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231 results on '"Kotamraju, Srigiridhar"'

19. Mitochondria-targeted esculetin mitigates atherosclerosis in the setting of aging via the modulation of SIRT1-mediated vascular cell senescence and mitochondrial function in Apoe mice

Author

Karnewar, Santosh, primary, Pulipaka, Sriravali, additional, Katta, Sujana, additional, Panuganti, Devayani, additional, Neeli, Praveen Kumar, additional, Thennati, Rajamannar, additional, Jerald, Mahesh Kumar, additional, and Kotamraju, Srigiridhar, additional

Published
2022
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25. DOT1L regulates MTDH‐mediated angiogenesis in triple‐negative breast cancer: intermediacy of NF‐κB‐HIF1α axis.

Author

Neeli, Praveen Kumar, Sahoo, Shashikanta, Karnewar, Santosh, Singuru, Gajalakshmi, Pulipaka, Sriravali, Annamaneni, Sandhya, and Kotamraju, Srigiridhar

Subjects
TRIPLE-negative breast cancer, NF-kappa B, SEVERE combined immunodeficiency, NEOVASCULARIZATION, ONCOGENES, CHORIOALLANTOIS, CHICKS
Abstract

DOT1L, a specific H3K79 methyltransferase, has a tumour‐promoting role in various cancers, including triple‐negative breast cancer (TNBC). However, the molecular mechanism by which the deregulated DOT1L promotes cancer progression is unclear. Herein, we show that a significantly higher basal level of DOTL1 strongly correlates with MTDH, an oncogene, in clinical TNBC patient cohorts and mediates TNBC progression by enhancing MTDH‐induced angiogenesis. In parallel, severe combined immunodeficiency mice‐bearing MDA‐MB‐231 cells with MTDH‐Wt or MTDHΔ7 (spliced isoform of MTDH) overexpression constructs showed enhanced blood vessel formations at the tumour site in comparison with control groups. Selective inhibition of DOT1L by EPZ004777, a specific DOT1L inhibitor, or siDOT1L, significantly impaired MTDH‐induced proliferation, invasion and angiogenic markers expression in TNBC cells. ChIP assay revealed that Dot1L promotes MTDH‐Wt/Δ7 transcription by increasing H3K79me3 levels on its promoter. Dot1L depletion reversed this effect. Mechanistically, DOT1L‐induced MTDH caused enhanced nuclear factor kappa B (NF‐κB) occupancy on the hypoxia‐inducible factor1α (HIF1α) promoter and increased its transcription, leading to elevated levels of proangiogenic mediators in TNBC cells. Moreover, the condition media obtained from MDA‐MB‐231 cells stably expressing either MTDH‐Wt or MTDHΔ7 treated with EPZ004777 or Bay‐11‐7082 (NF‐κB inhibitor) or FM19G11 (HIF1α inhibitor) significantly inhibited MTDH‐induced tube formation in human umbilical vein endothelial cells, rat aortic ring sprouting and vessel formations by chick chorioallantoic membrane assay mimicking physiological angiogenic vasculature. Collectively, our findings reveal a novel epigenetic regulation of MTDH by DOTL1, which drives angiogenesis, and that the therapeutic disruption of the DOT1L‐MTDH‐NF‐κB‐HIF1α axis may have usefulness in the management of TNBC. [ABSTRACT FROM AUTHOR]

Published
2023
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34. Novel 1,2,3-Triazole-Functionalized 1,2-Benzothiazine 1,1-Dioxide Derivatives: Regioselective Synthesis, Biological Evaluation and Docking Studies

Author

Banda Narsaiah, Yedla Poornachandra, Gopoju Raja, Kuchukulla Ratnakarreddy, Nagiri Ravi Kumar, Kotamraju Srigiridhar, Nanubolu Jagadeesh Babu, Gunda Shravan Kumar, Desireddy Krishna Swaroop, and Chityal Ganesh Kumar

Subjects
1,2,3-Triazole, 010405 organic chemistry, Baker–Venkataraman rearrangement, Regioselectivity, General Chemistry, Benzothiazine, 01 natural sciences, Combinatorial chemistry, 0104 chemical sciences, 010404 medicinal & biomolecular chemistry, chemistry.chemical_compound, chemistry, Docking (molecular), Biological evaluation
Published
2018
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37. Reactive oxygen species induce reversible PECAM-1 tyrosine phosphorylation and SHP-2 binding

Author

Maas, Matthias, Wang, Ronggang, Paddock, Cathy, Kotamraju, Srigiridhar, Kalyanaraman, Balaraman, Newman, Peter J., and Newman, Debra K.

Subjects
Tyrosine -- Research, Biological sciences
Abstract

Platelet endothelial cell adhesion molecule-1 (PECAM-1, CD31) functions to control the activation and survival of the cells on which it is expressed. Many of the regulatory functions of PECAM-1 are dependent on its tyrosine phosphorylation and subsequent recruitment of the Src homology (SH2) domain containing protein tyrosine phosphatase SHP-2. The recent demonstration that PECAM-1 tyrosine phosphorylation occurs in cells exposed to the reactive oxygen species hydrogen peroxide ([H.sub.2][O.sub.2]) suggested that this form of oxidative stress may also support PECAM-1/SHP-2 complex formation. In the present study, we show that PECAM-1 tyrosine phosphorylation in response to exposure of cells to [H.sub.2][O.sub.2] is reversible, involves a shift in the balance between kinase and phosphatase activities, and supports binding of SHP-2 and recruitment of this phosphatase to cell-cell borders. We speculate, however, that the unique ability of [H.sub.2][O.sub.2] to reversibly oxidize the reactive site cysteine residues of protein tyrosine phosphatases may result in transient inactivation of the SHP-2 that is bound to PECAM-1 under these conditions. Finally, we provide evidence that PECAM-1 tyrosine phosphorylation and SHP-2 binding in endothelial cells requires exposure to an 'oxidative burst' of [H.sub.2][O.sub.2], but that exposure of these cells to sufficiently high concentrations of [H.sub.2][O.sub.2] for a sufficiently long period of time abrogates binding of SHP-2 to tyrosine-phosphorylated PECAM-1. These findings support a role for PECAM-1 as a sensor of oxidative stress, perhaps most importantly during the process of inflammation. phosphotyrosine; hydrogen peroxide; SHP-2; CD31

Published
2003

38. Nitric oxide inhibits [H.sub.2][O.sub.2]-induced transferrin receptor-dependent apoptosis in endothelial cells: role of ubiquitin-proteasome pathway

Author

Kotamraju, Srigiridhar, Tampo, Yoshiko, Keszler, Agnes, Chitambar, Christopher R., Joseph, Joy, Haas, Arthur L., and Kalyanaraman, B.

Subjects
Cells -- Research, Nitric oxide -- Research, Science and technology
Abstract

We investigated here the mechanism of cytoprotection of nitric oxide ([sup.*]NO) in bovine aortic endothelial cells treated with [H.sub.2][O.sub.2]. NONOates were used as [sup.*]NO donors that released [sup.*]NO slowly at a well defined rate in the extracellular and intracellular milieus. [H.sub.2][O.sub.2]-mediated intracellular dichlorofluorescein fluorescence and apoptosis were enhanced by the transferrin receptor (TfR)-mediated iron uptake. [sup.*]NO inhibited the TfR-mediated iron uptake, dichlorofluorescein fluorescence, and apoptosis in [H.sub.2][O.sub.2]-treated cells. [sup.*]NO increased the proteasomal activity and degradation of nitrated TfR via ubiquitination. [N.sup.[omega]-nitro-L-arginine methyl ester, a nonspecific inhibitor of endogenous [sup.*]NO biosynthesis, decreased the trypsin-like activity of 26S proteasome. [sup.*]NO, by activating proteolysis, mitigates TfR-dependent iron uptake, dichlorodihydrofluorescein oxidation, and apoptosis in [H.sub.2][O.sub.2]-treated bovine aortic endothelial cells. The relevance of biological nitration on redox signaling is discussed.

Published
2003

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