizoma (CR) on Kawasaki disease therapy were investigated using an integrated network pharmacology approach.Results: The BBR group was able to reduce the values of CRP, NLR and PLR significantly. Also, the effect of BBR improved the resistance rate of intravenous injection of gamma globulin significantly. In total, 9 compounds and 369 relative drug targets were collected from TCMSP, SWISS, SEA and STITCH database and 624 KD target genes were collected in DisGeNET, DrugBank and GeneCards database. The network analysis revealed that 41 targets might be the therapeutic targets of CR on KD, among which ATK1, RELA, SRC, CASP3 and MTOR ranked in top 5. Gene ontology enrichment analysis revealed that the reaction to bacteria-derived molecules and to lipopolysaccharide and the apoptosis process were the key biological procedures for CR treating KD. The KEGG pathway enrichment analysis pointed out that the four signaling pathways closely related to CR treating KD including age-rage signaling pathway, fluid shear stress and atherosclerosis, TNF signaling pathway and Toll-like receptor signaling pathway in diabetic complications.Conclusion: We concluded that the introduction of routine treatment combined with BBR in treating KD has advantages than routine treatment and can be considered as a preferred approach in KD. Network pharmacology showed that CR exerted the effect of prevention KD by regulating multi-targets and multi-components.

Foot-and-mouth disease (FMD) is a pathological disease caused by the foot- and-mouth disease virus (FMDV), which mainly affects cloven-hoofed animals. This study was conducted to a meta-analysis and experiment on the effect of bacteriophages used in the development of FMDV vaccines. A systematic search was conducted for the collection of the protection effect for the phage-based FMDV vaccine using sensitive search strategies. The extracted data were analyzed using Rev-Man 5.4 software. This experiment used the T7 phage to express the capsid protein VP1 of the OHM-02 strain, and the recombinant VP1 phage was termed OHM-T7. Antibodies and cytokines levels were assessed after immunizing BALB/C mice with OHM-T7. The results showed that a total of 115 articles were retrieved, and 4 of them met the inclusion criteria. There was no heterogeneity with I2 = 0%, 20% or 43%. We used a fixed-effect model for meta-analysis, and the results showed a protective effect on FMDV between the phage group and control group (PPP>0.05). After successfully obtained the ohm-t7 strain and immunized the mice, it could induce high levels of IFN-γ levels in mice with little effect on IL-4 levels. OHM-T7 could be used to detect antibodies produced by mice immunized with different FMDV antigens and produce high levels of anti-FMD antibodies. In summary, these results showed the potential of phage-based FMDV vaccines in FMDV prevention.

Kawasaki disease (KD) is an acute febrile illness characterized by systemic vasculitis especially in coronary arteries. Berberine (BBR) shows several beneficial effects on cardiovascular system. The present study is to investigate whether BBR exerts protective effect against KD-induced damage of human coronary artery endothelial cell (HCAECs) and the underlying mechanisms. HCAECs exposed to medium with 15% serum from KD patients or healthy volunteers for 24 h. Stimulated HCAECs were treated with vehicle (without BBR) and BBR (20 μM) for 24 h, the cell apoptosis, cell cycle, induction of intracellular reactive oxygen species (ROS) and protein expression were examined by flow cytometry and western blot. The KD-induced differentially expressed proteins in HCAECs were determined by quantitative proteomics. BBR inhibited HCAECs from apoptosis and arrested cell cycle at G0/G1 stage. BBR protected HCAECs from injury by inhibiting expression of THBD, vWF and EDN1. Bioinformatics analysis suggested that the oxidative and ER stress were involved in KD-induced damage in HCAECs. ROS production and the protein expression of ATF4, p-EIF2α, p-PERK, XBP1, p-IRE1, HSP90B1, HSPG2, DNAJC3, P4HB and VCP were increased by serum from KD patients and decreased by BBR treatment. BBR exerts its protective effects on KD-induced damage of HCAECs through its inhibitory effects on oxidative and ER stress indicating BBR as a therapeutic candidate for KD.

In the United States alone, ∼14,000 children are hospitalised annually with acute heart failure. The science and art of caring for these patients continues to evolve. The International Pediatric Heart Failure Summit of Johns Hopkins All Children’s Heart Institute was held on February 4 and 5, 2015. The 2015 International Pediatric Heart Failure Summit of Johns Hopkins All Children’s Heart Institute was funded through the Andrews/Daicoff Cardiovascular Program Endowment, a philanthropic collaboration between All Children’s Hospital and the Morsani College of Medicine at the University of South Florida (USF). Sponsored by All Children’s Hospital Andrews/Daicoff Cardiovascular Program, the International Pediatric Heart Failure Summit assembled leaders in clinical and scientific disciplines related to paediatric heart failure and created a multi-disciplinary “think-tank”. The purpose of this manuscript is to summarise the lessons from the 2015 International Pediatric Heart Failure Summit of Johns Hopkins All Children’s Heart Institute, to describe the “state of the art” of the treatment of paediatric cardiac failure, and to discuss future directions for research in the domain of paediatric cardiac failure.

In this work, Percolator was successfully interfaced with X!Tandem using a PHP program to generate an improved search platform, X!Tandem Percolator. In order to achieve the best classification performance of peptide identifications in Percolator, a set of experimentally validated spectral identifications (34,993 MS/MS spectra) were used to guide the development of discriminatory features from X!Tandem search results. By comparing the features (e.g., Log(E) and mass error) of these experimentally validated peptide matches with those of false identifications, a comprehensive set of features can be chosen for Percolator in an objective and rational manner. The accuracy of X!Tandem Percolator was demonstrated by comparing the estimated q-value of the validated data set with the empirical q-value. By comparing the results from the X!Tandem Percolator and the original X!Tandem, superior sensitivity and specificity of the X!Tandem Percolator result was demonstrated on various shotgun proteomic data sets under different search conditions. In all of the cases studied in this work, X!Tandem Percolator could improve the number of peptide identifications at the same level of q-values.

Data have shown that circulating endothelial progenitor cells (EPCs) closely correlate with the vascular endothelial layer state. The present study was designed to describe the evolution of EPCs in children before and 24 h after transcatheter closure surgery for occluding congenital heart disease. Three groups of patients were studied: the transcatheter closure of atrial septal defect (ASD) group (group 1), the transcatheter closure of patent ductus arteriosus (PDA) group (group 2), and the transcatheter closure of ventricular septal defect (VSD) group (group 3). The circulating EPC level was detected using flow cytometry measuring CD34 and kinase insert receptor double-positive mononuclear cells. The concentration of vascular endothelial growth factor (VEGF) was assessed by enzyme-linked immunosorbent assay. The fluoroscopy time was correctly recorded during the surgery. All of the data were collected before and 24 h after surgery. EPC level and VEGF concentration did not change significantly before and at 24 h after surgery in groups 1 and 2. In group 3, the level of circulating EPCs and VEGF concentration increased significantly 24 h after surgery. The fluoroscopy time in group 3 was significantly longer than in groups 1 and 2. The increased volume of EPCs and VEGF were positively correlated in group 3. Our results showed that transcatheter closure of PDA and ASD in children does not lead to increased circulating level of EPCs. Transcatheter closure of VSD may result in vascular endothelium injury as indicated by increased circulating EPC level.

Multiple reaction monitoring (MRM) is a powerful proteomic technique that is hypothesis driven. MRM is gaining increasing attention among cardiovascular researchers because it has begun to provide mechanistic insights into heart failure and cardiomyopathies, and promises to develop into assays for clinical management. In this chapter we provide an overlook at the background of MRM considering basic principles of proteomics workflows, instrumentation and basic MRM assay design and compare it to shotgun proteomics. As case studies we highlight how MRM has been successfully employed to quantify myofilament post-translational modifications, more specifically phosphorylation of cardiac Troponin I, myofilament mutants replacement in cardiomyopathies and as a potential biomarker detection pipeline in heart failure.

A shotgun proteome analysis method and its performance for protein identification from 500 to 5000 cells are described. Sample preparation, which was done in one tube, involved the use of a surfactant (NP-40) for cell lysis, followed by acetone precipitation of the proteins. The resulting protein pellet was washed with cold acetone to remove remaining surfactant, and the pellet was then solubilized in NH(4)HCO(3). After trypsin digestion of the proteins, the digest was analyzed by the use of nanoflow liquid chromatography (LC) quadrupole time-of-flight mass spectrometry (QTOF MS). Sample injection and gradient speed in running LC QTOF MS were optimized. It was shown that this method could identify an average (n = 3) of 167 +/- 21, 237 +/- 30, 491 +/- 63, and 619 +/- 59 proteins from 500, 1000, 2500, and 5000 MCF-7 breast cancer cells, respectively. To demonstrate the potential use of this method for generating proteome profile from circulating tumor cells (CTCs) isolated from human blood, a healthy human blood sample was spiked with MCF-7 cells, and this mixture was processed and then subjected to antibody tagging of the MCF-7 cells. The tagged cells were sorted and collected using flow cytometry. The proteome profiles of small numbers of cells isolated in this way were found to be similar to those of the original MCF-7 cells, suggesting the possibility of the use of this method for cell typing of CTCs.

Heart failure in children is a complex clinical syndrome with multiple aetiologies. The underlying disorders that lead to heart failure in children differ significantly from those in adults. Some clinical biomarkers for heart failure status and prognosis appear to be useful in both age groups. This review outlines the use and the present status of biomarkers for heart failure in paediatric cardiology. Furthermore, clinical scenarios in which development of new biomarkers might address management or prognosis are discussed. Finally, strategies for proteomic discovery of novel biomarkers and application to practice are described.

Objectives: Tyrosine (Tyr) phosphorylation of the myofilament is an emerging, and potentially important, post-translational modification in cardiomyopathy. ErbB2, a Tyr receptor kinase, was overexpressed in transgenic mice (ErbB2-Tg) resulting in significant cardiac hypertrophy. We hypothesize that the development of cardiac hypertrophy in ErbB2-Tg is associated with increased myofilament Tyr phosphorylation and may implicate myofilament Tyr phosphorylation in cardiac hypertrophy. Methods: Proteins were isolated from ErbB2-Tg and Ntg heart homogenates ( n =4 per group). Reduction/alkylation was followed by trypsinization. Resulting peptides were desalted in C 18 columns and lyophilized. Phosphorylated Tyr (p-Tyr) enrichment was performed on 20 mg of peptides using a p-Tyr Mouse mAb kit (Cell Signaling). Immuno-precipitated and desalted peptides were analyzed by LC-MS/MS (Orbitrap Elite, Thermo). Raw data were searched with Mascot 2.3. Label-free quantification with MS1 extracted ion chromatograms was performed using Skyline. Western blot analysis for total and phosphorylated Src kinase was performed per manufacturer’s protocol (Cell Signaling). Results: We found a total of 286 p-Tyr modified peptides in ErbB2-Tg compared to 226 in control NTg mice. Over 70 p-Tyr sites on myofilament protein were up-regulated in ErbB2-Tg, including troponin I, myosin heavy chain, titin, α-tropomyosin, myosin-binding protein-C3, myosin regulatory light chain-2 and myosin light chain-1. We used PhosphoMotif Finder to search the potential responsible kinase. Most of the p-Tyr sites were consistent with Src kinase motifs. Furthermore, Western blot analysis showed that total, and phospho-Src (Y416) expression was increased in ErbB2-Tg mice. Conclusion: We concluded that these novel p-Tyr sites on myofilament proteins are increased in ErbB2-Tg mice and correlate with up-regulated Src kinase activity. Thus increased tyrosine myofilament phosphorylation may be involved in the development of cardiac hypertrophy. Since ErbB2 is a therapeutic target of trastuzumab therapy this may also have translational implications to ameliorate off target effects of cancer treatment.

Contractile dysfunction and increased deposition of O-linked β-N-acetyl-d-glucosamine (O-GlcNAc) in cardiac proteins are a hallmark of the diabetic heart. However, whether and how this posttranslational alteration contributes to lower cardiac function remains unclear. Using a refined β-elimination/Michael addition with tandem mass tags (TMT)–labeling proteomic technique, we show that CpOGA, a bacterial analog of O-GlcNAcase (OGA) that cleaves O-GlcNAc in vivo, removes site-specific O-GlcNAcylation from myofilaments, restoring Ca2+ sensitivity in streptozotocin (STZ) diabetic cardiac muscles. We report that in control rat hearts, O-GlcNAc and O-GlcNAc transferase (OGT) are mainly localized at the Z-line, whereas OGA is at the A-band. Conversely, in diabetic hearts O-GlcNAc levels are increased and OGT and OGA delocalized. Consistent changes were found in human diabetic hearts. STZ diabetic hearts display increased physical interactions of OGA with α-actin, tropomyosin, and myosin light chain 1, along with reduced OGT and increased OGA activities. Our study is the first to reveal that specific removal of O-GlcNAcylation restores myofilament response to Ca2+ in diabetic hearts and that altered O-GlcNAcylation is due to the subcellular redistribution of OGT and OGA rather than to changes in their overall activities. Thus, preventing sarcomeric OGT and OGA displacement represents a new possible strategy for treating diabetic cardiomyopathy.

We report an isotope labeling shotgun proteome analysis strategy to validate the spectrum-to-sequence assignments generated by using sequence-database searching for the construction of a more reliable MS/MS spectral library. This strategy is demonstrated in the analysis of the E. coli K12 proteome. In the workflow, E. coli cells were cultured in normal and (15)N-enriched media. The differentially labeled proteins from the cell extracts were subjected to trypsin digestion and two-dimensional liquid chromatography quadrupole time-of-flight tandem mass spectrometry (2D-LC QTOF MS/MS) analysis. The MS/MS spectra of the two samples were individually searched using Mascot against the E. coli proteome database to generate lists of peptide sequence matches. The two data sets were compared by overlaying the spectra of unlabeled and labeled matches of the same peptide sequence for validation. Two cutoff filters, one based on the number of common fragment ions and another one on the similarity of intensity patterns among the common ions, were developed and applied to the overlaid spectral pairs to reject the low quality or incorrectly assigned spectra. By examining 257,907 and 245,156 spectra acquired from the unlabeled and (15)N-labeled samples, respectively, an experimentally validated MS/MS spectral library of tryptic peptides was constructed for E. coli K12 that consisted of 9,302 unique spectra with unique sequence and charge state, representing 7,763 unique peptide sequences. This E. coli spectral library could be readily expanded, and the overall strategy should be applicable to other organisms. Even with this relatively small library, it was shown that more peptides could be identified with higher confidence using the spectral search method than by sequence-database searching.

In this study, the peripheral blood mononuclear cells of healthy adult were acquired and inducted by vascular endothelial growth factor, et cetera. The differentiated endothelial cells were observed and identified as EPCs by the double positive staining of fluorescent labeled acetylated-LDL and lectin, seeded on the polyurethane small-diameter artificial vessels, treated by shear stress of 15 dyn/cm2, and observed by scanning electronic microscopy. As a result, the peripheral blood mononuclear cells differentiated into EPCs. They were positively stained by labeled acetylated-LDL and lectin. Under observation of scanning electronic microscope, the unseeded polyurethane small-diameter artificial vessel being suited for the growth and spreading of the cells; the cell lineage on surface of artificial vessels of stationary group being arrayed in chaos, and that of shear stress group being arrayed in direction. Therefore, the peripheral cells can differentiate into EPCs, and EPCs can be used as novel source cells for the accelerated endothelialization of small diameter artificial vessel. Shear stress contributes to the mechanic moulding of cell lineage on the surface of artificial vessel.