Hepatocyte-specific mitogen-activated protein kinase phosphatase 1 in sexual dimorphism and susceptibility to alcohol induced liver injury.

Background: It is well established that females are more susceptible to the toxic effects of alcohol, although the exact mechanisms are still poorly understood. Previous studies noted that alcohol reduces the expression of mitogen-activated protein kinase phosphatase 1 (MKP1), a negative regulator of mitogen-activated protein kinases (MAPK) in the liver. However, the role of hepatocyte- specific MKP1 in the pathogenesis of alcohol-associated liver disease (ALD) remains uncharacterized. This study aimed to evaluate the role of hepatocyte-specific MKP1 in the susceptibility and sexual dimorphism in alcohol-induced liver injury. Methods: C57Bl/6 mice were used in an intragastric ethanol feeding model of alcohol-associated steatohepatitis (ASH). Hepatocyte-specific Mkp1-/- knockout and (Mkp1+/+ "f/f" male and female mice were subjected to the NIAAA chronic plus binge model. Primary mouse hepatocytes were used for in vitro studies. Liver RNA sequencing was performed on an Illumina NextSeq 500. Liver injury was evaluated by plasma alanine transaminase (ALT), hepatic ER stress and inflammation markers. Statistical analysis was carried out using ANOVA and the unpaired Student's t-test. Results: ASH was associated with the severe injury accompanied by increased endoplasmic reticulum (ER) stress and significant downregulation of Dusp1 mRNA expression. In vitro, ethanol treatment resulted in a time-dependent decrease in Dusp1 mRNA and protein expression in primary hepatocytes in both males and females; however, this effect was significantly more pronounced in hepatocytes from females. In vivo, female mice developed more liver injury in a chronic plus binge model which was accompanied by a significant decrease in liver Dusp1 mRNA expression. In comparison, liver Dusp1 was not changed in male mice, while they developed milder injury to alcohol. Mkp1 deletion in hepatocytes led to increased alcohol induced liver injury, ER stress and inflammation in both sexes. Conclusion: Hepatocyte Mkp1 plays a significant role in alcohol induced liver injury. Alcohol downregulates Mkp1 expression in hepatocytes in a sex dependent manner and could play a role in sexual dimorphism in increased female susceptibility to alcohol.

Facile modular synthesis of jasmonoyl-l-isoleucine analogs possessing a pyrazolidin-3-one core.

A short and flexible route to pyrazolidin-3-one analogs of the phytohormone (+)-7-iso-jasmonoyl-l-isoleucine is presented. The compounds were assembled from four basic building blocks, namely a pyrazolidin-3-one core, alkyl chain, linker and amino ester or acid. The efficacy of this approach was demonstrated in the synthesis of 11 analogs with variations in all parts of the molecule.

Dysregulated Cyclic Nucleotide Metabolism in Alcohol-Associated Steatohepatitis: Implications for Novel Targeted Therapies.

BACKGROUND: Cyclic nucleotides are second messengers, which play significant roles in numerous biological processes. Previous work has shown that cAMP and cGMP signaling regulates various pathways in liver cells, including Kupffer cells, hepatocytes, hepatic stellate cells, and cellular components of hepatic sinusoids. Importantly, it has been shown that cAMP levels and enzymes involved in cAMP homeostasis are affected by alcohol. Although the role of cyclic nucleotide signaling is strongly implicated in several pathological pathways in liver diseases, studies describing the changes in genes regulating cyclic nucleotide metabolism in ALD are lacking. METHODS: Male C57B/6 mice were used in an intragastric model of alcohol-associated steatohepatitis (ASH). Liver injury, inflammation, and fibrogenesis were evaluated by measuring plasma levels of injury markers, liver tissue cytokines, and gene expression analyses. Liver transcriptome analysis was performed to examine the effects of alcohol on regulators of cyclic AMP and GMP levels and signaling. cAMP and cGMP levels were measured in mouse livers as well as in livers from healthy human donors and patients with alcohol-associated hepatitis (AH). RESULTS: Our results show significant changes in several phosphodiesterases (PDEs) with specificity to degrade cAMP (Pde4a, Pde4d, and Pde8a) and cGMP (Pde5a, Pde6d, and Pde9a), as well as dual-specificity PDEs (Pde1a and Pde10a) in ASH mouse livers. Adenylyl cyclases (ACs) 7 and 9, which are responsible for cAMP generation, were also affected by alcohol. Importantly, adenosine receptor 1, which has been implicated in the pathogenesis of liver diseases, was significantly increased by alcohol. Adrenoceptors 1 and 3 (Adrb), which couple with stimulatory G protein to regulate cAMP and cGMP signaling, were significantly decreased. Additionally, beta arrestin 2, which interacts with cAMP-specific PDE4D to desensitize G-protein-coupled receptor to generate cAMP, was significantly increased by alcohol. Notably, we observed that cAMP levels are much higher than cGMP levels in the livers of humans and mice; however, alcohol affected them differently. Specifically, cGMP levels were higher in patients with AH and ASH mice livers compared with controls. As expected, these changes in liver cyclic nucleotide signaling were associated with increased inflammation, steatosis, apoptosis, and fibrogenesis. CONCLUSIONS: These data strongly implicate dysregulated cAMP and cGMP signaling in the pathogenesis of ASH. Future studies to identify changes in these regulators in a cell-specific manner could lead to the development of novel targeted therapies for ASH.

Natural γδT17 cell development and functional acquisition is governed by the mTORC2-c-Maf-controlled mitochondrial fission pathway.

Natural IL-17-producing γδ T cells (γδT17 cells) are unconventional innate-like T cells that undergo functional programming in the fetal thymus. However, the intrinsic metabolic mechanisms of γδT17 cell development remain undefined. Here, we demonstrate that mTORC2, not mTORC1, selectively controls the functional fate commitment of γδT17 cells through regulating transcription factor c-Maf expression. scRNA-seq data suggest that fetal and adult γδT17 cells predominately utilize mitochondrial metabolism. mTORC2 deficiency results in impaired Drp1-mediated mitochondrial fission and mitochondrial dysfunction characterized by mitochondrial membrane potential (ΔΨm) loss, reduced oxidative phosphorylation (OXPHOS), and subsequent ATP depletion. Treatment with the Drp1 inhibitor Mdivi-1 alleviates imiquimod-induced skin inflammation. Reconstitution of intracellular ATP levels by ATP-encapsulated liposome completely rescues γδT17 defect caused by mTORC2 deficiency, revealing the fundamental role of metabolite ATP in γδT17 development. These results provide an in-depth insight into the intrinsic link between the mitochondrial OXPHOS pathway and γδT17 thymic programming and functional acquisition.

Irreversible electroporation augments ß-glucan induced trained innate immunity for the treatment of pancreatic ductal adenocarcinoma.

BACKGROUND: Pancreatic cancer (PC) is a challenging diagnosis that is yet to benefit from the advancements in immuno-oncologic treatments. Irreversible electroporation (IRE), a non-thermal method of tumor ablation, is used in treatment of select patients with locally-advanced unresectable PC and has potentiated the effect of certain immunotherapies. Yeast-derived particulate ß-glucan induces trained innate immunity and successfully reduces murine PC tumor burden. This study tests the hypothesis that IRE may augment ß-glucan induced trained immunity in the treatment of PC. METHODS: ß-Glucan-trained pancreatic myeloid cells were evaluated ex vivo for trained responses and antitumor function after exposure to ablated and unablated tumor-conditioned media. ß-Glucan and IRE combination therapy was tested in an orthotopic murine PC model in wild-type and Rag-/- mice. Tumor immune phenotypes were assessed by flow cytometry. Effect of oral ß-glucan in the murine pancreas was evaluated and used in combination with IRE to treat PC. The peripheral blood of patients with PC taking oral ß-glucan after IRE was evaluated by mass cytometry. RESULTS: IRE-ablated tumor cells elicited a potent trained response ex vivo and augmented antitumor functionality. In vivo, ß-glucan in combination with IRE reduced local and distant tumor burden prolonging survival in a murine orthotopic PC model. This combination augmented immune cell infiltration to the PC tumor microenvironment and potentiated the trained response from tumor-infiltrating myeloid cells. The antitumor effect of this dual therapy occurred independent of the adaptive immune response. Further, orally administered ß-glucan was identified as an alternative route to induce trained immunity in the murine pancreas and prolonged PC survival in combination with IRE. ß-Glucan in vitro treatment also induced trained immunity in peripheral blood monocytes obtained from patients with treatment-naïve PC. Finally, orally administered ß-glucan was found to significantly alter the innate cell landscape within the peripheral blood of five patients with stage III locally-advanced PC who had undergone IRE. CONCLUSIONS: These data highlight a relevant and novel application of trained immunity within the setting of surgical ablation that may stand to benefit patients with PC.

Antifungal activity against anthracnose-causing species of homopterocarpin derivatives.

Derivatives of 3,9-dimethoxypterocarpan (1, homopterocarpin) were prepared by nitration, amination, and oxidation reactions, among others, and their antifungal activity was evaluated against the phytopathogenic fungi Colletotrichum gloeosporioides and C. lindemuthianum. Derivatives were purified by chromatographic techniques and identified by nuclear magnetic resonance spectroscopy. Eight derivatives were obtained from 1 corresponding to 3,9-dimethoxy-8-nitropterocarpan (2), 3,9-dimethoxy-2,8-dinitropterocarpan (3), 3,9-dimethoxy-2,8,10-trinitropterocarpan (4), 2,8-diamino-3,9-dimethoxypterocarpan (5), 3,9-dimethylcoumestan (6), medicarpin (7), 2'-hydroxy-4-(2-hydroxyethylsulfanyl)-7,4'-dimethoxyisoflavan (8), and 4-(2-hydroxyethylsulfanyl)-7,2',4'-trimethoxyisoflavan (9). The in vitro antifungal activity of the derivatives was determined at concentrations between 35 and 704 µM. Compounds 7 and 8 at 704 µM, showed an inhibition of radial growth and spore germination close to 100%, exceeding that found for the starting compound 1, which was 46%. Growth inhibition assays were also performed for the derivative 8 on papaya fruits (Carica papaya L. cv. Hawaiana) and mango (Mangifera indica L. cv. Hilacha) infected with C. gloeosporioides. Compound 8 showed fungal growth inhibition in fruits higher than that found for 1 and thymol (a recognized natural antifungal), under the same conditions. In general, derivatives that exhibited greater antifungal activity correspond to the compounds containing hydroxyl groups in the structure. Some of the compounds obtained could be considered promising for the control of phytopathogenic fungi.

Screening of Indanoyl-Type Compounds as Elicitors of Isoflavonoid Phytoalexins in Colombian Common Bean Cultivars.

Eleven indanoyl derivatives were synthesized and, along with methyl jasmonate, evaluated as isoflavonoid-phytoalexin elicitors in two cultivars of common bean (Phaseolus vulgaris L. cvs. ICA-Cerinza and Uribe Rosado, tolerant and susceptible to anthracnose, respectively). Indanoyl derivatives (an ester, two amides, and eight indanoyl-amino acid conjugates) were obtained from 1-oxo-indane-4-carboxylic acid. In general, the accumulation of isoflavonoid-type phytoalexins, such as isoflavones (genistein, daidzein, and 2'-hydroxygenistein), isoflavanones (dalbergioidin and kievitone), isoflavan (phaseollinisoflavan), coumestrol, and pterocarpans (phaseollidin and phaseollin), was dependent on the common bean cultivar, the post-induction time, and the elicitor structure. Isoflavones, dalbergioidin, and coumestrol reached their highest amounts during the first 48 to 72 h, whereas kievitone, phaseollinisoflavano, and the pterocarpans reached maximum levels between 72 and 96 h. The 1-oxo-indanoyl-L-isoleucine methyl ester elicited the highest levels of phytoalexins (similar to those elicited by the methyl jasmonate) and showed no significant phytotoxic effects on common bean seedlings. The indanoyl-type synthetic elicitor, 1-oxo-indanoyl-L-isoleucine methyl ester, may represent a promising agronomic alternative for disease control in common bean by enhancing the accumulation of antimicrobial isoflavonoid phytoalexins.

Antibacterial and hemolytic activity of extracts and compounds obtained from epicarps and seeds of Garcinia madruno(Kunth) Hammel / Actividad antimicrobiana y hemolítica de extractos y compuestos obtenidos del epicarpio y las semillas de Garcinia madruno (Kunth) Hammel

This paper describes the evaluation of the antimicrobial and hemolytic activity of the hexane, dichloromethane, ethyl acetate and methanol extracts from seeds and epicarps of Garcinia madruno; as well garcinol, morelloflavone and volkensiflavone isolated from the same species. In the preliminary test of bacterial susceptibility, hexane extracts from seeds and epicarps and the three compounds tested only displayed inhibitory growth effect against Gram-positive bacteria. The minimum inhibitory concentrations of extract and compounds ranging from 86.6 to 1253.4 µg/mL. The hemolytic activity was assessed; however, except for the methanol extract from seeds, none of the samples studied induced hemolysis. Thus, our results suggest that extracts and compounds from G. madruno have the potential to be used in the control of pathologies associated to Gram-positive bacteria. This is the first report of the antimicrobial and hemolytic activity of extracts of different polarity obtained from seeds and epicarps of this edible species.

El presente artículo describe la evaluación de la actividad antimicrobiana y hemolítica de los extractos de hexano, diclorometano, acetato de etilo y metanol, obtenidos de la semilla y el epicarpio de Garcinia madruno; así como de garcinol, morelloflavona y volkensiflavona; aislados de la misma especie. En el ensayo de susceptibilidad bacteriana, tanto el extracto de hexano obtenido a partir de la semilla y el epicarpio, y los tres compuestos aislados, únicamente mostraron actividad inhibitoria del crecimiento contra bacterias Gram-positivas. La concentración mínima inhibitoria presentó valores entre 86.6 y 1253.4 µg/mL. También se estableció la actividad hemolítica; sin embargo, con excepción del extracto metanólico obtenido a partir de las semillas, ninguna de las muestras evaluadas indujo hemólisis. Por lo tanto, los resultados sugieren que los extractos y compuestos de G. madruno tienen el potencial de ser usados en el control de bacterias Gram-positivas asociadas a diversas patologías. Este es el primer reporte de actividad antimicrobiana y hemolítica de extractos de diferente polaridad obtenidos de las semillas y epicarpios de esta especie comestible.

Elicitation of isoflavonoids in Colombian edible legume plants with jasmonates and structurally related compounds.

Common bean (Phaseolus vulgaris L.), soybean (Glycine max L.) and mung bean (Vigna radiata L. Wilczek) seedlings were treated with methyl jasmonate (MeJA); then, dose-response and time-course experiments were carried out. Isoflavonoid composition was evaluated by high performance liquid chromatography. As a result of MeJA induction, all leguminous plants increase the amount of isoflavonoids, at levels that depend on the concentration of the elicitor and the time after induction. However, the application of MeJA in concentrations higher than 2.22 mM showed deleterious effects on seedlings and strong decreases in the concentration of isoflavonoids. In addition, a series of compounds structurally related to MeJA, such as jasmonic acid, cis-jasmone, coronatine, and indanoyl derivatives, were evaluated as elicitors. The results show that coronatine and the indanoyl-amino acids conjugates displayed a significant elicitor effect of isoflavonoids in common bean (cvs. Cargamanto Mocho and Corpoica LAS 106) and soybean (cv. Soyica P-34) seedlings, even higher than that found with the recognized elicitors, benzo (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester (acibenzolar S-methyl) and benzo-(1,2,3) thiadiazole-7-carbothioic acid (acibenzolar acid). Leguminous plants can be treated with jasmonates and indanoyl derivatives to increase levels of bioactive isoflavonoids and consequently improve biological and functional properties and resistance against pests.

Coumaro-chalcones synthesized under solvent-free conditions as potential agents against malaria, leishmania and trypanosomiasis.

Leishmaniasis, trypanosomiasis, and malaria are a group of neglected tropical diseases present in tropical regions and they affect large numbers of people in developing countries. A series of thirteen coumaro-chalcones (A1-A13) were synthesized under solvent-free conditions and their in vitro anti-leishmanial, anti-plasmodial, anti-trypanosomal and cytotoxic activities were evaluated. One of these coumaro-chalcones, 3-[(2E)-3-(3-ethoxy-4-hydroxyphenyl)prop-2-enoyl]-2H-chromen-2-one (A12), is a new compound. Compounds 3-[(2E)-3-(3-hydroxyphenyl)prop-2-enoyl]-2H-chromen-2-one (A5), 3-[(2E)-3-(3-methoxyphenyl)prop-2-enoyl]-2H-chromen-2-one (A2) and 3-[(2E)-3-phenylprop-2-enoyl]-2H-chromen-2-one (A1) displayed strong inhibition against intracellular amastigotes of Leishmania panamensis with EC50 of 2.1 ± 0.1, 2.5 ± 0.2 and 3.7 ± 0.5 µM, respectively. In addition, Plasmodium falciparum was moderately inhibited by the coumarin-chalcone hybrids, particularly A12 (EC50: 15.0 ± 0.5 µM) and 3-[(2E)-3-(1,3-benzodioxol-5-yl)prop-2-enoyl]-2H-chromen-2-one (A13) (EC50: 15.2 ± 1.1 µM). Remarkably, the coumaro-chalcone A5 (EC50: 18.7 ± 2.4 µM) exhibited an inhibition of the Trypanosoma cruzi intracellular amastigotes similar to the commercial drug Benznidazole (EC50: 14.5 ± 0.1 µM). These results support the therapeutic potential of coumaro-chalcone hybrids.

Tumor-derived exosomes drive immunosuppressive macrophages in a pre-metastatic niche through glycolytic dominant metabolic reprogramming.

One of the defining characteristics of a pre-metastatic niche, a fundamental requirement for primary tumor metastasis, is infiltration of immunosuppressive macrophages. How these macrophages acquire their phenotype remains largely unexplored. Here, we demonstrate that tumor-derived exosomes (TDEs) polarize macrophages toward an immunosuppressive phenotype characterized by increased PD-L1 expression through NF-kB-dependent, glycolytic-dominant metabolic reprogramming. TDE signaling through TLR2 and NF-κB leads to increased glucose uptake. TDEs also stimulate elevated NOS2, which inhibits mitochondrial oxidative phosphorylation resulting in increased conversion of pyruvate to lactate. Lactate feeds back on NF-κB, further increasing PD-L1. Analysis of metastasis-negative lymph nodes of non-small-cell lung cancer patients revealed that macrophage PD-L1 positively correlates with levels of GLUT-1 and vesicle release gene YKT6 from primary tumors. Collectively, our study provides a novel mechanism by which macrophages within a pre-metastatic niche acquire their immunosuppressive phenotype and identifies an important link among exosomes, metabolism, and metastasis.

Increased accumulation of isoflavonoids in common bean (Phaseolus vulgaris L.) tissues treated with 1-oxo-indane-4-carboxylic acid derivatives.

Isoflavonoid phytoalexins (isoflavones: genistein, 2'-hydroxygenistein, and daidzein; isoflavanones: dalbergioidin and kievitone; coumestrol; pterocarpans: phaseollidin and phaseollin; and the isoflavan: phaseollinisoflavan) production in response to the application of eleven 1-oxo-indane-4-carboxylic acid derivatives (indanoyl esters and indanoyl amino acids conjugates), in cotyledons and hypocotyl/root of two common bean (Phaseolus vulgaris L.) cultivars was evaluated. The content of isoflavonoids depended on the cultivar, the treated tissue, the time after induction, the structure and concentration of the elicitor. The highest isoflavonoid contents were found when 1-oxo-indanoyl-amino acids conjugates were used as elicitors. Cotyledons and hypocotyl/root of the anthracnose-resistant cultivar produced significantly higher isoflavonoid contents as compared to the susceptible one. Maximum levels of phaseollin were obtained using 0.66 mM 1-oxo-indanoyl-l-isoleucyl methyl ester and between 72 and 96 h post-induction. So, 1-oxo-indane-4-carboxylic acid derivatives, may be used to enhance the amount of isoflavonoid phytoalexins in common bean and protect crops from phytopathogenic microorganisms.

Perinaphthenone and derivatives as control agents of phytopathogenic fungi: fungitoxicity and metabolism.

Metabolism and in vitro fungitoxicity of perinaphthenone against three economically important fungi of the citrus, Botryodiplodia spp., Botrytis spp. and Fusarium spp. were investigated. Perinaphthenone exhibited significant antifungal activity at 62.5 µM and above. Even, the inhibitory effect against Fusarium spp. was significantly enhanced by exposure to direct light. In addition, the metabolism of perinaphthenone by the three fungi was studied. Results show that perinaphthenone was transformed almost completely during the first 24 h; two major products, whose concentration increased progressively during the twelve days of the test, were isolated and identified as 2,3-dihydro-1H-phenalen-1-ol and 2,3-dihydro-phenalen-1-one. Although both metabolic products displayed a considerable fungistatic effect, their slightly lower activities in comparison to perinaphthenone indicate that the transformation was a detoxification process. Studies on the relationship between the effect of some substituents in the perinaphthenone core and the mycelial growth inhibition of Botryodiplodia spp. were also carried out. Results show that the α, ß-unsaturated carbonyl system is an important structural requirement but not the only to be necessary for the strong antifungal activity of perinaphthenone. In general, the antifungal properties of perinaphthenone may be modulated through the incorporation of substituents in the naphthalene core or in the α, ß-unsaturated carbonyl system. It is concluded that perinaphthenone could be used as an antifungal agent or as a structural template for the development of new fungicide compounds.

Controlling anthracnose by means of extracts, and their major constituents, from Brosimum rubescens Taub.

Anthracnose, caused by the fungus Colletotrichum gloeosporioides (Penz.) Penz. & Sacc., is the most limiting fungal disease of mango and papaya crops in Colombia. The in vivo and in vitro activity against C. gloeosporioides of the extracts from sawdust of Brosimum rubescens Taub. (Moraceae) was evaluated. The extracts of less polarity (n-hexane and dichloromethane) displayed the greatest inhibitory effects. Then, the coumarins xanthyletin (2.74 % d.w.) and 7-demethylsuberosin (2.19 % d.w.) were isolated from these extracts. The compound 7-demethylsuberosin displayed a strong in vivo and in vitro antifungal activity. Furthermore, the metabolism of 7-demethylsuberosin by the fungus C. gloeosporioides was analyzed. The fungus slowly detoxified 7-demethylsuberosin to marmesin and decursinol. Therefore, the high antifungal activity and low level of detoxification make 7-demethylsuberosin, and the extracts that contain it, promising candidates for controlling C. gloeosporioides. Sawdust of B. rubescens may be considered a valuable source of extracts and coumarins with antifungal activity.

A selective thioxothiazolidin-coumarin probe for Hg2+ based on its desulfurization reaction. Exploring its potential for live cell imaging.

Sensing the most toxic heavy metal (mercury) has attracted a lot of attention in recent years due to its extreme harmfulness to both human health and the environment. Thus, we reported herein the synthesis, spectroscopic and kinetic characterization, and biological evaluation of a new thioxothiazolidin coumarin derivative (ILA92), which undergoes a desulfurization reaction induced by mercuric ions (Hg2+). This process is the origin of a selective sensing of Hg2+ ions in aqueous solution by colorimetric and fluorescent methods. Furthermore, the probe showed great potential for imaging Hg2+ in living cells.

Coumarins from the peel of citrus grown in Colombia: composition, elicitation and antifungal activity.

The present work analyses the chromatographic profile of the peels from fruits of different citrus cultivated in Colombia: sweet orange (Citrus sinensis [L.] Osbeck var. Valencia), mandarins (Citrus reticulata L. var. Arrayana and Oneco), Key lime (Citrus aurantifolia [Christ.] Swingle var. Pajarito), Mandarine lime (Citrus x limonia, a hybrid between Citrus reticulata and Citrus x limon) and Tahitian lime (C. latifolia Tanaka, syn. Persian lime). Coumarins, furanocoumarins and polymethoxylated flavones are the major compounds. Then, six coumarins were isolated and identified from fruits of Tahitian and Key lime corresponding to 5-geranyloxy-7-methoxycoumarin; 5,7-dimethoxycoumarin (syn. limettin); 5,8-dimethoxypsoralen (syn. isopimpinellin); 5-methoxypsoralen (syn. bergaptene); 5-geranoxypsoralen (syn. bergamottin) and 5-(2,3-dihydroxy-3-methylbutoxy) psoralen (syn. oxypeucedanin hydrate). Coumarins and furanocoumarins were quantified by liquid chromatography (HPLC-DAD). Results show that the prenylated compounds were present in high concentrations in Tahitian and Key lime but in very low amounts in mandarins and sweet orange. Subsequently, the antifungal activity (inhibition of mycelial growth and germination of spores) of the coumarins against the fungus causing the anthracnose, Colletotrichum sp. (isolated from aerial parts of Tahitian lime) was determined. The compounds limettin and bergaptene, as well as mixtures of them, showed significant inhibitory effect (radial growth and spore germination) when compared to the control. Finally, the effect of some recognized elicitors to induce the coumarin production in fruits of C. latifolia was evaluated. The results showed that the chemical profiles are dependent on the applied elicitor and the post-induction time. As a result of the induction, a high concentration of some coumarins and furanocoumarins was maintained in the course of time for the Tahitian lime. In conclusion, isolated coumarins could be involved in the defense mechanisms of C. latifolia, C. aurantifolia and C. limonia and their accumulation may be modulated by the application of elicitors.

Isoflavonoid composition and biological activity of extracts from soybean seedlings treated by different elicitors.

Time-course and dose-response experiments were carried out to establish the ability for synthesizing isoflavonoids of soybean seedlings (cv. Soyica P34) treated with salicylic (SA) and isonicotinic acids (INA). Then, 25 structurally-related compounds were evaluated for their isoflavonoid-eliciting activity. Next, the antimicrobial and antioxidant activities of EtOAc-soluble fraction from soybean seedlings treated with some synthetic elicitors were determined. Results showed that the concentration of isoflavonoids in soybean seedlings was significantly increased by the application of SA and INA. The major isoflavonoids detected were the malonyl-glycosidic isoflavones, followed by genistin and daidzin. The isoflavone aglycones (genistein, daidzein, and formononetin), coumestrol and glyceollins were found in lower concentrations. Maximum accumulation of glyceollins was detected after 48 and 144 h in soybean seedlings treated with 1.6 mM INA and SA, respectively. EtOAc-extracts from soybean seedlings treated with two structurally-related compounds to INA displayed a significant antimicrobial and antioxidant activity. Therefore, INA, SA and structurally-related compounds can be used to increase the amounts of natural antioxidant or antimicrobial compounds in soybean, either to protect the plant directly against pathogens or as a natural source for subsequent isolation of isoflavonoids or bioactive extracts, which have potential application in functional foods or pharmaceutical and personal care products.

ZEB1 Regulates Multiple Oncogenic Components Involved in Uveal Melanoma Progression.

Human uveal melanoma (UM) is a major ocular malignant tumor with high risk of metastasis and requires multiple oncogenic factors for progression. ZEB1 is a zinc finger E-box binding transcription factor known for participating epithelial-mesenchymal transition (EMT), a critical cellular event for metastasis of malignant tumors of epithelium origin. ZEB1 is also expressed in UM and high expression of ZEB1 correlates with UM advancement, but has little effect on cell morphology. We show that spindle UM cells can become epithelioid but not vice versa; and ZEB1 exerts its tumorigenic effects by promoting cell dedifferentiation, proliferation, invasiveness, and dissemination. We provide evidence that ZEB1 binds not only to repress critical genes involving in pigment synthesis, mitosis, adherent junctions, but also to transactivate genes involving in matrix degradation and cellular locomotion to propel UM progression towards metastasis. We conclude that ZEB1 is a major oncogenic factor required for UM progression and could be a potential therapeutic target for treating UM in the clinic.

Antifungal activity against colletotrichum acutatum and colletotrichum gloeosporioides of the major constituents from wood sawdust of platymiscium gracile benth / Actividad antifúngica contra colletotrichum acutatum y colletotrichum gloeosporioides de los constituyentes mayoritarios del aserrín de madera de platymiscium gracile benth

The tree tomato (Solanum betaceum Cav., Solanaceae) anthracnose, caused by the fungi Colletotrichum acutatum and Colletotrichum gloeosporioides, is the most important disease of this crop in Colombia for its wide distribution and the losses it causes. In the present work, the in vitro antifungal activity of the soluble fractions in n-hexane, dichloromethane, and ethyl acetate, and their major constituents from the sawdust of timber specie Platymiscium gracile Benth. (Fabaceae) against both fungi was evaluated. The n-hexane-soluble fraction exhibited the greatest inhibitory effect. The metabolites homopterocarpin (a pterocarpan, 0.39 percent dry weight), calycosin (an isoflavone, 2.01 percent) and scoparone (a coumarin, 1.48 percent) were isolated for the first time from wood sawdust of P. gracile. The structure of these compounds was determined by 1H and 13C NMR analyses. The three compounds tested showed significant antifungal activity.

La antracnosis del tomate de árbol (Solanum betaceum Cav., Solanaceae), ocasionada por los hongos Colletotrichum acutatum y Colletotrichum gloeosporioides, es la enfermedad más importante de este cultivo en Colombia por su amplia distribución y las pérdidas que ocasiona. En el presente trabajo se evaluó la actividad antifúngica in vitro de las fracciones solubles en n-hexano, diclorometano y acetato de etilo, y sus componentes mayoritarios, del aserrín de la especie maderable Platymiscium gracile Benth. (Fabaceae), contra ambos hongos. La fracción en n-hexano exhibió el mayor efecto inhibitorio. Los metabolitos homopterocarpina (un pterocarpano; 0.39 por ciento del peso seco de aserrín), calicosin (una isoflavona; 2.01 por ciento) y escoparona (una cumarina; 1.48 por ciento) se aislaron por primera vez desde el aserrín de madera de P. gracile empleando técnicas cromatográficas. La estructura de los compuestos se determinó por análisis de RMN de 1H y 13C. Los tres metabolitos mostraron una actividad antifúngica significativa contra ambos hongos.

LINE-1 silencing by retinoblastoma proteins is effected through the nucleosomal and remodeling deacetylase multiprotein complex.

BACKGROUND: Long Interspersed Nuclear Element-1 (L1) is an oncogenic mammalian retroelement silenced early in development via tightly controlled epigenetic mechanisms. We have previously shown that the regulatory region of human and murine L1s interact with retinoblastoma (RB) proteins to effect retroelement silencing. The present studies were conducted to identify the corepressor complex responsible for RB-mediated silencing of L1. METHODS: Chromatin immunoprecipitation and silencing RNA technology were used to identify the repressor complex that silences L1 in human and murine cells. RESULTS: Components of the Nucleosomal and Remodeling Deacetylase (NuRD) multiprotein complex specifically enriched the L1 5'-untranslated DNA sequence in human and murine cells. Genetic ablation of RB proteins in murine cells destabilized interactions within the NuRD macromolecular complex and mediated nuclear rearrangement of Mi2-ß, an ATP-dependent helicase subunit with nucleosome remodeling activity. Depletion of Mi2-ß, RbAP46 and HDAC2 reduced the repressor activity of the NuRD complex and reactivated a synthetic L1 reporter in human cells. Epigenetic reactivation of L1 in RB-null cells by DNA damage was markedly enhanced compared to wild type cells. CONCLUSIONS: RB proteins stabilize interactions of the NuRD corepressor complex within the L1 promoter to effect L1 silencing. L1 retroelements may serve as a scaffold on which RB builds heterochromatic regions that regulate chromatin function.