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111.
Distribution of diamine oxidase activity and polyamine pattern in bean and soybean seedlings at different stages of germination 总被引:3,自引:0,他引:3
Diamine oxidase (DAO, EC 1.4.3.6.) activity and polyamine content were measured in the shoot apex, leaves, epicotyl, cotyledons, hypocotyl and roots of light-grown bean ( Phaseolus vulgaris L. cv. Lingot) and soybean ( Glycine max L. cv. Sakai) seedlings at 3 different stages of germination (5, 8 and 14 days) as well as in embryos and cotyledons from soaked seeds. No DAO activity was detected in embryos and cotyledons of either plants. In bean seedlings DAO activity was only detectable in the shoot apex, primary leaves and cotyledons, while in soybean the activity was only detectable in the hypocotyl and roots. During seedling growth, in both plants, a different pattern of DAO activity was observed. In both species spermidine and spermine were the most abundant polyamines in embryos and cotyledons. Cadaverine, absent in bean, was only detected in soybean embryos. In the seedlings of both plants, increasing gradients of putrescine, spermidine and spermine from base to shoot apex were found. A high concentration of cadaverine was present in soybean hypocotyls and roots. A possible correlation between DAO activity and the endogenous content of the preferential substrate is discussed in relation to the possible involvement of the enzyme in regulating the cellular level of polyamines. 相似文献
112.
Maila Giannandrea Maria Lidia Mignogna Salvatore Carrabino Matteo Vecellio Silvia Russo Lidia Larizza Hans-Hilger Ropers Vera Kalscheuer Cindy Skinner Jozef Gecz Hilde Van Esch Jamel Chelly Daniela Toniolo Patrizia D'Adamo 《American journal of human genetics》2010,86(2):185-195
Human Mental Retardation (MR) is a common and highly heterogeneous pediatric disorder affecting around 3% of the general population; at least 215 X-linked MR (XLMR) conditions have been described, and mutations have been identified in 83 different genes, encoding proteins with a variety of function, such as chromatin remodeling, synaptic function, and intracellular trafficking. The small GTPases of the RAB family, which play an essential role in intracellular vesicular trafficking, have been shown to be involved in MR. We report here the identification of mutations in the small GTPase RAB39B gene in two male patients. One mutation in family X (D-23) introduced a stop codon seven amino acids after the start codon (c.21C > A; p.Y7X). A second mutation, in the MRX72 family, altered the 5′ splice site (c.215+1G > A) and normal splicing. Neither instance produced a protein. Mutations segregate with the disease in the families, and in some family members intellectual disabilities were associated with autism spectrum disorder, epileptic seizures, and macrocephaly. We show that RAB39B, a novel RAB GTPase of unknown function, is a neuronal-specific protein that is localized to the Golgi compartment. Its downregulation leads to an alteration in the number and morphology of neurite growth cones and a significant reduction in presynaptic buttons, suggesting that RAB39B is required for synapse formation and maintenance. Our results demonstrate developmental and functional neuronal alteration as a consequence of downregulation of RAB39B and emphasize the critical role of vesicular trafficking in the development of neurons and human intellectual abilities. 相似文献
113.
A. M. Berghella Patrizia Pellegrini Tiziana Del Beato Matteo Marini Ennio Tomei Domenico Adorno Carlo Umberto Casciani 《Cancer immunology, immunotherapy : CII》1997,45(5):241-249
Current research has still not clarified the biological role of soluble interleukin(IL)-2 receptor (sIL-2R) and the significance
of its increase in the serum of colon cancer patients compared to healthy subjects. To address these questions at the immunological
level in a group of patients and healthy subjects, we determined the sIL-2R level in the serum and its release from peripheral
blood mononuclear cells (PBMC) as a function of tumour necrosis factor (TNF) α, IL-1α, IL-1β, IL-2, interferon (IFN) γ, IL-4,
IL-6 and IL-10 levels in the serum and PBMC production; and PBMC proliferative responses to IL-2, IL-4 and anti-CD3 monoclonal
antibody (CD3), variously combined. The level of sIL-2R in patients’ serum was higher than in healthy subjects and correlated
with the stage of advancement. Moreover, while in healthy subjects the serum level of sIL-2R was not significantly correlated
with other parameters, in patients it was positively related to IL-4, IL-6 and IL-10 serum levels, PBMC IL-4 production and
to the PBMC proliferative response to CD3 and CD3+IL-2; it was negatively correlated to IL-2 serum level and IL-1β PBMC release.
A negative connection between IFNγ serum level and the PBMC production of sIL-2R was also found. This suggests that the increase
of sIL-2R in the serum of patients, compared to healthy subjects, is involved in the inappropriate expansion of the T helper
(TH2) suppressive immune response, which we previously reported. The multivariate statistical method supported the above suggestions
and we also found that, in healthy subjects, the up- and down-regulation of sIL-2R in the serum within the physiological ranges
seems to have a regulating role in the relationships between TNFα, IFNγ and IL-4, IL-6, contributing to the operation of the
cytokine network between TH1 and TH2 cells. However, in patients compared to healthy subjects the increased sIL-2R serum level
seems to direct the immune response towards a suppressive type, which may be due to an alteration in the above-mentioned physiological
regulating role.
Received: 12 April 1997 / Accepted: 4 September 1997 相似文献
114.
Lactoferrin (Lf) is a mammalian exclusive protein widely distributed in milk and exocrine secretions exhibiting multifunctional
properties. Many of the proven or proposed functions of Lf, apart from its iron binding activity, depend on its capacity to
bind to other macromolecules. Lf can bind and sequester lipopolysaccharide (LPS), thus preventing pro-inflammatory pathway
activation, sepsis and tissue damage. However, the interplay between Lf and LPS is complex, and may result in different outcomes,
including both suppression of the inflammatory response and immune activation. These findings are critically relevant in the
development of Lf-based therapeutic interventions in humans. Understanding the molecular basis and functional consequences
of Lf-LPS interaction will provide insights for determining its role in health and disease. 相似文献
115.
Giuseppe Falini Giorgio Sartor Daniele Fabbri Patrizia Vergni Simona Fermani Angela M. Belcher Galen D. Stucky Daniel E. Morse 《Journal of structural biology》2011,173(1):128-137
The interstitial green sheets in abalone shell nacre are shown to be bifacially differentiated trilaminate polymeric complexes, with glycoprotein layers sandwiching a central core containing chitin. They share some common feature with the organic matrix layers between the aragonite tablets in the nacre and the periostracum, and show similarities to the myostracum. Thus, although the green sheet is reported to be unique to the abalone shell, it represents an interesting model for the study of molluscan shell biomineralization processes. Indeed, during shell formation, prismatic and spherulitic aragonite precedes and follows the deposition of the interstitial green polymeric composite sheets, and there is evidence to suggest that these sheets demark the interruption of nacre synthesis and serve to nucleate the resumption of calcium carbonate crystal growth. The green polymeric interstitial sheet purified from the abalone shell was investigated by spectroscopic and imaging techniques: FTIR, confocal microscopy, scanning and transmission electron microscopy, and by pyrolysis combined with GC–MS. Structural and compositional differences are observed between the surfaces of the two sides of the interstitial polymeric composite sheets. Moreover, comparative crystallization experiments on the green sheet sides also reveal asymmetry with respect to the nucleation of calcium carbonate. These findings suggest that these bifacially differentiated interstitial composites may play an active role in the mineral assembly processes, with one of the surfaces acting as a crystal nucleator. 相似文献
116.
Michael Dewaele Wim Martinet Noemí Rubio Tom Verfaillie Peter A. de Witte Jacques Piette Patrizia Agostinis 《Journal of cellular and molecular medicine》2011,15(6):1402-1414
Reactive oxygen species (ROS) concurrently instigate apoptosis and autophagy pathways, but the link between these processes remains unclear. Because cytotoxic ROS formation is exploited in anticancer therapy, such as in photodynamic therapy (PDT), a better understanding of the complex interplay between autophagy and apoptosis is urgently required. Previously, we reported that ROS generated by PDT with an endoplasmic reticulum (ER)-associated sensitizer leads to loss of ER-Ca2+ homeostasis, ER stress and apoptosis. Here we show that PDT prompted Akt-mTOR (mammalian target of rapamycin) pathway down-regulation and stimulated macroautophagy (MA) in cancer and normal cells. Overexpression of the antioxidant enzyme glutathione peroxidase-4 reversed mTOR down-regulation and blocked MA progression and apoptosis. Attenuating MA using Atg5 knockdown or 3-methyladenine, reduced clearance of oxidatively damaged proteins and increased apoptosis, thus revealing a cytoprotective role of MA in PDT. Paradoxically, genetic loss of MA improved clearance of oxidized proteins and reduced photokilling. We found that up-regulation of chaperone-mediated autophagy (CMA) in unstressed Atg5−/− cells compensated for MA loss and increased cellular resistance to PDT. CMA-deficient cells were significantly sensitized to photokilling but were protected against the ER stressor thapsigargin. These results disclose a stress-specific recruitment of autophagy pathways with cytoprotective function and unravel CMA as the dominant defence mechanism against PDT. 相似文献
117.
Ángel G. Polanco Rodríguez M. Inmaculada Riba López T. Ángel DelValls Casillas Patrizia Quattrocchi Fernando J. Álvarez Cervera Francisco J. Solorio Sánchez 《人类与生态风险评估》2015,21(7):1960-1979
In order to analyze risk perception related to the use and handling of organochlorine pesticides (OCP) in agricultural and livestock activities among Maya communities of Yucatan, Mexico, and to study their impact on public health and the environment, we conducted an analytical study applying 274 semi-structured interviews in 11 municipalities in the zone called “Ring of Cenotes.” The harmful effects of agrochemicals on water supplies, soils, air, and human health were considered, including the indoor use of pesticides to preserve harvest products. Recent studies showed high levels of OCP in groundwater. A generalized low risk perception related to human health and the environment due to pesticide use was found. Likewise, social parameters were analyzed, including the educational level, as well as risk factors related to groundwater karst vulnerability. Pesticides that have been banned by international conventions are still in use. The occurrence of some diseases such as cervical cancer, with a very high prevalence at the national level, and the practice of obtaining drinking water from polluted wells and sinkholes, may be associated with this low risk perception and with poor social conditions. Establishing programs on health education, agro-ecological production alternatives, and water chemical quality monitoring is recommended. 相似文献
118.
Part of Ran is associated with AKAP450 at the centrosome: involvement in microtubule-organizing activity 总被引:9,自引:0,他引:9 下载免费PDF全文
Keryer G Di Fiore B Celati C Lechtreck KF Mogensen M Delouvee A Lavia P Bornens M Tassin AM 《Molecular biology of the cell》2003,14(10):4260-4271
The small Ran GTPase, a key regulator of nucleocytoplasmic transport, is also involved in microtubule assembly and nuclear membrane formation. Herein, we show by immunofluorescence, immunoelectron microscopy, and biochemical analysis that a fraction of Ran is tightly associated with the centrosome throughout the cell cycle. Ran interaction with the centrosome is mediated by the centrosomal matrix A kinase anchoring protein (AKAP450). Accordingly, when AKAP450 is delocalized from the centrosome, Ran is also delocalized, and as a consequence, microtubule regrowth or anchoring is altered, despite the persisting association of gamma-tubulin with the centrosome. Moreover, Ran is recruited to Xenopus sperm centrosome during its activation for microtubule nucleation. We also demonstrate that centrosomal proteins such as centrin and pericentrin, but not gamma-tubulin, AKAP450, or ninein, undertake a nucleocytoplasmic exchange as they concentrate in the nucleus upon export inhibition by leptomycin B. Together, these results suggest a challenging possibility, namely, that centrosome activity could depend upon nucleocytoplasmic exchange of centrosomal proteins and local Ran-dependent concentration at the centrosome. 相似文献
119.
Background
The semaphorins and their receptors, the plexins, are proteins related to c-Met and the scatter factors that have been implicated in an expanding signal transduction network involving co-receptors, RhoA and Ras activation and deactivation, and phosphorylation events. Our previous work has demonstrated that Semaphorin 4D (Sema4D) acts through its receptor, Plexin-B1, on endothelial cells to promote angiogenesis in a RhoA and Akt-dependent manner. Since NF-κB has been linked to promotion of angiogenesis and can be activated by Akt in some contexts, we wanted to examine NF-κB in Sema4D treated cells to determine if there was biological significance for the pro-angiogenic phenotype observed in endothelium.Methods/Principal Findings
Using RNA interference techniques, gel shifts and NF-κB reporter assays, we demonstrated NF-κB translocation to the nucleus in Sema4D treated endothelial cells occurring downstream of Plexin-B1. This response was necessary for endothelial cell migration and capillary tube formation and protected endothelial cells against apoptosis as well, but had no effect on cell proliferation. We dissected Plexin-B1 signaling with chimeric receptor constructs and discovered that the ability to activate NF-κB was dependent upon Plexin-B1 acting through Rho and Akt, but did not involve its role as a Ras inhibitor. Indeed, inhibition of Rho by C3 toxin and Akt by blocked Sema4D-mediated endothelial cell migration and tubulogenesis. We also observed that Sema4D treatment of endothelial cells induced production of the NF-κB downstream target IL-8, a response necessary for angiogenesis. Finally, we could show through co-immunofluorescence for p65 and CD31 that Sema4D produced by tumor xenografts in nude mice activated NF-κB in vessels of the tumor stroma. LY294002Conclusion/Significance
These findings provide evidence that Sema4D/Plexin-B1-mediated NF-κB activation and IL-8 production is critical in the generation a pro-angiogenic phenotype in endothelial cells and suggests a new therapeutic target for the anti-angiogenic treatment of some cancers. 相似文献120.
Mencarelli A Distrutti E Renga B D'Amore C Cipriani S Palladino G Donini A Ricci P Fiorucci S 《PloS one》2011,6(7):e22978