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Environmental Monitoring and Assessment – Normal Response Models
Published in Song S. Qian, Mark R. DuFour, Ibrahim Alameddine, Bayesian Applications in Environmental and Ecological Studies with R and Stan, 2023
Song S. Qian, Mark R. DuFour, Ibrahim Alameddine
Microcystins are a class of over 50 toxins (congeners) produced by certain freshwater cyanobacteria (commonly known as blue-green algae). They can cause serious liver damage. A U.S. EPA report cites a study showing that 80 percent of samples in Canada and U.S. were positive for microcystins and 4.3 percent were above the World Health Organization (WHO) guideline of 1 μg/L [U.S. EPA, 2015].
Orders Norzivirales and Timlovirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
The MS2 VLP-based armored RNA standard was applied to measure microcystin synthetase E gene (mcyE) expression in toxic Microcystis sp., since microcystin was a secondary metabolic peptide toxin known to cause hepatotoxicosis and carcinogenicity in vertebrates (Rueckert and Cary 2009; Wood et al. 2011).
Non-Vaccine VLPs
Published in Paul Pumpens, Single-Stranded RNA Phages, 2020
Then, the MS2 VLP-based armored RNA standard was applied to measure microcystin synthetase E gene (mcyE) expression in toxic Microcystis sp. (Rueckert and Cary 2009). It was highly important, since microcystin was a secondary metabolic peptide toxin known to cause hepatotoxicosis and carcinogenicity in vertebrates. It was produced by various bloom-forming cyanobacterial species constituting a serious threat to the quality of freshwater reservoirs worldwide. This important study indicated a growth phase−dependent expression of the mcyE gene, with the maximal level of expression observed during mid-log growth. With progressing age of the cultures, the mcyE was gradually down-regulated, with expression levels having declined by more than three orders of magnitude during the stationary growth phase (Rueckert and Cary 2009; Wood et al. 2011).
High-throughput sequencing provides an insight into the hepatotoxicity mechanism of MC-LR in HepG2 cells
Published in Toxin Reviews, 2018
Microcystins exposure can cause many abnormal gene expression in animals in vivo and cells in vitro (Harke & Gobler, 2013; Zeller et al., 2012). In this study, there were hundreds or even thousands of DEGs detected in the MC-LR-treated HepG2 cells compared to the control cells through RPKM estimation by using RNA-Seq. To narrow the scope of target genes, 532 and 984 mRNAs were found to be significantly altered in 0.5 and 50 μM MC-LR treated cells compared to the control cells, respectively, by improving differentially expressed multiples, which suggested that highest concentration (50 μM) of MC-LR exposure could cause more gene expression changes. This result indicates that MC-LR-hepatotoxicity is concentration-dependent (Ma et al., 2016) and different concentrations of MC-LR probably activate different signaling pathways and lead to different outcomes or phenotypes. Moreover, the selected mRNAs (ATXN7, Caspase-9, c-fos, IL-1β, IL-8, NFKBIZ, VEGFA, CYP11A1, MMP-7 and PLA2G3) from DEGs examined by qRT-PCR were consistently up or downregulated in response to MC-LR-exposure, which confirmed the validity of high-throughput sequencing (Wang et al., 2009).
Milk thistle (Silybum Marianum) as an antidote or a protective agent against natural or chemical toxicities: a review
Published in Drug and Chemical Toxicology, 2020
Sahar Fanoudi, Mohaddeseh Sadat Alavi, Gholamreza Karimi, Hossein Hosseinzadeh
Microcystin-LR (MC-LR) is a potent cyclic peptide toxin produced by cyanobacteria (blue-green Microcystis aeruginosa) (de Figueiredo et al. 2004). This toxin has been known as a reason of even death and human hepatotoxicity (Xu et al. 2007).