Eukaryotic DING Proteins Are Endogenous: An Immunohistological Study in Mouse Tissues

BACKGROUND: DING proteins encompass an intriguing protein family first characterized by their conserved N-terminal sequences. Some of these proteins seem to have key roles in various human diseases, e.g., rheumatoid arthritis, atherosclerosis, HIV suppression. Although this protein family seems to be ubiquitous in eukaryotes, their genes are consistently lacking from genomic databases. Such a lack has considerably hampered functional studies and has fostered therefore the hypothesis that DING proteins isolated from eukaryotes were in fact prokaryotic contaminants. PRINCIPAL FINDINGS: In the framework of our study, we have performed a comprehensive immunological detection of DING proteins in mice. We demonstrate that DING proteins are present in all tissues tested as isoforms of various molecular weights (MWs). Their intracellular localization is tissue-dependant, being exclusively nuclear in neurons, but cytoplasmic and nuclear in other tissues. We also provide evidence that germ-free mouse plasma contains as much DING protein as wild-type. SIGNIFICANCE: Hence, data herein provide a valuable basis for future investigations aimed at eukaryotic DING proteins, revealing that these proteins seem ubiquitous in mouse tissue. Our results strongly suggest that mouse DING proteins are endogenous. Moreover, the determination in this study of the precise cellular localization of DING proteins constitute a precious evidence to understand their molecular involvements in their related human diseases

Case Report: Longitudinal follow-up and testicular sperm extraction in a patient with a pathogenic NR5A1 (SF-1) frameshift variant: p.(Phe70Serfs*5)

BackgroundSteroidogenic factor 1 (SF-1), encoded by the nuclear receptor subfamily 5 group A member 1 (NR5A1) gene, is a transcriptional factor crucial for adrenal and gonadal organogenesis. Pathogenic variants of NR5A1 are responsible for a wide spectrum of phenotypes with autosomal dominant inheritance including disorders of sex development and oligospermia–azoospermia in 46,XY adults. Preservation of fertility remains challenging in these patients.ObjectiveThe aim was to offer fertility preservation at the end of puberty in an NR5A1 mutated patient.Case reportThe patient was born of non-consanguineous parents, with a disorder of sex development, a small genital bud, perineal hypospadias, and gonads in the left labioscrotal fold and the right inguinal region. Neither uterus nor vagina was detected. The karyotype was 46,XY. Anti-Müllerian hormone (AMH) and testosterone levels were low, indicating testicular dysgenesis. The child was raised as a boy. At 9 years old, he presented with precocious puberty treated by triptorelin. At puberty, follicle-stimulating hormone (FSH), luteinising hormone (LH), and testosterone levels increased, whereas AMH, inhibin B, and testicular volume were low, suggesting an impaired Sertoli cell function and a partially preserved Leydig cell function. A genetic study performed at almost 15 years old identified the new frameshift variant NM_004959.5: c.207del p.(Phe70Serfs*5) at a heterozygous state. He was thus addressed for fertility preservation. No sperm cells could be retrieved from three semen collections between the ages of 16 years 4 months and 16 years 10 months. A conventional bilateral testicular biopsy and testicular sperm extraction were performed at 17 years 10 months of age, but no sperm cells were found. Histological analysis revealed an aspect of mosaicism with seminiferous tubules that were either atrophic, with Sertoli cells only, or presenting an arrest of spermatogenesis at the spermatocyte stage.ConclusionWe report a case with a new NR5A1 variant. The fertility preservation protocol proposed at the end of puberty did not allow any sperm retrieval for future parenthood

Structuration and deformation of colloidal hydrogels

International audienceThe aim of the present paper is to determine the optimum conditions for the formation of homogeneous colloidal silica hydrogels by aggregation and drying processes, avoiding mechanical instabilities at the surface. Aggregation is controlled by adding monovalent salt to the silica nanoparticle suspension while the drying of the sol is also modulated by changing the evaporation rate.A phase diagram reveals two regions in the parameter plane, ionic strength versus evaporation rate: a region where the drop undergoes an isotropic shrinkage and forms the required homogeneous gel and a region where mechanical instabilities appear due to the formation of a solid skin at the gel surface. The frontier between these two regions can be determined by equating the following two characteristic times: the gelation time and the time for skin formation. Permeability measurements of the final gel provide an estimate of the drying stress, which is compared to the yield stress of the material. In accordance with the determined phase diagram, our study shows that instabilities appear when the drying stress is larger than the yield stress

Contribution of the active-site metal cation to the catalytic activity and to the conformational stability of phosphotriesterase: temperature- and pH-dependence.

Phosphotriesterase (PTE) detoxifies nerve agents and organophosphate pesticides. The two zinc cations of the PTE active centre can be substituted by other transition metal cations without loss of activity. Furthermore, metal-substituted PTEs display differences in catalytic properties. A prerequisite for engineering highly efficient mutants of PTE is to improve their thermostability. Isoelectric focusing, capillary electrophoresis and steady-state kinetics analysis were used to determine the contribution of the active-site cations Zn2+, Co2+ or Cd2+ to both the catalytic activity and the conformational stability of the corresponding PTE isoforms. The three isoforms have different pI values (7.2, 7.5 and 7.1) and showed non-superimposable electrophoretic titration curves. The overall structural alterations, causing changes in functional properties, were found to be related to the nature of the bound cation: ionic radius and ion electronegativity correlate with Km and kcat respectively. In addition, the pH-dependent activity profiles of isoforms were different. The temperature-dependent profiles of activity showed maximum activity at T < or =35 degrees C, followed by an activation phase near 45-48 degrees C and then inactivation which was completed at 60 degrees C. Analysis of thermal denaturation of the PTEs provided evidence that the activation phase resulted from a transient intermediate. Finally, at the optimum activity between pH 8 and 9.4, the thermostability of the different PTEs increased as the pH decreased, and the metal cation modulated stability (Zn2+-, Co2+- and Cd2+-PTE showed different T (m) values of 60.5-67 degrees C, 58-64 degrees C and 53-64 degrees C respectively). Requirements for optimum activity of PTE (displayed by Co2+-PTE) and maximum stability (displayed by Zn2+-PTE) were demonstrated

Adaptation strategies of soil biodiversity (earthworms) to pesticides: From physiological changes to soil ecological implications

International audienc

Adaptation strategies of soil biodiversity (earthworms) to pesticides: From physiological changes to soil ecological implications

International audienc

Acclimation of earthworms to chemicals in anthropogenic landscapes, physiological mechanisms and soil ecological implications

Because earthworms sustain soil functioning and fertility, there is a need to advance the knowledge of their adaptation potential to chemicals in anthropogenic landscapes. Our hypothesis is that there is acclimation to organic chemicals (pesticides) in earthworms that durably persist under conventional farming in anthropogenic landscapes. The adaptation capability of two populations of earthworms (Aporectodea caliginosa) having a different chemical exposure history, - one originating from 20 years of organic farming (naïve population) and another from 20 years of conventional farming (pre-exposed population) - to cope with soil organic pollutant (Opus®, epoxiconazole a worldwide used fungicide) were investigated. Several complementary metabolic and energetic endpoints were followed, and cast production was assessed as a behavioural biomarker related to earthworms ecological role for the soil. Basal metabolism reflected by respiration rate was increased in both fungicide-exposed worms compared to controls. Glycogen resources were decreased in the same proportion in the two populations but more rapidly for the naïve (7 days) than for the pre-exposed population (28 days). Soluble protein and most amino-acids contents increased in the pre-exposed population only, suggesting a detoxification mechanism. Metabolomic profiles showed a cut-off between fungicide-exposed and control groups in the pre-exposed earthworms only, with an increase in most of the metabolites. Exposure to a low dose of epoxiconazole increased cast production of pre-exposed earthworms, and this resulted in an increase in pesticide disappearance. As far as we know, this is the first study which evidenced there is an acclimation to an agricultural chemical in earthworms derived from conventional farming that also relates to a change in their burrowing behaviour, and for which larger consequences for the soil ecosystem need to be addressed. This original finding is of major interest in the frame of ecosystem resilience to global changes. Whether this physiological adaptation is a general pattern of response against fungicides or other pesticides would need to be confirmed with other molecules and agricultural contexts

Oligomeric States of the Detergent-solubilized Human Serum Paraoxonase (PON1)

International audienc

Chemiluminescence of Luminol for the Determination of Cobalt(II) Adsorbed on a Chitosan Membrane

Proceedings Paper: 6th Maghreb-Europe Meeting on Materials and Their Applications for Devices and Physical, Chemical and Biological Sensors, Rabat, Morocco, 2008International audienceIn this work chemiluminescence (CL) of luminol was used for the determination of Co(II). This method is based on the fact that Co(II) catalyzes the CL reaction of luminol in the presence of H2O2. The optimization of the conditions of CL measurements in a liquid system (effect of luminol and H2O2 concentrations) is studied. This method has shown a remarkable sensitivity until 4 fg/L of Co(II) as detection limit. The linear range extends from 0.4 pg/L to 40 mu g/L of Co(II). The optimum conditions for the preparation of the chitosan membranes for the adsorption of cobalt ions were studied. The analytical characteristics of the membrane/liquid CL system are similar to those of the CL liquid system. The preconcentration of cobalt ions on the chitosan membrane presented here opens up possibilities for a number of biomedical applications for determination of Vitamin B-12 containing a cobalt ion in pharmaceuticals, human serum, egg yolk and fish tissue, and for environmental applications for the detection of cobalt in soils and river waters