Pre-irradiation dental care: Ready-to-use templates for oropharyngeal cancers

Aim

To develop a tool in order to guide pre-irradiation dental care (PIDC) for patients with oropharyngeal cancers.

Contraceptive steroids from pharmaceutical waste perturbate junctional communication in Sertoli cells

The potential health impact of pharmaceutical waste is now a growing concern. Contraceptive steroids are prominent environmental contaminants and thus may act as endocrine disruptors. Numerous xenobiotics hamper Sertoli cells junctional communication which is known to participate in spermatogenesis control. This has been associated with male subfertility and testicular cancer. We investigated three contraceptive molecules found in the environment for their potential impact on Sertoli cells gap junction functionality: 17a-ethynylestradiol, medroxyprogesterone acetate and levonorgestrel. Four other non-steroid drugs also found in the environment were included in the study. Communication disruption was analyzed in vitro in murine seminiferous tubules and the 42GPA9 Sertoli cell line. Steroids modulated connexin43 trafficking and impaired junctional communication through rapid effects apparently acting on the cell membrane but not on Cx43 expression. The 4 non-steroid compounds showed no effect. Longer exposure to steroids increased gap junction impairment, which was associated in part with Na/K ATPase internalization. Estrogen receptors (ER) did not appear to be involved in gap junction disruption: Sertoli cells are devoid of ERα and only express the cytoplasmic β isoform. ERβ localization was not modified by either steroid. The threshold level was surprisingly low, around 10^?16 M. We conclude that steroidal pollutants disrupt Sertoli cells junctional communication in vitro at concentrations that can be found in the environment.     

A 1,100-year-old founder effect mutation in IL12B gene is responsible for Mendelian susceptibility to mycobacterial disease in Tunisian patients

Mendelian susceptibility to mycobacterial disease (MSMD) is a rare disorder predisposing apparently healthy individuals to infections caused by weakly virulent mycobacteria such as bacille Calmette–Guerin (BCG), environmental mycobacteria, and poorly virulent Salmonella strains. IL-12p40 deficiency is the first reported human disease due to a cytokine gene defect and is one of the deficiencies that cause MSMD. Nine mutant alleles only have been identified in the IL12B gene, and three of them are recurrent mutations due to a founder effect in specific populations. IL-12p40 deficiency has been identified especially in countries where consanguinity is high and where BCG vaccination at birth is universal. We investigated, in such settings, the clinical, cellular, and molecular features of six IL-12p40-deficient Tunisian patients having the same mutation in IL12B gene (c.298_305del). We found that this mutation is inherited as a common founder mutation arousing ~1,100 years ago. This finding facilitates the development of a preventive approach by genetic counseling and prenatal diagnosis especially in affected families.     

Molecular community analysis of magnesium-rich bittern brine recovered from a Tunisian solar saltern

The microbial community of a magnesium-rich bittern brine saturated with NaCl (380-400 g/L) from a Tunisian solar saltern was investigated using a molecular approach based on 16S rRNA gene analysis and viability tests. The results revealed the existence of microbial flora. Viability test assessment showed that 46.4% of this flora was viable but not detectable by culturability tests. 16S rRNA genes from 49 bacterial clones and 38 archaeal clones were sequenced and phylogenetically analyzed. Eleven operational taxonomic units (OTUs) determined by the DOTUR program with 97% sequence similarity were generated for Bacteria. These OTUs were affiliated with Bacteroidetes and Gammaproteobacteria. The archaeal community composition exhibited more diversity with 38 clones, resulting in 13 OTUs affiliated with the Euryarchaeota phylum. Diversity measurement showed a more diverse archaeal than bacterial community at the saturated pond.     

Ion uptake and structural modifications induced by nitrogen source in tomato (Solanum lycopersicum Mill. Cv. Ibiza F1)

Interactions between NO(3)(-) and NO(2)(-) were studied at the level of root uptake, ion translocation (NO(3)(-), NO(2)(-), K(+)), ion xylem exudates composition and inorganic cation contents (K(+), Ca(2+), Mg(2+)) using tomato seedling (Solanum lycopersicum Mill cv. Ibiza F1). Nitrite was supplied in the medium as KNO(2) (0, 0.25, 2.5, 5 and 10?mM). Plants cultivated on the same doses of KNO(3) served as control. The experimental system allowed direct measurements of net NO(3)(-) and NO(2)(-) uptake. Our results showed that NO(3)(-) uptake and translocation were stimulated by external supply of K(+), while they were hardly decreased by NO(2)(-) supply. Contents of K(+) and Mg(2+) were negatively affected in all tomato tissues by increasing nitrite concentration in the medium. Highest dose of NO(2)(-) decreased Ca(2+) accumulation in shoots and conversely increased that in the roots. Histological study at the stem level revealed that nitrite (10?mM) induced a restriction of the tissue territories as well as less developed regions and some conductor tissues disorganization in this organ structure. The overall results suggest that nitrite exposure delayed growth and injured cell structure and overall nutrient uptake.     

Choroid Sprouting Assay: An Ex Vivo Model of Microvascular Angiogenesis

Angiogenesis of the microvasculature is central to the etiology of many diseases including proliferative retinopathy, age-related macular degeneration and cancer. A mouse model of microvascular angiogenesis would be very valuable and enable access to a wide range of genetically manipulated tissues that closely approximate small blood vessel growth in vivo. Vascular endothelial cells cultured in vitro are widely used, however, isolating pure vascular murine endothelial cells is technically challenging. A microvascular mouse explant model that is robust, quantitative and can be reproduced without difficulty would overcome these limitations. Here we characterized and optimized for reproducibility an organotypic microvascular angiogenesis mouse and rat model from the choroid, a microvascular bed in the posterior of eye. The choroidal tissues from C57BL/6J and 129S6/SvEvTac mice and Sprague Dawley rats were isolated and incubated in Matrigel. Vascular sprouting was comparable between choroid samples obtained from different animals of the same genetic background. The sprouting area, normalized to controls, was highly reproducible between independent experiments. We developed a semi-automated macro in ImageJ software to allow for more efficient quantification of sprouting area. Isolated choroid explants responded to manipulation of the external environment while maintaining the local interactions of endothelial cells with neighboring cells, including pericytes and macrophages as evidenced by immunohistochemistry and fluorescence-activated cell sorting (FACS) analysis. This reproducible ex vivo angiogenesis assay can be used to evaluate angiogenic potential of pharmacologic compounds on microvessels and can take advantage of genetically manipulated mouse tissue for microvascular disease research.     

Probing the Crucial Role of Leu31 and Thr33 of the Bacillus pumilus CBS Alkaline Protease in Substrate Recognition and Enzymatic Depilation of Animal Hide

The sapB gene, encoding Bacillus pumilus CBS protease, and seven mutated genes (sapB-L31I, sapB-T33S, sapB-N99Y, sapB-L31I/T33S, sapB-L31I/N99Y, sapB-T33S/N99Y, and sapB-L31I/T33S/N99Y) were overexpressed in protease-deficient Bacillus subtilis DB430 and purified to homogeneity. SAPB-N99Y and rSAPB displayed the highest levels of keratinolytic activity, hydrolysis efficiency, and enzymatic depilation. Interestingly, and at the semi-industrial scale, rSAPB efficiently removed the hair of goat hides within a short time interval of 8 h, thus offering a promising opportunity for the attainment of a lime and sulphide-free depilation process. The efficacy of the process was supported by submitting depilated pelts and dyed crusts to scanning electron microscopic analysis, and the results showed well opened fibre bundles and no apparent damage to the collagen layer. The findings also revealed better physico-chemical properties and less effluent loads, which further confirmed the potential candidacy of the rSAPB enzyme for application in the leather industry to attain an ecofriendly process of animal hide depilation. More interestingly, the findings on the substrate specificity and kinetic properties of the enzyme using the synthetic peptide para-nitroanilide revealed strong preferences for an aliphatic amino-acid (valine) at position P1 for keratinases and an aromatic amino-acid (phenylalanine) at positions P1/P4 for subtilisins. Molecular modeling suggested the potential involvement of a Leu31 residue in a network of hydrophobic interactions, which could have shaped the S4 substrate binding site. The latter could be enlarged by mutating L31I, fitting more easily in position P4 than a phenylalanine residue. The molecular modeling of SAPB-T33S showed a potential S2 subside widening by a T33S mutation, thus suggesting its importance in substrate specificity.     

Polymeric IgA1 controls erythroblast proliferation and accelerates erythropoiesis recovery in anemia

Anemia because of insufficient production of and/or response to erythropoietin (Epo) is a major complication of chronic kidney disease and cancer. The mechanisms modulating the sensitivity of erythroblasts to Epo remain poorly understood. We show that, when cultured with Epo at suboptimal concentrations, the growth and clonogenic potential of erythroblasts was rescued by transferrin receptor 1 (TfR1)-bound polymeric IgA1 (pIgA1). Under homeostatic conditions, erythroblast numbers were increased in mice expressing human IgA1 compared to control mice. Hypoxic stress of these mice led to increased amounts of pIgA1 and erythroblast expansion. Expression of human IgA1 or treatment of wild-type mice with the TfR1 ligands pIgA1 or iron-loaded transferrin (Fe-Tf) accelerated recovery from acute anemia. TfR1 engagement by either pIgA1 or Fe-Tf increased cell sensitivity to Epo by inducing activation of mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) signaling pathways. These cellular responses were mediated through the TfR1-internalization motif, YXXΦ. Our results show that pIgA1 and TfR1 are positive regulators of erythropoiesis in both physiological and pathological situations. Targeting this pathway may provide alternate approaches to the treatment of ineffective erythropoiesis and anemia.