Ganta V Chaitanya

Publications (22) View all

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  Available from: Ganta V Chaitanya

  Article: Focus on carbon monoxide: a modulator of neutrophil oxidants and elastase spatial localization?

  V C Ganta, J S Alexander
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  ABSTRACT: The protective roles of CO in various patho-physiological conditions are rapidly expanding. We are only beginning to understand how this gaseous signal molecule exerts such diverse cell and model specific effects. CO interacts in NO signaling, and is an activator of guanylate cyclase/PKG. However several downstream molecular signals mediated by CO (p38-MAPK, ERK1/2) may be oxidant dependent. How CO affects these and other signaling pathways in PMN is not well understood, but is of immense clinical interest. The present study by Mizoguchi et al. describes cell-specific roles of CORM-3 derived CO in protecting the lung against neutrophil dependent septic injury. Importantly, CO donors appear to only affect neutrophils and may involve a novel mechanism whereby CO induces the shedding of neutrophil elastase from the active front of the neutrophil. Shedding of this protease, and neutrophil rolling and adhesion were also inhibited by CO in a novel fashion involving elevation of ROS species. The involvement of various cellular ROS production sites (especially mitochondria); their mechanisms and the potential therapeutic benefit of CO donors like CORM-3 are discussed. Key words: elastase, hemoxygenase, lung injury, CO.
  AJP Heart and Circulatory Physiology 08/2009; 297(3):H902-4. · 3.71 Impact Factor
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  Article: Discovery of transcriptional programs in cerebral ischemia by in silico promoter analysis.

  Dirk A Ridder, Svetlana Bulashevska, Ganta Vijay Chaitanya, Phanithi Prakash Babu, Benedikt Brors, Roland Eils, Armin Schneider, Markus Schwaninger
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  ABSTRACT: In stroke, gene transcription plays a central role in processes such as neuroinflammation and neuroregeneration. To predict new transcriptional regulatory mechanisms in cerebral ischemia, we applied a computational approach combining two kinds of information: the results of a microarray analysis in a mouse model of stroke and in silico detection of transcription factor (TF) binding sites in promoter regions of the genes on the array. By using a discriminative logistic regression model, we identified binding sites significantly associated with the up-regulation of genes. Out of 356 TF binding sites defined in TRANSFAC, we could link 32 to gene up-regulation in cerebral ischemia. These sites bind both TFs with an established and a so far unknown role in cerebral ischemia. To evaluate the results further we investigated whether two TFs, CCAAT/enhancer binding protein beta (C/EBP beta) and vitamin D receptor (VDR), are activated as predicted. Immunohistochemistry demonstrated that C/EBP beta and VDR translocated to the nucleus in cerebral ischemia. Chromatin immunoprecipitation revealed increased binding of C/EBP beta to the promoter of its target gene saa3. In addition, we found evidence for the up-regulation of VDR in brain samples from human stroke patients. These results confirm the activation of C/EBP beta and VDR in cerebral ischemia. Thus, our in silico analysis may provide additional information on transcriptional regulation in stroke and suggests several novel transcriptional programs for further exploration.
  Brain research 04/2009; 1272:3-13. · 2.46 Impact Factor
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  Article: Granzyme-b mediated cell death in the spinal cord-injured rat model.

  Ganta Vijay Chaitanya, Mayuri Kolli, Phanithi Prakash Babu
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  ABSTRACT: Spinal cord injury initiates a complex series of inflammatory and immune responses including the influx of monocytes, macrophages, T-cells, NK cells and so on, into the injured area. In the present study, we found a significant increase in the levels of granzyme-b (gra-b) from the first day after the transection until the third day, with decrease in intensity thereafter. The chemokine IP-10/CXCL10 was also found to be elevated along with gra-b correlating with the infiltration of CD-8(+) cytotoxic T lymphocytes (CTLs) into the injured spinal cord. We observed an increase in the levels of the 64 kDa poly ADP ribose polymerase fragment, known to be a signature fragment produced by gra-b. Localization of gra-b in TUNEL positive neurons indicates that gra-b might play a crucial role in neuronal death and contributes to the pathophysiology of spinal cord injury.
  Neuropathology 01/2009; 29(3):270-9. · 2.02 Impact Factor
• Article: Expanding roles of glutamate receptors in neurovascular regulation.

  J S Alexander, Chaitanya V Ganta
  Vascular Pharmacology 03/2012; 57(1):1-2. · 1.99 Impact Factor
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  Available from: Ganta V Chaitanya

  Article: Multiple apoptogenic proteins are involved in the nuclear translocation of Apoptosis Inducing Factor during transient focal cerebral ischemia in rat.

  Ganta Vijay Chaitanya, Phanithi Prakash Babu
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  ABSTRACT: Apoptosis Inducing Factor is a mitochondrial protein which upon translocation to nucleus causes large scale DNA fragmentation. The stimulus for the cytosolic release and nuclear translocation for this protein still remains to be understood. The role of calpains, cathepsin-b, Poly ADP (ribose) Polymerase and granzyme-b in the nuclear translocation of AIF has been investigated in the pathology of cerebral ischemia. Calpains, cathepsin-b and PARP-1 which were mostly confined to cytosol, lysosomes and nucleus respectively were found to be elevated in the mitochondrial fraction interacting with AIF in the western blot analysis and double immunofluorescence analysis. Western blot and immunohistochemical analysis revealed elevated levels of granzyme-b secreted by cytotoxic T lymphocytes and natural killer cells in the infarct of ischemic mouse brain. Co-immunoprecipitation revealed and western blot analysis the interaction and break down of Heat Shock Protein-70 an endogenous inhibitor of AIF into signature fragments by granzyme-b facilitating the nuclear translocation of AIF. Break down of HSP-70 correlated with the nuclear translocation of AIF observed in western and immunohistochemical analysis. These results indicate that multiple proteases were involved in the nuclear translocation of AIF during the pathology of cerebral ischemia.
  Brain research 11/2008; 1246:178-90. · 2.46 Impact Factor