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Adaptive response, evidence of cross-resistance and its potential clinical use.

Milisav I, Poljsak B, Suput D - Int J Mol Sci (2012)

Bottom Line: Stress responses are mechanisms used by organisms to adapt to and overcome stress stimuli.Studies have reported life-prolonging effects of a wide variety of so-called stressors, such as oxidants, heat shock, some phytochemicals, ischemia, exercise and dietary energy restriction, hypergravity, etc.These stress responses, which result in enhanced defense and repair and even cross-resistance against multiple stressors, may have clinical use and will be discussed, while the emphasis will be on the effects/cross-effects of oxidants.

View Article: PubMed Central - PubMed

Affiliation: Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloska 4, Ljubljana SI-1000, Slovenia; E-Mail: dusan.suput@mf.uni-lj.si ; Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, Ljubljana SI-1000, Slovenia; E-Mail: borut.poljsak@zf.uni-lj.si.

ABSTRACT
Organisms and their cells are constantly exposed to environmental fluctuations. Among them are stressors, which can induce macromolecular damage that exceeds a set threshold, independent of the underlying cause. Stress responses are mechanisms used by organisms to adapt to and overcome stress stimuli. Different stressors or different intensities of stress trigger different cellular responses, namely induce cell repair mechanisms, induce cell responses that result in temporary adaptation to some stressors, induce autophagy or trigger cell death. Studies have reported life-prolonging effects of a wide variety of so-called stressors, such as oxidants, heat shock, some phytochemicals, ischemia, exercise and dietary energy restriction, hypergravity, etc. These stress responses, which result in enhanced defense and repair and even cross-resistance against multiple stressors, may have clinical use and will be discussed, while the emphasis will be on the effects/cross-effects of oxidants.

No MeSH data available.


Related in: MedlinePlus

Cell repair and protection. Modulation of protein activity and expression has a key role in cell repair and protection during the adaptative stress response. The stress-modified regulation of transcription occurs, for example (1) by the induction of heat shock factors (HSF), which are the transcriptional regulators of genes encoding molecular chaperones and other stress proteins [80]; (2) by chromatin remodeling promoted by histone and DNA methyltransferases, demethylases, histone acetlytransferases and deacetylases [82]. The activity of histone deacetylases, like mammalian Sirtuin 1, is increased during nutrition stress [82,83]; (3) by the induction of various transcription factors [84–86]. The processes described above are interconnected at many levels; for example histone deacetylases sirtuins are involved in the regulation of transcription factors p53 and FOXO [87–90,91]. p53 has also non-transcripitonal activities; e.g., it interacts with apoptosis regulators [84]. The regulation of protein translation and activation is also crucial for stress-adaptation. The increased availability of a protein during the stress response can be achieved by reduced degradation (e.g., of p53), modifications in protein expression by translational regulation from the internal ribosome entry sites, upstream open reading frames, and modulation by micro RNA (miRNA) [14]. p53 and NF-κB regulate the transcription and processing of miRNA. The processes described are interconnected further; for example the different members of the heat shock protein family have a role in all of the described processes: in the activation of HSF, their transcription is stimulated during stress, they participate in repair processes and as anti-apoptotic proteins in combination with apoptosis regulators from the BCL2 family [3].
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f3-ijms-13-10771: Cell repair and protection. Modulation of protein activity and expression has a key role in cell repair and protection during the adaptative stress response. The stress-modified regulation of transcription occurs, for example (1) by the induction of heat shock factors (HSF), which are the transcriptional regulators of genes encoding molecular chaperones and other stress proteins [80]; (2) by chromatin remodeling promoted by histone and DNA methyltransferases, demethylases, histone acetlytransferases and deacetylases [82]. The activity of histone deacetylases, like mammalian Sirtuin 1, is increased during nutrition stress [82,83]; (3) by the induction of various transcription factors [84–86]. The processes described above are interconnected at many levels; for example histone deacetylases sirtuins are involved in the regulation of transcription factors p53 and FOXO [87–90,91]. p53 has also non-transcripitonal activities; e.g., it interacts with apoptosis regulators [84]. The regulation of protein translation and activation is also crucial for stress-adaptation. The increased availability of a protein during the stress response can be achieved by reduced degradation (e.g., of p53), modifications in protein expression by translational regulation from the internal ribosome entry sites, upstream open reading frames, and modulation by micro RNA (miRNA) [14]. p53 and NF-κB regulate the transcription and processing of miRNA. The processes described are interconnected further; for example the different members of the heat shock protein family have a role in all of the described processes: in the activation of HSF, their transcription is stimulated during stress, they participate in repair processes and as anti-apoptotic proteins in combination with apoptosis regulators from the BCL2 family [3].

Mentions: In addition to clearance of damaged macromolecules (described above), cellular repair is mediated through changed gene expression patterns [77], induction of molecular chaperones [78], growth arrest, etc. (Figure 3). The alterations of transcription during stress are often mediated by micro ribonucleic acids (miRNAs) (reviewed in [14]). These are short, noncoding, RNAs of about 22 nucleotides that bind to mRNAs and either accelerate their degradation or inhibit the translation of mRNA, i.e., modulate the stability and/or translational potential of their targets. The stress responses modify the synthesis of miRNAs. The level of target gene repression depends on the relative concentrations of the genes inhibited by a miRNA and of a particular miRNA [79]. The outcome of miRNA repression depends also on the interactions with stress proteins that can modulate the activity of miRNA protein complexes, e.g., by inhibiting the access to target mRNA. The proteins transformation-related protein 53 (p53) and NF-κB (section 2.4) regulate the transcription and processing of miRNA. The subcellular location of miRNA can change as a consequence of stress. Most miRNA are diffused in the cytoplasm; they have to associate with the member of the Argonaute protein family for activity. After a maturation process at the Argonaute protein, mature miRNAs guide the Argonaute-containing complexes to target sites at mRNAs that are partially complementary to the miRNA sequence, and induce repression of gene expression at the level of mRNA stability or translation. miRNA are synthesized in about two hours, while the mature miRNA can peak in about 24 h. Therefore, the action of miRNA is delayed and can sometimes time the stress response. This is important in acute stress responses, such as during inflammation. Nutrient stress, temperature shock, DNA damage and hypoxia can lead to changes in gene expression by shutdown and reprogramming of protein synthesis through selective recruitment of ribosomes to mRNAs [77]. This is regulated by elements in untranslated regions of mRNAs, like internal ribosome entry segments, upstream open reading frames and miRNA target sites [14].


Adaptive response, evidence of cross-resistance and its potential clinical use.

Milisav I, Poljsak B, Suput D - Int J Mol Sci (2012)

Cell repair and protection. Modulation of protein activity and expression has a key role in cell repair and protection during the adaptative stress response. The stress-modified regulation of transcription occurs, for example (1) by the induction of heat shock factors (HSF), which are the transcriptional regulators of genes encoding molecular chaperones and other stress proteins [80]; (2) by chromatin remodeling promoted by histone and DNA methyltransferases, demethylases, histone acetlytransferases and deacetylases [82]. The activity of histone deacetylases, like mammalian Sirtuin 1, is increased during nutrition stress [82,83]; (3) by the induction of various transcription factors [84–86]. The processes described above are interconnected at many levels; for example histone deacetylases sirtuins are involved in the regulation of transcription factors p53 and FOXO [87–90,91]. p53 has also non-transcripitonal activities; e.g., it interacts with apoptosis regulators [84]. The regulation of protein translation and activation is also crucial for stress-adaptation. The increased availability of a protein during the stress response can be achieved by reduced degradation (e.g., of p53), modifications in protein expression by translational regulation from the internal ribosome entry sites, upstream open reading frames, and modulation by micro RNA (miRNA) [14]. p53 and NF-κB regulate the transcription and processing of miRNA. The processes described are interconnected further; for example the different members of the heat shock protein family have a role in all of the described processes: in the activation of HSF, their transcription is stimulated during stress, they participate in repair processes and as anti-apoptotic proteins in combination with apoptosis regulators from the BCL2 family [3].
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3472714&req=5

f3-ijms-13-10771: Cell repair and protection. Modulation of protein activity and expression has a key role in cell repair and protection during the adaptative stress response. The stress-modified regulation of transcription occurs, for example (1) by the induction of heat shock factors (HSF), which are the transcriptional regulators of genes encoding molecular chaperones and other stress proteins [80]; (2) by chromatin remodeling promoted by histone and DNA methyltransferases, demethylases, histone acetlytransferases and deacetylases [82]. The activity of histone deacetylases, like mammalian Sirtuin 1, is increased during nutrition stress [82,83]; (3) by the induction of various transcription factors [84–86]. The processes described above are interconnected at many levels; for example histone deacetylases sirtuins are involved in the regulation of transcription factors p53 and FOXO [87–90,91]. p53 has also non-transcripitonal activities; e.g., it interacts with apoptosis regulators [84]. The regulation of protein translation and activation is also crucial for stress-adaptation. The increased availability of a protein during the stress response can be achieved by reduced degradation (e.g., of p53), modifications in protein expression by translational regulation from the internal ribosome entry sites, upstream open reading frames, and modulation by micro RNA (miRNA) [14]. p53 and NF-κB regulate the transcription and processing of miRNA. The processes described are interconnected further; for example the different members of the heat shock protein family have a role in all of the described processes: in the activation of HSF, their transcription is stimulated during stress, they participate in repair processes and as anti-apoptotic proteins in combination with apoptosis regulators from the BCL2 family [3].
Mentions: In addition to clearance of damaged macromolecules (described above), cellular repair is mediated through changed gene expression patterns [77], induction of molecular chaperones [78], growth arrest, etc. (Figure 3). The alterations of transcription during stress are often mediated by micro ribonucleic acids (miRNAs) (reviewed in [14]). These are short, noncoding, RNAs of about 22 nucleotides that bind to mRNAs and either accelerate their degradation or inhibit the translation of mRNA, i.e., modulate the stability and/or translational potential of their targets. The stress responses modify the synthesis of miRNAs. The level of target gene repression depends on the relative concentrations of the genes inhibited by a miRNA and of a particular miRNA [79]. The outcome of miRNA repression depends also on the interactions with stress proteins that can modulate the activity of miRNA protein complexes, e.g., by inhibiting the access to target mRNA. The proteins transformation-related protein 53 (p53) and NF-κB (section 2.4) regulate the transcription and processing of miRNA. The subcellular location of miRNA can change as a consequence of stress. Most miRNA are diffused in the cytoplasm; they have to associate with the member of the Argonaute protein family for activity. After a maturation process at the Argonaute protein, mature miRNAs guide the Argonaute-containing complexes to target sites at mRNAs that are partially complementary to the miRNA sequence, and induce repression of gene expression at the level of mRNA stability or translation. miRNA are synthesized in about two hours, while the mature miRNA can peak in about 24 h. Therefore, the action of miRNA is delayed and can sometimes time the stress response. This is important in acute stress responses, such as during inflammation. Nutrient stress, temperature shock, DNA damage and hypoxia can lead to changes in gene expression by shutdown and reprogramming of protein synthesis through selective recruitment of ribosomes to mRNAs [77]. This is regulated by elements in untranslated regions of mRNAs, like internal ribosome entry segments, upstream open reading frames and miRNA target sites [14].

Bottom Line: Stress responses are mechanisms used by organisms to adapt to and overcome stress stimuli.Studies have reported life-prolonging effects of a wide variety of so-called stressors, such as oxidants, heat shock, some phytochemicals, ischemia, exercise and dietary energy restriction, hypergravity, etc.These stress responses, which result in enhanced defense and repair and even cross-resistance against multiple stressors, may have clinical use and will be discussed, while the emphasis will be on the effects/cross-effects of oxidants.

View Article: PubMed Central - PubMed

Affiliation: Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloska 4, Ljubljana SI-1000, Slovenia; E-Mail: dusan.suput@mf.uni-lj.si ; Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, Ljubljana SI-1000, Slovenia; E-Mail: borut.poljsak@zf.uni-lj.si.

ABSTRACT
Organisms and their cells are constantly exposed to environmental fluctuations. Among them are stressors, which can induce macromolecular damage that exceeds a set threshold, independent of the underlying cause. Stress responses are mechanisms used by organisms to adapt to and overcome stress stimuli. Different stressors or different intensities of stress trigger different cellular responses, namely induce cell repair mechanisms, induce cell responses that result in temporary adaptation to some stressors, induce autophagy or trigger cell death. Studies have reported life-prolonging effects of a wide variety of so-called stressors, such as oxidants, heat shock, some phytochemicals, ischemia, exercise and dietary energy restriction, hypergravity, etc. These stress responses, which result in enhanced defense and repair and even cross-resistance against multiple stressors, may have clinical use and will be discussed, while the emphasis will be on the effects/cross-effects of oxidants.

No MeSH data available.


Related in: MedlinePlus