Project description:BACKGROUND: Uranium (U) is a naturally occurring radionuclide that has been found in the aquatic environment due to anthropogenic activities. Exposure to U may pose risk to aquatic organisms due to its radiological and chemical toxicity. The present study aimed to characterize the chemical toxicity of U in Atlantic salmon (Salmo salar) using depleted uranium (DU) as a test model. The fish were exposed to three environmentally relevant concentrations of DU (0.25, 0.5 and 1.0 mg U/L) for 48 h. Hepatic transcriptional responses were studied using microarrays in combination with quantitative real-time reverse transcription polymerase chain reaction (qPCR). Plasma variables and chromosomal damages were also studied to link transcriptional responses to potential physiological changes at higher levels. RESULTS: The microarray gene expression analysis identified 847, 891 and 766 differentially expressed genes (DEGs) in the liver of salmon after 48 h exposure to 0.25, 0.5 and 1.0 mg/L DU, respectively. These DEGs were associated with known gene ontology functions such as generation of precursor metabolites and energy, carbohydrate metabolic process and cellular homeostasis. The salmon DEGs were then mapped to mammalian orthologs and subjected to protein-protein network and pathway analysis. The results showed that various toxicity pathways involved in mitochondrial functions, oxidative stress, nuclear receptor signaling, organ damage were commonly affected by all DU concentrations. Eight genes representative of several key pathways were further verified using qPCR No significant formation of micronuclei in the red blood cells or alterations of plasma stress variables were identified. CONCLUSION: The current study suggested that the mitochondrion may be a key target of U chemical toxicity in salmon. The induction of oxidative stress and uncoupling of oxidative phosphorylation may be two potential modes of action (MoA) of DU. These MoAs may subsequently lead to downstream events such as apoptosis, DNA repair, hypoxia signaling and immune response. The early toxicological mechanisms of U chemical toxicity in salmon has for the first time been systematically profiled. However, no other physiological changes were observed. Future efforts to link transcriptional responses to adverse effects have been outlined as important for understanding of potential risk to aquatic organisms.

Project description:In spite of many reports on the toxicity of silver nanoparticles (AgNPs), the mechanisms underlying the toxicity are far from clear. The present study conducted transcriptome and microRNAome sequencing for Euplotes vannus to understand the molecular mechanisms by which this protist copes with AgNPs exposure. By transcriptome profiling, 1884 and 5834 differentially expressed genes (DEGs) were identified after one hour and 12 hours exposure to 15 mg/L AgNPs, respectively. From microRNAsome profiling, totally 16 differentially expressed microRNAs were identified under AgNPs stress.In spite of many reports on the toxicity of silver nanoparticles (AgNPs), the mechanisms underlying the toxicity are far from clear. The present study conducted transcriptome and microRNAome sequencing for Euplotes vannus to understand the molecular mechanisms by which this protist copes with AgNPs exposure. By transcriptome profiling, 1884 and 5834 differentially expressed genes (DEGs) were identified after one hour and 12 hours exposure to 15 mg/L AgNPs, respectively. The DEGs were significantly enriched in macropinocytosis and phagocytic vesicles suggesting that the uptake of AgNPs may be mediated by endocytic pathways, while the differential expression of ABC transporters and copper-transporting ATPase implicates active efflux transport of Ag. Several DNA repair pathways were also significantly enriched with differentially expressed cell cycle control genes implying that exposure to AgNPs might have caused DNA damage and G2/M cell cycle arrest. The damage might have resulted from increased ROS production, as evidenced by elevated expression of several antioxidants genes to combat oxidative stress. From microRNAsome profiling, totally 16 differentially expressed microRNAs were identified under AgNPs stress. Integrated analysis of the microRNA and mRNA expression profiles found that the differentially expressed microRNAs target a series of genes involved in many important biological processes, suggesting that E. vannus exposure elicited a broad post-transcriptional regulatory mechanism through microRNAs–mRNAs–biological functions network to cope with the toxicity of AgNPs.

Project description:Atherosclerosis is a multifactorial disease that preferentially develops in specific regions in the arterial tree. This characteristic is mainly attributed to the unique pattern of hemodynamic shear stress in vivo. High laminar shear stress (LS) found in straight lumen exerts athero-protective effects. Low or oscillatory shear stress (OS) present in regions of lesser curvature and arterial bifurcations predisposes arterial intima to atherosclerosis. Shear stress-regulated endothelial function plays an important role in the process of atherosclerosis. Most in vitro research studies focusing on the molecular mechanisms of endothelial function are performed in endothelial cells (ECs) under cultured static (ST) condition. Some findings, however, are not recapitulated in subsequent translational studies, mostly likely due to the missing biomechanical milieu. Here, we profiled the whole transcriptome of primary human coronary arterial endothelial cells (HCAECs) under different shear stress conditions with RNA sequencing. Among 16,313 well-expressed genes, we detected 8,177 that were differentially expressed in OS vs. LS conditions and 9,369 in ST vs. LS conditions. Notably, only 1,618 were differentially expressed in OS vs. ST conditions. Hierarchical clustering of ECs demonstrated a strong similarity between ECs under OS and ST conditions at the transcriptome level. Subsequent pairwise heat mapping and principal component analysis gave further weight to the similarity. At the individual gene level, expressional analysis of representative well-known genes as well as novel genes showed a comparable amount at mRNA and protein levels in ECs under ST and OS conditions. In conclusion, the present work compared the whole transcriptome of HCAECs under different shear stress conditions at the transcriptome level as well as at the individual gene level. We found that cultured ECs are significantly different from those under LS conditions. Thus using cells under ST conditions is unlikely to elucidate endothelial physiology. Given the revealed high similarities of the endothelial transcriptome under OS and ST conditions, it may be helpful to understand the underlying mechanisms of OS-induced endothelial dysfunction from static cultured endothelial studies.

Project description:Background and aimsThe new coronavirus disease (COVID-19) is a systemic disease. Mounting evidence depict signs and symptoms involving multiple organs, most of which supported by pathological data. A plausible link to these manifestations is vascular and endothelial dysfunction/damage. However, much of the current knowledge relies on opinion and incipient evidence. We aim to objectively appraise current evidence on the association between COVID-19 and vascular disease, specifically endotheliitis and vasculitis.MethodsTwo researchers independently entered the search terms COVID-19 OR SARS-CoV-2 AND vasculitis, endotheliitis OR endothelium in the following online platforms: MedRxiv and LitCovid (PubMed). The search period was set from November 1, 2019 to August 28, 2020. Manuscripts with unavailable full texts, not in English, mainly on pre-clinical data, presenting only study designs or not directly related to the topics of this review were excluded. Retrospective and prospective studies, especially longitudinal ones, were given priority to the purpose of this review. Since there was paucity of prospective controlled evidence, case reports/series were also considered.ResultsA total of 318 manuscripts were initially found. Sixty-seven (21%) were excluded: 59 (18.5%) met exclusion criteria and 8 (2.5%) were duplicates. One hundred and forty-two manuscripts (44,6%) did not provide original data and were also excluded: 35 (11%) were comments, 108 (33.9%) reviews; 1 (0.3%) position paper. One hundred and seven (33.6%) studies were considered for the present scoping review: 81 (25,5%) case reports/series; 18 (5.7%) prospective; 8 (2.5%) retrospective. Viral inclusions in endothelial cells, mononuclear cell infiltrates in the intima of small vessels and markers of endothelial cell apoptosis were demonstrated. Specificities of COVID-19 may lead to diverse vascular manifestations in different levels of the vascular bed.ConclusionsEvidence indicates that COVID-19 targets vasculature and endothelium. However, high quality data is still lacking and studies with prospective designs and appropriately matched controls are needed.

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Transcriptomic and microRNAomic profiling reveals multi-faceted mechanisms to cope with phosphate stress in a dinoflagellate.

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Transcriptomic and microRNAomic profiling reveals multi-faceted mechanisms to cope with phosphate stress in a dinoflagellate.

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