A novel bioactive peptide from yoghurts modulates expression of the gel-forming MUC2 mucin as well as population of goblet cells and Paneth cells along the small intestine

Several studies demonstrated that fermented milks may provide a large number of bioactive peptides into the gastrointestinal tract. We previously showed that beta-casomorphin-7, an opioid-like peptide produced from bovine β-casein, strongly stimulates intestinal mucin production in ex vivo and in vitro models, suggesting the potential benefit of milk bioactive peptides on intestinal protection. In the present study, we tested the hypothesis that the total peptide pool (TPP) from a fermented milk (yoghurt) may act on human intestinal mucus-producing cells (HT29-MTX) to induce mucin expression. Our aim was then to identify the peptide(s) carrying the biological activity and to study its impact in vivo on factors involved in gut protection after oral administration to rat pups (once a day, 9 consecutive days). TPP stimulated MUC2 and MUC4 gene expression as well as mucin secretion in HT29-MTX cells. Among the four peptide fractions that were separated by preparative reversed-phase high-performance liquid chromatography, only the C2 fraction was able to mimic the in vitro effect of TPP. Interestingly, the sequence [94-123] of β-casein, present only in C2 fraction, also regulated mucin production in HT29-MTX cells. Oral administration of this peptide to rat pups enhanced the number of goblet cells and Paneth cells along the small intestine. These effects were associated with a higher expression of intestinal mucins (Muc2 and Muc4) and of antibacterial factors (lysozyme, rdefa5). We conclude that the peptide β-CN(94-123) present in yoghurts may maintain or restore intestinal homeostasis and could play an important role in protection against damaging agents of the intestinal lumen.     

Genotypic variation in source and sink traits affects the response of photosynthesis and growth to elevated atmospheric CO2

This study aimed to understand the response of photosynthesis and growth to e-CO₂ conditions (800 vs. 400 μmol mol⁻¹) of rice genotypes differing in source–sink relationships. A proxy trait called local C source–sink ratio was defined as the ratio of flag leaf area to the number of spikelets on the corresponding panicle, and five genotypes differing in this ratio were grown in a controlled greenhouse. Differential CO₂ resources were applied either during the 2 weeks following heading (EXP1) or during the whole growth cycle (EXP2). Under e-CO₂, low source–sink ratio cultivars (LSS) had greater gains in photosynthesis, and they accumulated less nonstructural carbohydrate in the flag leaf than high source–sink ratio cultivars (HSS). In EXP2, grain yield and biomass gain was also greater in LSS probably caused by their strong sink. Photosynthetic capacity response to e-CO₂ was negatively correlated across genotypes with local C source–sink ratio, a trait highly conserved across environments. HSS were sink-limited under e-CO₂, probably associated with low triose phosphate utilization (TPU) capacity. We suggest that the local C source–sink ratio is a potential target for selecting more CO₂-responsive cultivars, pending validation for a broader genotypic spectrum and for field conditions.     

Plasmolipin—a new player in endocytosis and epithelial development

Polarized vesicle sorting is essential not only for epithelial cell function but also for cell polarization and tissue morphogenesis. Endocytosis is a key determinant of the surface abundance of plasma membrane proteins and is highly regulated. In an important recent paper, Rodríguez‐Fraticelli et al ( 2015 ) identify a new player in apical endocytosis—a previously uncharacterized protein called Plasmolipin. They report not only its mechanism of action through binding to an epsin, but also highlight an essential role in regulating Notch signaling, which controls epithelial differentiation.     

An evaluation of different methods for assessing eggshell pigmentation and pigment concentration using great tit eggs

The striking variation in colour and maculation of bird eggs has fascinated biologists since centuries, and many hypotheses based on mechanical, physiological or signalling functions have been proposed for its evolution by natural and sexual selection. Protoporphyrin is the main eggshell pigment found in brown maculated eggs, and is assumed to function as a mediator of these selection processes. It is a precursor of heme with pro‐oxidant properties, and hence a link between brown maculation and female condition has been proposed and tested in a number of studies, albeit with contrasting results. A variety of different visual methods have been used to quantify outer eggshell pigmentation, which has been assumed to correspond to overall quantity of protoporphyrin in the shell. Yet, this relationship has rarely been tested. The aim of this study was to apply four commonly used methods to assess pigmentation in great tit eggs with protoporphyrin as the predominant eggshell pigment, and to compare the results of these methods. Specifically, we 1) ranked eggshell pigmentation by human naked eye, 2) applied a granularity approach and 3) measured spectrophotometric reflectance of eggshell pigments. Second, we estimated the relationship between outer eggshell pigmentation (i.e. estimated by three different methods above) and true protoporphyrin concentration deposited in the entire shell measured by HPLC. Among‐method estimates were significantly correlated for the traits describing pigment ‘darkness’ only. While the model including scores based on human naked eyes explained 16% of the variance of pigment concentration in the entire shell, spectrometry explained 27%, and the granularity approach explained 40%. Thus, the estimation of true pigment concentration in the entire shell from the visible outer side of the shell is most reliable with the granularity approach. It is relevant for studies where the maintenance of the integrity of the eggs is essential.     

New data on aphid fauna (Hemiptera,Aphididae) in?Algeria

A survey of aphids was carried out during the period 2008-2011 in different regions of Algeria by collecting and identifying aphids and their host plants. Aphids were collected from 46 host plants. Forty-six species were reported including thirty-six species which were recorded for the first time in this country and thirty species which were recorded for the first time in the Maghreb (North Africa). This study extends the number of known Algerian aphid to 156 species.     

Medicinal plants and phytochemicals against multidrug-resistant tumor cells expressing ABCB1, ABCG2, or ABCB5: a synopsis of 2 decades

Phytochemistry Reviews - Multidrug resistance is a major factor causing the failure of cancer chemotherapy. Efflux pumps of the ATP-binding cassette (ABC) transporter family expel a large array of...     

TiO2 Nanocrystals Synthesized by Laser Pyrolysis for the Up‐Scaling of Efficient Solid‐State Dye‐Sensitized Solar Cells

A crucial issue regarding emerging nanotechnologies remains the up‐scaling of new functional nanostructured materials towards their implementation in high performance applications on a large scale. In this context, we demonstrate high efficiency solid‐state dye‐sensitized solar cells prepared from new porous TiO₂ photoanodes based on laser pyrolysis nanocrystals. This strategy exploits a reduced number of processing steps as well as non‐toxic chemical compounds to demonstrate highly porous TiO₂ films. The possibility to easily tune the TiO₂ nanocrystal physical properties allows us to demonstrate all solid‐state dye‐sensitized devices based on a commercial benchmark materials (organic indoline dye and molecular hole transporter) presenting state‐of‐the‐art performance comparable with reference devices based on a commercial TiO₂ paste. In particular, a drastic improvement in pore infiltration, which is found to balance a relatively lower surface area compared to the reference electrode, is evidenced using laser‐synthesized nanocrystals resulting in an improved short‐circuit current density under full sunlight. Transient photovoltage decay measurements suggest that charge recombination kinetics still limit device performance. However, the proposed strategy emphasizes the potentialities of the laser pyrolysis technique for up‐scaling nanoporous TiO₂ electrodes for various applications, especially for solar energy conversion.