@article {8740, title = {Neem leaf glycoprotein binding to Dectin-1 receptors on dendritic cell induces type-1 immunity through CARD9 mediated intracellular signal to NFκB. [Mass Spectrometry - Proteomics Facility]}, journal = {Cell Commun Signal}, volume = {22}, year = {2024}, month = {2024 Apr 23}, pages = {237}, abstract = {

BACKGROUND: A water-soluble ingredient of mature leaves of the tropical mahogany {\textquoteright}Neem{\textquoteright} (Azadirachta indica), was identified as glycoprotein, thus being named as {\textquoteright}Neem Leaf Glycoprotein{\textquoteright} (NLGP). This non-toxic leaf-component regressed cancerous murine tumors (melanoma, carcinoma, sarcoma) recurrently in different experimental circumstances by boosting prime antitumor immune attributes. Such antitumor immunomodulation, aid cytotoxic T cell (T)-based annihilation of tumor cells. This study focused on identifying and characterizing the signaling gateway that initiate this systemic immunomodulation. In search of this gateway, antigen-presenting cells (APCs) were explored, which activate and induce the cytotoxic thrust in T cells.

METHODS: Six glycoprotein-binding C-type lectins found on APCs, namely, MBR, Dectin-1, Dectin-2, DC-SIGN, DEC205 and DNGR-1 were screened on bone marrow-derived dendritic cells from C57BL/6\ J mice. Fluorescence microscopy, RT-PCR, flow cytometry and ELISA revealed Dectin-1 as the NLGP-binding receptor, followed by verifications through RNAi. Following detection of β-Glucans in NLGP, their interactions with Dectin-1 were explored in silico. Roles of second messengers and transcription factors in the downstream signal were studied by co-immunoprecipitation, western blotting, and chromatin-immunoprecipitation. Intracellularization of FITC-coupled NLGP was observed by processing confocal micrographs of DCs.

RESULTS: Considering extents of hindrance in NLGP-driven transcription rates of the cytokines IL-10 and IL-12p35 by receptor-neutralization, Dectin-1 receptors on dendritic cells were found to bind NLGP through the ligand{\textquoteright}s peripheral β-Glucan chains. The resulting signal phosphorylates PKCδ, forming a trimolecular complex of CARD9, Bcl10 and MALT1, which in turn activates the canonical NFκB-pathway of transcription-regulation. Consequently, the NFκB-heterodimer p65:p50 enhances Il12a transcription and the p50:p50 homodimer represses Il10 transcription, bringing about a cytokine-based systemic-bias towards type-1 immune environment. Further, NLGP gets engulfed within dendritic cells, possibly through endocytic activities of Dectin-1.

CONCLUSION: NLGP{\textquoteright}s binding to Dectin-1 receptors on murine dendritic cells, followed by the intracellular signal, lead to NFκB-mediated contrasting regulation of cytokine-transcriptions, initiating a pro-inflammatory immunopolarization, which amplifies further by the responding immune cells including T cells, alongside their enhanced cytotoxicity. These insights into the initiation of mammalian systemic immunomodulation by NLGP at cellular and molecular levels, may help uncovering its mode of action as a novel immunomodulator against human cancers, following clinical trials.

}, keywords = {Animals, Azadirachta, CARD Signaling Adaptor Proteins, Dendritic Cells, Lectins, C-Type, Mice, Mice, Inbred C57BL, NF-kappa B, Plant Leaves, Protein Binding, Signal Transduction}, issn = {1478-811X}, doi = {10.1186/s12964-024-01576-z}, author = {Ganguly, Nilanjan and Das, Tapasi and Bhuniya, Avishek and Guha, Ipsita and Chakravarti, Mohona and Dhar, Sukanya and Sarkar, Anirban and Bera, Saurav and Dhar, Jesmita and Dasgupta, Shayani and Saha, Akata and Ghosh, Tithi and Das, Juhina and Sk, Ugir Hossain and Banerjee, Saptak and Laskar, Subrata and Bose, Anamika and Baral, Rathindranath} } @article {1015, title = {Mechanochemical feedback control of dynamin independent endocytosis modulates membrane tension in adherent cells. [Microfluidics and Microfabrication Facility (INT)]}, journal = {Nat Commun}, volume = {9}, year = {2018}, month = {2018 10 11}, pages = {4217}, abstract = {

Plasma membrane tension regulates many key cellular processes. It is modulated by, and can modulate, membrane trafficking. However, the cellular pathway(s) involved in this interplay is poorly understood. Here we find that, among a number of endocytic processes operating simultaneously at the cell surface, a dynamin independent pathway, the CLIC/GEEC (CG) pathway, is rapidly and specifically upregulated upon a sudden reduction of tension. Moreover, inhibition (activation) of the CG pathway results in lower (higher) membrane tension. However, alteration in membrane tension does not directly modulate CG endocytosis. This requires vinculin, a mechano-transducer recruited to focal adhesion in adherent cells. Vinculin acts by controlling the levels of a key regulator of the CG pathway, GBF1, at the plasma membrane. Thus, the CG pathway directly regulates membrane tension and is in turn controlled via a mechano-chemical feedback inhibition, potentially leading to homeostatic regulation of membrane tension in adherent cells.

}, keywords = {Animals, Biomechanical Phenomena, Cell Adhesion, Cell Membrane, Dynamins, Endocytosis, Feedback, Physiological, Mechanotransduction, Cellular, Mice, Signal Transduction, Temperature, Vinculin}, issn = {2041-1723}, doi = {10.1038/s41467-018-06738-5}, author = {Thottacherry, Joseph Jose and Kosmalska, Anita Joanna and Kumar, Amit and Vishen, Amit Singh and Elosegui-Artola, Alberto and Pradhan, Susav and Sharma, Sumit and Singh, Parvinder P and Guadamillas, Marta C and Chaudhary, Natasha and Vishwakarma, Ram and Trepat, Xavier and Del Pozo, Miguel A and Parton, Robert G and Rao, Madan and Pullarkat, Pramod and Roca-Cusachs, Pere and Mayor, Satyajit} } @article {706, title = {Dynein Clusters into Lipid Microdomains on Phagosomes to Drive Rapid Transport toward Lysosomes.}, journal = {Cell}, volume = {164}, year = {2016}, month = {2016 Feb 11}, pages = {722-34}, abstract = {

Diverse cellular processes are driven by motor proteins that are recruited to and generate force on lipid membranes. Surprisingly little is known about how membranes control the force from motors and how this may impact specific cellular functions. Here, we show that dynein motors physically cluster into microdomains on the membrane of a phagosome as it matures inside cells. Such geometrical reorganization allows many dyneins within a cluster to generate cooperative force on a single microtubule. This results in rapid directed transport of the phagosome toward microtubule minus ends, likely promoting phagolysosome fusion and pathogen degradation. We show that lipophosphoglycan, the major molecule implicated in immune evasion of Leishmania donovani, inhibits phagosome motion by disrupting the clustering and therefore the cooperative force generation of dynein. These findings appear relevant to several pathogens that prevent phagosome-lysosome fusion by targeting lipid microdomains on phagosomes.

}, keywords = {Animals, Biological Transport, Cell Line, Dictyostelium, Dyneins, Glycosphingolipids, Leishmania donovani, Lysosomes, Membrane Microdomains, Mice, Phagosomes}, issn = {1097-4172}, doi = {10.1016/j.cell.2015.12.054}, author = {Rai, Ashim and Pathak, Divya and Thakur, Shreyasi and Singh, Shampa and Dubey, Alok Kumar and Mallik, Roop} } @article {515, title = {Biochemical and pharmacological characterization of a toxic fraction and its cytotoxin-like component isolated from Russell{\textquoteright}s viper (Daboia russelii russelii) venom. (Mass Spectrometry)}, journal = {Comp Biochem Physiol C Toxicol Pharmacol}, volume = {168}, year = {2015}, month = {2015 Feb}, pages = {55-65}, abstract = {

The pathophysiological significance of a toxic fraction (GF-VI DEAE-II) isolated from Russell{\textquoteright}s viper venom (RVV) is characterized. GF-VI DEAE-II represents 1.6\% of the total RVV protein and it comprises of a 27.6kDa minor component (RP-I) (0.04\%, w/w) and a major 6.6kDa non-enzymatic peptide (1.11\%, w/w), named Rusvitoxin. The LC-MS/MS analysis of RP-I showed its identity to snake venom serine proteases, whereas Rusvitoxin demonstrated its close identity with snake venom three finger toxins, cytotoxins and cardiotoxins particularly from Naja sp. GF-VI DEAE-II was found to be non-cytotoxic to the tested mammalian cancer cells and non-hemolytic; nevertheless, it demonstrated α-fibrin(ogen)ase activity and in vivo toxicity in BALB/c mice with an LD50 (i.p.) of 2.3mg/kg. GF-VI DEAE-II induced lethargy and hind-leg paralysis in mice within 10min of i.p. injection. GF-VI DEAE-II induced hyperfibrinogenomia, and significantly altered (p\<0.05) the plasma levels of factor X, pro- and anti-inflammatory cytokines viz. TNF-α, IL-6 and IL-10 in treated mice. Histological observations of tissues and biochemical properties of serum from GF-VI DEAE-II-treated mice suggested multiple organ dysfunctions. Conversely, Rusvitoxin at a dose of 5mg/kg did not induce toxicity in BALB/c mice. At 1:15 (antigen: antivenom, w/w) ratio, commercially polyvalent and monovalent antivenoms neutralized more than 80\% of the fibrinolytic and anticoagulant activities of GF-VI DEAE-II. The present study suggests the significant role of GF-VI DEAE-II in RVV-induced pathogenesis in victim/prey.

}, keywords = {Animals, Anticoagulants, Antivenins, Cytotoxins, Fibrinolytic Agents, Interleukin-10, Interleukin-6, Mice, Mice, Inbred BALB C, Mollusk Venoms, Russell{\textquoteright}s Viper, Tumor Necrosis Factor-alpha, Viper Venoms}, issn = {1532-0456}, doi = {10.1016/j.cbpc.2014.12.001}, author = {Thakur, Rupamoni and Chattopadhyay, Pronobesh and Mukherjee, Ashis K} } @article {497, title = {Protective effect of Euphorbia hirta and its components against snake venom induced lethality. [Mass spectrometry - Metabolomics]}, journal = {J Ethnopharmacol}, volume = {165}, year = {2015}, month = {2015 May 13}, pages = {180-90}, abstract = {

ETHNOPHARMACOLOGICAL RELEVANCE: Despite the use of snake anti-venom therapy, herbal medicine is still in practice to treat snakebites. Euphorbia hirta is traditionally used as antidote for snakebites and also for numerous other ailments. However, the scientific evidence for its anti-snake venom property is still lacking.

MATERIALS AND METHODS: Methanolic extract of E. hirta was evaluated for anti-venom activity under in vitro and ex vivo conditions. Histopathological changes in the vital organs of the mice were also monitored. UHPLC-SRM/MS was used to estimate the phenolic constituents whereas GC-MS analysis was performed to analyze the volatile metabolites present. The major compound was further evaluated for its contribution to the overall inhibitory potential of the extract.

RESULTS: Methanolic extract of E. hirta completely inhibited the venom enzymes under in vitro and reduced the edema ratio. The extract increased the survival time (\>24h) of mice which was further evidenced by histopathological analysis of vital organs. Phytochemical analysis revealed higher content of phenolic (144 mg/g extract) compounds in the extract. UHPLC-SRM/MS demonstrated that ellagic acid, gallic acid and quinic acid are the major phenolics whereas GC-MS analysis revealed pyrogallol as the major constituent (60.07\%) among the volatile components of the extract. It was also shown that pyrogallol has the ability to differentially inhibit venom protease but not phospholipase A2.

CONCLUSION: The present study confirmed that E. hirta methanolic extract was able to completely inhibit Naja naja venom induced toxicity under in vitro as well as ex vivo conditions, thus providing scientific evidence to its traditional use.

}, keywords = {Animals, Chromatography, High Pressure Liquid, Cobra Venoms, Euphorbia, Male, Mass Spectrometry, Mice, Phytotherapy, Plant Extracts, Snake Bites, Snake Venoms}, issn = {1872-7573}, doi = {10.1016/j.jep.2015.02.044}, author = {Gopi, Kadiyala and Renu, Kadali and Sannanaik Vishwanath, Bannikuppe and Jayaraman, Gurunathan} } @article {536, title = {Does reversible cysteine oxidation link the Western diet to cardiac dysfunction?}, journal = {FASEB J}, volume = {28}, year = {2014}, month = {2014 May}, pages = {1975-87}, abstract = {

Using a novel cysteine thiol labeling strategy coupled with mass spectrometric analysis, we identified and quantified the changes in global reversible cysteine oxidation of proteins in the left ventricle of hearts from mice with metabolic syndrome-associated diastolic dysfunction. This phenotype was induced by feeding a high-fat, high-sucrose, type-2 diabetogenic diet to C57BL/6J mice for 8 mo. The extent of reversible thiol oxidation in relationship to the total available (free and reducible) level of each cysteine could be confidently determined for 173 proteins, of which 98 contained cysteines differentially modified >=1.5-fold by the diet. Our findings suggest that the metabolic syndrome leads to potentially deleterious changes in the oxidative modification of metabolically active proteins. These alterations may adversely regulate energy substrate flux through glycolysis, β-oxidation, citric acid (TCA) cycle, and oxidative phosphorylation (oxphos), thereby contributing to maladaptive tissue remodeling that is associated with, and possibly contributing to, diastolic left ventricular dysfunction.

}, keywords = {Animals, Chromatography, Liquid, Citric Acid Cycle, Cysteine, Diet, Fatty Acids, Glycolysis, Heart Diseases, Male, Mice, Mice, Inbred C57BL, Myocardial Contraction, Myocardium, Obesity, Oxidative Phosphorylation, Oxygen, Phenotype, Protein Processing, Post-Translational, Proteomics, Reactive Nitrogen Species, Reactive Oxygen Species, Sulfhydryl Compounds, Tandem Mass Spectrometry}, issn = {1530-6860}, doi = {10.1096/fj.13-233445}, author = {Behring, Jessica B and Kumar, Vikas and Whelan, Stephen A and Chauhan, Pratibha and Siwik, Deborah A and Costello, Catherine E and Colucci, Wilson S and Cohen, Richard A and McComb, Mark E and Bachschmid, Markus M} } @article {516, title = {A new C-type lectin (RVsnaclec) purified from venom of Daboia russelii russelii shows anticoagulant activity via inhibition of FXa and concentration-dependent differential response to platelets in a Ca{\texttwosuperior}$^{+}$-independent manner. (Mass spectrometry)}, journal = {Thromb Res}, volume = {134}, year = {2014}, month = {2014 Nov}, pages = {1150-6}, abstract = {

This is the first report on the characterization of a snaclec (RVsnaclec) purified from Daboia russelii russelii venom. The RVsnaclec is a heterodimer of two subunits, α (15.1 kDa) and β (9 kDa). These subunits are covalently linked to form multimeric (αβ)$_{2}$ and (αβ)$_{4}$ structures. Peptide mass fingerprinting analysis of RVsnaclec via LC-MS/MS demonstrated its similarity to snaclecs purified from other viperid snake venoms. Two tryptic peptide sequences of RVsnaclec revealed the putative conserved domains of C-type lectin (CTL). RVsnaclec dose-dependently increased the Ca-clotting time and prothrombin time of platelet-poor plasma (PPP); however, it did not affect the partial thromboplastin time (APTT) or thrombin time of PPP. The in vitro and in vivo anticoagulant activity of RVsnaclec is correlated to its binding and subsequent uncompetitive inhibition of FXa (Ki = 0.52 μmole) in a Ca(2+)-independent manner; however, supplementation with 0.25 mM Ca(2+) enhanced the Xa binding potency of RVsnaclec. Monovalent or polyvalent antivenom failed to neutralize its anticoagulant potency, and RVsnaclec did not inhibit trypsin, chymotrypsin, thrombin or plasmin. RVsnaclec was devoid of hemolytic activity or cytotoxicity against several human cancer cell lines, demonstrated concentration-dependent aggregation and deaggregation of human platelets, and inhibited the ADP-induced aggregation of platelet. RVsnaclec (5.0 mg/kg body weight) was non-lethal to mice and showed no adverse pharmacological effects, suggesting that it has potential as a lead compound for future therapeutic applications in cardiovascular disorders.

}, keywords = {Animals, Anticoagulants, Blood Coagulation, Blood Platelets, Calcium, Factor Xa, Factor Xa Inhibitors, Goats, Humans, Lectins, C-Type, Mice, Platelet Aggregation, Russell{\textquoteright}s Viper, Viper Venoms}, issn = {1879-2472}, doi = {10.1016/j.thromres.2014.09.009}, author = {Mukherjee, Ashis K and Dutta, Sumita and Mackessy, Stephen P} } @article {537, title = {Redox proteomics of thiol proteins in mouse heart during ischemia/reperfusion using ICAT reagents and mass spectrometry.}, journal = {Free Radic Biol Med}, volume = {58}, year = {2013}, month = {2013 May}, pages = {109-17}, abstract = {

There is strong evidence for the involvement of reactive oxygen species in ischemia/reperfusion injury. Although oxidation of individual thiol proteins has been reported, more extensive redox proteomics of hearts subjected to ischemia/reperfusion has not been performed. We have carried out an exploratory study using mass spectrometry with isotope-coded affinity tags (ICAT) aimed at identifying reversible oxidative changes to protein thiols in Langendorff perfused isolated mouse hearts subjected to 20 min ischemia with or without aerobic reperfusion for 5 or 30 min. Reduced thiols were blocked by adding N-ethylmaleimide during protein extraction, then reversibly oxidized thiols in extracts of control perfused and treated hearts were reduced and labeled with the light and heavy ICAT reagents, respectively. Protein extracts were mixed in equal amounts and relative proportions of the isotope-labeled peaks were used to quantify oxidative changes between the control and the treated groups. Approximately 300 peptides with ICAT signatures were reliably identified in each sample, with 181 peptides from 118 proteins common to all treatments. A proportion showed elevated ICAT ratios, consistent with reversible thiol oxidation. This was most evident after early reperfusion, with apparent reversal after longer reperfusion. In comparison, there was gradual accumulation of protein carbonyls and loss of GSH with longer reperfusion. Many of the thiol changes were in mitochondrial proteins, including components of electron transport complexes and enzymes involved in lipid metabolism. The results are consistent with mitochondria being a major site of oxidant generation during early cardiac reperfusion and mitochondrial thiol proteins being targets for oxidation.

}, keywords = {Animals, Isotope Labeling, Mass Spectrometry, Mice, Mitochondrial Proteins, Myocardium, Oxidation-Reduction, Proteomics, Reactive Oxygen Species, Reperfusion Injury, Sulfhydryl Compounds}, issn = {1873-4596}, doi = {10.1016/j.freeradbiomed.2013.01.021}, author = {Kumar, Vikas and Kleffmann, Torsten and Hampton, Mark B and Cannell, Mark B and Winterbourn, Christine C} } @article {519, title = {Unexpected histone H3 tail-clipping activity of glutamate dehydrogenase. (Mass spectrometry - Proteomics)}, journal = {J Biol Chem}, volume = {288}, year = {2013}, month = {2013 Jun 28}, pages = {18743-57}, abstract = {

Clipping of histone tails has been reported in several organisms. However, the significance and regulation of histone tail clipping largely remains unclear. According to recent discoveries H3 clipping has been found to be involved in regulation of gene expression and chromatin dynamics. Earlier we had provided evidence of tissue-specific proteolytic processing of histone H3 in White Leghorn chicken liver nuclei. In this study we identify a novel activity of glutamate dehydrogenase (GDH) as a histone H3-specific protease in chicken liver tissue. This protease activity is regulated by divalent ions and thiol-disulfide conversion in vitro. GDH specifically clips H3 in its free as well as chromatin-bound form. Furthermore, we have found an inhibitor that inhibits the H3-clipping activity of GDH. Like previously reported proteases, GDH too may have the potential to regulate/modulate post-translational modifications of histone H3 by removing the N-terminal residues of the histone. In short, our findings identify an unexpected proteolytic activity of GDH specific to histone H3 that is regulated by redox state, ionic concentrations, and a cellular inhibitor in vitro.

}, keywords = {Amino Acid Sequence, Animals, Binding Sites, Brain, Chickens, Chromatin, Cysteine Proteases, Disulfides, Epigenesis, Genetic, Gene Expression Regulation, Enzymologic, Glutamate Dehydrogenase, Histones, Hydrogen-Ion Concentration, Liver, Mass Spectrometry, Mice, Molecular Sequence Data, Rats, Recombinant Proteins, Salts, Sulfhydryl Compounds, Temperature}, issn = {1083-351X}, doi = {10.1074/jbc.M113.462531}, author = {Mandal, Papita and Verma, Naveen and Chauhan, Sakshi and Tomar, Raghuvir S} } @article {718, title = {Development of the structural core and of conformational heterogeneity during the conversion of oligomers of the mouse prion protein to worm-like amyloid fibrils.}, journal = {J Mol Biol}, volume = {423}, year = {2012}, month = {2012 Oct 19}, pages = {217-31}, abstract = {

Understanding how structure develops during the course of amyloid fibril formation by the prion protein is important for understanding prion diseases. Determining how conformational heterogeneity manifests itself in the fibrillar and pre-fibrillar amyloid aggregates is critical for understanding prion strain phenotypes. In this study, the formation of worm-like amyloid fibrils by the mouse prion protein has been characterized structurally by hydrogen-deuterium exchange coupled to mass spectrometry. The structural cores of these fibrils and of the oligomer on the direct pathway of amyloid fibril formation have been defined, showing how structure develops during fibril formation. The structural core of the oligomer not on the direct pathway has also been defined, allowing the delineation of the structural features that make this off-pathway oligomer incompetent to directly form fibrils. Sequence segments that exhibit multiple local conformations in the three amyloid aggregates have been identified, and the development of structural heterogeneity during fibril formation has been characterized. It is shown that conformational heterogeneity is not restricted to only the C-terminal domain region, which forms the structural core of the aggregates; it manifests itself in the N-terminal domain of the protein as well. Importantly, all three amyloid aggregates are shown to be capable of disrupting lipid membrane structure, pointing to a mechanism by which they may be toxic.

}, keywords = {Amino Acid Sequence, Amyloid, Animals, Deuterium Exchange Measurement, Kinetics, Mice, Models, Molecular, Molecular Sequence Data, Prion Proteins, Prions, Protein Conformation, Protein Folding}, issn = {1089-8638}, doi = {10.1016/j.jmb.2012.06.040}, author = {Singh, Jogender and Sabareesan, A T and Mathew, M K and Udgaonkar, Jayant B} } @article {717, title = {Developmental heterogeneity in DNA packaging patterns influences T-cell activation and transmigration.}, journal = {PLoS One}, volume = {7}, year = {2012}, month = {2012}, pages = {e43718}, abstract = {

Cellular differentiation programs are accompanied by large-scale changes in nuclear organization and gene expression. In this context, accompanying transitions in chromatin assembly that facilitates changes in gene expression and cell behavior in a developmental system are poorly understood. Here, we address this gap and map structural changes in chromatin organization during murine T-cell development, to describe an unusual heterogeneity in chromatin organization and associated functional correlates in T-cell lineage. Confocal imaging of DNA assembly in cells isolated from bone marrow, thymus and spleen reveal the emergence of heterogeneous patterns in DNA organization in mature T-cells following their exit from the thymus. The central DNA pattern dominated in immature precursor cells in the thymus whereas both central and peripheral DNA patterns were observed in na{\"\i}ve and memory cells in circulation. Na{\"\i}ve T-cells with central DNA patterns exhibited higher mechanical pliability in response to compressive loads in vitro and transmigration assays in vivo, and demonstrated accelerated expression of activation-induced marker CD69. T-cell activation was characterized by marked redistribution of DNA assembly to a central DNA pattern and increased nuclear size. Notably, heterogeneity in DNA patterns recovered in cells induced into quiescence in culture, suggesting an internal regulatory mechanism for chromatin reorganization. Taken together, our results uncover an important component of plasticity in nuclear organization, reflected in chromatin assembly, during T-cell development, differentiation and transmigration.

}, keywords = {Animals, Antigens, CD, Antigens, Differentiation, T-Lymphocyte, Bone Marrow Cells, Cell Lineage, Cell Movement, Cell Nucleus, Chromatin, DNA, Hematopoietic Stem Cells, Lectins, C-Type, Lymphocyte Activation, Mice, Microscopy, Confocal, Models, Biological, Models, Statistical, Sequence Analysis, DNA, Spleen, T-Lymphocytes}, issn = {1932-6203}, doi = {10.1371/journal.pone.0043718}, author = {Gupta, Soumya and Marcel, Nimi and Talwar, Shefali and Garg, Megha and R, Indulaxmi and Perumalsamy, Lakshmi R and Sarin, Apurva and Shivashankar, G V} } @article {714, title = {Distinct spatial and molecular features of notch pathway assembly in regulatory T cells.}, journal = {Sci Signal}, volume = {5}, year = {2012}, month = {2012 Jul 24}, pages = {ra53}, abstract = {

Variations in the spatial localization of signaling components and crosstalk among signaling cascades are mechanisms through which diversity in signaling networks is generated. The receptor Notch provides an example of regulation by spatial localization: In the canonical Notch signaling pathway, Notch is cleaved to produce the Notch intracellular domain (NICD, also known as NIC), which translocates to the nucleus to regulate gene expression. We describe a T cell receptor-dependent, non-nuclear distribution and function of the processed receptor Notch, which was associated with the improved survival of regulatory T cells (T(regs)) in vitro and in vivo and was compromised by T cell-specific deletion of Notch1. Unlike a nuclear-restricted mutant of NICD, mutant NICD that underwent nuclear export or was targeted to the plasma membrane protected Notch1(-/-) T(regs) from apoptosis induced by nutrient deprivation and oxidative stress. Notch signaling integrated with phosphatidylinositol 3-kinase signaling and mammalian target of rapamycin complex 2 (mTORC2) for this cell survival function. Biochemical and imaging approaches revealed a membrane-proximal complex containing NICD and the mTORC2 component Rictor, and this complex was stabilized by specific interactions with the Notch ligand Delta-like-1 and mediated the survival of T(regs). Together, our evidence for the spatial control of Notch and the crosstalk of Notch signaling with other pathways reveals coupling between the localization of Notch and diverse intracellular signaling pathways.

}, keywords = {Animals, Apoptosis, Blotting, Western, Carrier Proteins, Cell Line, Cell Membrane, Cell Survival, Flow Cytometry, Gene Knockout Techniques, Humans, Immunoprecipitation, Intercellular Signaling Peptides and Proteins, Mice, Mice, Inbred C57BL, Microscopy, Fluorescence, Phosphatidylinositol 3-Kinase, Rapamycin-Insensitive Companion of mTOR Protein, Receptor Cross-Talk, Receptor, Notch1, Signal Transduction, T-Lymphocytes, Regulatory, Trans-Activators, Transcription Factors}, issn = {1937-9145}, doi = {10.1126/scisignal.2002859}, author = {Perumalsamy, Lakshmi R and Marcel, Nimi and Kulkarni, Sneha and Radtke, Freddy and Sarin, Apurva} } @article {481, title = {Dysregulation of core components of SCF complex in poly-glutamine disorders. [Drosophila facility]}, journal = {Cell Death Dis}, volume = {3}, year = {2012}, month = {2012 Nov 22}, pages = {e428}, abstract = {

Poly-glutamine (polyQ) diseases are neurodegenerative disorders characterised by expanded CAG repeats in the causative genes whose proteins form inclusion bodies. Various E3 ubiquitin ligases are implicated in neurodegenerative disorders. We report that dysfunction of the SCF (Skp1-Cul1-F-box protein) complex, one of the most well-characterised ubiquitin ligases, is associated with pathology in polyQ diseases like Huntington{\textquoteright}s disease (HD) and Machado-Joseph disease (MJD). We found that Cullin1 (Cul1) and Skp1, core components of the SCF complex, are reduced in HD mice brain. A reduction in Cul1 levels was also observed in cellular HD model and fly models of both HD and MJD. We show that Cul1 is able to genetically modify mutant huntingtin aggregates because its silencing results in increased aggregate load in cultured cells. Moreover, we demonstrate that silencing dCul1 and dSkp1 in Drosophila results in increased aggregate load and enhanced polyQ-induced toxicity. Our results imply that reduced levels of SCF complex might contribute to polyQ disease pathology.

}, keywords = {Animals, Cullin Proteins, Drosophila, Female, Humans, Huntington Disease, Machado-Joseph Disease, Male, Mice, Mice, Transgenic, Peptides, SKP Cullin F-Box Protein Ligases}, issn = {2041-4889}, doi = {10.1038/cddis.2012.166}, author = {Bhutani, S and Das, A and Maheshwari, M and Lakhotia, S C and Jana, N R} } @article {723, title = {Germ cell abnormalities in streptozotocin induced diabetic mice do not correlate with blood glucose level.}, journal = {J Assist Reprod Genet}, volume = {29}, year = {2012}, month = {2012 Dec}, pages = {1405-13}, abstract = {

PURPOSE: To assess the effect of streptozotocin induced hyperglycemia on germ cell integrity, DNA ploidy and methylation status for a period of two spermatogenesis cycles in adult male Swiss albino mice.

METHODS: Streptozotocin injected mice were monitored for hyperglycemia at a regular interval for a period of 36 and 72\ days. The DNA integrity in epididymal spermatozoa was determined by the comet assay. Flow cytometric analysis was done in germ cells to assess the DNA ploidy. The global methylation analysis in germ cells was done by 5-methyl cytosine immunostaining.

RESULTS: Streptozotocin administration successfully resulted in hyperglycemic response which significantly affected serum testosterone level, sperm DNA integrity and DNA ploidy at the end of 36\ days. However, no changes were observed in either epididymal sperm concentration or germ cell methylation status. In contrast, at the end of 76\ days, although serum testosterone level, sperm DNA integrity and DNA ploidy status were unperturbed significantly in hyperglycemic group, the epididymal sperm concentration and methylation status of preleptotene/zygotene cells were significantly altered. Importantly, an attempt to find out the association between the blood glucose levels and the abnormalities in hyperglycemic group failed to demonstrate any correlation.

CONCLUSIONS: The germ cell abnormalities observed in hyperglycemic group could be interpreted as a primary effect of streptozotocin and not due to hyperglycemia. Our results call for further evaluation of streptozotocin before its application to study the hyperglycemic responses on male germ cells.

}, keywords = {Animals, Blood Glucose, Diabetes Mellitus, Experimental, DNA Methylation, Epididymis, Germ Cells, Humans, Hyperglycemia, Male, Mice, Ploidies, Sperm Count, Spermatogenesis, Spermatozoa, Streptozocin, Testosterone}, issn = {1573-7330}, doi = {10.1007/s10815-012-9873-0}, author = {Bose, Rohini and Adiga, Satish K and D{\textquoteright}Souza, Fiona and Salian, Sujith R and Uppangala, Shubhashree and Kalthur, Guruprasad and Jain, Navya and Radhakrishnan, Raghu A and Bhat, Nalini and Krishnamurthy, Hanumantappa and Kumar, Pratap} } @article {712, title = {An inhibitor of nonhomologous end-joining abrogates double-strand break repair and impedes cancer progression.}, journal = {Cell}, volume = {151}, year = {2012}, month = {2012 Dec 21}, pages = {1474-87}, abstract = {

DNA Ligase IV is responsible for sealing of double-strand breaks (DSBs) during nonhomologous end-joining (NHEJ). Inhibiting Ligase IV could result in amassing of DSBs, thereby serving as a strategy toward treatment of cancer. Here, we identify a molecule, SCR7 that inhibits joining of DSBs in cell-free repair system. SCR7 blocks Ligase IV-mediated joining by interfering with its DNA binding but not that of T4 DNA Ligase or Ligase I. SCR7 inhibits NHEJ in a Ligase IV-dependent manner within cells,\ and activates the intrinsic apoptotic pathway. More importantly, SCR7 impedes tumor progression in mouse models and when coadministered with DSB-inducing therapeutic modalities enhances their sensitivity significantly. This inhibitor to target NHEJ offers a strategy toward the treatment of cancer and improvement of existing regimens.

}, keywords = {Amino Acid Sequence, Animals, Cell Line, Tumor, Disease Models, Animal, DNA Breaks, Double-Stranded, DNA End-Joining Repair, DNA Ligase ATP, DNA Ligases, Drug Design, Drug Resistance, Neoplasm, Humans, Lymphocytes, Lymphoma, Male, Mice, Mice, Inbred BALB C, Mice, Nude, Models, Molecular, Molecular Sequence Data, Neoplasms, Protein Structure, Tertiary, Pyrimidines, Radiation Tolerance, Rats, Schiff Bases, Sequence Alignment}, issn = {1097-4172}, doi = {10.1016/j.cell.2012.11.054}, author = {Srivastava, Mrinal and Nambiar, Mridula and Sharma, Sheetal and Karki, Subhas S and Goldsmith, G and Hegde, Mahesh and Kumar, Sujeet and Pandey, Monica and Singh, Ram K and Ray, Pritha and Natarajan, Renuka and Kelkar, Madhura and De, Abhijit and Choudhary, Bibha and Raghavan, Sathees C} }