A proteomic perspective on TNF-mediated signalling and cell death

The tumour necrosis factor (TNF) is the most potent inducer of cell death amongst cyto-kines. It is crucial for processes including homeostasis, the development of the immune system and fighting infections. However, high levels of TNF due to genetic disorders or persistent infections can contribute to autoinflammatory and autoimmune diseases or life-threatening conditions like sepsis. These diseases generally display increased levels of cell death, which, downstream of the TNF receptor, can either be caspase-dependent (apoptosis) or caspase-independent (necroptosis). Significant efforts have been invested in unravelling and manipulating signalling mechanisms regulating these two different types of cell death. Here I discuss how modern proteomic approaches like phosphopro-teomics and secretomics provide a novel perspective on this central cytokine and its effect on inflammation and cell survival

The Highway Patrol Officer as Expert Witness

Expert Witnes

Perturbation solutions of fifth order oscillatory nonlinear systems

Oscillatory systems play an important role in the nature. Many engineering problems and physical systems of fifth degrees of freedom are oscillatory and their governing equations are fifth order nonlinear differential equations. To investigate the solution of fifth order weakly nonlinear oscillatory systems, in this article the Krylov–Bogoliubov–Mitropolskii (KBM) method has been extended and desired solution is found. An example is solved to illustrate the method. The results obtain by the extended KBM method show good agreement with those obtained by numerical method

Cortical thickness of the insula and prefrontal cortex relates to externalizing behavior: Cross-sectional and prospective findings

Externalizing behaviors (EBs) pertain to a diverse set of aggressive, antisocial, and potentially destructive behaviors directed toward the external environment. They range from nonclinical to clinical in severity, associated with opposition, aggression, hyperactivity, or impulsivity, and are considered a risk factor for the emergence of psychopathology later in adulthood. Focusing on community adolescents (N = 102; 49 female and 53 male adolescents; age range 12-19 years), this study aimed to explore the relations between EBs and the cortical thickness of regions of interest as well as to identify possible risk markers that could improve understanding of the EB construct. Using a mixed cross-sectional and prospective design (1-year follow-up), we report specific associations with cortical thickness of the left insular, right orbitofrontal, and left anterior cingulate cortex. Specifically, thinner left insular and right orbitofrontal cortex was associated with higher EBs, and thinner left anterior cingulate cortex predicted less reduction in EBs 1 year later. In addition, further examination of the aggression and rule-breaking subscales of the Youth/Adult Self-Report, used to assess EBs, revealed specific associations with insular subregions. Findings suggest that cortical structure morphology may significantly relate to the expression and maintenance of EBs within the general population of adolescents

Phosphoproteome profiling uncovers a key role for CDKs in TNF signaling

Tumor necrosis factor (TNF) has various effects on phosphorylation-mediated cellular signaling. Combining phosphoproteomics, subcellular localization analyses and kinase inhibitor assays, the authors provide systems level insights into TNF signaling and identify modulators of TNF-induced cell death. Tumor necrosis factor (TNF) is one of the few cytokines successfully targeted by therapies against inflammatory diseases. However, blocking this well studied and pleiotropic ligand can cause dramatic side-effects. Here, we reason that a systems-level proteomic analysis of TNF signaling could dissect its diverse functions and offer a base for developing more targeted therapies. Therefore, we combine phosphoproteomics time course experiments with subcellular localization and kinase inhibitor analysis to identify functional modules of protein phosphorylation. The majority of regulated phosphorylation events can be assigned to an upstream kinase by inhibiting master kinases. Spatial proteomics reveals phosphorylation-dependent translocations of hundreds of proteins upon TNF stimulation. Phosphoproteome analysis of TNF-induced apoptosis and necroptosis uncovers a key role for transcriptional cyclin-dependent kinase activity to promote cytokine production and prevent excessive cell death downstream of the TNF signaling receptor. This resource of TNF-induced pathways and sites can be explored at

Quantitative and Dynamic Catalogs of Proteins Released during Apoptotic and Necroptotic Cell Death

The inflammatory functions of the cytokine tumor necrosis factor (TNF) rely on its ability to induce cytokine production and to induce cell death. Caspase-dependent and caspase-independent pathways-apoptosis and necroptosis, respectively-regulate immunogenicity by the release of distinct sets of cellular proteins. To obtain an unbiased, systems-level understanding of this important process, we here applied mass spectrometry-based proteomics to dissect protein release during apoptosis and necroptosis. We report hundreds of proteins released from human myeloid cells in time course experiments. Both cell death types induce receptor shedding, but only apoptotic cells released nucleosome components. Conversely, necroptotic cells release lysosomal components by activating lysosomal exocytosis at early stages of necroptosis-induced membrane permeabilization and show reduced release of conventionally secreted cytokines

Interaction of Salivary alpha-Amylase and Amylase-Binding-Protein A (AbpA) of Streptococcus gordonii with Glucosyltransferase of S. gordonii and Streptococcus mutans

<p>Abstract</p> <p>Background</p> <p>Glucosyltransferases (Gtfs), enzymes that produce extracellular glucans from dietary sucrose, contribute to dental plaque formation by <it>Streptococcus gordonii </it>and <it>Streptococcus mutans</it>. The alpha-amylase-binding protein A (AbpA) of <it>S. gordonii</it>, an early colonizing bacterium in dental plaque, interacts with salivary amylase and may influence dental plaque formation by this organism. We examined the interaction of amylase and recombinant AbpA (rAbpA), together with Gtfs of <it>S. gordonii </it>and <it>S. mutans</it>.</p> <p>Results</p> <p>The addition of salivary alpha-amylase to culture supernatants of <it>S. gordonii </it>precipitated a protein complex containing amylase, AbpA, amylase-binding protein B (AbpB), and the glucosyltransferase produced by <it>S. gordonii </it>(Gtf-G). rAbpA was expressed from an inducible plasmid, purified from <it>Escherichia coli </it>and characterized. Purified rAbpA, along with purified amylase, interacted with and precipitated Gtfs from culture supernatants of both <it>S. gordonii </it>and <it>S. mutans</it>. The presence of amylase and/or rAbpA increased both the sucrase and transferase component activities of <it>S. mutans </it>Gtf-B. Enzyme-linked immunosorbent assay (ELISA) using anti-Gtf-B antibody verified the interaction of rAbpA and amylase with Gtf-B. A <it>S. gordonii abp</it>A-deficient mutant showed greater biofilm growth under static conditions than wild-type in the presence of sucrose. Interestingly, biofilm formation by every strain was inhibited in the presence of saliva.</p> <p>Conclusion</p> <p>The results suggest that an extracellular protein network of AbpA-amylase-Gtf may influence the ecology of oral biofilms, likely during initial phases of colonization.</p