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20 results on '"Abate, Wondwossen"'

10. Fast, Ultrasensitive Detection of Reactive Oxygen Species Using a Carbon Nanotube Based-Electrocatalytic Intracellular Sensor

Author

Rawson, Frankie J., primary, Hicks, Jacqueline, additional, Dodd, Nicholas, additional, Abate, Wondwossen, additional, Garrett, David J., additional, Yip, Nga, additional, Fejer, Gyorgy, additional, Downard, Alison J., additional, Baronian, Kim H. R., additional, Jackson, Simon K., additional, and Mendes, Paula M., additional

Published
2015
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14. Three-dimensional spheroid cultures of A549 and HepG2 cells exhibit different lipopolysaccharide (LPS) receptor expression and LPS-induced cytokine response compared with monolayer cultures.

Author

Jian Liu, Abate, Wondwossen, Jinsheng Xu, Corry, David, Kaul, Baksho, and Jackson, Simon K.

Subjects
*LIVER cells, *ENDOTOXINS, *CELL receptors, *CELL culture, *CYTOKINES, *INFLAMMATION, *ACTIN, *INTERLEUKIN-6
Abstract

Lipopolysaccharide (LPS) is a potent modulator of pathogen-induced host inflammatory responses. Lipopolysaccharide signaling to host cells is correlated with the expression of well-characterized LPS receptors. We have developed three-dimensional (3-D) cell cultures (spheroids) that are more representative of in vivo conditions than traditional monolayer cultures and may provide novel in vitro models to study the inflammatory response. In this work, we have compared F-actin organization, LPS-induced pro-inflammatory cytokine response and LPS receptor expression between spheroid and monolayer cultures from A549 lung epithelial cells and HepG2 hepatocytes. Significant junctional F-actin was seen at the cell—cell contact points throughout the spheroids, while monolayer cells showed stress fibers of actin and more prominent F-actin localized at the cell base. A time course of cytokine release in response to LPS showed that A549 spheroids secreted persistently higher levels of interleukin (IL)-6 and IL-8 compared with monolayer cultures. Unlike monolayer cultures, HepG2 spheroids responded to LPS by releasing a significant level of IL-8. We identified a significant increase in the expression of CD14 and MD2 in these spheroids compared with monolayers, which may explain the enhanced cytokine response to LPS. Thus, we suggest that 3-D spheroid cell cultures are more typical of in vivo cell responses to LPS during the development of inflammation and would be a better in vitro model in inflammation studies. [ABSTRACT FROM AUTHOR]

Published
2011
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15. Evaluation of inflammatory effects of airborne endotoxin emitted from composting sources.

Author

Jian Liu, Pankhurst, Louise J., Deacon, Lewis J., Abate, Wondwossen, Hayes, Enda T., Drew, Gill H., Longhurst, Phil J., Pollard, Simon, Longhurst, James, Tyrrel, Sean F., and Jackson, Simon K.

Subjects
IMMUNOLOGY of inflammation, ENDOTOXIN analysis, COMPOSTING, INTERLEUKIN-8, CYTOKINES, AEROSOLS & the environment, EPITHELIAL cells, BACTERIAL genetics, ESCHERICHIA coli
Abstract

Because of the lack of effective methodology, the biological effects of environmental endotoxin have not been assessed. Here we have collected and measured airborne endotoxin at different locations around composting sites. Increased endotoxin concentrations were observed close to composting activities and also at nearby boundary areas. Analysis of proinflammatory effects of the environmental endotoxin on interleukin (IL)-8 and IL-6 release from human D562 pharyngeal epithelial and MM6 monocytic cell cultures showed an association between endotoxin level and cytokine induction. The cytokine-inducing effect of bioaerosol extracts was inhibited by polymyxin B, indicating that endotoxin was the cause of cytokine responses we found. The environmental endotoxin was also more active for stimulating cytokines in airway epithelial cells than commercially purified Escherichia coli endotoxin. Our results suggest that these in vitro inflammatory cell models may contribute to the assessment of health impacts of environmental endotoxin. Environ. Toxicol. Chem. 2011; 30:602-606. © 2011 SETAC [ABSTRACT FROM AUTHOR]

Published
2011
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16. Three-dimensional spheroid cultures of A549 and HepG2 cells exhibit different lipopolysaccharide (LPS) receptor expression and LPS-induced cytokine response compared with monolayer cultures

Author

Liu, Jian, Abate, Wondwossen, Xu, Jinsheng, Corry, David, Kaul, Baksho, and Jackson, Simon

Abstract

Lipopolysaccharide (LPS) is a potent modulator of pathogen-induced host inflammatory responses. Lipopolysaccharide signaling to host cells is correlated with the expression of well-characterized LPS receptors. We have developed three-dimensional (3-D) cell cultures (spheroids) that are more representative of in vivo conditions than traditional monolayer cultures and may provide novel in vitro models to study the inflammatory response. In this work, we have compared F-actin organization, LPS-induced pro-inflammatory cytokine response and LPS receptor expression between spheroid and monolayer cultures from A549 lung epithelial cells and HepG2 hepatocytes. Significant junctional F-actin was seen at the cell—cell contact points throughout the spheroids, while monolayer cells showed stress fibers of actin and more prominent F-actin localized at the cell base. A time course of cytokine release in response to LPS showed that A549 spheroids secreted persistently higher levels of interleukin (IL)-6 and IL-8 compared with monolayer cultures. Unlike monolayer cultures, HepG2 spheroids responded to LPS by releasing a significant level of IL-8. We identified a significant increase in the expression of CD14 and MD2 in these spheroids compared with monolayers, which may explain the enhanced cytokine response to LPS. Thus, we suggest that 3-D spheroid cell cultures are more typical of in vivo cell responses to LPS during the development of inflammation and would be a better in vitro model in inflammation studies.

Published
2011
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17. Fast, ultrasensitive detection of reactive oxygen species using a carbon nanotube based-electrocatalytic intracellular sensor

Author

Rawson, Frankie J., Hicks, Jacqueline, Dodd, Nicholas, Abate, Wondwossen, Garrett, David J., Yip, Nga-Chi, Fejer, Gyorgy, Downard, Alison J., Baronian, Kim H.R., Jackson, Simon K., Mendes, Paula M., Rawson, Frankie J., Hicks, Jacqueline, Dodd, Nicholas, Abate, Wondwossen, Garrett, David J., Yip, Nga-Chi, Fejer, Gyorgy, Downard, Alison J., Baronian, Kim H.R., Jackson, Simon K., and Mendes, Paula M.

Abstract

Herein, we report a highly sensitive electrocatalytic sensor-cell construct that can electrochemically communicate with the internal environment of immune cells (e.g., macrophages) via the selective monitoring of a particular reactive oxygen species (ROS), hydrogen peroxide. The sensor, which is based on vertically aligned single-walled carbon nanotubes functionalized with an osmium electrocatalyst, enabled the unprecedented detection of a local intracellular “pulse” of ROS on a short second time scale in response to bacterial endotoxin (lipopolysaccharide-LPS) stimulation. Our studies have shown that this initial pulse of ROS is dependent on NADPH oxidase (NOX) and toll like receptor 4 (TLR4). The results suggest that bacteria can induce a rapid intracellular pulse of ROS in macrophages that initiates the classical innate immune response of these cells to infection.

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18. Fast, ultrasensitive detection of reactive oxygen species using a carbon nanotube based-electrocatalytic intracellular sensor

Author

Rawson, Frankie J., Hicks, Jacqueline, Dodd, Nicholas, Abate, Wondwossen, Garrett, David J., Yip, Nga-Chi, Fejer, Gyorgy, Downard, Alison J., Baronian, Kim H.R., Jackson, Simon K., Mendes, Paula M., Rawson, Frankie J., Hicks, Jacqueline, Dodd, Nicholas, Abate, Wondwossen, Garrett, David J., Yip, Nga-Chi, Fejer, Gyorgy, Downard, Alison J., Baronian, Kim H.R., Jackson, Simon K., and Mendes, Paula M.

Abstract

Herein, we report a highly sensitive electrocatalytic sensor-cell construct that can electrochemically communicate with the internal environment of immune cells (e.g., macrophages) via the selective monitoring of a particular reactive oxygen species (ROS), hydrogen peroxide. The sensor, which is based on vertically aligned single-walled carbon nanotubes functionalized with an osmium electrocatalyst, enabled the unprecedented detection of a local intracellular “pulse” of ROS on a short second time scale in response to bacterial endotoxin (lipopolysaccharide-LPS) stimulation. Our studies have shown that this initial pulse of ROS is dependent on NADPH oxidase (NOX) and toll like receptor 4 (TLR4). The results suggest that bacteria can induce a rapid intracellular pulse of ROS in macrophages that initiates the classical innate immune response of these cells to infection.

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19. Fast, ultrasensitive detection of reactive oxygen species using a carbon nanotube based-electrocatalytic intracellular sensor

Author

Rawson, Frankie J., Hicks, Jacqueline, Dodd, Nicholas, Abate, Wondwossen, Garrett, David J., Yip, Nga-Chi, Fejer, Gyorgy, Downard, Alison J., Baronian, Kim H.R., Jackson, Simon K., Mendes, Paula M., Rawson, Frankie J., Hicks, Jacqueline, Dodd, Nicholas, Abate, Wondwossen, Garrett, David J., Yip, Nga-Chi, Fejer, Gyorgy, Downard, Alison J., Baronian, Kim H.R., Jackson, Simon K., and Mendes, Paula M.

Abstract

Herein, we report a highly sensitive electrocatalytic sensor-cell construct that can electrochemically communicate with the internal environment of immune cells (e.g., macrophages) via the selective monitoring of a particular reactive oxygen species (ROS), hydrogen peroxide. The sensor, which is based on vertically aligned single-walled carbon nanotubes functionalized with an osmium electrocatalyst, enabled the unprecedented detection of a local intracellular “pulse” of ROS on a short second time scale in response to bacterial endotoxin (lipopolysaccharide-LPS) stimulation. Our studies have shown that this initial pulse of ROS is dependent on NADPH oxidase (NOX) and toll like receptor 4 (TLR4). The results suggest that bacteria can induce a rapid intracellular pulse of ROS in macrophages that initiates the classical innate immune response of these cells to infection.

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20. Fast, ultrasensitive detection of reactive oxygen species using a carbon nanotube based-electrocatalytic intracellular sensor

Author

Rawson, Frankie J., Hicks, Jacqueline, Dodd, Nicholas, Abate, Wondwossen, Garrett, David J., Yip, Nga-Chi, Fejer, Gyorgy, Downard, Alison J., Baronian, Kim H.R., Jackson, Simon K., Mendes, Paula M., Rawson, Frankie J., Hicks, Jacqueline, Dodd, Nicholas, Abate, Wondwossen, Garrett, David J., Yip, Nga-Chi, Fejer, Gyorgy, Downard, Alison J., Baronian, Kim H.R., Jackson, Simon K., and Mendes, Paula M.

Abstract

Herein, we report a highly sensitive electrocatalytic sensor-cell construct that can electrochemically communicate with the internal environment of immune cells (e.g., macrophages) via the selective monitoring of a particular reactive oxygen species (ROS), hydrogen peroxide. The sensor, which is based on vertically aligned single-walled carbon nanotubes functionalized with an osmium electrocatalyst, enabled the unprecedented detection of a local intracellular “pulse” of ROS on a short second time scale in response to bacterial endotoxin (lipopolysaccharide-LPS) stimulation. Our studies have shown that this initial pulse of ROS is dependent on NADPH oxidase (NOX) and toll like receptor 4 (TLR4). The results suggest that bacteria can induce a rapid intracellular pulse of ROS in macrophages that initiates the classical innate immune response of these cells to infection.

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