Magnetic resonance imaging characterization of different experimental autoimmune encephalomyelitis models and the therapeutic effect of glatiramer acetate

The roles of inflammation and degeneration as well as of gray matter abnormalities in multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE) are controversial. We analyzed the pathological manifestations in two EAE models, the chronic oligodendrocyte glycoprotein (MOG)-induced versus the relapsing–remitting proteolipid protein (PLP)-induced, along the disease progression, using advanced magnetic resonance imaging (MRI) parameters. The emphasis of this study was the overall assessment of the whole brain by histogram analysis, as well as the detection of specific affected regions by voxel based analysis (VBA) using quantitative T2, magnetization transfer ratio (MTR) and diffusion tensor imaging (DTI). Brains of EAE-inflicted mice from both models revealed multiple white and gray matter areas with significant changes from naïve mice for all MRI parameters. Ventricle swelling was more characteristic to the PLP-induced model. Decreased MTR values and increased apparent diffusion coefficient (ADC) were observed mainly in MOG-induced EAE, indicative of macromolecular loss and structural CNS damage involvement in the chronic disease. The MS drug glatiramer acetate (GA), applied either as prevention or therapeutic treatment, affected all the MRI pathological manifestations, resulting in reduced T2 values and ventricle volume, elevated MTR and decreased ADC, in comparison to untreated EAE-inflicted mice. In accord, immunohistochemical analysis indicated less histological damage and higher amount of proliferating oligodendrocyte progenitor cells after GA treatment. The higher brain tissue integrity reflected by the MRI parameters on the level of the whole brain and in specific regions supports the in situ anti-inflammatory and neuroprotective consequences of GA treatment

Detection of Crop Diseases Using Enhanced Variability Imagery Data and Convolutional Neural Networks

The timely detection of crop diseases is critical for securing crop productivity, lowering production costs, and minimizing agrochemical use. This study presents a crop disease identification method that is based on Convolutional Neural Networks (CNN) trained on images taken with consumer-grade cameras. Specifically, this study addresses the early detection of wheat yellow rust, stem rust, powdery mildew, potato late blight, and wild barley net blotch. To facilitate this, pictures were taken in situ without modifying the scene, the background, or controlling the illumination. Each image was then split into several patches, thus retaining the original spatial resolution of the image while allowing for data variability. The resulting dataset was highly diverse since the disease manifestation, imaging geometry, and illumination varied from patch to patch. This diverse dataset was used to train various CNN architectures to find the best match. The resulting classification accuracy was 95.4 ± 0.4%. These promising results lay the groundwork for autonomous early detection of plant diseases. Guidelines for implementing this approach in realistic conditions are also discussed

A benchmark dataset for automatic detection of claims and evidence in the context of controversial topics

Abstract We describe a novel and unique argumentative structure dataset. This corpus consists of data extracted from hundreds of Wikipedia articles using a meticulously monitored manual annotation process. The result is 2,683 argument elements, collected in the context of 33 controversial topics, organized under a simple claim-evidence structure. The obtained data are publicly available for academic research

The Arabidopsis DESPERADO/AtWBC11 Transporter Is Required for Cutin and Wax Secretion1[C][W]

The cuticle fulfills multiple roles in the plant life cycle, including protection from environmental stresses and the regulation of organ fusion. It is largely composed of cutin, which consists of C16-18 fatty acids. While cutin composition and biosynthesis have been studied, the export of cutin monomers out of the epidermis has remained elusive. Here, we show that DESPERADO (AtWBC11) (abbreviated DSO), encoding a plasma membrane-localized ATP-binding cassette transporter, is required for cutin transport to the extracellular matrix. The dso mutant exhibits an array of surface defects suggesting an abnormally functioning cuticle. This was accompanied by dramatic alterations in the levels of cutin monomers. Moreover, electron microscopy revealed unusual lipidic cytoplasmatic inclusions in epidermal cells, disappearance of the cuticle in postgenital fusion areas, and altered morphology of trichomes and pavement cells. We also found that DSO is induced by salt, abscisic acid, and wounding stresses and its loss of function results in plants that are highly susceptible to salt and display reduced root branching. Thus, DSO is not only essential for developmental plasticity but also plays a vital role in stress responses

AUXIN RESPONSE FACTOR 2 Intersects Hormonal Signals in the Regulation of Tomato Fruit Ripening.

The involvement of ethylene in fruit ripening is well documented, though knowledge regarding the crosstalk between ethylene and other hormones in ripening is lacking. We discovered that AUXIN RESPONSE FACTOR 2A (ARF2A), a recognized auxin signaling component, functions in the control of ripening. ARF2A expression is ripening regulated and reduced in the rin, nor and nr ripening mutants. It is also responsive to exogenous application of ethylene, auxin and abscisic acid (ABA). Over-expressing ARF2A in tomato resulted in blotchy ripening in which certain fruit regions turn red and possess accelerated ripening. ARF2A over-expressing fruit displayed early ethylene emission and ethylene signaling inhibition delayed their ripening phenotype, suggesting ethylene dependency. Both green and red fruit regions showed the induction of ethylene signaling components and master regulators of ripening. Comprehensive hormone profiling revealed that altered ARF2A expression in fruit significantly modified abscisates, cytokinins and salicylic acid while gibberellic acid and auxin metabolites were unaffected. Silencing of ARF2A further validated these observations as reducing ARF2A expression let to retarded fruit ripening, parthenocarpy and a disturbed hormonal profile. Finally, we show that ARF2A both homodimerizes and interacts with the ABA STRESS RIPENING (ASR1) protein, suggesting that ASR1 might be linking ABA and ethylene-dependent ripening. These results revealed that ARF2A interconnects signals of ethylene and additional hormones to co-ordinate the capacity of fruit tissue to initiate the complex ripening process

Efficient targeted degradation via reversible and irreversible covalent PROTACs

PROteolysis Targeting Chimeras (PROTACs) represent an exciting inhibitory modality with many advantages, including sub-stoichiometric degradation of targets. Their scope, though, is still limited to-date by the requirement for a sufficiently potent target binder. A solution that proved useful in tackling challenging targets is the use of electrophiles to allow irreversible binding to the target. However, such binding will negate the catalytic nature of PROTACs. Reversible covalent PROTACs potentially offer the best of both worlds. They possess the potency and selectivity associated with the formation of the covalent bond, while being able to dissociate and regenerate once the protein target is degraded. Using Bruton’s tyrosine kinase (BTK) as a clinically relevant model system, we show efficient covalent degradation by non-covalent, irreversible covalent and reversible covalent PROTACs, with 85% degradation. Our data suggests that part of the degradation by our irreversible covalent PROTACs is driven by reversible binding prior to covalent bond formation, while the reversible covalent PROTACs drive degradation primarily by covalent engagement. The PROTACs showed enhanced inhibition of B cell activation compared to Ibrutinib, and exhibit potent degradation of BTK in patients-derived primary chronic lymphocytic leukemia cells. The most potent reversible covalent PROTAC, RC-3, exhibited enhanced selectivity towards BTK compared to non-covalent and irreversible covalent PROTACs. These compounds may pave the way for the design of covalent PROTACs for a wide variety of challenging targets.</p

Dimerization of the ARF2A protein and its interaction.

<p>ARF2A was cloned downstream of the DNA-binding domain (DB-ARF2A) and co-transformed into yeast with either (A) ARF2A cloned downstream of the activation domain (AD-ARF2A); or (B) ASR1 cloned downstream of the activation domain (AD-ASR1), yeast growth on media lacking leucine, tryptophan, histidine and adenine indicated positive protein-protein interactions. (C) Relative expression levels of <i>ASR1</i> in WT cv. MicroTom fruit at five developmental stages (IG: immature green; MG: mature green; Br: breaker; Or: orange; and R: red), error bars represent SE; statistical significance was evaluated using an ANOVA test (JMP software, SAS) with three biological repeats based on the average of three technical replicates, values indicated by the same letter (a,b,c) are not statistically significant, p-value<0.05. (D) A Bimolecular Fluorescence Complementation assay (BiFC) was carried out by transient expression in tobacco leaves; ARF2A was cloned downstream of the amino-terminal region of YFP (yellow fluorescent protein; YN-ARF2A) and ASR1 was cloned downstream of the carboxy-terminal region of YFP (YC-ASR1); leaf regions were examined for fluorescent signal by light and confocal fluorescence microscopy. Inset zoom region shows that the ARF2A-ASR1 interaction is nuclear localized. Scale bars in the light and confocal fluorescence microscopy represent 50 μm and 10 μm, respectively.</p

Plant cholesterol biosynthetic pathway overlaps with phytosterol metabolism

The amount of cholesterol made by many plants is not negligible. Whereas cholesterogenesis in animals was elucidated decades ago, the plant pathway has remained enigmatic. Among other roles, cholesterol is a key precursor for thousands of bioactive plant metabolites, including the well-known Solanum steroidal glycoalkaloids. Integrating tomato transcript and protein co-expression data revealed candidate genes putatively associated with cholesterol biosynthesis. A combination of functional assays including gene silencing, examination of recombinant enzyme activity and yeast mutant complementation suggests the cholesterol pathway comprises 12 enzymes acting in 10 steps. It appears that half of the cholesterogenesis-specific enzymes evolved through gene duplication and divergence from phytosterol biosynthetic enzymes, whereas others act reciprocally in both cholesterol and phytosterol metabolism. Our findings provide a unique example of nature's capacity to exploit existing protein folds and catalytic machineries from primary metabolism to assemble a new, multi-step metabolic pathway. Finally, the engineering of a 'high-cholesterol' model plant underscores the future value of our gene toolbox to produce high-value steroidal compounds via synthetic biology