188 research outputs found

    Evaluation of microbial products for the control of zucchini foot and root rot caused by Fusarium solani f. sp. cucurbitae race 1

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    Microbial products containing bacteria (Cedomon [Pseudomonas chlororaphis MA342, PC-MA342], Mycostop [Streptomyces sp. K61, SG-K61], Proradix®Agro [Pseudomonas sp. DSMZ13134, PS-DSMZ13134]) and fungi (Clonotry [Trichoderma harzianum and Clonostachys rosea, TH+CR], Remedier [T. asperellum ICC012 and T. gamsii ICC080, TA-ICC012+TG-ICC080], Rootshield WP [T. harzianum T22, TH-T22]) were tested for efficacy against Fusarium solani f. sp. cucurbitae race 1 (FSC7 strain) on zucchini. They were applied to seeds (S), plant growth substrate (PGS) and both (S+PGS) in a growth chamber experiment, and to PGS, transplantation soil mixture (TSM) and both (PGS+TSM) in a greenhouse experiment. FSC7 was inoculated in PGS at sowing time in the growth chamber and in TSM at transplant in the greenhouse. In the growth chamber, the most effective products were Cedomon (S and S+PGS treatments), Rootshield (PGS treatment) and Proradix (S+PGS treatment), reducing the disease by 39.7, 43.1, 25.8 and 36.4%, respectively. In the greenhouse, all tested products applied to PGS reduced the disease severity and more markedly when applied to PGS+TSM. In the PGS and PGS+TSM treatments, Cedomon was the most effective product showing a disease decrease by 42.4 and 59.5%, respectively. The data obtained in vivo were consistent with the ability of the antagonists to colonize zucchini rhizosphere and with their inhibitory effects on the growth of the pathogen in in vitro assays. The bacteria caused the greatest growth inhibition of FSC7 showing abnormal morphology, while Trichoderma spp. parasitized FSC7 hyphae. Bacteria were the most active in reducing pathogen colony growth through antibiotic metabolites. All antagonists produced exo and endochitinase enzymes. Trichoderma strains showed greater levels of β-N-acetylhexosaminidase and endochitinase, whereas SG-K61 was the most active producer of chitin 1,4-β-chitobiosidase. These results indicate that the studied bioproducts have potential for an effective management of zucchini Fusarium foot and root rot through rhizosphere competence and several mechanisms exerted by their microbial ingredients

    Evaluation of microbial products for the control of zucchini foot and root rot caused by Fusarium solani f. sp. cucurbitae race 1

    Get PDF
    Microbial products containing bacteria (Cedomon [Pseudomonas chlororaphis MA342, PC-MA342], Mycostop [Streptomyces sp. K61, SG-K61], Proradix®Agro [Pseudomonas sp. DSMZ13134, PS-DSMZ13134]) and fungi (Clonotry [Trichoderma harzianum and Clonostachys rosea, TH+CR], Remedier [T. asperellum ICC012 and T. gamsii ICC080, TA-ICC012+TG-ICC080], Rootshield WP [T. harzianum T22, TH-T22]) were tested for efficacy against Fusarium solani f. sp. cucurbitae race 1 (FSC7 strain) on zucchini. They were applied to seeds (S), plant growth substrate (PGS) and both (S+PGS) in a growth chamber experiment, and to PGS, transplantation soil mixture (TSM) and both (PGS+TSM) in a greenhouse experiment. FSC7 was inoculated in PGS at sowing time in the growth chamber and in TSM at transplant in the greenhouse. In the growth chamber, the most effective products were Cedomon (S and S+PGS treatments), Rootshield (PGS treatment) and Proradix (S+PGS treatment), reducing the disease by 39.7, 43.1, 25.8 and 36.4%, respectively. In the greenhouse, all tested products applied to PGS reduced the disease severity and more markedly when applied to PGS+TSM. In the PGS and PGS+TSM treatments, Cedomon was the most effective product showing a disease decrease by 42.4 and 59.5%, respectively. The data obtained in vivo were consistent with the ability of the antagonists to colonize zucchini rhizosphere and with their inhibitory effects on the growth of the pathogen in in vitro assays. The bacteria caused the greatest growth inhibition of FSC7 showing abnormal morphology, while Trichoderma spp. parasitized FSC7 hyphae. Bacteria were the most active in reducing pathogen colony growth through antibiotic metabolites. All antagonists produced exo- and endochitinase enzymes. Trichoderma strains showed greater levels of β-N-acetylhexosaminidase and endochitinase, whereas SG-K61 was the most active producer of chitin 1,4-β-chitobiosidase. These results indicate that the studied bioproducts have potential for an effective management of zucchini Fusarium foot and root rot through rhizosphere competence and several mechanisms exerted by their microbial ingredients

    MicroRNA-155 suppresses autophagy in chondrocytes by modulating expression of autophagy proteins

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    Objective: Autophagy dysfunction has been reported in osteoarthritis (OA) cartilage. The objective of this study was to investigate the role of microRNA-155 (miR-155), which is overexpressed in OA, in the regulation of autophagy in human chondrocytes. Design: Rapamycin (50 nM) and 2-deoxyglucose (2-DG) (5 mM) were used to stimulate autophagy in primary human articular chondrocytes and in the T/C28a2 human chondrocyte cell line. Cells were transfected with LNA GapmeR or mimic specific for miR-155 and autophagy flux was assessed by LC3 western blotting and by Cyto-ID® dye quantification in autophagic vacuoles. Expression of predicted miR-155 targets in the autophagy pathway were analyzed by real-time PCR and western blotting. Results: Autophagy flux induced by rapamycin and 2-DG was significantly increased by miR-155 LNA, and significantly decreased after miR-155 mimic transfection in T/C28a2 cells and in human primary chondrocytes. These effects of miR-155 on autophagy were related to suppression of gene and protein expression of key autophagy regulators including Ulk1, FoxO3, Atg14, Atg5, Atg3, Gabarapl1, and Map1lc3. Conclusion: MiR-155 is an inhibitor of autophagy in chondrocytes and contributes to the autophagy defects in OA

    Nutraceutical Activity in Osteoarthritis Biology: A Focus on the Nutrigenomic Role

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    Osteoarthritis (OA) is a disease associated to age or conditions that precipitate aging of articular cartilage, a post-mitotic tissue that remains functional until the failure of major homeostatic mechanisms. OA severely impacts the national health system costs and patients' quality of life because of pain and disability. It is a whole-joint disease sustained by inflammatory and oxidative signaling pathways and marked epigenetic changes responsible for catabolism of the cartilage extracellular matrix. OA usually progresses until its severity requires joint arthroplasty. To delay this progression and to improve symptoms, a wide range of naturally derived compounds have been proposed and are summarized in this review. Preclinical in vitro and in vivo studies have provided proof of principle that many of these nutraceuticals are able to exert pleiotropic and synergistic effects and effectively counteract OA pathogenesis by exerting both anti-inflammatory and antioxidant activities and by tuning major OA-related signaling pathways. The latter are the basis for the nutrigenomic role played by some of these compounds, given the marked changes in the transcriptome, miRNome, and methylome. Ongoing and future clinical trials will hopefully confirm the disease-modifying ability of these bioactive molecules in OA patients

    NOTCH1: A Novel Player in the Molecular Crosstalk Underlying Articular Chondrocyte Protection by Oleuropein and Hydroxytyrosol

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    Osteoarthritis (OA) is the most common joint disease, but no effective and safe disease-modifying treatment is available. Risk factors such as age, sex, genetics, injuries and obesity can concur to the onset of the disease, variably triggering the loss of maturational arrest of chondrocytes further sustained by oxidative stress, inflammation and catabolism. Different types of nutraceuticals have been studied for their anti-oxidative and anti-inflammatory properties. Olive-derived polyphenols draw particular interest due to their ability to dampen the activation of pivotal signaling pathways in OA. Our study aims to investigate the effects of oleuropein (OE) and hydroxytyrosol (HT) in in vitro OA models and elucidate their possible effects on NOTCH1, a novel therapeutic target for OA. Chondrocytes were cultured and exposed to lipopolysaccharide (LPS). Detailed analysis was carried out about the OE/HT mitigating effects on the release of ROS (DCHF-DA), the increased gene expression of catabolic and inflammatory markers (real time RT-PCR), the release of MMP-13 (ELISA and Western blot) and the activation of underlying signaling pathways (Western blot). Our findings show that HT/OE efficiently attenuates LPS-induced effects by firstly reducing the activation of JNK and of the NOTCH1 pathway downstream. In conclusion, our study provides molecular bases supporting the dietary supplementation of olive-derived polyphenols to revert/delay the progression of OA

    Modulation of Fatty Acid-Related Genes in the Response of H9c2 Cardiac Cells to Palmitate and n-3 Polyunsaturated Fatty Acids

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    While high levels of saturated fatty acids are associated with impairment of cardiovascular functions, n-3 polyunsaturated fatty acids (PUFAs) have been shown to exert protective effects. However the molecular mechanisms underlying this evidence are not completely understood. In the present study we have used rat H9c2 ventricular cardiomyoblasts as a cellular model of lipotoxicity to highlight the effects of palmitate, a saturated fatty acid, on genetic and epigenetic modulation of fatty acid metabolism and fate, and the ability of PUFAs, eicosapentaenoic acid, and docosahexaenoic acid, to contrast the actions that may contribute to cardiac dysfunction and remodeling. Treatment with a high dose of palmitate provoked mitochondrial depolarization, apoptosis, and hypertrophy of cardiomyoblasts. Palmitate also enhanced the mRNA levels of sterol regulatory element-binding proteins (SREBPs), a family of master transcription factors for lipogenesis, and it favored the expression of genes encoding key enzymes that metabolically activate palmitate and commit it to biosynthetic pathways. Moreover, miR-33a, a highly conserved microRNA embedded in an intronic sequence of the SREBP2 gene, was co-expressed with the SREBP2 messenger, while its target carnitine palmitoyltransferase-1b was down-regulated. Manipulation of the levels of miR-33a and SREBPs allowed us to understand their involvement in cell death and hypertrophy. The simultaneous addition of PUFAs prevented the effects of palmitate and protected H9c2 cells. These results may have implications for the control of cardiac metabolism and dysfunction, particularly in relation to dietary habits and the quality of fatty acid intake

    Hydroxytyrosol Prevents Increase of Osteoarthritis Markers in Human Chondrocytes Treated with Hydrogen Peroxide or Growth-Related Oncogene \u3b1

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    Hydroxytyrosol (HT), a phenolic compound mainly derived from olives, has been proposed as a nutraceutical useful in prevention or treatment of degenerative diseases. In the present study we have evaluated the ability of HT to counteract the appearance of osteoarthritis (OA) features in human chondrocytes. Pre-treatment of monolayer cultures of chondrocytes with HT was effective in preventing accumulation of reactive oxidant species (ROS), DNA damage and cell death induced by H2O2 exposure, as well as the increase in the mRNA level of pro-inflammatory, matrix-degrading and hypertrophy marker genes, such as iNOS, COX-2, MMP-13, RUNX-2 and VEGF. HT alone slightly enhanced ROS production, but did not enhance cell damage and death or the expression of OA-related genes. Moreover HT was tested in an in vitro model of OA, i.e. three-dimensional micromass cultures of chondrocytes stimulated with growth-related oncogene \u3b1 (GRO\u3b1), a chemokine involved in OA pathogenesis and known to promote hypertrophy and terminal differentiation of chondrocytes. In micromass constructs, HT pre-treatment inhibited the increases in caspase activity and the level of the messengers for iNOS, COX-2, MMP-13, RUNX-2 and VEGF elicited by GRO\u3b1. In addition, HT significantly increased the level of SIRT-1 mRNA in the presence of GRO\u3b1. In conclusion, the present study shows that HT reduces oxidative stress and damage, exerts pro-survival and anti-apoptotic actions and favourably influences the expression of critical OA-related genes in human chondrocytes treated with stressors promoting OA-like features

    Evidence that AMP-activated protein kinase can negatively modulate Ornithine decarboxylase activity in cardiac myoblasts

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    AbstractThe responses of AMP-activated protein kinase (AMPK) and Ornithine decarboxylase (ODC) to isoproterenol have been examined in H9c2 cardiomyoblasts, AMPK represents the link between cell growth and energy availability whereas ODC, the key enzyme in polyamine biosynthesis, is essential for all growth processes and it is thought to have a role in the development of cardiac hypertrophy. Isoproterenol rapidly induced ODC activity in H9c2 cardiomyoblasts by promoting the synthesis of the enzyme protein and this effect was counteracted by inhibitors of the PI3K/Akt pathway. The increase in enzyme activity became significant between 15 and 30min after the treatment. At the same time, isoproterenol stimulated the phosphorylation of AMPKα catalytic subunits (Thr172), that was associated to an increase in acetyl coenzyme A carboxylase (Ser72) phosphorylation. Downregulation of both α1 and α2 isoforms of the AMPK catalytic subunit by siRNA to knockdown AMPK enzymatic activity, led to superinduction of ODC in isoproterenol-treated cardiomyoblasts. Downregulation of AMPKα increased ODC activity even in cells treated with other adrenergic agonists and in control cells. Analogue results were obtained in SH-SY5Y neuroblastoma cells transfected with a shRNA construct against AMPKα. In conclusion, isoproterenol quickly activates in H9c2 cardiomyoblasts two events that seem to contrast one another. The first one, an increase in ODC activity, is linked to cell growth, whereas the second, AMPK activation, is a homeostatic mechanism that negatively modulates the first. The modulation of ODC activity by AMPK represents a mechanism that may contribute to control cell growth processes

    Antiapoptotic and Antiautophagic Effects of Eicosapentaenoic Acid in Cardiac Myoblasts Exposed to Palmitic Acid

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    Apoptosis is a programmed cell death that plays a critical role in cell homeostasis. In particular, apoptosis in cardiomyocytes is involved in several cardiovascular diseases including heart failure. Recently autophagy has emerged as an important modulator of programmed cell death pathway. Recent evidence indicates that saturated fatty acids induce cell death through apoptosis and this effect is specific for palmitate. On the other hand, n-3 polyunsaturated fatty acids (PUFAs) have been implicated in the protection against cardiovascular diseases, cardiac ischemic damage and myocardial dysfunction. In the present study we show that n-3 PUFA eicosapentaenoic acid (EPA) treatment to culture medium of H9c2 rat cardiomyoblasts protects cells against palmitate-induced apoptosis, as well as counteracts palmitate-mediated increase of autophagy. Further investigation is required to establish whether the antiautophagic effect of EPA may be involved in its cytoprotective outcome and to explore the underlying biochemical mechanisms through which palmitate and EPA control the fate of cardiac cells
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