Disulfide cross-links in the interaction of a cataract-linked αA-crystallin mutant with βB1-crystallin

AbstractA number of αA-crystallin mutants are associated with hereditary cataract including cysteine substitution at arginine 49. We report the formation of affinity-driven disulfide bonds in the interaction of αA-R49C with βB1-crystallin. To mimic cysteine thiolation in the lens, βB1-crystallin was modified by a bimane probe through a disulfide linkage. Our data suggest a mechanism whereby a transient disulfide bond occurs between αA- and βB1-crystallin followed by a disulfide exchange with cysteine 49 of a neighboring αA-crystallin subunit. This is the first investigation of disulfide bonds in the confine of the chaperone/substrate complex where reaction rates are favored by orders of magnitude. Covalent protein cross-links are a hallmark of age-related cataract and may be a factor in its inherited form

Moroccan rock phosphate solubilization during a thermo-anaerobic grassland waste biodegradation process

In order to investigate the presence of thermo-tolerant rock phosphate (RP) solubilizing anaerobic microbes during the fermentation process, we used grassland as sole organic substrate to evaluate the RP solubilization process under anaerobic thermophilic conditions. The result shows a significant decrease of pH from 6.5 to 4.8, and solubilizing from 7 to 15.8% of the phosphorus from the RP in the reactors after 90 days of incubation at 45°C. In these conditions, the organic acids produced were qualitatively and quantitatively identified as: acetic, butyric and propionic acids. This biological RP solubilization is due to the presence of a single thermo-tolerant bacterium isolated and identified as Bacillus subtilis from the anaerobic reactors. This B. subtilis strain was shown to be able to solubilize RP in liquid cultures containing insoluble RP as sole phosphate source. The mechanisms involved in these weathering processes confirmed the production of organic acids which were identified and quantified. This study is expected to lead to the development of novel, non-polluting farming practices by entering in the formulation of novel multi-functional biofertilizer by inoculating this thermo-tolerant phosphate-solubilizing bacterium into agricultural wastes as a practical and environmental strategy.Key words: Grassland, phosphate, solubilization, Bacillus subtilis, thermo-anaerobic conditions

Une tumeur du vagin à ne pas méconnaitre, l’adénocarcinome mésonephrique: à propos d’un cas et revue de la literature

L'adénocarcinome mésonéphrique du vagin est une tumeur maligne extrêmement rare avec uniquement trois cas publiés dans la littérature jusqu'à maintenant. Il dérive des reliquats embryonnaires des canaux mésonéphriques au niveau du vagin. Nous rapportons un cas d'adénocarcinome mésonéphrique du vagin survenant chez une femme de 50 ans, et révélé par une masse polyploïde du vagin. L'IRM a montré un envahissement du périnée et de la branche inférieure du pubis. L'étude anatomo-pathologique était en faveur d'un adénocarcinome mésonéphrique dont les cellules tumorales expriment la pancytokératine et le CD10. Elles ne sont pas marquées par les anticorps anti récepteurs ostrogéniques et progestatifs. La patiente a été adressée pour radiothérapie avant la prise en charge chirurgicale. Les auteurs soulignent à travers cette observation les aspects étiopathogéniques, histologiques et thérapeutiques de cette tumeur rare

The Electrophoretic Profile Myofibrillar Proteins Extracted From Camel Muscles, Kept in Various Modes

Changes in electrophoretic profiles of myofibrillar protein (MFP) in the Longissimus thoracis (LD) of young camels (2 to 4 years), preserved by refrigeration has been treated or not by lactic acid solution 4% or citric acid 1%, were followed during the post-mortem time at the following times: 1, 2, 4, 6, 8, 10, 12, 24 and 48 hours. The cold preservation for 48 hours has not shown any particular distinctions in the protein profiles of this muscle. Changes related to the type of treatment were recorded during the storage time. Proteolysis of the myofibrillar fraction was earlier in this muscle in the case of treatment with one of two solutions of organic acids used, particularly in the case of using lactic acid. Indeed, these changes have affected at the first hour after slaughter the proteolysis of the myofibrillar proteins. Fragments of low molecular weight (42, 36, 33, 26, 23, 18, 16, 14 and 13 kDa) have been identified. The electrophoretic analysis showed that during refrigeration, LD treated with a solution of lactic acid is more sensitive to disruption phenomena and muscle protein proteolysis that lots of this muscle that even in the case of preservation by refrigeration only or by refrigeratio

In Vivo bone tissue induction by freeze-dried collagen-nanohydroxyapatite matrix loaded with BMP2/NS1 mRNAs lipopolyplexes

Messenger RNA (mRNA) activated matrices (RAMs) are interesting to orchestrate tissue and organ regeneration due to the in-situ and sustained production of functional proteins. However, the immunogenicity of in vitro transcribed mRNA and the paucity of proper in vivo mRNA delivery vector need to be overcome to exert the therapeutic potential of RAM. We developed a dual mRNAs system for in vitro osteogenesis by co-delivering NS1 mRNA with BMP2 mRNA to inhibit RNA sensors and enhance BMP-2 expression. Next, we evaluated a lipopolyplex (LPR) formulation platform for in vivo mRNA delivery and adapted the LPRs for RAM preparation. The LPR formulated BMP2/NS1 mRNAs were incorporated into an optimized collagen-nanohydroxyapatite scaffold and freeze-dried to prepare ready-to-use RAMs. The loaded BMP2/NS1 mRNAs lipopolyplexes maintained their spherical morphology in the RAM, thanks to the core-shell structure of LPR. The mRNAs release from RAMs lasted for 16 days resulting in an enhanced prolonged transgene expression period compared to direct cell transfection. Once subcutaneously implanted in mice, the BMP2/NS1 mRNAs LPRs containing RAMs (RAM-BMP2/NS1) induced significant new bone tissue than those without NS1 mRNA, eight weeks post implantation. Overall, our results demonstrate that the BMP2/NS1 dual mRNAs system is suitable for osteogenic engagement, and the freeze-dried RAM-BMP2/NS1 could be promising off-the-shelf products for clinical orthopedic practice.info:eu-repo/semantics/publishedVersio

Mechanically Induced Amorphization of Diaqua-bis(Omeprazolate)-Magnesium Dihydrate

The influence of milling diaqua-bis(omeprazolate)-magnesium dihydrate (DABOMD), an active pharmaceutical ingredient (API), was investigated. DABOMD was processed in a planetary ball mill at different milling times, from 1 to 300 min. The milling process resulted in a prominent comminution (size reduction) and amorphization of the API. DABOMD amorphization was identified with various characterization techniques including thermogravimetric analysis, differential scanning calorimetry, powder X-ray diffraction, and attenuated total reflection-Fourier transform infrared spectroscopy. The solid–solid crystalline to amorphous phase transformation is driven by compression, shear stresses, and heat generated in the planetary ball mill. This leads to distortion and breakage of hydrogen bonds, release of water molecules from the crystalline lattice of DABOMD and the accumulation of defects, and eventually a collapse of the crystalline order. Model fitting of the kinetics of comminution and the amorphization of DABOMD revealed a series of events: a rapid comminution at the start of milling driven by crystal cleavage of DABOMD, followed by partial amorphization, which is driven by rapid water diffusion, and subsequently, a slow steady comminution and amorphization

PREDON Scientific Data Preservation 2014

LPSC14037Scientific data collected with modern sensors or dedicated detectors exceed very often the perimeter of the initial scientific design. These data are obtained more and more frequently with large material and human efforts. A large class of scientific experiments are in fact unique because of their large scale, with very small chances to be repeated and to superseded by new experiments in the same domain: for instance high energy physics and astrophysics experiments involve multi-annual developments and a simple duplication of efforts in order to reproduce old data is simply not affordable. Other scientific experiments are in fact unique by nature: earth science, medical sciences etc. since the collected data is "time-stamped" and thereby non-reproducible by new experiments or observations. In addition, scientific data collection increased dramatically in the recent years, participating to the so-called "data deluge" and inviting for common reflection in the context of "big data" investigations. The new knowledge obtained using these data should be preserved long term such that the access and the re-use are made possible and lead to an enhancement of the initial investment. Data observatories, based on open access policies and coupled with multi-disciplinary techniques for indexing and mining may lead to truly new paradigms in science. It is therefore of outmost importance to pursue a coherent and vigorous approach to preserve the scientific data at long term. The preservation remains nevertheless a challenge due to the complexity of the data structure, the fragility of the custom-made software environments as well as the lack of rigorous approaches in workflows and algorithms. To address this challenge, the PREDON project has been initiated in France in 2012 within the MASTODONS program: a Big Data scientific challenge, initiated and supported by the Interdisciplinary Mission of the National Centre for Scientific Research (CNRS). PREDON is a study group formed by researchers from different disciplines and institutes. Several meetings and workshops lead to a rich exchange in ideas, paradigms and methods. The present document includes contributions of the participants to the PREDON Study Group, as well as invited papers, related to the scientific case, methodology and technology. This document should be read as a "facts finding" resource pointing to a concrete and significant scientific interest for long term research data preservation, as well as to cutting edge methods and technologies to achieve this goal. A sustained, coherent and long term action in the area of scientific data preservation would be highly beneficial

Loss of endothelial membrane KIT ligand affects systemic KIT ligand levels but not bone marrow hematopoietic stem cells

A critical regulatory role of hematopoietic stem cell (HSC) vascular niches in the bone marrow has been implicated to occur through endothelial niche cell expression of KIT ligand. However, endothelial-derived KIT ligand is expressed in both a soluble and membrane-bound form and not unique to bone marrow niches, and it is also systemically distributed through the circulatory system. Here, we confirm that upon deletion of both the soluble and membrane-bound forms of endothelial-derived KIT ligand, HSCs are reduced in mouse bone marrow. However, the deletion of endothelial-derived KIT ligand was also accompanied by reduced soluble KIT ligand levels in the blood, precluding any conclusion as to whether the reduction in HSC numbers reflects reduced endothelial expression of KIT ligand within HSC niches, elsewhere in the bone marrow, and/or systemic soluble KIT ligand produced by endothelial cells outside of the bone marrow. Notably, endothelial deletion, specifically of the membrane-bound form of KIT ligand, also reduced systemic levels of soluble KIT ligand, although with no effect on stem cell numbers, implicating an HSC regulatory role primarily of soluble rather than membrane KIT ligand expression in endothelial cells. In support of a role of systemic rather than local niche expression of soluble KIT ligand, HSCs were unaffected in KIT ligand deleted bones implanted into mice with normal systemic levels of soluble KIT ligand. Our findings highlight the need for more specific tools to unravel niche-specific roles of regulatory cues expressed in hematopoietic niche cells in the bone marrow

Genotype tunes pancreatic ductal adenocarcinoma tissue tension to induce matricellular fibrosis and tumor progression

Fibrosis compromises pancreatic ductal carcinoma (PDAC) treatment and contributes to patient mortality yet anti-stromal therapies are controversial. We found that human PDACs with impaired epithelial transforming growth factor β (TGF-β) signaling have elevated epithelial Stat3 activity and develop a stiffer, matricellular-enriched fibrosis associated with high epithelial tension and shorter patient survival. In several Kras-driven mouse models, both the loss of TGF-β signaling and elevated β1-integrin mechanosignaling engaged a positive feedback loop whereby Stat3 signaling promotes tumor progression by increasing matricellular fibrosis and tissue tension. In contrast, epithelial Stat3 ablation attenuated tumor progression by reducing the stromal stiffening and epithelial contractility induced by loss of TGF-β signaling. In PDAC patient biopsies, higher matricellular protein and activated Stat3 associated with SMAD4 mutation and shorter survival. The findings implicate epithelial tension and matricellular fibrosis in the aggressiveness of SMAD4 mutant pancreatic tumors, and highlight Stat3 and mechanics as key drivers of this phenotype