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Jae-seong Lee - One of the best experts on this subject based on the ideXlab platform.
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hydrophobic surface coating can reduce toxicity of zinc oxide nanoparticles to the marine copepod Tigriopus japonicus
Environmental Science & Technology, 2021Co-Authors: Hyemin Kang, Jae-seong Lee, Kenneth M.y. Leung, Guangjie Zhou, Racliffe Weng Seng Lai, Mana M N Yung, Aleksandra B DjurisicAbstract:Coated zinc oxide nanoparticles (ZnO-NPs) are more commonly applied in commercial products but current risk assessments mostly focus on bare ZnO-NPs. To investigate the impacts of surface coatings, this study examined acute and chronic toxicities of six chemicals, including bare ZnO-NPs, ZnO-NPs with three silane coatings of different hydrophobicity, zinc oxide bulk particles (ZnO-BKs), and zinc ions (Zn-IONs), toward a marine copepod, Tigriopus japonicus. In acute tests, bare ZnO-NPs and hydrophobic ZnO-NPs were less toxic than hydrophilic ZnO-NPs. Analyses of the copepod's antioxidant gene expression suggested that such differences were governed by hydrodynamic size and ion dissolution of the particles, which affected zinc bioaccumulation in copepods. Conversely, all test particles, except the least toxic hydrophobic ZnO-NPs, shared similar chronic toxicity as Zn-IONs because they mostly dissolved into zinc ions at low test concentrations. The metadata analysis, together with our test results, further suggested that the toxicity of coated metal-associated nanoparticles could be predicted by the hydrophobicity and density of their surface coatings. This study evidenced the influence of surface coatings on the physicochemical properties, toxicity, and toxic mechanisms of ZnO-NPs and provided insights into the toxicity prediction of coated nanoparticles from their coating properties to improve their future risk assessment and management.
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sunscreens containing zinc oxide nanoparticles can trigger oxidative stress and toxicity to the marine copepod Tigriopus japonicus
Marine Pollution Bulletin, 2020Co-Authors: Stella W Y Wong, Jae-seong Lee, Jeonghoon Han, Kevin W.h. Kwok, Kenneth M.y. Leung, Guangjie Zhou, Priscilla T Y LeungAbstract:Abstract The study, for the first time, evaluated the leaching rate of zinc oxide nanoparticles (nZnO) from human skins which were applied with three commercial sunscreens containing nZnO as an active ingredient. The leaching rate of nZnO varied greatly among the sunscreens, with a range of 8–72% (mean ± SD: 45% ± 33%). We further investigated their toxicities to the marine copepod Tigriopus japonicus. We found that 96-h median lethal concentrations of the three sunscreens to T. japonicus were > 5000, 230.6, and 43.0 mg chemical L−1, respectively, equivalent to Zn2+ concentrations at >82.5, 3.2, and 1.2 mg Zn L−1, respectively. Exposure to the individual sunscreens at environmentally realistic concentrations for 96 h led to up-regulation of antioxidant genes in T. japonicus, while they triggered the release of reactive oxygen species based on the results of in vivo assays. Evidently, these nZnO-included sunscreens can cause oxidative stress and hence pose risk to marine organisms.
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The genome of the harpacticoid copepod Tigriopus japonicus: Potential for its use in marine molecular ecotoxicology.
Aquatic toxicology (Amsterdam Netherlands), 2020Co-Authors: Changbum Jeong, Jun Chul Park, Minghua Wang, Heum Gi Park, Bo-young Lee, Beom-soon Choi, Min-sub Kim, Duck-hyun Kim, Jae-seong LeeAbstract:The copepod Tigriopus japonicus has been widely used as an experimental species in the field of ecotoxicology. We have sequenced and assembled the whole genome of T. japonicus with comparative analysis of gene families that represent detoxification phases in two additional public genomes of Tigriopus spp., namely, T. californicus and T. kingsejongensis. The total length of the T. japonicus assembled genome was 196.6 Mb with an N50 value of 10.65 Mb and consisted of 339 scaffolds and 25,143 annotated genes. The detoxification gene families encoding cytochrome P450s (CYP450s), glutathione S-transferases (GSTs), and ATP-binding cassette (ABC) proteins in Tigriopus spp. have shown species-dependent diversity in several gene sets, suggesting that these genes have undergone a species-specific expansion to increase their fitness to different marine habitats and environmental pressures. Our study will provide a better understanding of the detoxification system in Tigriopus spp. and will contribute to various areas of research, including ecotoxicology.
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effects of atrazine on life parameters oxidative stress and ecdysteroid biosynthetic pathway in the marine copepod Tigriopus japonicus
Aquatic Toxicology, 2019Co-Authors: Deokseo Yoon, Jun Chul Park, Jae-seong Lee, Heum Gi Park, Jeonghoon HanAbstract:Atrazine is a widely used pesticide which acts as an endocrine disruptor in various organisms. The aim of this study was to investigate adverse effects of atrazine on life parameters, oxidative stress, and ecdysteroid biosynthetic pathway in the marine copepod Tigriopus japonicus. In T. japonicus, no mortality was shown in response to atrazine up to 20 mg/L in acute toxicity assessment. In nauplii, retardation in the growth and prolonged molting and metamorphosis resulted under chronic exposure of atrazine at 20 mg/L. In addition, body sizes of T. japonicus nauplii were significantly decreased (P < 0.01 in length and P < 0.001 in width) in response to 20 mg/L of atrazine. Furthermore, atrazine induced oxidative stress by the generation of reactive oxygen species at all concentrations compared to the control in the nauplii. Also, significant increase in glutathione-S transferase activity was observed in adult T. japonicus at low concentration of atrazine. To understand effects of atrazine on ecdysteroid biosynthetic pathway-involved genes (e.g., neverland, CYP307E1, CYP306A1, CYP302A1, CYP3022A1 [CYP315A1], CYP314A1, and CYP18D1) were examined with mRNA expressions of ecdysone receptor (EcR) and ultraspiracle (USP) in response to 20 mg/L atrazine in nauplii and adults. In the nauplii, these genes were significantly downregulated (P < 0.05) in response to atrazine, compared to the control but not in the adult T. japonicus. These results suggest that atrazine can interfere in vivo life parameters by oxidative stress-induced retrogression and ecdysteroid biosynthetic pathway in this species.
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effects of ocean acidification on life parameters and antioxidant system in the marine copepod Tigriopus japonicus
Aquatic Toxicology, 2019Co-Authors: Younghwan Lee, Changbum Jeong, Hyemin Kang, Minghua Wang, Min-sub Kim, Jeong Ha Kim, Jae-seong LeeAbstract:Ocean acidification (OA) is caused by alteration of global ocean carbon chemistry due to the increased pCO2 in the atmosphere and caused deleterious impacts on the marine ecosystem. Although various detrimental effects of OA were reported in marine organisms, the potential impact of OA on aquatic invertebrates still remains largely unknown. Here, we examined changes in life parameters and antioxidant system in response to low pH (7.5 and 7) in the marine copepod Tigriopus japonicus. Exposures to lower pHs (pH 7.5 and 7.0) of copepods resulted in lengthening of the developmental time with decreased fecundity and body length. Also, they showed increased reactive oxygen species contents with enhanced glutathione S-transferase and glutathione reductase activities but decreased glutathione peroxidase and superoxide dismutase activities in pH-dependent manner, indicating that OA exposure caused disturbance of the redox system in T. japonicus. Among several oxidative stress-related genes, GSTs2b was significantly up-regulated in response to OA. These findings will be helpful for a better understanding on the potential impact of OA on life parameters and antioxidant system in the marine copepod T. japonicus.
Jeonghoon Han - One of the best experts on this subject based on the ideXlab platform.
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effects of toxic dinoflagellate alexandrium minutum on the expression of detoxification related genes in the marine copepod Tigriopus japonicus
Journal of Experimental Marine Biology and Ecology, 2021Co-Authors: Jeonghoon Han, Joon Sang Park, Yeun Park, Jihoon Lee, Young-ung Choi, Hyeon Ho Shin, Kyun-woo LeeAbstract:Abstract To understand the effects of the toxic dinoflagellate Alexandrium minutum on the marine copepod Tigriopus japonicus , we assessed acute toxicity and swimming behavior (swimming speed, swimming distance, and swimming path trajectory) in response to A. minutum exposure. No significant changes in survival and swimming behavior were observed in response to A. minutum. Therefore, to validate the effects of A. minutum on the molecular defense response of T. japonicus, we measured mRNA expression levels of detoxification-related genes (phase I cytochrome P450s [CYPs], and phase II glutathione-S transferases [GSTs]) in response to A. minutum. The mRNA expression levels of these detoxification-related genes (CYPs and GSTs) were significantly up-regulated and down-regulated (P genes are likely to play crucial roles in detoxification mechanisms in T. japonicus, resulting in no significant changes in the survival and swimming behavior of this marine copepod in response to A. minutum exposure.
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Effects of paralytic shellfish poisoning toxin-producing dinoflagellate Gymnodinium catenatum on the marine copepod Tigriopus japonicus.
Marine pollution bulletin, 2020Co-Authors: Jeonghoon Han, Joon Sang Park, Yeun Park, Jihoon Lee, Hyun Ho Shin, Kyun-woo LeeAbstract:Abstracts To understand how the marine copepod Tigriopus japonicus responds to the toxic marine dinoflagellate Gymnodinium catenatum, we assessed acute toxicity and investigated swimming behavior parameters (e.g., swimming speed, swimming path trajectory, and swimming distance) in response to G. catenatum exposure. In addition, the mRNA expression levels of detoxification-related genes (e.g., phase I cytochrome P450 [CYP] and phase II glutathione-S transferase [GST]) were measured in G. catenatum-exposed copepods. No significant change in survival was observed in response to G. catenatum, but swimming speed was significantly decreased (P
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sunscreens containing zinc oxide nanoparticles can trigger oxidative stress and toxicity to the marine copepod Tigriopus japonicus
Marine Pollution Bulletin, 2020Co-Authors: Stella W Y Wong, Jae-seong Lee, Jeonghoon Han, Kevin W.h. Kwok, Kenneth M.y. Leung, Guangjie Zhou, Priscilla T Y LeungAbstract:Abstract The study, for the first time, evaluated the leaching rate of zinc oxide nanoparticles (nZnO) from human skins which were applied with three commercial sunscreens containing nZnO as an active ingredient. The leaching rate of nZnO varied greatly among the sunscreens, with a range of 8–72% (mean ± SD: 45% ± 33%). We further investigated their toxicities to the marine copepod Tigriopus japonicus. We found that 96-h median lethal concentrations of the three sunscreens to T. japonicus were > 5000, 230.6, and 43.0 mg chemical L−1, respectively, equivalent to Zn2+ concentrations at >82.5, 3.2, and 1.2 mg Zn L−1, respectively. Exposure to the individual sunscreens at environmentally realistic concentrations for 96 h led to up-regulation of antioxidant genes in T. japonicus, while they triggered the release of reactive oxygen species based on the results of in vivo assays. Evidently, these nZnO-included sunscreens can cause oxidative stress and hence pose risk to marine organisms.
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effects of atrazine on life parameters oxidative stress and ecdysteroid biosynthetic pathway in the marine copepod Tigriopus japonicus
Aquatic Toxicology, 2019Co-Authors: Deokseo Yoon, Jun Chul Park, Jae-seong Lee, Heum Gi Park, Jeonghoon HanAbstract:Atrazine is a widely used pesticide which acts as an endocrine disruptor in various organisms. The aim of this study was to investigate adverse effects of atrazine on life parameters, oxidative stress, and ecdysteroid biosynthetic pathway in the marine copepod Tigriopus japonicus. In T. japonicus, no mortality was shown in response to atrazine up to 20 mg/L in acute toxicity assessment. In nauplii, retardation in the growth and prolonged molting and metamorphosis resulted under chronic exposure of atrazine at 20 mg/L. In addition, body sizes of T. japonicus nauplii were significantly decreased (P < 0.01 in length and P < 0.001 in width) in response to 20 mg/L of atrazine. Furthermore, atrazine induced oxidative stress by the generation of reactive oxygen species at all concentrations compared to the control in the nauplii. Also, significant increase in glutathione-S transferase activity was observed in adult T. japonicus at low concentration of atrazine. To understand effects of atrazine on ecdysteroid biosynthetic pathway-involved genes (e.g., neverland, CYP307E1, CYP306A1, CYP302A1, CYP3022A1 [CYP315A1], CYP314A1, and CYP18D1) were examined with mRNA expressions of ecdysone receptor (EcR) and ultraspiracle (USP) in response to 20 mg/L atrazine in nauplii and adults. In the nauplii, these genes were significantly downregulated (P < 0.05) in response to atrazine, compared to the control but not in the adult T. japonicus. These results suggest that atrazine can interfere in vivo life parameters by oxidative stress-induced retrogression and ecdysteroid biosynthetic pathway in this species.
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genome wide identification and expression of the entire 52 glutathione s transferase gst subfamily genes in the cu2 exposed marine copepods Tigriopus japonicus and paracyclopina nana
Aquatic Toxicology, 2019Co-Authors: Jun Chul Park, Heum Gi Park, Jeonghoon Han, Unki Hwang, Minchul Lee, Deokseo Yoon, Jae-seong LeeAbstract:Abstract In this study, the entire glutathione S-transferases (GSTs), the major phase II detoxification enzyme, were identified in two marine copepod species Tigriopus japonicus and Paracyclopina nana. The genome-wide identification of GSTs in T. japonicus and P. nana resulted in 32 and 20 GSTs in total, respectively. Among the identified GSTs, two specific classes of GSTs, specifically sigma and delta/epsilon GSTs were the dominant form of cytosolic GSTs in T. japonicus, while delta/epsilon and mu classes were dominant cytosolic GSTs in P. nana. In addition, Membrane-Associated Proteins in Eicosanoid and Glutathione metabolism (MAPEG) family were found in relatively higher proportion compared to other classes. Moreover, sigma, delta/epsilon, and microsomal GSTs have shown to expand through tandem duplication. To validate the detoxification function of the identified GSTs, both copepods were exposed to copper (Cu2+) and the reactive oxygen species (ROS) level and GST activity were measured. With integration of phylogenetic analysis and xenobiotic-mediated GST mRNA expression patterns along with previous enzymatic activities, the functional divergence among species-specific GST genes was clearly observed. This study covers full identification of GST classes in two marine copepod species and their important role in marine environmental ecotoxicology.
Daesik Hwang - One of the best experts on this subject based on the ideXlab platform.
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ultraviolet b radiation induces impaired lifecycle traits and modulates expression of cytochrome p450 cyp genes in the copepod Tigriopus japonicus
Aquatic Toxicology, 2017Co-Authors: Jayesh Puthumana, Jun Chul Park, Daesik Hwang, Jeonghoon Han, Hui-su Kim, Minchul Lee, Jae-seong LeeAbstract:To evaluate the effects of ultraviolet B (UV-B) radiation at the developmental, reproductive, and molecular levels in aquatic invertebrates, we measured UV-B-induced acute toxicity, impairments in developmental and reproductive traits, and UV-B interaction with the entire family of cytochrome P450 (CYP) genes in the intertidal benthic copepod Tigriopus japonicus. We found a significant, dose-dependent reduction (P<0.05) in the survival of T. japonicus that began as a developmental delay and decreased fecundity. The 48h LD10 and LD50 were 1.35 and 1.84kJ/m2, and the CYP inhibitor (PBO) elevated mortality, confirming the involvement of CYP genes in UV-B induced toxicity. Low-dose UV-B (1.5kJ/m2) induced developmental delays, and higher doses (6-18kJ/m2) caused reproductive impairments in ovigerous females. The significant up-regulation of CYP genes belonging to clans 2/3/MT/4/20 in T. japonicus exposed to UV-B (12kJ/m2) confirmed molecular interaction between UV-B and CYP genes. Moreover, orphan CYPs, such as CYP20A1, provide good insight on the deorphanization of invertebrate CYPs. Overall, these results demonstrate the involvement of UV-B radiation in the expression of all the CYP genes in T. japonicus and their susceptibility to UV-B radiation. This will provide a better understanding of the mechanistic effects of UV-B in copepods through the predicted AhR-mediated up-regulation of CYP genes.
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wafs lead molting retardation of naupliar stages with down regulated expression profiles of chitin metabolic pathway and related genes in the copepod Tigriopus japonicus
Comparative Biochemistry and Physiology C-toxicology & Pharmacology, 2017Co-Authors: Daesik Hwang, Il-chan Kim, Jeonghoon Han, Hui-su Kim, Minchul Lee, Dohyun Kyung, Jayesh Puthumana, Jae-seong LeeAbstract:Oil pollution is considered being disastrous to marine organisms and ecosystems. As molting is critical in the developmental process of arthropods in general and copepods, in particular, the impact will be adverse if the target of spilled oil is on molting. Thus, we investigated the harmful effects of water accommodated fractions (WAFs) of crude oil with an emphasis on inhibition of chitin metabolic pathways related genes and developmental retardation in the copepod Tigriopus japonicus. Also, we analysed the ontology and domain of chitin metabolic pathway genes and mRNA expression patterns of developmental stage-specific genes. Further, the developmental retardation followed by transcriptional modulations in nuclear receptor genes (NR) and chitin metabolic pathway-related genes were observed in the WAFs-exposed T. japonicus. As a result, the developmental time was found significantly (P < 0.05) delayed in response to 40% WAFs in comparison with that of control. Moreover, the NR gene, HR3 and chitinases (CHT9 and CHT10) were up-regulated in N4–5 stages, while chitin synthase genes (CHS-1, CHS-2-1, and CHS-2-2) down-regulated in response to WAFs. In brief, a high concentration of WAFs repressed nuclear receptor genes but elicited activation of some of the transcription factors at low concentration of WAFs, resulting in suppression of chitin synthesis. Thus, we suggest that WAF can lead molting retardation of naupliar stages in T. japonicus through down-regulations of chitin metabolism. These findings will provide a better understanding of the mode of action of chitin biosynthesis associated with molting mechanism in WAF-exposed T. japonicus.
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a brominated flame retardant 2 2 4 4 tetrabrominated diphenyl ether bde 47 leads to lipogenesis in the copepod Tigriopus japonicus
Aquatic Toxicology, 2016Co-Authors: Minchul Lee, Jun Chul Park, Hyemin Kang, Daesik Hwang, Duck-hyun Kim, Jeonghoon Han, Eunji Won, Seunghwi Lee, Jae-seong LeeAbstract:De novo lipogenesis (DNL) is a fatty acid synthesis process that requires several genes, including sterol regulatory element binding protein (SREBP), ATP-citrate lyase (ACLY), and acetyl-CoA carboxylase (ACC). DNL up-regulation is able to induce fat accumulation through an increase in fatty acids. To investigate the relationship between DNL up-regulation and the accumulation of fatty acids and lipid droplets in response to 2,2',4,4' tetrabrominated diphenyl ether (BDE-47), we examined DNL in the copepod Tigriopus japonicus. Transcription levels of DNL-related genes were increased after exposure to 2.5μg/L BDE-47 for 24h. After exposure to 2.5μg/L BDE-47, palmitic acid was significantly increased (P<0.05) at days 1 and 4, along with upregulation of fatty acid synthesis-related genes (e.g., desaturases and elongases). However, docosahexaenoic acid and arachidonic acid were down-regulated at days 1 and 4, showing an antagonistic effect. Lipid droplet area significantly increased in Nile red staining analysis after 24h of exposure to 2.5μg/L BDE-47 in T. japonicus, while DNL was down-regulated in response to 500μM salicylate (a lipogenesis inhibitor), indicating that BDE-47 exposure is closely associated with an increase in fatty acids in this copepod. This study provides a better understanding of the effects of BDE-47 on DNL in copepods.
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bde 47 causes developmental retardation with down regulated expression profiles of ecdysteroid signaling pathway involved nuclear receptor nr genes in the copepod Tigriopus japonicus
Aquatic Toxicology, 2016Co-Authors: Daesik Hwang, Changbum Jeong, Duck-hyun Kim, Jeonghoon Han, Eunji Won, Unki Hwang, B Zhou, Joonho Choe, Jae-seong LeeAbstract:2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47) is a persistent organic pollutant (POP) in marine environments. Despite its adverse effects (e.g. developmental retardation) in ecdysozoa, the effects of BDE-47 on transcription of ecdysteroid signaling pathway-involved-nuclear receptor (NR) genes and metamorphosis-related genes have not been examined in copepods. To examine the deleterious effect of BDE-47 on copepod molting and metamorphosis, BDE-47 was exposed to the harpacticoid copepod Tigriopus japonicus, followed by monitoring developmental retardation and transcriptional alteration of NR genes. The developmental rate was significantly inhibited (P < 0.05) in response to BDE-47 and the agricultural insecticide gamma-hexachlorocyclohexane. Conversely, the ecdysteroid agonist ponasterone A (PoA) led to decreased molting and metamorphosis time (P < 0.05) from the nauplius stage to the adult stage. In particular, expression profiles of all NR genes were the highest at naupliar stages 5–6 except for SVP, FTZ-F1, and HR96 genes. Nuclear receptor USP, HR96, and FTZ-F1 genes also showed significant sex differences (P < 0.05) in gene expression levels over different developmental stages, indicating that these genes may be involved in vitellogenesis. NR gene expression patterns showed significant decreases (P < 0.05) in response to BDE-47 exposure, implying that molting and metamorphosis retardation is likely associated with NR gene expression. In summary, BDE-47 leads to molting and metamorphosis retardation and suppresses transcription of NR genes. This information will be helpful in understanding the molting and metamorphosis delay mechanism in response to BDE-47 exposure.
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effects of multi walled carbon nanotube mwcnt on antioxidant depletion the erk signaling pathway and copper bioavailability in the copepod Tigriopus japonicus
Aquatic Toxicology, 2016Co-Authors: Jin Wuk Lee, Hyemin Kang, Daesik Hwang, Duck-hyun Kim, Eunji Won, Sujae Lee, Rae Kwon Kim, Jae-seong LeeAbstract:Multi-walled carbon nanotubes (MWCNTs) are nanoparticles widely applicable in various industrial fields. However, despite the usefulness of MWCNTs in industry, their oxidative stress-induced toxicity, combined toxicity with metal, and mitogen-activated protein kinase (MAPK) activation have not been widely investigated in marine organisms. We used the intertidal copepod Tigriopus japonicus as a test organism to demonstrate the adverse effects induced by MWCNTs in aquatic test organisms. The dispersion of the MWCNTs in seawater was maintained over 48 h without aggregation. MWCNTs caused a decrease in acute copper toxicity compared to the copper-only group in response to 20 and 100 mg/L MWCNTs, but not in response to 4 mg/L MWCNT, indicating that MWCNT may suppress acute copper toxicity. Reactive oxygen species (ROS) and enzymatic activities of glutathione S-transferase (GST) and catalase were significantly down-regulated in response to 100 mg/L MWCNT exposure. Glutathione (GSH) and glutathione reductase (GR) activity did not change significantly, indicating that MWCNTs may cause failure of the antioxidant system in T. japonicus. However, MWCNT induced extracellular signal-regulated kinase (ERK) activation without p38 and c-jun NH2-terminal kinase (JNK) activation, suggesting that ERK activation plays a key role in cell signaling pathways downstream of CNT exposure. This suggests that this pathway can be used as a biomarker for CNT exposure in T. japonicus. This study provides a better understanding of the cellular-damage response to MWCNTs.
Jaesung Rhee - One of the best experts on this subject based on the ideXlab platform.
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identification and molecular characterization of nitric oxide synthase nos gene in the intertidal copepod Tigriopus japonicus
Gene, 2016Co-Authors: Changbum Jeong, Hyemin Kang, Jung Soo Seo, Heum Gi Park, Jaesung Rhee, Jae-seong LeeAbstract:In copepods, no information has been reported on the structure or molecular characterization of the nitric oxide synthase (NOS) gene. In the intertidal copepod Tigriopus japonicus, we identified a NOS gene that is involved in immune responses of vertebrates and invertebrates. In silico analyses revealed that nitric oxide (NO) synthase domains, such as the oxygenase and reductase domains, are highly conserved in the T. japonicus NOS gene. The T. japonicus NOS gene was highly transcribed in the nauplii stages, implying that it plays a role in protecting the host during the early developmental stages. To examine the involvement of the T. japonicus NOS gene in the innate immune response, the copepods were exposed to lipopolysaccharide (LPS) and two Vibrio sp. After exposure to different concentrations of LPS and Vibrio sp., T. japonicus NOS transcription was significantly increased over time in a dose-dependent manner, and the NO/nitrite concentration increased as well. Taken together, our findings suggest that T. japonicus NOS transcription is induced in response to an immune challenge as part of the conserved innate immunity.
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identification of the retinoblastoma rb gene and expression in response to environmental stressors in the intertidal copepod Tigriopus japonicus
Marine Genomics, 2015Co-Authors: Bomi Kim, Changbum Jeong, Jaesung Rhee, Minchul Lee, Jae-seong LeeAbstract:There have been no reports thus far on the structure or molecular characterization of the retinoblastoma (Rb) gene of aquatic animals. Herein we describe the identification of the Rb gene of the intertidal copepod Tigriopus japonicus. In silico analyses revealed the conserved Rb domains of T. japonicus with those of protostomes. Phylogenetic analysis revealed that orthologs of Rb gene were evolved by an ancient split event in deuterostomes, while only a single Rb gene was conserved in protostomes except for Drosophila. The transcription of the T. japonicus Rb gene continuously increased across the molting transition from nauplius to the copepodid and adult stages, suggesting that it may play a developmental role in the molting process of T. japonicus. Information on Rb's response to environmental stressors, including toxin exposure, is lacking in copepods. To examine the transcriptional response to stressful conditions in laboratory culture conditions, copepods were exposed to UV-B radiation and different concentrations of metals, environmental toxins, and biocides. Transcription of the T. japonicus Rb gene was upregulated in response to about half of the 96 h-LD50 of UV-B radiation (12 kJ/m(2)) for 48 h, while the approximate 96 h-LD50 value (24 kJ/m(2)) of UV-B and relatively high concentrations of several toxins and biocides induced the downregulation of T. japonicus Rb mRNA expression. Taken together, our findings suggest that the T. japonicus Rb gene is sensitive to environmentally unfavorable conditions that can induce cell cycle alteration.
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genome wide identification and transcript profile of the whole cathepsin superfamily in the intertidal copepod Tigriopus japonicus
Developmental and Comparative Immunology, 2015Co-Authors: Changbum Jeong, Jae-seong Lee, Heum Gi Park, Bomi Kim, Hyeonjeong Choi, Inseon Baek, Sami Souissi, Jaesung RheeAbstract:Modulation of expression of cathepsins in innate immune response has previously been reported in mollusks and large crustaceans including crabs, lobsters, and shrimps in response to immune challenges. However, similar responses in copepods and the related cathepsin members remain under-investigated. To understand molecular and innate immune responses in the intertidal copepod Tigriopus japonicus, we identified the full spectra of cathepsin members (2 aspartyl proteases, 18 cysteine proteases, and 4 serine proteases) and also analyzed transcriptional expression of cathepsin (Tj-cathepsin) genes in developmental stages, lipopolysaccharide (LPS)- and two Vibrio species-exposed T. japonicus. The transcriptional levels of most Tj-cathepsin genes were highly increased during the molting transition from the nauplius to the copepodid stages. LPS treatment induced innate immune response via significant transcriptional increase of serine cathepsin (e.g., cathepsin As) members with induction of several cysteine cathepsin genes. However, Tj-aspartyl cathepsin E-like and a novel cysteine cathepsin were slightly reduced in response to LPS exposure. Interestingly, Vibrio species showed very low transcriptional sensitivity in the expression of entire cathepsins, while LPS induced several cathepsin gene-involved primitive immune responses in T. japonicus. In this paper, we discuss how whole cathepsin expression profiling can be linked to host defense mechanism to better understand and uncover the underlying mechanism of copepods' innate immunity.
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identification of insulin like peptide 1 ilp1 gene and its expression in response to different food sources in the intertidal copepod Tigriopus japonicus
Fisheries Science, 2015Co-Authors: Minchul Lee, Jaesung Rhee, Daesik Hwang, Jeonghoon Han, Hui-su Kim, Eunji Won, Seunghwi Lee, Jae-seong LeeAbstract:Insulin-like peptide (ILP) is an important hormone that controls a wide array of functions including glucose or trehalose levels in body fluids in invertebrates. However, the presence and role of ILP in copepods is unclear. To better understand the functional role of ILP in marine copepods, we isolated insulin-like peptide 1 (Tj-ILP1) from the copepod Tigriopus japonicus, characterized its conserved motifs, and measured its transcriptional modulation in response to different food sources. The open reading frame of Tj-ILP1 cDNA was 525 bp in length, encoding 174 amino acid residues. Multiple alignments revealed that six conserved cysteine residues in the ILP peptide domain were conserved for maintaining a tertiary structure. The Tj-ILP gene showed high expression levels in adult males, suggesting an association with sexual differentiation and male morphogenesis in T. japonicus. Additionally, to examine the role of Tj-ILP in dietary metabolism, we provided two food supplies (Chlorella vulgaris and Tetraselmis suecica) to copepods and measured dose- and time-dependent expression of Tj-ILP1 mRNA in response to different carbohydrate sources. Tj-ILP1 transcription activity was significantly elevated in response to both algal food supplies, indicating that the Tj-ILP1 gene is inducible with different food sources.
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β naphthoflavone induces oxidative stress in the intertidal copepod Tigriopus japonicus
Environmental Toxicology, 2015Co-Authors: Jaesung Rhee, Il-chan Kim, Young-mi Lee, Jae-seong Lee, Bomi Kim, Kenneth M.y. Leung, Joung Han YimAbstract:β-Naphtoflavone (β-NF) is a flavonoid and enhances oxidative stress in vertebrates with little information from aquatic invertebrates as yet. In this study, we investigated the effects of β-NF on the antioxidant defense systems of the intertidal copepod Tigriopus japonicus. To measure the β-NF-triggered changes in oxidative stress markers, such as intracellular reactive oxygen species (ROS), glutathione (GSH) concentration, residual glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR), and superoxide dismutase (SOD) activity, T. japonicus were exposed to β-NF (0.5 and 1 mg/L) for 72 h. Significant (P < 0.05) induction of the intracellular ROS content (%) was observed in 1 mg/L of β-NF exposed T. japonicus, compared to the negative control and H2O2-exposed group. The GSH levels were significantly increased in the 0.5 mg/L of β-NF-exposed group for 12 h and 1 mg/L of β-NF-exposed groups for 12–24 h. GPx, GST, and GR activities showed a significant increase in the 1 mg/L β-NF-exposed group, indicating that β-NF induces oxidative stress in T. japonicus. To understand the effects of β-NF at the level of transcript expression, a 6K microarray analysis was employed. Transcript profiles of selected antioxidant-related genes were modulated after 72 h exposure to 1 mg/L of β-NF. From microarray data, 10 GST isoforms, GR, GPx, PH-GPx, and Se-GPx were chosen for a time-course test by real-time RT-PCR. T. japonicus GST-S, GST-O, GST-M, and GST-D1 were significantly increased in a 1 mg/L β-NF-exposed group. T. japonicus GPx, GR, and Se-GPx mRNA levels were also significantly increased at both concentrations. Our results revealed that oxidative stress was induced by β-NF exposure in T. japonicus. © 2013 Wiley Periodicals, Inc. Environ Toxicol 30: 332–342, 2015.
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hydrophobic surface coating can reduce toxicity of zinc oxide nanoparticles to the marine copepod Tigriopus japonicus
Environmental Science & Technology, 2021Co-Authors: Hyemin Kang, Jae-seong Lee, Kenneth M.y. Leung, Guangjie Zhou, Racliffe Weng Seng Lai, Mana M N Yung, Aleksandra B DjurisicAbstract:Coated zinc oxide nanoparticles (ZnO-NPs) are more commonly applied in commercial products but current risk assessments mostly focus on bare ZnO-NPs. To investigate the impacts of surface coatings, this study examined acute and chronic toxicities of six chemicals, including bare ZnO-NPs, ZnO-NPs with three silane coatings of different hydrophobicity, zinc oxide bulk particles (ZnO-BKs), and zinc ions (Zn-IONs), toward a marine copepod, Tigriopus japonicus. In acute tests, bare ZnO-NPs and hydrophobic ZnO-NPs were less toxic than hydrophilic ZnO-NPs. Analyses of the copepod's antioxidant gene expression suggested that such differences were governed by hydrodynamic size and ion dissolution of the particles, which affected zinc bioaccumulation in copepods. Conversely, all test particles, except the least toxic hydrophobic ZnO-NPs, shared similar chronic toxicity as Zn-IONs because they mostly dissolved into zinc ions at low test concentrations. The metadata analysis, together with our test results, further suggested that the toxicity of coated metal-associated nanoparticles could be predicted by the hydrophobicity and density of their surface coatings. This study evidenced the influence of surface coatings on the physicochemical properties, toxicity, and toxic mechanisms of ZnO-NPs and provided insights into the toxicity prediction of coated nanoparticles from their coating properties to improve their future risk assessment and management.
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sunscreens containing zinc oxide nanoparticles can trigger oxidative stress and toxicity to the marine copepod Tigriopus japonicus
Marine Pollution Bulletin, 2020Co-Authors: Stella W Y Wong, Jae-seong Lee, Jeonghoon Han, Kevin W.h. Kwok, Kenneth M.y. Leung, Guangjie Zhou, Priscilla T Y LeungAbstract:Abstract The study, for the first time, evaluated the leaching rate of zinc oxide nanoparticles (nZnO) from human skins which were applied with three commercial sunscreens containing nZnO as an active ingredient. The leaching rate of nZnO varied greatly among the sunscreens, with a range of 8–72% (mean ± SD: 45% ± 33%). We further investigated their toxicities to the marine copepod Tigriopus japonicus. We found that 96-h median lethal concentrations of the three sunscreens to T. japonicus were > 5000, 230.6, and 43.0 mg chemical L−1, respectively, equivalent to Zn2+ concentrations at >82.5, 3.2, and 1.2 mg Zn L−1, respectively. Exposure to the individual sunscreens at environmentally realistic concentrations for 96 h led to up-regulation of antioxidant genes in T. japonicus, while they triggered the release of reactive oxygen species based on the results of in vivo assays. Evidently, these nZnO-included sunscreens can cause oxidative stress and hence pose risk to marine organisms.
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β naphthoflavone induces oxidative stress in the intertidal copepod Tigriopus japonicus
Environmental Toxicology, 2015Co-Authors: Jaesung Rhee, Il-chan Kim, Young-mi Lee, Jae-seong Lee, Bomi Kim, Kenneth M.y. Leung, Joung Han YimAbstract:β-Naphtoflavone (β-NF) is a flavonoid and enhances oxidative stress in vertebrates with little information from aquatic invertebrates as yet. In this study, we investigated the effects of β-NF on the antioxidant defense systems of the intertidal copepod Tigriopus japonicus. To measure the β-NF-triggered changes in oxidative stress markers, such as intracellular reactive oxygen species (ROS), glutathione (GSH) concentration, residual glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR), and superoxide dismutase (SOD) activity, T. japonicus were exposed to β-NF (0.5 and 1 mg/L) for 72 h. Significant (P < 0.05) induction of the intracellular ROS content (%) was observed in 1 mg/L of β-NF exposed T. japonicus, compared to the negative control and H2O2-exposed group. The GSH levels were significantly increased in the 0.5 mg/L of β-NF-exposed group for 12 h and 1 mg/L of β-NF-exposed groups for 12–24 h. GPx, GST, and GR activities showed a significant increase in the 1 mg/L β-NF-exposed group, indicating that β-NF induces oxidative stress in T. japonicus. To understand the effects of β-NF at the level of transcript expression, a 6K microarray analysis was employed. Transcript profiles of selected antioxidant-related genes were modulated after 72 h exposure to 1 mg/L of β-NF. From microarray data, 10 GST isoforms, GR, GPx, PH-GPx, and Se-GPx were chosen for a time-course test by real-time RT-PCR. T. japonicus GST-S, GST-O, GST-M, and GST-D1 were significantly increased in a 1 mg/L β-NF-exposed group. T. japonicus GPx, GR, and Se-GPx mRNA levels were also significantly increased at both concentrations. Our results revealed that oxidative stress was induced by β-NF exposure in T. japonicus. © 2013 Wiley Periodicals, Inc. Environ Toxicol 30: 332–342, 2015.
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functional characterization of p glycoprotein in the intertidal copepod Tigriopus japonicus and its potential role in remediating metal pollution
Aquatic Toxicology, 2014Co-Authors: Changbum Jeong, Heum Gi Park, Jaesung Rhee, Bomi Kim, Kenneth M.y. Leung, Sujae Lee, Kyunghoon Shin, Rae Kwon Kim, Jae-seong LeeAbstract:The intertidal copepod Tigriopus japonicus has been widely used in aquatic toxicity testing for diverse environmental pollutants including metals. Despite relatively well-characterized in vivo physiological modulations in response to aquatic pollutants, the molecular mechanisms due to toxicity and detoxification are still unclear. To better understand the mechanisms of metal transport and further detoxification, T. japonicus P-glycoprotein (TJ-P-gp) with conserved motifs/domains was cloned and measured for protein activity against the transcript and protein expression profiles in response to metal exposure. Specifically, we characterized the preliminary efflux activity and membrane topology of TJ-P-gp protein that supports a transport function for chemicals. To uncover whether the efflux activity of TJ-P-gp protein would be modulated by metal treatment, copepods were exposed to three metals (Cd, Cu, and Zn), and were observed for both dose- and time-dependency on the efflux activity of TJ-P-gp protein with or without 10μM of P-gp-specific inhibitors verapamil and zosuquidar (LY335979) for 24h over a wide range of metal concentrations. In particular, treatment with zosuquidar induced metal accumulation in the inner body of T. japonicus. In addition, three metals significantly induced the transporting activity of TJ-P-gp in a concentration-dependent manner in both transcript and protein levels within 24h. Together these data indicate that T. japonicus has a conserved P-gp-mediated metal defense system through the induction of transcriptional up-regulation of TJ-P-gp gene and TJ-P-gp protein activity. This finding provides further understanding of the molecular defense mechanisms involved in P-glycoprotein-mediated metal detoxification in copepods.
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ecotoxicity of triphenyltin on the marine copepod Tigriopus japonicus at various biological organisations from molecular to population level effects
Ecotoxicology, 2014Co-Authors: Jeonghoon Han, Jae-seong Lee, Kenneth M.y. LeungAbstract:Triphenyltin compounds (TPTs), as effective biocides for different industrial and agricultural purposes, have been detected in coastal marine environments worldwide, in particular in Asian countries. However, little is known about their toxicity to marine organisms. This study comprehensively investigated the molecular, individual and population responses of the marine copepod, Tigriopus japonicus upon waterborne exposure to TPT chloride (TPTCl). Our results indicated that TPTCl was highly toxic to adult T. japonicus, with a 96-h LC50 concentration at 6.3 μg/L. As shown in a chronic full life-cycle test, T. japonicus exposed to 1.0 μg/L TPTCl exhibited a delay in development and a significant reduction of population growth, in terms of the intrinsic rate of increase (r m ). Based on the negative relationship between the r m and exposure concentration, a critical effect concentration was estimated at 1.6 μg/L TPTCl; at or above which population extinction could occur. At 0.1 μg/L TPTCl or above, the sex ratio of the second generation of the copepod was significantly altered and changed to a male-biased population. At molecular level, the inhibition of the transcriptional expression of glutathione S-transferase related genes might lead to dysfunction of detoxification, and the inhibition of retinoid X receptor mRNA expression implied an interruption of the growth and moulting process in T. japonicus. As the only gene that observed up-regulated in this study, the expression of heat shock protein 70 (hsp70) increased in a concentration-dependent manner, indicating its function in protecting the copepod from TPT-mediated oxidative stress. The study advances our understanding on the ecotoxicity of TPT, and provides some initial data on its toxic mechanisms in small crustaceans like copepods.