School Of Basic And Applied Sciences

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Author: search.filters.author.Mantha, Anil K.Has files: Yes

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    Oxidative stress stimulates invasive potential in rat C6 and human U-87 MG glioblastoma cells via activation and cross-talk between PKM2, ENPP2 and APE1 enzymes.
    (Springer, 2018) Cholia, Ravi P.; Dhiman, Monisha; Kumar, Raj; Mantha, Anil K.
    Maintaining genomic integrity is essential for cell survival and viability. Reactive oxygen species (ROS) overproduction results in oxidative stress leading to the genomic instability via generation of small base lesions in DNA and these unrepaired DNA damages lead to various cellular consequences including cancer. Recent data support the concept "oxidative stress is an indispensable participant in fostering proliferation, survival, and migration" in various cancer cell types including glioblastoma cells. In this study we demonstrate that treatment of non-cytotoxic doses of oxidants such as amyloid beta [Aβ(25-35)] peptide, glucose oxidase (GO), and hydrogen peroxide (H2O2) for 24 h and 48 h time points found to increase the expression level and activity of a multifunctional enzyme Apurinic/apyrimidinic endonuclease (APE1), a key enzyme of base excision repair (BER) pathway which takes care of base damages; and also resulted in modulation in the expression levels of downstream BER-pathway enzymes viz. PARP-1, XRCC1, DNA polβ, and ligase IIIα was observed upon oxidative stress in C6 and U-87 MG cells. Oxidants treatment to the C6 and U-87 MG cells also resulted in an elevation in the intracellular expression of glycolytic pathway enzyme Pyruvate kinase M2 (PKM2) and the metastasis inducer protein Ectonucleotide pyrophosphatase/phosphodiesterase 2 (ENPP2) as analyzed using Western blotting and Immunofluorescence microscopic studies. Our study also reports that oxidative stress induced for 24 h and 48 h in C6 and U-87 MG cells resulted in extracellular secretion of APE1 and ENPP2 as analyzed using Western blotting in conditioned media. However, the biological significance of extracellular secreted APE1 remains elusive. Oxidative stress also elevated the ENPP2's LysoPLD activity in conditioned media of C6 and U-87 MG cells. Our results also demonstrate that oxidative stress affects the expression level and localization of APE1, PKM2, and ENPP2 in C6 and U-87 MG cells. As evidenced by the colocalization pattern at 24 h and 48 h time points, it can be attributed that oxidative stress mediates crosstalk between APE1, PKM2, and ENPP2. In addition, when C6 and U-87 MG cells were treated with lysophosphatidic acid (LPA), a bioactive lipid that negatively regulates ENPP2's LysoPLD activity at 10 μM concentration, demonstrated strong migratory potential in C6 and U-87 MG cells, and also induced migration upon oxidative stress. Altogether, the findings demonstrate the potential of C6 and U-87 MG cells to utilize three proteins viz. APE1, PKM2, and ENPP2 towards migration and survival of gliomas. Thus the knowledge on oxidative stress induced APE1's interaction with PKM2 and ENPP2 opens a new channel for the therapeutic target(s) for gliomas.
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    Anticancer activity of dihydropyrazolo[1,5-c]quinazolines against rat C6 glioma cells via inhibition of topoisomerase II.
    (Wiley, 2018) Kaur, G; Cholia, RP; Joshi, G; Amrutkar, SM; Kalra, S; Mantha, Anil K.; Banerjee, UC; Kumar, R.
    The design and synthesis of dihydropyrazolo[1,5‐c]quinazolines (1a–h) as human topoisomerase II (TopoII) catalytic inhibitors are reported. The compounds were investigated for their antiproliferative activity against the C6 rat glial cell line. Two compounds, 1b and 1h, were found to be potent cytotoxic agents against glioma cells and exerted selective TopoII inhibitory activity. Furthermore, the compounds induced alterations in reactive oxygen species levels as measured by DCFDA assay and were found to induce cell cycle arrest at the G1 phase at lower concentrations and profound apoptosis at higher concentrations. The interaction of selected investigational molecules with TopoII was further corroborated by molecular modeling.
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    Synthesis, biological evaluation and molecular modeling studies of phenyl-/benzhydrylpiperazine derivatives as potential MAO inhibitors.
    (Elsevier, 2018) Kumar, Bhupinder; Sheetal; Mantha, Anil K.; Kumar, Vinod
    Monoamine oxidase inhibitors (MAOIs) are potential drug candidates for the treatment of various neurological disorders like Parkinson's disease, Alzheimer's disease and depression. In the present study, two series of 4-substituted phenylpiperazine and 1-benzhydrylpiperazine (1-21) derivatives were synthesized and screened for their MAO-A and MAO-B inhibitory activity using Amplex Red assay. Most of the synthesized compounds were found selective for MAO-B isoform except compounds 3, 7, 8, 9 and 13 (MAO-A selective) while compound 11 was non-selective. In the current series, compound 12 showed most potent MAO-B inhibitor activity with IC50 value of 80 nM and compound 7 was found to be most potent MAO-A inhibitor with IC50 value of 120 nM and both the compounds were found reversible inhibitors. Compound 8 was found most selective MAO-A inhibitor while compound 20 was found most selective inhibitor for MAO-B isoform. In the cytotoxicity evaluation, all the compounds were found non-toxic to SH-SY5Y and IMR-32 cells at 25 µM concentration. In the ROS studies, compound 8 (MAO-A inhibitor) reduced the ROS level by 51.2% while compound 13 reduced the ROS level by 61.81%. In the molecular dynamic simulation studies for 30 ns, compound 12 was found quite stable in the active cavity of MAO-B. Thus, it can be concluded that phenyl- and 1-benzhydrylpiperazine derivatives are promising MAO inhibitors and can act as a lead to design potent, and selective MAO inhibitors for the treatment of various neurological disorders.
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    Inflammatory response of gliadin protein isolated from various wheat varieties on human intestinal cell line
    (Academic Press, 2018) Gupta, K.B.; Upadhyay, S.; Saini, R.G.; Mantha, Anil K.; Dhiman, Monisha
    Wheat protein contributes a significant part in human diet, apart from its well-known nutritional values, wheat gluten/gliadin proteins are also responsible for the many allergic/inflammatory diseases and chronic inflammation in the small intestine may cause diarrhea and malabsorption, in a specific population of individuals. In the present study, the antigenic characteristics of twelve wheat varieties of diverse origin namely C273, C281, C286, C306, C518, C591, Agra Local, 9D, 8A, Raj4229, HD3027, NP824 released during 1920?2012 were evaluated. Gliadin proteins from these varieties were tested on human colon cancer cell line HCT116 to assess their effect on inflammation, oxidative and nitrosative stress, pro-inflammatory cytokines. The results show that these wheat varieties induced high levels of ROS/RNS and MPO activity which was further supported by the increase in the mRNA levels of a cytokine such as IL-1? and IL-15. It can be concluded that gliadin from these wheat varieties is suggested to act as a potential antigen by enhancing the level of inflammation irrespective of their year of release and origin which if not controlled may lead to the initiation of celiac disease in genetically susceptible individuals or may be responsible for other wheat protein intolerance associated diseases. ? 2018 Elsevier Ltd
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    Anticancer activity of dihydropyrazolo[1,5-c]quinazolines against rat C6 glioma cells via inhibition of topoisomerase II
    (Wiley-VCH Verlag, 2018) Kaur, G.; Cholia, R.P.; Joshi, G.; Amrutkar, S.M.; Kalra, S.; Mantha, Anil K.; Banerjee, U.C.; Kumar, Raj
    The design and synthesis of dihydropyrazolo[1,5-c]quinazolines (1a?h) as human topoisomerase II (TopoII) catalytic inhibitors are reported. The compounds were investigated for their antiproliferative activity against the C6 rat glial cell line. Two compounds, 1b and 1h, were found to be potent cytotoxic agents against glioma cells and exerted selective TopoII inhibitory activity. Furthermore, the compounds induced alterations in reactive oxygen species levels as measured by DCFDA assay and were found to induce cell cycle arrest at the G1 phase at lower concentrations and profound apoptosis at higher concentrations. The interaction of selected investigational molecules with TopoII was further corroborated by molecular modeling. ? 2018 Deutsche Pharmazeutische Gesellschaft
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    Synthesis, biological evaluation and molecular modeling studies of phenyl-/benzhydrylpiperazine derivatives as potential MAO inhibitors
    (Academic Press Inc., 2018) Kumar, Bhupinder; Sheetal; Mantha, Anil K.; Kumar, Vinod
    Monoamine oxidase inhibitors (MAOIs) are potential drug candidates for the treatment of various neurological disorders like Parkinson's disease, Alzheimer's disease and depression. In the present study, two series of 4-substituted phenylpiperazine and 1-benzhydrylpiperazine (1?21) derivatives were synthesized and screened for their MAO-A and MAO-B inhibitory activity using Amplex Red assay. Most of the synthesized compounds were found selective for MAO-B isoform except compounds 3, 7, 8, 9 and 13 (MAO-A selective) while compound 11 was non-selective. In the current series, compound 12 showed most potent MAO-B inhibitor activity with IC50 value of 80 nM and compound 7 was found to be most potent MAO-A inhibitor with IC50 value of 120 nM and both the compounds were found reversible inhibitors. Compound 8 was found most selective MAO-A inhibitor while compound 20 was found most selective inhibitor for MAO-B isoform. In the cytotoxicity evaluation, all the compounds were found non-toxic to SH-SY5Y and IMR-32 cells at 25 ?M concentration. In the ROS studies, compound 8 (MAO-A inhibitor) reduced the ROS level by 51.2% while compound 13 reduced the ROS level by 61.81%. In the molecular dynamic simulation studies for 30 ns, compound 12 was found quite stable in the active cavity of MAO-B. Thus, it can be concluded that phenyl- and 1-benzhydrylpiperazine derivatives are promising MAO inhibitors and can act as a lead to design potent, and selective MAO inhibitors for the treatment of various neurological disorders. ? 2018 Elsevier Inc.
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    APE1 modulates cellular responses to organophosphate pesticide-induced oxidative damage in non-small cell lung carcinoma A549 cells
    (Springer New York LLC, 2018) Thakur, Shweta; Dhiman, Monisha; Mantha, Anil K.
    Monocrotophos (MCP) and chlorpyrifos (CP) are widely used organophosphate pesticides (OPPs), speculated to be linked with human pathologies including cancer. Owing to the fact that lung cells are most vulnerable to the environmental toxins, the development and progression of lung cancer can be caused by the exposure of OPPs. The present study investigates the oxidative DNA damage response evoked by MCP and CP in human non-small cell lung carcinoma A549 cells. A549 cells were exposed to MCP and CP; cytotoxicity and reactive oxygen species (ROS) generation were measured to select the non-toxic dose. In order to establish whether MCP and CP can initiate the DNA repair and cell survival signalling pathways in A549 cells, qRT-PCR and Western blotting techniques were used to investigate the mRNA and protein expression levels of DNA base excision repair (BER)-pathway enzymes and transcription factors (TFs) involved in cell survival mechanisms. A significant increase in cell viability and ROS generation was observed when exposed to low and moderate doses of MCP and CP at different time points (24, 48 and 72?h) studied. A549 cells displayed a dose-dependent accumulation of apurinic/apyrimidinic (AP) sites after 24?h exposure to MCP advocating for the activation of AP endonuclease-mediated DNA BER-pathway. Cellular responses to MCP- and CP-induced oxidative stress resulted in an imbalance in the mRNA and protein expression of BER-pathway enzymes, viz. PARP1, OGG1, APE1, XRCC1, DNA pol ? and DNA ligase III ? at different time points. The treatment of OPPs resulted in the upregulation of TFs, viz. Nrf2, c-jun, phospho-c-jun and inducible nitric oxide synthase. Immunofluorescent confocal imaging of A549 cells indicated that MCP and CP induces the translocation of APE1 within the cytoplasm at an early 6?h time point, whereas it promotes nuclear localization after 24?h of treatment, which suggests that APE1 subcellular distribution is dynamically regulated in response to OPP-induced oxidative stress. Furthermore, nuclear colocalization of APE1 and the TF c-jun was observed in response to the treatment of CP and MCP for different time points in A549 cells. Therefore, in this study we demonstrate that MCP- and CP-induced oxidative stress alters APE1-dependent BER-pathway and also mediates cell survival signalling mechanisms via APE1 regulation, thereby promoting lung cancer cell survival and proliferation. ? 2017, Springer Science+Business Media, LLC.
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    Curcumin revitalizes Amyloid beta (25–35)-induced and organophosphate pesticides pestered neurotoxicity in SH-SY5Y and IMR-32 cells via activation of APE1 and Nrf2
    (Springer, 2017) Sarkar, Bibekananda; Dhiman, Monisha; Mittal, Sunil; Mantha, Anil K.
    Amyloid beta (Aβ) peptide deposition is the primary cause of neurodegeneration in Alzheimer’s disease (AD) pathogenesis. Several reports point towards the role of pesticides in the AD pathogenesis, especially organophosphate pesticides (OPPs). Monocrotophos (MCP) and Chlorpyrifos (CP) are the most widely used OPPs. In this study, the role of MCP and CP in augmenting the Aβ-induced oxidative stress associated with the neurodegeneration in AD has been assessed in human neuroblastoma IMR-32 and SH-SY5Y cell lines. From the cell survival assay, it was observed that MCP and CP reduced cell survival both dose- and time-dependently. Nitro blue tetrazolium (NBT) based assay for determination of intracellular reactive oxygen species (ROS) demonstrated that Aβ(25–35), MCP or CP produce significant oxidative stress alone or synergistically in IMR-32 and SH-SY5Y cells, while pretreatment of curcumin reduced ROS levels significantly in all treatment combinations. In this study, we also demonstrate that treatment of Aβ(25–35) and MCP upregulated inducible nitric oxide synthase (iNOS/NOS2) whereas, no change was observed in neuronal nitric oxide synthase (nNOS/NOS1), but down-regulation of the nuclear factor erythroid 2-related factor 2 (Nrf2) level was observed. While curcumin pretreatment resulted in upregulation of iNOS and Nrf2 proteins. Also, the expression of key DNA repair enzymes APE1, DNA polymerase beta (Pol β), and PARP1 were found to be downregulated upon treatment with MCP, Aβ(25–35) and their combinations at 24 h and 48 h time points. In this study, pretreatment of curcumin to the SH-SY5Y cells enhanced the expression of DNA repair enzymes APE1, pol β, and PARP1 enzymes to counter the oxidative DNA base damage via base excision repair (BER) pathway, and also activated the antioxidant element (ARE) via Nrf2 upregulation. Furthermore, the immunofluorescent confocal imaging studies in SH-SY5Y and IMR-32 cells treated with Aβ(25–35) and MCP-mediated oxidative stress and their combinations at different time periods suggesting for cross-talk between the two proteins APE1 and Nrf2. The APE1’s association with Nrf2 might be associated with the redox function of APE1 that might be directly regulating the ARE-mediated neuronal survival mechanisms.
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    Biosensors for breast cancer diagnosis: A review of bioreceptors, biotransducers and signal amplification strategies
    (Elsevier Ltd, 2017) Mittal, Sunil; Kaur, Hardeep; Gautam, Nandini; Mantha, Anil K.
    Breast cancer is highly prevalent in females and accounts for second highest number of deaths, worldwide. Cumbersome, expensive and time consuming detection techniques presently available for detection of breast cancer potentiates the need for development of novel, specific and ultrasensitive devices. Biosensors are the promising and selective detection devices which hold immense potential as point of care (POC) tools. Present review comprehensively scrutinizes various breast cancer biosensors developed so far and their technical evaluation with respect to efficiency and potency of selected bioreceptors and biotransducers. Use of glycoproteins, DNA biomarkers, micro-RNA, circulatory tumor cells (CTC) and some potential biomarkers are introduced briefly. The review also discusses various strategies used in signal amplification such as nanomaterials, redox mediators, p19 protein, duplex specific nucleases (DSN) and redox cycling. ? 2016 Elsevier B.V.
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    APE1/Ref-1 as an emerging therapeutic target for various human diseases: Phytochemical modulation of its functions
    (Nature Publishing Group, 2014) Thakur, Shweta; Sarkar, Bibekananda; Cholia, Ravi P.; Gautam, Nandini; Dhiman, Monisha; Mantha, Anil K.
    Apurinic/apyrimidinic endonuclease 1 (APE1) is a multifunctional enzyme involved in the base excision repair (BER) pathway, which repairs oxidative base damage caused by endogenous and exogenous agents. APE1 acts as a reductive activator of many transcription factors (TFs) and has also been named redox effector factor 1, Ref-1. For example, APE1 activates activator protein-1, nuclear factor kappa B, hypoxia-inducible factor 1a, paired box gene 8, signal transducer activator of transcription 3 and p53, which are involved in apoptosis, inflammation, angiogenesis and survival pathways. APE1/Ref-1 maintains cellular homeostasis (redox) via the activation of TFs that regulate various physiological processes and that crosstalk with redox balancing agents (for example, thioredoxin, catalase and superoxide dismutase) by controlling levels of reactive oxygen and nitrogen species. The efficiency of APE1/Ref-1's function(s) depends on pairwise interaction with participant protein(s), the functions regulated by APE1/Ref-1 include the BER pathway, TFs, energy metabolism, cytoskeletal elements and stress-dependent responses. Thus, APE1/Ref-1 acts as a 'hub-protein' that controls pathways that are important for cell survival. In this review, we will discuss APE1/Ref-1's versatile nature in various human etiologies, including neurodegeneration, cancer, cardiovascular and other diseases that have been linked with alterations in the expression, subcellular localization and activities of APE/Ref-1. APE1/Ref-1 can be targeted for therapeutic intervention using natural plant products that modulate the expression and functions of APE1/Ref-1. In addition, studies focusing on translational applications based on APE1/Ref-1-mediated therapeutic interventions are discussed. ? 2014 KSBMB.