Microbiology - Research Publications

Permanent URI for this collectionhttps://kr.cup.edu.in/handle/32116/51

Browse

Author: search.filters.author.Gupta, Kunj Bihari

Search Results

Now showing 1 - 6 of 6
  • No Thumbnail Available
    Item
    Gliadin induced oxidative stress and altered cellular responses in human intestinal cells: An in-vitro study to understand the cross-talk between the transcription factor Nrf-2 and multifunctional APE1 enzyme
    (John Wiley and Sons Inc, 2022-05-09T00:00:00) Gupta, Kunj Bihari; Dhiman, Monisha; Mantha, Anil Kumar
    The present study examined the wheat protein gliadin-induced oxidative and nitrosative stress and its downstream responses in human intestinal HCT-116 and HT-29 cells. The beneficial role of dietary phytochemical curcumin and role of multifunctional enzyme Apurinic/aprymidinic endonuclease 1 (APE1) a major player involved in the base excision repair (BER)-pathway in gliadin intolerant intestinal HCT-116 and HT-29 cell lines were evaluated as an in vitro model study. The cultured cells were exposed to gliadin protein, H2O2, and curcumin followed by the assessment of oxidative stress and the consequences were measured using spectrophotometric, PCR, flow cytometer, Western blotting, confocal microscopy, and other methods. Results demonstrate that a 3 h pretreatment of curcumin, followed by the treatment of gliadin protein for 24 h time period protected both the HCT-116 and HT-29 cells via: (i) decreasing the ROS/RNS, restoring the mitochondrial transmembrane potential; (ii) re-establishing the cellular antioxidant defense system (superoxide dismutase, catalase, and GSH); (iii) enhancing the functions of APE1 viz. endonuclease activity and redox activation of transcription factor Nrf-2, the later binds with the antioxidant response elements (ARE) and activates downstream targets involved in cell survival. The cross-talk between APE1 and Nrf-2 was also established using immunofluorescence imaging and co-immunoprecipitation assays. In conclusion, gliadin protein induces oxidative/nitrosative stress, mitochondrial dysfunction and it damages cellular biomolecules in the intestinal cells. Hence it can be attributed to the tissue damage and disease pathogenesis in wheat intolerance-associated intestinal diseases. The gliadin-induced stress and its consequences are significantly reduced by the pretreatment of curcumin via BER-pathway and ARE-pathway; which is evident through the interaction between these two essential proteins. Hence suggesting for the intervention of curcumin and other natural dietary phytochemicals-based disease management and treatment of gliadin intolerance associated intestinal diseases like celiac disease. � 2022 Wiley Periodicals LLC.
  • No Thumbnail Available
    Item
    Methods to Assess Oxidative DNA Base Damage Repair of Apurinic/Apyrimidinic (AP) Sites Using Radioactive and Nonradioactive Oligonucleotide-Based Assays
    (NLM (Medline), 2022-01-19T00:00:00) Gupta, Kunj Bihari; Kaur, Sharanjot; Dhiman, Monisha; Mantha, Anil Kumar
    Reactive oxygen species (ROS) overproduction results in oxidative stress leading to genomic instability via the generation of small base lesions in the genome, and this unrepaired DNA base damage leads to various cellular consequences. The oxidative stress-mediated DNA base damage is involved in various human disorders like cancer, cardiovascular, ocular, and neurodegenerative diseases. Base excision repair (BER) pathway, one of the DNA repair pathways, is majorly involved in the repair of oxidative DNA base lesions, which utilizes a different set of enzymes, including endonuclease viz Apurinic/apyrimidinic endonuclease 1 (APE1). APE1 is a well-known multifunctional enzyme with DNA repair, REDOX regulatory, and protein-protein interaction/cross-talk functions associated with the cell survival mechanisms. APE1 acts as an important player in both normal and cancerous cell survival; thus, evaluating its endonuclease activity in the biological samples provide useful readout of the DNA repair capacity/ability, which can be used to tune for the development of therapeutic candidates via either stimulating or blocking its DNA repair function in normal vs. cancer cells, respectively. This chapter enlists two methods used for the determination of APE1's endonuclease activity by oligonucleotide-based radioactive P32-labeled and nonradioactive fluorescence dyes using the cell extracts and recombinant APE1 protein. � 2022. Springer Science+Business Media, LLC, part of Springer Nature.
  • No Thumbnail Available
    Item
    New pentacyclic triterpene from Potentilla atrosanguinea Lodd. as anticancer agent for breast cancer targeting estrogen receptor-?
    (Taylor and Francis Ltd., 2021-10-04T00:00:00) Kumar, Amit; Gupta, Kunj Bihari; Dhiman, Monisha; Arora, Saroj; Jaitak, Vikas
    One new (compound 3) along with two previously known ursane type triterpenoids (compounds 1 and 2) were purified by chromatographic techniques from ethyl acetate extract of aerial parts of Potentilla atrosanguniea and characterized by HRMS, 1 D and 2 D-NMR. Compounds 1 (ursolic acid), 2 (euscaphic acid) and 3 (3?,20?-dihydroxy 2-oxo-urs-12-en-28-oic acid) were tested for their antiproliferative activity along with standard bazedoxifene. Compounds 1 and 3 were found to be of higher activity (3.71 and 6.05 ?g/mL) as compared to compound 2 and bazedoxifene (IC50: 24.53 and 17.87 ?g/mL). Anti-estrogenic activity of three compounds on breast cancer (BC) were studied in vitro by accessing their antiproliferative activity and binding with estrogen receptor alpha (ER-?). All three compounds have effective binding affinity towards ER-? and decreased cell growth by downregulating the expression of mRNA and its translational protein as tested by semi-qRT-PCR and western blotting. In terms of effectiveness compounds 1 and 3 were found more active due to their antiproliferative, and antiestrogenic activity as compared to standard bazedoxifene. � 2021 Informa UK Limited, trading as Taylor & Francis Group.
  • No Thumbnail Available
    Item
    Gliadin induced oxidative stress and altered cellular responses in human intestinal cells: An in-vitro study to understand the cross-talk between the transcription factor Nrf-2 and multifunctional APE1 enzyme
    (John Wiley and Sons Inc, 2022-05-09T00:00:00) Gupta, Kunj Bihari; Dhiman, Monisha; Mantha, Anil Kumar
    The present study examined the wheat protein gliadin-induced oxidative and nitrosative stress and its downstream responses in human intestinal HCT-116 and HT-29 cells. The beneficial role of dietary phytochemical curcumin and role of multifunctional enzyme Apurinic/aprymidinic endonuclease 1 (APE1) a major player involved in the base excision repair (BER)-pathway in gliadin intolerant intestinal HCT-116 and HT-29 cell lines were evaluated as an in vitro model study. The cultured cells were exposed to gliadin protein, H2O2, and curcumin followed by the assessment of oxidative stress and the consequences were measured using spectrophotometric, PCR, flow cytometer, Western blotting, confocal microscopy, and other methods. Results demonstrate that a 3 h pretreatment of curcumin, followed by the treatment of gliadin protein for 24 h time period protected both the HCT-116 and HT-29 cells via: (i) decreasing the ROS/RNS, restoring the mitochondrial transmembrane potential; (ii) re-establishing the cellular antioxidant defense system (superoxide dismutase, catalase, and GSH); (iii) enhancing the functions of APE1 viz. endonuclease activity and redox activation of transcription factor Nrf-2, the later binds with the antioxidant response elements (ARE) and activates downstream targets involved in cell survival. The cross-talk between APE1 and Nrf-2 was also established using immunofluorescence imaging and co-immunoprecipitation assays. In conclusion, gliadin protein induces oxidative/nitrosative stress, mitochondrial dysfunction and it damages cellular biomolecules in the intestinal cells. Hence it can be attributed to the tissue damage and disease pathogenesis in wheat intolerance-associated intestinal diseases. The gliadin-induced stress and its consequences are significantly reduced by the pretreatment of curcumin via BER-pathway and ARE-pathway; which is evident through the interaction between these two essential proteins. Hence suggesting for the intervention of curcumin and other natural dietary phytochemicals-based disease management and treatment of gliadin intolerance associated intestinal diseases like celiac disease. � 2022 Wiley Periodicals LLC.
  • No Thumbnail Available
    Item
    Methods to Assess Oxidative DNA Base Damage Repair of Apurinic/Apyrimidinic (AP) Sites Using Radioactive and Nonradioactive Oligonucleotide-Based Assays
    (NLM (Medline), 2022-01-19T00:00:00) Gupta, Kunj Bihari; Kaur, Sharanjot; Dhiman, Monisha; Mantha, Anil Kumar
    Reactive oxygen species (ROS) overproduction results in oxidative stress leading to genomic instability via the generation of small base lesions in the genome, and this unrepaired DNA base damage leads to various cellular consequences. The oxidative stress-mediated DNA base damage is involved in various human disorders like cancer, cardiovascular, ocular, and neurodegenerative diseases. Base excision repair (BER) pathway, one of the DNA repair pathways, is majorly involved in the repair of oxidative DNA base lesions, which utilizes a different set of enzymes, including endonuclease viz Apurinic/apyrimidinic endonuclease 1 (APE1). APE1 is a well-known multifunctional enzyme with DNA repair, REDOX regulatory, and protein-protein interaction/cross-talk functions associated with the cell survival mechanisms. APE1 acts as an important player in both normal and cancerous cell survival; thus, evaluating its endonuclease activity in the biological samples provide useful readout of the DNA repair capacity/ability, which can be used to tune for the development of therapeutic candidates via either stimulating or blocking its DNA repair function in normal vs. cancer cells, respectively. This chapter enlists two methods used for the determination of APE1's endonuclease activity by oligonucleotide-based radioactive P32-labeled and nonradioactive fluorescence dyes using the cell extracts and recombinant APE1 protein. � 2022. Springer Science+Business Media, LLC, part of Springer Nature.
  • No Thumbnail Available
    Item
    New pentacyclic triterpene from Potentilla atrosanguinea Lodd. as anticancer agent for breast cancer targeting estrogen receptor-?
    (Taylor and Francis Ltd., 2021-10-04T00:00:00) Kumar, Amit; Gupta, Kunj Bihari; Dhiman, Monisha; Arora, Saroj; Jaitak, Vikas
    One new (compound 3) along with two previously known ursane type triterpenoids (compounds 1 and 2) were purified by chromatographic techniques from ethyl acetate extract of aerial parts of Potentilla atrosanguniea and characterized by HRMS, 1 D and 2 D-NMR. Compounds 1 (ursolic acid), 2 (euscaphic acid) and 3 (3?,20?-dihydroxy 2-oxo-urs-12-en-28-oic acid) were tested for their antiproliferative activity along with standard bazedoxifene. Compounds 1 and 3 were found to be of higher activity (3.71 and 6.05 ?g/mL) as compared to compound 2 and bazedoxifene (IC50: 24.53 and 17.87 ?g/mL). Anti-estrogenic activity of three compounds on breast cancer (BC) were studied in vitro by accessing their antiproliferative activity and binding with estrogen receptor alpha (ER-?). All three compounds have effective binding affinity towards ER-? and decreased cell growth by downregulating the expression of mRNA and its translational protein as tested by semi-qRT-PCR and western blotting. In terms of effectiveness compounds 1 and 3 were found more active due to their antiproliferative, and antiestrogenic activity as compared to standard bazedoxifene. � 2021 Informa UK Limited, trading as Taylor & Francis Group.