TY - JOUR
T1 - The Modulatory Role of sti-1 in Methylmercury-Induced Toxicity in Caenorhabditis elegans
AU - Ke, Tao
AU - Santamaria, Abel
AU - Farina, Marcelo
AU - Rocha, João B.T.
AU - Bowman, Aaron B.
AU - Aschner, Michael
N1 - Funding Information:
This work was supported by the National Institutes of Health to MA and ABB (NIEHS R01ES007331 and R01ES10653). Some strains were provided by the CGC, which is funded by NIH Office of Research Infrastructure Programs (P40 OD010440).
Publisher Copyright:
© 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2022/6
Y1 - 2022/6
N2 - Human exposure to the neurotoxin methylmercury (MeHg) poses a significant health risk to the development of the nervous system. The mechanisms of MeHg-induced neurotoxicity are associated with the disruption of cellular homeostasis, and include oxidative stress, loss of calcium homeostasis, and impaired protein quality control. The stress inducible protein 1 (STI-1) is involved in the regulation of protein quality control by acting as a protein cochaperone to maintain optimal protein unfolding and refolding. Here, we utilized the Caenorhabditis elegans (C. elegans) model of MeHg toxicity to characterize the role of the sti-1 gene in MeHg-induced toxicity. We showed that lifespan and developmental milestone timings were significantly altered in sti-1 knockout (KO) animals with MeHg exposure. However, knocking down sti-1 by RNAi did not result in an analogous effect for lifespan, but did still sensitize to delays in developmental milestone progression by acute MeHg, suggesting that insufficiency of sti-1 does not recapitulate all phenotypes of the null mutation. Furthermore, inhibition of ATP levels by MeHg exposure was modulated by sti-1. Considering that the skn-1/gst-4 pathway is highly involved in metal’s toxicity, such pathway was also explored in our model. We showed that sti-1 mutant worms exhibited impaired capacity to upregulate the antioxidant genes skn-1/gst-4, highlighting a central role of sti-1 in modulating antioxidant response. Lastly, we showed that loss-of-function mutation in the rrf-3 gene, which encodes a putative RNA-directed RNA polymerase, has significant effect in altering MeHg-induced toxicity by potentiating the animal’s detoxification system. Altogether, our novel data show an indispensable role of protein quality control in the defense against MeHg toxicity.
AB - Human exposure to the neurotoxin methylmercury (MeHg) poses a significant health risk to the development of the nervous system. The mechanisms of MeHg-induced neurotoxicity are associated with the disruption of cellular homeostasis, and include oxidative stress, loss of calcium homeostasis, and impaired protein quality control. The stress inducible protein 1 (STI-1) is involved in the regulation of protein quality control by acting as a protein cochaperone to maintain optimal protein unfolding and refolding. Here, we utilized the Caenorhabditis elegans (C. elegans) model of MeHg toxicity to characterize the role of the sti-1 gene in MeHg-induced toxicity. We showed that lifespan and developmental milestone timings were significantly altered in sti-1 knockout (KO) animals with MeHg exposure. However, knocking down sti-1 by RNAi did not result in an analogous effect for lifespan, but did still sensitize to delays in developmental milestone progression by acute MeHg, suggesting that insufficiency of sti-1 does not recapitulate all phenotypes of the null mutation. Furthermore, inhibition of ATP levels by MeHg exposure was modulated by sti-1. Considering that the skn-1/gst-4 pathway is highly involved in metal’s toxicity, such pathway was also explored in our model. We showed that sti-1 mutant worms exhibited impaired capacity to upregulate the antioxidant genes skn-1/gst-4, highlighting a central role of sti-1 in modulating antioxidant response. Lastly, we showed that loss-of-function mutation in the rrf-3 gene, which encodes a putative RNA-directed RNA polymerase, has significant effect in altering MeHg-induced toxicity by potentiating the animal’s detoxification system. Altogether, our novel data show an indispensable role of protein quality control in the defense against MeHg toxicity.
KW - Caenorhabditis elegans
KW - Metal toxicity
KW - Methylmercury
KW - Protein quality control
KW - Stress inducible protein 1
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U2 - 10.1007/s12640-022-00515-5
DO - 10.1007/s12640-022-00515-5
M3 - Article
C2 - 35471723
AN - SCOPUS:85128868490
VL - 40
SP - 837
EP - 846
JO - Neurotoxicity Research
JF - Neurotoxicity Research
SN - 1029-8428
IS - 3
ER -