@article {513, title = {L-Plastin S-glutathionylation promotes reduced binding to β-actin and affects neutrophil functions. (Mass Spectrometry)}, journal = {Free Radic Biol Med}, volume = {86}, year = {2015}, month = {2015 Sep}, pages = {1-15}, abstract = {

Posttranslational modifications (PTMs) of cytoskeleton proteins due to oxidative stress associated with several pathological conditions often lead to alterations in cell function. The current study evaluates the effect of nitric oxide (DETA-NO)-induced oxidative stress-related S-glutathionylation of cytoskeleton proteins in human PMNs. By using in vitro and genetic approaches, we showed that S-glutathionylation of L-plastin (LPL) and β-actin promotes reduced chemotaxis, polarization, bactericidal activity, and phagocytosis. We identified Cys-206, Cys-283, and Cys-460as S-thiolated residues in the β-actin-binding domain of LPL, where cys-460 had the maximum score. Site-directed mutagenesis of LPL Cys-460 further confirmed the role in the redox regulation of LPL. S-Thiolation diminished binding as well as the bundling activity of LPL. The presence of S-thiolated LPL was detected in neutrophils from both diabetic patients and db/db mice with impaired PMN functions. Thus, enhanced nitroxidative stress may results in LPL S-glutathionylation leading to impaired chemotaxis, polarization, and bactericidal activity of human PMNs, providing a mechanistic basis for their impaired functions in diabetes mellitus.

}, keywords = {Actins, Adult, Amino Acid Sequence, Animals, Case-Control Studies, Cell Polarity, Chemotaxis, Diabetes Mellitus, Female, Glutathione, HEK293 Cells, Humans, Male, Mice, Inbred C57BL, Mice, Obese, Microfilament Proteins, Middle Aged, Molecular Sequence Data, Neutrophils, Nitric Oxide, Oxidative Stress, Protein Binding, Protein Processing, Post-Translational, Young Adult}, issn = {1873-4596}, doi = {10.1016/j.freeradbiomed.2015.04.008}, author = {Dubey, Megha and Singh, Abhishek K and Awasthi, Deepika and Nagarkoti, Sheela and Kumar, Sachin and Ali, Wahid and Chandra, Tulika and Kumar, Vikas and Barthwal, Manoj K and Jagavelu, Kumaravelu and S{\'a}nchez-G{\'o}mez, Francisco J and Lamas, Santiago and Dikshit, Madhu} } @article {477, title = {A genetic RNAi screen for IP$_{3}$/Ca{\texttwosuperior}$^{+}$ coupled GPCRs in Drosophila identifies the PdfR as a regulator of insect flight. [Drosophila facility]}, journal = {PLoS Genet}, volume = {9}, year = {2013}, month = {2013}, pages = {e1003849}, abstract = {

Insect flight is regulated by various sensory inputs and neuromodulatory circuits which function in synchrony to control and fine-tune the final behavioral outcome. The cellular and molecular bases of flight neuromodulatory circuits are not well defined. In Drosophila melanogaster, it is known that neuronal IP3 receptor mediated Ca{\texttwosuperior}$^{+}$ signaling and store-operated Ca{\texttwosuperior}$^{+}$ entry (SOCE) are required for air-puff stimulated adult flight. However, G-protein coupled receptors (GPCRs) that activate intracellular Ca{\texttwosuperior}$^{+}$ signaling in the context of flight are unknown in Drosophila. We performed a genetic RNAi screen to identify GPCRs that regulate flight by activating the IPIP$_{3}$ receptor. Among the 108 GPCRs screened, we discovered 5 IPIP$_{3}$/Ca{\texttwosuperior}$^{+}$ linked GPCRs that are necessary for maintenance of air-puff stimulated flight. Analysis of their temporal requirement established that while some GPCRs are required only during flight circuit development, others are required both in pupal development as well as during adult flight. Interestingly, our study identified the Pigment Dispersing Factor Receptor (PdfR) as a regulator of flight circuit development and as a modulator of acute flight. From the analysis of PdfR expressing neurons relevant for flight and its well-defined roles in other behavioral paradigms, we propose that PdfR signaling functions systemically to integrate multiple sensory inputs and modulate downstream motor behavior.

}, keywords = {Adult, Animals, Calcium Signaling, Drosophila melanogaster, Drosophila Proteins, Flight, Animal, Humans, Inositol 1,4,5-Trisphosphate Receptors, Neurons, Receptors, G-Protein-Coupled, RNA Interference, Signal Transduction}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1003849}, author = {Agrawal, Tarjani and Sadaf, Sufia and Hasan, Gaiti} } @article {724, title = {Neutrophil extracellular traps contain mitochondrial as well as nuclear DNA and exhibit inflammatory potential.}, journal = {Cytometry A}, volume = {81}, year = {2012}, month = {2012 Mar}, pages = {238-47}, abstract = {

Neutrophils expel extracellular traps (NETs) to entrap and exterminate the invaded micro-organisms. Acute/chronic inflammatory disorders are often observed with aberrantly enhanced NETs formation and high nitric oxide (NO) availability. Recent study from this laboratory demonstrated release of NETs from human neutrophils following treatment with SNP or SNAP. This study is an extension of our previous finding to explore the extracellular bacterial killing, source of DNA in the expelled NETs, their ability to induce proinflammatory cytokines release from platelets/THP-1 cells, and assessment of NO-mediated free radical formation by using a consistent NO donor, DETA-NONOate. NO-mediated NETs exhibited extracellular bacterial killing as determined by colony forming units. NO-mediated NETs formation was due to the activation of NADPH oxidase and myeloperoxidase. NO- or PMA-mediated NETs were positive for both nuclear and mitochondrial DNA as well as proteolytic enzymes. Incubation of NETs with human platelets enhanced the release of IL-1β and IL-8, while with THP-1 cells, release of IL-1β, IL-8, and TNFα was observed. This study demonstrates that NO by augmenting enzymatic free radical generation release NETs to promote extracellular bacterial killing. These NETs were made up of mitochondrial and nuclear DNA and potentiated release of proinflammatory cytokines.

}, keywords = {Adult, Blood Platelets, DNA, DNA, Mitochondrial, Free Radicals, Humans, Inflammation, Interleukin-1beta, Interleukin-8, Mitochondria, NADPH Oxidases, Neutrophil Activation, Neutrophils, Nitric Oxide, Peroxidase, Tumor Necrosis Factor-alpha}, issn = {1552-4930}, doi = {10.1002/cyto.a.21178}, author = {Keshari, Ravi S and Jyoti, Anupam and Kumar, Sachin and Dubey, Megha and Verma, Anupam and Srinag, Bangalore S and Krishnamurthy, Hanumanthappa and Barthwal, Manoj K and Dikshit, Madhu} }