Biology subjects

Del Favero, G.

Publications and source records attributed to Del Favero, G..

5 recordsLinked to original sources

bioRxiv2026

Mechanistic characterization of tenuazonic acid-induced cellular stress responses in human esophageal KYSE-510 cells

Tenuazonic acid (TeA) is an emerging Alternaria mycotoxin frequently detected in food and feed commodities, raising concerns about its toxicological relevance. Chronic oral exposure to TeA has been reported to induce dysplastic alterations in the esophageal mucosa of mice, while human biomonitoring data indicate an association between TeA exposure and esophageal cancer, although a causal relationship has not yet been established. At a mechanistic level, the effects of TeA in esophageal cells remain poorly characterized. Therefore, this study investigated the impact of TeA on cytotoxicity, oxidative stress, DNA damage, mitochondrial homeostasis, cell-cycle distribution and transcriptomic stress responses in human esophageal KYSE-510 cells. TeA induced a concentration-dependent reduction in metabolic activity and total protein content after 24 h exposure to 0.1-100 {micro}M. Significant cytotoxicity was measured starting from 20 {micro}M. At sub-cytotoxic concentrations, TeA triggered rapid ROS formation within 5-30 min exposure and induced formamidopyrimidine-DNA glycosylase (FPG) sensitive DNA damage after 1 h exposure (5-7.5 {micro}M), indicating oxidative DNA lesions. In addition, TeA altered mitochondrial morphology after 4 h exposure at 7.5 {micro}M, manifested by shrinkage of the mitochondrial network area and perinuclear redistribution, while mitochondrial respiration showed only a non-significant tendency towards reduced respiratory capacity. RNA sequencing after 6 h exposure to 10 {micro}M TeA revealed oxidative stress-associated transcriptional changes, impaired antioxidant and stress-adaptive responses, and p53-associated stress signaling. Furthermore, TeA induced significant G2/M phase accumulation after 24 h exposure to 1-10 {micro}M. HighlightsO_LITeA triggers rapid oxidative stress in human esophageal KYSE-510 cells C_LIO_LISub-cytotoxic TeA induces FPG-sensitive oxidative DNA lesions C_LIO_LITeA disrupts mitochondrial morphology before overt cytotoxicity occurs C_LIO_LIRNA-seq reveals impaired antioxidant defense and p53-linked stress signaling C_LIO_LITeA promotes G2/M phase accumulation and concentration-dependent cytotoxicity C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=88 SRC="FIGDIR/small/736731v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@a496faorg.highwire.dtl.DTLVardef@1b42072org.highwire.dtl.DTLVardef@be5088org.highwire.dtl.DTLVardef@991b5b_HPS_FORMAT_FIGEXP M_FIG C_FIG

pharmacology and toxicology↗

bioRxiv2026

Modulation of NF-κB signaling by Alternaria mycotoxins: in vitro and in silico insights into molecular mechanisms of immunosuppression in THP-1 monocytes

Alternaria fungi produce various structurally diverse mycotoxins, several of which exhibit immunomodulatory properties. Among these, alternariol monomethyl ether (AME), alternariol (AOH), alterperylenol (ALTP), altertoxin I (ATX-I), and altersetin (AST) have been reported to suppress lipopolysaccharide (LPS)-induced inflammatory responses. However, the precise molecular mechanisms underlying these effects remain unclear. The present study aimed to elucidate how these selected Alternaria mycotoxins (0.1-50 {micro}M) target the NF-{kappa}B signaling pathway in THP-1 monocytes. Key components of the NF-{kappa}B cascade were analyzed by immunofluorescence microscopy, Western blotting and qRT-PCR. Nuclear translocation of NF-{kappa}B p65 and its phosphorylated form (p- NF-{kappa}B p65) was assessed by Western blot, while cytokine responses were determined at transcript (qRT-PCR) and protein (ELISA) levels. Moreover, in silico docking analyses were performed to investigate potential interactions of the toxins with IKK{beta}, and receptor-mediated crosstalk was studied using the glucocorticoid receptor (GR) antagonist RU486. Co-treatment with RU486 attenuated the immunosuppressive effects of 1 and 5 {micro}M AOH, indicating partial involvement of GR-dependent mechanisms. AME, AOH, ALTP, ATX-I, and AST increased total I{kappa}B levels while reducing its phosphorylated form. Additionally, AST and ALTP decreased the protein levels of Toll-like receptor 4 (TLR4), the I{kappa}B kinase (IKK) complex, NF-{kappa}B p65, and p- NF-{kappa}B p65. While AOH (5 {micro}M) and AST (25 {micro}M) reduced nuclear translocation of p65 and p-p65, ALTP (2 {micro}M) enhanced nuclear localization despite decreasing cytokine expression Together, these findings suggest toxin-specific interference at multiple regulatory levels of NF-{kappa}B signaling and provide novel mechanistic insight into the immunomodulatory effects of Alternaria mycotoxins.

pharmacology and toxicology↗

bioRxiv2025

Aetokthonotoxin, the causative agent of vacuolar myelinopathy, uncouples oxidative phosphorylation due to protonophore activity

Aetokthonotoxin (AETX) is an emerging environmental toxin produced by the freshwater cyanobacterium Aetokthonos hydrillicola. Accumulating in the food chain, it causes vacuolar myelinopathy, a neurological disease affecting a wide range of wildlife characterized by the development of large intra-myelinic vacuoles in the white matter of the brain. So far, the mode of action of AETX is unknown. After discovering that AETX is cytostatic and arrests cancer cell lines in G1-phase, metabolomic profiling of AETX-treated cells as well as an assessment of the physico-chemical properties of the compound suggested that AETX is a weakly acidic uncoupler of mitochondrial respiration. We confirmed this hypothesis by in vitro assays on mammalian cells, finding that AETX has the expected effects on the mitochondrial network morphology, mitochondrial membrane potential, and oxygen consumption rates, resulting in affected ATP generation. We confirmed that AETX is capable of transporting protons across lipid bilayers. In summary, we demonstrate that AETX is a protonophore that uncouples oxidative phosphorylation in mitochondria, the primary event of AETX intoxication. Significance statementAetokthonotoxin (AETX) is an emerging cyanotoxin. Produced by the cyanobacterium Aetokthonos hydrillicola, it is transferred through the food chain, affects the nervous system, and eventually causes mortality in animals of various taxa. Our finding that AETX is an unspecific uncoupler of mitochondrial respiration implies that it might also be harmful for human health upon ingestion and trophic accumulation. First steps towards a full risk assessment are needed. An important aspect in this regard is the elucidation of the toxins mode of action. We anticipate our findings to be a starting point for the development of an adverse outcome pathway addressing the formation of vacuolar myelinopathy, expanding the significance of our results to the future risk assessment of other environmental neurotoxins.

pharmacology and toxicology↗

bioRxiv2020

Eicosanoid content in fetal calf serum accounts for reproducibility challenges in cell culture

Reproducibility issues regarding in vitro cell culture experiments are related to genetic fluctuations and batch-wise variations of biological materials such as fetal calf serum (FCS). Genome sequencing may control the former, while the latter may remain unrecognized. Using a U937 macrophage model for cell differentiation and inflammation, we investigated whether the formation of effector molecules was dependent on the FCS batch used for cultivation. High resolution mass spectrometry was used to identify FCS constituents and to explore their effects on cultured cells evaluating secreted cytokines, eicosanoids and other inflammatory mediators. Remarkably, the FCS eicosanoid composition showed more batch-dependent variations than the protein composition. Efficient uptake of fatty acids from medium by U937 macrophages and inflammation-induced release thereof was evidenced using C13-labelled arachidonic acid, highlighting rapid lipid metabolism. For functional testing, FCS batch-dependent nanomolar concentration differences of two selected eicosanoids, 5-HETE and 15-HETE, were balanced out by spiking in. Culturing U937 cells at these defined conditions indeed resulted in significant proteome alterations indicating HETE-induced PPAR{gamma} activation, independently corroborated by HETE-induced formation of peroxisomes observed by high-resolution microscopy. In conclusion, the present data demonstrate that FCS-contained eicosanoids, subject to substantial batch-wise variation, may modulate cellular effector functions in cell culture experiments.

cell biology↗

bioRxiv2019

Neutrophil extracellular trap formation correlates with improved overall survival in ovarian cancer

It is still a question of debate whether neutrophils, often found in the tumor microenvironment, mediate tumor-promoting or rather tumor-inhibiting activities. The present study focusses on the involvement of neutrophils in high grade serous ovarian cancer (HGSOC). Multi-omics data comprising proteomics, eicosadomics, metabolomics, Luminex-based cytokinomics, and FACS data were generated from ascites samples. Integrated data analysis demonstrates a significant increase of neutrophil extracellular trap-(NET) associated molecules in non-miliary ascites samples. A co-association network analysis performed with the ascites data further revealed a striking co-correlation between NETosis-associated metabolites with several eicosanoids. Investigating primary neutrophils from healthy domors, NET formation was induced using ionomycin or phorbol ester. Data congruence with ascites analyses indicated the predominance of NOX-independent NETosis. NETosis is associated with S100A8/A9 release. An increase of the S100A8/CRP abundance ratio was found to correlate with improved survival of HGSOC patients. The analysis of additional five independent proteome studies with regard to S100A8/CRP ratios confirmed this observation. In conclusion, here we present evidence that increased NET formation relates to improved outcomes in cancer patients. Graphical abstractNETs releasing neutrophils through detaching of small tumor nods dictate the building of bigger in size and fewer in number of tumors in the non-miliary spreading tumor. Increased angiogenesis associated with increased blood circulation may contribute to less suppressive effects on NETs formation in the non-miliary tumor type. Tumor origin, i.e. fallopian tube for the miliary or ovary for the non-miliary tumors, may influence the angiogenesis and therewith - through facilitating of neutrophils activation - (co)determine the type of tumor spread. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=109 SRC="FIGDIR/small/862292v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@895250org.highwire.dtl.DTLVardef@17b2a78org.highwire.dtl.DTLVardef@1213959org.highwire.dtl.DTLVardef@3c35ed_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗