scholarly journals Changes of cellular stress response related hsp70 and abcb1 transcript and Hsp70 protein levels in Siberian freshwater amphipods upon exposure to cadmium chloride in the lethal concentration range

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8635
Author(s):  
Marina V. Protopopova ◽  
Vasiliy V. Pavlichenko ◽  
Till Luckenbach
Keyword(s):  
Stress Response ◽  
Cadmium Chloride ◽  
Fold Increase ◽  
Cellular Stress Response ◽  
Lethal Concentration ◽  
Amphipod Species ◽  
Sensitive Species ◽  
Transcript Levels ◽  
Protein Levels ◽  
Hsp70 Protein

The induction of cellular stress response systems, heat shock protein hsp70/Hsp70 and multixenobiotic transporter abcb1, by cadmium chloride (CdCl2) was explored in amphipod species with different stress adaptation strategies from the Lake Baikal area. Based on the lethal concentrations (LC) of CdCl2, the sensitivities of the different species to CdCl2 were ranked (24 hr LC50 in mg/L CdCl2 (mean/95% confidence interval)): Gammarus lacustris (1.7/1.3–2.4) < Eulimnogammarus cyaneus (2.9/2.1–4.0) < Eulimnogammarus verrucosus (5.7/3.8–8.7) < Eulimnogammarus vittatus (18.1/12.4–26.6). Conjugated dienes, indicating lipid peroxidation, were significantly increased after 24 hr exposures to 5 mg/L CdCl2 only in the more CdCl2-sensitive species G. lacustris and E. cyaneus. Upon treatment with 0.54 to 5.8 mg/L CdCl2 for 1, 6 and 24 hrs, hsp70 transcript levels were generally more increased after the longer exposure times and in the more CdCl2-sensitive species. Relating the CdCl2 exposure concentrations to LCx values revealed that across the species the increases of hsp70 transcript levels were comparatively low (up to 2.6-fold) at CdCl2 concentrations ≤LC50. Relative hsp70 transcript levels were maximally increased in E. cyaneus by 5 mg/L CdCl2 ($\hat {=}$LC70) at 24 hrs (9.1-fold increase above the respective control). When G. lacustris was exposed to 5 mg/L CdCl2 ($\hat {=}$LC90) for 24 hrs, the increase in hsp70 was in comparison to E. cyaneus considerably less pronounced (3.0-fold increase in hsp70 levels relative to control). Upon exposure of amphipods to 5 mg/L CdCl2, increases in Hsp70 protein levels compared to untreated controls were highest in E. cyaneus at 1 and 6 hrs (5 mg/L CdCl2 $\hat {=}$ LC70) and in E. verrucosus at 24 hrs (5 mg/L CdCl2 $\hat {=}$ LC45). Thus, when the fold increases in Hsp70 protein levels in the different amphipod species were related to the respective species-specific LCx values a similar bell-shaped trend as for hsp70 transcript levels was seen across the species. Transcript levels of abcb1 in CdCl2exposed individuals of the different amphipod species varied up to 4.7-fold in relation to the respective controls. In contrast to hsp70/Hsp70, abcb1 transcripts in CdCl2 exposed individuals of the different amphipod species did not indicate similar levels of induction of abcb1 at equal LCx levels across the species. Induction of hsp70 and abcb1 genes and Hsp70 proteins by CdCl2 in the lethal concentration range shows that these cellular responses are rather insensitive to CdCl2 stress in the examined amphipod species. Furthermore, the increase of expression of these cellular defense systems at such high stress levels suggests that induction of these genes is not related to the maintenance of normal metabolism but to mitigation of the effects of severe toxic stress.

scholarly journals Investigation of cellular stress response related heat shock protein hsp70/Hsp70 and multixenobiotic transporter abcb1 in Siberian freshwater amphipods upon cadmium exposure

2019 ◽  
Author(s):  
Marina V. Protopopova ◽  
Vasiliy V. Pavlichenko ◽  
Till Luckenbach
Keyword(s):  
Stress Response ◽  
Cellular Stress Response ◽  
Amphipod Species ◽  
Sensitive Species ◽  
Transcript Levels ◽  
Gammarus Lacustris ◽  
Stress Response Genes ◽  
Hsp70 Protein ◽  
Freshwater Amphipods ◽  
Stress Gene

AbstractInduction of stress response genes hsp70 and abcb1 and Hsp70 protein by cadmium chloride (CdCl2) was explored in amphipod species with different stress adaptation strategies from the Lake Baikal area. Based on lethal concentrations (LC) the sensitivities to CdCl2 were ranked (24 hr LC50 – mg/L CdCl2): Gammarus lacustris (1.7) < Eulimnogammarus cyaneus (2.9) < E. verrucosus (8.3) < E. vittatus (18.2). Conjugated dienes indicating lipid peroxidation were significantly increased by 5 mg/L CdCl2 (24 hr exposure) only in G. lacustris and E. cyaneus. Upon treatment with 0.54 – 5.8 mg/L CdCl2hsp70 transcript levels were more increased in the toxicologically more sensitive species. Relating the exposure concentrations to LCx values revealed that across the species the increases of hsp70 transcript levels were comparatively low (up to 2.6-fold) up to LC50; at higher LCx values hsp70 induction was more pronounced (up to a 9.1-fold by 5 mg/L CdCl2 (≙LC70) in E. cyaneus). In contrast, abcb1 inductions did not correspond with CdCl2 LCx values across species; abcb1 induction was highest (4.7-fold) in E. verrucosus by 5.0 mg/L CdCl2 (≙LC45, 24 hr exposure). Induction of stress gene responses by lethal CdCl2 concentrations indicates that in the amphipods they are rather insensitive.

scholarly journals Reovirus Induces and Benefits from an Integrated Cellular Stress Response

2006 ◽  
Vol 80 (4) ◽  
pp. 2019-2033 ◽  
Author(s):  
Jennifer A. Smith ◽  
Stephen C. Schmechel ◽  
Arvind Raghavan ◽  
Michelle Abelson ◽  
Cavan Reilly ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Stress Response ◽  
Stress Responses ◽  
Cellular Stress Response ◽  
Initiation Factor ◽  
Viral Protein Synthesis ◽  
Protein Levels ◽  
Eif2α Phosphorylation ◽  
Infected Cells ◽  
Reovirus Replication

ABSTRACT Following infection with most reovirus strains, viral protein synthesis is robust, even when cellular translation is inhibited. To gain further insight into pathways that regulate translation in reovirus-infected cells, we performed a comparative microarray analysis of cellular gene expression following infection with two strains of reovirus that inhibit host translation (clone 8 and clone 87) and one strain that does not (Dearing). Infection with clone 8 and clone 87 significantly increased the expression of cellular genes characteristic of stress responses, including the integrated stress response. Infection with these same strains decreased transcript and protein levels of P58IPK, the cellular inhibitor of the eukaryotic initiation factor 2α (eIF2α) kinases PKR and PERK. Since infection with host shutoff-inducing strains of reovirus impacted cellular pathways that control eIF2α phosphorylation and unphosphorylated eIF2α is required for translation initiation, we examined reovirus replication in a variety of cell lines with mutations that impact eIF2α phosphorylation. Our results revealed that reovirus replication is more efficient in the presence of eIF2α kinases and phosphorylatable eIF2α. When eIF2α is phosphorylated, it promotes the synthesis of ATF4, a transcription factor that controls cellular recovery from stress. We found that the presence of this transcription factor increased reovirus yields 10- to 100-fold. eIF2α phosphorylation also led to the formation of stress granules in reovirus-infected cells. Based on these results, we hypothesize that eIF2α phosphorylation facilitates reovirus replication in two ways—first, by inducing ATF4 synthesis, and second, by creating an environment that places abundant reovirus transcripts at a competitive advantage for limited translational components.

scholarly journals Loss of FVIII Expression by Possible Interlinked Immune and Cellular Stress Response in Hemophilia A Mice Treated with AAV Gene Therapy

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Christopher Rogers ◽  
Thais Bertolini ◽  
Roland Herzog
Keyword(s):  
Gene Therapy ◽  
Stress Response ◽  
Hemophilia A ◽  
Genetic Disorder ◽  
Cellular Stress ◽  
Cellular Stress Response ◽  
Gradual Decline ◽  
Protein Levels ◽  
Time Treatment ◽  
Copy Numbers

Background  Hemophilia A is an X-linked genetic disorder caused by a mutation in the gene for factor VIII (FVIII) protein that reduces the ability of blood to clot. Clinical drug trials have shown the potential of adeno-associated virus (AAV) gene therapy as a one-time treatment for hemophilia A that can produce sustained high levels of FVIII. However, a gradual decline in protein levels has been observed in patients after 2-4 years. The hypothesis being tested in the Herzog Lab is that an interlinked immune and cellular stress response could be causing the loss of expression.     Methods  Two groups of Hemophilia A mice were administered AAV therapy, with one group receiving recurrent doses of Rapamycin. Blood samples were taken at weeks 4, 8, 12 and 14. Mice were euthanized at weeks 4, 8, and 14, and their livers were harvested. qPCR was used to measure AAV copy numbers and FVIII mRNA at 4, 8, and 14 weeks. Cryosections of mice livers from weeks 4, 8, and 14 were stained with antibodies for FVIII protein and CD8.    Results  qPCR showed roughly half as much AAV copy numbers in the rapamycin group at all time points, and little difference in FVIII mRNA between the groups. There was also a large decrease in AAV copy numbers and FVIII mRNA in both groups between 8 and 14 weeks. Immunohistochemistry showed less CD8 and more FVIII signal in mice treated with rapamycin.    Discussion  Experiments are currently being performed to investigate the decline in AAV copy numbers and mRNA between weeks 8 and 14. The immunohistochemistry data shows a relationship between increased FVIII protein levels and decreased cellular immune response but does not explain the gradual decline in FVIII. Further investigation into FVIII expression following AAV gene therapy could lead to an effective one-time treatment for hemophilia A.   

scholarly journals Multifactorial Attenuation of the Murine Heat Shock Response With Age

2019 ◽  
Vol 75 (10) ◽  
pp. 1846-1852 ◽  
Author(s):  
Donald A Jurivich ◽  
Gunjan D Manocha ◽  
Rachana Trivedi ◽  
Mary Lizakowski ◽  
Sharlene Rakoczy ◽  
...  
Keyword(s):  
Stress Response ◽  
Heat Shock ◽  
Protein Interactions ◽  
Messenger Rna ◽  
Physiological Stress ◽  
Cellular Stress Response ◽  
Heat Shock Factor 1 ◽  
Protein Levels ◽  
Age Related ◽  
Age Dependent

Abstract Age-dependent perturbation of the cellular stress response affects proteostasis and other key functions relevant to cellular action and survival. Central to age-related changes in the stress response is loss of heat shock factor 1 (HSF1)–DNA binding and transactivation properties. This report elucidates how age alters different checkpoints of HSF1 activation related to posttranslational modification and protein interactions. When comparing liver extracts from middle aged (12 M) and old (24 M) mice, significant differences are found in HSF1 phosphorylation and acetylation. HSF1 protein levels and messenger RNA decline with age, but its protein levels are stress-inducible and exempt from age-dependent changes. This surprising adaptive change in the stress response has additional implications for aging and chronic physiological stress that might explain an age-dependent dichotomy of HSF1 protein levels that are low in neurodegeneration and elevated in cancer.

scholarly journals Internal Ribosome Entry Site-mediated Translation of a Mammalian mRNA Is Regulated by Amino Acid Availability

2000 ◽  
Vol 276 (15) ◽  
pp. 12285-12291 ◽  
Author(s):  
James Fernandez ◽  
Ibrahim Yaman ◽  
Rangnath Mishra ◽  
William C. Merrick ◽  
Martin D. Snider ◽  
...  
Keyword(s):  
Amino Acid ◽  
Expression System ◽  
Fold Increase ◽  
Essential Amino Acids ◽  
Amino Acid Starvation ◽  
Cellular Stress Response ◽  
Entry Site ◽  
Cationic Amino Acid ◽  
Protein Levels ◽  
Amino Acid Availability

The cationic amino acid transporter, Cat-1, facilitates the uptake of the essential amino acids arginine and lysine. Amino acid starvation causes accumulation and increased translation of cat-1 mRNA, resulting in a 58-fold increase in protein levels and increased arginine uptake. A bicistronic mRNA expression system was used to demonstrate the presence of an internal ribosomal entry sequence (IRES) within the 5′-untranslated region of the cat-1 mRNA. This study shows that IRES-mediated translation of the cat-1 mRNA is regulated by amino acid availability. This IRES causes an increase in translation under conditions of amino acid starvation. In contrast, cap-dependent protein synthesis is inhibited during amino acid starvation, which is well correlated with decreased phosphorylation of the cap-binding protein, eIF4E. These findings reveal a new aspect of mammalian gene expression and regulation that provides a cellular stress response; when the nutrient supply is limited, the activation of IRES-mediated translation of mammalian mRNAs results in the synthesis of proteins essential for cell survival.

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