Functional impairment triggered by altertoxin II (ATXII) in intestinal cells in vitro: cross-talk between cytotoxicity and mechanotransduction

Abstract

Intestinal cells are able to continuously integrate response to multiple stimuli/stressors; these include the concomitant activation of “chemically driven” pathways, of paramount importance in the response to toxicants, as well as physical stimulation derived from motility. Altertoxin II (ATXII, 0.1, 1 and 10 µM), a mycotoxin produced by the food contaminant fungus Alternaria alternata was studied in HT-29 intestinal adenocarcinoma cells and in non-transformed intestinal epithelial cells, HCEC. One-hour incubation with ATXII was sufficient to trigger irreversible cytotoxicity in both cell types, as well as to modify cellular responses to concomitant pro-oxidant challenge (H2O2, 100–500 µM, DCF-DA assay) suggesting that even relatively short-time exposure of the intestinal cells could be sufficient to alter their functionality. Combination of ATXII (1 µM) with physical stimulation typical of the intestinal compartment (shear stress) revealed differential response of tumor-derived epithelial cells HT-29 in comparison to HCEC, in particular in the localization of the transcription factor Nrf2 (NF-E2-related factor 2). Moreover, ATXII reduced the migratory potential of HCEC as well as their membrane fluidity, but had no respective impact on HT-29 cells. Taken together, ATXII appeared to alter predominantly membrane functionality in HCEC thus hampering crucial functions for cellular motility/turnover, as well as barrier function of healthy intestinal cells and had very limited activity on the tumor counterparts.

Exploring the dermotoxicity of the mycotoxin deoxynivalenol: combined morphologic and proteomic profiling of human epidermal cells reveals alteration of lipid biosynthesis machinery and membrane structural integrity relevant for skin barrier function

“…Membrane fluidity was measured adapting to the protocols from Zhang et al (2011) andDel Favero et al (2018b). Briefly, cells were either pre-incubated with the toxin (DON 24 h 0.1-10 μM) or challenged with the mycotoxin after the incubation with 1-pyrenedecanoic acid (PDA; Sigma Aldrich, 37 °C 1 h).…”

The Challenge of Classifying Metastatic Cell Properties by Molecular Profiling Exemplified with Cutaneous Melanoma Cells and Their Cerebral Metastasis from Patient Derived Mouse Xenografts

“…Immunolocalization Nrf2-For the localization of Nrf2, an immunofluorescence experiments were performed for all the melanoma variants as previously described (19,20). Briefly, cells were seeded on -Slides (35000 cells/well, Ibitreat coating, ibidi GmbH Martinsried, Germany), fixed with pre-warmed formaldehyde (FA, 3.7%, 15 min) and permeabilized with Triton X (0.2%, 10 min).…”

Alternaria alternata Toxins Synergistically Activate the Aryl Hydrocarbon Receptor Pathway In Vitro

“…Besides, AOH was reported to exhibit cytotoxic [ 8 ], clastogenic [ 19 ], and immunomodulatory properties [ 20 , 21 , 22 , 23 ] in vitro as well as fetotoxic [ 24 ] capacities in vivo and to possess estrogenic as well as other endocrine disruptive potentials [ 19 , 25 ]. The perylene quinone ATX-II was previously shown to exert genotoxic capacities [ 26 ], alter cell membrane biophysical properties of intestinal cancer cells [ 27 ], and inhibit the NF-κB pathway in THP-1 derived macrophages [ 28 ]. Both ATX-I and ATX-II were reported to possess mutagenic activity in S. typhimurium , with a substantially lower potency for ATX-I [ 5 ], while the nitrosylation of ATX-I in turn was found to increase mutagenicity against two strains of Salmonella [ 29 ].…”