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F Blasi

Publications and source records attributed to F Blasi.

At least 73 records · Page 4Linked to original sources
PubMed2000

Chlamydia pneumoniae detection in atherosclerotic plaques in Italy.

Italian investigations have shown an association between Chlamydia pneumoniae infection and atherosclerosis. With the use of several diagnostic techniques, including serology, a microimmunofluorescence test, and nucleic acid amplification methods, a temporal association was found between acute C. pneumoniae reinfection and acute myocardial infarction, suggesting that an acute infection superimposed on a chronic or latent infection may trigger the onset of acute myocardial infarction. C. pneumoniae but not Helicobacter pylori or Mycoplasma pneumoniae was found in atherosclerotic plaques of abdominal aortic aneurysms and the carotid artery. A reverse transcriptase-polymerase chain reaction process confirmed the presence of viable C. pneumoniae in carotid atheromas. Nucleic amplification of peripheral blood mononuclear cells may enable the identification of subjects carrying C. pneumoniae in the vascular wall. Macrolide treatment reduced fibrinogen and C-reactive protein plasma levels and C. pneumoniae burden in patients with atherosclerotic diseases.

Adult↗
PubMed2000

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Journal Article↗
PubMed2000

Automated, PCR-RFLP genotyping of the urokinase gene.

The urokinase-type plasminogen activator (u-PA) has been suggested to play a role in the early initiation and progression of atherosclerosis and coronary artery disease (CAD) (Grenett et aL, 1998). Recently, a common genetic polymorphism in the untranslated region of the u-PA gene was shown to be associated with syptomatic CAD. To study the possible role of this common genetic polymorphism in the u-PA gene, we have developed an automated, PCR-based assay. Automation of the PCR-RFLP genotyping of the BamHI polymorphism of the urokinase gene will support the screening of the large sample sizes required to do the population-based studies necessary to uncover disease susceptibility associations.

Automation↗
PubMed2000

Immunohistochemical staining for Chlamydia pneumoniae is increased in lung tissue from subjects with chronic obstructive pulmonary disease.

The seroprevalence of Chlamydia pneumoniae is increased in chronic obstructive pulmonary disease (COPD), and subjects with COPD are more likely to have a positive polymerase chain reaction for C. pneumoniae in their sputum. It has been suggested that C. pneumoniae may have a role in the pathogenesis of COPD. We undertook immunohistochemistical staining for C. pneumoniae in archival tissue from subjects who had undergone lobectomy for bronchial carcinoma. There were 16 subjects with COPD (FEV(1) = 64 +/- 8% [mean +/- SD] predicted) and 21 subjects with normal lung function (FEV(1) = 95 +/- 11% predicted). There was no difference between the two groups in age or smoking history. Tissues from all of the subjects stained positively for C. pneumoniae, but in the subjects with COPD there were 14.5 positive cells per field (magnification x400), as compared with 9.3 cells per field in the control subjects (p = 0.02). Fifty-four percent of the macrophages from the subjects with COPD stained positively for C. pneumoniae, as compared with 29% from the control subjects (p < 0.001). A second control group consisted of 18 younger individuals (mean age: 32 yr) who died accidentally. Only 44% of these subjects had positive staining for C. pneumoniae, and the mean number of cells per field was 0.4. These findings suggest that persistent infection with C. pneumoniae is common, and that there is increased immunostaining for C. pneumoniae in COPD. Further studies are necessary to determine whether chronic infection with C. pneumoniae is important in the pathogenesis of COPD.

Adult↗
PubMed2000

Segmental expression of Hoxb2 in r4 requires two separate sites that integrate cooperative interactions between Prep1, Pbx and Hox proteins.

Direct auto- and cross-regulatory interactions between Hox genes serve to establish and maintain segmentally restricted patterns in the developing hindbrain. Rhombomere r4-specific expression of both Hoxb1 and Hoxb2 depends upon bipartite cis Hox response elements for the group 1 paralogous proteins, Hoxal and Hoxbl. The DNA-binding ability and selectivity of these proteins depend upon the formation of specific heterodimeric complexes with members of the PBC homeodomain protein family (Pbx genes). The r4 enhancers from Hoxb1 and Hoxb2 have the same activity, but differ with respect to the number and organisation of bipartite Pbx/Hox (PH) sites required, suggesting the intervention of other components/sequences. We report here that another family of homeodomain proteins (TALE, Three-Amino acids-Loop-Extension: Prep1, Meis, HTH), capable of dimerizing with Pbx/EXD, is involved in the mechanisms of r4-restricted expression. We show that: (1) the r4-specific Hoxb1 and Hoxb2 enhancers are complex elements containing separate PH and Prep/Meis (PM) sites; (2) the PM site of the Hoxb2, but not Hoxb1, enhancer is essential in vivo for r4 expression and also influences other sites of expression; (3) both PM and PH sites are required for in vitro binding of Prepl-Pbx and formation and binding of a ternary Hoxbl-Pbxla (or 1b)-Prepl complex. (4) A similar ternary association forms in nuclear extracts from embryonal P19 cells, but only upon retinoic acid induction. This requires synthesis of Hoxbl and also contains Pbx with either Prepl or Meisl. Together these findings highlight the fact that PM sites are found in close proximity to bipartite PH motifs in several Hox responsive elements shown to be important in vivo and that such sites play an essential role in potentiating regulatory activity in combination with the PH motifs.

Animals↗
PubMed2000

Enhanced urinary gelatinase activities (matrix metalloproteinases 2 and 9) are associated with early-stage bladder carcinoma: a comparison with clinically used tumor markers.

Matrix metalloproteinases (MMPs) are involved in tumor growth and metastasis, promoting the migration and invasion of cells. In this study, the amount of MMP-2 and MMP-9 activity was measured in urine from superficial bladder carcinoma patients (pTa, pT1) to evaluate their possible diagnostic value. The active and total amount of MMP-2 and MMP-9, respectively, in urine from tumor patients were compared with the levels in urine from age- and gender-matched healthy volunteers. Both MMP-2 and MMP-9 activity levels were significantly enhanced in urine from patients with high invasive cancers (pT2, PT3), whereas in urine from healthy controls no or very low MMP activities were found. More importantly, a substantial number of urine samples from patients with superficial tumors contained elevated MMP-2 and MMP-9 activities, suggesting that enhanced urinary MMP activity levels, indeed, might be indicative for early-stage bladder cancer. Overall, urinary MMP-2 and MMP-9 activity levels were significantly correlated to each other, with some individual exceptions. A comparison between urinary MMP-9 activity and a recently proposed urinary marker for bladder cancer, NMP-22, showed slightly lower numbers of patients with elevated levels for MMP-9. But because MMP-9 and NMP-22 levels were not correlated, enhanced urinary MMP activity might be useful as a marker for superficial bladder carcinoma like, or especially in combination with, other markers.

Adult↗
PubMed2000

Temporal arteritis associated with Chlamydia pneumoniae DNA detected in an artery specimen.

Temporal arteritis is a clinical manifestation of giant cell arteritis. The etiology of this disease is still unknown. Sudden onset and wide variations of incidence are reported in different parts of the world. Acute onset is often associated with flu-like symptoms, indicating that infectious factors probably act as precipitating agents. We describe a 72-year-old man referred to our department in January 1999 for unremitting fever and temporal arteritis associated with Chlamydia pneumoniae infection.

Aged↗
PubMed1999

Src-dependence and pertussis-toxin sensitivity of urokinase receptor-dependent chemotaxis and cytoskeleton reorganization in rat smooth muscle cells.

The catalytically inactive precursor of urokinase-type plasminogen activator (pro-u-PA) induced a chemotactic response in rat smooth muscle cells (RSMC) through binding to the membrane receptor of urokinase (u-PA receptor [u-PAR]). A soluble form of u-PAR activated by chymotrypsin cleavage as well as a peptide located between domain 1 and 2 of u-PAR reproduced the effect of pro-u-PA on cell migration. The chemotactic pro-u-PA effect correlates with a dramatic reorganization of actin cytoskeleton, of adhesion plaques, and with major cell shape changes in RSMC. Pro-u-PA induced a decrease in stress fiber content, membrane ruffling, actin ring formation, and disruption leading to the characteristic elongated cell shape of motile cells with an actin semi-ring located close to the leading edge of cells. u-PAR effects on both chemotaxis and cytoskeleton were sensitive to pertussis toxin and, hence, possibly require G proteins. u-PAR effects are accompanied by a relocation of u-PAR, vitronectin receptor (VNR) alphavbeta3, beta1 integrin subunit, and Src tyrosine kinase to the leading membrane of migrating cells. In conclusion, our data show that pro-u-PA, via binding to u-PAR, controls a signaling pathway, regulated by tyrosine kinases and possibly G proteins, leading to cell cytoskeleton reorganization and cell migration.

Actins↗
PubMed1999

In vivo inhibition of NF-kappa B in T-lineage cells leads to a dramatic decrease in cell proliferation and cytokine production and to increased cell apoptosis in response to mitogenic stimuli, but not to abnormal thymopoiesis.

To understand the role of NF-kappa B complexes in T cell development and activation, we have generated transgenic mice in which RelA and c-Rel complexes were selectively inhibited in the T-lineage cells by specific expression of a trans-dominant form of I kappa B alpha. Transgene expression did not affect the thymic development, but led to lowered numbers of splenic T cells and to a dramatic decrease in the ex vivo proliferative response of splenic T lymphocytes. Analysis of IL-2 and IL-2R alpha expression demonstrated that the perturbation of the proliferation response was not attributable to an abnormal expression of these genes. In contrast, expression of IL-4, IL-10, and IFN-gamma was strongly inhibited in the transgenic T cells. The proliferative deficiency of the transgenic T cells was associated with an increased apoptosis. These results point out the involvement of NF-kappa B/Rel family proteins in growth signaling pathways by either regulating proteins involved in the IL-2 signaling or by functionally interfering with the cell cycle progression.

Animals↗
PubMed1999

In vivo analysis of the state of the human uPA enhancer following stimulation by TPA.

We have analysed in vivo the -2.0 kb enhancer of the human urokinase-type plasminogen activator (uPA) gene in HepG2 cells, in which gene expression can be induced by phorbol esters. The results reveal that, within the regulatory region, the enhancer, the silencer and the minimal promoter become hypersensitive to deoxyribonuclease I (DNase I) upon induction of transcription. The hypersensitivity of the enhancer can be reversed after removal of the inducer. In vivo footprinting analysis indicates that all the cis-acting elements of the enhancer, previously identified in vitro, are occupied in vivo upon 12-O-tetradecanoyl-phorbol-13-acetate (TPA) stimulation of HepG2 cells. Micrococcal nuclease (MNase) cleavage of this region fails to reveal discrete nucleosomal boundaries in vivo in close proximity of the enhancer, either before or after stimulation. Furthermore, this region does not lose its nucleosomal configuration after TPA induction of transcription. An approximately 600 bp long region around the enhancer becomes more, but not fully, accessible to restriction endonucleases upon stimulation. A time-course experiment shows that this accessibility reaches a plateau after a 1 h TPA treatment suggesting the persistent presence of nucleosomes. These results indicate that TPA induces the binding of transcription factors to the uPA enhancer without chromatin remodelling of this region.

Binding Sites↗
PubMed1999

The subcellular localization of PBX1 and EXD proteins depends on nuclear import and export signals and is modulated by association with PREP1 and HTH.

Nuclear localization of the Extradenticle (EXD) and PBX1 proteins is regionally restricted during Drosophila and mammalian development. We studied the subcellular localization of EXD, PBX, and their partners Homothorax (HTH) and PREP1, in different cell contexts. HTH and PREP1 are cytoplasmic and require association with EXD/PBX for nuclear localization. EXD and PBX1 are nuclear in murine fibroblasts but not in Drosophila Schneider cells, in which they are actively exported to the cytoplasm. Coexpression of EXD/PBX with HTH/PREP1 causes nuclear localization of their heterodimers in both cell contexts. We propose that heterodimerization with HTH/PREP induces nuclear translocation of EXD and PBX1 in specific cell contexts by blocking their nuclear export.

3T3 Cells↗
PubMed1999

Treatment of Helicobacter pylori and Chlamydia pneumoniae infections decreases fibrinogen plasma level in patients with ischemic heart disease.

BACKGROUND: Chronic Chlamydia pneumoniae and Helicobacter pylori infections could be a risk factor for ischemic heart disease (IHD), possibly by increasing fibrinogen levels. The aim of our study was to evaluate changes in fibrinogen level in patients with IHD and H pylori and/or C pneumoniae positivity randomly assigned to antibiotic treatment. METHODS AND RESULTS: Eighty-four patients with chronic IHD, H pylori and/or C pneumoniae antibodies, and normal acute-phase reactants were randomly assigned to treatment or no treatment. Treatment consisted of omeprazole, clarithromycin, and tinidazole in H pylori-positive patients and clarithromycin alone in C pneumoniae-positive patients. The effect of treatment and other baseline variables on fibrinogen levels, determined at 6 months, was evaluated by multivariate analysis. Treatment significantly reduced fibrinogen level at 6 months in the overall study population and in the groups of patients divided according to H pylori or C pneumoniae positivity. In the 43 treated patients, mean (+/-SD) basal fibrinogen was 3.65+/-0.58 g/L, and mean final fibrinogen was 3. 09+/-0.52 g/dL (P<0.001), whereas in the 41 untreated patients, mean basal and final fibrinogen levels were 3.45+/-0.70 and 3.61+/-0.71 g/L, respectively. The largest decrease was observed in patients with both infections. Fibrinogen changes were also significantly and negatively correlated with age. CONCLUSIONS: Our data suggest that a short, safe, and effective course of antibiotic therapy might be suggested as a means of interacting with an "emerging" risk factor.

Anti-Bacterial Agents↗
PubMed1999

Expression of matrix metalloproteinases during murine chorioallantoic placenta maturation.

A large body of experimental evidence supports the participation of two groups of extracellular proteases, matrix metalloproteinases (MMPs), and plasminogen activators/plasmin, in tissue remodeling in physiological and pathological invasion. In the late mouse placenta, several tissue remodeling and cell invasion processes take place. Spongiotrophoblast migration into maternal decidua, as well as decidual extracellular matrix remodeling require the coordinated action of extracellular proteolytic enzymes. Via Northern and in situ hybridization, we have analyzed the spatio-temporal expression patterns of members of the MMP family (stromelysin-3, gelatinases A and B), as well as their inhibitors TIMP-1, -2 and -3 in late murine placenta (days 10.5 to 18.5 of gestation). Gelatinase activity in placental extracts was assessed by substrate zymography. Gelatinase A and stromelysin-3 were found to be prominently expressed in decidual tissue; shortly after midpregnancy, the decidual expression patterns of gelatinase A and stromelysin-3 became overlapping with each other, as well as with the expression domain of TIMP-2. On the other hand, gelatinase B transcripts were expressed only by trophoblast giant cells at day 10.5, and were downregulated at later stages. TIMP-1 and TIMP-3 transcripts were detected in decidual periphery at day 10.5, while later the expression was restricted to the endometrial stroma and spongiotrophoblasts, respectively. The areas of stromelysin-3 expression were the same (giant trophoblasts) or adjacent (decidua) to those where urokinase (uPA) transcripts were detected, suggesting a possible cooperation between these proteinases in placental remodeling. We generated mice doubly deficient for stromelysin-3 and uPA, and report here that these mice are viable and fertile. Furthermore, these animals do not manifest obvious placental abnormalities, thereby suggesting the existence of compensatory/redundant mechanisms involving other proteolytic enzymes. Our findings document the participation of MMPs and their inhibitors in the process of late murine placenta maturation, and warrant the characterization of other members of the MMP family, like membrane type-MMPs, in this process.

Allantoin↗
PubMed1999

Trophoblast giant cells express NF-kappa B2 during early mouse development.

To investigate whether transcription factors of the NF-kappa B family could play a role in early mammalian development, we have analyzed the expression of nfkb1, nfkb2, c-Rel, RelA, RelB, and bcl-3 from 6.5- to 10.5-day mouse embryo implantation sites. Our study shows that nfkb2 mRNA and protein are specifically localized in trophoblast giant cells throughout the stages analyzed. Trophoblast giant cells obtained upon in vitro cultures of 7.5-day ectoplacental cones display NF-kappa B DNA-binding activity that is supershifted by the anti-NF-kappa B2 antibody. Trophoblast giant cells are embryo-derived cells that form an interface between embryonic and maternal tissues during early mouse development; they are involved in decidual remodeling and expansion of the embryonic cavity, placenta formation, and possibly avoidance of maternal immune response to the embryo. Our study suggests that NF-kappa B2 could play a role in the modulation of genes expressed in trophoblast giant cells during the course of early embryogenesis, and therefore be relevant for tissue remodeling and morphogenesis of placenta.

Animals↗
PubMed1999

Demonstration of viable Chlamydia pneumoniae in atherosclerotic plaques of carotid arteries by reverse transcriptase polymerase chain reaction.

The presence of Chlamydia pneumoniae in atheromas has been demonstrated in several studies. Culture of the organism from arterial tissue has been difficult. We report the use of a reverse transcriptase polymerase chain reaction to detect viable Chlamydia pneumoniae in carotid atheromas. We analyzed 30 patients (14 females, mean age 69.6 +/- 8.8 years) who underwent surgery for the removal of atherosclerotic plaques from carotid arteries. During surgery, samples of lingual vein and superior thyroideal artery were also taken. We applied two molecular biology techniques to the carotid plaques on lingual vein or thyroideal artery samples: 1) polymerase chain reaction (PCR) and 2) reverse transcriptase-PCR (RT-PCR) for the detection of bacterial mRNA, employing PCR primers designed to detect a fragment of the 16S rRNA gene. Blood samples were obtained from the patients for determination of Chlamydia pneumoniae IgG, IgA, and IgM antibody titers by a microimmunofluorescence technique. The results of the present study confirmed the presence of viable Chlamydia pneumoniae in atheromas and support the hypothesis that the organism may be an active factor in the pathogenesis of atherosclerosis.

Aged↗
PubMed1999

The PBX-regulating protein PREP1 is present in different PBX-complexed forms in mouse.

Human PREP1, a novel homeodomain protein of the TALE super-family, forms a stable DNA-binding complex with PBX proteins in solution, a ternary complex with PBX and HOXB1 on DNA, and is able to act as a co-activator in the transcription of PBX-HOXB1 activated promoters (Berthelsen, J., Zappavigna, V., Ferretti, E., Mavilio, F., Blasi, F. , 1998b. The novel homeoprotein Prep1 modulates Pbx-Hox protein cooperatity. EMBO J. 17, 1434-1445; Berthelsen, J., Zappavigna, V., Mavilio, F., Blasi, F., 1998c. Prep1, a novel functional partner of Pbx proteins. EMBO J. 17, 1423-1433). Here we demonstrate the presence of DNA-binding PREP1-PBX complexes also in murine cells. In vivo, PREP1 is a predominant partner of PBX proteins in various murine tissues. However, the choice of PBX family member associated with PREP1 is largely tissue-type specific. We report the cloning and expression domain of murine Prep1 gene. Murine PREP1 shares 100% identity with human PREP1 in the homeodomain and 95% similarity throughout the whole protein. In the adult mouse, PREP1 is expressed ubiquitously, with peaks in testis and thymus. We further demonstrate the presence of murine Prep1 mRNA and protein, and of different DNA-binding PREP1-PBX complexes, in mouse embryos from at least 9.5 days p.c. Moreover, we show that PREP1 is present in all embryonic tissues from at least 7.5-17.5 days p.c with a predominantly nuclear staining. PREP1 is able to super-activate the PBX-HOXB-1 autoregulated Hoxb-1 promoter, and we show that all three proteins, PREP1, PBX and HOXB-1, are present together in the mouse rhombomere 4 domain in vivo, compatible with a role of PREP1 as a regulator of PBX and HOXB-1 proteins activity during development.

3T3 Cells↗