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Zongliang Chang - One of the best experts on this subject based on the ideXlab platform.

  • Heat-Shock Response down-regulates interleukin-18 expression in murine peritoneal macrophages.
    Biology of the cell, 2005
    Co-Authors: Yun Wang, Zongliang Chang
    Abstract:

    Background information. The Heat-Shock Response is a self-defence mechanism that protects cells and organisms from a wide range of harmful stresses. Recent studies revealed that it involved the regulation of cytokine expression. Interleukin-18 (IL-18) is an important cytokine in mediating immune Response. Results. We studied interferon-gamma (IFN-gamma)-induced IL-18 expression in Heat-Shock-treated murine peritoneal macrophages. Our results showed that the Heat-Shock Response significantly inhibited the expression of IFN-gamma-induced pro-inflammatory cytokine IL-18. Interferon consensus sequence binding protein (ICSBP) is a transcription factor that binds to the promoter of IL-18 and regulates the transcription of IL-18. Further research on the down-regulation mechanism showed that the DNA-binding activity of ICSBP was greatly reduced by the Heat Shock Response. Conclusions. These results suggest that the inhibitory effect of Heat-Shock Response on IL-18 production in IFN-gamma-stimulated macrophages is related to the suppression of the binding activity of ICSBP.

  • Differential regulation of interleukin-12 and interleukin-10 by Heat Shock Response in murine peritoneal macrophages.
    Biochemical and biophysical research communications, 2001
    Co-Authors: Xingyu Wang, Yunyun Zou, Yun Wang, Zongliang Chang
    Abstract:

    Heat Shock Response is a conserved stress Response and has been shown to have anti-inflammatory effects. We investigated the effect of Heat Shock Response on LPS-induced production of IL-12 and IL-10, which are two important cytokines playing contradictory roles in regulation of immune Response, by murine peritoneal macrophages. The data showed that induction of Heat Shock Response strongly suppressed LPS-induced production of IL-12 while augmented that of IL-10, suggesting the pleiotropic effects of Heat Shock Response on immune regulatory gene expression. Also, the novel observation on up-regulation of IL-10 by Heat Shock Response adds to the mechanism by which Heat Shock Response exerts its anti-inflammatory effects.

Yun Wang - One of the best experts on this subject based on the ideXlab platform.

  • Heat-Shock Response down-regulates interleukin-18 expression in murine peritoneal macrophages.
    Biology of the cell, 2005
    Co-Authors: Yun Wang, Zongliang Chang
    Abstract:

    Background information. The Heat-Shock Response is a self-defence mechanism that protects cells and organisms from a wide range of harmful stresses. Recent studies revealed that it involved the regulation of cytokine expression. Interleukin-18 (IL-18) is an important cytokine in mediating immune Response. Results. We studied interferon-gamma (IFN-gamma)-induced IL-18 expression in Heat-Shock-treated murine peritoneal macrophages. Our results showed that the Heat-Shock Response significantly inhibited the expression of IFN-gamma-induced pro-inflammatory cytokine IL-18. Interferon consensus sequence binding protein (ICSBP) is a transcription factor that binds to the promoter of IL-18 and regulates the transcription of IL-18. Further research on the down-regulation mechanism showed that the DNA-binding activity of ICSBP was greatly reduced by the Heat Shock Response. Conclusions. These results suggest that the inhibitory effect of Heat-Shock Response on IL-18 production in IFN-gamma-stimulated macrophages is related to the suppression of the binding activity of ICSBP.

  • Differential regulation of interleukin-12 and interleukin-10 by Heat Shock Response in murine peritoneal macrophages.
    Biochemical and biophysical research communications, 2001
    Co-Authors: Xingyu Wang, Yunyun Zou, Yun Wang, Zongliang Chang
    Abstract:

    Heat Shock Response is a conserved stress Response and has been shown to have anti-inflammatory effects. We investigated the effect of Heat Shock Response on LPS-induced production of IL-12 and IL-10, which are two important cytokines playing contradictory roles in regulation of immune Response, by murine peritoneal macrophages. The data showed that induction of Heat Shock Response strongly suppressed LPS-induced production of IL-12 while augmented that of IL-10, suggesting the pleiotropic effects of Heat Shock Response on immune regulatory gene expression. Also, the novel observation on up-regulation of IL-10 by Heat Shock Response adds to the mechanism by which Heat Shock Response exerts its anti-inflammatory effects.

Robert M. Kelly - One of the best experts on this subject based on the ideXlab platform.

  • Transcriptional analysis of dynamic Heat-Shock Response by the hyperthermophilic bacterium Thermotoga maritima
    Extremophiles, 2004
    Co-Authors: Marybeth A. Pysz, Keith R. Shockley, Donald E. Ward, Shannon B. Conners, Clemente I. Montero, Matthew R. Johnson, Robert M. Kelly
    Abstract:

    The thermal stress Response of the hyperthermophilic bacterium Thermotoga maritima was characterized using a 407-open reading frame-targeted cDNA microarray. Transient gene expression was followed for 90 min, following a shift from 80°C to 90°C. While some aspects of mesophilic Heat-Shock Response were conserved in T. maritima , genome content suggested differentiating features that were borne out by transcriptional analysis. Early induction of predicted Heat-Shock operons hrcA-grpE-dnaJ (TM0851-TM0850-TM0849), groES-groEL (TM0505-TM0506), and dnaK-sHSP (TM0373-TM0374) was consistent with conserved CIRCE elements upstream of hrcA and groES . Induction of the T. maritima rpoE / sigW and rpoD / sigA homologs suggests a mechanism for global Heat-Shock Response in the absence of an identifiable ortholog to a major Heat-Shock sigma factor. In contrast to Heat-Shock Response in Escherichia coli , the majority of genes encoding ATP-dependent proteases were downregulated, including clpP (TM0695), clpQ (TM0521), clpY (TM0522), lonA (TM1633), and lonB (TM1869). Notably, T. maritima showed indications of a late Heat-Shock Response with the induction of a marR homolog (TM0816), several other putative transcriptional regulators (TM1023, TM1069), and two α-glucosidases (TM0434 and TM1068). Taken together, the results reported here indicate that, while T. maritima shares core elements of the bacterial Heat-Shock Response with mesophiles, the thermal stress regulatory strategies of this organism differ significantly. However, it remains to be elucidated whether these differences are related to thermophilicity or phylogenetic placement.

  • Transcriptional analysis of dynamic Heat-Shock Response by the hyperthermophilic bacterium Thermotoga maritima.
    Extremophiles : life under extreme conditions, 2004
    Co-Authors: Marybeth A. Pysz, Keith R. Shockley, Donald E. Ward, Shannon B. Conners, Clemente I. Montero, Matthew R. Johnson, Robert M. Kelly
    Abstract:

    The thermal stress Response of the hyperthermophilic bacterium Thermotoga maritima was characterized using a 407-open reading frame-targeted cDNA microarray. Transient gene expression was followed for 90 min, following a shift from 80°C to 90°C. While some aspects of mesophilic Heat-Shock Response were conserved in T. maritima, genome content suggested differentiating features that were borne out by transcriptional analysis. Early induction of predicted Heat-Shock operons hrcA-grpE-dnaJ (TM0851-TM0850-TM0849), groES-groEL (TM0505-TM0506), and dnaK-sHSP (TM0373-TM0374) was consistent with conserved CIRCE elements upstream of hrcA and groES. Induction of the T. maritima rpoE/sigW and rpoD/sigA homologs suggests a mechanism for global Heat-Shock Response in the absence of an identifiable ortholog to a major Heat-Shock sigma factor. In contrast to Heat-Shock Response in Escherichia coli, the majority of genes encoding ATP-dependent proteases were downregulated, including clpP (TM0695), clpQ (TM0521), clpY (TM0522), lonA (TM1633), and lonB (TM1869). Notably, T. maritima showed indications of a late Heat-Shock Response with the induction of a marR homolog (TM0816), several other putative transcriptional regulators (TM1023, TM1069), and two α-glucosidases (TM0434 and TM1068). Taken together, the results reported here indicate that, while T. maritima shares core elements of the bacterial Heat-Shock Response with mesophiles, the thermal stress regulatory strategies of this organism differ significantly. However, it remains to be elucidated whether these differences are related to thermophilicity or phylogenetic placement.

  • Heat Shock Response by the hyperthermophilic archaeon Pyrococcus furiosus.
    Applied and Environmental Microbiology, 2003
    Co-Authors: Keith R. Shockley, Donald E. Ward, Swapnil R. Chhabra, Shannon B. Conners, Clemente I. Montero, Robert M. Kelly
    Abstract:

    Collective transcriptional analysis of Heat Shock Response in the hyperthermophilic archaeon Pyrococcus furiosus was examined by using a targeted cDNA microarray in conjunction with Northern analyses. Differential gene expression suggests that P. furiosus relies on a cooperative strategy of rescue (thermosome [Hsp60], small Heat Shock protein [Hsp20], and two VAT-related chaperones), proteolysis (proteasome), and stabilization (compatible solute formation) to cope with polypeptide processing during thermal stress.

Xingyu Wang - One of the best experts on this subject based on the ideXlab platform.

  • Differential regulation of interleukin-12 and interleukin-10 by Heat Shock Response in murine peritoneal macrophages.
    Biochemical and biophysical research communications, 2001
    Co-Authors: Xingyu Wang, Yunyun Zou, Yun Wang, Zongliang Chang
    Abstract:

    Heat Shock Response is a conserved stress Response and has been shown to have anti-inflammatory effects. We investigated the effect of Heat Shock Response on LPS-induced production of IL-12 and IL-10, which are two important cytokines playing contradictory roles in regulation of immune Response, by murine peritoneal macrophages. The data showed that induction of Heat Shock Response strongly suppressed LPS-induced production of IL-12 while augmented that of IL-10, suggesting the pleiotropic effects of Heat Shock Response on immune regulatory gene expression. Also, the novel observation on up-regulation of IL-10 by Heat Shock Response adds to the mechanism by which Heat Shock Response exerts its anti-inflammatory effects.

Mustafa Khammash - One of the best experts on this subject based on the ideXlab platform.

  • Module-based analysis of robustness tradeoffs in the Heat Shock Response system.
    PLoS computational biology, 2006
    Co-Authors: Hiroyuki Kurata, Hana El-samad, John C. Doyle, Carol A. Gross, Rei Iwasaki, Hisao Ohtake, Irina L. Grigorova, Mustafa Khammash
    Abstract:

    Biological systems have evolved complex regulatory mechanisms, even in situations where much simpler designs seem to be sufficient for generating nominal functionality. Using module-based analysis coupled with rigorous mathematical comparisons, we propose that in analogy to control engineering architectures, the complexity of cellular systems and the presence of hierarchical modular structures can be attributed to the necessity of achieving robustness. We employ the Escherichia coli Heat Shock Response system, a strongly conserved cellular mechanism, as an example to explore the design principles of such modular architectures. In the Heat Shock Response system, the sigma-factor σ32 is a central regulator that integrates multiple feedforward and feedback modules. Each of these modules provides a different type of robustness with its inherent tradeoffs in terms of transient Response and efficiency. We demonstrate how the overall architecture of the system balances such tradeoffs. An extensive mathematical exploration nevertheless points to the existence of an array of alternative strategies for the existing Heat Shock Response that could exhibit similar behavior. We therefore deduce that the evolutionary constraints facing the system might have steered its architecture toward one of many robustly functional solutions.

  • Feedback regulation of the Heat Shock Response in E. coli
    Lecture Notes in Control and Information Sciences, 2003
    Co-Authors: Hana El-samad, Mustafa Khammash, Hiroyuki Kurata, John C. Doyle
    Abstract:

    Systems Biology is an emerging new field defined as the study of biology as an integrated system of components that act interdependently to accomplish certain functions. This approach holds the promise of offering precious insight into aspects of biological organization that cannot be identified through a reductionist approach concerned solely with the study of individual molecules. In this work, we illustrate this viewpoint through the example of the bacterial Heat Shock Response. The Heat Shock Response is an important mechanism that combats harmful effects of an unmediated increase in temperature. Such an increase in temperature causes the unfolding or aggregation of the cellular proteins, which imposes a tremendous amount of stress on the cell. The Heat Shock Response is implemented through an elaborate system of controls whose purpose is to refold denatured proteins, therefore restoring their normal function. In this paper, we present a deterministic model for the Heat Shock Response. We use this model to gain insight into the design and performance objectives of this Response. We then provide a stochastic treatment based on the Stochastic Simulation Algorithm of Gillepsie [18]. This stochastic investigation validates the use of the deterministic approach in modeling the Heat Shock Response, and motivates the investigation of feedback structures that play a role in attenuating stochastic fluctuations.

  • Robustness analysis of the Heat Shock Response in E. coli
    Proceedings of the 2002 American Control Conference (IEEE Cat. No.CH37301), 2002
    Co-Authors: Hana El-samad, Mustafa Khammash, Hiroyuki Kurata, John C. Doyle
    Abstract:

    The bacterial Heat Shock Response refers to the mechanism by which bacteria react to a sudden increase in the ambient temperature of growth. The consequences of such an unmediated temperature increase at the cellular level is the unfolding, misfolding, or aggregation of cell proteins, which threatens the life of the cell. Cells respond to the Heat stress by initiating the production of Heat-Shock proteins whose function is to refold denatured proteins into their native states. The Heat Shock Response, through the elevated synthesis of molecular chaperones and proteases, enables the repair of protein damage and the degradation of aggregated proteins. In a previous work (Kurata et al., 2001), we have devised a dynamic model for the Heat Shock Response in E. coli. In the present paper, we provide a thorough discussion of the dynamical nature of this model. We use sensitivity analysis and simulation tools to illustrate the remarkable efficiency, robustness, and stability of the Heat Shock Response system.