[Exposure characteristics and health risk assessment of 97 typical chemical pollutants in human serum].

Rapid industrial and agricultural developments in China have led to the wide use and discharge of chemical products and pesticides, resulting in extensive residues in environmental media. These residues can enter the human body through various pathways, leading to high exposure risks and health hazards. Because the human body is exposed to a variety of chemical pollutants, accurately quantifying the exposure levels of these pollutants in the human body and evaluating their health risks are of great importance. In this study, the serum concentrations of 97 typical chemical pollutants of 60 adults in central China were simultaneously determined using solid-phase extraction coupled with gas chromatography-tandem mass spectrometry (SPE-GC-MS/MS). In this method, 200 µL of a serum sample was mixed with 10 µL of an isotope-labeled internal standard solution. The sample was vortexed and refrigerated overnight at 4 ℃. Each sample was then deproteinized by the addition of 200 µL of 15% formic acid aqueous solution and vortexed. The serum sample was loaded into a preconditioned Oasis® PRiME HLB SPE cartridge and rinsed with 3 mL of methanol-water (6∶1, v/v). The SPE cartridge was subsequently vacuumed. The analytes were eluted with 3 mL of dichloromethane followed by 3 mL of n-hexane. The eluent was concentrated to near dryness under a gentle nitrogen stream and reconstituted with 100 µL of acetone. The samples were determined by GC-MS/MS and separated on a DB-5MS capillary column (30 m×0.25 mm×0.25 µm) with temperature programming. The column temperature was maintained at 70 ℃ for 2 min, increased at a rate of 25 ℃/min to 150 ℃, increased at a rate of 3 ℃/min to 200 ℃, and then held for 2 min. Finally, the column temperature was increased at a rate of 8 ℃/min to 300 ℃ and maintained at this temperature for 8 min. The samples were detected in multiple-reaction monitoring (MRM) mode and quantitatively analyzed using the internal standard method. Multiple linear regression models were used to analyze the effects of demographic characteristics, lifestyle habits, and diet on the concentrations of the chemical pollutants in the serum samples, and known biomonitoring equivalents (BEs) and human biomonitoring (HBM) values were combined to compute hazard quotients (HQs) and hazard indices (HIs) and evaluate the health risks of single and cumulative exposures to the chemical pollutants. The results showed that the main pollutants detected in human serum were organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). The detection rates of eight pollutants, including hexachlorobenzene (HCB) (100%), pentachlorophenol (PCP) (100%), p,p'-dichlorodiphenylene (p,p'-DDE) (100%), PCB-138 (100%), PCB-153 (98.3%), ß-hexachlorocyclohexane (ß-HCH) (91.7%), fluorene (Flu) (85.0%), and anthracene (Ant) (75.0%), were greater than 70%. The serum levels of ß-HCH were higher in females than in males, and age was positively correlated with exposure to p,p'-DDE, PCB-138, PCB-153, and ß-HCH. Increased exposure levels to p,p'-DDE and ß-HCH may be associated with a high frequency of meat intake, whereas increased exposure level to PCP may be associated with a high frequency of vegetable intake. The serum HQ of PCP was greater than 1 in 6.7% of the samples, and no risk was observed for HCB and p,p'-DDE exposure in the study population. Approximately 28.3% of the study subjects had HI values greater than 1. Overall, the general adult population in this region is widely exposed to a wide range of chemical pollutants, and gender, age, and diet are likely to be the main factors influencing the concentration of chemical pollutants. The health risk of single and compound exposures to chemical pollutants should not be ignored.

[Comparison of ecological characteristics of Carex tussock under natural and artificial reco-very.] / 人工恢复与自然恢复模式下苔草草丘生态特征比较.

We compared the ecological characteristics of tussock individuals and populations undergoing natural and artificial restoration in Carex tussock wetlands in the Sun Island in Harbin and identified the relationships between the growth of Carex tussock and environmental factors. Results showed that there were obvious seasonal dynamics in morphological characteristics of C. appendiculata. Tussocks grew rapidly from May to June, peaked in June, and then decreased steadily from July to August. There were significant differences in ecological characteristics of Carex tussocks between natural and artificial restorations. The morphological characteristics of individual tussock, including leaf area, leaf width, fresh weight per ramet, dry weight per ramet, and the hummock shape indicators (hummock height, diameter, volume and surface area) in natural restored area were significantly higher than those in artificial transplanting area. For the Carex tussock community, tussock density, coverage and biomass in natural restoration area were significantly lower than those in artificial transplanting area. Soil water content, water depth and hummock spacing in natural restoration area were significantly higher than those in artificial restoration area, which facilitated the formation and development of individual tussock. Higher transplanting density was the main factor leading to higher density, coverage, and biomass in artificial restoration area. Our results suggested that the distribution characteristics of tussocks in natural restoration area should be taken into account in future restoration and protection works. Appropriate adjustment of the distance between hummock (54.22-117.89 cm) and population density (1.9-3.1 ind·m-2), as well as proper water recharge measures in spring in arid areas to regulate soil water content and water depth, would be conducive to promoting the growth and rapid recovery of Carex tussock, which would maintain the long-term health and stability of tussock wetland.

Transcriptomic responses involved in enhanced production of hypocrellin A by addition of Triton X-100 in submerged cultures of Shiraia bambusicola.

The addition of surfactant is a useful strategy to enhance the product yield in submerged fermentation process. In this study, we sought to explore the mechanism for the elicitation of Triton X-100 on production of hypocrellin A (HA) in cultures of Shiraia bambusicola through transcriptomic analysis. Triton X-100 at 2.5% (w/v) not only induced HA biosynthesis in mycelia, but also stimulated the release of HA into the medium. We found 23 of 2463 transcripts, possible candidate genes for HA biosynthesis under Triton X-100 induction. Gene ontology (GO) analysis showed Triton X-100 treatment changed expression of genes involved in transmembrane transport and oxidation-reduction process, indicating that enhanced HA production was mainly due to both elicited biosynthesis in mycelium and the increased membrane permeability for HA release. These data provided new insights into elicitation of surfactants in submerged cultures of fungi.

CPUY201112, a novel synthetic small-molecule compound and inhibitor of heat shock protein Hsp90, induces p53-mediated apoptosis in MCF-7 cells.

Heat-shock protein 90 (Hsp90) is highly expressed in many tumor cells and is associated with the maintenance of malignant phenotypes. Targeting Hsp90 has had therapeutic success in both solid and hematological malignancies, which has inspired more studies to identify new Hsp90 inhibitors with improved clinical efficacy. Using a fragment-based approach and subsequent structural optimization guided by medicinal chemistry principles, we identified the novel compound CPUY201112 as a potent Hsp90 inhibitor. It binds to the ATP-binding pocket of Hsp90 with a kinetic dissociation (Kd) constant of 27 ± 2.3 nM. It also exhibits potent in vitro antiproliferative effects in a range of solid tumor cells. In MCF-7 cells with high Hsp90 expression, CPUY201112 induces the degradation of Hsp90 client proteins including HER-2, Akt, and c-RAF. We prove that treating MCF-7 cells with CPUY201112 results in cell cycle arrest and apoptosis through the wild-type (wt) p53 pathway. CPUY201112 also synergizes with Nutlin-3a to induce cancer cell apoptosis. CPUY201112 significantly inhibited the growth of MCF-7 xenografts in nude mice without apparent body weight loss. These results demonstrate that CPUY201112 is a novel Hsp90 inhibitor with potential use in treating wild-type p53 related cancers.

Discovery and Modification of in Vivo Active Nrf2 Activators with 1,2,4-Oxadiazole Core: Hits Identification and Structure-Activity Relationship Study.

Induction of phase II antioxidant enzymes by activation of Nrf2/ARE pathway has been recognized as a promising strategy for the regulation of oxidative stress-related diseases. Herein we report our effort on the discovery and optimization of Nrf2 activators with 1,2,4-oxadiazole core. Screening of an in-house collection containing 7500 compounds by ARE-luciferase reporter assay revealed a moderate Nrf2 activator, 1. Aimed at obtaining more derivatives efficiently, molecular similarity search by the combination of 2D fingerprint-based and 3D shape-based search was applied to virtually screening the Chemdiv collection. Three derivatives with the same core were identified to have better inductivity of Nrf2 than 1. The best hit 4 was selected as starting point for structurally optimization, leading to a much more potent derivative 32. It in vitro upregulated gene and protein level of Nrf2 as well as its downstream markers such as NQO1, GCLM, and HO-1. It remarkably suppressed inflammation in the in vivo LPS-challenged mouse model. Our results provide a new chemotype as Nrf2-ARE activators which deserve further optimization with the aim to obtain active anti-inflammatory agents through Nrf2-ARE pathway.

Effective screening strategy using ensembled pharmacophore models combined with cascade docking: application to p53-MDM2 interaction inhibitors.

Protein-protein interactions (PPIs) play a crucial role in cellular function and form the backbone of almost all biochemical processes. In recent years, protein-protein interaction inhibitors (PPIIs) have represented a treasure trove of potential new drug targets. Unfortunately, there are few successful drugs of PPIIs on the market. Structure-based pharmacophore (SBP) combined with docking has been demonstrated as a useful Virtual Screening (VS) strategy in drug development projects. However, the combination of target complexity and poor binding affinity prediction has thwarted the application of this strategy in the discovery of PPIIs. Here we report an effective VS strategy on p53-MDM2 PPI. First, we built a SBP model based on p53-MDM2 complex cocrystal structures. The model was then simplified by using a Receptor-Ligand complex-based pharmacophore model considering the critical binding features between MDM2 and its small molecular inhibitors. Cascade docking was subsequently applied to improve the hit rate. Based on this strategy, we performed VS on NCI and SPECS databases and successfully discovered 6 novel compounds from 15 hits with the best, compound 1 (NSC 5359), K(i) = 180 ± 50 nM. These compounds can serve as lead compounds for further optimization.