Novel Aminocoumarin Derivatives against Phytopathogenic Fungi: Design, Synthesis and Structure-Activity Relationships.

Phytopathogenic fungi is the most devastating reason for the decrease of the agricultural production and food safety. To develop new fungicidal agents for resistance concerning, a novel series of aminocoumarin derivatives were synthesized and their fungicidal activity were investigated both in vitro and in vivo. Transmission electron microscope (TEM), scanning electron microscope (SEM), RNA-Seq, 3D-QSAR and molecular docking were applied to reveal the underlying anti-fungal mechanisms. Most of the compounds exhibited significant fungicidal activity. Notably, compound 10c had a more extensive fungicidal effect than positive control. TEM indicated that compound 10c could cause abnormal morphology of cell walls, vacuoles and release of cellular contents. Transcriptional analysis data indicated that 895 and 653 out of 1548 differential expressed genes (DEGs) were up-regulated and down-regulated respectively. The Go and KEGG enrichment indicated that the coumarin derivatives could induce significant changes of succinate dehydrogenase (SDH), Acetyl-coenzyme A synthetase (ACCA) and pyruvate dehydrogenase (PDH) genes, which contributed to the disorders of glucolipid metabolism and the dysfunction of mitochondrial. The results demonstrated that aminocoumarins with schiff-base as core moieties could be the promising lead compounds for the discovery of novel fungicides.

Trimethylamine N-Oxide (TMAO) Inducing Endothelial Injury: UPLC-MS/MS-Based Quantification and the Activation of Cathepsin B-Mediated NLRP3 Inflammasome.

TMAO is a new risk biomarker for cardiovascular disease. With trimethylammonium as its main chemical skeleton, TMAO is structurally similar to many endogenous metabolites, such as acetylcholine, carnitine, phosphorylcholine, etc. The mechanism of TMAO on the pathological process of CVD is still unclear. In this study, the quantitative analysis of plasma TMAO is conducted, and the contribution of Cathepsin B and NLRP3 inflammasome during the process of TMAO-induced endothelial injury was proposed and investigated at animal and cellular levels. Immunofluorescence assay was applied to represent the protein expression of Cathepsin B and NLRP3 inflammasome located at endothelial cells. The results showed that TMAO could disrupt endothelial cells permeability to induce endothelial injury, meanwhile, TMAO could increase NLRP3 inflammasome activation and promote the activity and expression of Cathepsin B in vitro and in vivo, whereas inhibition of NLRP3 inflammasome activation by MCC950 could protect the endothelial cells from TMAO associated endothelial injury via Cathepsin B. The study reveals that TMAO can cause endothelial injury via Cathepsin B-dependent NLRP3 inflammasome, and inhibition of Cathepsin B and NLRP3 inflammasome can reduce the TMAO-induced damage. The results provide new insight into the role of TMAO in CVD, which can be a potential therapeutic target for disease treatment and drug design.

Iron metabolism disorder regulated by BMP signaling in hypoxic pulmonary hypertension.

BACKGROUNDS AND AIMS: Unexplained iron deficiency is associated with poorer survival in patients with pulmonary hypertension (PH). Bone morphogenetic protein (BMP) signaling and BMP protein type II receptor (BMPR2) expression are important in the pathogenesis of PH. BMP6 in hepatocytes is a central transcriptional regulator of the iron hormone hepcidin that controls systemic iron balance. This study aimed to investigate the effects of BMP signaling on iron metabolism and its implication in hypoxia-induced PH. METHODS AND RESULTS: PH was induced in Sprague-Dawley Rats under hypoxia for 4 weeks. Compared with the control group, right ventricular systolic pressure and right ventricle hypertrophy index were both markedly increased, and serum iron level was significantly decreased with iron metabolic disorder in the hypoxia group. In cultured human pulmonary artery endothelial cells (HPAECs), hypoxia increased oxidative stress and apoptosis, which were reversed by supplementation with Fe agent. Meanwhile, iron chelator deferoxamine triggered oxidative stress and apoptosis in HPAECs, and treatment with antioxidant alleviated iron-deficiency-induced apoptosis by reducing reactive oxygen species production. Expression of hepcidin, BMP6 and hypoxia-inducible factor (HIF)-1α were significantly upregulated, while expression of BMPR2 was downregulated in hepatocytes in the hypoxia group, both in vivo and in vitro. Expression of hepcidin and HIF-1α were significantly increased by BMP6, while pretreatment with siRNA-BMPR2 augmented the enhanced expression of hepcidin and HIF-1α induced by BMP6. CONCLUSIONS: Iron deficiency promoted oxidative stress and apoptosis in HPAECs in hypoxia-induced PH, and enhanced expression of hepcidin regulated by BMP6/BMPR2 signaling may contribute to iron metabolic disorder.

Xanthanolides in Xanthium L.: Structures, Synthesis and Bioactivity.

Xanthanolides were particularly characteristic of the genus Xanthium, which exhibited broad biological effects and have drawn much attention in pharmacological application. The review surveyed the structures and bioactivities of the xanthanolides in the genus Xanthium, and summarized the synthesis tactics of xanthanolides. The results indicated that over 30 naturally occurring xanthanolides have been isolated from the genus Xanthium in monomeric, dimeric and trimeric forms. The bioassay-guided fractionation studies suggested that the effective fractions on antitumor activities were mostly from weak polar solvents, and xanthatin (1) was the most effective and well-studied xanthanolide. The varieties of structures and structure-activity relationships of the xanthanolides had provided the promising skeleton for the further study. The review aimed at providing guidance for the efficient preparation and the potential prospects of the xanthanolides in the medicinal industry.

Hypoxia-elicited cardiac microvascular endothelial cell-derived exosomal miR-210-3p alleviate hypoxia/reoxygenation-induced myocardial cell injury through inhibiting transferrin receptor 1-mediated ferroptosis.

OBJECTIVE: Ferroptosis is a novel mode of non-apoptotic cell death induced by build-up of toxic lipid peroxides (lipid-ROS) in an iron dependent manner, which is a key event in ischemia/reperfusion (I/R)-induced cardiomyocytes damages. Studies indicated that ischemic preconditioning with cardiac microvascular endothelial cells (CMECs) protected against I/R-induced cardiomyocytes damages. However, the role of hypoxia-conditioned CMECs-derived Exo (H-exo) in I/R cardiomyocytes damages remains largely unclear. Therefore, the objective of this study was to explore the role and underlying mechanisms of H-exo in hypoxia/reoxygenation(H/R)-induced H9C2 cells damages. METHODS: The rat CMECs were subjected to hypoxia or normoxia culture and Exo was subsequently collected and identified. H-exo or normoxia-conditioned CMECs-derived Exo (N-exo) were administered to H9C2 cells with H/R. To evaluate the therapeutic effect of H-exo and H-exo on H/R-induced H9C2 cells damages, cell proliferation was detected by CCK-8 assay and Edu staining, and ferroptosis process were evaluated by iron ion concentration, lipid reactive oxygen species (ROS) level, malondialdehyde (MDA) level, glutathione peroxidase (GSH-Px) level, and the protein expression of ferroptosis markers. Mechanically, we utilized the RT-qPCR to identify the expression of candidate miR-210-3p in N-exo and H-exo. Bioinformatics combined with dual luciferase reporter assay disclosed the downstream molecular mechanism of miR-210-3p. RESULTS: The results indicated that both H-exo and N-exo significantly facilitated cell proliferation, increased GSH-Px levels and ferroptosis marker (GPX4) protein levels, and reduced iron ion concentration, lipid ROS level, MDA levels and ferroptosis markers (ACSL4 and PTGS2) protein levels in H/R-treated H9C2 cells. More importantly, the therapeutic effect of H-exo was significantly better than that of N-exo. Mechanistically, the results of RT-qPCR revealed significant enrichment of miR-210-3p in H-exo compared with N-exo. The miR-210-3p delivered by H-exo inhibited TFR expression by directly interacting with TFR mRNA, resulting in the promotion of cell proliferation and the attenuation of cell ferroptosis in H/R-treated H9C2 cells. CONCLUSION: All these data demonstrated that H-exo derived miR-210-3p facilitated the proliferation of myocardial cells in H/R-treated H9C2 cells by suppressing TFR-mediated ferroptosis, which provided new methods to treat H/R-induced myocardial injury.

UHPLC-QTOF-MS/MS based characterization of anti-tumor constituents in Ceratocarpus arenarius L. and identification of EGFR-TK inhibitors by virtual screening.

The constituents of Ceratocarpus arenarius L., as a traditional anticancer medicine of Kazakh, were firstly profiled with UHPLC-QTOF-MS/MS. The potential compounds against EGFR-TK were virtually screened. As a result, forty-four compounds were analyzed, including 18 flavonoids, 8 steroids, 4 phenolic acids, 9 fatty acids, 1 coumarin and 4 other compounds. Among them, 9 flavonoids, N-trans-Feruloyltyramine (5), stigmasterol (11) and carthamone (38) were recognized as potential key anti-tumor constituents of C. arenarius through docking to active site of EGFR-TK. It indicated that the compounds formed moderate to strong interactions with EGFR-TK contributing to the antitumor activity through a synergetic actions. Besides, the anticancer effects of C. arenarius was verified with in-vitro anti-tumor activity investigation against A549. Our results firstly reveals the active constituents basis of C. arenarius against cancer and provides novel insights into the further application of effective constituents and mechanism of C. arenarius.

Dual-Responsive Alginate Hydrogel Constructed by Sulfhdryl Dendrimer as an Intelligent System for Drug Delivery.

Intelligent stimulus-triggered release and high drug-loading capacity are crucial requirements for drug delivery systems in cancer treatment. Based on the excessive intracellular GSH expression and pH conditions in tumor cells, a novel glutathione (GSH) and pH dual-responsive hydrogel was designed and synthesized by conjugates of glutamic acid-cysteine dendrimer with alginate (Glu-Cys-SA) through click reaction, and then cross-linked with polyethylene glycol (PEG) through hydrogen bonds to form a 3D-net structure. The hydrogel, self-assembled by the inner disulfide bonds of the dendrimer, is designed to respond to the GSH heterogeneity in tumors, with a remarkably high drug loading capacity. The Dox-loaded Glu-Cys-SA hydrogel showed controlled drug release behavior, significantly with a release rate of over 76% in response to GSH. The cytotoxicity investigation indicated that the prepared DOX-loaded hydrogel exhibited comparable anti-tumor activity against HepG-2 cells with positive control. These biocompatible hydrogels are expected to be well-designed GSH and pH dual-sensitive conjugates or polymers for efficient anticancer drug delivery.

X anthium Orientale subsp. Italicum (Moretti) Greuter: bioassay-guided isolation and its chemical basis of antitumor cytotoxicity.

Inspired by the allelopathetic effects of Xanthium orientale subsp. italicum (Moretti) Greuter, bioassay-guided isolation was employed to identify its antitumor constituents and clarify the chemical basis of its multitarget activity. Among four fractions of X.orientale extraction, TCM-fr and PE-fr were discovered to exhibit significant cytotoxicity aganist HepG two and A549 cells, which were further isolated by chromatographic methods to yield 16 compounds, including six active ones: xanthatin (1), xanthinosin (2), lupeol (6), oleanolic acid (9), betulinic acid (10) and emodin (12) with IC50 of 10 ∼ 120µM. The systematically study of antitumor constituents has firstly provided a chemical basis for the multitarget and synergistic anticancer activity of the genus Xanthium. The method presented could be utilized to guide the exploitation and promising utilization of X. orientale on cancer therapy.

Structured oral examination as an effective assessment tool in lab-based physiology learning sessions.

Traditional oral examination (TOE) is criticized for the shortage of objectivity, standardization, and reliability. These perceived limitations can be mitigated by the introduction of structured oral examination (SOE). There is little evidence of the implementation of SOE in physiology laboratory courses. The purpose of this study was to investigate the effect of SOE in laboratory-based learning sessions. Second-year medical students (n = 114) attended a 16-wk physiology laboratory course. They were initially assessed by TOE in the middle of the academic term. The students' perspectives on this assessment were measured by a modified three-point Likert-type scale questionnaire. Following this, faculty members prepared topics for SOE; nine topics were included from each laboratory course. The correct answers and scoring criteria were discussed among the faculty before the SOE event. One week after the last laboratory course, SOE was carried out for each student. As with the TOE process, student feedback was collected via a modified three-point Likert-type scale questionnaire. The mean laboratory homework score from the first four and last four laboratory courses was also calculated. Paper exams were also conducted after TOE and SOE. The results show that SOE is more acceptable to students than TOE. Significant differences (P < 0.05) were observed in terms of uniformity of questions asked, syllabus coverage, and anxiety levels. In addition, SOE improved students' performance in the laboratory course explored here. We contend that SOE shows promise as an effective assessment tool in laboratory-based physiology learning sessions.

Ellagic acid promotes browning of white adipose tissues in high-fat diet-induced obesity in rats through suppressing white adipocyte maintaining genes.

Promoting brown adipose tissue (BAT) formation and function reduces obesity. Ellagic Acid (EA), located abundantly in plant extracts and fruits, has been shown to modulate formation and differentiation of adipocytes, although its role in the process of browning of white adipose tissue (WAT) has not been elucidated. In this study, fifty-six five-week old SD rats were randomly assigned to receive normal diet (ND, 10% lipids) or high-fat diet (HFD, 60% lipid) with or without various dosages of EA for 24 weeks. Our results showed that high fat diet intake triggered overweight, glucose intolerance and white adipocyte hypertrophy, the effects of which were mitigated by EA treatment. Meanwhile, EA supplementation reduced serum resistin levels, improved hepatic steatosis and serum lipid profile in DIO (high fat diet induced obesity) rats. Moreover, EA supplementation significantly decreased mRNA expression of Zfp423 and Aldh1a1, the key determinants of WAT plasticity. EA also increased mRNA expression of brown adipocyte markers including UCP1, PRDM16, Cidea, PGC1α, Ppar-α; beige markers including CD137and TMEM26; mitochondrial biogenesis markers including TFAM in inguinal WAT (iWAT) when compared to their counterparts. EA treatment significantly improved mitochondrial function, as measured by citrate synthase activity. More importantly, EA markedly elevated the expression of UCP1 in iWAT, which is a specific protein of brown adipocyte. In conclusion, our results provided evidence that EA improved obesity-induced dyslipidemia and hepatic steatosis in DIO rats via browning of iWAT through suppressing white adipocyte maintaining genes and promoting expression of key thermogenic genes. These findings suggest that EA could be a promising therapeutic avenue to treat metabolic diseases.

Promising Fungicides from Allelochemicals: Synthesis of Umbelliferone Derivatives and Their Structure⁻Activity Relationships.

Umbelliferone was discovered to be an important allelochemical in our previous study, but the contribution of its activity and structure has not yet been revealed. In this study, a series of analogues were synthesized to determine the skeleton of umbelliferone and examine its fungicidal activity. Furthermore, targeted modifications were conducted with three plant parasitic fungi to examine the lead compounds. Among those tested, compounds 2f and 10 were found to show excellent antifungal activity with an inhibitory rate over 80% at 100 ug/mL. The study proves that umbelliferone can be a promising skeleton for fungicides discovery. In addition, the primary structure⁻activity relationship provides a good guidance for the discovery of novel fungicides based on natural products in the future.

Endoplasmic Reticulum Stress Related Molecular Mechanisms in Nonalcoholic Fatty Liver Disease (NAFLD).

Non-alcoholic fatty liver disease (NAFLD) is a common public health issue and is considered a main drive for liver diseases. However, the basic mechanisms that trigger the development of NAFLD still remain somewhat elusive. Endoplasmic reticulum (ER) stress facilitates the unfolded protein response (UPR) and contributes to the etiology of steatosis, nonalcoholic steatohepatitis and ultimately hepatocarcinoma. Although ER stress may lead to a cascade of compensatory responses that help to restore ER homeostasis, cell survival and adaptation, prolonged ER stress is known to impose detrimental pathological outcome, involving insulin resistance, ectopic fat deposition, inflammation, apoptosis, and dysregulated autophagy. All of these processes are capable of provoking the onset and development of NAFLD. To this end, it is pertinent to understand the role of ER stress in the onset and progression of NAFLD for proper management of this devastating metabolic disease. Here in this review, we will summarize available information on the recent advances in the potential role for ER stress in the etiology of NAFLD.

Low shear stress upregulates the expression of fractalkine through the activation of mitogen-activated protein kinases in endothelial cells.

: Fractalkine (FKN) is a cytokine which plays an important role in atherosclerosis and other inflammatory diseases. Studies have shown that FKN induces integrin-independent leukocyte adhesion to primary endothelial cells under physiological flow conditions. Further, increased expression of FKN has been demonstrated in atherosclerotic lesions induced by low shear stress. However, the signal transduction mechanisms involved in low shear stress-induced FKN upregulation are not well characterized. In this study, EA.hy926 cells were subjected to varying intensity of fluid shear stress for different time durations. Further, mRNA and protein expressions of FKN were assessed by quantitative real-time PCR and Western blotting, respectively. Upregulation of FKN expression, which was induced via activation of mitogen-activated protein kinases signaling pathway under conditions of low shear stress, was studied both in the presence and absence of inhibitors. Low shear stress (∼4.58 dyne/cm) for more than 1 h promoted FKN expression and activated the extracellular signal-regulated kinase (ERK)1/2, p38, and Jun N-terminal kinase (JNK) mitogen-activated protein kinases signaling pathways by their phosphorylation. Inhibitors of ERK1/2, p38, and JNK pathways downregulated the FKN expression. In this study, fluid shear stress affected FKN expression in endothelial cells via activation of ERK1/2, p38, and JNK in a time-dependent manner. Our findings serve to advance the theoretical basis for prevention and treatment of atherosclerosis.