Biochemistry And Microbial Sciences - Research Publications

Permanent URI for this collectionhttps://kr.cup.edu.in/handle/32116/27

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Author: search.filters.author.Mantha, Anil K.

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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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    Phytochemical Ginkgolide B Attenuates Amyloid-? amage and Altered Cellular Responses in Human Neuroblastoma SH-SY5Y Cells
    (IOS Press, 2017) Gill I.; Kaur S.; Kaur N.; Dhiman, Monisha; Mantha, Anil K.
    Oxidative stress is an upsurge in reactive oxygen/nitrogen species (ROS/RNS), which aggravates damage to cellular components viz. lipids, proteins, and nucleic acids resulting in impaired cellular functions and neurological pathologies including Alzheimer's disease (AD). In the present study, we have examined amyloid-? (A?)-induced oxidative stress responses, a major cause for AD, in the undifferentiated and differentiated human neuroblastoma SH-SY5Y cells. A?1-42-induced oxidative damage was evaluated on lipids by lipid peroxidation; proteins by protein carbonyls; antioxidant status by SOD and GSH enzyme activities; and DNA and RNA damage levels by evaluating the number of AP sites and 8-OHG base damages produced. In addition, the neuro-protective role of the phytochemical ginkgolide B (GB) in countering A?1-42-induced oxidative stress was assessed. We report that the differentiated cells are highly vulnerable to A?1-42-induced oxidative stress events as exerted by the deposition of A? in AD. Results of the current study suggest that the pre-treatment of GB, followed by A?1-42 treatment for 24, displayed neuro-protective potential, which countered A?1-42-induced oxidative stress responses in both undifferentiated and differentiated SH-SY5Y neuronal cells by: 1) hampering production of ROS and RNS; 2) reducing lipid peroxidation; 3) decreasing protein carbonyl content; 4) restoring antioxidant activities of SOD and GSH enzymes; and 5) maintaining genome integrity by reducing the oxidative DNA and RNA base damages. In conclusion, A?1-42 induces oxidative damage to the cellular biomolecules, which are associated with AD pathology, and are protected by the pre-treatment of GB against A?-toxicity. Taken together, this study advocates for phytochemical-based therapeutic interventions against AD.
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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