Project description:We treated GC-1 cells with 500 nM or 0 nM of MC-LR for 24 h.Next, total RNA from GC-1 cells of these two groups were extracted using TRIzol Reagent. The two small RNA libraries were prepared using the Illumina small RNA preparation kit and were deep-sequenced. After adapter sequences were trimmed, 10,824,057, and 11,566,902 small RNA reads that were smaller than 45 nucleotides were obtained from control group and MC-LR group, respectively. The sequences that correspond to known piRNAs were determined by perfect sequence matching to the NCBI database (http://www.ncbi.nlm.nih.gov). We identified 244066 reads of piRNAs and 220 unique piRNA sequences in control group and 359871 reads of piRNAs and 230 unique piRNA sequences in MC-LR group
Project description:The expressions of piRNA in mouse sperm were altered by MC-LR-exposure or Hsp90aa1 shRNA. MC-LR could induce intergenerational toxicity.
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.
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.
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.
Project description:Pregnant females were distributed into two experimental groups: control group and MC-LR group which were exposed to 0 and 10 μg/L of MC-LR through drinking water separately during fetal and lactational periods. In 30 days old, the animals were euthanized. Testes were determined to investigate the different expressions of piRNAs using a piRNA microarray.
Project description:Pregnant females were distributed into two experimental groups: control group and MC-LR group which were exposed to 0 and 10 μg/L of MC-LR through drinking water separately during fetal and lactational periods. In 30 days old, the animals were euthanized. Testes were determined to investigate the different expressions of piRNAs using a piRNA microarray.
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.
Project description:Microcystin-LR (MC-LR), the most toxic member of microcystin family, inhibits protein phosphatase PP2A, triggers oxidative stress and induces hepatotoxicity. Gene expression profiling of MC-LR treated larvae using DNA microarray analysis revealed effects in the retinal visual cycle and pigmentation synthesis pathways that have not been previously associated with MC-LR. Liver-related genes were also differentially expressed. The microarray data were confirmed by quantitative real-time PCR. Our findings provide new evidence that microcystin-LR exposure of zebrafish larvae modulates the retinal visual cycle and pigmentation synthesis pathways and ultimately alter larval zebrafish behavior