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101.
Lefrançois LH Pujol C Bodier CC Teixeira-Gomez AP Drobecq H Rosso ML Raze D Dias AA Hugot JP Chacon O Barletta RG Locht C Vidal Pessolani MC Biet F 《Microbes and infection / Institut Pasteur》2011,13(6):585-594
Mycobacterium avium subsp. paratuberculosis (Map) causes a chronic enteric disease in ruminants, called paratuberculosis or Johne's disease. The current model proposes that after ingestion by the host, Map crosses the intestinal barrier via internalization by the M cells. Experimental observations suggest, however, that Map may also transcytose the intestinal wall via the enterocytes, but the mechanisms involved in this process remain poorly understood. Cytoadherence assays performed on epithelial cells with Map revealed that the addition of laminin to the cell culture increases adhesion. A Map protein was isolated by heparin-Sepharose chromatography and identified as a laminin-binding protein like. The gene encoding this protein named Lbp/Hlp was identified in the Map genome sequence at locus MAP3024 (annotated Hup B). The deduced Map Lbp/Hlp amino acid sequence reveals 80% identity with that reported for other mycobacteria. The C-terminal domain involved in adhesion is mainly composed of arginine and lysine residues modified by methylation. In vitro tests demonstrated that recombinant Lbp/Hlp binds laminin, heparin, collagen and epithelial cells. Interestingly, we found that this adhesin corresponds to the antigen described as the target of pANCA and serum antibodies of patients with Crohn's disease. 相似文献
102.
Marie Billaud Diana Dahan Roger Marthan Jean-Pierre Savineau Christelle Guibert 《Respiratory research》2011,12(1):30
Background
Pulmonary hypertension (PH) is characterized by arterial vascular remodelling and alteration in vascular reactivity. Since gap junctions are formed with proteins named connexins (Cx) and contribute to vasoreactivity, we investigated both expression and role of Cx in the pulmonary arterial vasoreactivity in two rat models of PH.Methods
Intrapulmonary arteries (IPA) were isolated from normoxic rats (N), rats exposed to chronic hypoxia (CH) or treated with monocrotaline (MCT). RT-PCR, Western Blot and immunofluorescent labelling were used to study the Cx expression. The role of Cx in arterial reactivity was assessed by using isometric contraction and specific gap junction blockers. Contractile responses were induced by agonists already known to be involved in PH, namely serotonin, endothelin-1 and phenylephrine.Results
Cx 37, 40 and 43 were expressed in all rat models and Cx43 was increased in CH rats. In IPA from N rats only, the contraction to serotonin was decreased after treatment with 37-43Gap27, a specific Cx-mimetic peptide blocker of Cx 37 and 43. The contraction to endothelin-1 was unchanged after incubation with 40Gap27 (a specific blocker of Cx 40) or 37-43Gap27 in N, CH and MCT rats. In contrast, the contraction to phenylephrine was decreased by 40Gap27 or 37-43Gap27 in CH and MCT rats. Moreover, the contractile sensitivity to high potassium solutions was increased in CH rats and this hypersensitivity was reversed following 37-43Gap27 incubation.Conclusion
Altogether, Cx 37, 40 and 43 are differently expressed and involved in the vasoreactivity to various stimuli in IPA from different rat models. These data may help to understand alterations of pulmonary arterial reactivity observed in PH and to improve the development of innovative therapies according to PH aetiology. 相似文献103.
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107.
Christelle Guédot Theresa L. Pitts-Singer James S. Buckner Jordi Bosch William P. Kemp 《Physiological Entomology》2006,31(2):110-119
Abstract. The use of olfactory cues for nest recognition by the solitary bee Osmia lignaria is studied in a greenhouse environment. Glass tubes are provided as nesting cavities to allow the in-nest behaviour of bees to be observed. In addition, each glass tube is cut into three sections for experimental manipulation and for subsequent chemical analysis. Nesting females drag their abdomen along the tube before exiting, spiral inside the tube, and sometimes deposit fluid droplets from the tip of the abdomen. For the manipulation, the outer section, the middle section, or both sections are removed and replaced with similar clean glass tube sections, and the behaviour exhibited by test females is recorded upon arrival in front of the nesting site and inside the nesting tubes. The resulting hesitation behaviour displayed by females after treatments appears to indicate the loss of some olfactory cues used for nest recognition inside the entire nest. Chemical analysis of the depositions inside the nesting tube, as well as analysis of the cuticular lipids of the nesting bees, reveals the presence of free fatty acids, hydrocarbons and wax esters. 相似文献
108.
Stable transmission of targeted gene modification using single-stranded oligonucleotides with flanking LNAs 总被引:2,自引:1,他引:1 下载免费PDF全文
Andrieu-Soler C Casas M Faussat AM Gandolphe C Doat M Tempé D Giovannangeli C Behar-Cohen F Concordet JP 《Nucleic acids research》2005,33(12):3733-3742
Targeted mutagenesis directed by oligonucleotides (ONs) is a promising method for manipulating the genome in higher eukaryotes. In this study, we have compared gene editing by different ONs on two new target sequences, the eBFP and the rd1 mutant photoreceptor βPDE cDNAs, which were integrated as single copy transgenes at the same genomic site in 293T cells. Interestingly, antisense ONs were superior to sense ONs for one target only, showing that target sequence can by itself impart strand-bias in gene editing. The most efficient ONs were short 25 nt ONs with flanking locked nucleic acids (LNAs), a chemistry that had only been tested for targeted nucleotide mutagenesis in yeast, and 25 nt ONs with phosphorothioate linkages. We showed that LNA-modified ONs mediate dose-dependent target modification and analyzed the importance of LNA position and content. Importantly, when using ONs with flanking LNAs, targeted gene modification was stably transmitted during cell division, which allowed reliable cloning of modified cells, a feature essential for further applications in functional genomics and gene therapy. Finally, we showed that ONs with flanking LNAs aimed at correcting the rd1 stop mutation could promote survival of photoreceptors in retinas of rd1 mutant mice, suggesting that they are also active in vivo. 相似文献
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Pelletier JP Boileau C Boily M Brunet J Mineau F Geng C Reboul P Laufer S Lajeunesse D Martel-Pelletier J 《Arthritis research & therapy》2005,7(5):R1091-R1102
This study sought to evaluate the levels of mRNA expression and protein synthesis of MMP-13, cathepsin K, aggrecanase-1 (ADAMTS-4),
aggrecanase-2 (ADAMTS-5) and 5-lipoxygenase (5-LOX) in cartilage in the experimental anterior cruciate ligament (ACL) dog
model of osteoarthritis (OA), and to examine the effects of treatment with licofelone, a 5-lipoxygenase (LOX)/cyclooxygenase
(COX) inhibitor, on the levels of these catabolic factors. Sectioning of the ACL of the right knee was performed in three
experimental groups: group 1 received no active treatment (placebo group); and groups 2 and 3 received therapeutic concentrations
of licofelone (2.5 or 5.0 mg/kg/day orally, respectively) for 8 weeks, beginning the day following surgery. A fourth group
consisted of untreated dogs that were used as normal controls. Specimens of cartilage were selected from lesional areas of
OA femoral condyles and tibial plateaus, and were processed for real-time quantitative PCR and immunohistochemical analyses.
The levels of MMP-13, cathepsin K, ADAMTS-4, ADAMTS-5 and 5-LOX were found to be significantly increased in OA cartilage.
Licofelone treatment decreased the levels of both mRNA expression and protein synthesis of the factors studied. Of note was
the marked reduction in the level of 5-LOX gene expression. The effects of the drug were about the same at both tested dosages.
In vivo treatment with therapeutic dosages of licofelone has been found to reduce the degradation of OA cartilage in experimental
OA. This, coupled with the results of the present study, indicates that the effects of licofelone are mediated by the inhibition
of the major cartilage catabolic pathways involved in the destruction of cartilage matrix macromolecules. Moreover, our findings
also indicate the possible auto-regulation of 5-LOX gene expression by licofelone in OA cartilage. 相似文献