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 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 DDRE-06. CELLULAR STRESS RESPONSE IN DIPG THERAPY

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii62-ii62
Author(s):  
Sreepradha Sridharan ◽  
Arif Harmanci ◽  
Robert Siddaway ◽  
Tara Dobson ◽  
Jyothishmathi Swaminathan ◽  
...  
Keyword(s):  
Stress Response ◽  
Single Cell ◽  
Synthetic Lethality ◽  
Clonal Evolution ◽  
Single Agent ◽  
Objective Response ◽  
Hdac Inhibitors ◽  
Pediatric Brain Tumor ◽  
Dominant Negative ◽  
Cellular Stress Response

Abstract Diffuse Intrinsic Pontine Glioma (DIPG) is an incurable pediatric brain tumor of the pons and brainstem. Therefore, there is a desperate need for new therapeutics. Genomic profiling of tumors identified a highly prevalent dominant negative somatic mutation at lysine (K)-27 in histone genes HIST1H3B and H3F3A. Clonal evolution modeling suggests these mutations are truncal, and studies have demonstrated their contribution to tumorigenesis. ONC201, a first-in-class DRD2 antagonist and ClpP agonist is an anticancer drug developed by Oncoceutics, which targets the unfolded protein response (UPR) and integrated stress response (ISR) signaling and is actively being investigated in patients with recurrent H3 K27M-mutant gliomas. In adults with recurrent glioma, single agent studies showed benign-safety, no dose-limiting toxicities and a durable objective response when administered orally. In addition, intra-tumoral drug levels exceeded therapeutic thresholds, and induced tumor cell apoptosis. Based on this and response seen in a pediatric patient with DIPG for whom compassionate use of ONC201 was approved, a multi-arm, non-randomized multi-institutional Phase I clinical trial (NCT03416530) is actively accruing patients. However, the strength of UPR and ISR in DIPGs and their effect on DIPG response to ONC201 is not known. Our group employed bulk/single cell transcriptomic and single cell proteomic approaches to demonstrate substantial heterogeneity in UPR and ISR signaling in human DIPG samples. Consistent with this, DIPG cell lines exhibited considerable variability in sensitivity to ONC201. Single cell profiling identified tumor sub-populations with significant proliferative capacity even after ONC201 exposure. Incomplete response promotes recurrence. To target these cells, we performed a synthetic lethality screen with a library of 360 FDA-approved CNS penetrant compounds, which identified HDAC inhibitors and DNA damage-inducing chemotherapy as having synergy with ONC201. Thus, we suggest that tumor heterogeneity impacts sensitivity to ONC201 and that this can be reduced by combination treatments.

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