2,2',4,4',5,5'-Hexabromophenyl ether (BDE-153) causes abnormal insulin secretion and disorders of glucose and lipid metabolism in mice.

BACKGROUND: Environmental polybrominated diphenyl ether (PBDE) exposure may be associated with diabetes and obesity. 2,2',4,4',5,5'-Hexabromodiphenyl ether (BDE-153) is one of the most abundant and widely distributed homologs of PBDEs detected in humans. This study investigated the effects of BDE-153 on the expression of adipokines and glucose and lipid metabolism. METHODS: Adult male C57BL/6 mice were divided into five BDE-153 groups and one control group. After BDE-153 exposure for 4 weeks, the levels of biochemical indexes and the mRNA and protein expression levels of leptin, adiponectin, peroxisome proliferators activated receptors gamma (PPARγ), and AMPKα were measured. The histomorphological changes of liver and pancreas tissues were observed. RESULTS: After BDE-153 exposure, the weight of mice in the medium-high-dose group at different exposure times was lower than that in the control group ( p all <0.05), and the body weight decreased slightly with the increase of the dose of BDE-153. BDE-153 caused the disorder of glucose and lipid metabolism in mice, the weight of liver and pancreas increased, lipid droplets accumulated in liver cells, and the positive rate of insulin staining increased in a dose-dependent manner. BDE-153 also interfered with the expression of PPARγ, AMPKα, and adipokines. The results of restrictive cubic splines (RCS) showed that there were a nonlinear dose-response relationship between the exposure dose of BDE-153 and the expression levels of PPARγ, AMPKα, and adipokines. CONCLUSION: Our results suggest that BDE-153 may interfere with the expression of adipokines and the secretion of insulin by affecting the expression of PPARγ and AMPKα, which play a key role in glucose and lipid metabolism, leading to the occurrence of glucose and lipid metabolism disorder.

Bidirectional regulation of BDE-47 on 3T3-L1 cell differentiation based on a restricted cubic spline model.

BDE-47 (2,2,4,4-tetrabromodiphenyl ether) is a polybrominated diphenyl ether (PBDE) congener, which has the characteristics of high biological detection rate, the highest content and strong biological toxicity, and is widely distributed in organisms. Many studies have found that BDE-47 may also be an environmental risk factor for metabolic diseases such as obesity, insulin resistance, type 2 diabetes, and hypertension. However, the way that PBDEs influence adipocyte differentiation remains unclear. The methylisobutylxanthine, dexamethasone, and insulin method was used to study the effect of BDE-47 on the differentiation of 3T3-L1 cells. The 3T3-L1 cells were exposed by different concentrations of BDE-47, and the effect of cell viability was detected at different stages. In addition, the lipid droplet aggregation of adipocytes was observed and the triglyceride (TG) levels in the cytoplasm were detected after differentiation. The relative mRNA expression levels of leptin, adiponectin, and PPARγ in cells were determined by RT-PCR, and differentially expressed genes were preliminarily screened by digital gene expression profile. Our study found that BDE-47 promoted the differentiation of 3T3-L1 cells. Restriction cubic spline analysis showed that BDE-47 bidirectionally. regulated the mRNA synthesis of TG, PPARγ, and leptin genes and the aggregation of lipid droplets. BDE-47 may induce adipocyte differentiation by activating PPARγ, resulting in the differential expression of genes related to the AMPK signaling pathway, insulin resistance, and other metabolic pathways. The highest and lowest-dose BDE-47 exposure groups had the greatest impact on adipocyte differentiation.

The Cause of China's Haze Pollution: City Level Evidence Based on the Extended STIRPAT Model.

Based on the extended STIRPAT model, this paper examines social and economic factors regarding PM2.5 concentration intensity in 255 Chinese cities from 2007 to 2016, and includes quantile regressions to analyze the different effects of these factors among cities of various sizes. The results indicate that: (1) during 2007-2016, urban PM2.5 concentration exhibited declining trends in fluctuations concerning the development of the urban economy, accompanied by uncertainty under different city types; (2) population size has a significant effect on propelling PM2.5 concentration; (3) the effect of structure reformation on PM2.5 concentration is evident among cities with different populations and levels of economic development; and (4) foreign investment and scientific technology can significantly reduce PM2.5 emission concentration in cities. Accordingly, local governments not only endeavor to further control population size, but should implement a recycling economy, and devise a viable urban industrial structure. The city governance policies for PM2.5 concentration reduction require re-classification according to different population scales. Cities with large populations (i.e., over 10 million) should consider reducing their energy consumption. Medium population-sized cities (between 1 million and 10 million) should indeed implement effective population (density) control policies, while cities with small populations (less than 1 million) should focus on promoting sustainable urban development to stop environmental pollution from secondary industry sources.

Mapping and functional characterization of the tomato spotted wilt virus resistance gene SlCHS3 in Solanum lycopersicum.

Tomato spotted wilt virus (TSWV) poses a serious threat to tomato (Solanum lycopersicum) production. In this study, tomato inbred line YNAU335 was developed without the Sw-5 locus, which confers resistance or immunity to TSWV (absence of infection). Genetic analysis demonstrated that immunity to TSWV was controlled by a dominant nuclear gene. The candidate genes were mapped into a 20-kb region in the terminal of the long arm of chromosome 9 using bulk segregant analysis and linkage analysis. In this candidate region, a chalcone synthase-encoding gene (SlCHS3) was identified as a strong candidate gene for TSWV resistance. Silencing SlCHS3 reduced flavonoid synthesis, and SlCHS3 overexpression increased flavonoid content. The increase in flavonoids improved TSWV resistance in tomato. These findings indicate that SlCHS3 is indeed involved in the regulation of flavonoid synthesis and plays a significant role in TSWV resistance of YNAU335. This could provide new insights and lay the foundation for analyzing TSWV resistance mechanisms. Supplementary information: The online version contains supplementary material available at 10.1007/s11032-022-01325-5.

[Effects of decabromodiphenyl ether on glucose and lipid metabolism and adipocyte factors in C57BL/6 mice].

OBJECTIVE: To investigate the effect of decabromodiphenyl ether(BDE-209) on glucose and lipid metabolism and adipocytokines in mice. METHODS: A total of 36 adult male C57 BL/6 mice were randomly divided into 6 groups, 1000, 800, 600, 450 and 300 mg/kg groups and the control group, with 6 in each group. 60 days after gavage, fasting overnight, the mice were killed and the corresponding test materials were taken. Using an automatic biochemical analyzer to detect triglycerides(TG), total cholesterol(cholesterol, TC), low-density lipoprotein(LDL-C), and high-density lipoprotein(HDL-C). Detected rat fasting blood glucose(FBG) with Roche blood glucose meter. Observed the morphological changes of mouse liver tissue using HE staining. Determined leptin(LEP), the mRNA and protein expression levels of adiponectin(ADP) and peroxisome proliferators-activated receptors(PPAR)-γ with Real-time fluorescent quantitative PCR and Western blotting. RESULTS: The levels of fasting serum lisulin(FINS), insulin sensitivity index(ISI), ADP and HDL-C in the serum of the BDE-209 exposure group decreased(P& lt; 0. 05). The levels of FBG, LEP, TC, TG and LDL-C in the serum of the BDE-209 exposure group increased(P& lt; 0. 05). mRNA and protein expression levels of LEP and PPAR-γ in the liver increased(P& lt; 0. 05), and ADP mRNA and protein expression levels decreased(P& lt; 0. 05). Adipocyte factor LEP was positively correlated with the content of FBG, TG, TC and LDL-C, with r values of 0. 775, 0. 767, 0. 716 and 0. 812(P& lt; 0. 05), and negatively correlated with FINS and HDL-C, with r values of-0. 919 and-0. 817(P& lt; 0. 05). ADP was positively correlated with FINS and HDL-C, with r values of 0. 824 and 0. 832(P& lt; 0. 05), and negatively correlated with FBG, TG, TC and LDL-C, with r values of-0. 883, -0. 686, -0. 704 and-0. 772, respectively(P& lt; 0. 05). BDE-209 exposure to each dose group could change the morphology of mouse liver tissue to a certain extent. CONCLUSION: Decabromodiphenyl ether can disturb the metabolism of glucose and lipids. Among them, the disorder in the high and high dose groups of BDE-209 is more obvious. The low dose of BDE-209 can also change the morphology of liver tissue.

Two Tomato (Solanum lycopersicum) Thaumatin-Like Protein Genes Confer Enhanced Resistance to Late Blight (Phytophthora infestans).

Late blight (caused by Phytophthora infestans) poses a serious threat to tomato production but the number of late blight resistance genes isolated from tomato is limited, making resistance gene mining a high research priority. In this study, highly resistant CLN2037E and susceptible No. 5 tomato inbred lines were used to identify late blight resistance genes. Using transcriptome sequencing, we discovered 36 differentially expressed genes (DEGs), including 21 nucleotide binding site-leucine-rich repeat and 15 pathogenesis-related (PR) disease resistance genes. Cluster analysis and real-time quantitative PCR showed that these 36 genes possessed similar expression patterns in different inbred lines after inoculation with P. infestans. Moreover, two PR genes with unique responses were chosen to verify their functions when exposed to P. infestans: Solyc08g080660 and Solyc08g080670, both of which were thaumatin-like protein genes and were clustered in the tomato genome. Functions of these two genes were identified by gene overexpression and gene editing technology. Overexpression and knockout of single Solyc08g080660 and Solyc08g080670 corresponded to an increase and decrease in resistance to late blight, respectively, and Solyc08g080660 led to a greater change in disease resistance compared with Solyc08g080670. Cotransformation of dual genes resulted in a much greater effect than any single gene. This study provides novel candidate resistance genes for tomato breeding against late blight and insights into the interaction mechanisms between tomato and P. infestans.

Characterization of the DREBA4-Type Transcription Factor (SlDREBA4), Which Contributes to Heat Tolerance in Tomatoes.

Dehydration-responsive element binding (DREB) transcription factors play crucial regulatory roles in abiotic stress. The only DREB transcription factor in tomato (Solanum lycopersicum), SlDREBA4 (Accession No. MN197531), which was determined to be a DREBA4 subfamily member, was isolated from cv. Microtom using high-temperature-induced digital gene expression (DGE) profiling technology. The constitutive expression of SlDREBA4 was detected in different tissues of Microtom plants. In addition to responding to high temperature, SlDREBA4 was up-regulated after exposure to abscisic acid (ABA), cold, drought and high-salt conditions. Transgenic overexpression and silencing systems revealed that SlDREBA4 could alter the resistance of transgenic Microtom plants to heat stress by altering the content of osmolytes and stress hormones, and the activities of antioxidant enzymes at the physiologic level. Moreover, SlDREBA4 regulated the downstream gene expression of many heat shock proteins (Hsp), as well as calcium-binding protein enriched in the pathways of protein processing in endoplasmic reticulum (ko04141) and plant-pathogen interaction (ko04626) at the molecular level. SlDREBA4 also induces the expression of biosynthesis genes in jasmonic acid (JA), salicylic acid (SA), and ethylene (ETH), and specifically binds to the DRE elements (core sequence, A/GCCGAC) of the Hsp genes downstream from SlDREBA4. This study provides new genetic resources and rationales for tomato heat-tolerance breeding and the heat-related regulatory mechanisms of DREBs.