335 research outputs found
Integration of a Phosphatase Cascade with the MAP Kinase Pathway provides for a Novel Signal Processing Function
We mathematically modeled the receptor-activated MAP kinase signaling by
incorporating the regulation through cellular phosphatases. Activation induced
the alignment of a phosphatase cascade in parallel with the MAP kinase pathway.
A novel regulatory motif was thus generated, providing for the combinatorial
control of each MAPK intermediate. This ensured a non-linear mode of signal
transmission with the output being shaped by the balance between the strength
of input signal, and the activity gradient along the phosphatase axis. Shifts
in this balance yielded modulations in topology of the motif, thereby expanding
the repertoire of output responses. Thus we identify an added dimension to
signal processing, wherein the output response to an external stimulus is
additionally filtered through indicators that define the phenotypic status of
the cell.Comment: Whole Manuscript 33 pages inclduing Main text, 7 Figures and
Supporting Informatio
Implementation of GIS technologies for planning the valorisation of agricultural waste: the TANGO-Circular Project
The volume of waste produced by agricultural activities is constantly rising, due to the continuous increase of crop and livestock production, aimed to cover the nutritional needs of the accreting population of the Planet. According to recent estimations, the total amount of waste produced in the whole EU by the agricultural sector during the period 2010-2016, has been around 18.4 billion tons, which represents an average of 2.6 billion tons/year. This number is slightly exceeding the amount of waste from all other sectors combined. This enormous mass of waste has a significant environmental impact, which needs suitable solutions to reduce the carbon footprint of agriculture, while increasing the economic income for farmers.
A promising way to reduce agricultural waste, passes through the valorization of agricultural co-products, by-products and residues, as well as other non-organic materials - such as plastics, widely used in crop cultivation and animal production - after the end of their working life. In order to involve farmers to play an active role on this issue, contributing to transform what they currently consider as a “waste” into a new “resource”, under the perspective of a circular economy and for a more sustainable agriculture, the Project TANGO-Circular has been financed by the EU Erasmus+ Programme. Aim of this Project is to train farmers and other agricultural stakeholders to be involved in finding viable solutions to exploit unusable remains of
crops or animal farms, so as to enhance their financial input, while simultaneously contribute to reducing the environmental impact of their agro-livestock activities. With the aim to plan the valorization of agricultural waste, under the TANGO-Circular Project, a Geographical Information System (GIS) has been implemented through an open-access software (Q-GIS). This GIS has been structured into a first part dedicated to the quantification of agricultural waste flows – both organic, coming from agroindustrial activities, and not-organic, such as plastics - and a second part, focused on the spatial distribution of these flows in the study area of the project partners. Through GIS, the areas with high density of agricultural waste have been pointed out, and the suitable location of potential collection centres has been proposed. The maps that have been produced, as well as the GIS database, are always updatable tools, useful also for monitoring and optimizing the sorting and collection of agricultural waste from the farms, their suitable treatments and transport to the collection centers or recycling stations. The implemented GIS methodology has revealed very useful to support farmers and their associations, as well as all public bodies interested to govern the agricultural waste flows, to individuate possible solutions designed for the valorization of these flows, in the perspective of a circular economy. The sustainability and economic, territorial, environmental and social convenience of each form of valorization designed have been investigated, and criticalities associated with each phase of the process and consequent implementation of appropriate solutions to each problem have been addressed. Finally, further possible solutions, aimed at an increasingly better valorization of these flows, have been proposed as well
ERK2 Suppresses Self-Renewal Capacity of Embryonic Stem Cells, but Is Not Required for Multi-Lineage Commitment
Activation of the FGF-ERK pathway is necessary for naïve mouse embryonic stem (ES) cells to exit self-renewal and commit to early differentiated lineages. Here we show that genetic ablation of Erk2, the predominant ERK isozyme expressed in ES cells, results in hyper-phosphorylation of ERK1, but an overall decrease in total ERK activity as judged by substrate phosphorylation and immediate-early gene (IEG) induction. Normal induction of this subset of canonical ERK targets, as well as p90RSK phosphorylation, was rescued by transgenic expression of either ERK1 or ERK2 indicating a degree of functional redundancy. In contrast to previously published work, Erk2-null ES cells exhibited no detectable defect in lineage specification to any of the three germ layers when induced to differentiate in either embryoid bodies or in defined neural induction conditions. However, under self-renewing conditions Erk2-null ES cells express increased levels of the pluripotency-associated transcripts, Nanog and Tbx3, a decrease in Nanog-GFP heterogeneity, and exhibit enhanced self-renewal in colony forming assays. Transgenic add-back of ERK2 is capable of restoring normal pluripotent gene expression and self-renewal capacity. We show that ERK2 contributes to the destabilization of ES cell self-renewal by reducing expression of pluripotency genes, such as Nanog, but is not specifically required for the early stages of germ layer specification
A Quantitative Image Cytometry Technique for Time Series or Population Analyses of Signaling Networks
Background: Modeling of cellular functions on the basis of experimental observation is increasingly common in the field of cellular signaling. However, such modeling requires a large amount of quantitative data of signaling events with high spatio-temporal resolution. A novel technique which allows us to obtain such data is needed for systems biology of cellular signaling. Methodology/Principal Findings: We developed a fully automatable assay technique, termed quantitative image cytometry (QIC), which integrates a quantitative immunostaining technique and a high precision image-processing algorithm for cell identification. With the aid of an automated sample preparation system, this device can quantify protein expression, phosphorylation and localization with subcellular resolution at one-minute intervals. The signaling activities quantified by the assay system showed good correlation with, as well as comparable reproducibility to, western blot analysis. Taking advantage of the high spatio-temporal resolution, we investigated the signaling dynamics of the ERK pathway in PC12 cells. Conclusions/Significance: The QIC technique appears as a highly quantitative and versatile technique, which can be a convenient replacement for the most conventional techniques including western blot, flow cytometry and live cell imaging
Regulation of atypical MAP kinases ERK3 and ERK4 by the phosphatase DUSP2
The atypical MAP kinases ERK3 and ERK4 are activated by phosphorylation of a serine residue lying within the activation loop signature sequence S-E-G. However, the regulation of ERK3 and ERK4 phosphorylation and activity is poorly understood. Here we report that the inducible nuclear dual-specificity MAP kinase phosphatase (MKP) DUSP2, a known regulator of the ERK and p38 MAPKs, is unique amongst the MKP family in being able to bind to both ERK3 and ERK4. This interaction is mediated by a conserved common docking (CD) domain within the carboxyl-terminal domains of ERK3 and ERK4 and the conserved kinase interaction motif (KIM) located within the non-catalytic amino terminus of DUSP2. This interaction is direct and results in the dephosphorylation of ERK3 and ERK4 and the stabilization of DUSP2. In the case of ERK4 its ability to stabilize DUSP2 requires its kinase activity. Finally, we demonstrate that expression of DUSP2 inhibits ERK3 and ERK4-mediated activation of its downstream substrate MK5. We conclude that the activity of DUSP2 is not restricted to the classical MAPK pathways and that DUSP2 can also regulate the atypical ERK3/4-MK5 signalling pathway in mammalian cells
Decreased expression of dual-specificity phosphatase 9 is associated with poor prognosis in clear cell renal cell carcinoma
Background: The molecular mechanisms involved in the development and progression of clear cell renal cell carcinomas (ccRCCs) are poorly understood. The objective of this study was to analyze the expression of dual-specificity phosphatase 9 (DUSP-9) and determine its clinical significance in human ccRCCs. Methods: The expression of DUSP-9 mRNA was determined in 46 paired samples of ccRCCs and adjacent normal tissues by using real-time qPCR. The expression of the DUSP-9 was determined in 211 samples of ccRCCs and 107 paired samples of adjacent normal tissues by immunohistochemical analysis. Statistical analysis was performed to define the relationship between the expression of DUSP-9 and the clinical features of ccRCC. Results: The mRNA level of DUSP-9, which was determined by real-time RT-PCR, was found to be significantly lower in tumorous tissues than in the adjacent non-tumorous tissues (p < 0.001). An immunohistochemical analysis of 107 paired tissue specimens showed that the DUSP-9 expression was lower in tumorous tissues than in the adjacent non-tumorous tissues (p < 0.001). Moreover, there was a significant correlation between the DUSP-9 expression in ccRCCs and gender (p = 0.031), tumor size (p = 0.001), pathologic stage (p = 0.001), Fuhrman grade (p = 0.002), T stage (p = 0.001), N classification (p = 0.012), metastasis (p = 0.005), and recurrence (p < 0.001). Patients with lower DUSP-9 expression had shorter overall survival time than those with higher DUSP-9 expression (p < 0.001). Multivariate analysis indicated that low expression of the DUSP-9 was an independent predictor for poor survival of ccRCC patients. Conclusion: To our knowledge, this is the first study that determines the relationship between DUSP-9 expression and prognosis in ccRCC. We found that decreased expression of DUSP-9 is associated with poor prognosis in ccRCC. DUSP-9 may represent a novel and useful prognostic marker for ccRCC
The Inhibitory Effect of Salmon Calcitonin on Tri-Iodothyronine Induction of Early Hypertrophy in Articular Cartilage
Salmon calcitonin has chondroprotective effect both in vitro and in vivo, and is therefore being tested as a candidate drug for cartilage degenerative diseases. Recent studies have indicated that different chondrocyte phenotypes may express the calcitonin receptor (CTR) differentially. We tested for the presence of the CTR in chondrocytes from tri-iodothyronin (T3)-induced bovine articular cartilage explants. Moreover, investigated the effects of human and salmon calcitonin on the explants.Early chondrocyte hypertrophy was induced in bovine articular cartilage explants by stimulation over four days with 20 ng/mL T3. The degree of hypertrophy was investigated by molecular markers of hypertrophy (ALP, IHH, COLX and MMP13), by biochemical markers of cartilage turnover (C2M, P2NP and AGNxII) and histology. The expression of the CTR was detected by qPCR and immunohistochemistry. T3-induced explants were treated with salmon or human calcitonin. Calcitonin down-stream signaling was measured by levels of cAMP, and by the molecular markers.Compared with untreated control explants, T3 induction increased expression of the hypertrophic markers (p<0.05), of cartilage turnover (p<0.05), and of CTR (p<0.01). Salmon, but not human, calcitonin induced cAMP release (p<0.001). Salmon calcitonin also inhibited expression of markers of hypertrophy and cartilage turnover (p<0.05).T3 induced early hypertrophy of chondrocytes, which showed an elevated expression of the CTR and was thus a target for salmon calcitonin. Molecular marker levels indicated salmon, but not human, calcitonin protected the cartilage from hypertrophy. These results confirm that salmon calcitonin is able to modulate the CTR and thus have chondroprotective effects
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