1
|
Chowdhury RR, Grosso MF, Gadara DC, Spáčil Z, Vidová V, Sovadinová I, Babica P. Cyanotoxin cylindrospermopsin disrupts lipid homeostasis and metabolism in a 3D in vitro model of the human liver. Chem Biol Interact 2024; 397:111046. [PMID: 38735451 DOI: 10.1016/j.cbi.2024.111046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 04/25/2024] [Accepted: 05/08/2024] [Indexed: 05/14/2024]
Abstract
Cylindrospermopsin, a potent hepatotoxin produced by harmful cyanobacterial blooms, poses environmental and human health concerns. We used a 3D human liver in vitro model based on spheroids of HepG2 cells, in combination with molecular and biochemical assays, automated imaging, targeted LC-MS-based proteomics, and lipidomics, to explore cylindrospermopsin effects on lipid metabolism and the processes implicated in hepatic steatosis. Cylindrospermopsin (1 μM, 48 h) did not significantly affect cell viability but partially reduced albumin secretion. However, it increased neutral lipid accumulation in HepG2 spheroids while decreasing phospholipid levels. Simultaneously, cylindrospermopsin upregulated genes for lipogenesis regulation (SREBF1) and triacylglycerol synthesis (DGAT1/2) and downregulated genes for fatty acid synthesis (ACLY, ACCA, FASN, SCD1). Fatty acid uptake, oxidation, and lipid efflux genes were not significantly affected. Targeted proteomics revealed increased levels of perilipin 2 (adipophilin), a major hepatocyte lipid droplet-associated protein. Lipid profiling quantified 246 lipid species in the spheroids, with 28 significantly enriched and 15 downregulated by cylindrospermopsin. Upregulated species included neutral lipids, sphingolipids (e.g., ceramides and dihexosylceramides), and some glycerophospholipids (phosphatidylethanolamines, phosphatidylserines), while phosphatidylcholines and phosphatidylinositols were mostly reduced. It suggests that cylindrospermopsin exposures might contribute to developing and progressing towards hepatic steatosis or metabolic dysfunction-associated steatotic liver disease (MASLD).
Collapse
|
2
|
Chowdhury RR, Rose S, Ezan F, Sovadinová I, Babica P, Langouët S. Hepatotoxicity of cyanotoxin microcystin-LR in human: Insights into mechanisms of action in the 3D culture model Hepoid-HepaRG. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 342:123047. [PMID: 38036087 DOI: 10.1016/j.envpol.2023.123047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 11/03/2023] [Accepted: 11/23/2023] [Indexed: 12/02/2023]
Abstract
Microcystin-LR (MC-LR) is a potent hepatotoxin produced by harmful cyanobacterial blooms (CyanoHABs). MC-LR targets highly differentiated hepatocytes expressing organic anion transporting polypeptides OATP1B1 and OATP1B3 that are responsible for hepatocellular uptake of the toxin. The present study utilized an advanced 3D in vitro human liver model Hepoid-HepaRG based on the cultivation of collagen-matrix embedded multicellular spheroids composed of highly differentiated and polarized hepatocyte-like cells. 14-d-old Hepoid-HepaRG cultures showed increased expression of OATP1B1/1B3 and sensitivity to MC-LR cytotoxicity at concentrations >10 nM (48 h exposure, EC20 = 26 nM). MC-LR induced neither caspase 3/7 activity nor expression of the endoplasmic reticulum stress marker gene BiP/GRP78, but increased release of pro-inflammatory cytokine IL-8, indicating a necrotic type of cell death. Subcytotoxic (10 nM) and cytotoxic (≥100 nM) MC-LR concentrations disrupted hepatocyte functions, such as xenobiotic metabolism phase-I enzyme activities (cytochrome P450 1A/1B) and albumin secretion, along with reduced expression of CYP1A2 and ALB genes. MC-LR also decreased expression of HNF4A gene, a critical regulator of hepatocyte differentiation and function. Genes encoding hepatobiliary membrane transporters (OATP1B1, BSEP, NTCP), hepatocyte gap junctional gene connexin 32 and the epithelial cell marker E-cadherin were also downregulated. Simultaneous upregulation of connexin 43 gene, primarily expressed by liver progenitor and non-parenchymal cells, indicated a disruption of tissue homeostasis. This was associated with a shift in the expression ratio of E-cadherin to N-cadherin towards the mesenchymal cell marker, a process linked to epithelial-mesenchymal transition (EMT) and hepatocarcinogenesis. The effects observed in the human liver cell in vitro model revealed mechanisms that can potentially contribute to the MC-LR-induced promotion and progression of hepatocellular carcinoma (HCC). Hepoid-HepaRG cultures provide a robust, accessible and versatile in vitro model, capable of sensitively detecting hepatotoxic effects at toxicologically relevant concentrations, allowing for assessing hepatotoxicity mechanisms, human health hazards and impacts of environmental hepatotoxins, such as MC-LR.
Collapse
|
3
|
Skočková V, Raptová P, Pospíchalová K, Sovadinová I, Sychrová E, Smutná M, Hilscherová K, Babica P, Šindlerová L. Cyanobacterial harmful bloom lipopolysaccharides: pro-inflammatory effects on epithelial and immune cells in vitro. Arch Toxicol 2024; 98:481-491. [PMID: 38063875 PMCID: PMC10794361 DOI: 10.1007/s00204-023-03644-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 11/16/2023] [Indexed: 01/18/2024]
Abstract
Cyanobacterial harmful blooms (CyanoHABs) pose a global ecological problem, and their lipopolysaccharides (LPS) are among the bioactive compounds they release. Previous studies on CyanoHAB-LPS from single cyanobacterial species have shown varying bioactivities in different in vitro cell models. In this study, we isolated LPS from 19 CyanoHAB samples collected at 18 water bodies in the Czech Republic over two consecutive seasons. The proportions of cyanobacteria, Gram-negative bacteria (G-), and other bacteria in the biomass were determined by qPCR, while the cyanobacterial genera were identified using light microscopy. In vitro models of keratinocytes (HaCaT), the intestinal epithelium (co-culture of differentiated Caco-2 cells and peripheral blood mononuclear cells - PBMC), and PBMC alone were treated with isolated LPS at concentrations of 50, 100, and 1 µg/ml, respectively. The endotoxin activities of these concentrations were within the range measured in the aquatic environment. Approximately 85-90% of the samples displayed biological activity. However, the potency of individual LPS effects and response patterns varied across the different in vitro models. Furthermore, the observed activities did not exhibit a clear correlation with the taxonomic composition of the phytoplankton community, the relative share of microbial groups in the biomass, endotoxin activity of the LPS, or LPS migration and staining pattern in SDS-PAGE. These findings suggest that the effects of CyanoHAB-LPS depend on the specific composition and abundance of various LPS structures within the complex environmental sample and their interactions with cellular receptors.
Collapse
|
4
|
Raptová P, Skočková V, Babica P, Sovadinová I, Sychrová E, Vídeňská P, Šplíchalová P, Vašíček O, Šindlerová L. Cyanobacterial bloom-associated lipopolysaccharides induce pro-inflammatory processes in keratinocytes in vitro. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2024; 105:104342. [PMID: 38092246 DOI: 10.1016/j.etap.2023.104342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 10/23/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023]
Abstract
Our previous studies have shown that CyanoHAB LPS (lipopolysaccharides) and LPS from cyanobacterial cultures induce pro-inflammatory effects on intestinal epithelial and immune cells in vitro. To expand our understanding, we investigated their impact on human keratinocytes, which are targeted during water recreational activities. LPS samples were isolated from CyanoHAB biomasses dominated by Microcystis, Aphanizomenon, Planktothrix, and Dolichospermum, or from axenic cultures of these genera. We identified two CyanoHAB biomasses containing a high proportion of Gram-negative bacteria, including potentially pathogenic genera. These biomasses showed the highest induction of interleukin (IL) 8, IL-6, C-C motif chemokine ligand (CCL) 2 (also known as MCP-1), and CCL20 production by HaCaT cells. Interestingly, all CyanoHAB-derived LPS and LPS from axenic cultures (except for Microcystis) accelerated cell proliferation and migration. Our findings highlight the role of G- bacteria composition and LPS structural disparities in influencing these effects, with implications for skin health during recreational activities.
Collapse
|
5
|
Bajard L, Vespalcová H, Negi CK, Kohoutek J, Bláha L, Sovadinová I. Anti-androgenic activity of novel flame retardants in mixtures: Newly identified contribution from tris(2,3-dibromopropyl) isocyanurate (TDBP-TAZTO). CHEMOSPHERE 2023; 341:140004. [PMID: 37652251 DOI: 10.1016/j.chemosphere.2023.140004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 08/23/2023] [Accepted: 08/26/2023] [Indexed: 09/02/2023]
Abstract
In recent decades, male infertility has been on the rise, largely attributed to exposure to chemicals with endocrine-disrupting properties. The adverse effects of disrupting androgen actions on the development and reproductive health of children and adolescents have been extensively studied. Flame retardants (FRs), used in consumer products to delay flammability, have been identified as antagonists of the androgen receptor (AR), potentially leading to adverse outcomes in male reproductive health later in life. This study examined the interaction of eight novel FRs with the AR, employing an in vitro AR-dependent luciferase reporter gene assay utilizing MDA-kb2 cells. The investigation revealed the anti-androgenic activity of tris(2,3-dibromopropyl) isocyanurate (TDBP-TAZTO), a frequently detected FR in the environment. Furthermore, TDBP-TAZTO contributed to anti-androgenic activity when combined with six other anti-androgenic FRs. The mixture effects were predicted by three commonly employed models: concentration addition (CA), generalized CA, and independent action, with the CA model showcasing the highest accuracy. This suggests that all FRs act through a similar mechanism, as further confirmed by in silico molecular docking, indicating limited synergy or antagonism. Importantly, in the mixtures, each FR contributed to the induction of anti-androgenic effects at concentrations below their individual effective concentrations in single exposures. This raises concern for public health, especially considering the co-detection of these FRs and their potential co-occurrence with other anti-androgenic chemicals like bisphenols. Therefore, our findings, along with previous research, strongly support the incorporation of combined effects of mixtures in risk assessment to efficiently safeguard population health.
Collapse
|
6
|
Audebert M, Assmann AS, Azqueta A, Babica P, Benfenati E, Bortoli S, Bouwman P, Braeuning A, Burgdorf T, Coumoul X, Debizet K, Dusinska M, Ertych N, Fahrer J, Fetz V, Le Hégarat L, López de Cerain A, Heusinkveld HJ, Hogeveen K, Jacobs MN, Luijten M, Raitano G, Recoules C, Rundén-Pran E, Saleh M, Sovadinová I, Stampar M, Thibol L, Tomkiewicz C, Vettorazzi A, Van de Water B, El Yamani N, Zegura B, Oelgeschläger M. New approach methodologies to facilitate and improve the hazard assessment of non-genotoxic carcinogens-a PARC project. FRONTIERS IN TOXICOLOGY 2023; 5:1220998. [PMID: 37492623 PMCID: PMC10364052 DOI: 10.3389/ftox.2023.1220998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 06/19/2023] [Indexed: 07/27/2023] Open
Abstract
Carcinogenic chemicals, or their metabolites, can be classified as genotoxic or non-genotoxic carcinogens (NGTxCs). Genotoxic compounds induce DNA damage, which can be detected by an established in vitro and in vivo battery of genotoxicity assays. For NGTxCs, DNA is not the primary target, and the possible modes of action (MoA) of NGTxCs are much more diverse than those of genotoxic compounds, and there is no specific in vitro assay for detecting NGTxCs. Therefore, the evaluation of the carcinogenic potential is still dependent on long-term studies in rodents. This 2-year bioassay, mainly applied for testing agrochemicals and pharmaceuticals, is time-consuming, costly and requires very high numbers of animals. More importantly, its relevance for human risk assessment is questionable due to the limited predictivity for human cancer risk, especially with regard to NGTxCs. Thus, there is an urgent need for a transition to new approach methodologies (NAMs), integrating human-relevant in vitro assays and in silico tools that better exploit the current knowledge of the multiple processes involved in carcinogenesis into a modern safety assessment toolbox. Here, we describe an integrative project that aims to use a variety of novel approaches to detect the carcinogenic potential of NGTxCs based on different mechanisms and pathways involved in carcinogenesis. The aim of this project is to contribute suitable assays for the safety assessment toolbox for an efficient and improved, internationally recognized hazard assessment of NGTxCs, and ultimately to contribute to reliable mechanism-based next-generation risk assessment for chemical carcinogens.
Collapse
|
7
|
Součková K, Jasík M, Sovadinová I, Sember A, Sychrová E, Konieczna A, Bystrý V, Dyková I, Blažek R, Lukšíková K, Pavlica T, Jankásek M, Altmanová M, Žák J, Zbončáková A, Reichard M, Slabý O. From fish to cells: Establishment of continuous cell lines from embryos of annual killifish Nothobranchius furzeri and N. kadleci. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2023; 259:106517. [PMID: 37087860 DOI: 10.1016/j.aquatox.2023.106517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/24/2023] [Accepted: 03/30/2023] [Indexed: 05/03/2023]
Abstract
There is a growing need of alternative experimental models that avoid or minimize the use of animals due to ethical, economical, and scientific reasons. Surprisingly, the stable embryonic cell lines representing Nothobranchius spp., emerging vertebrate models in aging research, regenerative medicine, ecotoxicology, or genomics, have been not derived so far. This paper reports establishment and deep characterization of ten continuous cell lines from annual killifish embryos of N. furzeri and N. kadleci. The established cell lines exhibited mostly fibroblast- and epithelial-like morphology and steady growth rates with cell doubling time ranging from 27 to 40 h. All cell lines retained very similar characteristics even after continuous subcultivation (more than 100 passages) and extended storage in liquid nitrogen (∼3 years). The cytogenetic analysis of the cell lines revealed a diploid chromosome number mostly equal to 38 elements (i.e., the native chromosome count for both killifish species), with minor but diverse line/passage-specific karyotype changes compared to the patterns observed in non-cultured N. furzeri and N. kadleci somatic cells. Based on transcriptional analysis of marker genes, the cell lines displayed features of an undifferentiated state without signs of senescence even in advanced passages. We confirmed that the cell lines are transfectable and can form viable 3-D spheroids. The applicability of the cell lines for (eco)toxicological surveys was confirmed by assessing the effect of cytotoxic and growth inhibitory agents. Properties of established Nothobranchius embryonic cell lines open new possibilities for the application of this model in various fields of life sciences including molecular mechanisms of aging, karyotype (in)stability or differences in lifespan.
Collapse
|
8
|
Labohá P, Sychrová E, Brózman O, Sovadinová I, Bláhová L, Prokeš R, Ondráček J, Babica P. Cyanobacteria, cyanotoxins and lipopolysaccharides in aerosols from inland freshwater bodies and their effects on human bronchial cells. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2023; 98:104073. [PMID: 36738853 DOI: 10.1016/j.etap.2023.104073] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 01/19/2023] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
Components of cyanobacterial water blooms were quantified in aerosols above agitated water surfaces of five freshwater bodies. The thoracic and respirable aerosol fraction (0.1-10 µm) was sampled using a high-volume sampler. Cyanotoxins microcystins were detected by LC-MS/MS at levels 0.3-13.5 ng/mL (water) and < 35-415 fg/m3 (aerosol). Lipopolysaccharides (endotoxins) were quantified by Pyrogene rFC assay at levels < 10-119 EU/mL (water) and 0.13-0.64 EU/m3 (aerosol). Cyanobacterial DNA was detected by qPCR at concentrations corresponding to 104-105 cells eq./mL (water) and 101-103 cells eq./m3 (aerosol). Lipopolysaccharides isolated from bloom samples induced IL-6 and IL-8 cytokine release in human bronchial epithelial cells Beas-2B, while extracted cyanobacterial metabolites induced both pro-inflammatory and cytotoxic effects. Bloom components detected in aerosols and their bioactivities observed in upper respiratory airway epithelial cells together indicate that aerosols formed during cyanobacterial water blooms could induce respiratory irritation and inflammatory injuries, and thus present an inhalation health risk.
Collapse
|
9
|
Sychrová E, Yawer A, Labohá P, Basu A, Dydowiczová A, Virmani I, Babica P, Sovadinová I. In vitro testicular toxicity of environmentally relevant endocrine-disrupting chemicals: 2D vs. 3D models of prepubertal Leydig TM3 cells. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2022; 93:103869. [PMID: 35550872 DOI: 10.1016/j.etap.2022.103869] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 03/22/2022] [Accepted: 04/26/2022] [Indexed: 06/15/2023]
Abstract
The testis is a priority organ for developing alternative models to assess male reproductive health hazards of chemicals. This study characterized a 3D in vitro model of murine prepubertal Leydig TM3 cells with improved expression of steroidogenesis markers suitable for image-based screening of testicular toxicity. This 3D scaffold-free spheroid model was applied to explore the impact of prototypical endocrine-disrupting chemicals (EDCs) and environmental reprotoxicants (benzo[a]pyrene, 2- and 9-methylanthracenes, fluoranthene, triclosan, triclocarban, methoxychlor) on male reproductive health. The results were compared to the male reprotoxicity potential of EDCs assessed in a traditional monolayer (2D) culture. The testicular toxicity was dependent not only on the type of culture (2D vs. 3D models) but also on the duration of exposure. Benzo[a]pyrene and triclocarban were the most active compounds, eliciting cytotoxic effects in prepubertal Leydig cells at low micromolar concentrations, which might be a mechanism contributing to their male reprotoxicity.
Collapse
|
10
|
Yawer A, Sychrová E, Raška J, Babica P, Sovadinová I. Endocrine-disrupting chemicals affect sertoli TM4 cell functionality through dysregulation of gap junctional intercellular communication in vitro. Food Chem Toxicol 2022; 164:113004. [PMID: 35413382 DOI: 10.1016/j.fct.2022.113004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/20/2022] [Accepted: 04/06/2022] [Indexed: 01/10/2023]
Abstract
The frequencies of adverse outcomes associated with male reproductive health, including infertility and testicular cancer, are increasing. These adverse trends are partially attributed to increased exposure to environmental agents such as endocrine-disrupting chemicals (EDCs). This study addresses effects on EDCs on adjacent prepubertal Sertoli TM4 cells, specifically on 1) testicular gap junctional intercellular communication (GJIC), one of the hallmarks of non-genotoxic carcinogenicity, 2) GJIC building blocks connexins (Cx), and 3) mitogen-activated protein kinases MAPKs. We selected eight representatives of EDCs: bisphenol A and organochlorine chemicals such as pesticides dichlorodiphenyltrichloroethane, lindane, methoxychlor, and vinclozolin, industrial chemical 2,2',4,4',5,5'-hexachlorobiphenyl, and components of personal care products, triclocarban and triclosan. EDCs rapidly dysregulated GJIC in Sertoli TM4 cells mainly via MAPK p38 and/or Erk1/2/pathways by the intermediate hyper- or de-phosphorylation of Cx43 (Ser368, Ser282) and translocalization of Cx43 from the plasma membrane, suggesting disturbed intracellular trafficking of Cx43 protein. Surprisingly, EDCs did not rapidly activate MAPK Erk1/2 or p38; on the contrary, TCC and TCS decreased their activity (phosphorylation). Our results indicate that EDCs might disrupt testicular homeostasis and development via testicular GJIC, junctional and non-junctional functions of Cx43 and MAPK-signalling pathways in Sertoli cells.
Collapse
|
11
|
Mikula P, Mlnaříková M, Nadres ET, Takahashi H, Babica P, Kuroda K, Bláha L, Sovadinová I. Synthetic Biomimetic Polymethacrylates: Promising Platform for the Design of Anti-Cyanobacterial and Anti-Algal Agents. Polymers (Basel) 2021; 13:polym13071025. [PMID: 33810255 PMCID: PMC8036423 DOI: 10.3390/polym13071025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/20/2021] [Accepted: 03/23/2021] [Indexed: 01/26/2023] Open
Abstract
Extensive, uncontrolled growth of algae and cyanobacteria is an environmental, public health, economic, and technical issue in managing natural and engineered water systems. Synthetic biomimetic polymers have been almost exclusively considered antimicrobial alternatives to conventional antibiotics to treat human bacterial infections. Very little is known about their applicability in an aquatic environment. Here, we introduce synthetic biomimetic polymethacrylates (SBPs) as a cost-effective and chemically facile, flexible platform for designing a new type of agent suitable for controlling and mitigating photosynthetic microorganisms. Since SBPs are cationic and membranolytic in heterotrophic bacteria, we hypothesized they could also interact with negatively charged cyanobacterial or algal cell walls and membranes. We demonstrated that SBPs inhibited the growth of aquatic photosynthetic organisms of concern, i.e., cyanobacteria (Microcystis aeruginosa and Synechococcus elongatus) and green algae (Chlamydomonas reinhardtii and Desmodesmus quadricauda), with 50% effective growth-inhibiting concentrations ranging between 95 nM and 6.5 μM. Additionally, SBPs exhibited algicidal effects on C. reinhardtii and cyanocidal effects on picocyanobacterium S. elongatus and microcystin-producing cyanobacterium M. aeruginosa. SBP copolymers, particularly those with moderate hydrophobic content, induced more potent cyanostatic and cyanocidal effects than homopolymers. Thus, biomimetic polymers are a promising platform for the design of anti-cyanobacterial and anti-algal agents for water treatment.
Collapse
|
12
|
Yawer A, Sychrová E, Labohá P, Raška J, Jambor T, Babica P, Sovadinová I. Endocrine-disrupting chemicals rapidly affect intercellular signaling in Leydig cells. Toxicol Appl Pharmacol 2020; 404:115177. [PMID: 32739526 DOI: 10.1016/j.taap.2020.115177] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/19/2020] [Accepted: 07/28/2020] [Indexed: 01/25/2023]
Abstract
A decline in male fertility possibly caused by environmental contaminants, namely endocrine-disrupting chemicals (EDCs), is a topic of public concern and scientific interest. This study addresses a specific role of testicular gap junctional intercellular communication (GJIC) between adjacent prepubertal Leydig cells in endocrine disruption and male reproductive toxicity. Organochlorine pesticides (lindane, methoxychlor, DDT), industrial chemicals (PCB153, bisphenol A, nonylphenol and octylphenol) as well as personal care product components (triclosan, triclocarban) rapidly dysregulated GJIC in murine Leydig TM3 cells. The selected GJIC-inhibiting EDCs (methoxychlor, triclosan, triclocarban, lindane, DDT) caused the immediate GJIC disruption by the relocation of gap junctional protein connexin 43 (Cx43) from the plasma membrane and the alternation of Cx43 phosphorylation pattern (Ser368, Ser279, Ser282) of its full-length and two N-truncated isoforms. After more prolonged exposure (24 h), EDCs decreased steady-state levels of full-length Cx43 protein and its two N-truncated isoforms, and eventually (triclosan, triclocarban) also tight junction protein Tjp-1. The disturbance of GJIC was accompanied by altered activity of mitogen-activated protein kinases MAPK-Erk1/2 and MAPK-p38, and a decrease in stimulated progesterone production. Our results indicate that EDCs might disrupt testicular homeostasis and development via disruption of testicular GJIC, a dysregulation of junctional and non-junctional functions of Cx43, activation of MAPKs, and disruption of an early stage of steroidogenesis in prepubertal Leydig cells. These critical disturbances of Leydig cell development and functions during a prepubertal period might be contributing to impaired male reproduction health later on.
Collapse
|
13
|
Dydowiczová A, Brózman O, Babica P, Sovadinová I. Improved multiparametric scrape loading-dye transfer assay for a simultaneous high-throughput analysis of gap junctional intercellular communication, cell density and viability. Sci Rep 2020; 10:730. [PMID: 31959888 PMCID: PMC6971000 DOI: 10.1038/s41598-020-57536-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 12/31/2019] [Indexed: 12/28/2022] Open
Abstract
Gap junctional intercellular communication (GJIC) is a vital cellular process required for maintenance of tissue homeostasis. In vitro assessment of GJIC represents valuable phenotypic endpoint that could be effectively utilized as an integral component in modern toxicity testing, drug screening or biomedical in vitro research. However, currently available methods for quantifying GJIC with higher-throughputs typically require specialized equipment, proprietary software and/or genetically engineered cell models. To overcome these limitations, we present here an innovative adaptation of traditional, fluorescence microscopy-based scrape loading-dye transfer (SL-DT) assay, which has been optimized to simultaneously evaluate GJIC, cell density and viability. This multiparametric method was demonstrated to be suitable for various multiwell microplate formats, which facilitates an automatized image acquisition. The assay workflow is further assisted by an open source-based software tools for batch image processing, analysis and evaluation of GJIC, cell density and viability. Our results suggest that this approach provides a simple, fast, versatile and cost effective way for in vitro high-throughput assessment of GJIC and other related phenotypic cellular events, which could be included into in vitro screening and assessment of pharmacologically and toxicologically relevant compounds.
Collapse
|
14
|
Raška J, Čtveráčková L, Dydowiczová A, Sovadinová I, Bláha L, Babica P. Cylindrospermopsin induces cellular stress and activation of ERK1/2 and p38 MAPK pathways in adult human liver stem cells. CHEMOSPHERE 2019; 227:43-52. [PMID: 30981969 DOI: 10.1016/j.chemosphere.2019.03.131] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 03/16/2019] [Accepted: 03/19/2019] [Indexed: 06/09/2023]
Abstract
Cyanobacterial toxin cylindrospermopsin (CYN) is an emerging freshwater contaminant, whose expanding environmental occurrence might result into increased human health risks. CYN is potent hepatotoxin, with cytotoxicity and genotoxicity documented in primary hepatocytes or hepatoma cell lines. However, there is only limited information about CYN effects on adult human liver stem cells (LSCs), which play an important role in liver tissue development, regeneration and repair. In our study with human liver cell line HL1-hT1 which expresses characteristics of LSCs, CYN was found to be cytotoxic and increasing cell death after 24-48 h exposure to concentrations >1 μM. Subcytotoxic 1 μM concentration did not induce cell death or membrane damage, but inhibited cellular processes related to energy production, leading to a growth stagnation after >72 h. Interestingly, these effects were not associated with increased DNA damage, reactive oxygen species production, or endoplasmic reticulum stress. However, CYN induced a sustained (24-48 h) activation of mitogen-activated protein kinases ERK1/2 and p38, and increased expression of stress-related transcription factor ATF3. Thus, LSCs were not primarily affected by CYN-induced genotoxicity and oxidative stress, but via activation of signaling and transcriptional pathways critical for regulation of cell proliferation, stress responses, cell survival and inflammation. Alterations of LSCs during CYN-induced liver injury, including the role of nongenotoxic mechanisms, should be therefore considered in mechanistic assessments of chronic CYN hepatotoxicity and hepatocarcinogenicity.
Collapse
|
15
|
Kubincová P, Sychrová E, Raška J, Basu A, Yawer A, Dydowiczová A, Babica P, Sovadinová I. Polycyclic Aromatic Hydrocarbons and Endocrine Disruption: Role of Testicular Gap Junctional Intercellular Communication and Connexins. Toxicol Sci 2019; 169:70-83. [DOI: 10.1093/toxsci/kfz023] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Abstract
Ambient air pollution and smoking are well-documented risk factors for male infertility. Prevalent air pollutants and cigarette smoke components, polycyclic aromatic hydrocarbons (PAHs), are environmental and occupational toxicants that act as chemicals disrupting endocrine regulation and reproductive potential in males. Testicular gap junctional intercellular communication (GJIC) is critical for normal development and function of testicular tissue, thus we assessed GJIC as a process potentially targeted by PAHs in testes. Lower MW PAHs with a bay or bay-like region rapidly dysregulated GJIC in Leydig TM3 cells by relocalization of major testicular gap junctional protein connexin 43 (Cx43) from plasma membrane to cytoplasm. This was associated with colocalization between Cx43 and ubiquitin in intracellular compartments, but without any effect on Cx43 degradation rate or steady-state Cx43 mRNA levels. A longer exposure to active PAHs decreased steady-state levels of full-length Cx43 protein and its 2 N-truncated isoforms. Inhibition of GJIC by PAHs, similarly to a prototypic GJIC-inhibitor TPA, was mediated via the MAP kinase-Erk1/2 and PKC pathways. Polycyclic aromatic hydrocarbon-induced GJIC dysregulation in testes was cell-type-specific because neither PAH dysregulated GJIC in Sertoli TM4 cells, despite PAHs were rapidly taken up by both Leydig TM3 as well as Sertoli TM4 cells. Because TPA effectively dysregulated GJIC in both testicular cell types, a unique regulator of GJIC targeted by PAHs might exist in Leydig TM3 cells. Our results indicate that PAHs could be a potential etiological agent contributing to reproductive dysfunctions in males through an impairment of testicular GJIC and junctional and/or nonjunctional functions of Cx43.
Collapse
|
16
|
Upham BL, Sovadinová I, Babica P. Gap Junctional Intercellular Communication: A Functional Biomarker to Assess Adverse Effects of Toxicants and Toxins, and Health Benefits of Natural Products. J Vis Exp 2016:54281. [PMID: 28060274 PMCID: PMC5226465 DOI: 10.3791/54281] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
This protocol describes a scalpel loading-fluorescent dye transfer (SL-DT) technique that measures intercellular communication through gap junction channels, which is a major intercellular process by which tissue homeostasis is maintained. Interruption of gap junctional intercellular communication (GJIC) by toxicants, toxins, drugs, etc. has been linked to numerous adverse health effects. Many genetic-based human diseases have been linked to mutations in gap junction genes. The SL-DT technique is a simple functional assay for the simultaneous assessment of GJIC in a large population of cells. The assay involves pre-loading cells with a fluorescent dye by briefly perturbing the cell membrane with a scalpel blade through a population of cells. The fluorescent dye is then allowed to traverse through gap junction channels to neighboring cells for a designated time. The assay is then terminated by the addition of formalin to the cells. The spread of the fluorescent dye through a population of cells is assessed with an epifluorescence microscope and the images are analyzed with any number of morphometric software packages that are available, including free software packages found on the public domain. This assay has also been adapted for in vivo studies using tissue slices from various organs from treated animals. Overall, the SL-DT assay can serve a broad range of in vitro pharmacological and toxicological needs, and can be potentially adapted for high throughput set-up systems with automated fluorescence microscopy imaging and analysis to elucidate more samples in a shorter time.
Collapse
|
17
|
Abstract
The scrape loading/dye transfer (SL/DT) technique is a simple functional assay for the simultaneous assessment of gap junctional intercellular communication (GJIC) in a large population of cells. The equipment needs are minimal and are typically met in standard cell biology labs, and SL/DT is the simplest and quickest of all the assays that measure GJIC. This assay has also been adapted for in vivo studies. The SL/DT assay is also conducive to a high-throughput setup with automated fluorescence microscopy imaging and analysis to elucidate more samples in shorter time, and hence can serve a broad range of in vitro pharmacological and toxicological needs.
Collapse
|
18
|
Dvorák Z, Sovadinová I, Bláha L, Giesy JP, Ulrichová J. Quaternary benzo[c]phenathridine alkaloids sanguinarine and chelerythrine do not affect transcriptional activity of aryl hydrocarbon receptor: Analyses in rat hepatoma cell line H4IIE.luc. Food Chem Toxicol 2006; 44:1466-73. [PMID: 16782256 DOI: 10.1016/j.fct.2006.04.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2005] [Revised: 03/02/2006] [Accepted: 04/27/2006] [Indexed: 10/24/2022]
Abstract
Quaternary benzo[c]phenanthridine alkaloids (QBAs) sanguinarine and chelerythrine exert a plethora of biological activities. Nevertheless, the specific cellular target for these alkaloids within the cell was not identified as far. Several literary data indicate that biological effects of QBAs could be associated with aryl hydrocarbon receptor (AhR) signaling pathway, including cytochrome P450 CYP1A, however, available information are controversial. In this work we analyzed the effects of sanguinarine and chelerythrine on AhR activity in rat hepatoma cells HII4E.luc stably transfected with dioxin responsive element fused to luciferase gene (DRE-LUC). Studied QBAs were tested in submicromolar concentration range (0.0001-1 microM) and in incubation times 6, 24 and 48 h. Transcriptional activity of AhR was monitored by chemiluminiscence measurement of luciferase catalytic activity. Sanguinarine and chelerythrine did not activated AhR in any time or dose tested. Chelerythrine (1 microM) but not sanguinarine caused moderate inhibition of AhR activation by 10 picomolar dioxin (exponential phase of receptor activation). In contrast, AhR activation by 2.5 nM dioxin (saturated receptor) was not affected by either alkaloid tested. In conclusion, the findings presented here favor rather for inactivity or modest inhibitory effect of QBAs on AhR signaling pathways in vitro than for the activation of the receptor. Regarding the concentrations of QBAs occurring in vivo, the use of products containing sanguinarine and/or chelerythrine has low toxicological potential in terms of the interactions with AhR signaling pathways.
Collapse
|
19
|
Sovadinová I, Bláha L, Janosek J, Hilscherová K, Giesy JP, Jones PD, Holoubek I. Cytotoxicity and aryl hydrocarbon receptor-mediated activity of n-heterocyclic polycyclic aromatic hydrocarbons: structure-activity relationships. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2006; 25:1291-7. [PMID: 16704060 DOI: 10.1897/05-388r.1] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Toxic effects of many persistent organic pollutants (e.g., polychlorinated biphenyls or polychlorinated dibenzo-p-dioxins and furans) are mediated via the aryl hydrocarbon receptor (AhR). Although polycyclic aromatic hydrocarbons (PAHs) and their derivatives also activate AhR, their toxic effects remain to be fully elucidated. In the present study, we used the in vitro H4IIE-luc transactivation cell assay to investigate cytotoxicity and potencies to activate AhR by 29 individual PAHs and their N-heterocyclic derivatives (aza-PAHs). The aza-PAHs were found to be significantly more cytotoxic and more potent inducers of AhR than their unsubstituted analogues. Several aza-PAHs, such as dibenz[a,h]acridine or dibenz[a,i]acridine, activated AhR within picomolar concentrations, comparable to the effects of reference 2,3,7,8-tetrachlorodibenzo-p-dioxin. Ellipsoidal volume, molar refractivity, and molecular size were the most important descriptors derived from the modeling of quantitative structure-activity relationships for potencies to activate AhR. Comparable relative toxic potencies (induction equivalency factors) for individual aza-PAHs are derived, and their use for evaluation of complex contaminated samples is discussed.
Collapse
|
20
|
Machala M, Bláha L, Lehmler HJ, Plísková M, Májková Z, Kapplová P, Sovadinová I, Vondrácek J, Malmberg T, Robertson LW. Toxicity of hydroxylated and quinoid PCB metabolites: inhibition of gap junctional intercellular communication and activation of aryl hydrocarbon and estrogen receptors in hepatic and mammary cells. Chem Res Toxicol 2004; 17:340-7. [PMID: 15025504 DOI: 10.1021/tx030034v] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In the present study, a series of 32 hydroxy- and dihydroxy-polychlorinated biphenyls (OH-PCBs) and PCB-derived quinones were prepared and evaluated for their in vitro potencies to downregulate gap junctional intercellular communication (GJIC) and to activate the aryl hydrocarbon receptor (AhR) and the estrogen receptor alpha (ER) in well-established liver and mammary cell models. The rat liver epithelial cell line WB-F344 was used for in vitro determination of GJIC inhibition; the AhR-inducing activity was determined in the rat hepatoma H4IIE.Luc cells stably transfected with a luciferase reporter gene; ER-mediated activity was measured in two breast carcinoma cell lines, MVLN and T47D.Luc, stably transfected with luciferase under the control of estrogen responsive element. Acute inhibition of GJIC, potentially associated with tumor promotion, was detected after treatment with all OH-PCBs under study, with the persistent OH-PCBs being the strongest ones. Several compounds were found to significantly induce the AhR-mediated activity, including 4'-OH-PCB 79, a metabolite of PCB 77, and 2-(4'-chloro)- and 2-(3',4'-dichloro)-1,4-benzoquinones and 1,4-hydroquinones. Low molecular weight OH-PCBs, such as 3'-hydroxy, 4'-, and 3',4'-dihydroxy-4-chlorobiphenyl, elicited significant estrogenic activity and potentiated effect of 17beta-estradiol. Antiestrogenic potencies, determined in the presence of 17beta-estradiol, were found for persistent 4-OH-PCB 187, 4-OH-PCB 146, and some low chlorinated PCB derivatives. However, no apparent association between induction of AhR activity and antiestrogenicity was observed. The majority of the OH-PCBs suppressed the 17beta-estradiol response only at cytotoxic concentrations. Spearman's rank correlations were calculated for these biological data and the physicochemical descriptors, hydrophobicity (log P), molar volume, pKa, log D, and dihedral angle. Significant correlations were found between potency to downregulate GJIC and log P and molar volume (R = -0.7, p < 0.0001). Antiestrogenic effects were also negatively correlated with hydrophobicity and molar volume. No significant correlations among other biological end points and the physicochemical descriptors were observed for the entire set of compounds. These results show that oxygenated PCB metabolites are capable of multiple adverse effects, including gap junction inhibition, AhR-mediated activity, and (anti)estrogenicity. The inhibition of GJIC by OH-PCBs represents a novel mode of action of both the lower chlorinated and the persisting high molecular weight OH-PCBs.
Collapse
|