Study on the Distribution of Low Molecular Weight Metabolites in Mango Fruit by Air Flow-Assisted Ionization Mass Spectrometry Imaging.

Mass spectrometry imaging is a novel molecular imaging technique that has been developing rapidly in recent years. Air flow-assisted ionization mass spectrometry imaging (AFAI-MSI) has received wide attention in the biomedical field because of its features such as not needing a pretreatment sample, having high sensitivity, and wide coverage of metabolite detection. In this study, we set up a mass spectrometry imaging method for analyzing low molecular metabolites in mango fruits by the AFAI-MSI method. Compounds such as organic acids, vitamin C, and phenols were detected from mango tissue by mass spectrometry under the negative ion scanning mode, and their spatial distribution was analyzed. As a result, all the target compounds showed different distributions. Citric acid was mainly distributed in the pulp. Malic acid, quinic acid, and vitamin C universally existed in the pulp and peel. However, galloylglucose isomer and 5-galloylquinic acid were predominantly found in the peel. These results show that AFAI-MSI can be used for the analysis of mango fruit endogenous metabolites conveniently and directly, which will facilitate the rapid identification and in situ characterization of plant endogenous substances.

Breviscapine alleviates myocardial ischemia-reperfusion injury in diabetes rats.

PURPOSE: To investigate the protective effect of breviscapine on myocardial ischemia-reperfusion injury (MIRI) in diabetes rats. METHODS: Forty rats were divided into control, diabetes, MIRI of diabetes, and treatment groups. The MIRI of diabetes model was established in the latter two groups. Then, the treatment group was treated with 100 mg/kg breviscapine by intraperitoneal injection for 14 consecutive days. RESULTS: After treatment, compared with MIRI of diabetes group, in treatment group the serum fasting blood glucose, fasting insulin, homeostasis model assessment of insulin resistance, and glycosylated hemoglobin levels decreased, the serum total cholesterol, triacylglycerol, and low-density lipoprotein cholesterol levels decreased, the serum high-density lipoprotein cholesterol level increased, the heart rate decreased, the mean arterial pressure, left ventricular ejection fraction, and fractional shortening increased, the serum cardiac troponin I, and creatine kinase-MB levels decreased, the myocardial tumor necrosis factor α and interleukin-6 levels decreased, the myocardial superoxide dismutase level increased, and the myocardial malondialdehyde level decreased (all P < 0.05). CONCLUSIONS: For treating MIRI of diabetes in rats, the breviscapine can reduce the blood glucose and lipid levels, improve the cardiac function, reduce the myocardial injury, and decrease the inflammatory response and oxidative stress, thus exerting the alleviating effect.

Two types of coumarins-specific enzymes complete the last missing steps in pyran- and furanocoumarins biosynthesis.

Pyran- and furanocoumarins are key representatives of tetrahydropyrans and tetrahydrofurans, respectively, exhibiting diverse physiological and medical bioactivities. However, the biosynthetic mechanisms for their core structures remain poorly understood. Here we combined multiomics analyses of biosynthetic enzymes in Peucedanum praeruptorum and in vitro functional verification and identified two types of key enzymes critical for pyran and furan ring biosynthesis in plants. These included three distinct P. praeruptorum prenyltransferases (PpPT1-3) responsible for the prenylation of the simple coumarin skeleton 7 into linear or angular precursors, and two novel CYP450 cyclases (PpDC and PpOC) crucial for the cyclization of the linear/angular precursors into either tetrahydropyran or tetrahydrofuran scaffolds. Biochemical analyses of cyclases indicated that acid/base-assisted epoxide ring opening contributed to the enzyme-catalyzed tetrahydropyran and tetrahydrofuran ring refactoring. The possible acid/base-assisted catalytic mechanisms of the identified cyclases were theoretically investigated and assessed using site-specific mutagenesis. We identified two possible acidic amino acids Glu303 in PpDC and Asp301 in PpOC as vital in the catalytic process. This study provides new enzymatic tools in the epoxide formation/epoxide-opening mediated cascade reaction and exemplifies how plants become chemically diverse in terms of enzyme function and catalytic process.

Cellulose Hollow Annular Nanoparticles Prepared from High-Intensity Ultrasonic Treatment.

Cellulose nanomaterials, such as cellulose nanocrystals (CNCs), have received enormous attention in various material research fields due to their unique properties and green/sustainable nature, among other qualities. Herein, we report hollow-type annular cellulose nanocrystals (HTA-CNCs), which are generated by following a high-intensity ultrasonic treatment. The advanced aberration-corrected transmission electron microscopy results reveal that HTA-CNCs exhibit ring structures with a typical diameter of 10.0-30.0 nm, a width of 3.0-4.0 nm, and a thickness of 2.0-5.0 nm, similar to those of elementary crystallites. The X-ray diffraction measurements show that the as-prepared HTA-CNCs maintain the cellulose I structure. The changes in structure and hydrogen-bonding characteristics of HTA-CNCs are further determined based on the FT-IR results after deconvolution fitting, showing that three types of hydrogen bonds decrease and the content of free OH increases in HTA-CNCs compared with those in the original CNCs. Furthermore, molecular dynamics simulation is carried out to support the experimental study. The formation of HTA-CNCs might be attributed to the structural change and entropy increase. The hollow-type annular CNCs may have broad value-added applications as cellulose nanomaterials in different fields.

Effects of S100 calcium-binding protein A8 (S100A8) and S100 calcium-binding protein A9 (S100A9) on matrix metalloproteinase (MMP) expression in nasopharyngeal carcinoma CNE-2 cells.

BACKGROUND: Studies have shown that S100A8 and S100A9 are highly expressed in a variety of tumors, including NPC, and are associated with tumor invasion and migration. MMPs are associated with the invasion and migration of tumor cells. To further investigate the mechanism by which S100A8 and S100A9 affect the invasion and migration of NPC cells, the present study examined the effects of S100A8 and S100A9 on MMPs in NPC CNE-2 cells. METHODS: Recombinant pEGFP-N1-S100A8 and recombinant pEGFP-N1-S100A9 overexpression vectors and S100A8 and S100A9 RNA interference (RNAi) vectors were constructed and transfected into NPC CNE-2 cells. The transfection efficiency in each group of cells was assessed, and the gene and protein expression of MMP7, MMP9 and MMP12 were determined. RESULTS: The transfection efficiency was approximately 60-70%. Compared with those in the control group, the expression levels of MMP7, MMP9 and MMP12 in the S100A8 and S100A9 overexpression groups was significantly higher (P<0.05), and the expression levels of MMP7, MMP9 and MMP12 in the S100A8-RNAi and S100A9-RNAi groups were significantly lower (P<0.05). The number of cells in S100A8 overexpression group and S100A9 overexpression group at 24, 48 and 72 h was higher than that in RNAi group, RNAi control group, overexpression control group and normal control group, with statistical significance; The cell doubling time in S100A8 and S100A9 overexpression group was significantly shorter than that in RNAi control group, overexpression control group and normal control group, with statistical significance. CONCLUSIONS: High S100A8 and S100A9 expression may promote the expression of MMP7, MMP9 and MMP12, which are related to the invasion and metastasis of NPC cells.

Breviscapine alleviates myocardial ischemia-reperfusion injury in diabetes rats

Purpose: To investigate the protective effect of breviscapine on myocardial ischemia-reperfusion injury (MIRI) in diabetes rats. Methods: Forty rats were divided into control, diabetes, MIRI of diabetes, and treatment groups. The MIRI of diabetes model was established in the latter two groups. Then, the treatment group was treated with 100 mg/kg breviscapine by intraperitoneal injection for 14 consecutive days. Results: After treatment, compared with MIRI of diabetes group, in treatment group the serum fasting blood glucose, fasting insulin, homeostasis model assessment of insulin resistance, and glycosylated hemoglobin levels decreased, the serum total cholesterol, triacylglycerol, and low-density lipoprotein cholesterol levels decreased, the serum high-density lipoprotein cholesterol level increased, the heart rate decreased, the mean arterial pressure, left ventricular ejection fraction, and fractional shortening increased, the serum cardiac troponin I, and creatine kinase-MB levels decreased, the myocardial tumor necrosis factor α and interleukin-6 levels decreased, the myocardial superoxide dismutase level increased, and the myocardial malondialdehyde level decreased (all P < 0.05). Conclusions: For treating MIRI of diabetes in rats, the breviscapine can reduce the blood glucose and lipid levels, improve the cardiac function, reduce the myocardial injury, and decrease the inflammatory response and oxidative stress, thus exerting the alleviating effect.

Exploring structural variations of hydrogen-bonding patterns in cellulose during mechanical pulp refining of tobacco stems.

Hydrogen bonding and mechanical refining are closely correlated. In this work, structural variations of hydrogen bonding patterns in cellulose during mechanical pulp refining, including the hydrogen bonding energy and distance as well as the content of hydrogen bonds, have been explored by using the second derivative FTIR spectra and deconvolving spectra in the OH stretching vibrational region. Results show that except for the bond distance, both the hydrogen bonding energy and the content of hydrogen bonds exhibit a significant variation at an increasing beating degree. The calculated hydrogen bonding energies for intermolecular O6H⋯O3' decrease by 12.9%, while those of intramolecular O3H⋯O5 and O2H⋯O6 vary little. Evolutions of the content of certain hydrogen bonds differ depending on the different refining stage. It is suggested that along with the role of water, hydration and swelling, internal/external fibrillation and delamination are strongly related to the structural variations of hydrogen bonding patterns in cellulose during mechanical pulp refining.

Exploring crystalline structural variations of cellulose during pulp beating of tobacco stems.

In this work, crystalline structural variations of cellulose during pulp beating of tobacco stems were characterized through X-ray diffraction (XRD) and FT-IR spectroscopy. The results showed that the correlation between the cellulose crystallinity index and the degree of beating was not a linear but an initially upward and then downward trend followed by a repeating fluctuation as a result of the beating action on amorphous regions first and then on crystalline cellulose. It was proposed that the whole beating process might be presumably divided into two phases in the case of the evolution of the crystallinity index. The crystallite sizes of 101 and 101¯ lattice planes showed an obvious fluctuation during the beating while the crystallite sizes and d-spacings from representative 002 lattice planes exhibited little change. Complementally, FT-IR characterization of cellulose structural properties further proved that the crystallinity index was highly affected by mechanical beating and the intact beating process might be divided into two stages characteristic of a first ascending and then descending tendency.

Measuring the Gap: A Health Assessment of Rural Chinese Children Compared to Urban Children.

China is a large country where rapid development is accompanied by growing inequalities. How economic inequalities translate to health inequalities is unknown. Baseline health assessment is lacking among rural Chinese children. We aimed at assessing baseline student health of rural Chinese children and comparing them with those of urban children of similar ages. A cross-sectional study was conducted using the 2003 Global School-Based Student Health Survey among 100 students Grade 4 to 6 from rural Guizhou, China. Results were summarized and compared with public data from urban Beijing using multivariate logistic regression models. Rural children are more likely to not wash their hands before a meal (odds ratio [OR] = 5.71, P < .01) and after using the toilet (OR = 5.41, P < .01). They are more likely to feel sick or to get into trouble after drinking (OR = 7.28, P < .01). They are more likely to have used drugs (OR = 8.54, P < .01) and to have no close friends (OR = 8.23, P < .01). An alarming percentage of rural (8.22%) and urban (14.22%) children have had suicidal ideation in the past year (OR = 0.68, P > .05). Rural parents are more likely to not know their children's whereabouts (OR = 1.81, P < .05). Rural children are more than 4 times likely to have serious injuries (OR = 4.64, P < .01) and to be bullied (OR = 4.01, P < .01). In conclusion, school-age rural Chinese children exhibit more health risk behaviors and fewer protective factors at baseline compared to their urban counterparts. Any intervention aimed at improving child health should take this distributive gap into consideration.

Recombinant human neuregulin-1ß is protective against radiation-induced myocardial cell injury.

The aim of the present study was to investigate the role of recombinant human neuregulin-1ß (rhNRG-1ß) in the repair of the radiation-induced damage of myocardial cells and the underlying mechanism. Rats were divided into the radiotherapy alone group, the rhNRG-1ß group (radiotherapy with rhNRG­1ß treatment) and the Herceptin group (radiotherapy with Herceptin treatment), and their myocardial cells were analyzed. The morphology of the myocardial cells was observed under an optical microscope, and the expression of γ­H2AX and p53 was analyzed using immunohistochemistry and western blot analysis. Damage to the myocardial cells was identified in the three groups following radiation treatment, which was identified by cell swelling and altered morphology. The integrated optical density values of γ­H2AX in the radiotherapy alone, rhNRG­1ß and Herceptin groups were 50.96±5.548, 27.63±10.61 and 76.12±2.084, respectively. The OD of the radiotherapy alone group was significantly higher than that of the rhNRG­1ß treated group (P<0.0001), and the value of the Herceptin group was significantly higher than that of the radiotherapy alone group (P<0.0001). The p53 level in the rhNRG­1ß group was less than that of the radiotherapy alone group (P<0.001), and was higher in the Herceptin group compared with the radiotherapy alone group (P<0.0001). Thus, rhNRG­1ß can ameliorate radiotherapy-induced myocardial cell injury, predominantly by enhancing myocardial cell DNA repair, inhibiting cell apoptosis and improving myocardial function. The results of this study in myocardial cells suggest that patients with thoracic cancer may benefit from treatment with rhNRG­1ß for the repair of the radiation-induced damage of myocardial cells.

Releasing nitrogen from ammoniated lignin by white rot fungus cometabolizes environmental pollutants.

The nitrogen-modified lignocelluloses(NML) produced under oxic ammoniation was metabolized by white rot fungus, NH4(+) -N was released, NO3(-) -N concentration was decreased and total nitrogen loss was blocked within incubation period. During releasing nitrogen from the metabolism of NML, white rot fungus cometabolized recalcitrant environmental pollutants and showed higher degradation capability. Results indicated that this NML complex colonized by white rot fungus might be effective with economic feasibility when they are applied into the vast field ecosystem, it might stabilize NH4+ nitrogen flux and bioremediate the polluted environmental sites.