The Experts below are selected from a list of 1311 Experts worldwide ranked by ideXlab platform
Satya Narayan - One of the best experts on this subject based on the ideXlab platform.
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adenomatous polyposis coli mediated accumulation of abasic dna lesions lead to Cigarette Smoke Condensate induced neoplastic transformation of normal breast epithelial cells
Neoplasia, 2013Co-Authors: Aruna S. Jaiswal, Harekrushna Panda, Christine Pampo, Dietmar W Siemann, Gary C Gairola, Robert Hromas, Satya NarayanAbstract:Adenomatous polyposis coli (APC) is a multifunctional protein having diverse cellular functions including cell migration, cell-cell adhesion, cell cycle control, chromosomal segregation, and apoptosis. Recently, we found a new role of APC in base excision repair (BER) and showed that it interacts with DNA polymerase β and 5′-flap endonuclease 1 and interferes in BER. Previously, we have also reported that Cigarette Smoke Condensate (CSC) increases expression of APC and enhances the growth of normal human breast epithelial (MCF10A) cells in vitro. In the present study, using APC overexpression and knockdown systems, we have examined the molecular mechanisms by which CSC and its major component, Benzo[α]pyrene, enhances APC-mediated accumulation of abasic DNA lesions, which is cytotoxic and mutagenic in nature, leading to enhanced neoplastic transformation of MCF10A cells in an orthotopic xenograft model.
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9 bromonoscapine induced mitotic arrest of Cigarette Smoke Condensate transformed breast epithelial cells
Journal of Cellular Biochemistry, 2009Co-Authors: Aruna S. Jaiswal, Ritu Aneja, Shahnjayla K Connors, Harish C Joshi, Asha S Multani, Sen Pathak, Satya NarayanAbstract:In the present investigation, we determined the chemotherapeutic efficacy of 9-bromonoscapine (Br-Nos), a more potent noscapine analog, on MCF10A, spontaneously immortalized human normal breast epithelial cells and MCF10A-CSC3, Cigarette Smoke Condensate (CSC)-transformed cells. The results from cytogenetic analysis showed that Br-Nos induced polyploidy and telomeric association in MCF10A-CSC3 cells, while MCF10A cells remained unaffected. Our immunofluorescence data further demonstrated that MCF10A-CSC3 cells were susceptible to mitotic catastrophe on exposure to Br-Nos and failed to recover after drug withdrawal. MCF10A-CSC3 cells exhibited Br-Nos-induced aberrant multipolar spindle formation, which irreversibly impaired the alignment of replicated chromosome to the equatorial plane and finally culminated in cell death. Although MCF10A cells upon Br-Nos treatment showed bipolar spindles with some uncongressed chromosomes, these cells recovered fairly well after drug withdrawal. Our flow-cytometry analysis data reconfirmed that MCF10A-CSC3 cells were more susceptible to cell death compared to MCF10A cells. Furthermore, our results suggest that decreased levels of cdc2/cyclin B1 and cdc2 kinase activity are responsible for Br-Nos-induced mitotic cell arrest leading to cell death in MCF10A-CSC3 cells. This study thus explores the underlying mechanism of Br-Nos-induced mitotic catastrophe in CSC-transformed MCF10A-CSC3 cells and its potential usefulness as a chemotherapeutic agent for prevention of Cigarette Smoke-induced breast cancer growth.
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c ebpβ mediated transcriptional regulation of bcl xl gene expression in human breast epithelial cells in response to Cigarette Smoke Condensate
Oncogene, 2009Co-Authors: Shahnjayla K Connors, Chanakya Nath Kundu, Ramesh Balusu, Aruna S. Jaiswal, C G Gairola, Satya NarayanAbstract:In earlier studies, we have shown that Cigarette Smoke Condensate (CSC), a surrogate for Cigarette Smoke, is capable of transforming the spontaneously immortalized human breast epithelial cell line, MCF10A. These transformed cells displayed upregulation of the anti-apoptotic gene, bcl-xl. Upregulation of this gene may impede the apoptotic pathway and allow the accumulation of DNA damage that can lead to cell transformation and carcinogenesis. In the present study, we have determined the mechanism of CSC-mediated transcriptional upregulation of bcl-xl gene expression in MCF10A cells. We cloned the human bcl-xl promoter (pBcl-xLP) and identified putative transcription factor binding sites. Sequential deletion constructs that removed the putative cis-elements were constructed and transfected into MCF10A cells to determine the CSC-responsive cis-element(s) on the pBcl-xLP. Gel-shift, super-shift and chromatin immunoprecipitation analysis confirmed that CCAAT/enhancer-binding protein (C/EBPβ) specifically bound to a C/EBP-binding site on the pBcl-xLP in vitro and in vivo. Additionally, overexpression of C/EBPβ-LAP2 stimulated pBcl-xLP activity and Bcl-xL protein levels, which mimicked the conditions of CSC treatment. Our results indicate that C/EBPβ regulates bcl-xl gene expression in MCF10A cells in response to CSC treatment; therefore, making it a potential target for chemotherapeutic intervention of Cigarette Smoke-induced breast carcinogenesis.
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Cigarette Smoke Condensate-induced level of adenomatous polyposis coli blocks long-patch base excision repair in breast epithelial cells.
Oncogene, 2006Co-Authors: Chanakya Nath Kundu, Ramesh Balusu, Aruna S. Jaiswal, C G Gairola, Satya NarayanAbstract:Cigarette Smoke Condensate-induced level of adenomatous polyposis coli blocks long-patch base excision repair in breast epithelial cells
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Cigarette Smoke Condensate-induced transformation of normal human breast epithelial cells in vitro
Oncogene, 2004Co-Authors: Satya Narayan, Aruna S. Jaiswal, Diana Kang, Pratima Srivastava, Gokul M Das, C. Gary GairolaAbstract:In the present study, we showed that a single-dose treatment of normal breast epithelial cell line, MCF10A, for 72 h with Cigarette Smoke Condensate (CSC) resulted in a transformed phenotype. The anchorage-dependent growth of these cells was decreased due to increased cell cycle arrest in S–G_2/M phase; however, the surviving cells developed resistance due to an increased Bcl-xL to Bax ratio. Levels of PCNA and gadd45 proteins – involved in DNA repair in response to genomic damage – were increased, suggesting that the cells were responding to CSC-induced genomic damage. The transformation of MCF10A cells was determined by their colony-forming efficiency in soft-agar in an anchorage-independent manner. CSC-treated MCF10A cells efficiently formed colonies in soft-agar. We then re-established cell lines from the soft-agar colonies and further examined the persistence of their transforming characteristics. The re-established cell lines, when plated after 17 passages without CSC treatment, still formed colonies in the soft-agar. An increased staining of neuropilin-1 (NRP-1) further showed a transformation characteristic of MCF10A cells treated with CSC. In summary, our results suggest that CSC is capable of transforming the MCF10A cells in vitro , supporting the role of Cigarette smoking and increased risk for breast cancer.
Kelle H. Moley - One of the best experts on this subject based on the ideXlab platform.
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testicular cells exhibit similar molecular responses to Cigarette Smoke Condensate ex vivo and in vivo
The FASEB Journal, 2018Co-Authors: Prabagaran Esakky, Deborah A. Hansen, Andrea Drury, Paul Felder, Andrew Cusumano, Kelle H. MoleyAbstract:Male exposure to Cigarette Smoke is associated with seminal defects and with congenital anomalies and childhood cancers in offspring. In mice, paternal exposure to Cigarette Smoke Condensate (CSC) causes molecular defects in germ cells and phenotypic effects in their offspring. Here we used an ex vivo testicular explant model and in vivo exposure to determine the concentration at which CSC impairs spermatogenesis and offspring development. We explanted testis tissue at postnatal day (P)5.5 and cultured it until P11.5. Assessment of growth parameters by analyzing expression of cell-specific markers revealed that the explant system maintained structural and functional integrity. We exposed the P5.5 to -11.5 explants to various concentrations (40-160 µg/ml) of CSC and confirmed that nicotine in the CSC was metabolized to cotinine. We assessed various growth and differentiation parameters, as well as testosterone production, and observed that many spermatogenesis features were impaired at 160 µg/ml CSC. The same parameters were impaired by a similar CSC concentration in vivo Finally, females mated to males that were exposed to 160 µg/ml CSC neonatally had increased rates of pup resorption. We conclude that male exposure to CSC impairs offspring development and that the concentration at which CSC impairs spermatogenesis is similar in vivo and ex vivo. Given that the concentrations of CSC we used contained similar doses of nicotine as human Smokers are exposed to, we argue that our model mimics human male reproductive effects of smoking.-Esakky, P., Hansen, D. A., Drury, A. M., Felder, P., Cusumano, A., Moley, K. H. Testicular cells exhibit similar molecular responses to Cigarette Smoke Condensate ex vivo and in vivo.
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Paternal exposure to Cigarette Smoke Condensate leads to reproductive sequelae and developmental abnormalities in the offspring of mice.
Reproductive Toxicology, 2016Co-Authors: Prabagaran Esakky, Deborah A. Hansen, Andrea Drury, Paul Felder, Andrew Cusumano, Kelle H. MoleyAbstract:Paternal smoking is associated with infertility, birth defects and childhood cancers. Our earlier studies using Cigarette Smoke Condensate (CSC) demonstrated several deleterious changes in male germ cells. Here, we hypothesize that chronic paternal exposure to CSC causes molecular and phenotypic changes in the sire and the offspring, respectively. In this mouse study, CSC caused DNA damage and cytotoxicity in testes via accumulation of benzo(a)pyrene (B[a]P) and cotinine. Decreased expression of growth arrest and DNA damage inducible alpha (Gadd45a), aryl hydrocarbon receptor (Ahr), and cyclin-dependent kinase inhibitor 1A (P21) was seen in CSC exposed testes. Apoptotic germ cell death was detected by induction of Fas, FasL, and activated caspase-3. The CSC-exposed males displayed reduction in sperm motility and fertilizing ability and sired pups with reduced body weight and crown-rump length, and smaller litter size with higher numbers of resorption. This model of CSC exposure demonstrates testicular toxicity and developmental defects in the offspring.
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modulation of cell cycle progression in the spermatocyte cell line gc 2spd ts cell line by Cigarette Smoke Condensate csc via arylhydrocarbon receptor nuclear factor erythroid 2 related factor 2 ahr nrf2 pathway
Biology of Reproduction, 2014Co-Authors: Prabagaran Esakky, Deborah A. Hansen, Andrea Drury, Kelle H. MoleyAbstract:Prior studies in our laboratory have demonstrated that Cigarette Smoke Condensate (CSC) activates arylhydrocarbon receptor (Ahr) leading to upregulation of several antioxidant enzymes in murine spermatocytes. In this study, we show that exposure of the spermatocyte cell line GC-2spd(ts) to CSC induces an increase in Cyp1a1, demonstrating AHR activation, and simultaneous expression and nuclear translocation of nuclear factor erythroid 2-related factor 2 (NRF2), where it is believed to modulate Ahr expression by a feedback mechanism. Pharmacological inhibition by the AHR-antagonist CH223191 and interference by Ahr- and Nrf2-small interfering RNA followed by quantitative real-time PCR implicate the Ahr-Nrf2 pathway in the modulation of DNA damage and growth suppression genes such as Gadd45a and P21 and oxidative stress-related genes Cyp1a1, Nrf2, and Ahrr. Flow cytometry accompanied with cell proliferation assay indicate the CSC induces accumulation of spermatocytes at the S-G2/M phase of the cell cycle. Thus, the data obtained suggest that CSC contains several AHR-agonists that are capable of altering the growth pattern of spermatocytes in vitro through the Ahr-Nrf2 signaling mechanism.
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Cigarette Smoke Condensate induces aryl hydrocarbon receptor dependent changes in gene expression in spermatocytes
Reproductive Toxicology, 2012Co-Authors: Prabagaran Esakky, Deborah A. Hansen, Andrea Drury, Kelle H. MoleyAbstract:Cigarette Smoke contains numerous compounds that cause oxidative stress and alter gene expression in many tissues, and Cigarette smoking is correlated with male infertility. To identify mechanisms by which this occurs, we evaluated expression of antioxidant genes in mouse spermatocytes in response to Cigarette Smoke Condensate (CSC). CSC exposure led to oxidative stress and dose-dependent up-regulation of Hsp90aa1, Ahr, Arnt, Sod1, Sod2, and Cyp1a1 expression in a mouse spermatocyte cell line. An antagonist of the aryl hydrocarbon receptor (AHR) abrogated several CSC-mediated changes in mRNA and protein levels. Consistent with these results, spermatocytes isolated by laser-capture microdissection from CSC-treated mice showed increased expression of several antioxidant genes. In vivo exposure to CSC was genotoxic to spermatocytes, resulting in apoptosis and disruptions to the seminiferous tubules. Our in vivo and in vitro data indicate that CSC-mediated damage to murine spermatocytes is AHR-dependent and is mediated by oxidative stress.
Aruna S. Jaiswal - One of the best experts on this subject based on the ideXlab platform.
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adenomatous polyposis coli mediated accumulation of abasic dna lesions lead to Cigarette Smoke Condensate induced neoplastic transformation of normal breast epithelial cells
Neoplasia, 2013Co-Authors: Aruna S. Jaiswal, Harekrushna Panda, Christine Pampo, Dietmar W Siemann, Gary C Gairola, Robert Hromas, Satya NarayanAbstract:Adenomatous polyposis coli (APC) is a multifunctional protein having diverse cellular functions including cell migration, cell-cell adhesion, cell cycle control, chromosomal segregation, and apoptosis. Recently, we found a new role of APC in base excision repair (BER) and showed that it interacts with DNA polymerase β and 5′-flap endonuclease 1 and interferes in BER. Previously, we have also reported that Cigarette Smoke Condensate (CSC) increases expression of APC and enhances the growth of normal human breast epithelial (MCF10A) cells in vitro. In the present study, using APC overexpression and knockdown systems, we have examined the molecular mechanisms by which CSC and its major component, Benzo[α]pyrene, enhances APC-mediated accumulation of abasic DNA lesions, which is cytotoxic and mutagenic in nature, leading to enhanced neoplastic transformation of MCF10A cells in an orthotopic xenograft model.
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9 bromonoscapine induced mitotic arrest of Cigarette Smoke Condensate transformed breast epithelial cells
Journal of Cellular Biochemistry, 2009Co-Authors: Aruna S. Jaiswal, Ritu Aneja, Shahnjayla K Connors, Harish C Joshi, Asha S Multani, Sen Pathak, Satya NarayanAbstract:In the present investigation, we determined the chemotherapeutic efficacy of 9-bromonoscapine (Br-Nos), a more potent noscapine analog, on MCF10A, spontaneously immortalized human normal breast epithelial cells and MCF10A-CSC3, Cigarette Smoke Condensate (CSC)-transformed cells. The results from cytogenetic analysis showed that Br-Nos induced polyploidy and telomeric association in MCF10A-CSC3 cells, while MCF10A cells remained unaffected. Our immunofluorescence data further demonstrated that MCF10A-CSC3 cells were susceptible to mitotic catastrophe on exposure to Br-Nos and failed to recover after drug withdrawal. MCF10A-CSC3 cells exhibited Br-Nos-induced aberrant multipolar spindle formation, which irreversibly impaired the alignment of replicated chromosome to the equatorial plane and finally culminated in cell death. Although MCF10A cells upon Br-Nos treatment showed bipolar spindles with some uncongressed chromosomes, these cells recovered fairly well after drug withdrawal. Our flow-cytometry analysis data reconfirmed that MCF10A-CSC3 cells were more susceptible to cell death compared to MCF10A cells. Furthermore, our results suggest that decreased levels of cdc2/cyclin B1 and cdc2 kinase activity are responsible for Br-Nos-induced mitotic cell arrest leading to cell death in MCF10A-CSC3 cells. This study thus explores the underlying mechanism of Br-Nos-induced mitotic catastrophe in CSC-transformed MCF10A-CSC3 cells and its potential usefulness as a chemotherapeutic agent for prevention of Cigarette Smoke-induced breast cancer growth.
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c ebpβ mediated transcriptional regulation of bcl xl gene expression in human breast epithelial cells in response to Cigarette Smoke Condensate
Oncogene, 2009Co-Authors: Shahnjayla K Connors, Chanakya Nath Kundu, Ramesh Balusu, Aruna S. Jaiswal, C G Gairola, Satya NarayanAbstract:In earlier studies, we have shown that Cigarette Smoke Condensate (CSC), a surrogate for Cigarette Smoke, is capable of transforming the spontaneously immortalized human breast epithelial cell line, MCF10A. These transformed cells displayed upregulation of the anti-apoptotic gene, bcl-xl. Upregulation of this gene may impede the apoptotic pathway and allow the accumulation of DNA damage that can lead to cell transformation and carcinogenesis. In the present study, we have determined the mechanism of CSC-mediated transcriptional upregulation of bcl-xl gene expression in MCF10A cells. We cloned the human bcl-xl promoter (pBcl-xLP) and identified putative transcription factor binding sites. Sequential deletion constructs that removed the putative cis-elements were constructed and transfected into MCF10A cells to determine the CSC-responsive cis-element(s) on the pBcl-xLP. Gel-shift, super-shift and chromatin immunoprecipitation analysis confirmed that CCAAT/enhancer-binding protein (C/EBPβ) specifically bound to a C/EBP-binding site on the pBcl-xLP in vitro and in vivo. Additionally, overexpression of C/EBPβ-LAP2 stimulated pBcl-xLP activity and Bcl-xL protein levels, which mimicked the conditions of CSC treatment. Our results indicate that C/EBPβ regulates bcl-xl gene expression in MCF10A cells in response to CSC treatment; therefore, making it a potential target for chemotherapeutic intervention of Cigarette Smoke-induced breast carcinogenesis.
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Cigarette Smoke Condensate-induced level of adenomatous polyposis coli blocks long-patch base excision repair in breast epithelial cells.
Oncogene, 2006Co-Authors: Chanakya Nath Kundu, Ramesh Balusu, Aruna S. Jaiswal, C G Gairola, Satya NarayanAbstract:Cigarette Smoke Condensate-induced level of adenomatous polyposis coli blocks long-patch base excision repair in breast epithelial cells
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Cigarette Smoke Condensate-induced transformation of normal human breast epithelial cells in vitro
Oncogene, 2004Co-Authors: Satya Narayan, Aruna S. Jaiswal, Diana Kang, Pratima Srivastava, Gokul M Das, C. Gary GairolaAbstract:In the present study, we showed that a single-dose treatment of normal breast epithelial cell line, MCF10A, for 72 h with Cigarette Smoke Condensate (CSC) resulted in a transformed phenotype. The anchorage-dependent growth of these cells was decreased due to increased cell cycle arrest in S–G_2/M phase; however, the surviving cells developed resistance due to an increased Bcl-xL to Bax ratio. Levels of PCNA and gadd45 proteins – involved in DNA repair in response to genomic damage – were increased, suggesting that the cells were responding to CSC-induced genomic damage. The transformation of MCF10A cells was determined by their colony-forming efficiency in soft-agar in an anchorage-independent manner. CSC-treated MCF10A cells efficiently formed colonies in soft-agar. We then re-established cell lines from the soft-agar colonies and further examined the persistence of their transforming characteristics. The re-established cell lines, when plated after 17 passages without CSC treatment, still formed colonies in the soft-agar. An increased staining of neuropilin-1 (NRP-1) further showed a transformation characteristic of MCF10A cells treated with CSC. In summary, our results suggest that CSC is capable of transforming the MCF10A cells in vitro , supporting the role of Cigarette smoking and increased risk for breast cancer.
Prabagaran Esakky - One of the best experts on this subject based on the ideXlab platform.
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testicular cells exhibit similar molecular responses to Cigarette Smoke Condensate ex vivo and in vivo
The FASEB Journal, 2018Co-Authors: Prabagaran Esakky, Deborah A. Hansen, Andrea Drury, Paul Felder, Andrew Cusumano, Kelle H. MoleyAbstract:Male exposure to Cigarette Smoke is associated with seminal defects and with congenital anomalies and childhood cancers in offspring. In mice, paternal exposure to Cigarette Smoke Condensate (CSC) causes molecular defects in germ cells and phenotypic effects in their offspring. Here we used an ex vivo testicular explant model and in vivo exposure to determine the concentration at which CSC impairs spermatogenesis and offspring development. We explanted testis tissue at postnatal day (P)5.5 and cultured it until P11.5. Assessment of growth parameters by analyzing expression of cell-specific markers revealed that the explant system maintained structural and functional integrity. We exposed the P5.5 to -11.5 explants to various concentrations (40-160 µg/ml) of CSC and confirmed that nicotine in the CSC was metabolized to cotinine. We assessed various growth and differentiation parameters, as well as testosterone production, and observed that many spermatogenesis features were impaired at 160 µg/ml CSC. The same parameters were impaired by a similar CSC concentration in vivo Finally, females mated to males that were exposed to 160 µg/ml CSC neonatally had increased rates of pup resorption. We conclude that male exposure to CSC impairs offspring development and that the concentration at which CSC impairs spermatogenesis is similar in vivo and ex vivo. Given that the concentrations of CSC we used contained similar doses of nicotine as human Smokers are exposed to, we argue that our model mimics human male reproductive effects of smoking.-Esakky, P., Hansen, D. A., Drury, A. M., Felder, P., Cusumano, A., Moley, K. H. Testicular cells exhibit similar molecular responses to Cigarette Smoke Condensate ex vivo and in vivo.
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Paternal exposure to Cigarette Smoke Condensate leads to reproductive sequelae and developmental abnormalities in the offspring of mice.
Reproductive Toxicology, 2016Co-Authors: Prabagaran Esakky, Deborah A. Hansen, Andrea Drury, Paul Felder, Andrew Cusumano, Kelle H. MoleyAbstract:Paternal smoking is associated with infertility, birth defects and childhood cancers. Our earlier studies using Cigarette Smoke Condensate (CSC) demonstrated several deleterious changes in male germ cells. Here, we hypothesize that chronic paternal exposure to CSC causes molecular and phenotypic changes in the sire and the offspring, respectively. In this mouse study, CSC caused DNA damage and cytotoxicity in testes via accumulation of benzo(a)pyrene (B[a]P) and cotinine. Decreased expression of growth arrest and DNA damage inducible alpha (Gadd45a), aryl hydrocarbon receptor (Ahr), and cyclin-dependent kinase inhibitor 1A (P21) was seen in CSC exposed testes. Apoptotic germ cell death was detected by induction of Fas, FasL, and activated caspase-3. The CSC-exposed males displayed reduction in sperm motility and fertilizing ability and sired pups with reduced body weight and crown-rump length, and smaller litter size with higher numbers of resorption. This model of CSC exposure demonstrates testicular toxicity and developmental defects in the offspring.
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modulation of cell cycle progression in the spermatocyte cell line gc 2spd ts cell line by Cigarette Smoke Condensate csc via arylhydrocarbon receptor nuclear factor erythroid 2 related factor 2 ahr nrf2 pathway
Biology of Reproduction, 2014Co-Authors: Prabagaran Esakky, Deborah A. Hansen, Andrea Drury, Kelle H. MoleyAbstract:Prior studies in our laboratory have demonstrated that Cigarette Smoke Condensate (CSC) activates arylhydrocarbon receptor (Ahr) leading to upregulation of several antioxidant enzymes in murine spermatocytes. In this study, we show that exposure of the spermatocyte cell line GC-2spd(ts) to CSC induces an increase in Cyp1a1, demonstrating AHR activation, and simultaneous expression and nuclear translocation of nuclear factor erythroid 2-related factor 2 (NRF2), where it is believed to modulate Ahr expression by a feedback mechanism. Pharmacological inhibition by the AHR-antagonist CH223191 and interference by Ahr- and Nrf2-small interfering RNA followed by quantitative real-time PCR implicate the Ahr-Nrf2 pathway in the modulation of DNA damage and growth suppression genes such as Gadd45a and P21 and oxidative stress-related genes Cyp1a1, Nrf2, and Ahrr. Flow cytometry accompanied with cell proliferation assay indicate the CSC induces accumulation of spermatocytes at the S-G2/M phase of the cell cycle. Thus, the data obtained suggest that CSC contains several AHR-agonists that are capable of altering the growth pattern of spermatocytes in vitro through the Ahr-Nrf2 signaling mechanism.
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Cigarette Smoke Condensate induces aryl hydrocarbon receptor dependent changes in gene expression in spermatocytes
Reproductive Toxicology, 2012Co-Authors: Prabagaran Esakky, Deborah A. Hansen, Andrea Drury, Kelle H. MoleyAbstract:Cigarette Smoke contains numerous compounds that cause oxidative stress and alter gene expression in many tissues, and Cigarette smoking is correlated with male infertility. To identify mechanisms by which this occurs, we evaluated expression of antioxidant genes in mouse spermatocytes in response to Cigarette Smoke Condensate (CSC). CSC exposure led to oxidative stress and dose-dependent up-regulation of Hsp90aa1, Ahr, Arnt, Sod1, Sod2, and Cyp1a1 expression in a mouse spermatocyte cell line. An antagonist of the aryl hydrocarbon receptor (AHR) abrogated several CSC-mediated changes in mRNA and protein levels. Consistent with these results, spermatocytes isolated by laser-capture microdissection from CSC-treated mice showed increased expression of several antioxidant genes. In vivo exposure to CSC was genotoxic to spermatocytes, resulting in apoptosis and disruptions to the seminiferous tubules. Our in vivo and in vitro data indicate that CSC-mediated damage to murine spermatocytes is AHR-dependent and is mediated by oxidative stress.
Charles Feldman - One of the best experts on this subject based on the ideXlab platform.
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biofilm formation and induction of stress response genes is a common response of several serotypes of the pneumococcus to Cigarette Smoke Condensate
Journal of Infection, 2020Co-Authors: Riana Cockeran, Helen C. Steel, Caroline Dickens, R Anderson, Therese Dixpeek, Charles FeldmanAbstract:Summary Objectives Exposure to Cigarette Smoke impacts on the virulence of Streptococcus pneumoniae (pneumococcus) by mechanisms including induction of biofilm formation. Most studies, however, have focused on individual strains of the pneumococcus. Accordingly, the current study has investigated the commonality of the pneumococcal stress response to Cigarette Smoke Condensate (CSC), using five different strains of the pathogen. Methods Following exposure to CSC at final concentrations of 80 and 160 µg mL−1 during a 16 h incubation period, biofilm formation was measured using a crystal violet-based spectrophotometric procedure. Expression of stress genes seemingly linked to biofilm formation viz. hk11 and rr11 [histidine kinase and response regulator of the two-component regulatory system 11 (TCS11) respectively], cat eff (cation efflux system protein), abc (ATP-binding component of an ATP-binding cassette transporter) and 2005-hyp (hypothetical gene) was measured by sequential extraction of RNA, cDNA synthesis and real-time qPCR. Results Exposure of all five strains of the pneumococcus to CSC, resulted in significant biofilm formation, as well as induction of all five test stress genes. Conclusions Augmentation of induction of selective stress genes and biofilm formation are common, possibly linked, responses of various serotypes of the pneumococcus to CSC, favouring both persistence of the pathogen and decreased efficacy of antibiotics.
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Research Article Exposure of a 23F Serotype Strain of Streptococcus pneumoniae to Cigarette Smoke Condensate Is Associated with Selective Upregulation of Genes Encoding the Two-Component Regulatory System 11 (TCS11)
2016Co-Authors: Riana Cockeran, Timothy J Mitchell, Ronald Anderson, Jenny A. Herbert, Therese Dix-peek, Caroline Dickens, Charles FeldmanAbstract:Copyright © 2014 Riana Cockeran et al.This is an open access article distributed under theCreative CommonsAttribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Alterations in whole genome expression profiles following exposure of the pneumococcus (strain 172, serotype 23F) to Cigarette Smoke Condensate (16
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Exposure of a 23F Serotype Strain of Streptococcus pneumoniae to Cigarette Smoke Condensate Is Associated with Selective Upregulation of Genes Encoding the Two-Component Regulatory System 11 (TCS11)
BioMed research international, 2014Co-Authors: Riana Cockeran, Timothy J Mitchell, Ronald Anderson, Jenny A. Herbert, Therese Dix-peek, Caroline Dickens, Charles FeldmanAbstract:Alterations in whole genome expression profiles following exposure of the pneumococcus (strain 172, serotype 23F) to Cigarette Smoke Condensate (160 μg/mL) for 15 and 60 min have been determined using the TIGR4 DNA microarray chip. Exposure to CSC resulted in the significant (P < 0.014–0.0006) upregulation of the genes encoding the two-component regulatory system 11 (TCS11), consisting of the sensor kinase, hk11, and its cognate response regulator, rr11, in the setting of increased biofilm formation. These effects of Cigarette Smoke on the pneumococcus may contribute to colonization of the airways by this microbial pathogen.
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Effects of Cigarette Smoke Condensate on pneumococcal biofilm formation and pneumolysin
The European respiratory journal, 2012Co-Authors: N. Daphney Mutepe, Timothy J Mitchell, Charles Feldman, Riana Cockeran, Annette J. Theron, Helen C. Steel, Ronald AndersonAbstract:Although the well-recognised predisposition of Cigarette Smokers to the development of severe pneumococcal disease may be attributable to impairment of local host defences, less is known about the direct effects of Smoke exposure on airway pathogens, or their virulence factors. In the current study, we have investigated the effects of Cigarette Smoke Condensate (CSC) on biofilm formation by Streptococcus pneumoniae , and on the pore-forming activity of its major toxin, pneumolysin. Biofilm formation following exposure of the pneumococcus to CSC (20–160 μg·mL−1) was measured using a crystal violet-based spectrophotometric procedure, while the pore-forming activity of recombinant pneumolysin was determined by a fura-2/acetoxymethyl ester-based spectrofluorimetric procedure to monitor the uptake of extracellular Ca2+ by isolated human neutrophils. Exposure of the pneumococcus or pneumolysin to CSC resulted in significant dose-related augmentation of biofilm formation (p≤0.05 at 80 and 160 μg·mL−1) and substantial attenuation of the pore-forming interactions of pneumolysin, respectively. Augmentation of biofilm formation and inactivation of pneumolysin as a consequence of smoking are likely to favour microbial colonisation and persistence, both being essential precursors of pneumococcal disease.