Influence of perfluoroalkyl substances, with focus on perfluorobutanoic acid on the responding characteristics and molecular mechanisms of Thalassiosira pseudonana.

Perfluoroalkyl substances (PFAS) are widely dispersed persistent organic pollutants (POPs) throughout marine ecosystems. Due to ban of traditional long-chain PFAS, the emerging short-chain ones showed increased environmental detection as substitutes. As the foundation of aquatic food webs, microalgae play a pivotal role in the stability of marine environments. However, the toxicity of those short-chain PFAS was lack of investigation. Therefore, we chose 4C PFAS perfluorobutanoic acid (PFBA) and the marine model diatom Thalassiosira pseudonana as research targets, comprehensively studied the toxicity of PFBA to T. pseudonana in terms of the population growth, photosynthetic physiology and oxidative stress. Our results characterized the inhibited growth, inhibited photosynthetic parameters, increased reactive oxygen species (ROS) levels and activated antioxidant system under PFBA exposure. Further transcriptome analysis revealed the underlying molecular mechanisms: photosynthetic genes were slightly down-regulated and the expression of oxidative stress-related genes was enhanced; significant up-regulation of genes related to the DNA excision repair and replication-coupled DNA repair pathways; the expression of carbon metabolisms-related genes was increased, including the Calvin cycle, glycolysis, pentose phosphate pathway, tricarboxylic acid (TCA) cycle and fatty acid biosynthesis, that could provide sufficient energy for the recovery processes of microalgal cells. This study elucidated the underlying toxic mechanisms of PFBA on phytoplankton, and provided novel insights for assessing the environmental risks of PFAS.

Environmental Stability and Transmissibility of Enveloped Viruses at Varied Animate and Inanimate Interfaces.

Enveloped viruses have been the leading causative agents of viral epidemics in the past decade, including the ongoing coronavirus disease 2019 outbreak. In epidemics caused by enveloped viruses, direct contact is a common route of infection, while indirect transmissions through the environment also contribute to the spread of the disease, although their significance remains controversial. Bridging the knowledge gap regarding the influence of interfacial interactions on the persistence of enveloped viruses in the environment reveals the transmission mechanisms when the virus undergoes mutations and prevents excessive disinfection during viral epidemics. Herein, from the perspective of the driving force, partition efficiency, and viral survivability at interfaces, we summarize the viral and environmental characteristics that affect the environmental transmission of viruses. We expect to provide insights for virus detection, environmental surveillance, and disinfection to limit the spread of severe acute respiratory syndrome coronavirus 2.

Transcriptome reveals overview of Ca2+ dose-dependent metabolism disorders in zebrafish larvae after Cd2+ exposure.

Cadmium (Cd), a ubiquitous environmental hazardous heavy metal, poses a significant threat to the health of aquatic organisms, including teleosts. Although the toxic profile of Cd is well recognized, little is known regarding the overall view of toxic responses to varying aquatic environmental parameters (e.g., water hardness) at an individual level. Herein, differences in water hardness were partially mimicked by adjusting Ca2+ levels in E3 medium. As an in vivo model, zebrafish embryos were exposed to variable Ca2+ levels (NV, normal Ca2+; LV, low Ca2+; HV, high Ca2+) alone or combined with 30.7 µg/L Cd2+ (NC, LC, and HC, respectively) until 144 hr post-fertilization. The genome-wide transcriptome revealed differentially expressed genes between groups. Functional enrichment analysis found that biological processes related to metabolism, particularly lipid metabolism, were significantly disrupted in NC and LC treatments, while a remission was observed in the HC group. Biochemical assays confirmed that the decrease in Ca2+ enhanced synthesis, inhibited mobilization and increased the storage of lipids in Cd2+ treatments. This study suggests that the toxic effect of Cd on biological pathways will be influenced by Ca2+, which will improve the toxicological understanding and facilitate accurate assessment of Cd.

Disturbed Gut-Liver axis indicating oral exposure to polystyrene microplastic potentially increases the risk of insulin resistance.

Human uptake abundance of microplastics via various pathways, and they accumulate in human liver, kidney, gut and even placenta (especially with a diameter of 1 µm or less). Recent scientific studies have found that exposure to microplastics causes intestinal inflammation and liver metabolic disorder, but it remains largely unknown that whether the damage and inflammation may cause further development of severe diseases. In this study, we discovered one of such potential diseases that may be induced by the exposure to small-sized microplastics (with a diameter of 1 µm) performing a multi-organ and multi-omics study comprising metabolomics and microbiome approaches. Unlike other animal experiments, the dosing strategy was applied in mice according to the daily exposure of the highly exposed population, which was more environmentally relevant and reflective of real-world human exposure. Our studies on the gut-liver axis metabolism have shown that the crosstalk between the gut and liver ultimately leaded to insulin resistance and even diabetes. We proactively verified this hypothesis by measuring the levels of fasting blood glucose and fasting insulin, which were found significantly elevated in the mice with microplastics exposure. These results indicate the urgent need of large-scale cohort evaluation on epidemiology and prognosis of insulin resistance after microplastics exposure in future.

Inflammation and accompanied disrupted hematopoiesis in adult mouse induced by rare earth element nanoparticles.

Rare earth element nanoparticles (REE NPs) or agents have been used extensively in various fields. Human exposure to REE NPs is an increasing concern. To date, REE NP-mediated comprehensive immune responses after incorporation into the body remain unclear. In our study, using gadolinium oxide NPs (Gd2O3) as a typical REE NP, we systematically investigated immune responses in vivo. The liver and spleen were the main sites where Gd2O3 retained and accumulated, while Gd2O3 content per unit tissue mass in the spleen was 4.4 times higher than that in the liver. Gd2O3 increased the number of monocyte-derived macrophages and myeloid-derived dendritic cells (M-DCs) in the liver. In the spleen, Gd2O3 caused infiltration of neutrophils, M-DCs, and B cells. The accumulation of Gd2O3 in the liver or spleen also contributed to an increased concentration of cytokines in peripheral blood. In both the bone marrow and spleen, Gd2O3 led to increased populations of hematopoietic stem cells (HSCs), multipotent progenitors, and common lymphoid progenitors. Compared to the decreased monocytes in peripheral blood on day 2, a significant decrease of circulating lymphocytes on day 7 was still observed, suggesting the exposure duration led to variable effects. This might be explained by the sustained accumulation of Gd2O3 in the liver and spleen. Together, our study systemically depicted the alterations in mature immune alterations together with hematopoiesis in both myeloid and lymphoid lineages induced by Gd2O3 exposure. Our findings will facilitate a comprehensive understanding of the interactions of immune system with REE NPs in vivo.

Ammonium transporters cooperatively regulate rice crown root formation responding to ammonium nitrogen.

Crown roots (CRs) are major components of the rice root system. They form at the basal node of the shoot, and their development is greatly influenced by environmental factors. Ammonium nitrogen is known to impact plant root development through ammonium transporters (AMTs), but it remains unclear whether ammonium and AMTs play roles in rice CR formation. In this study, we revealed a significant role of ammonium, rather than nitrate, in regulating rice CR development. High ammonium supply increases CR formation but inhibits CR elongation. Genetic evidence showed that ammonium regulation of CR development relies on ammonium uptake mediated jointly by ammonium transporters OsAMT1;1, OsAMT1;2; OsAMT1;3, and OsAMT2;1, but not on root acidification which was the result of ammonium uptake. OsAMTs are also needed for glutamine-induced CR formation. Furthermore, we showed that polar auxin transport dependent on the PIN auxin efflux carriers acts downstream of ammonium uptake and assimilation to activate local auxin signaling at CR primordia, in turn promoting CR formation. Taken together, our results highlight a critical role for OsAMTs in cooperatively regulating CR formation through regulating auxin transport under nitrogen-rich conditions.

Expression of fatty acid-binding protein-4 in gastrointestinal stromal tumors and its significance for prognosis.

BACKGROUND: Fatty acid-binding proteins (FABPs) have been found to be involved in tumorigenesis and development. However, the role of FABP4, a member of the FABPs, in GISTs (Gastrointestinal stromal tumors) remains unclear. This study aimed to investigate the expression of FABP4 and its prognostic value in GISTs. METHODS: FABP4 expression in 125 patients with GISTs was evaluated by immunohistochemical analysis of tissue microarrays. The relationship between FABP4 expression and clinicopathological features and prognosis of GISTs was analyzed. RESULTS: Multiple logistic regression analysis showed that expression of FABP4 correlated with tumor size and mitotic index. Furthermore, FABP4 level, tumor size, mitotic index, and high AFIP-Miettinen risk were independent prognostic factors in GISTs. The Kaplan-Meier survival curve showed that the 5-year survival rate of patients with high-FABP4 expression GISTs was lower. CONCLUSIONS: These results suggested that high-FABP4 expression might be a marker of malignant phenotype of GISTs and poor prognosis.

Toxicity of Tetrabromobisphenol A and Its Derivative in the Mouse Liver Following Oral Exposure at Environmentally Relevant Levels.

As typical brominated flame retardants (BFRs), tetrabromobisphenol A (TBBPA) and its derivative TBBPA-bis(2,3-dibromopropyl ether) (TBBPA-BDBPE) are ubiquitous in various environmental compartments. However, the potential health risk posed by these compounds, especially at environmentally relevant levels, remains unclear. In this study, using adult male mice, we investigated the toxicity of orally administered TBBPA and TBBPA-BDBPE at an environmentally relevant dose (57 nmol/kg body weight). After a single exposure and daily exposure, we assessed lipid metabolism homeostasis, the transcriptome, and immune cell components in the liver. We found that the single exposure to TBBPA or TBBPA-BDBPE alone increased the number of hepatic macrophages, induced alterations in the levels of lipids, including triacylglycerol and free fatty acids, and caused transcriptome perturbation. The results from the daily administration groups showed that TBBPA and TBBPA-BDBPE both significantly increased the triacylglycerol content; however, the elevation of hepatic macrophages was observed only in the TBBPA-BDBPE treatment group. This study confirmed that environmentally relevant levels of TBBPA and TBBPA-BDBPE are toxic to the liver. Our findings revealed that dysfunction of the liver is a health concern, following exposure to BFRs, even at very low concentrations. The chronic effects induced by TBBPA and its derivatives should be further investigated.

Inherited and acquired corona of coronavirus in the host: Inspiration from the biomolecular corona of nanoparticles.

The family of coronavirus are named for their crown shape. Encoded by the genetic material inherited from the coronavirus itself, this intrinsic well-known "viral corona" is considered an "inherited corona". After contact with mucosa or the entrance into the host, bare coronaviruses can become covered by a group of dissolved biomolecules to form one or multiple layers of biomolecules. The layers acquired from the surrounding environment are named the "acquired corona". We highlight here the possible role of the acquired corona in the pathogenesis of coronaviruses, which will generate fresh insight into the nature of various coronavirus-host interactions.