scholarly journals Environmental chemical exposures in the urine of dogs and people sharing the same households

2020 ◽  
pp. 1-8
Author(s):  
Kaitlyn Craun ◽  
Kristofer Ross Luethcke ◽  
Martin Shafer ◽  
Noel Stanton ◽  
Chen Zhang ◽  
...  
Keyword(s):  
Dna Damage ◽  
Micronucleus Assay ◽  
Arsenic Species ◽  
Environmental Chemical ◽  
Mutagenic Potential ◽  
Pet Dogs ◽  
Healthy Humans ◽  
Monomethylarsonic Acid

Abstract Introduction: Urothelial carcinoma (UCC) develops in both humans and dogs and tracks to regions of high industrial activity. We hypothesize that dogs with UCC may act as sentinels for human urothelial carcinogen exposures. The aim of this pilot study was to determine whether healthy people and dogs in the same households share urinary exposures to potentially mutagenic chemical carcinogens. Methods: We measured urinary concentrations of acrolein (as its metabolite 3-HPMA), arsenic species, 4-aminobiphenyl, and 4-chlorophenol (a metabolite of the phenoxyherbicide 2,4-D) in healthy dogs and their owners. We assessed possible chemical sources through questionnaires and screened for urothelial DNA damage using the micronucleus assay. Results: Biomarkers of urinary exposure to acrolein, arsenic, and 4-chlorophenol were found in the urine of 42 pet dogs and 42 owners, with 4-aminobiphenyl detected sporadically. Creatinine-adjusted urinary chemical concentrations were significantly higher, by 2.8- to 6.2-fold, in dogs compared to humans. Correlations were found for 3-HPMA (r = 0.32, P = 0.04) and monomethylarsonic acid (r = 0.37, P = 0.02) between people and their dogs. Voided urothelial cell yields were inadequate to quantify DNA damage, and questionnaires did not reveal significant associations with urinary chemical concentrations. Conclusions: Healthy humans and pet dogs have shared urinary exposures to known mutagenic chemicals, with significantly higher levels in dogs. Higher urinary exposures to acrolein and arsenic in dogs correlate to higher exposures in their owners. Follow-up studies will assess the mutagenic potential of these levels in vitro and measure these biomarkers in owners of dogs with UCC.

scholarly journals Effect of High-Dose Topical Minoxidil on Erythrocyte Quality in SKH1 Hairless Mice

Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 731
Author(s):  
Eduardo Naranjo-Vázquez ◽  
María Guadalupe Sánchez-Parada ◽  
Belinda Claudia Gómez-Meda ◽  
Ana Lourdes Zamora-Perez ◽  
Martha Patricia Gallegos-Arreola ◽  
...  
Keyword(s):  
Dna Damage ◽  
Peripheral Blood ◽  
Micronucleus Assay ◽  
Control Group ◽  
High Dose ◽  
Entire Body ◽  
Hairless Mice ◽  
Mutagenic Potential ◽  
Polychromatic Erythrocytes ◽  
High Doses

SKH1 hairless mice are widely used in carcinogenesis and dermatology research due to their bare skin, as exposure to different agents is facilitated. Minoxidil is a cosmetic drug that is recognized as a mitogenic agent, and mitogens are suggested to have carcinogenic and mutagenic potential by inducing cell division and increasing the possibility of perpetuating DNA damage. Therefore, we hypothesized that the application of high doses of minoxidil to the skin of hairless mice would increase the number of micronucleated erythrocytes (MNEs) in peripheral blood. The objective of this study was to evaluate the topical administration of high doses of minoxidil on peripheral blood erythrocytes of SKH1 mice by means of micronucleus assay. Minoxidil was administered on the entire body surface of mice every 12 or 24 h. Minoxidil dosing every 24 h increased the number of micronucleated polychromatic erythrocytes (MNPCEs), and dosing every 12 h increased the number of MNEs and MNPCEs, as compared to baseline and the negative control group. No decrease in polychromatic erythrocyte frequencies was observed in the minoxidil groups. Therefore, topical application of high minoxidil doses to mice can produce DNA damage, as observed through an increase in the number of MNEs, without producing cytotoxicity, possibly due to its mitogenic effect.

scholarly journals Genotoxic Effect of Arsenate and Arsenite in Human HaCat Cells in Culture Using Comet Assay

2020 ◽  
pp. 36-44
Author(s):  
Ghazalla Benhusein ◽  
Elaine Mutch ◽  
Faith M. Williams
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Statistical Significance ◽  
Human Keratinocytes ◽  
Hacat Cells ◽  
Environmental Chemical ◽  
Viable Cells ◽  
Buthionine Sulphoximine ◽  
Ros Formation

Arsenic is an environmental chemical of toxicological concern today since it is a human genotoxin and chronic exposure is associated with development of cancers, including skin. Inorganic arsenate is metabolically reduced to arsenite by glutathione (GSH) prior to methylation. The aim of this study was to determine the relative toxic effects of arsenate and arsenite in HaCat cells (immortalized human keratinocytes) in vitro by measuring cytotoxicity, DNA damage, depletion of glutathione and apoptotic and necrotic events. HaCat cells were treated with arsenate and arsenite (10 μM) for DNA damage detection using Comet assay and cytotoxicity (10, 60 and 100 μM) all measured at 24 hr. In some experiment arsenate or arsenite (10 μM) was added at the same time as BSO 10 μM for 24 hr, and GSH levels were measured by HPLC with fluorescence detection. Flow cytometry was used to investigate apoptotic and necrotic events following arsenate and arsenite (10 μM) treatment for 24 hr. Arsenate and arsenite at 60 and 100 μM, but not 10 μM, reduced the number of adherent viable cells with time. Therefore, DNA damage could only be measured at 10 μM as at higher concentrations the cells did not produce classical Comets but showed fragmentation. DNA damage was significantly (p < 0.001) increased in cells treated for 24 hr with 10 μM arsenate and arsenite compared to control. GSH levels were significantly increased in HaCat cells treated with10 μM arsenate and arsenite (p < 0.05, p < 0.001, respectively) compared to control. Cells treated with buthionine sulphoximine (BSO) at the same time as arsenate had increased GSH levels (p < 0.001), but arsenite and BSO did not increase cellular GSH. Arsenate and arsenite increased apoptosis, and arsenate increased necrosis, although none of the values reached statistical significance. Arsenite was more cytotoxic than arsenate. Arsenate and arsenite are known to produce oxidative stress involving ROS formation and depletion of glutathione. The increase in GSH levels at low doses of arsenate and arsenite, and by arsenate even in the presence of BSO.

scholarly journals Genotoxicity and Cytotoxicity of Gold Nanoparticles In Vitro: Role of Surface Functionalization and Particle Size

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 271 ◽  
Author(s):  
Gerard Vales ◽  
Satu Suhonen ◽  
Kirsi M. Siivola ◽  
Kai M. Savolainen ◽  
Julia Catalán ◽  
...  
Keyword(s):  
Dna Damage ◽  
Gold Nanoparticles ◽  
Comet Assay ◽  
Positive Result ◽  
Cellular Uptake ◽  
Micronucleus Assay ◽  
Gold Nps ◽  
20 Nm

Several studies suggested that gold nanoparticles (NPs) could be genotoxic in vitro and in vivo. However, gold NPs have currently produced present a wide range of sizes and functionalization, which could affect their interactions with the environment or with biological structures and, thus, modify their toxic effects. In this study, we investigated the role of surface charge in determining the genotoxic potential of gold NPs, as measured by the induction of DNA damage (comet assay) and chromosomal damage (micronucleus assay) in human bronchial epithelial BEAS-2B cells. The cellular uptake of gold NPs was assessed by hyperspectral imaging. Two core sizes (~5 nm and ~20 nm) and three functionalizations representing negative (carboxylate), positive (ammonium), and neutral (poly(ethylene glycol); (PEG)ylated) surface charges were examined. Cationic ammonium gold NPs were clearly more cytotoxic than their anionic and neutral counterparts, but genotoxicity was not simply dependent on functionalization or size, since DNA damage was induced by 20-nm ammonium and PEGylated gold NPs, while micronucleus induction was increased by 5-nm ammonium and 20-nm PEGylated gold NPs. The 5-nm carboxylated gold NPs were not genotoxic, and evidence on the genotoxicity of the 20-nm carboxylated gold NPs was restricted to a positive result at the lowest dose in the micronucleus assay. When interpreting the results, it has to be taken into account that cytotoxicity limited the doses available for the ammonium-functionalized gold NPs and that gold NPs have earlier been described to interfere with the comet assay procedure, possibly resulting in a false positive result. In conclusion, our findings show that the cellular uptake and cytotoxicity of gold NPs are clearly enhanced by positive surface charge, but neither functionalization nor size can single-handedly account for the genotoxic effects of the gold NPs.

scholarly journals The Utility of a Novel Blood Based Biomarker in the Diagnosis of Pancreatic Cancer

2021 ◽  
Author(s):  
◽  
Lucy E. Nichols
Keyword(s):  
Pancreatic Cancer ◽  
Dna Damage ◽  
Human Peripheral Blood ◽  
Micronucleus Assay ◽  
Clinical Markers ◽  
Peripheral Blood Mononuclear ◽  
Markers Of Inflammation ◽  
Dismal Prognosis ◽  
Mutation Assay

Pancreatic cancer maintains one of the worst prognoses of all malignancies. Fewer than 1% of patients survive 10-years post-diagnosis. It is an aggressive disease with as many as 80% of patients diagnosed in the most advanced stages of disease. This severely limits treatment options, contributing to the dismal prognosis. Diagnosis remains a challenge. Often, imaging alone cannot differentiate between benign or malignant disease. Blood-based biomarker CA19-9 cannot be relied upon since it is a modified Lewis antigen so 5-10% of the population do not express it. Tissue biopsies remain the gold-standard for final confirmed diagnoses, yet collection of pancreatic biopsies is invasive, time and resource intensive and have a range of risks associated. Blood-based biomarkers offer a less invasive, cheaper, and more accessible alternative to more traditional diagnostic techniques. Here, we explored the use of novel DNA mutation assay, the human erythrocyte PIG-A assay, as a blood-based biomarker to determine whether it had any potential in diagnosing pancreatic cancer. An elevated frequency of PIG-A mutant erythrocytes was observed within pancreatic cancer patients in comparison to controls of healthy donors and a benign pancreatic disease cohort. Furthermore, the more well-established human peripheral blood mononuclear cell cytokinesis block micronucleus assay provided a secondary measure of DNA damage. An elevation was also viewed in this assay in malignant donors. Both assays were additionally explored within an in vitro setting, modelling the induction of DNA damage by known risk factors for pancreatic cancer. Given the complexity of pancreatic cancer diagnosis, a panel of biomarkers was explored, combining clinical markers of inflammation with our two DNA-based biomarkers and clinically approved CA19-9. Combination of the novel PIG-A mutation assay and CA19-9 blood-test appeared the most suitable panel of biomarkers for future exploration.

scholarly journals Phytochemical and In Vitro Genotoxicity Studies of Standardized Ficus deltoidea var. kunstleri Aqueous Extract

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 343
Author(s):  
Hussin Muhammad ◽  
Maizatul Hasyima Omar ◽  
Elda Nurafnie Ibnu Rasid ◽  
Shazlan Noor Suhaimi ◽  
Farah Huda Mohkiar ◽  
...  
Keyword(s):  
Dna Damage ◽  
Aqueous Extract ◽  
Micronucleus Assay ◽  
Coli Strain ◽  
In Vitro Assays ◽  
Metabolic System ◽  
Ficus Deltoidea ◽  
Mutation Assay ◽  
Negative Controls

The present study was carried out to assess the genotoxicity potential of Ficus deltoidea var. kunstleri aqueous extract (FDAE) using standard in vitro assays. The DNA damage of V79B cells was measured using the alkaline comet assay treated at 0.1 mg/mL (IC10) and 0.3 mg/mL (IC25) of FDAE together with positive and negative controls. For in vitro micronucleus assay, the V79B cells were treated with FDAE at five different concentrations (5, 2.5, 1.25, 0.625, and 0.3125 mg/mL) with and without S9 mixture. The bacteria reverse mutation assay of FDAE was performed on Salmonella typhimurium strains TA98, 100, 1535, 1537, and Escherichia coli strain WP2uvrA using pre-incubation method in the presence or in the absence of an extrinsic metabolic system (S9 mixture). FDAE at 0.1 and 0.3 mg/mL significantly increased DNA damage in both comet tail and tail moment (p < 0.05). No significant changes were detected in the number of micronucleated cell when compared to control. Tested at the doses up to 5000 µg/plate, the FDAE did not increase the number of revertant colonies for all strains. In conclusion, further investigation needs to be conducted in animal model to confirm the non-genotoxicity activities of FDAE.

scholarly journals Adaptation of the in vitro micronucleus assay for genotoxicity testing using 3D liver models supporting longer-term exposure durations

Mutagenesis ◽  
2020 ◽  
Vol 35 (4) ◽  
pp. 319-330 ◽  
Author(s):  
Gillian E Conway ◽  
Ume-Kulsoom Shah ◽  
Samantha Llewellyn ◽  
Tereza Cervena ◽  
Stephen J Evans ◽  
...  
Keyword(s):  
Dna Damage ◽  
3D Model ◽  
Low Dose ◽  
Micronucleus Assay ◽  
3D Models ◽  
Short Term ◽  
Cell Cycles ◽  
Genotoxic Chemicals ◽  
In Vitro Micronucleus Assay

Abstract Following advancements in the field of genotoxicology, it has become widely accepted that 3D models are not only more physiologically relevant but also have the capacity to elucidate more complex biological processes that standard 2D monocultures are unable to. Whilst 3D liver models have been developed to evaluate the short-term genotoxicity of chemicals, the aim of this study was to develop a 3D model that could be used with the regulatory accepted in vitro micronucleus (MN) following low-dose, longer-term (5 days) exposure to engineered nanomaterials (ENMs). A comparison study was carried out between advanced models generated from two commonly used liver cell lines, namely HepaRG and HepG2, in spheroid format. While both spheroid systems displayed good liver functionality and viability over 14 days, the HepaRG spheroids lacked the capacity to actively proliferate and, therefore, were considered unsuitable for use with the MN assay. This study further demonstrated the efficacy of the in vitro 3D HepG2 model to be used for short-term (24 h) exposures to genotoxic chemicals, aflatoxin B1 (AFB1) and methyl-methanesulfonate (MMS). The 3D HepG2 liver spheroids were shown to be more sensitive to DNA damage induced by AFB1 and MMS when compared to the HepG2 2D monoculture. This 3D model was further developed to allow for longer-term (5 day) ENM exposure. Four days after seeding, HepG2 spheroids were exposed to Zinc Oxide ENM (0–2 µg/ml) for 5 days and assessed using both the cytokinesis-block MN (CBMN) version of the MN assay and the mononuclear MN assay. Following a 5-day exposure, differences in MN frequency were observed between the CBMN and mononuclear MN assay, demonstrating that DNA damage induced within the first few cell cycles is distributed across the mononucleated cell population. Together, this study demonstrates the necessity to adapt the MN assay accordingly, to allow for the accurate assessment of genotoxicity following longer-term, low-dose ENM exposure.

Adaptation of the in vitro Micronucleus Assay (OECD 487) for the Assessment of the Mutagenic Potential of Nanoparticles

2021 ◽  
Vol 350 ◽  
pp. S154
Author(s):  
N. Honarvar ◽  
N. Partosa ◽  
C. Ulrich ◽  
C. Gomes ◽  
S. Berit-Seiffert ◽  
...  
Keyword(s):  
Micronucleus Assay ◽  
Mutagenic Potential ◽  
In Vitro Micronucleus Assay
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