Publications (40) View all
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Article: An increase in milk IgA correlates with both pIgR expression and IgA plasma cell accumulation in the lactating mammary gland of PRM/Alf mice.
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ABSTRACT: In mice, during late pregnancy and lactation, maternal precursors of IgA-containing cells (cIgA-cells) are primed in the gut and home to the mammary gland where they secrete IgA. In turn, the ensuing increase in milk IgA mediates immune protection of the newborn gastrointestinal tract. PRM/Alf is an inbred mouse strain which exhibits a substantial post-natal intestinal lengthening which develops throughout the neonatal suckling period, suggesting that the availability of cIg-A cells and the level of protective IgA in milk might also be increased. We confirmed that PRM/Alf milk contains higher amounts of IgA than C57BL/6J throughout lactation, concomitantly with an increase of pIgR on epithelial cells and a higher density of cIgA-cells in the PRM/Alf mammary gland. Furthermore, a search for variations in cellular and humoral factors implicated in regulating cIgA-cell migration towards the mammary gland, including the vascular addressins MAdCAM-1 (mucosal addressin cell adhesion molecule-1) and VCAM-1 (vascular cell adhesion molecule-1) as well as the mucosal epithelial chemokine CCL28, did not reveal any quantitative differences in expression between PRM/Alf and C57BL/6J mice strains. Thus our results indicate that these factors are not limiting in the recruitment of cIgA-cells released from the elongated gut of PRM/Alf mice. In the context of intestinal lengthening, these findings strengthen the notion of an entero-mammary gland link, where the neonatal gut is protected by the maternal gut through the immune function of the mammary gland.Journal of Reproductive Immunology 09/2012; · 2.97 Impact Factor -
Article: Transcriptome profiling of sheep granulosa cells and oocytes during early follicular development obtained by laser capture microdissection.
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ABSTRACT: Successful achievement of early folliculogenesis is crucial for female reproductive function. The process is finely regulated by cell-cell interactions and by the coordinated expression of genes in both the oocyte and in granulosa cells. Despite many studies, little is known about the cell-specific gene expression driving early folliculogenesis. The very small size of these follicles and the mixture of types of follicles within the developing ovary make the experimental study of isolated follicular components very difficult.The recently developed laser capture microdissection (LCM) technique coupled with microarray experiments is a promising way to address the molecular profile of pure cell populations. However, one main challenge was to preserve the RNA quality during the isolation of single cells or groups of cells and also to obtain sufficient amounts of RNA.Using a new LCM method, we describe here the separate expression profiles of oocytes and follicular cells during the first stages of sheep folliculogenesis. We developed a new tissue fixation protocol ensuring efficient single cell capture and RNA integrity during the microdissection procedure. Enrichment in specific cell types was controlled by qRT-PCR analysis of known genes: six oocyte-specific genes (SOHLH2, MAEL, MATER, VASA, GDF9, BMP15) and three granulosa cell-specific genes (KL, GATA4, AMH).A global gene expression profile for each follicular compartment during early developmental stages was identified here for the first time, using a bovine Affymetrix chip. Most notably, the granulosa cell dataset is unique to date. The comparison of oocyte vs. follicular cell transcriptomes revealed 1050 transcripts specific to the granulosa cell and 759 specific to the oocyte.Functional analyses allowed the characterization of the three main cellular events involved in early folliculogenesis and confirmed the relevance and potential of LCM-derived RNA. The ovary is a complex mixture of different cell types. Distinct cell populations need therefore to be analyzed for a better understanding of their potential interactions. LCM and microarray analysis allowed us to identify novel gene expression patterns in follicular cells at different stages and in oocyte populations.BMC Genomics 08/2011; 12:417. · 4.07 Impact Factor -
Article: IL6 and TNF expression in vessels and surrounding tissues after embolization with ibuprofen-loaded beads confirms diffusion of ibuprofen.
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ABSTRACT: In the treatment of uterine fibroid embolization related pain, the use of embolics loaded with non-steroidal anti-inflammatory drugs (NSAID) relies on an efficient delivery and impregnation of the embolized tissue. Immuno-labelling and spectroscopic techniques have demonstrated the release of ibuprofen from drug eluting beads (Wassef et al., 2008; Namur et al., 2009) but failed to demonstrate diffusion of the drug beyond the vascular wall (VW). We investigated whether ibuprofen diffused beyond the VW in surrounding tissues (ST), by tracking its biological effects through the modulation of expression of two main inflammatory cytokines. Uterine arteries of 6 sheep were embolized with ibuprofen loaded beads (IBU-BB) or non-loaded beads (BB) and sacrificed at one week. On frozen tissue slices, VWs of occluded arteries were isolated from ST using laser capture microdissection. RNA was extracted from VW and ST samples. Gene expression of IL6 and TNFα genes was measured by quantitative real-time PCR (qPCR). IL6 expression was significantly increased in IBU-BB compared to BB group both in VW (VW: fold-change (FC)=4.9, p=0.0009) and ST (ST: FC=8.7, p=0.0003). In IBU-BB, IL6 was significantly more expressed in VW than in ST (FC=4.4; p=0.0009). TNFα expression was not significantly different between IBU-BB and BB groups. Using qPCR+microdissection was useful to evaluate the spread of the biological effects of drug-loaded systems which attest of the tissular release. This approach can be considered when other drug detection techniques are unsuccessful or difficult to achieve. IL6 can be used as a marker of ibuprofen released by drug eluting beads in uterus. Gradient of expression of IL6 suggests diffusion of ibuprofen across the VW into the ST.European journal of pharmaceutical sciences: official journal of the European Federation for Pharmaceutical Sciences 02/2011; 42(5):489-95. · 2.61 Impact Factor -
Article: Evolution of major milk proteins in Mus musculus and Mus spretus mouse species: a genoproteomic analysis.
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ABSTRACT: Due to their high level of genotypic and phenotypic variability, Mus spretus strains were introduced in laboratories to investigate the genetic determinism of complex phenotypes including quantitative trait loci. Mus spretus diverged from Mus musculus around 2.5 million years ago and exhibits on average a single nucleotide polymorphism (SNP) in every 100 base pairs when compared with any of the classical laboratory strains. A genoproteomic approach was used to assess polymorphism of the major milk proteins between SEG/Pas and C57BL/6J, two inbred strains of mice representative of Mus spretus and Mus musculus species, respectively. The milk protein concentration was dramatically reduced in the SEG/Pas strain by comparison with the C57BL/6J strain (34 ± 9 g/L vs. 125 ± 12 g/L, respectively). Nine major proteins were identified in both milks using RP-HPLC, bi-dimensional electrophoresis and MALDI-Tof mass spectrometry. Two caseins (β and αs1) and the whey acidic protein (WAP), showed distinct chromatographic and electrophoresis behaviours. These differences were partly explained by the occurrence of amino acid substitutions and splicing variants revealed by cDNA sequencing. A total of 34 SNPs were identified in the coding and 3'untranslated regions of the SEG/Pas Csn1s1 (11), Csn2 (7) and Wap (8) genes. In addition, a 3 nucleotide deletion leading to the loss of a serine residue at position 93 was found in the SEG/Pas Wap gene. SNP frequencies found in three milk protein-encoding genes between Mus spretus and Mus musculus is twice the values previously reported at the whole genome level. However, the protein structure and post-translational modifications seem not to be affected by SNPs characterized in our study. Splicing mechanisms (cryptic splice site usage, exon skipping, error-prone junction sequence), already identified in casein genes from other species, likely explain the existence of multiple αs1-casein isoforms both in SEG/Pas and C57BL/6J strains. Finally, we propose a possible mechanism by which the hallmark tandem duplication of a 18-nt exon (14 copies) may have occurred in the mouse genome.BMC Genomics 01/2011; 12:80. · 4.07 Impact Factor -
Article: Identification of internal control genes for quantitative expression analysis by real-time PCR in bovine peripheral lymphocytes.
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ABSTRACT: Gene expression studies in blood cells, particularly lymphocytes, are useful for monitoring potential exposure to toxicants or environmental pollutants in humans and livestock species. Quantitative PCR is the method of choice for obtaining accurate quantification of mRNA transcripts although variations in the amount of starting material, enzymatic efficiency, and the presence of inhibitors can lead to evaluation errors. As a result, normalization of data is of crucial importance. The most common approach is the use of endogenous reference genes as an internal control, whose expression should ideally not vary among individuals and under different experimental conditions. The accurate selection of reference genes is therefore an important step in interpreting quantitative PCR studies. Since no systematic investigation in bovine lymphocytes has been performed, the aim of the present study was to assess the expression stability of seven candidate reference genes in circulating lymphocytes collected from 15 dairy cows. Following the characterization by flow cytometric analysis of the cell populations obtained from blood through a density gradient procedure, three popular softwares were used to evaluate the gene expression data. The results showed that two genes are sufficient for normalization of quantitative PCR studies in cattle lymphocytes and that YWAHZ, S24 and PPIA are the most stable genes.The Veterinary Journal 12/2010; 189(3):278-83. · 2.24 Impact Factor
