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Communication between leukocytes and endothelial cells is crucial for inflammatory reactions. Paracrine cross-talk and outside-in signaling (via adhesion molecules) have been characterized as communication pathways to date. As leukocytes and endothelial cells express connexins, we considered intercellular communication via gap junctions an intriguing additional concept. We found that gap-junctional coupling between neutrophils and endothelium occurred in a time-dependent, bidirectional manner and was facilitated by adhesion. After blockade of connexins, transmigration of neutrophils through the endothelial layer was enhanced, and the barrier function of cell monolayers was reduced during transmigration. Tumor necrosis factor alpha decreased coupling. In the presence of connexins, transmigration of neutrophils did not alter permeability. Thus, neutrophils couple to endothelium via gap junctions, functionally modulating transmigration and leakiness. Gap-junctional coupling may be a novel way of leukocyte-endothelial communication. 相似文献
14.
Meissner W Harnack D Paul G Reum T Sohr R Morgenstern R Kupsch A 《Neuroscience letters》2002,323(2):105-108
Recent studies have reported a genetic association between the -1438 G/A polymorphism within the promoter region of the 5-HT(2A) receptor gene and eating disorders (ED), with conflicting results. To clarify the role of the -1438 G/A polymorphism in different ED categories we have analyzed the genotype and allele frequency distribution in 54 Italian patients with Binge ED (BED) compared to 132 obese non-BED subjects. No significant differences were found between obese BED and obese non-BED individuals, suggesting that this polymorphism does not genetically distinguish these two phenotypes. Moreover, the evaluation of 148 patients with anorexia nervosa and 86 patients with bulimia nervosa revealed an association of the A allele with both these disorders. 相似文献
15.
Phosphatidylcholine-Specific Phospholipase C from Listeria monocytogenes Is an Important Virulence Factor in Murine Cerebral Listeriosis 总被引:1,自引:0,他引:1 下载免费PDF全文
Dirk Schlüter Eugen Domann Christine Buck Torsten Hain Herbert Hof Trinad Chakraborty Martina Deckert-Schlüter 《Infection and immunity》1998,66(12):5930-5938
Meningoencephalitis is a serious and often fatal complication of Listeria monocytogenes infection. The aim of the present study was to analyze the role of internalin A (InlA) and B, which are involved in the invasion of L. monocytogenes into cultivated host tissue cells, and that of phosphatidylcholine-specific phospholipase C (PlcB), which mainly promotes the direct cell-to-cell spread of L. monocytogenes, in murine cerebral listeriosis by use of an InlA/B (ΔinlAB2)- and a PlcB (ΔplcB2)-deficient isogenic deletion mutant strain and the wild-type (WT) L. monocytogenes EGD. Listeria strains were directly applied to the brain, a technique which has been employed previously to study the pathogenesis of cerebral listeriosis (D. Schlüter, S. B. Oprisiu, S. Chahoud, D. Weiner, O. D. Wiestler, H. Hof, and M. Deckert-Schlüter, Eur. J. Immunol. 25:2384–2391, 1995). We demonstrated that PlcB, but not InlA or InlB, is an important virulence factor in cerebral listeriosis. Nonimmunized mice infected intracerebrally with the ΔplcB2 strain survived significantly longer and had a reduced intracerebral bacterial load compared to mice infected with the ΔinlAB2 strain or WT bacteria. In addition, immunization with the WT prior to intracerebral infection significantly increased the survival rate of mice challenged intracerebrally with the ΔplcB2 strain compared to that of mice infected with the WT or ΔinlAB2 strain. Histopathology revealed that the major difference between the various experimental groups was a significantly delayed intracerebral spread of the ΔplcB2 mutant strain, indicating that cell-to-cell spread is an important pathogenic feature of cerebral listeriosis. Interestingly, irrespective of the Listeria mutant used, the apoptosis of hippocampal and cerebellar neurons and an internal hydrocephalus developed in surviving mice, indicating that these complications are not dependent on the virulence factors InlA/B and PlcB. In conclusion, this study points to PlcB as a virulence factor important for the intracerebral pathogenesis of murine L. monocytogenes meningoencephalitis. 相似文献
16.
Gene expression patterns and gene copy number changes in dermatofibrosarcoma protuberans 总被引:5,自引:0,他引:5 下载免费PDF全文
Linn SC West RB Pollack JR Zhu S Hernandez-Boussard T Nielsen TO Rubin BP Patel R Goldblum JR Siegmund D Botstein D Brown PO Gilks CB van de Rijn M 《The American journal of pathology》2003,163(6):2383-2395
Dermatofibrosarcoma protuberans (DFSP) is an aggressive spindle cell neoplasm. It is associated with the chromosomal translocation, t(17:22), which fuses the COL1A1 and PDGFbeta genes. We determined the characteristic gene expression profile of DFSP and characterized DNA copy number changes in DFSP by array-based comparative genomic hybridization (array CGH). Fresh frozen and formalin-fixed, paraffin-embedded samples of DFSP were analyzed by array CGH (four cases) and DNA microarray analysis of global gene expression (nine cases). The nine DFSPs were readily distinguished from 27 other diverse soft tissue tumors based on their gene expression patterns. Genes characteristically expressed in the DFSPs included PDGF beta and its receptor, PDGFRB, APOD, MEOX1, PLA2R, and PRKCA. Array CGH of DNA extracted either from frozen tumor samples or from paraffin blocks yielded equivalent results. Large areas of chromosomes 17q and 22q, bounded by COL1A1 and PDGF beta, respectively, were amplified in DFSP. Expression of genes in the amplified regions was significantly elevated. Our data shows that: 1) DFSP has a distinctive gene expression profile; 2) array CGH can be applied successfully to frozen or formalin-fixed, paraffin-embedded tumor samples; 3) a characteristic amplification of sequences from chromosomes 17q and 22q, demarcated by the COL1A1 and PDGF beta genes, respectively, was associated with elevated expression of the amplified genes. 相似文献
17.
Mesenteric lymph nodes are critical for the induction of high-dose oral tolerance in the absence of Peyer's patches 总被引:7,自引:0,他引:7
Spahn TW Weiner HL Rennert PD Lügering N Fontana A Domschke W Kucharzik T 《European journal of immunology》2002,32(4):1109-1113
We have previously demonstrated the loss of oral tolerance (OT) in lymphotoxinalpha-/- (LTalpha-/-) and TNFalpha / lymphotoxinalpha deficient (TNFalpha / LTalpha-/-) mice which have defective Peyer's patches (PP) and lymph node (LN) development. We have now studied OT in BALB / c mice with differential defects of the gut-associated lymphoid tissue (GALT) caused by inhibition of LTbetaR signaling during fetal development. Treatment of pregnant mice with LTbetaR-IgG (LTbetaRIgG) and TNFR I55-IgG (TNFR55IgG) abrogates the formation of PP (LTbetaRIgG) or of PP and mesenteric LN (MLN) (LTbetaRIgG / TNFRIgG) without genetically deleting the respective cytokine pathways. OT was readily induced in mice without PP but retaining MLN (PP null / LN +). In contrast, OTcould not be induced in mice lacking both MLN and PP (PP null / MLN null) as shown by the inability of these mice to suppress IFN-gamma secretion or DTH reactions. We next assessed OT in 129 x B6 LTalpha-/- mice with and without MLN. Timed treatment of pregnant LTalpha-/- mice with an agonist anti-LTbetaR mAb induces formation of MLN but not of PP in LTalpha-/- mice. LN + LTalpha-/- mice developed OT while LN LTalpha-/- mice were resistant to OT induction. Taken collectively, the data show that in the presence of MLN PP are not required for OT induction and that the presence of MLN is sufficient for OT induction in the LTalpha-/- model. 相似文献
18.
Fischbach C Seufert J Staiger H Hacker M Neubauer M Göpferich A Blunk T 《Tissue engineering》2004,10(1-2):215-229
In vivo and in vitro studies have demonstrated both promise and current limitations in tissue engineering of fat. Herein, we report the establishment of a well-defined three-dimensional (3-D) in vitro model useful for systematic investigations of 3-D adipogenesis. Polyglycolic acid fiber meshes were dynamically seeded with 3T3-L1 preadipocytes; subsequently, cell-polymer constructs were hormonally induced and cultivation under three different conditions was evaluated. Regarding tissue coherence and intracellular lipid content, culture of cell-polymer constructs either dynamically in well plates or in stirred bioreactors yielded similar results, which were distinctly improved compared with static conditions in well plates. At the protein and mRNA levels, significantly increased expression of genes characteristic for a mature adipose phenotype was demonstrated for constructs dynamically cultured in well plates, as compared with static conditions. Furthermore, investigation of lipolysis under stimulating and inhibiting conditions demonstrated functionality of the dynamically differentiated constructs. Using dynamic culture conditions, the presented in vitro model system is suggested as a valuable tool serving both fat tissue engineering and basic research by facilitating investigations of tissue-inherent features not possible under conventional 2-D culture conditions. 相似文献
19.
Hocher B Dembowski C Slowinski T Friese ST Schwarz A Siren AL Neumayer HH Thöne-Reineke C Bauer C Nafz B Ehrenreich H 《Journal of molecular medicine (Berlin, Germany)》2001,78(11):633-641
The renal endothelin (ET) system, particularly the ET type B receptor, has been implicated in the regulation of sodium excretion and glomerular filtration rate (GFR). We analyzed kidney morphology and function in a rat strain characterized by complete absence of a functional ETB receptor. Due to Hirschsprung's disease limiting lifetime in these rats, studies were performed in 23-day-old rats. Kidney size and morphology (glomerular and interstitial matrix content, glomerular size and cell density and intrarenal vascular morphology) were normal in ETB-deficient rats. There were also no evidence of altered kidney cell cycle regulation in these rats. GFR was significantly lower, by 72% (P<0.001), in homozygous ETB-deficient rats than in wild-type rats. Fractional sodium excretion was likewise markedly reduced by 84% in homozygous ETB-deficient rats (P<0.001 versus wild-type rats). Treatment with the specific epithelial sodium channel blocker amiloride led to a much higher increase in fractional sodium excretion in ETB-deficient rats (934.2+/-73% in ETB-deficient rats versus 297+/-20% in wild-type rats, expressed as percentage of corresponding placebo treated control; P<0.001). Mean arterial blood pressure was elevated by 7.9 mmHg in homozygous ETB-deficient rats (P<0.05 versus wild-type rats). Our study demonstrates that ETB-deficiency causes early onset kidney dysfunction characterized by a markedly reduced sodium excretion, decreased GFR, and slightly elevated blood pressure. The complete absence of the ETB receptor causes in the kidney--in contrast to the colon--a functional rather than a developmental, neural crest cell dependent disease, since kidney morphology was normal in ETB-deficient rats. The much higher increase in the fractional sodium excretion in ETB-deficient rats after pharmacological blockade of the epithelial sodium channel indicates that the decreased fractional sodium excretion in ETB-deficient rats is most probably due to a lack of the inhibitory property of the ETB receptor on the epithelial sodium channel activity. 相似文献
20.
Summary An outbreak of aseptic meningitis in association with ECHO virus type 4 is described. This virus was isolated in 8 out of 12 cases with this syndrome from stool specimens and in two cases also from spinal fluids and furthermore from healthy family contacts. Neutralizing antibodies in the patients sera could not be demonstrated with the conventional tube tests while complement fixing antibodies with increasing titer against ECHO-4 occurred. There is an extensive heterotypic complement fixing antibody response in patients sera within the ECHO virus group between this group and the Coxsackie or the poliomyelitis group as well as beetwen the Coxsackie and the poliomyelitis groups.The choice of tissue for isolation of enteroviruses is discussed. Trypsinized human embryonic kidney seems to provide a suitable medium for this group of viruses.A rubella-like exanthem was seen in about two thirds of the virus positive patients. Some cases had diphasic course. 相似文献