Amentoflavone-loaded nanoparticles enhanced chemotherapy efficacy by inhibition of AKR1B10.

Therapeutic nanoparticles can be combined with different anticancer drugs to achieve a synergistic therapy and avoid the limitations of traditional medicine and thus have clinical prospects for cancer. Herein, an effective nanoplatform was developed for self-assembling AMF@DOX-Fe3+-PEG nanoparticles (ADPF NPs) via the coordination of ferric ions (Fe3+), amentoflavone (AMF), doxorubicin (DOX), and PEG-polyphenol. The ADPF NPs possessed high drug loading efficiency, good stability and dispersion in water, prolonged blood circulation, and pH-dependent release, which leading to targeted drug transport and enhanced drug accumulation in the tumor. The AMF from the ADPF NPs could inhibit the expression of the Aldo-keto reductase family 1B10 (AKR1B10) and nuclear factor-kappa B p65 (NF-κB p65), which reduced the cardiotoxicity induced by DOX and enhanced the chemotherapy efficacy. This study established a new strategy of combining drug therapy with a nanoplatform. This new strategy has a wide application prospect in clinical tumor therapy.

Insights into acylation mechanisms: co-expression of serine carboxypeptidase-like acyltransferases and their non-catalytic companion paralogs.

Serine carboxypeptidase-like acyltransferases (SCPL-ATs) play a vital role in the diversification of plant metabolites. Galloylated flavan-3-ols highly accumulate in tea (Camellia sinensis), grape (Vitis vinifera), and persimmon (Diospyros kaki). To date, the biosynthetic mechanism of these compounds remains unknown. Herein, we report that two SCPL-AT paralogs are involved in galloylation of flavan-3-ols: CsSCPL4, which contains the conserved catalytic triad S-D-H, and CsSCPL5, which has the alternative triad T-D-Y. Integrated data from transgenic plants, recombinant enzymes, and gene mutations showed that CsSCPL4 is a catalytic acyltransferase, while CsSCPL5 is a non-catalytic companion paralog (NCCP). Co-expression of CsSCPL4 and CsSCPL5 is likely responsible for the galloylation. Furthermore, pull-down and co-immunoprecipitation assays showed that CsSCPL4 and CsSCPL5 interact, increasing protein stability and promoting post-translational processing. Moreover, phylogenetic analyses revealed that their homologs co-exist in galloylated flavan-3-ol- or hydrolyzable tannin-rich plant species. Enzymatic assays further revealed the necessity of co-expression of those homologs for acyltransferase activity. Evolution analysis revealed that the mutations of the CsSCPL5 catalytic residues may have taken place about 10 million years ago. These findings show that the co-expression of SCPL-ATs and their NCCPs contributes to the acylation of flavan-3-ols in the plant kingdom.

Polyphenol-Based Paclitaxel Prodrug Self-Assembled Nanoplatform for Tumor Synergistic Therapy.

With the development of nanomedicine, studies focus on self-assembled nanoplatforms to reduce the toxicity of paclitaxel (PTX), promote the immune function at low-toxicity PTX, and achieve tumor synergistic therapy. Herein, a new nanoplatform was prepared with self-assembled 5-hydroxydopamine (DA)-PTX@tannic acid (TA)-Fe3+ nanoparticles (TDPP NPs) by consolidation of targeted DA-PTX and TA with the assistance of coordination between polyphenols and Fe3+. The polyphenol-based TDPP NPs can reduce the toxicity of PTX and thereby realize the in vitro and in vivo synergistic effect against tumors. The low-toxicity TDPP NPs can enhance the expression of CD40 immune protein. Moreover, the TDPP NPs possessed a small size (52.2±4 nm), high drug loading efficiency (95%), and stable pharmacokinetics, ensuring high tumor accumulation of TDPP NPs by enhanced permeability and retention effect. Our work sheds new light on the nanoformulation of PTX with low toxicity and synergistic therapy effect, which may find clinical applications in the future.

Functional Analyses of Flavonol Synthase Genes From Camellia sinensis Reveal Their Roles in Anther Development.

Flavonoids, including flavonol derivatives, are the main astringent compounds of tea and are beneficial to human health. Many researches have been conducted to comprehensively identify and characterize the phenolic compounds in the tea plant. However, the biological function of tea flavonoids is not yet understood, especially those accumulated in floral organs. In this study, the metabolic characteristics of phenolic compounds in different developmental stages of flower buds and various parts of the tea flower were investigated by using metabolomic and transcriptomic analyses. Targeted metabolomic analysis revealed varying accumulation patterns of different phenolic polyphenol compounds during flowering; moreover, the content of flavonol compounds gradually increased as the flowers opened. Petals and stamens were the main sites of flavone and flavonol accumulation. Compared with those of fertile flowers, the content of certain flavonols, such as kaempferol derivatives, in anthers of hybrid sterile flowers was significantly low. Transcriptomic analysis revealed different expression patterns of genes in the same gene family in tea flowers. The CsFLSb gene was significantly increased during flowering and was highly expressed in anthers. Compared with fertile flowers, CsFLSb was significantly downregulated in sterile flowers. Further functional verification of the three CsFLS genes indicated that CsFLSb caused an increase in flavonol content in transgenic tobacco flowers and that CsFLSa acted in leaves. Taken together, this study highlighted the metabolic properties of phenolic compounds in tea flowers and determined how the three CsFLS genes have different functions in the vegetative and reproductive organs of tea plants. Furthermore, CsFLSb could regulated flavonol biosynthesis in tea flowers, thus influencing fertility. This research is of great significance for balancing the reproductive growth and vegetative growth of tea plants.

Myricetin-Based Self-Assembled Nanoparticles for Tumor Synergistic Therapy by Antioxidation Pathway.

Nanoplatforms are nano-scale systems that can transport different small molecular anticancer drugs or chemosensitization motif to accumulate in tumor cells without obvious side-effect in normal cells and achieve a synergistic therapy. In this paper the new self-assembled nanoparticles (NPs) merging doxorubicin (DOX) and myricetin (MYR) with ferric ions (Fe3+) and polyphenol was employed for forming the DOX@MYR-Fe3+ NP (FDMP NP). The FDMP NPs could reduce the DOX-induced toxicity in blood; and they could not cause damage to the heart and kidney tissues by the reasons that the MYR could enhance the anti-oxidation capability in normal cells, which resulted in preventing ROS-induced damage. Additionally, the FDMP NPs were characteristic of small size (37.70 ± 6.30 nm), high DOX loading efficiency (46.67 ± 1.58%), pH-controlled release and excellent stable pharmacokinetics, that inducing drug release and enhancing drug accumulation in the tumor. Moreover, the FDMP NPs could inhibit the expression of the hypoxia-inducible factor-1 α(HIF-1α) and the key angiogenesis mediator vascular endothelial growth factor (VEGF) both in vitro and in vivo, which succeed in preventing the generation of new blood vessel networks; that is the mechanism of the synergistic effect against tumors induced by FDMP NPs.

First Report of Cercospora nicotianae Causing Frog Eye Spot in Cigar Tobacco in Hainan, China.

Cigar tobacco (Nicotiana tabacum L.), sun air-cured tobacco, originally from South America, with a main use to rolling cigar wrapper that is different from flue-cured tobacco. In April, 2018, diseased leaves were observed in cigar tobacco in some fields in Danzhou city (109.58°E, 19.53°N) and Wuzhishan city (109.52°E, 18.78°N), Hainan. 20 to 40% of plants were infected (total 8 ha), thereby affecting local leaf production. The symptoms appeared as small, circular or irregular, sunken, brown patches developing into white centers and obvious dark brown margins with necrotic spots of 0.2-0.8 cm in most middle and lower leaves at mature stage. To determine the causal agent, ten leaves from five cigar tobacco plants (cv. Nuowei 2) collected from Danzhou were used for pathogen isolation (Fig. 1). Sections of infected leaf tissues were surface-sterilized by 5% NaClO for 3 min, 70% ethanol for 40 sec, rinsed in sterilized distilled water (SDW) and then placed onto potato dextrose agar (PDA) plates, under aseptic conditions and incubated at 28°C. After 7 days, predominant and consistent colonies that were nearly circular, smooth edges, generally hard, leathery and wrinkled surface, dense aerial hyphae, producing red pigment, were obtained and purified by picking hyphal tips to PDA at 28℃ (Fig. 2). One culture, HN4-1-7 from Hainan were deposited in Chinese General Microbial Cultural Center (CGMCC, NO. 3.19604). Frogeye lesions can be coved by tiny black dots on two sides and the fruiting bodies was amphigenous. Conidiophores were bluish yellow brown and gradually lighten at tips, 0-4 knee points, apical or subapical section, 0-14 septa, measured 45.1-506.4×2.3-11.7 µm in size. Conidia were needle-shaped to clavate, colorless, erect or curved, measured 37.2-169.6×1.9-5.5µm (Fig. 2). Further comparisons were completed with CGMCC 3.19604 by PCR and BLAST sequence analyses of the patial ITS rDNA region (GenBank accession nos. MK752900), TEF gene (GenBank accession nos. MK881748), ACT gene (GenBank accession nos. MK881749), CAL gene (GenBank accession nos. MT127561), and HIS gene (GenBank accession nos. MT185579) as described by Groenewald et al (2012). The results showed high identity of all the five sequences to the Cercospora nicotianae isolates, DQ835073, DQ835099, DQ835119, DQ835146, DQ835173. Based on the microscopic observation and molecular characteristics, isolate CGMCC 3.19604 were identified as C. nicotianae. The pathogenicity of CGMCC 3.19604 was evaluated in greenhouse experiments. Twenty sixty-day old cigar tobacco leaves (cv. H211) and flue cured tobacco leaves (Honghuadajinyuan) were sprayed with hyphae suspensions of CGMCC, NO. 3.19604 until runoff, respectively, and the experiment was repeated once. For controls, leaves of two cultivars were similarly wounded and inoculated with SDW. All plants were incubated under 90% humidity and 28°C with a 12 h photoperiod/day. After 9 days, the same diseased symptom (Fig.3) was observed on inoculated leaves of cigar tobacco were identical to the natural infected leaves respectively, but not on control leaves. C. nicotianae was re-isolated from lesions by cultural and morphological characteristics, fufilling Koch's postulates. All tests were repeated once. To the best of our knowledge, this is the first report of C. nicotianae causing frog eye spot in cigar tobacco in Hainan, China. As we all known, appearance integrity and uniformity are playing an important role in high quality of cigar-wrapper, but the incidence of frog eye spot can seriously affect appearance quality of cigar-wrapper and led to increase direct losses to local cigar tobacco production. In addition, symptom of frog eye spot is similar to brown spot disease caused by Alternaria alternata, often cause their symptoms confused and then delay prevention at the right time. Since the cigar tobacco is a major industry in Hainan, better understanding of its diseases is relevant in order to establish disease control strategies.

Targeted Prodrug-Based Self-Assembled Nanoparticles for Cancer Therapy.

BACKGROUND: Targeted prodrug has various applications as drug formulation for tumor therapy. Therefore, amphoteric small-molecule prodrug combined with nanoscale characteristics for the self-assembly of the nano-drug delivery system (DDS) is a highly interesting research topic. METHODS AND RESULTS: In this study, we developed a prodrug self-assembled nanoplatform, 2-glucosamine-fluorescein-5(6)-isothiocyanate-glutamic acid-paclitaxel (2DA-FITC-PTX NPs) by integration of targeted small molecule and nano-DDS with regular structure and perfect targeting ability. 2-glucosamine (DA) and paclitaxel were conjugated as the targeted ligand and anti-tumor chemotherapy drug by amino acid group. 2-DA molecular structure can enhance the targeting ability of prodrug-based 2DA-FITC-PTX NPs and prolong retention time, thereby reducing the toxicity of normal cell/tissue. The fluorescent dye FITC or near-infrared fluorescent dye ICG in prodrug-based DDS was attractive for in vivo optical imaging to study the behavior of 2DA-FITC-PTX NPs. In vitro and in vivo results proved that 2DA-FITC-PTX NPs exhibited excellent targeting ability, anticancer activity, and weak side effects. CONCLUSION: This work demonstrates a new combination of nanomaterials for chemotherapy and may promote prodrug-based DDS clinical applications in the future.

Effects of vitro sucrose on quality components of tea plants (Camellia sinensis) based on transcriptomic and metabolic analysis.

BACKGROUND: Tea plants [Camellia sinensis (L.) O. Kuntze] can produce one of the three most widely popular non-alcoholic beverages throughout the world. Polyphenols and volatiles are the main functional ingredients determining tea's quality and flavor; however, the biotic or abiotic factors affecting tea polyphenol biosynthesis are unclear. This paper focuses on the molecular mechanisms of sucrose on polyphenol biosynthesis and volatile composition variation in tea plants. RESULTS: Metabolic analysis showed that the total content of anthocyanins, catechins, and proanthocyanidins(PAs) increased with sucrose, and they accumulated most significantly after 14 days of treatment. Transcriptomic analysis revealed 8384 and 5571 differentially expressed genes in 2-day and 14-day sucrose-treated tea plants compared with control-treated plants. Most of the structural genes and transcription factors (TFs) involved in polyphenol biosynthesis were significantly up-regulated after 2d. Among these transcripts, the predicted genes encoding glutathione S-transferase (GST), ATP-binding cassette transporters (ABC transporters), and multidrug and toxic compound extrusion transporters (MATE transporters) appeared up regulated. Correspondingly, ultra-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-QQQ-MS/MS) analysis revealed that the content of non-galloylated catechins and oligomeric PAs decreased in the upper-stem and increased in the lower-stem significantly, especially catechin (C), epicatechin (EC), and their oligomeric PAs. This result suggests that the related flavonoids were transported downward in the stem by transporters. GC/MS data implied that four types of volatile compounds, namely terpene derivatives, aromatic derivatives, lipid derivatives, and others, were accumulated differently after in vitro sucrose treatment. CONCLUSIONS: Our data demonstrated that sucrose regulates polyphenol biosynthesis in Camellia sinensis by altering the expression of transcription factor genes and pathway genes. Additionally, sucrose promotes the transport of polyphenols and changes the aroma composition in tea plant.

Draft Genome Sequence of Novosphingobium sp. Strain HII-3, a Bacterium Capable of Degrading the Cembranoid α(ß)-2,7,11-Cembratriene-4,6-Diol to Farnesal.

Novosphingobium sp. HII-3, the first bacterium confirmed to degrade the cembranoid α(ß)-2,7,11-cembratriene-4,6-diol to farnesal, was isolated from cured tobacco leaf in Henan, China. Here, we report the annotated draft genome sequence of strain HII-3, which has an estimated size of 4.45 Mb and comprises 4,072 coding sequences.

Metabolic Characterization of the Anthocyanidin Reductase Pathway Involved in the Biosynthesis of Flavan-3-ols in Elite Shuchazao Tea (Camellia sinensis) Cultivar in the Field.

Anthocyanidin reductase (ANR) is a key enzyme in the ANR biosynthetic pathway of flavan-3-ols and proanthocyanidins (PAs) in plants. Herein, we report characterization of the ANR pathway of flavan-3-ols in Shuchazao tea (Camellia sinesis), which is an elite and widely grown cultivar in China and is rich in flavan-3-ols providing with high nutritional value to human health. In our study, metabolic profiling was preformed to identify two conjugates and four aglycones of flavan-3-ols: (-)-epigallocatechin-gallate [(-)-EGCG], (-)-epicatechin-gallate [(-)-ECG], (-)-epigallocatechin [(-)-EGC], (-)-epicatechin [(-)-EC], (+)-catechin [(+)-Ca], and (+)-gallocatechin [(+)-GC], of which (-)-EGCG, (-)-ECG, (-)-EGC, and (-)-EC accounted for 70-85% of total flavan-3-ols in different tissues. Crude ANR enzyme was extracted from young leaves. Enzymatic assays showed that crude ANR extracts catalyzed cyanidin and delphinidin to (-)-EC and (-)-Ca and (-)-EGC and (-)-GC, respectively, in which (-)-EC and (-)-EGC were major products. Moreover, two ANR cDNAs were cloned from leaves, namely CssANRa and CssANRb. His-Tag fused recombinant CssANRa and CssANRb converted cyanidin and delphinidin to (-)-EC and (-)-Ca and (-)-EGC and (-)-GC, respectively. In addition, (+)-EC was observed from the catalysis of recombinant CssANRa and CssANRb. Further overexpression of the two genes in tobacco led to the formation of PAs in flowers and the reduction of anthocyanins. Taken together, these data indicate that the majority of leaf flavan-3-ols in Shuchazao's leaves were produced from the ANR pathway.

Sulfated lentinan induced mitochondrial dysfunction leads to programmed cell death of tobacco BY-2 cells.

Sulphated lentinan (sLTN) is known to act as a resistance inducer by causing programmed cell death (PCD) in tobacco suspension cells. However, the underlying mechanism of this effect is largely unknown. Using tobacco BY-2 cell model, morphological and biochemical studies revealed that mitochondrial reactive oxygen species (ROS) production and mitochondrial dysfunction contribute to sLNT induced PCD. Cell viability, and HO/PI fluorescence imaging and TUNEL assays confirmed a typical cell death process caused by sLNT. Acetylsalicylic acid (an ROS scavenger), diphenylene iodonium (an inhibitor of NADPH oxidases) and protonophore carbonyl cyanide p-trifluoromethoxyphenyl hydrazone (a protonophore and an uncoupler of mitochondrial oxidative phosphorylation) inhibited sLNT-induced H2O2 generation and cell death, suggesting that ROS generation linked, at least partly, to a mitochondrial dysfunction and caspase-like activation. This conclusion was further confirmed by double-stained cells with the mitochondria-specific marker MitoTracker RedCMXRos and the ROS probe H2DCFDA. Moreover, the sLNT-induced PCD of BY-2 cells required cellular metabolism as up-regulation of the AOX family gene transcripts and induction of the SA biosynthesis, the TCA cycle, and miETC related genes were observed. It is concluded that mitochondria play an essential role in the signaling pathway of sLNT-induced ROS generation, which possibly provided new insight into the sLNT-mediated antiviral response, including PCD.

Functional Characterization of a New Tea (Camellia sinensis) Flavonoid Glycosyltransferase.

Tea (Camellia sinensis) is an important commercial crop, in which the high content of flavonoids provides health benefits. A flavonoid glycosyltransferase (CsUGT73A20), belonging to cluster IIIa, was isolated from tea plant. The recombinant CsUGT73A20 in Escherichia coli exhibited a broad substrate tolerance toward multiple flavonoids. Among them, kaempferol was the optimal substrate compared to quercetin, myricetin, naringenin, apigenin, and kaempferide. However, no product was detected when UDP-galactose was used as the sugar donor. The reaction assay indicated that rCsUGT73A20 performed multisite glycosidation toward flavonol compounds, mainly forming 3-O-glucoside and 7-O-glucoside in vitro. The biochemical characterization analysis of CsUGT73A20 showed more K7G product accumulated at pH 8.0, but K3G was the main product at pH 9.0. Kinetic analysis demonstrated that high pH repressed the glycosylation reaction at the 7-OH site in vitro. Besides, the content of five flavonol-glucosides was increased in CsUGT73A20-overexpressing tobaccos (Nicotiana tabacum).

Sleep Quality of Patients with Differentiated Thyroid Cancer.

OBJECTIVE: We aimed to measure prevalence of sleep disturbance in patients with differentiated thyroid cancer (DTC) by calculating Pittsburgh Sleep Quality Index (PSQI), and compare these data with patients with benign thyroid nodules or normal participants. METHODS: Three groups of patients participated in this cross-sectional study. In the first group, 162 patients with DTC received total thyroidectomy, and then 131I therapy. The second group consisted of 84 patients with benign thyroid nodules, who received partial thyroidectomy. The third group was 78 normal healthy control cases. PSQI was used to assess the sleep quality. Inter-group differences were analyzed by Kruskal-Wallis test or independent samples T test. χ2 test was also used to check prevalence differences of poor sleep quality among the groups. Differences of PSQI score and poor sleep quality prevalence before and after 131I therapy in the same group of DTC participants were analyzed by paired T test and Mcnemar's test. RESULTS: Higher PSQI score (7.59 ± 4.21) and higher rate of poor sleep quality (54.32%) were shown in DTC patients than in any other group. After 131I therapy, PSQI score and prevalence of poor sleep quality in DTC patients increased significantly to 8.78 ± 4.72 and 70.99%. Then DTC patients were divided into two subgroups based on their metastatic status. DTC patients with metastasis (87/162 cases, 53.70%) had significantly higher PSQI score (10.87 ± 5.18) and higher prevalence of poor sleep quality (79.31%). CONCLUSION: DTC patients suffer from sleep disturbance, 131I therapy and awareness of metastatic status could worsen sleep problem. Psychological fear of cancer, nuclear medicine therapy and metastasis could be one major underlying reason. Longitude and interventional studies are necessary for further investigations.

Inhibitory effects of sulfated lentinan with different degree of sulfation against tobacco mosaic virus (TMV) in tobacco seedlings.

The inhibitory effects of sulfated lentinan with different degrees of sulfation against tobacco mosaic virus (TMV) and the underlying mechanism were investigated. The results indicated that plants treated with increasing concentrations of sulfated lentinan, with increasing numbers of treatments and with increasing time after treatment had a decrease in the number of necrotic lesions, indicating a long-term protection against TMV that mimics vaccination. In addition, the levels of TMV-capsid protein (CP) transcripts decreased in distant leaves, indicating that sulfated lentinan induces systemic protection against TMV. The activities of the defense enzymes phenylalanine ammonia lyase (PAL) and lipoxygenase (LOX) and the amounts of several phenylpropanoid compounds (PPCs) were measured in control and treated plants without infection. A progressive increase in PAL activity was observed with increasing time after treatment, together with the accumulation of free and conjugated PPCs. In contrast, LOX activity remained unchanged. Interestingly, the increase in PAL activity showed a linear correlation with the decrease in necrotic lesions and the decrease in TMV-CP transcript level. Thus, sulfated lentinan induced systemic and long-term protection against TMV in tobacco plants that is determined, at least in part, by a sustained activation of PAL and the accumulation of PPCs with potential antiviral activity.

Numeric simulation of the upper airway structure and airflow dynamic characteristics after unilateral complete maxillary resection.

This study investigated upper airway aerodynamic characteristics of patients who underwent maxillectomy using three-dimensional reconstruction and computational fluid dynamics. The results revealed the generation of low-velocity vortices throughout the entire maxillary defect during respiration. The nasal structure on the nonsurgical side changed postsurgically, possibly due to the pressure gradient between the defective and healthy side. The bilateral disturbed airflow patterns are believed to be the cause of common symptoms. The numeric simulation technique could be used as a potential method to understand upper airway morphology changes and respiratory functions, thus guiding the fabrication of prostheses.

Development of a one-step immunocapture real-time RT-PCR assay for detection of tobacco mosaic virus in soil.

Tobacco mosaic virus (TMV) causes significant losses in many economically important crops. Contaminated soils may play roles as reservoirs and sources of transmission for TMV. In this study we report the development of an immunocapture real-time RT-PCR (IC-real-time RT-PCR) assay for direct detection of TMV in soils without RNA isolation. A series of TMV infected leaf sap dilutions of 1:101, 1:102, 1:103, 1:104, 1:105 and 1:106 (w/v, g/mL) were added to one gram of soil. The reactivity of DAS-ELISA and conventional RT-PCR was in the range of 1:102 and 1:103 dilution in TMV-infested soils, respectively. Meanwhile, the detection limit of IC-real-time RT-PCR sensitivity was up to 1:106 dilution. However, in plant sap infected by TMV, both IC-real-time RT-PCR and real-time RT-PCR were up to 1:106 dilution, DAS-ELISA could detect at least 1:103 dilution. IC-real-time RT-PCR method can use either plant sample extracts or cultivated soils, and show higher sensitivity than RT-PCR and DAS-ELISA for detection of TMV in soils. Therefore, the proposed IC-real-time RT-PCR assay provides an alternative for quick and very sensitive detection of TMV in soils, with the advantage of not requiring a concentration or RNA purification steps while still allowing detection of TMV for disease control.

Rapid detection of tobacco mosaic virus using the reverse transcription loop-mediated isothermal amplification method.

Tobacco mosaic virus (TMV) can cause a severe disease that is capable of greatly reducing tobacco quality and yield. In this study, a one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for detection of TMV. The concentration of Mg(2+), reaction temperature and reaction time of the RT-LAMP were optimized to 5 mM, 65°C, and 60 min, respectively. The detection limit of the method was 100 times higher than that of RT-PCR. Visual inspection of RT-LAMP amplification demonstrated that positive and negative reactions exhibit distinctly different colours in daylight. Our results demonstrate that the method is stable, sensitive and specific.