Experimentally, lung inflammation in laboratory animals is usually detected by the presence of in... more Experimentally, lung inflammation in laboratory animals is usually detected by the presence of inflammatory markers, such as immune cells and cytokines, in the bronchoalveolar lavage fluid (BALF) of sacrificed animals. This method, although extensively used, is time, money and animal life consuming, especially when applied to genetically modified animals. Thus a new and more convenient approach, based on in vivo imaging analysis, has been set up to evaluate the inflammatory response in the lung of CFTR-deficient (CF) mice, a murine model of cystic fibrosis. Wild type (WT) and CF mice were stimulated with P. aeruginosa LPS, TNF-alpha and culture supernatant derived from P. aeruginosa (strain VR1). Lung inflammation was detected by measuring bioluminescence in vivo in mice transiently transgenized with a luciferase reporter gene under the control of a bovine IL-8 gene promoter. Differences in bioluminescence (BLI) signal were revealed by comparing the two types of mice after intratrac...
Tailored nanoparticles offer a novel approach to fight antibiotic-resistant microorganisms. We an... more Tailored nanoparticles offer a novel approach to fight antibiotic-resistant microorganisms. We analysed biogenic selenium nanoparticles (SeNPs) of bacterial origin to determine their antimicrobial activity against selected pathogens in their planktonic and biofilm states. SeNPs synthesized by Gram-negative Stenotrophomonas maltophilia [Sm-SeNPs()] and Gram-positive Bacillus mycoides [Bm-SeNPs(+)] were active at low minimum inhibitory concentrations against a number of clinical isolates of Pseudomonas aeruginosa but did not inhibit clinical isolates of the yeast species Candida albicans and C. parapsilosis. However, the SeNPs were able to inhibit biofilm formation and also to disaggregate the mature glycocalyx in both P. aeruginosa and Candida spp. The Sm-SeNPs() and Bm-SeNPs(+) both achieved much stronger antimicrobial effects than synthetic selenium nanoparticles (Ch-SeNPs). Dendritic cells and fibroblasts exposed to Sm-SeNPs(), Bm-SeNPs(+) and Ch-SeNPs did not show any loss of cell viability, any increase in the release of reactive oxygen species or any significant increase in the secretion of pro-inflammatory and immunostimulatory cytokines. Biogenic SeNPs therefore appear to be reliable candidates for safe medical applications, alone or in association with traditional antibiotics, to inhibit the growth of clinical isolates of P. aeruginosa or to facilitate the penetration of P. aeruginosa and Candida spp. biofilms by antimicrobial agents.
When cystic fibrosis (CF) is suspected Nasal Potential Difference (NPD) measurements are proposed... more When cystic fibrosis (CF) is suspected Nasal Potential Difference (NPD) measurements are proposed to support controversial diagnosis: we investigated appropriate outcomes at the CF Centre of Verona. NPD were measured in 196 subjects: 50 non-CF, 65 classical CF (the reference group) and 81 with uncertain CF (case group). Discriminating power was determined by comparison between several outcomes from the CF reference group versus non-CF: basal, amiloride, 0Cl, isoproterenol, ATP, Delta-amiloride, Delta-0Cl, Delta-isoproterenol, Delta-ATP, Delta-isoproterenol+Delta-0Cl, Wilschanski Index (WI) and Sermet score (SS). The most appropriate cut-off values for variables with the best discriminating power were then applied to the case group. Descriptive statistics, logistic regression models and ROC curve analysis were applied. WI and SS were the most powerful in discriminating CF from non-CF subjects. In the reference group sensitivity of the 0.82 WI cut-off was 98%, specificity 96%; both sensitivity and specificity of the -0.44 SS cut-off value were 100%. For the case group, WI and SS were, respectively, consistent with CF diagnosis in 94% and 92% of the cases. Formulae have the highest discriminating power and can support the diagnosis in uncertain cases; they should be utilized for standardized interpretation of NPD for diagnosis and possibly for clinical research.
Pseudomonas aeruginosa is the predominant pathogen associated with the decline of pulmonary funct... more Pseudomonas aeruginosa is the predominant pathogen associated with the decline of pulmonary function in cystic fibrosis (CF) patients. Both environment-to-host acquisition and patient-to-patient transmission have been described for P. aeruginosa infection. Epidemic clones and bacterial phenotypic adaptation to the CF lung have been recognised as independent risk factors for disease progression. So far, there is no established link between genotypic prevalence and phenotypic traits. Here, we look at the major CF patient cohort in Italy to identify shared P. aeruginosa clones and associated common phenotypic traits. A comprehensive analysis of P. aeruginosa genotypes to determine the presence of high-risk shared clones and their association to specific phenotypic traits has been performed in a major Italian CF centre. Pulsed-field gel electrophoresis (PFGE) of P. aeruginosa isolates from 338 CF subjects identified 43 profiles shared by two or more patients and 214 profiles exclusive to individual patients. There was no evidence of a P. aeruginosa outbreak, but four most prevalent pulsotypes were detected. Common phenotypic traits were recorded intra-pulsotypes, but we detected heterogeneity inter-pulsotypes. Two of the four major pulsotypes included P. aeruginosa isolates with hallmarks of adaptation to the CF airways, including loss of motility, low production of siderophore, pyocyanin and proteases, and antibiotic resistance. One of these pulsotypes grouped a high percentage of hypermutable isolates. No clear correlation between epidemiological and clinical data was found. We conclude that CF patients of this cohort shared common pulsotypes, but their phenotypic heterogeneity indicates an absence of specific traits associated to P. aeruginosa genotypic prevalence.
Deregulated immune response fails to control biofilm-forming bacteria, as Pseudomonas aeruginosa,... more Deregulated immune response fails to control biofilm-forming bacteria, as Pseudomonas aeruginosa, in the lungs of cystic fibrosis (CF) patients. HLA-G is an immune-modulatory molecule involved in respiratory diseases and infections. HLA-G mRNA and protein were analyzed in plasma and exhaled breath condensate from CF patients undergoing intravenous antibiotic treatment, CF cell line and murine model. Therapy normalizes HLA-G plasmatic in CF patients suggesting a systemic anti-inflammatory role while in CF airway system, higher expression of HLA-G is associated with P. aeruginosa infection. CF cell line and murine model expressed higher HLA-G molecules in the presence of P. aeruginosa. Plasmatic and lung HLA-G expression suggest a role in reducing systemic inflammation and supporting P. aeruginosa infection.
American Journal of Respiratory and Critical Care Medicine, 2015
Cystic fibrosis (CF) is a common genetic disease caused by mutations of the CF transmembrane cond... more Cystic fibrosis (CF) is a common genetic disease caused by mutations of the CF transmembrane conductance regulator (CFTR) gene. Persistent lung inflammation, characterized by increasing polymorphonuclear leukocyte recruitment, is a major cause of the decline in respiratory function in CF patients, and is a leading cause of morbidity and mortality. CFTR is expressed in various cell types, including leukocytes, but its involvement in the regulation of leukocyte recruitment is unknown. Ex vivo adhesion and chemotaxis, flow cytometry, immunofluorescence, GTPases activity assays. We found that chemoattractant-induced activation of β1 and β2 integrins and of chemotaxis is defective in mononuclear cells isolated from CF patients. In contrast, polymorphonuclear leukocyte adhesion and chemotaxis were normal. The functionality of β1 and β2 integrins was restored by treatment of CF monocytes with the CFTR correcting drugs VX325 and VX809. Moreover, treatment of healthy monocytes with the CFTR inhibitor CFTR inh-172 blocked integrin activation by chemoattractants. In a murine model of lung inflammation, we found that integrin-independent migration of CF monocytes into the lung parenchyma was normal, whereas, in contrast, integrin-dependent transmigration into the alveolar space was impaired. Finally, signal transduction analysis showed that in CF monocytes chemoattractant-triggered activation of RhoA and CDC42 rho small GTPases, controlling integrin activation and chemotaxis respectively, was strongly deficient. Altogether, these data highlight the critical regulatory role of CFTR in integrin activation by chemoattractants in monocytes and identify CF as a new, cell-type selective, leukocyte adhesion deficiency disease providing new insights on CF pathogenesis.
In the present study the inhibition by nedocromil sodium of the specific receptor binding of FMLP... more In the present study the inhibition by nedocromil sodium of the specific receptor binding of FMLP was evaluated in human neutrophils (PMNs) using a FMLP-(3H) binding assay. The time course of the binding was markedly influenced by nedocromil sodium used at a concentration of 300 microM. No significant inhibition was obtained when the cells were treated with nedocromil sodium 3 microM or with sodium cromoglycate 300 microM. FMLP binding is essentially eliminated by the highest dose of nedocromil sodium. The biologic meaning of this effect in asthmatic patients should be further evaluated.
ABSTRACT In this preliminary study, the effects of nedocromil sodium (3 or 300μM) on the Superoxi... more ABSTRACT In this preliminary study, the effects of nedocromil sodium (3 or 300μM) on the Superoxide anion production and secretion of β-glucuronidase and vitamin B12-binding protein were investigated using human neutrophils stimulated with N-formyl-methionyl-leucyl-phenylalanine (FMLP; 10 or 100nM) or phorbol-myristate-acetate (PMA; 100 μg/L). O− 2 production was significantly inhibited (≈80%) in the presence of nedocromil sodium 300μM, but only when a low dose of FMLP (10nM) was used. In contrast, nedocromil was without effect on O− 2 production induced by high doses of FMLP (100μM) or by PMA (100 μg/L), and on secretion induced by either of these stimulants. Studies are in progress to ascertain whether this inhibitory effect on receptor mediated O− 2 production can be related to the therapeutic effect of nedocromil sodium.
Pseudomonas aeruginosa (Pa) is the most common virulent pathogen contributing to the pathogenesis... more Pseudomonas aeruginosa (Pa) is the most common virulent pathogen contributing to the pathogenesis of cystic fibrosis (CF). During bacterial lung colonization, the products of its metabolism are released in the extracellular space contributing to the pathogenic events associated with its presence. To gain insights on the mechanisms involved in the Pa pathogenesis we focused our attention on proteins released by Pa using a MudPIT approach combined with cell biology assays. Conditioned medium (CM) collected under aerobic and microaerobic conditions from Pa clinical strains (in early and late colonization), unlike the laboratory strain, induced expression of IL-8 mRNA in CF airway epithelial cells. We have identified proteins released by clinically relevant Pa strains, focusing on the pro-inflammatory effects as metalloproteases (MMPs). In fact, their expression pattern was associated with the highest pro-inflammatory activity measured in the early clinically isolated strain. The relation was further supported by the result of the analysis of a larger and independent set of Pa isolates derived from sporadically and chronically infected CF patients: 76% of sporadic samples expressed protease activity (n = 44), while only 27% scored positive in the chronically infected individuals (n = 38, p < 0.0001, Fisher's exact test). Finally, looking for a possible mechanism of action of bacterial MMPs, we found that CM from early clinical isolates can cleave CXCR1 on the surface of human neutrophils, suggesting a potential role for the bacterially released MMPs in the protection of the pathogen from the host's response.
The S977F mutation (c.2930C&a... more The S977F mutation (c.2930C>T) in the CFTR gene (CFTR/ABCC7) is extremely rare. We describe the case of an adult patient carrying the complex allele S977F/T5TG12 in trans with the F508del mutation. Mild respiratory manifestations arose in adulthood associated with azoospermia, acute pancreatitis, minor hemoptysis and Cl(-) levels ranging from 40 to 42 mEq/L. Diagnosis was confirmed by repeated NPD measurements, genetic DHPLC analysis and a recently described functional assay measuring cAMP-dependent cell depolarization in peripheral blood monocytes. NPD measurements, DHPLC and monocyte functional assay (CF index=-18). Results were consistent with a CF phenotype. The combined application of DHPLC and NPD analysis in the algorithm for CF diagnosis appears useful for the management of similar cases. In addition, the novel monocyte functional assay might contribute to improve our diagnostic capability, counseling and better treatment of these challenging clinical cases.
Induction of ATP Binding Cassette (ABC) proteins involved in chloride transport has been proposed... more Induction of ATP Binding Cassette (ABC) proteins involved in chloride transport has been proposed as a possible mechanism of the beneficial effects of azithromycin (AZM) in cystic fibrosis (CF) patients. This study focused on the effects of AZM on mRNA and protein expression of Multidrug Resistance-associated Protein 1 (MRP1) and Multidrug Resistance Protein 1 (MDR1) by real-time quantitative PCR, flow cytometry and gene reporter assays in two CF and two isogenic non-CF airway epithelial cell lines. We detected higher levels of MRP1 and lower levels of MDR1 mRNA in CF versus non-CF cells while both proteins were not differentially expressed. After AZM treatment we found modest differences in MRP1 and MDR1 mRNA expression while protein levels were unaffected. The ability of AZM to regulate MRP1 promoter transcriptional activity was excluded by gene reporter assays. Our data do not support the hypothesis of induction of ABC transporters by AZM.
Nasal potential difference (NPD) quantifies abnormal ion transport in cystic fibrosis. It has gai... more Nasal potential difference (NPD) quantifies abnormal ion transport in cystic fibrosis. It has gained acceptance as an outcome measure for the investigation of new therapies. To quantify the effect of solution temperature on NPD, we first examined the effect of switching from room temperature (20-25°C) to warmed (32-37°C) solutions and vice versa during each perfusion step. Secondly, standard protocols were repeated at both temperatures in the same subjects. Changing solution temperature did not alter NPD during perfusion with Ringer's solution (<1 mV) (p>0.1). During perfusion with zero chloride solution, changing from room temperature to warmed solutions tended to decrease absolute NPD (i.e. it became less negative) by 0.9 mV (p>0.1); changing from warmed to room temperature increased NPD by 2.1 mV (p<0.05). During isoprenaline perfusion, changing from room temperature to warmed solutions increased NPD by 1.5 mV (p<0.01) and from warmed to room temperature decreased NPD by 1.4 mV (p<0.05). For full protocols at room temperature or warmed in the same subjects, mean values were similar (n = 24). During warmed perfusion, group results for total chloride response had a larger standard deviation. As this increased variability will probably decrease the power of trials, this study suggests that solutions at room temperature should be recommended for the measurement of NPD.
Experimentally, lung inflammation in laboratory animals is usually detected by the presence of in... more Experimentally, lung inflammation in laboratory animals is usually detected by the presence of inflammatory markers, such as immune cells and cytokines, in the bronchoalveolar lavage fluid (BALF) of sacrificed animals. This method, although extensively used, is time, money and animal life consuming, especially when applied to genetically modified animals. Thus a new and more convenient approach, based on in vivo imaging analysis, has been set up to evaluate the inflammatory response in the lung of CFTR-deficient (CF) mice, a murine model of cystic fibrosis. Wild type (WT) and CF mice were stimulated with P. aeruginosa LPS, TNF-alpha and culture supernatant derived from P. aeruginosa (strain VR1). Lung inflammation was detected by measuring bioluminescence in vivo in mice transiently transgenized with a luciferase reporter gene under the control of a bovine IL-8 gene promoter. Differences in bioluminescence (BLI) signal were revealed by comparing the two types of mice after intratrac...
Tailored nanoparticles offer a novel approach to fight antibiotic-resistant microorganisms. We an... more Tailored nanoparticles offer a novel approach to fight antibiotic-resistant microorganisms. We analysed biogenic selenium nanoparticles (SeNPs) of bacterial origin to determine their antimicrobial activity against selected pathogens in their planktonic and biofilm states. SeNPs synthesized by Gram-negative Stenotrophomonas maltophilia [Sm-SeNPs()] and Gram-positive Bacillus mycoides [Bm-SeNPs(+)] were active at low minimum inhibitory concentrations against a number of clinical isolates of Pseudomonas aeruginosa but did not inhibit clinical isolates of the yeast species Candida albicans and C. parapsilosis. However, the SeNPs were able to inhibit biofilm formation and also to disaggregate the mature glycocalyx in both P. aeruginosa and Candida spp. The Sm-SeNPs() and Bm-SeNPs(+) both achieved much stronger antimicrobial effects than synthetic selenium nanoparticles (Ch-SeNPs). Dendritic cells and fibroblasts exposed to Sm-SeNPs(), Bm-SeNPs(+) and Ch-SeNPs did not show any loss of cell viability, any increase in the release of reactive oxygen species or any significant increase in the secretion of pro-inflammatory and immunostimulatory cytokines. Biogenic SeNPs therefore appear to be reliable candidates for safe medical applications, alone or in association with traditional antibiotics, to inhibit the growth of clinical isolates of P. aeruginosa or to facilitate the penetration of P. aeruginosa and Candida spp. biofilms by antimicrobial agents.
When cystic fibrosis (CF) is suspected Nasal Potential Difference (NPD) measurements are proposed... more When cystic fibrosis (CF) is suspected Nasal Potential Difference (NPD) measurements are proposed to support controversial diagnosis: we investigated appropriate outcomes at the CF Centre of Verona. NPD were measured in 196 subjects: 50 non-CF, 65 classical CF (the reference group) and 81 with uncertain CF (case group). Discriminating power was determined by comparison between several outcomes from the CF reference group versus non-CF: basal, amiloride, 0Cl, isoproterenol, ATP, Delta-amiloride, Delta-0Cl, Delta-isoproterenol, Delta-ATP, Delta-isoproterenol+Delta-0Cl, Wilschanski Index (WI) and Sermet score (SS). The most appropriate cut-off values for variables with the best discriminating power were then applied to the case group. Descriptive statistics, logistic regression models and ROC curve analysis were applied. WI and SS were the most powerful in discriminating CF from non-CF subjects. In the reference group sensitivity of the 0.82 WI cut-off was 98%, specificity 96%; both sensitivity and specificity of the -0.44 SS cut-off value were 100%. For the case group, WI and SS were, respectively, consistent with CF diagnosis in 94% and 92% of the cases. Formulae have the highest discriminating power and can support the diagnosis in uncertain cases; they should be utilized for standardized interpretation of NPD for diagnosis and possibly for clinical research.
Pseudomonas aeruginosa is the predominant pathogen associated with the decline of pulmonary funct... more Pseudomonas aeruginosa is the predominant pathogen associated with the decline of pulmonary function in cystic fibrosis (CF) patients. Both environment-to-host acquisition and patient-to-patient transmission have been described for P. aeruginosa infection. Epidemic clones and bacterial phenotypic adaptation to the CF lung have been recognised as independent risk factors for disease progression. So far, there is no established link between genotypic prevalence and phenotypic traits. Here, we look at the major CF patient cohort in Italy to identify shared P. aeruginosa clones and associated common phenotypic traits. A comprehensive analysis of P. aeruginosa genotypes to determine the presence of high-risk shared clones and their association to specific phenotypic traits has been performed in a major Italian CF centre. Pulsed-field gel electrophoresis (PFGE) of P. aeruginosa isolates from 338 CF subjects identified 43 profiles shared by two or more patients and 214 profiles exclusive to individual patients. There was no evidence of a P. aeruginosa outbreak, but four most prevalent pulsotypes were detected. Common phenotypic traits were recorded intra-pulsotypes, but we detected heterogeneity inter-pulsotypes. Two of the four major pulsotypes included P. aeruginosa isolates with hallmarks of adaptation to the CF airways, including loss of motility, low production of siderophore, pyocyanin and proteases, and antibiotic resistance. One of these pulsotypes grouped a high percentage of hypermutable isolates. No clear correlation between epidemiological and clinical data was found. We conclude that CF patients of this cohort shared common pulsotypes, but their phenotypic heterogeneity indicates an absence of specific traits associated to P. aeruginosa genotypic prevalence.
Deregulated immune response fails to control biofilm-forming bacteria, as Pseudomonas aeruginosa,... more Deregulated immune response fails to control biofilm-forming bacteria, as Pseudomonas aeruginosa, in the lungs of cystic fibrosis (CF) patients. HLA-G is an immune-modulatory molecule involved in respiratory diseases and infections. HLA-G mRNA and protein were analyzed in plasma and exhaled breath condensate from CF patients undergoing intravenous antibiotic treatment, CF cell line and murine model. Therapy normalizes HLA-G plasmatic in CF patients suggesting a systemic anti-inflammatory role while in CF airway system, higher expression of HLA-G is associated with P. aeruginosa infection. CF cell line and murine model expressed higher HLA-G molecules in the presence of P. aeruginosa. Plasmatic and lung HLA-G expression suggest a role in reducing systemic inflammation and supporting P. aeruginosa infection.
American Journal of Respiratory and Critical Care Medicine, 2015
Cystic fibrosis (CF) is a common genetic disease caused by mutations of the CF transmembrane cond... more Cystic fibrosis (CF) is a common genetic disease caused by mutations of the CF transmembrane conductance regulator (CFTR) gene. Persistent lung inflammation, characterized by increasing polymorphonuclear leukocyte recruitment, is a major cause of the decline in respiratory function in CF patients, and is a leading cause of morbidity and mortality. CFTR is expressed in various cell types, including leukocytes, but its involvement in the regulation of leukocyte recruitment is unknown. Ex vivo adhesion and chemotaxis, flow cytometry, immunofluorescence, GTPases activity assays. We found that chemoattractant-induced activation of β1 and β2 integrins and of chemotaxis is defective in mononuclear cells isolated from CF patients. In contrast, polymorphonuclear leukocyte adhesion and chemotaxis were normal. The functionality of β1 and β2 integrins was restored by treatment of CF monocytes with the CFTR correcting drugs VX325 and VX809. Moreover, treatment of healthy monocytes with the CFTR inhibitor CFTR inh-172 blocked integrin activation by chemoattractants. In a murine model of lung inflammation, we found that integrin-independent migration of CF monocytes into the lung parenchyma was normal, whereas, in contrast, integrin-dependent transmigration into the alveolar space was impaired. Finally, signal transduction analysis showed that in CF monocytes chemoattractant-triggered activation of RhoA and CDC42 rho small GTPases, controlling integrin activation and chemotaxis respectively, was strongly deficient. Altogether, these data highlight the critical regulatory role of CFTR in integrin activation by chemoattractants in monocytes and identify CF as a new, cell-type selective, leukocyte adhesion deficiency disease providing new insights on CF pathogenesis.
In the present study the inhibition by nedocromil sodium of the specific receptor binding of FMLP... more In the present study the inhibition by nedocromil sodium of the specific receptor binding of FMLP was evaluated in human neutrophils (PMNs) using a FMLP-(3H) binding assay. The time course of the binding was markedly influenced by nedocromil sodium used at a concentration of 300 microM. No significant inhibition was obtained when the cells were treated with nedocromil sodium 3 microM or with sodium cromoglycate 300 microM. FMLP binding is essentially eliminated by the highest dose of nedocromil sodium. The biologic meaning of this effect in asthmatic patients should be further evaluated.
ABSTRACT In this preliminary study, the effects of nedocromil sodium (3 or 300μM) on the Superoxi... more ABSTRACT In this preliminary study, the effects of nedocromil sodium (3 or 300μM) on the Superoxide anion production and secretion of β-glucuronidase and vitamin B12-binding protein were investigated using human neutrophils stimulated with N-formyl-methionyl-leucyl-phenylalanine (FMLP; 10 or 100nM) or phorbol-myristate-acetate (PMA; 100 μg/L). O− 2 production was significantly inhibited (≈80%) in the presence of nedocromil sodium 300μM, but only when a low dose of FMLP (10nM) was used. In contrast, nedocromil was without effect on O− 2 production induced by high doses of FMLP (100μM) or by PMA (100 μg/L), and on secretion induced by either of these stimulants. Studies are in progress to ascertain whether this inhibitory effect on receptor mediated O− 2 production can be related to the therapeutic effect of nedocromil sodium.
Pseudomonas aeruginosa (Pa) is the most common virulent pathogen contributing to the pathogenesis... more Pseudomonas aeruginosa (Pa) is the most common virulent pathogen contributing to the pathogenesis of cystic fibrosis (CF). During bacterial lung colonization, the products of its metabolism are released in the extracellular space contributing to the pathogenic events associated with its presence. To gain insights on the mechanisms involved in the Pa pathogenesis we focused our attention on proteins released by Pa using a MudPIT approach combined with cell biology assays. Conditioned medium (CM) collected under aerobic and microaerobic conditions from Pa clinical strains (in early and late colonization), unlike the laboratory strain, induced expression of IL-8 mRNA in CF airway epithelial cells. We have identified proteins released by clinically relevant Pa strains, focusing on the pro-inflammatory effects as metalloproteases (MMPs). In fact, their expression pattern was associated with the highest pro-inflammatory activity measured in the early clinically isolated strain. The relation was further supported by the result of the analysis of a larger and independent set of Pa isolates derived from sporadically and chronically infected CF patients: 76% of sporadic samples expressed protease activity (n = 44), while only 27% scored positive in the chronically infected individuals (n = 38, p < 0.0001, Fisher's exact test). Finally, looking for a possible mechanism of action of bacterial MMPs, we found that CM from early clinical isolates can cleave CXCR1 on the surface of human neutrophils, suggesting a potential role for the bacterially released MMPs in the protection of the pathogen from the host's response.
The S977F mutation (c.2930C&a... more The S977F mutation (c.2930C>T) in the CFTR gene (CFTR/ABCC7) is extremely rare. We describe the case of an adult patient carrying the complex allele S977F/T5TG12 in trans with the F508del mutation. Mild respiratory manifestations arose in adulthood associated with azoospermia, acute pancreatitis, minor hemoptysis and Cl(-) levels ranging from 40 to 42 mEq/L. Diagnosis was confirmed by repeated NPD measurements, genetic DHPLC analysis and a recently described functional assay measuring cAMP-dependent cell depolarization in peripheral blood monocytes. NPD measurements, DHPLC and monocyte functional assay (CF index=-18). Results were consistent with a CF phenotype. The combined application of DHPLC and NPD analysis in the algorithm for CF diagnosis appears useful for the management of similar cases. In addition, the novel monocyte functional assay might contribute to improve our diagnostic capability, counseling and better treatment of these challenging clinical cases.
Induction of ATP Binding Cassette (ABC) proteins involved in chloride transport has been proposed... more Induction of ATP Binding Cassette (ABC) proteins involved in chloride transport has been proposed as a possible mechanism of the beneficial effects of azithromycin (AZM) in cystic fibrosis (CF) patients. This study focused on the effects of AZM on mRNA and protein expression of Multidrug Resistance-associated Protein 1 (MRP1) and Multidrug Resistance Protein 1 (MDR1) by real-time quantitative PCR, flow cytometry and gene reporter assays in two CF and two isogenic non-CF airway epithelial cell lines. We detected higher levels of MRP1 and lower levels of MDR1 mRNA in CF versus non-CF cells while both proteins were not differentially expressed. After AZM treatment we found modest differences in MRP1 and MDR1 mRNA expression while protein levels were unaffected. The ability of AZM to regulate MRP1 promoter transcriptional activity was excluded by gene reporter assays. Our data do not support the hypothesis of induction of ABC transporters by AZM.
Nasal potential difference (NPD) quantifies abnormal ion transport in cystic fibrosis. It has gai... more Nasal potential difference (NPD) quantifies abnormal ion transport in cystic fibrosis. It has gained acceptance as an outcome measure for the investigation of new therapies. To quantify the effect of solution temperature on NPD, we first examined the effect of switching from room temperature (20-25°C) to warmed (32-37°C) solutions and vice versa during each perfusion step. Secondly, standard protocols were repeated at both temperatures in the same subjects. Changing solution temperature did not alter NPD during perfusion with Ringer's solution (<1 mV) (p>0.1). During perfusion with zero chloride solution, changing from room temperature to warmed solutions tended to decrease absolute NPD (i.e. it became less negative) by 0.9 mV (p>0.1); changing from warmed to room temperature increased NPD by 2.1 mV (p<0.05). During isoprenaline perfusion, changing from room temperature to warmed solutions increased NPD by 1.5 mV (p<0.01) and from warmed to room temperature decreased NPD by 1.4 mV (p<0.05). For full protocols at room temperature or warmed in the same subjects, mean values were similar (n = 24). During warmed perfusion, group results for total chloride response had a larger standard deviation. As this increased variability will probably decrease the power of trials, this study suggests that solutions at room temperature should be recommended for the measurement of NPD.
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synthetic selenium nanoparticles (Ch-SeNPs). Dendritic cells and fibroblasts exposed to Sm-SeNPs(), Bm-SeNPs(+) and Ch-SeNPs did not show any loss of cell viability, any increase in the release of reactive
oxygen species or any significant increase in the secretion of pro-inflammatory and immunostimulatory cytokines. Biogenic SeNPs therefore appear to be reliable candidates for safe medical applications,
alone or in association with traditional antibiotics, to inhibit the growth of clinical isolates of P. aeruginosa or to facilitate the penetration of P. aeruginosa and Candida spp. biofilms by antimicrobial agents.
synthetic selenium nanoparticles (Ch-SeNPs). Dendritic cells and fibroblasts exposed to Sm-SeNPs(), Bm-SeNPs(+) and Ch-SeNPs did not show any loss of cell viability, any increase in the release of reactive
oxygen species or any significant increase in the secretion of pro-inflammatory and immunostimulatory cytokines. Biogenic SeNPs therefore appear to be reliable candidates for safe medical applications,
alone or in association with traditional antibiotics, to inhibit the growth of clinical isolates of P. aeruginosa or to facilitate the penetration of P. aeruginosa and Candida spp. biofilms by antimicrobial agents.