MMP-9 and IL-1β as Targets for Diatoxanthin and Related Microalgal Pigments: Potential Chemopreventive and Photoprotective Agents

Photochemoprevention can be a valuable approach to counteract the damaging effects of environmental stressors (e.g., UV radiations) on the skin. Pigments are bioactive molecules, greatly attractive for biotechnological purposes, and with promising applications for human health. In this context, marine microalgae are a valuable alternative and eco-sustainable source of pigments that still need to be taken advantage of. In this study, a comparative in vitro photochemopreventive effects of twenty marine pigments on carcinogenic melanoma model cell B16F0 from UV-induced injury was setup. Pigment modulation of the intracellular reactive oxygen species (ROS) concentration and extracellular release of nitric oxide (NO) was investigated. At the cell signaling level, interleukin 1-β (IL-1β) and matrix metallopeptidase 9 protein (MMP-9) protein expression was examined. These processes are known to be involved in the signaling pathway, from UV stress to cancer induction. Diatoxanthin resulted the best performing pigment in lowering MMP-9 levels and was able to strongly lower IL-1β. This study highlights the pronounced bioactivity of the exclusively aquatic carotenoid diatoxanthin, among the others. It is suggested increasing research efforts on this molecule, emphasizing that a deeper integration of plant ecophysiological studies into a biotechnological context could improve the exploration and exploitation of bioactive natural products.     

Effect of pea canopy architecture on microclimate and consequences on ascochyta blight infection under field conditions

In order to investigate the impact of pea canopy architecture and development on microclimate and infection by Mycosphaerella pinodes, two field experiments were conducted in 2009 and 2010 at Le Rheu (France) to obtain canopies contrasted in height, closure dynamic, leaf area index (LAI) and leaf area density (LAD). Three pea cultivars (Athos, Antares, Gregor) were sown at two (80 and 40 seeds/m² in 2009) and three densities (80, 40 and 30 seeds/m² in 2010) and microclimatic sensors were located inside the canopy (at the bottom and in the middle) and outside. Two main sources of wetness were identified: rainfall and dew. During rainfall periods, average daily leaf wetness duration (LWD) was about 15 h, and 3 to 10 h longer inside than outside the canopies. LWD was positively correlated with LAI until canopy closure during these periods. During dry periods when dew was the only source of leaf wetness, average daily LWD was short, decreasing as the canopy developed. Shorter LWDs were observed at the base than at the mid-level of the canopies and longer LWDs were observed outside the canopy and inside the less dense canopies irrespective of the cultivar. LWD was negatively correlated with canopy height and LAI during these periods. Slow wind speeds were recorded inside the canopies (less than 0.5 km/h) and no significant canopy effect was observed on air temperature. An infection model was developed and showed that only rainfall periods which induced long LWDs inside the canopy, were favourable to M. pinodes infection under our climatic conditions and suggested a more favourable microclimate inside dense canopies.     

A Critical Assessment of the Quantification of Wheat Grain Arabinoxylans Using a Phloroglucinol Colorimetric Assay

Arabinoxylans (AX) of wheat (Triticum aestivum L.) play a critical role in processing, end‐use quality, and human health and nutrition. Consequently, an efficient, accurate method of AX quantification is desirable. The objective of this work was to evaluate a standard phloroglucinol colorimetric method for quantification of wheat AX. The method is based on the formation and spectrophotometric quantification of a phloroglucide product that results from the reaction of furfural produced during the condensation of pentose sugars with phloroglucinol. Method parameters, including reaction reagents and reaction times, were varied to identify areas for improved accuracy and consistency. Phloroglucide formation at three xylose concentrations was examined over time. The optimal reaction reagents and reaction times were determined based upon improved consistency in xylose quantification. The optimized method was used on xylose and arabinose standards and on whole meal wheat samples for total and water‐extractable AX content. Glucose was shown to be unnecessary in the reaction and was eliminated. A second‐order polynomial equation provided a slightly better fit to the nearly linear standard xylose curve. A reduced concentration of phloroglucinol of 10% was found to give equivalent results to the standard 20%. Optimum reaction time was 25 min, and it required the inclusion of all reagents. The phloroglucide product decreased in absorbance over time such that, within the range of xylose concentration examined, about 40–50% of the colored product was lost over 100 min; however, the rate of loss was linear over time. Four operators performed the optimized method on whole wheat meal samples for total and water‐extractable AX. Inter‐ and intraoperator variation was identified as an area requiring further study and improvement. However, all operators tended to rank the samples in a consistent manner. Compared with a gas chromatography–flame ionization detection method, the phloroglucinol method underestimated total AX by about 2.3% and water‐extractable AX by about 0.08%.     

Myelomeningocoele and a dermoid sinus-like lesion in a French bulldog

A 2-year-old male French bulldog was presented for investigation of lumbosacral pain and hindlimb ataxia associated with urinary and fecal incontinence. Survey radiography, myelography, and computed tomography images were suggestive of a dermoid sinus with associated spina bifida. Surgical intervention led to a resolution of pain and neurological deficits. Histopathological analysis of the excised tissue was compatible with a myelomeningocoele of the 7th lumbar vertebra.     

Investigation of volatiles in Charentais cantaloupe melons (Cucumis melo Var. cantalupensis). Characterization of aroma constituents in some cultivars

Volatile compounds of 15 Charentais melon cultivars, known to exhibit differences in their ripening behaviors and in their storage lives (wild, mid, and long shelf life), were investigated. Twenty-eight volatiles (11 esters, 8 sulfur compounds, 6 alcohols, and 3 carbonyl compounds) were isolated by direct dichloromethane extraction and analyzed by means of GC-MS and GC-FID. A considerable reduction in the aroma profile was observed for the long shelf life cultivars, in which total volatiles were 49-87% lower than in the wild or mid shelf life melons. Most of the esters such as ethyl 2-methylbutyrate, ethyl butyrate, ethyl hexanoate, hexyl acetate, and butyl acetate and sulfur compounds such as ethyl 2-(methylthio)acetate, 2-methylthioethanol, ethyl 3-(methylthio)propanoate, 3-(methylthio)propyl acetate, and 3-(methylthio)propanol with low odor values were 2-30-fold lower in long shelf life cultivars than in the others. Discrimination of long shelf life cultivars from wild and mid shelf life melons was achieved by statistical treatment of the data by principal component and variance analysis.     

Optimization of the analysis of flavor volatile compounds by liquid-liquid microextraction (LLME). Application to the aroma analysis of melons, peaches, grapes, strawberries, and tomatoes

A fast method based on liquid-liquid microextraction (LLME) has been developed for the analysis of volatile compounds in fruit and vegetable juices. The method was tested in an aqueous solution containing 49 common flavor compounds typically found in fruit aroma. Influence on extraction yield of the salts used, their levels, and the time of extraction was investigated. The efficiency of n-propyl gallate to inhibit the formation of secondary compounds from lipids during the crushing of fruit tissues was also tested. The proposed method was then applied to several authentic samples such as melons, peaches, grapes, strawberries, and tomatoes. The advantages and limitations of LLME are discussed.     

Modelling the efficacy of proposed mitigation areas for shorebirds: a case study on the Seine estuary, France

A behaviour-based model was used to explore the effect of an extension of the port at Le Havre (Port 2000), and the effect of proposed mitigation measures, on the mortality and body condition of the three main shorebird species that overwinter in the estuary of the river Seine, France. In the model, a 20% reduction in the area of mudflats on the north side of the estuary had little effect on curlew Numenius arquata mortality and body condition but significantly increased mortality and decreased body condition in dunlin Calidris alpina and oystercatchers Haematopus ostralegus. Disturbance of feeding birds both day and night had a significant effect on the mortality and body condition of all three shorebird species, as did disturbance of roosting birds. Disturbance of feeding birds in the daytime only had a significant effect on dunlin mortality and body condition, but not that of curlew and oystercatchers. In the model, the creation of a buffer zone to reduce disturbance of feeding birds restored shorebird mortality and body condition to pre-disturbance levels. A new mudflat area was also effective in mitigating the effect of habitat loss on all three shorebirds and in mitigating the effect of roost disturbance on dunlin and curlew. However, a new mudflat area was not effective in mitigating the effect of roost disturbance on oystercatcher mortality and body condition. The effectiveness of the mitigating mudflat depended as much on its size as its quality. We believe that this is the first time that anyone has been able to forecast the efficacy of proposed mitigation measures.     

Water-extractable and water-unextractable arabinoxylans affect gluten agglomeration behavior during wheat flour gluten-starch separation

Water-extractable arabinoxylan (WE-AX) of variable molecular weight (MW) and water-unextractable arabinoxylan (WU-AX) were added to wheat flour to study their effect on gluten agglomeration in a dough and batter gluten-starch separation process with recovery of gluten from the batter with a set of vibrating sieves (400, 250, and 125 microm). Low MW WE-AX had almost no impact on the distribution of the gluten on the different sieves. High MW WE-AX decreased yields of the largest (400 microm sieve) gluten aggregates, more than their medium MW counterparts, indicating the importance of AX MW for their effect on gluten interactions. Correlations between the total level of gluten protein recovered on the three sieves and the batter extract viscosity as well as between the proportion of gluten protein recovered on the 400 microm sieve to that on the three sieves and the batter extract viscosity pointed to the importance of viscosity as an indicator for gluten agglomeration, as did the fact that another viscosity increasing plant polysaccharide (guar gum) also negatively influenced gluten agglomeration. However, the obtained data cannot rule out that AX and guar gum also exert steric effects on gluten agglomeration. WU-AX, present as discrete cell wall fragments, had a negative impact on the level of large gluten aggregates. Taken together, the results show that both native WE-AX and WU-AX detrimentally impact gluten agglomeration.     

Recognition dynamics up to microseconds revealed from an RDC-derived ubiquitin ensemble in solution

Protein dynamics are essential for protein function, and yet it has been challenging to access the underlying atomic motions in solution on nanosecond-to-microsecond time scales. We present a structural ensemble of ubiquitin, refined against residual dipolar couplings (RDCs), comprising solution dynamics up to microseconds. The ensemble covers the complete structural heterogeneity observed in 46 ubiquitin crystal structures, most of which are complexes with other proteins. Conformational selection, rather than induced-fit motion, thus suffices to explain the molecular recognition dynamics of ubiquitin. Marked correlations are seen between the flexibility of the ensemble and contacts formed in ubiquitin complexes. A large part of the solution dynamics is concentrated in one concerted mode, which accounts for most of ubiquitin's molecular recognition heterogeneity and ensures a low entropic complex formation cost.     

A cellular microRNA mediates antiviral defense in human cells

In eukaryotes, 21- to 24-nucleotide-long RNAs engage in sequence-specific interactions that inhibit gene expression by RNA silencing. This process has regulatory roles involving microRNAs and, in plants and insects, it also forms the basis of a defense mechanism directed by small interfering RNAs that derive from replicative or integrated viral genomes. We show that a cellular microRNA effectively restricts the accumulation of the retrovirus primate foamy virus type 1 (PFV-1) in human cells. PFV-1 also encodes a protein, Tas, that suppresses microRNA-directed functions in mammalian cells and displays cross-kingdom antisilencing activities. Therefore, through fortuitous recognition of foreign nucleic acids, cellular microRNAs have direct antiviral effects in addition to their regulatory functions.