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Earthworm coelomocytes as nanoscavenger of ZnO NPs.

Gupta S, Kushwah T, Yadav S - Nanoscale Res Lett (2014)

Bottom Line: They 'absorb' the dissolved chemicals through their moist 'body wall' due to the interstitial water and also ingest by 'mouth' while soil passes through the gut.Since the advent of the nanotechnology era, the environmental sink has been continuously receiving engineered nanomaterials as well as their derivatives.Our current understanding of the potential impact of nanomaterials and their natural scavenger is limited.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Zoology, School of Biological Sciences, Dr H S Gour Central University, Sagar, MP 470003, India.

ABSTRACT
Earthworms can 'biotransform' or 'biodegrade' chemical contaminants, rendering them harmless in their bodies, and can bioaccumulate them in their tissues. They 'absorb' the dissolved chemicals through their moist 'body wall' due to the interstitial water and also ingest by 'mouth' while soil passes through the gut. Since the advent of the nanotechnology era, the environmental sink has been continuously receiving engineered nanomaterials as well as their derivatives. Our current understanding of the potential impact of nanomaterials and their natural scavenger is limited. In the present investigation, we studied the cellular uptake of ZnO nanoparticles (NPs) by coelomocytes especially by chloragocytes of Eisenia fetida and their role as nanoscavenger. Results from exposure to 100- and 50-nm ZnO NPs indicate that coelomocytes of the earthworm E. fetida show no significant DNA damage at a dose lower than 3 mg/l and have the potential ability to uptake ZnO NPs from the soil ecosystem and transform them into microparticles.

No MeSH data available.


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Comet assay of coelomocytes after exposure to 100-nm ZnO NPs (5 mg/l) at different intervals.
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Figure 7: Comet assay of coelomocytes after exposure to 100-nm ZnO NPs (5 mg/l) at different intervals.

Mentions: Comet, tail DNA and Olive tail moment (OTM) were chosen to evaluate DNA damage in coelomocytes of E. fetida after exposure to 100- and 50-nm ZnO NPs at 1.0, 3.0 and 5.0 mg/l at different intervals (12, 24, 36 and 48 h). Results are shown in Table 1 and Figures 5, 6, 7 and 8. Coelomocytes exhibited DNA damage when exposed to 100-nm ZnO NPs at 36 and 48 h at the doses of 3.0 and 50 mg/l, while up to 24 h, there was no significant DNA damage. After exposure to 50-nm ZnO NPs at the dose of 3.0 mg/l, coelomocytes showed significant DNA damage at 40 h, and at 5.0 mg/l, significant Olive tail moment of comet was recorded at 36 and 48 h. However, no DNA damage was observed when the exposure dose was 1.0 mg/l for both 100- and 50-nm ZnO NPs. The results of the comet assay have shown clearly that the earthworm coelomocytes experienced DNA damage at exposure of more than 3 mg/l after 24 h. The study corroborates the finding of Bystrzejewska-Piotrowska et al. [38] who observed the capability of earthworms to extract zinc from soil exposed to ZnO nanoparticles. Cholewa et al. [18] demonstrated the capability of internalizing polymeric NPs (hydrodynamic diameter 45 ± 5 nm) by free circulating amoebocytes of the earthworm L. rubellus apparently involving an energy-dependent transport mechanism (clathrin and caveolin-mediated endocytosis pathways). Although NP uptake mechanisms are largely unknown in coelomocytes, uptake probably occurs by macropinocytosis [39]. In mammals, macropinocytosis initiates with cell membrane ruffling via actin rearrangement, suggesting an intriguing possibility of passive uptake of NPs that are membrane-adhered. Amongst invertebrates, ascidian haemocytes are able to engulf particles via RGD motif-dependent macropinocytosis [40]. However, such mechanisms are not yet known in earthworms. Another potential phagocytic pathway is via scavenger receptors that are expressed by both human macrophages and macrophage-like THP-1 cells [39]. Scavenger receptors are a conserved pattern known to bind lipids and polyanions for phagocytosis. In invertebrates, haemocytes from insects [41] and molluscs [42] are known to affect the scavenger receptor-mediated uptake of pathogens and apoptotic cells. To date, scavenger receptors are yet to be identified in earthworms; however, their ubiquitous presence suggests an unequivocally conserved role in innate immune recognition that may be involved in NP uptake as in the vertebrate counterpart. The coelomic fluid of earthworms is sometimes assumed, in the immunological context, to be equivalent to blood plasma in mammals, both representing a protein-rich immune-competent circulatory system. Distinct from the mammalian counterpart is the existence of chloragocytes involved in the regulation of essential minerals, haemoglobins and metallothioneins in response to natural stressors [43]. This is probably by functional analogy with the hepatic/renal systems of vertebrates, and chloragocytes may contribute to regulation of the total protein balance in coelomic fluid.


Earthworm coelomocytes as nanoscavenger of ZnO NPs.

Gupta S, Kushwah T, Yadav S - Nanoscale Res Lett (2014)

Comet assay of coelomocytes after exposure to 100-nm ZnO NPs (5 mg/l) at different intervals.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4060845&req=5

Figure 7: Comet assay of coelomocytes after exposure to 100-nm ZnO NPs (5 mg/l) at different intervals.
Mentions: Comet, tail DNA and Olive tail moment (OTM) were chosen to evaluate DNA damage in coelomocytes of E. fetida after exposure to 100- and 50-nm ZnO NPs at 1.0, 3.0 and 5.0 mg/l at different intervals (12, 24, 36 and 48 h). Results are shown in Table 1 and Figures 5, 6, 7 and 8. Coelomocytes exhibited DNA damage when exposed to 100-nm ZnO NPs at 36 and 48 h at the doses of 3.0 and 50 mg/l, while up to 24 h, there was no significant DNA damage. After exposure to 50-nm ZnO NPs at the dose of 3.0 mg/l, coelomocytes showed significant DNA damage at 40 h, and at 5.0 mg/l, significant Olive tail moment of comet was recorded at 36 and 48 h. However, no DNA damage was observed when the exposure dose was 1.0 mg/l for both 100- and 50-nm ZnO NPs. The results of the comet assay have shown clearly that the earthworm coelomocytes experienced DNA damage at exposure of more than 3 mg/l after 24 h. The study corroborates the finding of Bystrzejewska-Piotrowska et al. [38] who observed the capability of earthworms to extract zinc from soil exposed to ZnO nanoparticles. Cholewa et al. [18] demonstrated the capability of internalizing polymeric NPs (hydrodynamic diameter 45 ± 5 nm) by free circulating amoebocytes of the earthworm L. rubellus apparently involving an energy-dependent transport mechanism (clathrin and caveolin-mediated endocytosis pathways). Although NP uptake mechanisms are largely unknown in coelomocytes, uptake probably occurs by macropinocytosis [39]. In mammals, macropinocytosis initiates with cell membrane ruffling via actin rearrangement, suggesting an intriguing possibility of passive uptake of NPs that are membrane-adhered. Amongst invertebrates, ascidian haemocytes are able to engulf particles via RGD motif-dependent macropinocytosis [40]. However, such mechanisms are not yet known in earthworms. Another potential phagocytic pathway is via scavenger receptors that are expressed by both human macrophages and macrophage-like THP-1 cells [39]. Scavenger receptors are a conserved pattern known to bind lipids and polyanions for phagocytosis. In invertebrates, haemocytes from insects [41] and molluscs [42] are known to affect the scavenger receptor-mediated uptake of pathogens and apoptotic cells. To date, scavenger receptors are yet to be identified in earthworms; however, their ubiquitous presence suggests an unequivocally conserved role in innate immune recognition that may be involved in NP uptake as in the vertebrate counterpart. The coelomic fluid of earthworms is sometimes assumed, in the immunological context, to be equivalent to blood plasma in mammals, both representing a protein-rich immune-competent circulatory system. Distinct from the mammalian counterpart is the existence of chloragocytes involved in the regulation of essential minerals, haemoglobins and metallothioneins in response to natural stressors [43]. This is probably by functional analogy with the hepatic/renal systems of vertebrates, and chloragocytes may contribute to regulation of the total protein balance in coelomic fluid.

Bottom Line: They 'absorb' the dissolved chemicals through their moist 'body wall' due to the interstitial water and also ingest by 'mouth' while soil passes through the gut.Since the advent of the nanotechnology era, the environmental sink has been continuously receiving engineered nanomaterials as well as their derivatives.Our current understanding of the potential impact of nanomaterials and their natural scavenger is limited.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Zoology, School of Biological Sciences, Dr H S Gour Central University, Sagar, MP 470003, India.

ABSTRACT
Earthworms can 'biotransform' or 'biodegrade' chemical contaminants, rendering them harmless in their bodies, and can bioaccumulate them in their tissues. They 'absorb' the dissolved chemicals through their moist 'body wall' due to the interstitial water and also ingest by 'mouth' while soil passes through the gut. Since the advent of the nanotechnology era, the environmental sink has been continuously receiving engineered nanomaterials as well as their derivatives. Our current understanding of the potential impact of nanomaterials and their natural scavenger is limited. In the present investigation, we studied the cellular uptake of ZnO nanoparticles (NPs) by coelomocytes especially by chloragocytes of Eisenia fetida and their role as nanoscavenger. Results from exposure to 100- and 50-nm ZnO NPs indicate that coelomocytes of the earthworm E. fetida show no significant DNA damage at a dose lower than 3 mg/l and have the potential ability to uptake ZnO NPs from the soil ecosystem and transform them into microparticles.

No MeSH data available.


Related in: MedlinePlus