Avermectin induced vascular damage in zebrafish larvae: association with mitochondria-mediated apoptosis and VEGF/Notch signaling pathway.

Avermectin is a highly effective insecticide that has been widely used in agriculture since the 1990s. In recent years, the safety of avermectin for non-target organisms has received much attention. The vasculature is important organs in the body and participate in the composition of other organs. However, studies on the vascular safety of avermectin are lacking. The vasculature of zebrafish larvae is characterized by ease of observation and it is a commonly used model for vascular studies. Therefore, zebrafish larvae were used to explore the potential risk of avermectin on the vasculature. The results showed that avermectin induced vascular damage throughout the body of zebrafish larvae, including the head, eyes, intestine, somite, tail and other vasculature. The main forms of damage are reduction in vascular diameter, vascular area and vascular abundance. Meanwhile, avermectin induced a decrease in the number of endothelial cells and apoptosis within the vasculature. In addition, vascular damage may be related to impairment of mitochondrial function and mitochondria-mediated apoptosis. Finally, exploration of the molecular mechanisms revealed abnormal alterations in the expression of genes related to the VEGF/Notch signaling pathway. Therefore, the VEGF/Notch signaling pathway may be an important mechanism for avermectin-induced vascular damage in zebrafish larvae. This study demonstrates the vascular toxicity of avermectin in zebrafish larvae and reveals the possible molecular mechanism, which would hopefully draw more attention to the safety of avermectin in non-target organisms.

Mechanisms Underlying the Overlooked Chiral Fungicide-Driven Enantioselective Proliferation of Antibiotic Resistance in Earthworm Intestinal Microbiome.

From a "One Health" perspective, the global threat of antibiotic resistance genes (ARGs) is associated with modern agriculture practices including agrochemicals application. Chiral fungicides account for a considerable proportion of wildly used agrochemicals; however, whether and how their enantiomers lead to differential proliferation of antibiotic resistance in agricultural environments remain overlooked. Focused on the soil-earthworm ecosystem, we for the first time deciphered the mechanisms underlying the enantioselective proliferation of antibiotic resistance driven by the enantiomers of a typical chiral fungicide mandipropamid (i.e., R-MDP and S-MDP) utilizing a multiomic approach. Time-series metagenomic analysis revealed that R-MDP led to a significant enhancement of ARGs with potential mobility (particularly the plasmid-borne ARGs) in the earthworm intestinal microbiome. We further demonstrated that R-MDP induced a concentration-dependent facilitation of plasmid-mediated ARG transfer among microbes. In addition, transcriptomic analysis with verification identified the key aspects involved, where R-MDP enhanced cell membrane permeability, transfer ability, biofilm formation and quorum sensing, rebalanced energy production, and decreased cell mobility versus S-MDP. Overall, the findings provide novel insights into the enantioselective disruption of microbiome and resistome in earthworm gut by chiral fungicides and offer significant contributions to the comprehensive risk assessment of chiral agrochemicals in agroecosystems.

Simultaneous Detection of Multiple Plant Growth Regulator Residues in Cabbage and Grape Using an Optimal QuEChERS Sample Preparation and UHPLC-MS/MS Method.

BACKGROUND: At present, plant growth regulators (PGRs) are widely used in agricultural and forestry production. PGRs, like traditional pesticides, have certain toxicities. Naively excessively applying them will cause the acute and chronic poisoning of humans and animals and potentially harm human health. OBJECTIVE: In order to assess, prevent, and control the residues of PGRs in fruits and vegetables, a set of quick, easy, cheap, effective, rugged, and safe (QuEChERS) analytical methods that simultaneously detect multiple PGR residues are urgently needed for quality and safety inspection of agricultural product. METHODS: In this study, grapes (representative of fruits) and cabbages (representative of vegetables) were used as the detected objects. The 30 commercial product residues of PGRs were detected in both with an ultra-high performance liquid chromatography (UHPLC)-tandem mass spectrometry (MS/MS) method, based on optimized chromatographic, MS, and preparation conditions (extraction solvent and cleanup conditions). Grape and cabbage samples were extracted with acetonitrile containing 5% (v/v) acetic acid, dehydrated using a salt package, purified using the QuEChERS method, ionized using electrospray ionization under positive and negative ion switching mode, detected using multi-reaction monitoring, and quantification using an external standard method of matrix matching standard curve. RESULTS: Methanol was selected as the strong elution phase. A methanol-0.1% formic acid-5 mmol/L ammonium acetate solution was selected as the best mobile phase. The optimal extraction solvent was acetonitrile containing 5% acetic acid. Primary secondary amine cleanup could met the determination requirements of PGR residues. The developed method for determination of 30 commercial products of PGR, such as betaine, showed excellent linearity in 1-500, 10-1000, ∼500, ∼2000, and 100-10 000 µg/kg (R ≥ 0.98). At the 0.001 (0.01), 0.05, 0.20, and 1.00 mg/kg additive concentrations, the average addition standard recovery of 30 commercial products of PGR were 61-132% with the relative standard deviations of 1-14% and the LOQs were confirmed to be 1.0-100 µg/kg through the actual addition values of samples. CONCLUSION: The set of optimized QuEChERS UHPLC-MS/MS methods simultaneously detect residues of PGRs in fruits and vegetables with one-time sample preparation for high-throughput, rapid quantitative screening, and confirmation. The methods cover a wide range of PGRs with simple and convenient preparation and small amounts of solvent, and can provide technical support for the supervision of PGR residues in fruits and vegetables. HIGHLIGHTS: The optimizations of extraction solvent screening, different ratios of various purification packages in the QuEChERS method, and UPLC-MS conditions were conducted and the precision, sensitivity, and recovery rates of the methods were investigated in order to establish a QuEChERS UPLC-MS/MS method for simultaneously detecting 30 kinds of PGR residues in fruits and vegetables. The methods allow high-throughput determination of multiple PGR residues in fruits and vegetables and can also provide technical references for related compound residue detection of other matrixes.

[Investigation of organophosphorous insecticides residue in Chinese crude drugs].

OBJECTIVE: To study eleven organophosphorus insecticides residuals in four kinds of Chinese crude drugs. METHOD: The organophosphorus insecticides were extracted with dichloromethane and cleaned-up with a mixture of Celite 545-activated carbon. The extracts were analyzed by gas chromatography equipped with a flame photometric detector (FPD). RESULT: Analysis of fortified Chinese crude drug showed that the average recoveries ranged from 77.5% -112.3% at three different levels, the RSDs were below 10% (n = 4). Trace organophosphorous pesticide residues were found in samples of Rhizoma Atractylodis Macrocephalae and Flos Chrysanthemi. CONCLUSION: A method was established for determination multi-residues in Rhizma Atractylodis Macrocephalae, Radix Curcumae, Bulbus Fritillariae Thunbergii and Flos Chrysanthemi. It provides a method for the risk assessment of organophosphorous pesticide in Chinese crude drugs.

[Ectogenous fragile histidine triad gene inhibits the malignant phenotype of human lung cancer cell line A549 in vitro and in vivo].

OBJECTIVE: To investigate the inhibition effects of fragile histidine triad (FHIT) gene on the malignant growth of A549 cell line. METHODS: A mammalian expression vector PEGFP-FHIT was constructed and transfected into the A549 cell line by lipofectamine. Then the transfected cell line was screened by G418. Individual G418-resistant colonies were isolated by limited dilution. The monoclonal transfected cell line was screened by RT-PCR and immunochemical staining. The inhibition growth efficacy of extraneous FHIT was evaluated by clonogenic survival assay, flow cytometry and heteroplastic transplant on nude mice. RESULTS: Presence of extraneous FHIT gene in FHIT-A549 cell was proved by RT-PCR. Immunochemical stain demonstrated that the expression of extraneous FHIT protein was positive in FHIT-A549 cell and negative in PEGFP-A549 cell and A549 cell. The clonal formation rate of FHIT-A549 (2.6%) was significantly lower than that of A549 cell (50.1%) and PEGFP-A549 cell (53.6%, P < 0.01). FHIT-A549 cell (95.8%) was blocked in G(2) phage. Tumorigenicity of A549 cells in nude mice was greatly inhibited by expression of ectogenous FHIT gene. The weight of tumor was significantly lower in FHIT-A549 cell (0.04 +/- 0.03) than in A549 cell (0.24 +/- 0.11) and PEGFP-A549 cell (0.25 +/- 0.07, P < 0.01). CONCLUSIONS: Reintroduction of the expression of ectogeneous FHIT gene can obviously suppress the proliferation and tumorigenicity in human lung cancer cell line A549 and induce apoptosis. The data demonstrate oncosuppressive properties of FHIT gene.

[The relationship between genetic polymorphism of metabolizing enzymes and the genetic susceptibility to lung cancer].

OBJECTIVE: To investigate the relationship between the gene polymorphism of metabolizing enzymes and the genetic susceptibility to lung cancer as well as to study the synergistic effects between smoking and the genes. METHODS: A case-control study (case = 217, control = 200) was carried out to compare the frequent distribution of CYP1A1, 2E1, 2D6 and GSTM1 genotypes between the lung cancer group and the control group with a polymerase chain reaction-restriction fragment polymorphism (PCR-RFLP) method and to analyze the relationship between these genes and smoking. RESULTS: GSTM1-null genotype frequency was 58.5% in the lung cancer group and 47.5% in the control group with significant difference (P = 0.02). The frequent distribution of CYP1A1, 2E1, 2D6 genotypes was not significantly different in the two groups (P > 0.05). Synergistic effects were found between smoking and GSTM1 but not between smoking and CYP1A1, 2E1, 2D6. CONCLUSION: Smoking and GSTM1-null genotype seemed to be the risk factors of lung cancer. Those who carrying GSTM1-null genotype and smoking cigarettes were prone to suffer from lung cancer to become the high-risk population of the disease.

[Inhibitory effect of p53 with deletion of c-terminal 356 - 393 amino acids on malignant phenotype of human lung cancer cell line].

OBJECTIVE: To study the effect of extraneous p53 gene with deletion of c-terminal 356 - 393 amino acids on inhibition of malignant phenotype of human lung cancer cell line. METHODS: Recombinant plasmid pEGFP-p53 (del) with codon deletion of c-terminal 37 amino acids from 393 to 356 region and pEGFP-p53 (wild type) were constructed. The human lung cancer cell line 801D served as a receipt cell had p53 deletion and mutation at 248 codon. 801D cells, having been transfected by pEGFP-p53 (wild type), pEGFP-p53 (del) or pEGFP, were selected by G418. Growing transfected cells were cloned respectively by method of dilution. Presence of extraneous gene was detected by PCR, their expression in cells was examined by fluorescence microscopy. Cloning efficiency was in vitro tested to examine the cellular proliferating ability. The xenograft in nude mice was performed and xenograft tumors were weighed one month later. Expression of GFP in tumor and transplanted cellular mass were detected by blot slices. RESULTS: pEGFP-p53 (del)-801D, pEGFP-p53-801D and pEGFP-801D were established. Extraneous p53 gene and expression of GFP were found in pEGFP-p53 (del)-801D and pEGFP-p53-801D. Inhibitory rate of colony was 99.6% for pEGFP-p53 (del)-801D and 81.0% for pEGFP-p53-801D. Inhibition of malignant proliferation of extraneous p53 (del) was higher than that of p53 (wild type) (P < 0.01). Even when inhibition of malignant proliferation extraneous pEGFP-p53 (del) was obvious, 0.2% colonies were formed, extraneous p53 and expression of GFP were observed. Animal test showed that tumor on the nude mice was positive (4/4, 4/4) in the control group (801D and pEGFP-801D), but negative (0/4, 0/4) in the experiment group [pEGFP-p53 (del) 801D and pEGFP-p53 (wild type) 801D]. Expression of GFP in the cells of cellular mass transplanted by pEGFP-p53 (del) 801D or pEGFP-p53 (wild type) 801D was observed. CONCLUSION: In vitro inhibitory effect of extraneous p53 gene with deletion of C-terminal 356 - 393 amino acids on malignant growth of lung cancer cell with p53 mutation or deletion at 248 codon is marked. Inhibitory action of p53 on malignant proliferation of cancer cells is heterogeneous.