Longevity of Oncidium varicosum (Orchidaceae) inflorescences treated with 1-methylciclopropene

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da qualidade de manga 'palmer' tratada com 1-metilciclopropeno e armazenada sob refrigeração e condição ambiente

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Conservação pós-colheita de manga 'Tommy Atkins' com 1-metilciclopropeno

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Controle do amadurecimento de banana 'Prata-Anã' armazenada sob refrigeração e atmosfera modificada passiva com o uso do 1-metilciclopropeno

O 1- Metilciclopropeno (1-MCP) é um produto inovador que inibe a ação do etileno em vegetais, retardando o início do amadurecimento de pomáceas, frutas de caroço e frutas tropicais. Com este trabalho objetivou-se avaliar a eficiência de diferentes concentrações do 1-MCP no controle do amadurecimento de bananas 'Prata-Anã' produzidas no Norte de Minas Gerais, armazenadas a 12°C e 95% de UR sob atmosfera modificada passiva. Os cachos foram colhidos no grau 1 de coloração da casca, que corresponde ao estádio verde de maturação. Foram utilizadas somente as segundas pencas dos cachos selecionados e estas foram separadas em buquês de 4 frutos. Cada parcela constou de 4 repetições e cada repetição 1 buquê. As concentrações do 1-MCP aplicadas foram: 0, 30, 60 e 90 ppb. Os frutos foram acondicionados em bandejas de isopor e embalados em filme de PVC de 15 micras, armazenados a 12°C e 95% de UR, sendo avaliados aos 10, 15, 20, e 25 dias. As avaliações realizadas constaram de diâmetro, grau de coloração da casca, firmeza, sólidos solúveis, acidez titulável e pH. A aplicação do 1-MCP foi eficaz em retardar o amadurecimento de bananas 'Prata-Anã' cultivadas na região Norte de Minas Gerais. As concentrações de 30, 60 e 90 ppb não apresentaram efeito diferenciado quanto às características avaliadas, podendo ser utilizada a concentração de 30 ppb, com economia do produto, obtendo-se os mesmos benefícios das concentrações de 60 e 90 ppb.

Firmeza de mangas 'Palmer' tratadas com 1-metilciclopropeno e armazenadas sob refrigeração

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Protective effects of the galectin-1 protein on in vivo and in vitro models of ocular inflammation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Gibberellic acid, ozone and 1-methylcyclopropene on the gray mold control in avant garde rose

Gray mold caused by Botrytis cinerea is considered the major disease of greenhouse grown flowers. The goal of this study was to evaluate the effects of gibberellic acid (GA3), ozone, and 1-MCP, applied on postharvest, on the gray mold control in 'Avant Garde' rose. Rose flowers were artificially inoculated with B. cinerea (104 conidia ml-1) and non-inoculated. After treatments, roses were stored under room conditions (20±2°C/80±5% RH) and checked for gray mold incidence and severity. Spraying of GA3 at 25, 50, and 75 mg L-1 on non-inoculated roses reduced the area under the disease progress curve (AUDPC) of gray mold incidence in 41, 40 and 54%, respectively. Continuous application of ozone at 2.7 ppm reduced 14-folds B. cinerea sporulation. On the other hand, 1-MCP did not control gray mould in rose. These results showed that GA3 sprays and ozone contribute to postharvest control of gray mold in cut rose and can be utilized on integrated disease management.

Lisianthus vase life after 1-methylcyclopropene and salicylic acid postharvest treatment

This study evaluated the effects of application of 0.5 µl L-1 1-methyl-cyclopropene (1-MCP), 1000 mg L-1 salicylic acid (SA) and the interaction between the two products at room temperature and pre-exposure at 9±2°C for 24 h in maintaining postharvest quality of lisianthus flowers. After applying the treatment, the flowers were kept in jars with water, stored at 24±2°C. The SA treatments proved ineffective, presenting symptoms of phytotoxicity, with high rate of bent neck and yellowing of petals, both at room temperature and in cold storage, and propitiate the emergence of pathogens. The association between 1-MCP in pre-exposure to 9±2°C for 24 h increased the durability of the stems in six days compared to the control treatment, with less symptoms of bent neck and swelling of stems.

Elevated systemic monocyte chemoattractrant protein-1 in hepatic steatosis without significant hepatic inflammation

Non-alcoholic fatty liver disease (NAFLD) is strongly associated with obesity and the metabolic syndrome. It encompasses a clinico-pathologic spectrum of conditions ranging from simple steatosis to nonalcoholic steatohepatitis (NASH). The latter develops upon pro-inflammatory cell infiltration and is widely considered as the first relevant pathophysiological step in NAFLD-progression. The chemokine monocyte chemoattractant protein 1 (MCP-1) plays an important role in the progression of hepatic inflammation and fibrosis, and both increased hepatic expression and circulating serum levels have been described in NASH. Here, we aimed to investigate MCP-1 expression in simple hepatic steatosis. Upon feeding a high-fat diet mice developed hepatic steatosis in the absence of significant hepatic inflammation, but elevated hepatic MCP-1 expression compared to control mice fed a standard chow. Interestingly, high-fat diet fed mice had significantly higher MCP-1 serum levels, and MCP-1 mRNA expression was significantly increased in visceral adipose tissue. Furthermore, MCP-1 serum levels were also elevated in patients with ultrasound-diagnosed NAFLD and correlated with the body-mass index and fasting glucose. In conclusion, our data indicate both the liver and adipose tissue as cellular sources of elevated circulating MCP-1 levels already in the early phase of hepatic steatosis. Since MCP-1 derived from visceral adipose tissue reaches the liver via portal circulation at high concentrations it may significantly contribute to the progression of simple steatosis to NASH.

Plasminogen activator inhibitor-1, monocyte chemoattractant protein-1, e-selectin and C-reactive protein levels in response to 4-week very-high-fructose or -glucose diets.

BACKGROUND/OBJECTIVES High intake of added sweeteners is considered to have a causal role in the pathogenesis of cardiometabolic disorders. Especially, high-fructose intake is regarded as potentially harmful to cardiometabolic health. It may cause not only weight gain but also low-grade inflammation, which represents an independent risk factor for developing type 2 diabetes and cardiovascular disease. In particular, fructose has been suggested to induce plasminogen activator inhibitor-1 (PAI-1) expression in the liver and to increase circulating inflammatory cytokines. We therefore aimed to investigate, whether high-fructose diet has an impact on PAI-1, monocyte chemoattractant protein-1 (MCP-1), e-selectin and C-reactive protein (CRP) concentrations in healthy humans. SUBJECTS/METHODS We studied 20 participants (12 males and 8 females) of the TUebingen FRuctose Or Glucose study. This is an exploratory, parallel, prospective, randomized, single-blinded, outpatient, hypercaloric, intervention study. The participants had a mean age of 30.9 ± 2.1 years and a mean body mass index of 26.0 ± 0.5 kg/m(2) and they received 150 g of either fructose or glucose per day for 4 weeks.Results:There were neither significant changes of PAI-1, MCP-1, e-selectin and CRP after fructose (n=10) and glucose (n=10) intervention nor treatment effects (all P>0.2). Moreover, we did not observe longitudinal associations of the inflammatory parameters with triglycerides, liver fat, visceral fat and body weight in the fructose group. CONCLUSIONS Temporary high-fructose intake does not seem to cause inflammation in apparently healthy people in this secondary analysis of a small feeding trial.

HIV-1 Tat protein mimicry of chemokines

The HIV-1 Tat protein is a potent chemoattractant for monocytes. We observed that Tat shows conserved amino acids corresponding to critical sequences of the chemokines, a family of molecules known for their potent ability to attract monocytes. Synthetic Tat and a peptide (CysL24–51) encompassing the “chemokine-like” region of Tat induced a rapid and transient Ca2+ influx in monocytes and macrophages, analogous to β-chemokines. Both monocyte migration and Ca2+ mobilization were pertussis toxin sensitive and cholera toxin insensitive. Cross-desensitization studies indicated that Tat shares receptors with MCP-1, MCP-3, and eotaxin. Tat was able to displace binding of β-chemokines from the β-chemokine receptors CCR2 and CCR3, but not CCR1, CCR4, and CCR5. Direct receptor binding experiments with the CysL24–51 peptide confirmed binding to cells transfected with CCR2 and CCR3. HIV-1 Tat appears to mimic β-chemokine features, which may serve to locally recruit chemokine receptor-expressing monocytes/macrophages toward HIV producing cells and facilitate activation and infection.

Specific Activation of Leukocyte β2 Integrins Lymphocyte Function–associated Antigen-1 and Mac-1 by Chemokines Mediated by Distinct Pathways via the α Subunit Cytoplasmic Domains

We show that CC chemokines induced a sustained increase in monocyte adhesion to intercellular adhesion molecule-1 that was mediated by Mac-1 (αMβ2) but not lymphocyte function–associated antigen-1 (LFA-1; αLβ2). In contrast, staining for an activation epitope revealed a rapid and transient up-regulation of LFA-1 activity by monocyte chemotactic protein-1 (MCP-1) in monocytes and Jurkat CCR2 chemokine receptor transfectants or by stromal-derived factor-1α in Jurkat cells. Differential kinetics for activation of Mac-1 (sustained) and LFA-1 (transient) avidity in response to stromal-derived factor-1α were confirmed by expression of αM or αL in αL-deficient Jurkat cells. Moreover, expression of chimeras containing αL and αM cytoplasmic domain exchanges indicated that α cytoplasmic tails conferred the specific mode of regulation. Coexpressing αM or chimeras in mutant Jurkat cells with a “gain of function” phenotype that results in constitutively active LFA-1 demonstrated that Mac-1 was not constitutively active, whereas constitutive activity was mediated via the αL cytoplasmic tail, implying the presence of distinct signaling pathways for LFA-1 and Mac-1. Transendothelial chemotaxis of monocytes in response to MCP-1 was dependent on LFA-1; however, Mac-1 was involved at MCP-1 concentrations stimulating its avidity, showing differential contributions of β2 integrins. Our data suggest that a specific regulation of β2 integrin avidity by chemokines may be important in leukocyte extravasation and may be triggered by distinct activation pathways transduced via the α subunit cytoplasmic domains.

The cis-acting phorbol ester "12-O-tetradecanoylphorbol 13-acetate"-responsive element is involved in shear stress-induced monocyte chemotactic protein 1 gene expression.

Vascular endothelial cells, serving as a barrier between vessel and blood, are exposed to shear stress in the body. Although endothelial responses to shear stress are important in physiological adaption to the hemodynamic environments, they can also contribute to pathological conditions--e.g., in atherosclerosis and reperfusion injury. We have previously shown that shear stress mediates a biphasic response of monocyte chemotactic protein 1 (MCP-1) gene expression in vascular endothelial cells and that the regulation is at the transcriptional level. These observations led us to functionally analyze the 550-bp promoter region of the MCP-1-encoding gene to define the cis element responding to shear stress. The shear stress/luciferase assay on the deletion constructs revealed that a 38-bp segment (-53 to -90 bp relative to the transcription initiation site) containing two divergent phorbol ester "12-O-tetradecanoylphorbol 13-acetate" (TPA)-responsive elements (TRE) is critical for shear inducibility. Site-specific mutations on these two sites further demonstrated that the proximal one (TGACTCC) but not the distal one (TCACTCA) was shear-responsive. Shear inducibility was lost after the mutation or deletion of the proximal site. This molecular mechanism of shear inducibility of the MCP-1 gene was functional in both the epithelial-like HeLa cells and bovine aortic endothelial cells (BAEC). In a construct with four copies of the TRE consensus sequences TGACTACA followed by the rat prolactin minimal promoter and luciferase gene, shear stress induced the reporter activities by 35-fold and 7-fold in HeLa cells and BAEC, respectively. The application of shear stress on BAEC also induced a rapid and transient phosphorylation of mitogen-activated protein kinases. Pretreatment of BAEC with TPA attenuated the shear-induced mitogen-activated protein kinase phosphorylation, suggesting that shear stress and TPA share a similar signal transduction pathway in activating cells. The present study provides a molecular basis for the transient induction of MCP-1 gene by shear stress.

A simple sustained release device for the ethylene binding inhibitor 1-methylcyclopropene

The efficacy of 1-methylcyclopropene (1-MCP) gas to prevent the adverse effects of ethylene is limited by its short-term residual activity in some plants. Development of a simple 1-MCP sustained release device that prolongs 1-MCP exposure is reported herein. Sustained release devices comprised of polyvinylchloride tubes containing 0.1 g SmartFresh(TM) powder (a.i. 3.3% 1-MCP) and 1.25 ml deionised water were used to release 1-MCP into fibreboard cartons containing cut Geraldton waxflower (Chamelaucium uncinatum Schauer) cv. CWA Pink bunches during export shipment by air (107 h) from Australia to the UK. The devices protected flowers against abscission induced by subsequent test exposures to ethylene (1011,mul l(-1), 12 h, 20 degreesC) for 3-5 days after arrival. In contrast, pre-shipment treatments with either a single application of 790 nl l(-1) 1-MCP for 14 h at 2 degreesC or a 0.2 mM Ag+ (as silver thiosulphate; STS) pulse for 14 h at 2 degreesC protected flowers against exogenous ethylene for only 1-2 days of post-export life. However, pre-shipment 1-MCP fumigation was up to about three-fold more effective than either sustained 1-MCP release or pre-shipment STS treatments in reducing floral organ and leaf abscission from bunches during export. Thus, it is suggested that a combination of pre-shipment 1-MCP fumigation before export with sustained 1-MCP release during shipment should maximise efficacy against ethylene-induced waxflower flower abscission. (C) 2004 Elsevier B. V. All rights reserved.

Manipulating avocado fruit ripening with 1-methylcyclopropene

Previous investigations with 1-methylcyclopropene (1-MCP) on avocado (Persea americana Mill.) fruit have focussed mainly on improving storage life by reducing the severity of disorders causing discolouration of the flesh. Development of 1-MCP and ethylene treatments, which also help control the time to reach the eating ripe stage, may confer additional practical benefits. In this context, the current study investigated the potential of 1-MCP to accurately manipulate ripening of non-stored 'Hass' avocado fruit by treatment before or after ethylene and at different times during ripening. To investigate this, 500 nL L-1 1-MCP was applied within 1 day after harvest, followed by ethylene 0-14 days after 1-MCP. In addition, fruit were treated with ethylene, then 1-MCP 0-8 days after ethylene. Treatment of fruit with 500 nL L-1 1-MCP for 18 h at 20 degreesC provided the maximum effect by increasing the days from harvest to ripe (DTR) from 8 (with no 1-MCP) to 20. Fruit treated with 500 nL L-1 1-MCP for 18 h at 20 degreesC remained insensitive to 100 muL L-1 ethylene applied between 0 and 14 days after 1-MCP for 24 h at 20 degreesC. Ripening of fruit exposed to 100 muL L-1 ethylene for 24 h at 20 degreesC could be delayed by up to 3.3 days by applying 500 nL L-1 1-MCP for 18 h at 20 degreesC up to 2 days after ethylene treatment. However, once the fruit started to soften (sprung) there was little effect of 1-MCP on DTR, compared with no 1-MCP. 1-MCP treatment was associated with increased severity of body rots (caused mainly by Colletotrichum spp.) and stem-end rots (caused mainly by Dothiorella spp.), which was likely due to the increased DTR in these treatments. Significant differences in disease severity were found between orchards (replications), with replicates with low disease severity being less affected by 1-MCP treatment. These results indicate that 1-MCP can delay ripening, but careful sourcing of fruit is required to reduce the risk of diseases in ripe fruit. There is some capacity to delay ripening using 1-MCP after ethylene. There is little potential to control ripening using ethylene after treatment with 500 nL L-1 1-1-MCP, but lower concentrations may be more effective. (C) 2004 Elsevier B.V. All rights reserved.