scholarly journals Peptidomic Analysis of Cultured Cardiomyocytes Exposed to Acute Ischemic-Hypoxia

2017 ◽  
Vol 41 (1) ◽  
pp. 358-368 ◽  
Author(s):  
Lijie Wu ◽  
Hua Li ◽  
Xing Li ◽  
Yumei Chen ◽  
Qijun Zhang ◽  
...  
Keyword(s):  
Neonatal Rat ◽  
Tandem Mass ◽  
Myocardial Cells ◽  
Functional Studies ◽  
Ischemic Hypoxia ◽  
Tandem Mass Tag ◽  
Life Threatening ◽  
Peptidomic Analysis ◽  
Cultured Cardiomyocytes ◽  
Peptidomic Profiling

Background: Acute Myocardial Infarction (AMI) is a life-threatening cardiovascular disease involving disruption of blood flow to the heart, consequent tissue damage, and sometimes death. Peptidomics, an emerging branch of proteomics, has attracted wide attention. Methods: A comparative peptidomic profiling was used to explore changes induced by acute ischemic-hypoxia in primary cultured neonatal rat myocardial cells. Analysis of six-plex tandem mass tag (TMT) labelled peptides was performed using nanoflow liquid chromatography coupled online with an LTQ-Orbitrap Velos mass spectrometer. Results: A total of 220 differentially expressed peptides originating from 119 proteins were identified, of which 37 were upregulated and 183 were downregulated in cardiomyocytes exposed to hypoxia/ischemia conditions. Many of the identified peptides were derived from functional domains of proteins closely associated with cardiomyocyte structure or AMI. Conclusion: Numerous peptides may be involved in process of AMI. These results pave the way for future functional studies of the identified peptides.

scholarly journals Optogenetic currents in myofibroblasts acutely alter electrophysiology and conduction of co-cultured cardiomyocytes

2020 ◽  
Author(s):  
Geran Kostecki ◽  
Yu Shi ◽  
Christopher Chen ◽  
Daniel H. Reich ◽  
Emilia Entcheva ◽  
...  
Keyword(s):  
Cardiac Tissue ◽  
Cardiac Injury ◽  
Neonatal Rat ◽  
Culture Studies ◽  
Electrophysiological Properties ◽  
Inward Currents ◽  
Life Threatening ◽  
Cultured Cardiomyocytes ◽  
Cardiac Myofibroblasts

AbstractInteractions between cardiac myofibroblasts and myocytes may slow conduction after cardiac injury, increasing the chance of life-threatening arrhythmia. While co-culture studies have shown that myofibroblasts can affect cardiomyocyte electrophysiology in vitro, the mechanism(s) remain debatable. In this study, primary neonatal rat cardiac myofibroblasts were transduced with the light-activated ion channel Channelrhodopsin-2, which allowed acute and selective modulation of myofibroblast currents in co-cultures with cardiomyocytes. Optical mapping revealed that myofibroblast-specific optogenetically induced inward currents decreased conduction velocity in the co-cultures by 27±6% (baseline = 17.7±5.3 cm/s), and shortened the cardiac action potential duration by 14±7% (baseline = 161±11 ms) when 0.017 mW/mm2 light was applied. When light irradiance was increased to 0.057 mW/mm2, the myofibroblast currents led to spontaneous beating in 6/7 co-cultures. Experiments showed that optogenetic perturbation did not lead to changes in myofibroblast strain and force generation, suggesting purely electrical effects in this model. In silico modeling of optogenetically modified myofibroblast-cardiomyocyte co-cultures largely reproduced these results and enabled a comprehensive study of relevant parameters. These results clearly demonstrate that myofibroblasts are sufficiently electrically connected to cardiomyocytes to effectively alter macroscopic electrophysiological properties in this model of cardiac tissue.

Identification of novel autoantibodies in ascites of relapsed paclitaxel-resistant gastric cancer with peritoneal metastasis using immunome protein microarrays and proteomics

2021 ◽  
pp. 1-10
Author(s):  
Zhongyin Yang ◽  
Chao Yan ◽  
Wentao Liu ◽  
Wei Xu ◽  
Chen Li ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Effective Treatment ◽  
Peritoneal Metastasis ◽  
Quantitative Proteomics ◽  
Poor Prognosis ◽  
Protein Microarrays ◽  
Tandem Mass ◽  
Tandem Mass Tag ◽  
Resistant Group ◽  
Potential Biomarkers

BACKGROUND: Gastric cancer (GC) patients with peritoneal metastasis usually have extremely poor prognosis. Intraperitoneal infusion of paclitaxel (PTX) provides an effective treatment, but relapse and PTX-resistance are unavoidable disadvantages, and it is difficult to monitor the occurrence of PTX-resistance. OBJECTIVE: The aim of this study was to explore novel autoantibodies in the ascites of individuals with relapsed PTX-resistant GC with peritoneal metastasis. METHODS: Ascites samples were collected before PTX infusion and after the relapse in 3 GC patients. To determine the expression of significantly changed proteins, we performed autoantibody profiling with immunome protein microarrays and tandem mass tag (TMT) quantitative proteomics, and then, the overlapping proteins were selected. RESULTS: Thirty-eight autoantibodies that were differentially expressed between the ascites in the untreated group and relapsed PTX-resistant group were identified. For confirmation of the results, TMT quantitative proteomics was performed, and 842 dysregulated proteins were identified. Four proteins, TPM3, EFHD2, KRT19 and vimentin, overlapped between these two assays. CONCLUSIONS: Our results first revealed that TPM3, EFHD2, KRT19 and vimentin were novel autoantibodies in the ascites of relapsed PTX-resistant GC patients. These autoantibodies may be used as potential biomarkers to monitor the occurrence of PTX-resistance.

scholarly journals Oxonium Ion Guided Analysis of Quantitative Proteomics Data Reveals Site-Specific O-Glycosylation of Anterior Gradient Protein 2 (AGR2)

2021 ◽  
Vol 22 (10) ◽  
pp. 5369
Author(s):  
Martina Pirro ◽  
Yassene Mohammed ◽  
Arnoud H. de Ru ◽  
George M. C. Janssen ◽  
Rayman T. N. Tjokrodirijo ◽  
...  
Keyword(s):  
Cell Lines ◽  
Quantitative Proteomics ◽  
Glycosylation Site ◽  
Total Cell ◽  
Tandem Mass ◽  
Proteomics Data ◽  
Site Specific ◽  
Oxonium Ions ◽  
Tandem Mass Tag ◽  
Colorectal Cancer Cell Lines

Developments in mass spectrometry (MS)-based analyses of glycoproteins have been important to study changes in glycosylation related to disease. Recently, the characteristic pattern of oxonium ions in glycopeptide fragmentation spectra had been used to assign different sets of glycopeptides. In particular, this was helpful to discriminate between O-GalNAc and O-GlcNAc. Here, we thought to investigate how such information can be used to examine quantitative proteomics data. For this purpose, we used tandem mass tag (TMT)-labeled samples from total cell lysates and secreted proteins from three different colorectal cancer cell lines. Following automated glycopeptide assignment (Byonic) and evaluation of the presence and relative intensity of oxonium ions, we observed that, in particular, the ratio of the ions at m/z 144.066 and 138.055, respectively, could be used to discriminate between O-GlcNAcylated and O-GalNAcylated peptides, with concomitant relative quantification between the different cell lines. Among the O-GalNAcylated proteins, we also observed anterior gradient protein 2 (AGR2), a protein which glycosylation site and status was hitherto not well documented. Using a combination of multiple fragmentation methods, we then not only assigned the site of modification, but also showed different glycosylation between intracellular (ER-resident) and secreted AGR2. Overall, our study shows the potential of broad application of the use of the relative intensities of oxonium ions for the confident assignment of glycopeptides, even in complex proteomics datasets.

scholarly journals Quantitative Top-Down Proteomics in Complex Samples Using Protein-Level Tandem Mass Tag Labeling

2021 ◽  
Author(s):  
Dahang Yu ◽  
Zhe Wang ◽  
Kellye A. Cupp-Sutton ◽  
Yanting Guo ◽  
Qiang Kou ◽  
...  
Keyword(s):  
Protein Level ◽  
Tandem Mass ◽  
Top Down ◽  
Complex Samples ◽  
Tandem Mass Tag ◽  
Mass Tag

scholarly journals Tandem Mass Tag-Based Quantitative Proteomics and Virulence Phenotype of Hemolymph-Treated Bacillus thuringiensis kurstaki Cells Reveal New Insights on Bacterial Pathogenesis in Insects

2021 ◽  
Author(s):  
Yanyan Sun ◽  
Linlin Yang ◽  
Lianet Rodríguez-Cabrera ◽  
Yushan Ding ◽  
Chaoliang Leng ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Quantitative Proteomics ◽  
Bacterial Pathogenesis ◽  
Midgut Epithelium ◽  
Tandem Mass ◽  
Content Type ◽  
Virulence Phenotype ◽  
Bacillus Thuringiensis Kurstaki ◽  
Tandem Mass Tag ◽  
Mass Tag

After ingestion by a susceptible insect and damaging its midgut epithelium, the bacterium Bacillus thuringiensis (Bt) reaches the insect blood (hemolymph), where it propagates despite the host’s antimicrobial defenses and induces insect death by acute septicemia. Although the hemolymph stage of the Bt toxic pathway is determinant for the infested insects’ fate, the response of Bt to hemolymph and the latter’s role in bacterial pathogenesis has been poorly explored.

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