Label-free quantitative proteomic analysis of right ventricular remodeling in infant Tetralogy of Fallot patients

Changes in glutamic oxaloacetic transaminase 2 during rat physiological and pathological cardiomyocyte hypertrophy

BACKGROUND

Physiological and pathological cardiomyocyte hypertrophy are important pathophysiological processes of adult congenital heart disease-associated ventricular hypertrophy. Glutamic oxaloacetic transaminase (GOT) is a vital marker of myocardial injury. This study aimed to investigate the changes in GOT levels during physiological and pathological cardiomyocyte hypertrophy in rats.

METHODS

RNA-seq analysis and colorimetric methods were used to evaluate the changes in GOT mRNA and activity, respectively. GOT2 protein expression was detected by western blotting and immunofluorescence. Hematoxylin-eosin and wheat germ agglutinin methods were used to observe changes in rat cardiomyocyte morphology.

RESULTS

In juvenile rat hearts, GOT mRNA expression and activity, and GOT2 protein level increased with age-related physiological cardiomyocyte hypertrophy; however, GOT2 protein level was reduced in hypoxia-induced pathological cardiomyocyte hypertrophy.

CONCLUSIONS

GOT2 may regulate physiological and pathological myocardial hypertrophy in rats. We speculated that the low GOT2 level contributed to the rapid occurrence of pathological cardiomyocyte hypertrophy, causing strong plasticity of right ventricular cardiomyocytes in the early postnatal period and heart failure in adulthood.

Plasma metabolic profiling of patients with tetralogy of fallot

BACKGROUND

Tetralogy of Fallot (TOF) is a common congenital heart disease with high mortality. However, the medical imageology and liquidbiopsy techniques present certain limitations. Thus, this study investigated the plasma metabolic profiles to distinguish key metabolites for early diagnosis of TOF.

METHODS

In total, 69 patients with TOF and 43 normal controls were enrolled for targeted metabolomics based on liquid chromatography-tandem mass spectroscopy (LC-MS/MS). Absolute quantification of metabolites was performed using our standard database. The differentially expressed metabolites (DEMs) were screened by fold change (FC), VIP value and pearson correlation coefficient of OPLS-DA model. Receiver operating characteristic curve (ROC) was used to evaluate predictive ability of DEMs.

RESULTS

Different metabolic profiles were presented between TOF and Normal.The pathway analysis showed that significantly changed metabolites were enriched in nicotinamide and purine metabolism. Many intermediatesproductof purine and amido acid were higher in TOF than in Normal group, while energy substrates and electron carriers were lower in TOF than in Normal group. ROC analysis revealed a high diagnostic value of plasma FAD for differentiating TOF from Normal (AUC = 1).

CONCLUSION

Our study quantitatively characterized plasma metabolites in patients with TOF and may help to develop reliable biomarkers that contribute to the early TOF screening.

The right ventricle in tetralogy of Fallot: adaptation to sequential loading

Right ventricular dysfunction is a major determinant of outcome in patients with complex congenital heart disease, as in tetralogy of Fallot. In these patients, right ventricular dysfunction emerges after initial pressure overload and hypoxemia, which is followed by chronic volume overload due to pulmonary regurgitation after corrective surgery. Myocardial adaptation and the transition to right ventricular failure remain poorly understood. Combining insights from clinical and experimental physiology and myocardial (tissue) data has identified a disease phenotype with important distinctions from other types of heart failure. This phenotype of the right ventricle in tetralogy of Fallot can be described as a syndrome of dysfunctional characteristics affecting both contraction and filling. These characteristics are the end result of several adaptation pathways of the cardiomyocytes, myocardial vasculature and extracellular matrix. As long as the long-term outcome of surgical correction of tetralogy of Fallot remains suboptimal, other treatment strategies need to be explored. Novel insights in failure of adaptation and the role of cardiomyocyte proliferation might provide targets for treatment of the (dysfunctional) right ventricle under stress.

Circular Network of Coregulated Sphingolipids Dictates Chronic Hypoxia Damage in Patients With Tetralogy of Fallot

Background: Tetralogy of Fallot (TOF) is the most common cyanotic heart disease. However, the association of cardiac metabolic reprogramming changes and underlying molecular mechanisms in TOF-related chronic myocardial hypoxia damage are still unclear.

Methods: In this study, we combined microarray transcriptomics analysis with liquid chromatography tandem-mass spectrometry (LC–MS/MS) spectrum metabolomics analysis to establish the metabolic reprogramming that occurs in response to chronic hypoxia damage. Two Gene Expression Omnibus (GEO) datasets, GSE132176 and GSE141955, were downloaded to analyze the metabolic pathway in TOF. Then, a metabolomics analysis of the clinical samples (right atrial tissue and plasma) was performed. Additionally, an association analysis between differential metabolites and clinical phenotypes was performed. Next, four key genes related to sphingomyelin metabolism were screened and their expression was validated by real-time quantitative PCR (QT-PCR).

Results: The gene set enrichment analysis (GSEA) showed that sphingolipid metabolism was downregulated in TOF and the metabolomics analysis showed that multiple sphingolipids were dysregulated. Additionally, genes related to sphingomyelin metabolism were identified. We found that four core genes, UDP-Glucose Ceramide Glucosyltransferase (UGCG), Sphingosine-1-Phosphate Phosphatase 2 (SGPP2), Fatty Acid 2-Hydroxylase (FA2H), and Sphingosine-1-Phosphate Phosphatase 1 (SGPP1), were downregulated in TOF.

Conclusion: Sphingolipid metabolism was downregulated in TOF; however, the detailed mechanism needs further investigation.

Integration of Transcriptomic and Proteomic Data Reveals the Possible Action Mechanism of the Antimicrobial Zhongshengmycin Against Didymella segeticola, the Causal Agent of Tea Leaf Spot

Tea leaf spot, caused by the fungal phytopathogen Didymella segeticola, is an important foliar disease that can cause huge losses in the production and quality of tea, and there are no effective management measures to control the disease. This study screened a natural antimicrobial chemical for its activity against D. segeticola and studied its mode of action. Antifungal activity of the Streptomyces-derived antimicrobial zhongshengmycin (ZSM) against D. segeticola strain GZSQ-4 was assayed in vitro via the mycelial growth rate method. Optical microscopy and scanning and transmission electron microscopy were used to observe the morphological effects on hyphae treated with ZSM, with these studies complemented by transcriptomic, proteomic, and bioinformatic studies to identify the differentially expressed genes or differentially expressed proteins in hyphae treated with ZSM. Correlation analysis of transcriptomic and proteomic data were used to reveal the mode of action. The results indicated that ZSM could inhibit the growth of hyphae in vitro with a half-maximal effective concentration of 5.9 μg/ml, inducing some morphological changes in organelles, septa, and extracellular polysaccharides, targeting ribosomes to disturb translation, affecting the biosynthesis of some hyphal proteins at the messenger RNA and protein levels, and revealing correlations between findings from transcriptomes and proteomes.

Restoring mitochondrial superoxide levels with elamipretide (MTP-131) protects db/db mice against progression of diabetic kidney disease

Exposure to chronic hyperglycemia because of diabetes mellitus can lead to development and progression of diabetic kidney disease (DKD). We recently reported that reduced superoxide production is associated with mitochondrial dysfunction in the kidneys of mouse models of type 1 DKD. We also demonstrated that humans with DKD have significantly reduced levels of mitochondrion-derived metabolites in their urine. Here we examined renal superoxide production in a type 2 diabetes animal model, the db/db mouse, and the role of a mitochondrial protectant, MTP-131 (also called elamipretide, SS-31, or Bendavia) in restoring renal superoxide production and ameliorating DKD. We found that 18-week-old db/db mice have reduced renal and cardiac superoxide levels, as measured by dihydroethidium oxidation, and increased levels of albuminuria, mesangial matrix accumulation, and urinary H2O2 Administration of MTP-131 significantly inhibited increases in albuminuria, urinary H2O2, and mesangial matrix accumulation in db/db mice and fully preserved levels of renal superoxide production in these mice. MTP-131 also reduced total renal lysocardiolipin and major lysocardiolipin subspecies and preserved lysocardiolipin acyltransferase 1 expression in db/db mice. These results indicate that, in type 2 diabetes, DKD is associated with reduced renal and cardiac superoxide levels and that MTP-131 protects against DKD and preserves physiological superoxide levels, possibly by regulating cardiolipin remodeling.

Proteomics analysis indicated the protein expression pattern related to the development of fetal conotruncal defects

Abnormal development of embryonic conus arteriosus could lead to conotruncal defects in fetal heart, and increase the incidence of fetal congenital heart disease. Tetralogy of Fallot (TOF) is one of the most common forms of congenital heart disease. It may be helpful for us to solve this clinical problem through exploring the molecular mechanisms of development in embryonic congenital heart disease. Proteomics has attracted much attention in understanding the development of human diseases during the past decades. However, there is still little information about the relationship between protein expression pattern and TOF. In this study, we aimed to explore the potential linkage of proteomics and TOF development. Briefly, 121 differentially expressed proteins were identified from a TOF group, compared with a control group. The expression levels of 34 of these proteins were significantly different (>1.5 absolute fold change, p < 0.05) between the two groups. Gene ontology (GO) and pathway analysis showed that these proteins were mainly associated with carbon metabolism, biosynthesis of antibodies, positive regulation of transcription from RNA polymerase II promoter, nucleus, ATP binding, and so on. The ingenuity pathway analysis (IPA) results indicated that 435 of upstream regulators were identified of these differentially expressed proteins, which might be involved in the development of TOF. Data of string analysis showed the protein-protein interaction network among the differentially expressed proteins and regulators, which are related to TOF. In conclusion, our study explored the protein expression pattern of TOF, which might provide new insights into understanding the mechanism of TOF development and afford potential targets for TOF diagnosis and therapy.

Investigating the antifungal activity and mechanism of a microbial pesticide Shenqinmycin against Phoma sp

Tea white scab (TWS) is a major disease affecting tea trees in mid-elevation regions and often occurs during rainy seasons with low temperatures. This disease is caused by the fungal pathogen Phoma sp. TWS can infect young stems, tender leaves, and tender shoots and lead to the production of low-quality tea. Owing to the absence of an effective control, TWS can result in substantial loss in tea production. In this study, we isolated and identified the pathogen from tea leaves infected by TWS and then evaluated in vitro the antifungal activity of Shenqinmycin, polyoxin, azoxystrobin, oligosaccharins, and tebuconazole against Phoma sp. Our results indicated that Shenqinmycin can inhibit the growth of Phoma sp. mycelia, with the EC₅₀ value of 0.74μg/mL. After Phoma sp. being incubated in PDB liquid medium with Shenqinmycin, its mycelia were distorted and distended at 1.56μg/mL of minimum inhibitory concentration for 6h. Crucial genes associated with cell redox homeostasis, proteins synthesis, energy metabolism, and cytoskeleton were studied at mRNA and protein levels through RT-qPCR and Nano-LC-MS/MS. The results showed that the genes of 3-phosphate-glyceraldehyde dehydrogenase, citrate synthase, NADH-ubiquinone oxidoreductase subunit (NADH-subunit), ribosomal protein, eukaryotic initiation factor 4A-I, β-tubulin, and α-tubulin were up-regulated. Meanwhile, the genes of formate dehydrogenase (FDH), malate dehydrogenase, mitochondrial heat shock protein, and protein disulfide-isomerase (PDI) were up-regulated at mRNA level but down-regulated at protein level. These results indicated that Shenqinmycin contribute to cell redox homeostasis by up- or down-regulating NADH-subunit, FDH, and PDI.

Potential association of long noncoding RNA HA117 with tetralogy of Fallot

Tetralogy of Fallot (TOF) is a congenital heart disease characterized by abnormal cardiomyocyte differentiation in the right ventricular outflow tract (RVOT), and HA117 is a novel long noncoding RNA (lncRNA) with anti-differentiation roles. To investigate the potential association of HA117 with TOF, we collected 84 RVOT tissues from patients with TOF. We determined the expression of HA117 in RVOT samples from TOF patients and collected clinical data to conduct a cross-sectional and short-term follow-up study. McGoon ratio, Nakata index, and left ventricular end-diastolic volume index (LVEDVI) were negatively correlated with the expression of HA117 based on subgroup analysis, correlation analysis and logistic regression analysis. Additionally, cardiopulmonary bypass (CPB) time and ICU stay were longer in patients with higher expression of HA117 than in patients with lower expression of HA117. Furthermore, percentage improvement in SPO₂ was significantly reduced in patients with increased HA117 expression at 6 months after surgery. Our results suggested that the increased expression of the novel lncRNA HA117 is a risk factor for unfavorable McGoon ratio, Nakata index and LVEDVI in TOF patients. Additionally, an increased expression of HA117 might lead to adverse short-term outcomes in TOF patients.

Evaluation of Rice Resistance to Southern Rice Black-Streaked Dwarf Virus and Rice Ragged Stunt Virus through Combined Field Tests, Quantitative Real-Time PCR, and Proteome Analysis

Diseases caused by southern rice black-streaked dwarf virus (SRBSDV) and rice ragged stunt virus (RRSV) considerably decrease grain yield. Therefore, determining rice cultivars with high resistance to SRBSDV and RRSV is necessary. In this study, rice cultivars with high resistance to SRBSDV and RRSV were evaluated through field trials in Shidian and Mangshi county, Yunnan province, China. SYBR Green I-based quantitative real-time polymerase chain reaction (qRT-PCR) analysis was used to quantitatively detect virus gene expression levels in different rice varieties. The following parameters were applied to evaluate rice resistance: acre yield (A.Y.), incidence of infected plants (I.I.P.), virus load (V.L.), disease index (D.I.), and insect quantity (I.Q.) per 100 clusters. Zhongzheyou1 (Z1) and Liangyou2186 (L2186) were considered the most suitable varieties with integrated higher A.Y., lower I.I.P., V.L., D.I. and I.Q.

FEATURES

In order to investigate the mechanism of rice resistance, comparative label-free shotgun liquid chromatography tandem-mass spectrometry (LC-MS/MS) proteomic approaches were applied to comprehensively describe the proteomics of rice varieties' SRBSDV tolerance. Systemic acquired resistance (SAR)-related proteins in Z1 and L2186 may result in the superior resistance of these varieties compared with Fengyouxiangzhan (FYXZ).

Age-Dependent Oxidative DNA Damage Does Not Correlate with Reduced Proliferation of Cardiomyocytes in Humans

BACKGROUND

Postnatal human cardiomyocyte proliferation declines rapidly with age, which has been suggested to be correlated with increases in oxidative DNA damage in mice and plays an important role in regulating cardiomyocyte proliferation. However, the relationship between oxidative DNA damage and age in humans is unclear.

METHODS

Sixty right ventricular outflow myocardial tissue specimens were obtained from ventricular septal defect infant patients during routine congenital cardiac surgery. These specimens were divided into three groups based on age: group A (age 0-6 months), group B (age, 7-12 months), and group C (>12 months). Each tissue specimen was subjected to DNA extraction, RNA extraction, and immunofluorescence.

RESULTS

Immunofluorescence and qRT-PCR analysis revealed that DNA damage markers-mitochondrial DNA copy number, oxoguanine 8, and phosphorylated ataxia telangiectasia mutated-were highest in Group B. However immunofluorescence and qRT-PCR demonstrated that two cell proliferation markers, Ki67 and cyclin D2, were decreased with age. In addition, wheat germ agglutinin-staining indicated that the average size of cardiomyocytes increased with age.

CONCLUSIONS

Oxidative DNA damage of cardiomyocytes was not correlated positively with age in human beings. Oxidative DNA damage is unable to fully explain the reduced proliferation of human cardiomyocytes.

Elevated NCX1 and NCKX4 expression in the patent postnatal ductus arteriosus of ductal-dependent congenital heart disease patients

Patency of the ductus arteriosus (DA) after birth is essential in ductal-dependent congenital heart disease. The Na(+)/Ca(2+) exchanger (NCX) has been demonstrated to play a key role in regulating vascular tone. The potassium-dependent Na(+)/Ca(2+) exchanger (NCKX) is a related family of NCX depending on the K(+) gradients which triggers DA constriction. The present study investigated the comparative expression of NCX and NCKX between a constricted DA and patent DA in human ductal-dependant congenital heart disease. Human DAs, which were patent (n = 10, age = 20.2 ± 4.3 days) or constricted (n = 10, age = 18.3 ± 3.9 days), were excised during surgery from neonates with ductal-dependent congenital heart disease. Western blotting analysis, real-time quantitative polymerase chain reaction analysis and immunofluorescence studies were performed to detect the protein and mRNA levels of NCX1, NCKX3, and NCKX4. The expressions of NCX1 and NCKX4 were significantly higher in the patent DA group at both the protein and mRNA levels, and expression was localized to the smooth muscle layer. These findings indicate that NCX1 and NCKX4 are up-regulated in human postnatal patent DAs and may represent potential therapeutic targets for maintaining DA patency in ductal-dependent congenital heart disease.

Global gene expression profiling identifies new therapeutic targets in acute Kawasaki disease

Background

Global gene expression profiling can provide insight into the underlying pathophysiology of disease processes. Kawasaki disease (KD) is an acute, self-limited vasculitis whose etiology remains unknown. Although the clinical illness shares certain features with other pediatric infectious diseases, the occurrence of coronary artery aneurysms in 25% of untreated patients is unique to KD.

Methods

To gain further insight into the molecular mechanisms underlying KD, we investigated the acute and convalescent whole blood transcriptional profiles of 146 KD subjects and compared them with the transcriptional profiles of pediatric patients with confirmed bacterial or viral infection, and with healthy control children. We also investigated the transcript abundance in patients with different intravenous immunoglobulin treatment responses and different coronary artery outcomes.

Results

The overwhelming signature for acute KD involved signaling pathways of the innate immune system. Comparison with other acute pediatric infections highlighted the importance of pathways involved in cell motility including paxillin, relaxin, actin, integrins, and matrix metalloproteinases. Most importantly, the IL1β pathway was identified as a potential therapeutic target.

Conclusion

Our study revealed the importance of the IL-1 signaling pathway and a prominent signature of innate immunity and cell migration in the acute phase of the illness.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-014-0102-6) contains supplementary material, which is available to authorized users.