Renoprotection of Microcystin-RR in Unilateral Ureteral Obstruction-Induced Renal Fibrosis: Targeting the PKM2-HIF-1α Pathway.

Renal fibrosis is a pathological characteristic of the endpoint of chronic kidney disease (CKD), which remains a major public health problem. None of the current therapies is effective in stopping kidney fibrosis progression. In light of our novel detection of a potential antifibrosis of microcystins (MCs), we investigate the renoprotection effect of MCs with UUO-induced renal fibrosis. The treatment of MCs was initiated in model animals in advance of UUO operation. After determining that the antifibrotic effect of MCs was independent of its toxicity, our study focused on the renoprotection of microcystin-RR (MC-RR), a lower toxic congener of MCs, in UUO mice and the cell models in vitro. The co-immunoprecipitation assay and recombination plasmid transfection were used in the investigation of the mechanism of antifibrosis of MC-RR. The data show that MC-RR substantially exerts an effect on renoprotection with suppression of the expression of TGF-ß1/Smad signaling molecules and a blockage in epithelial dedifferentiation and myofibroblast activation in UUO model animals. MC-RR shows a binding directly to pyruvate kinase M2 (PKM2), downregulates PKM2-HIF-1α signaling, restores the inhibited expression of MMP-7 and MMP-13, and reduces the upregulated expression of MMP-9 in UUO renal tissues. The current study demonstrates a novel effect of MC-RR on renoprotection in kidney damage, which could be conducted in therapeutics for chronic kidney disease.

Targeted and Untargeted Metabolomics Profiling of Wheat Reveals Amino Acids Increase Resistance to Fusarium Head Blight.

Fusarium head blight (FHB), a notorious plant disease caused by Fusarium graminearum (F. graminearum), is severely harmful to wheat production, resulting in a decline in grain quality and yield. In order to develop novel control strategies, metabolomics has been increasingly used to characterize more comprehensive profiles of the mechanisms of underlying plant-pathogen interactions. In this research, untargeted and targeted metabolomics were used to analyze the metabolite differences between two wheat varieties, the resistant genotype Sumai 3 and the susceptible genotype Shannong 20, after F. graminearum inoculation. The untargeted metabolomics results showed that differential amino acid metabolic pathways existed in Sumai 3 and Shannong 20 after F. graminearum infection. Additionally, some of the amino acid contents changed greatly in different cultivars when infected with F. graminearum. Exogenous application of amino acids and F. graminearum inoculation assay showed that proline (Pro) and alanine (Ala) increased wheat resistance to FHB, while cysteine (Cys) aggravated the susceptibility. This study provides an initial insight into the metabolite differences of two wheat cultivars under the stress of F. graminearum. Moreover, the method of optimization metabolite extraction presents an effective and feasible strategy to explore the understanding of the mechanisms involved in the FHB resistance.

Effects of supplemental irrigation at the jointing stage on population dynamics, grain yield, and water-use efficiency of two different spike-type wheat cultivars.

To solve the problems of yield reduction and low water-use efficiency (WUE) of winter wheat (Triticum aestivum L.) caused by winter and spring drought, a 2-year field experiment (2017-2019) was performed under movable shelter conditions with the large- and multispike cultivars Shannong 23 and 29, respectively, to explore the optimal supplemental irrigation regime. Three wetting layers were used for irrigation at the jointing stage: 0-10 cm (T2), 0-20 cm (T3) and 0-30 cm (T4). No irrigation at the jointing stage (T1) served as the control. Within a given cultivar, the soil water content in the 0-80 cm soil layers increased after irrigation, and the rate of tiller mortality decreased with increasing depth of the wetting layer used for irrigation at jointing. No significant differences were found between the T3 and T4 treatments in the photosynthetic rate (Pn) of the apical leaf of the main stem (O), the first primary tiller (I) and the fourth tiller (IV) after jointing. However, compared with the T3 treatment, the T4 treatment had a significantly higher transpiration rate (Tr) and lower instantaneous water-use efficiency (WUEleaf) of the apical leaf of the O and tillers I and IV. This eventually led to a decreasing WUE, although there was no significant change in the spike number or grain yield. These results indicated that moderate irrigation at jointing can effectively reduce the tiller mortality, improve the leaf Pn of the tillers, and increase the spike number and grain yield. However, excessive irrigation can significantly increase the leaf Tr of the tillers, lead to inefficient water consumption and significantly reduce the WUEleaf of the tillers and the WUE. Irrigation at the jointing stage brought the soil water content in the 0-20 cm profile to 100% of field capacity, making it the most suitable supplemental irrigation regime for both the large- and multispike cultivars in the North China Plain.

Optimization of Ultrasonic-Assisted Simultaneous Extraction of Three Active Compounds from the Fruits of Forsythia suspensa and Comparison with Conventional Extraction Methods.

An efficient ultrasonic-assisted extraction (UAE) method was developed for simultaneous extraction of three active compounds, forsythiaside A (FSA), phillyrin (PHI) and rutin (RT), from the fruits of Forsythia suspensa. The effects of various factors including a binary mixed solvent of methanol/water and ethanol/water, the pH of the solvent, particle size, temperature, solvent to material ratio, ultrasonic input power and extraction time on UAE were investigated in detail. The mass transfer mechanism of UAE using different mixed solvents was further explained by comparison with the maceration extraction method. The response surface methodology was used to optimize the experimental variables including ethanol concentration, solvent to material ratio and extraction time. The optimized conditions for the simultaneous extraction of RT, FSA and PHI were: particle size 60⁻80 mesh, temperature 30 °C, ultrasonic power 200 W, ethanol concentration 50%, solvent to material ratio 32 mL/g and extraction time 37 min. Compared to conventional extraction methods, UAE provided the highest extraction efficiency and offered many advantages including the reduction of solvent, temperature and time for extraction.

Development and validation of a sensitive UPLC-MS/MS instrumentation and alkaline nitrobenzene oxidation method for the determination of lignin monomers in wheat straw.

A method to determine the lignin monomers (p-hydroxybenzaldehyde, vanillin and syringaldehyde) in plant cell wall of wheat internode was developed and validated using a high-throughput nitrobenzene oxidation step and ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for quantification. UPLC analyses were carried out using an reversed phase C18 column (ACQUITY UPLC BEH, 1.7µm, 2.1×100mm) and gradient elution with water and acetonitrile. This method was completely validated in terms of analyzing speed, linearity, sensitivity, limits of detection (LODs) and limits of quantification (LOQs).The three lignin monomers were successfully separated within 6min and only 2min were required to regain its equilibrium. The method linearity with regression coefficients values (R2) greater than 0.997. Additionally, LODs ranged from 0.21 to 0.89µgL-1 and LOQs ranged from 0.69 to 2.95µgL-1. The applicability of this analytical approach for determining the three lignin monomers was confirmed by the successful analysis of real samples of wheat stem internodes. The nitrobenzene oxidation method was used for the analysis of lignin monomers. We have optimized the treatment temperature (170°C, 1h) and realized the high-throughput using the microwave digestion instrument. Recovery of this extraction method ranged from 68.4% to 77.7%. The analysis result showed that the guaiacyl unit (G) was the major component of lignin and there was a higher content of the syringyl unit (S) than that of the hydroxybenzyl unit (H).

Preparative separation of five flavones from flowers of Polygonum cuspidatum by high-speed countercurrent chromatography.

A preparative high-speed countercurrent chromatography method was successfully used for the isolation of five minor flavones from Polygonum cuspidatum flowers. Among them, three compounds were obtained from P. cuspidatum for the first time. A twin two-phase solvent system composed of n-hexane/ethyl acetate/ethanol/water (1:6:3:6, v/v/v/v) and petroleum ether/ethyl acetate/methanol/water (2:4:3:3, v/v/v/v) was developed. Compounds were obtained from the fraction B and fraction C prepurified by silica gel column chromatography. Five minor compositions, 6.8 mg of hesperidin, 11.2 mg of phloridzin, 4.9 mg of luteolin, 5.3 mg of hyperin, and 3.7 mg of luteoloside were obtained from 140 mg of the fraction B and 110 mg of fraction C with a purity of 95.3, 96.4, 98.0, 96.8, and 95.3%, respectively, as determined by high-performance liquid chromatography. The structures of these compounds were identified by (1) H and (13) C NMR spectroscopy.

Simultaneous determination of flavonoids in different parts of Citrus reticulata 'Chachi' fruit by high performance liquid chromatography-photodiode array detection.

Flavonoids are important polyphenolic secondary metabolites in plant. Citrus reticulata 'Chachi' fruit are rich in flavonoids and are being used as functional antioxidant ingredients for the treatment of atherosclerosis and cancer, etc. A high performance liquid chromatography-photodiode array detection system was used to analyze five flavonoids, namely, naringin, hesperidin, didymin, tangeretin and nobiletin, in different parts of C. reticulata 'Chachi' fruit. The chromatographic analysis was performed on a C(18) column with a gradient elution of acetonitrile and water at a flow rate of 1.0 mL/min. Detection was carried out using a photodiode array detector at 280 nm. The calibration curves for the determination of all analytes showed good linearity over the investigated ranges (R2 > 0.9995). Precision and reproducibility were evaluated by six replicated analyses, and the R.S.D. values were less than 0.9% and 2.7%. The recoveries were between 98.37 and 103.89%. This method is promising to improve the quality control of different parts of C. reticulata 'Chachi' fruit.

[CH4 absorption and its affecting factors in a wheat field with conservation tillage].

In order to understand the relationships between CH4 fluxes and its affecting factors in a wheat field with conservation tillage, the CH4 fluxes in two wheat fields, one with conservation tillage and the another with conventional tillage, were measured in situ by static chamber-GC method, with soil temperature and soil moisture and inorganic nitrogen contents determined at the same time. The results showed that these two fields had an obvious and similar seasonal variation pattern of CH4 fluxes, but the average and seasonal CH4 absorption fluxes differed significantly. In the growth period of wheat, the fields were the sink of CH4, and the CH4 absorption fluxes was in the order of conventional tillage with no straw returning (CN) > conventional tillage with straw returning (CS) > subsoiling with straw returning (PS) > harrowing with straw returning (HS) > rotary tillage with straw returning (RS) > no tillage with straw covered (NS). Comparing with conventional tillage, conservation tillage reduced the CH4 absorption fluxes. In conservation tillage, the CH4 absorption fluxes was positively correlated with soil temperature but negatively correlated with soil moisture content; while in conventional tillage, the CH4 absorption fluxes had no significant correlations with the two factors. In all treatments, there was a significant negative correlation between CH4 absorption fluxes and soil NH4+ -N content.