Project description:Persistent and ubiquitous organic pollutants, such as the polycyclic aromatic hydrocarbon benzo[⍺]pyrene (BaP), represent a major threat to aquatic organisms and human health. Beside some well-documented adverse effects on the development and reproduction of aquatic organisms, BaP was recently shown to affect fish bone formation and skeletal development through mechanisms that remain poorly understood. In this work, several bone-related in vivo assays were used in zebrafish to evaluate the osteotoxic effects of BaP during bone development and regeneration. Exposure to BaP for 3 days induced a dose-dependent reduction of the size of the opercular bone in 6 days post-fertilization (dpf) larvae, and affected osteoblast maturation as observed by the expression of the mature marker, osteocalcin. Exposure to BaP for 27 days affected the development of the axial skeleton and increased the incidence and severity of skeletal deformities. During bone regeneration, BaP affected the mineralization of newly formed fin rays and scales, while it impaired fin ray patterning and scale shape, through mechanisms that may involve an imbalance of bone remodeling. Transcriptomic and gene expression analyses indicate that BaP induced the activation of xenobiotic and metabolic pathways, while negatively impacting extracellular matrix formation and organization. Interestingly, BaP exposure positively regulated inflammation markers in 6 dpf larvae and increased neutrophil recruitment. A direct interaction between neutrophils and bone extracellular matrix or bone forming cells was observed in vivo, suggesting a role for neutrophils in the mechanisms underlying BaP osteotoxicity. Our work provides novel data on the cellular and molecular players involved in BaP osteotoxicity and brings new insights into a possible role for neutrophils in inflammatory bone reduction.
Project description:In this research, we used MeDIP-sequencing technology to detect genome-wide methylation changes in benzo[a]pyrene(BaP)-exposed zebrafish larvae. We identified differentially methylated genes are associated with many diseases, including development of brain, and central nervous system.This high-throughput sequencing could help us to understand new mechanisms of BaP toxicity.
Project description:Soil dwelling Aspergillus fungi possess the versatile metabolic capability to utilize complex organic compounds which are toxic to humans, yet the mechanisms they employ remain largely unknown. Benzo(a)pyrene is a common carcinogenic contaminant, posing a significant concern for human health. Here, we report that Aspergillus fungi can degrade benzo(a)pyrene effectively. In Aspergillus nidulans, exposure to benzo(a)pyrene results in transcriptomic and metabolic changes associated with cellular growth and energy generation, implying that the fungus utilizes benzo(a)pyrene as a food. Importantly, we identify and characterize the conserved bapA gene encoding a cytochrome P450 monooxygenase that exerts the first step in the degradation of benzo(a)pyrene. We further demonstrate that the fungal NF-κB-type global regulators VeA and VelB are required for benzo(a)pyrene degradation in A. nidulans, which occurs through expression control of bapA in response to nutrient limitation. Our study illuminates fundamental knowledge of fungal benzo(a)pyrene metabolism and provides novel insights into enhancing bioremediation potential.
Project description:We performed microarray-based expression profiling on liver of male zebrafish exposed to 5, 50, and 500 µg/L of benzo-[A]-pyrene (BAP) for 24 and 96 hours, to identify global transcriptional programs and biological pathways involved in BAP-induced adaptive responses under in vivo environment.
Project description:We performed microarray-based expression profiling on liver of male zebrafish exposed to 5, 50, and 500 µg/L of benzo-[A]-pyrene (BAP) for 24 and 96 hours, to identify global transcriptional programs and biological pathways involved in BAP-induced adaptive responses under in vivo environment. We analyzed 34 arrays of BAP-treated adult male zebrafish liver and 15 arrays of control fish.
Project description:Benzo(a)pyrene is a well-established human carcinogen in humans and rodents. In the present study, we sought to determine the dose- and time-dependent changes in gene expression upon oral exposure to benzo(a)pyrene. Adult male B6C3F1 mice were exposed to four doses of benzo(a)pyrene or vehicle control for three days and sacrificed 4 or 24 hours after the final exposure.
Project description:Benzo[a]pyrene is a Group 1 carcinogen. It undergoes metabolism in the liver through CYP1A1 and CYP1B1 enzymes. This study was conducted to investigate the response to benzo[a]pyrene in the liver when these enzymes are knocked down.
Project description:Benzo(a)pyrene is a well-established human carcinogen in humans and rodents. In the present study, we sought to determine the dose- and time-dependent changes in gene expression upon oral exposure to benzo(a)pyrene. Adult male MutaTMMouse were exposed to three doses of benzo(a)pyrene or vehicle control (olive oil) for 28 days and sacrificed three days after the final exposure.
Project description:Twenty-eight days after the initial seeding, the terminally differentiated HepaRG cells were treated with 2 µM benzo[a]pyrene (B[a]P) and benzo[e]pyrene (B[e]P) for 72 hours. Following the treatment, the cells were harvested by mild trypsinization, washed in phosphate-buffered saline, and immediately frozen at −80°C for subsequent analyses. Gene expression profiles in the HepaRG cells treated with B[a]P and B[e]P were investigated using Agilent whole genome 8x60K human microarrays according to the manufacturer’s instructions.