Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1211694 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Microcystins (MCs) are cyclic hepatotoxins produced worldwide by various species of cyanobacteria. Their structure includes two variable amino acids (AAs) and most of the studies focused on the most toxic variant: the microcystin LR (MC-LR). However, more than 80 MC variants have been described to date. Despite ingestion being the major pathway of human exposure, few in vivo studies have demonstrated macroscopic effects on the gastro-intestinal tract, but no data are available on the affected pathways by several variants on intestinal cells. Here, using a non-selective method, we investigated for the first time the effect of MC-RR and MC-LR on the human intestinal cell line Caco-2 and compared their response at the pangenomic scale. The cells were incubated for 4 hrs or 24 hrs with the same range of sub-lethal concentrations of MC-RR or MC-LR. Low effects were observed for both variants after a short-term exposure. On the contrary, dose-dependent modulations of the genes transcription levels were noticed with MC-RR and MC-LR after 24 hrs. Furthermore, the genomic profiles induced by both variants were similar suggesting a common toxicity mechanism but with higher modulation following MC-LR than MC-RR exposure. However, the functional annotation revealed major differences between the variants effects. Indeed, the well-known MC-LR affected mainly two pathways, the oxidative stress response and the cell cycle regulation, which did not elicit significant alteration following MC-RR exposure. This work is the first comparative description of the MC-LR and MC-RR effects on a human intestinal cell model. It allowed us to suggest differences in the mechanism of toxicity for MC-RR and MC-LR. These results illustrate that the toxicity of MC variants remains a key point for risk assessment. Differentiated Caco-2 cells were exposed to microcystins in free FCS culture medium for either 4 or 24 hours. Sub-lethal concentrations of 10, 50 and 100 M-BM-5M of MC-LR or MC-RR were chosen for 4 hours, while 1, 5 and 10 M-BM-5M were selected for 24 hours. For each condition (including the controls), the solvent concentration was fixed to 2% EtOH for MC-LR and 1.5% of 80% MeOH for MC-RR. Four to five culture replicates per condition were done.
2012-12-31 | E-GEOD-29861 | biostudies-arrayexpress
Project description:Microcystins (MCs) are cyclic hepatotoxins produced worldwide by various species of cyanobacteria. Their structure includes two variable amino acids (AAs) and most of the studies focused on the most toxic variant: the microcystin LR (MC-LR). However, more than 80 MC variants have been described to date. Despite ingestion being the major pathway of human exposure, few in vivo studies have demonstrated macroscopic effects on the gastro-intestinal tract, but no data are available on the affected pathways by several variants on intestinal cells. Here, using a non-selective method, we investigated for the first time the effect of MC-RR and MC-LR on the human intestinal cell line Caco-2 and compared their response at the pangenomic scale. The cells were incubated for 4 hrs or 24 hrs with the same range of sub-lethal concentrations of MC-RR or MC-LR. Low effects were observed for both variants after a short-term exposure. On the contrary, dose-dependent modulations of the genes transcription levels were noticed with MC-RR and MC-LR after 24 hrs. Furthermore, the genomic profiles induced by both variants were similar suggesting a common toxicity mechanism but with higher modulation following MC-LR than MC-RR exposure. However, the functional annotation revealed major differences between the variants effects. Indeed, the well-known MC-LR affected mainly two pathways, the oxidative stress response and the cell cycle regulation, which did not elicit significant alteration following MC-RR exposure. This work is the first comparative description of the MC-LR and MC-RR effects on a human intestinal cell model. It allowed us to suggest differences in the mechanism of toxicity for MC-RR and MC-LR. These results illustrate that the toxicity of MC variants remains a key point for risk assessment.
2012-12-31 | GSE29861 | GEO
Project description:Microcystins (MC) are toxins found in harmful algal blooms. The canonical MC mode of action (MOA) is the inhibition of protein phosphatases, but complete characterization of its toxicity pathway has yet to be identified. The existence of 100s of MC structural congeners further complicates risk estimates. This work employed RNA-seq to provide an unbiased and comprehensive characterization of cellular targets and impacted cellular processes of hepatocytes exposed to either MC-LR or MC-RR congeners. The human hepatocyte cell line, HepaRG, was treated with three concentrations of MC-LR or RR (1000, 100, 10 g/L) for two hours. Significant reduction in cell survival was observed in the LR1000 and LR100 treatments. RNA-seq was performed on the control groups and all concentrations of MC-LR and -RR and differentially expressed genes (DEGs) were identified. Genes and pathways associated with oxidative and endoplasmic reticulum stress, and the unfolded protein response (UPR) were highly enriched by both congeners. Enrichment of inflammatory pathways was also evident. In the cytotoxic LR1000 treatment, apoptotic pathways and related genes were identified, suggesting cells pursue both inflammation and apoptosis simultaneously and that cellular fate may be determined by the activation kinetics of jun N-terminal kinase (JNK). We present a model of MC toxicity where MCs cause the production of ROS and oxidative stress leading to ER stress and activation of the UPR. Under non-cytotoxic conditions this leads to an inflammatory and pro-survival cellular response mediated through up-regulation and activation of NF- and its inhibition of JNK. With acute MC exposure, increased ER stress results in the cellular program switching to favor apoptosis by inhibiting NF- resulting in sustained JNK activation and through the activation of C/EBP homologous protein (CHOP) via the protein kinase RNA-like endoplasmic reticulum kinase (PERK) arm of the UPR
2021-03-09 | GSE147999 | GEO
Project description:The expressions of piRNA in mouse sperm were altered by MC-LR-exposure or Hsp90aa1 shRNA. MC-LR could induce intergenerational toxicity.
2020-12-31 | GSE129849 | GEO
Project description:Elevated levels of adsorbable organic bromine compounds (AOBr) have been detected in German lakes, and cyanobacteria like Microcystis, which are known for the synthesis of microcystins, are one of the main producers of natural organobromines. However, very little is known about how environmental realistic concentrations of organobromines impact invertebrates. Here, the nematode C. elegans was exposed to AOBr-containing surface water samples and to a Microcystis aeruginosa enriched batch culture (MC-BA) and compared to single organobromines and microcystin-LR exposures. Stimulatory effects were observed in certain life trait variables, which were particularly pronounced in nematodes exposed to MC-BA. A whole genome DNA-microarray revealed that MC-BA led to the differential expression of more than 2000 genes, many of which are known to be involved in metabolic, neurologic, and morphologic processes. Moreover, the up-regulation of cyp- and the down-regulation of abu-genes suggested the presence of chronic stress. However, the nematodes were not marked by negative phenotypic responses. The observed difference in MC-BA and microcystin-LR (which impacted lifespan, growth and reproduction) exposed nematodes was hypothesized to be likely due to other compounds within the batch culture. Most likely the exposure to low concentrations of organobromines appears to buffer the effects of toxic substances, like microcystin-LR.
2015-05-12 | GSE68709 | GEO
Project description:We have builded a network including mRNA, miRNA, piRNA, lncRNA and circRNA after exposure to MC-LR for 6 months in testicular tissue. And we find MC-LR could induce testicular toxicity and apoptosis by disturbing the netwok.
2020-08-31 | GSE119044 | GEO
Project description:Elevated levels of adsorbable organic bromine compounds (AOBr) have been detected in German lakes, and cyanobacteria like Microcystis, which are known for the synthesis of microcystins, are one of the main producers of natural organobromines. However, very little is known about how environmental realistic concentrations of organobromines impact invertebrates. Here, the nematode C. elegans was exposed to AOBr-containing surface water samples and to a Microcystis aeruginosa enriched batch culture (MC-BA) and compared to single organobromines and microcystin-LR exposures. Stimulatory effects were observed in certain life trait variables, which were particularly pronounced in nematodes exposed to MC-BA. A whole genome DNA-microarray revealed that MC-BA led to the differential expression of more than 2000 genes, many of which are known to be involved in metabolic, neurologic, and morphologic processes. Moreover, the up-regulation of cyp- and the down-regulation of abu-genes suggested the presence of chronic stress. However, the nematodes were not marked by negative phenotypic responses. The observed difference in MC-BA and microcystin-LR (which impacted lifespan, growth and reproduction) exposed nematodes was hypothesized to be likely due to other compounds within the batch culture. Most likely the exposure to low concentrations of organobromines appears to buffer the effects of toxic substances, like microcystin-LR. Nematodes were exposed to filtrated samples of Lake Stößensee Berlin (August and October) and compared to the control-group (exposure to water). Furthermore, nematodes were exposed to filtrated M. aeruinosa batch culture samples and compared to another control-group (exposure to Z-Medium). Three samples (biological replicates) were prepared for each group.
2015-05-12 | E-GEOD-68709 | biostudies-arrayexpress
Project description:Harmful algal blooms (HABs) arise from the rapid growth of algae in both marine and freshwater ecosystems due to the continuous global temperature rise and anthropogenic eutrophication. Humans are at a great risk of exposure to toxins released from HABs through drinking water, food, and recreational activities, making HAB toxins contaminants of emerging concern (CECs). The impact of HAB toxins on women’s reproductive health, however, remains poorly understood. Here, we investigated the effects of microcystin-LR (MC-LR), the most common HAB toxin, on the ovary, the female gonad, and associated ovarian functions. The results of a chronic daily oral mouse exposure model and an acute exposure using the mouse superovulation model revealed that MC-LR accumulated in the ovary and environmentally-relevant exposure to MC-LR perturbed follicle-stimulating hormone (FSH)-dependent follicle maturation to disrupt ovulation and luteinization. Using an ex vivo mouse follicle maturation and ovulation assay and in vitro culture of human primary granulosa cells, mechanistic studies such as the single-follicle RNA sequencing analysis and others elucidated that MC-LR inhibited protein phosphatase 1 (PP1) and interfered with PP1-mediated PI3K/AKT/FOXO1 signaling in granulosa cells, which suppressed follicle maturation, ovulation, luteinization, and progesterone secretion. Together, our study demonstrates that environmentally-relevant exposure to MC-LR acts a PP1 inhibitor to interfere with the PI3K/AKT/FOXO1 signaling in granulosa cells, which disrupts follicle maturation and results in adverse female reproductive outcomes. As a newly identified ovarian endocrine disrupting chemical (EDC), exposure to MC-LR poses a serious threat to women’s reproductive health and fertility.
2024-06-15 | GSE201806 | GEO
Project description:Comparison of the MC-LR and MC-RR effects on Caco-2 cells
| PRJNA140949 | ENA