Shashi Bhushan - Academia.edu (original) (raw)

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Bhim P Singh

National Institute of Food Technology Entrepreneurship and Management (NIFTEM)

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Papers by Shashi Bhushan

Alternaria alternata Capsaicin Alternariol-10-methyl ether (MRM)-LC–ESI–MS/MS Anti-cancer a b s t... more Alternaria alternata Capsaicin Alternariol-10-methyl ether (MRM)-LC–ESI–MS/MS Anti-cancer a b s t r a c t Alternaria alternata, an endophytic fungus capable of producing capsaicin (1) was isolated from Capsicum annum. The endophyte was found to produce capsaicin upto three generations. Upscaling of the fermen-tation broth led to the isolation of one known and one compound characterized as 2,4-di-tert-butyl phenol (2) and alternariol-10-methyl ether (3) respectively. Compound 1 and 3 were identified and quan-tified using liquid chromatography-electrospray ionization tandem mass spectrometry (LC–ESI–MS/MS) system through multiple reaction monitoring (MRM). Furthermore, compound 3 displayed a range of cytotoxicity against a panel of human cancer cell lines and was found to induce apoptosis evidenced by Hoechst staining and loss of mitochondrial-membrane potential in HL-60 cells.

Molecular Cell, 2010

Specific regulatory nascent chains establish direct interactions with the ribosomal tunnel, leadi... more Specific regulatory nascent chains establish direct interactions with the ribosomal tunnel, leading to translational stalling. Despite a wealth of biochemical data, structural insight into the mechanism of translational stalling in eukaryotes is still lacking. Here we use cryo-electron microscopy to visualize eukaryotic ribosomes stalled during the translation of two diverse regulatory peptides: the fungal arginine attenuator peptide (AAP) and the human cytomegalovirus (hCMV) gp48 upstream open reading frame 2 (uORF2). The C terminus of the AAP appears to be compacted adjacent to the peptidyl transferase center (PTC). Both nascent chains interact with ribosomal proteins L4 and L17 at tunnel constriction in a distinct fashion. Significant changes at the PTC were observed: the eukaryotic-specific loop of ribosomal protein L10e establishes direct contact with the CCA end of the peptidyl-tRNA (P-tRNA), which may be critical for silencing of the PTC during translational stalling. Our findings provide direct structural insight into two distinct eukaryotic stalling processes.

Omics: a journal of integrative biology

Abstract Network biology-inspired approaches could be used effectively in probing regulatory proc... more Abstract Network biology-inspired approaches could be used effectively in probing regulatory processes by which small molecules intervene with disease mechanisms. The present study aims at identification of key targets of type 2 diabetes mellitus (T2DM) by network analysis of the underlying protein interactome, and probing for mechanisms by which phloridzin could be critical at altering the disease phenotype. Towards this goal, we constructed a protein-protein interaction network associated with T2DM, starting from candidate genes and systems-level interactions data available. The relevance of the network constructed was verified with the help of gene ontology, node deletion, and biological essentiality studies. Using a network analysis method, MAPK1, EP300, and SMAD2 were identified as the most central proteins of potential therapeutic value. Phloridzin, a known antidiabetic agent, potentially interacts with proteins central to T2DM mechanisms. The structural understanding of inter...

Chemistry of Natural Compounds

Chemical investigation of industrial apple pomace waste has led to the isolation of two water-sol... more Chemical investigation of industrial apple pomace waste has led to the isolation of two water-soluble polysaccharides (AS-3 and AS-5). Both polysaccharides were identified as arabinans on the basis of GC-MS, IR, 1D, 2D NMR, and MALDI-TOF-MS studies. GC-MS analysis of alditol acetate derivatives of AS-3 suggested the presence of arabinose and glucose sugars in the ratio of 4:1, whereas AS-5 was composed of only arabinose. The structure of AS-3 was identified as circular with three arabinose and one glucose in the circle and one arabinose unit branched at the C-4 position of the arabinose. AS-5 consists of four arabinose units, out of which three were linked linearly through 1 → 5 and 1 → 3 linkage and one in the side chain linked through 1 → 2 linkage.

European Journal of Cancer, 2014

Cell Death and Disease, 2013

Angiogenesis has a key role in the tumor progression and metastasis; targeting endothelial cell p... more Angiogenesis has a key role in the tumor progression and metastasis; targeting endothelial cell proliferation has emerged as a promising therapeutic strategy for the prevention of cancer. Previous studies have revealed a complex association between the process of angiogenesis and autophagy and its outcome on tumorigenesis. Autophagy, also known as type-II cell death, has been identified as an alternative way of cell killing in apoptotic-resistant cancer cells. However, its involvement in chemoresistance and tumor promotion is also well known. In this study, we used a derivate of natural product magnolol (Ery5), a potent autophagy inducer, to study the association between the autophagy and angiogenesis in both in vitro and in vivo model system. We found that the robust autophagy triggered by Ery5, inhibited angiogenesis and caused cell death independent of the apoptosis in human umbilical cord vein endothelial cells and PC-3 cells. Ery5 induced autophagy effectively inhibited cell proliferation, migration, invasion and tube formation. We further demonstrated that Ery5-mediated autophagy and subsequent inhibition of angiogenesis was reversed when autophagy was inhibited through 3-methyl adenine and knocking down of key autophagy proteins ATG7 and microtubule-associated protein light chain 3. While evaluating the negative regulation of autophagy on angiogenesis, it was interesting to find that angiogenic environment produced by the treatment of VEGF and CoCl2 remarkably downregulated the autophagy and autophagic cell death induced by Ery5. These studies, while disclosing the vital role of autophagy in the regulation of angiogenesis, also suggest that the potent modulators of autophagy can lead to the development of effective therapeutics in apoptosis-resistant cancer.

Both authors contributed equally to this work.

Alternaria alternata Capsaicin Alternariol-10-methyl ether (MRM)-LC–ESI–MS/MS Anti-cancer a b s t... more Alternaria alternata Capsaicin Alternariol-10-methyl ether (MRM)-LC–ESI–MS/MS Anti-cancer a b s t r a c t Alternaria alternata, an endophytic fungus capable of producing capsaicin (1) was isolated from Capsicum annum. The endophyte was found to produce capsaicin upto three generations. Upscaling of the fermen-tation broth led to the isolation of one known and one compound characterized as 2,4-di-tert-butyl phenol (2) and alternariol-10-methyl ether (3) respectively. Compound 1 and 3 were identified and quan-tified using liquid chromatography-electrospray ionization tandem mass spectrometry (LC–ESI–MS/MS) system through multiple reaction monitoring (MRM). Furthermore, compound 3 displayed a range of cytotoxicity against a panel of human cancer cell lines and was found to induce apoptosis evidenced by Hoechst staining and loss of mitochondrial-membrane potential in HL-60 cells.

Molecular Cell, 2010

Specific regulatory nascent chains establish direct interactions with the ribosomal tunnel, leadi... more Specific regulatory nascent chains establish direct interactions with the ribosomal tunnel, leading to translational stalling. Despite a wealth of biochemical data, structural insight into the mechanism of translational stalling in eukaryotes is still lacking. Here we use cryo-electron microscopy to visualize eukaryotic ribosomes stalled during the translation of two diverse regulatory peptides: the fungal arginine attenuator peptide (AAP) and the human cytomegalovirus (hCMV) gp48 upstream open reading frame 2 (uORF2). The C terminus of the AAP appears to be compacted adjacent to the peptidyl transferase center (PTC). Both nascent chains interact with ribosomal proteins L4 and L17 at tunnel constriction in a distinct fashion. Significant changes at the PTC were observed: the eukaryotic-specific loop of ribosomal protein L10e establishes direct contact with the CCA end of the peptidyl-tRNA (P-tRNA), which may be critical for silencing of the PTC during translational stalling. Our findings provide direct structural insight into two distinct eukaryotic stalling processes.

Omics: a journal of integrative biology

Abstract Network biology-inspired approaches could be used effectively in probing regulatory proc... more Abstract Network biology-inspired approaches could be used effectively in probing regulatory processes by which small molecules intervene with disease mechanisms. The present study aims at identification of key targets of type 2 diabetes mellitus (T2DM) by network analysis of the underlying protein interactome, and probing for mechanisms by which phloridzin could be critical at altering the disease phenotype. Towards this goal, we constructed a protein-protein interaction network associated with T2DM, starting from candidate genes and systems-level interactions data available. The relevance of the network constructed was verified with the help of gene ontology, node deletion, and biological essentiality studies. Using a network analysis method, MAPK1, EP300, and SMAD2 were identified as the most central proteins of potential therapeutic value. Phloridzin, a known antidiabetic agent, potentially interacts with proteins central to T2DM mechanisms. The structural understanding of inter...

Chemistry of Natural Compounds

Chemical investigation of industrial apple pomace waste has led to the isolation of two water-sol... more Chemical investigation of industrial apple pomace waste has led to the isolation of two water-soluble polysaccharides (AS-3 and AS-5). Both polysaccharides were identified as arabinans on the basis of GC-MS, IR, 1D, 2D NMR, and MALDI-TOF-MS studies. GC-MS analysis of alditol acetate derivatives of AS-3 suggested the presence of arabinose and glucose sugars in the ratio of 4:1, whereas AS-5 was composed of only arabinose. The structure of AS-3 was identified as circular with three arabinose and one glucose in the circle and one arabinose unit branched at the C-4 position of the arabinose. AS-5 consists of four arabinose units, out of which three were linked linearly through 1 → 5 and 1 → 3 linkage and one in the side chain linked through 1 → 2 linkage.

European Journal of Cancer, 2014

Cell Death and Disease, 2013

Angiogenesis has a key role in the tumor progression and metastasis; targeting endothelial cell p... more Angiogenesis has a key role in the tumor progression and metastasis; targeting endothelial cell proliferation has emerged as a promising therapeutic strategy for the prevention of cancer. Previous studies have revealed a complex association between the process of angiogenesis and autophagy and its outcome on tumorigenesis. Autophagy, also known as type-II cell death, has been identified as an alternative way of cell killing in apoptotic-resistant cancer cells. However, its involvement in chemoresistance and tumor promotion is also well known. In this study, we used a derivate of natural product magnolol (Ery5), a potent autophagy inducer, to study the association between the autophagy and angiogenesis in both in vitro and in vivo model system. We found that the robust autophagy triggered by Ery5, inhibited angiogenesis and caused cell death independent of the apoptosis in human umbilical cord vein endothelial cells and PC-3 cells. Ery5 induced autophagy effectively inhibited cell proliferation, migration, invasion and tube formation. We further demonstrated that Ery5-mediated autophagy and subsequent inhibition of angiogenesis was reversed when autophagy was inhibited through 3-methyl adenine and knocking down of key autophagy proteins ATG7 and microtubule-associated protein light chain 3. While evaluating the negative regulation of autophagy on angiogenesis, it was interesting to find that angiogenic environment produced by the treatment of VEGF and CoCl2 remarkably downregulated the autophagy and autophagic cell death induced by Ery5. These studies, while disclosing the vital role of autophagy in the regulation of angiogenesis, also suggest that the potent modulators of autophagy can lead to the development of effective therapeutics in apoptosis-resistant cancer.

Both authors contributed equally to this work.

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