Search

Fine particulate matter (PM 2.5) exposure is strongly associated with vascular endothelial senescence, a process implicated in cardiovascular diseases. While there is existing knowledge on the impact of Lycium barbarum polysaccharide (LBP) on vascular endothelial damage, the protective mechanism of LBP against PM 2.5 -induced vascular endothelial senescence remains unclear. In this study, we investigated the impact of PM 2.5 exposure on vascular endothelial senescence and explored the intervention effects of LBP in human umbilical vein endothelial cells (HUVECs). We found that PM 2.5 exposure dose-dependently reduced cell viability and proliferation in HUVECs while increasing the production of reactive oxygen species (ROS), malondialdehyde (MDA), and hydrogen peroxide (H 2 O 2). Additionally, PM 2.5 exposure inhibited the activity of superoxide dismutase (SOD). Notably, PM 2.5 exposure induced autophagy impairments and cellular senescence. However, LBP mitigated PM 2.5 -induced cell damage. Further studies demonstrated that correcting autophagy impairment in HUVECs reduced the expression of the senescence markers P16 and P21 induced by PM 2.5. This suggests the regulatory role of autophagy in cellular senescence and the potential of LBP in improving HUVECs senescence. These findings provide novel insights into the mechanisms underlying PM 2.5 -induced cardiovascular toxicity and highlight the potential of LBP as a therapeutic agent for improving vascular endothelial health. • Exposure to PM 2.5 leads to damage and senecence of HUVECs. • Senescence of HUVECs is associated with PM 2.5 -induced autophagy impairment. • Lycium barbarum polysaccharides inhibited cell senescence induced by PM 2.5. [ABSTRACT FROM AUTHOR]

In this study, we aimed to identify potentially different lipids in ripe peaches with different textures through a comprehensive, quantitative lipidomic analysis using LC-MS/MS. By analyzing 27 different cultivars, we detected 282 lipid species across 23 subclasses, including 118 significantly different lipids (DLs) among the different fruit texture groups. Lipids primarily consist of fatty acyls, followed by glycerophospholipids, glycerolipids, sphingolipids, and sterol lipids. PCA and OPLS-DA analyses demonstrated that peach fruit lipids differed significantly depending on flesh texture. Four phosphatidylethanolamines, three phosphatidylcholines, one lysophosphatidylethanolamine, one sterol ester, one sterol glycoside, and four ceramides were highly correlated with peach flesh firmness, crispness, and compactness. Glycerolipid and glycerophospholipid metabolism are the most prominent metabolic pathways for DLs, followed by sphingolipid and inositol phosphate metabolism. Our study helps identify novel targets for fruit texture improvement and provides new perspectives on the regulation of peach storage and transportation quality. • 282 lipids from 23 subclasses were quantified in the fruit of 27 peach cultivars. • Peach fruit lipids differ significantly depending on flesh texture. • A total of 118 significantly different lipids (DLs) between groups were identified. • Specific lipids correlated with peach flesh firmness, crispness, and compactness. • Glycerolipid and glycerophospholipid metabolism pathways dominate in the DLs. [ABSTRACT FROM AUTHOR]

Abstract: Recent research has highlighted the presence of Toll/Interleukin 1 receptor (TIR)-domain proteins (Tdps) in a range of bacteria, suggested to form interactions with the human adaptor protein MyD88 and inhibit intracellular signaling from Toll-like receptors (TLRs). A Tdp has been identified in Yersinia pestis (YpTdp), a highly pathogenic bacterium responsible for plague. Expression of a number of YpTIR constructs of differing lengths (YpTIR1, S130-A285; YpTIR2, I137-I273; YpTIR3, I137-246; YpTIR4, D107-S281) as fusions with an N-terminal GB1 tag (the B1 immunoglobulin domain of Streptococcal protein G) yielded high levels of soluble protein. Subsequent purification yielded 4–6 mg/L pure, folded protein. Thrombin cleavage allowed separation of the GB1 tag from YpTIR4 resulting in folded protein after cleavage. Nuclear magnetic resonance spectroscopy, size exclusion chromatography, SDS-PAGE analysis and static light scattering all indicate that the YpTIR forms dimers. Generation of a double Cys-less mutant resulted in an unstable protein containing mainly monomers indicating the importance of disulphide bonds in dimer formation. In addition, the YpTIR constructs have been shown to interact with the human adaptor protein MyD88 using 2D NMR and GST pull down. YpTIR is an excellent candidate for further study of the mechanism of action of pathogenic bacterial Tdps. [Copyright &y& Elsevier]

The effects of 1-methylcyclopropene (1-MCP) on the sensory quality of the 'Yulu' flat peach fruit were determined using electronic tongue, electronic nose, LC-MS/MS, and HS-SPME-GC-MS. A total of 90 taste compounds and 49 volatile compounds were quantified. Of these, 15–21 types of aroma compounds with odor activity values (OAV) > 1 were considered as the most significant volatiles. 1-MCP significantly affected the levels of soluble sugars, organic acids, free amino acids, phenolics, amygdalin, and volatile compounds. 1-MCP slowed the increase in alanine and γ-aminobutyric acid in fruit during ripening and senescence. 1-MCP also increased the level of proline in fruits, and decreased that of glutamic acid, glutamine, and serine. 1-MCP significantly inhibited the decline in procyanidins after six to ten days of storage. During fruit senescence, the level of free esters markedly increased; however, 1-MCP reduced this level. Fruits treated with 1-MCP contained more β-myrcene and linalool and fewer lactones. β-Damascenone, (E)-2-nonenal, (E)-2-hexenal, γ-decalactone had the highest OAVs. The PCA biplot revealed that fruit shelf-life duration had a greater effect on taste than 1-MCP, while 1-MCP had a greater impact on aroma. Our findings provide a basis for the use of 1-MCP to preserve flat peaches in the future. • Taste and aroma were profiled by electronic senses, LC-MS/MS, and HS-SPME-GC-MS. • Fruit shelf-life duration had a greater effect on taste than 1-methylcyclopropene (1-MCP). • Flavor-related primary and secondary metabolites in fruits were markedly affected by 1-MCP. • 1-MCP had a greater effect on aroma than taste. [ABSTRACT FROM AUTHOR]

Free amino acids (FAAs) are essential for fruit flavor and function. In this study, mature fruits of 129 germplasms grown in China were employed to fully comprehend the variability in the FAA composition of peaches (Prunus persica (L.) Batsch). A brief sample preparation process, based on formic acid/water/methanol extraction, was performed. Using the HSS T3 column, 24 FAAs were successfully separated. These FAAs were analyzed using LC-MS/MS without derivatization. A total of 20 FAAs were detected in peaches. Asparagine was the most abundant FAA (368.04–6090.79 μg/g FW) in peach fruit, followed by aspartic acid (29.00–409.51 μg/g FW), glutamic acid (45.33–290.13 μg/g FW), alanine (22.39–805.21 μg/g FW), glutamine (12.05–322.62 μg/g FW), serine (17.81–323.35 μg/g FW), and threonine (10.9–109.04 μg/g FW). Other proteinaceous amino acids, including arginine, glycine, histidine, isoleucine, leucine, lysine, phenylalanine, proline, tryptophan, tyrosine, valine, cis-4-hydroxy-proline, and a specialized non-proteinaceous amino acid, γ-aminobutyric acid, were identified and quantified in the peach germplasm. By comparing the FAA content of various germplasms, middle- and late- maturing peaches were found to possess more asparagine, proline, and cis-4-hydroxy-proline than early-maturing peaches. These essential results could markedly augment peach breeding programs and provide a comprehensive understanding of the peach germplasm resources. • Analytical procedure without derivatization step using RPLC–MS/MS was developed. • FAA samples were easily prepared with formic acid/water/methanol solution. • There are significant differences in the FAA content of the 129 peach germplasm resources. • Mid- and late-maturing peaches has higher levels of Asn, Pro, and 4-OH-Pro. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are short non-coding RNA and play crucial roles in a wide array of biological processes, including cell proliferation, differentiation and apoptosis. Our previous studies found that homocysteine(Hcy) can stimulate the proliferation of vascular smooth muscle cells (VSMCs), however, the underlying mechanisms were not fully elucidated. Here, we found proliferation of VSMCs induced by Hcy was of correspondence to the miR-125b expression reduced both in vitro and in the ApoE knockout mice, the hypermethylation of p53, its decreased expression, and DNA (cytosine-5)-methyltransferase 3b (DNMT3b) up-regulated. And, we found DNMT3b is a target of miR-125b, which was verified by the Dual-Luciferase reporter assay and western blotting. Besides, the siRNA interference for DNMT3b significantly decreased the methylation level of p53, which unveiled the causative role of DNMT3b in p53 hypermethylation. miR-125b transfection further confirmed its regulative roles on p53 gene methylation status and the VSMCs proliferation. Our data suggested that a miR-125b-DNMT3b-p53 signal pathway may exist in the VSMCs proliferation induced by Hcy. [ABSTRACT FROM AUTHOR]

Abstract: Three-dimensional polyacrylamide gel microarray (3-D gel microarray) has a strong adsorption for hybridzation probes with fluorescent label, resulting in high fluorescent background noise. The background noise has hampered the broad application of the microarray in scientific research. A low-frequency ultrasound of 40kHz has been successfully employed to efficiently remove the nonspecifically bound fluorescent probes from the 3-D gel microarray. The method can significantly enhance the signal to noise ratio of the 3-D gel microarray and make it work better in single-nucleotide polymorphism genotyping. [Copyright &y& Elsevier]