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Biomedical subjects

Michele Zorzetto

Publications and source records attributed to Michele Zorzetto.

11 recordsLinked to original sources

Expression of receptor for advanced glycation end products in sarcoid granulomas.

RATIONALE: The receptor for advanced glycation end products (RAGE) engages a number of ligands implicated in inflammatory processes. The RAGE coding gene maps to the 6p21.32 region, close to the genes DRB1 and BTNL2, which are associated with sarcoidosis. OBJECTIVES: We investigated a possible implication of RAGE in sarcoid granulomas. METHODS: RAGE and major ligands (N-epsilon-carboxy-methyl-lysine [CML], S100A12, and S100B) expression was investigated by immunostaining of 99 paraffin-embedded biopsies of sarcoid tissues, and expression patterns were determined. Among the three RAGE gene single-nucleotide polymorphisms investigated, -374 T/A was selected, characterized in terms of transcriptional effect (immunocytochemistry and real-time polymerase chain reaction), and its frequency was determined in DNA extracted from biopsies. MEASUREMENTS AND RESULTS: RAGE, CML, S100A12, and S100B immunoreactivity was observed in all sarcoid granulomas, although at different intensities. The degree of RAGE expression significantly correlated with the degree of S100A12 expression. The -374 TT/AT genotypes, associated with higher RAGE transcriptional activity, were more frequent in the sarcoidosis biopsy group than in control subjects, and the association was confirmed in a second, independent series of 101 patients with sarcoidosis. CONCLUSIONS: We showed the association of RAGE and its ligands with sarcoidosis and suggest that an intrinsic genetic factor could be in part involved in its expression. In Italian patients, the -374 T/A polymorphism seems to be significantly associated with this disease.

Adolescent↗

The receptor for advanced glycation end products and its ligands: a new inflammatory pathway in lung disease?

The binding of the receptor for advanced glycation end products (RAGE) with its ligands begins a sustained period of cellular activation and inflammatory signal amplification in different tissues and diseases. This binding could represent an as yet uninvestigated pathway of inflammatory reaction in the lung, where the presence of the receptor has been largely documented and advanced glycation end products (AGEs) are produced by nonenzymatic glycation and oxidation of proteins and lipids, driven by smoke and pollutants exposure or inflammatory stress. We immunohistochemically assessed the expression of RAGE and of its major proinflammatory ligands, N-epsilon-carboxy-methyl-lysine, S100B and S-100A12 in normal lung and in non-neoplastic lung disorders including smoke-related airway disease, granulomatous inflammation, postobstructive damage and usual interstitial pneumonia. In normal lung low expression of the receptor was observed in bronchiolar epithelia, type II pneumocytes, macrophages and some endothelia. S100A12 and S100B were expressed, respectively, in granulocytes and in dendritic cells. Carboxy-methyl-lysine was present in bronchiolar epithelia and macrophages. In all pathological conditions associated with inflammation and lung damage overexpression of both the receptor and of AGEs was observed in bronchiolar epithelia, type II alveolar pneumocytes, alveolar macrophages and endothelia. RAGE overexpression was more evident in epithelia associated with inflammatory cell aggregates. Fibroblasts in usual interstitial pneumonia expressed both the receptor and AGEs. The number of S100A12 and S100B immunoreactive inflammatory cells was variable. S100A12 was also expressed in mononuclear inflammatory cells and in activated epithelia. The activation of the inflammatory pathway controlled by the RAGE is not specific of a single lung disease, however, it may be relevant as a nonspecific pathway of sustained inflammation in lung tissue, and on this basis therapeutic approaches based on receptor blockage can be envisaged.

Airway Obstruction↗

-374T/A polymorphism of the RAGE gene promoter in relation to severity of coronary atherosclerosis.

BACKGROUND: We have recently reported that homozygosity for the minor A-allele of RAGE (receptor for advanced glycation end products) -374T/A polymorphism may exert a protective effect toward the development of angiographic coronary artery disease (CAD). Here we focused on the putative involvement of this functional RAGE polymorphism on the severity of coronary atherosclerosis as assessed by angiography. METHODS: In a total of 234 consecutive Caucasian patients with angiographically proven CAD, the severity of coronary atherosclerosis was assessed by the number of diseased vessels (greater than 50% stenosis). Genotyping for the -374T/A variant was performed by means of PCR-RFLPs. RESULTS: The mean number of diseased vessels was significantly lower in patients with the AA genotype (1.47+/-0.68) than in those with the AT or TT genotype (1.88+/-0.82, p=0.029). After confounding variables were controlled for, the number of diseased vessels remained significantly different in the AA genotype carriers from that in the AT or TT carriers (p=0.041, ANCOVA). CONCLUSIONS: Our data suggest that the RAGE -374T/A polymorphism is one of the likely candidate determinants for the genetic variance of disease phenotype in coronary atherosclerosis.

Adenosine↗

Identification of a novel alpha1-antitrypsin null variant (Q0Cairo).

Alpha1-antitrypsin deficiency (AATD) is a common hereditary disorder associated with high risk of developing pulmonary emphysema early in life and, to a lesser extent, chronic liver disease and cirrhosis. Among Northern Europeans and Northern Americans, more than 95% of individuals with emphysema associated with AATD carry the most frequent AAT deficient gene variants, PI*Z and PI*S. Rare AAT deficient variants account for 2-4% of AATD individuals. We extend the sequence data on AAT by characterizing a novel Null allele detected in 3 subjects: a carrier belonging to an Italian/Egyptian family and 2 members of a family originating from Southern Italy. The mutation raised on a M1 (Ala213) base allele and it is characterized by an A-->T transversion at exon III, nt 218, codon 259 (AAA-->TAA) (GeneBank accession number AY 256958). The transversion results in a premature stop codon (Lys259AAA-->Stop259TAA). The proposed nomenclature of Q0cairo is from the birthplace of the father of first recognized subject. Serum levels and isoelectric focusing of AAT were consistent with the presence of the Null variant.

Adolescent↗

NOD2/CARD15 gene polymorphisms in idiopathic pulmonary fibrosis.

BACKGROUND: Micro-organisms, behaving in a non-infectious fashion, may be among the exogenous factor(s) believed to trigger idiopathic pulmonary fibrosis (IPF). One possible strategy to identify an individual's susceptibility to such microbial triggers, which are likely to be ubiquitous, is to investigate the molecular processes involved in their recognition. NOD2/CARD15 is a specific pattern recognition receptor protein, whose genetic variants have been previously associated with susceptibility to Crohn's disease. AIM: The aim of this work was to determine the frequencies of the three major NOD2/CARD 15 gene mutations (R702W, G908R and 1007fsinC) in a series of 76 subjects affected by IPF, and to compare them with those found in three groups of controls: a group with sarcoidosis (a disorder in which an involvement of the NOD2/CARD15 gene has already been investigated and rejected in different ethnic groups; 67 subjects) and two groups of healthy subjects (218 and 208 subjects, respectively), matched for gender, age, and ethnicity. RESULTS: We found no differences in frequencies of NOD2/CARD15 gene polymorphisms among the four groups investigated. CONCLUSION: We conclude that the NOD2/CARD15 gene is not likely to be involved in susceptibility to IPF in Italians.

Aged↗

A novel method for rapid genotypic identification of alpha 1-antitrypsin variants.

There is worldwide growing awareness of alpha 1-antitrypsin deficiency (AATD), a major hereditary disorder in Caucasians. The gold standard for laboratory diagnosis of AATD is thin-layer isoelectrofocusing (IEF), which is labor intensive and should be performed in reference laboratories. The aim of this study was to find an easy, fast, and cheap method for detecting alpha1-antitrypsin S and Z variants, the most frequent variants associated with AATD. The novel method herein described is based on SexAI/Hpy99I RFLP. We studied samples from 90 subjects enrolled in the Italian National Registry for AATD, previously typed by isoelectrofocusing. We found a complete agreement among our results, IEF, and genotypes obtained by standard methods. We concluded that this novel method combines efficiency, ease, swiftness, and low cost.

DNA Primers↗

Relationship between the -374T/A RAGE gene polymorphism and angiographic coronary artery disease.

The receptor for advanced glycation end products (RAGE) is thought to play a critical role in diabetic atherosclerosis. Accordingly, a functional -374T/A polymorphism in RAGE gene promoter has been associated with macrovascular complications in type 1 diabetic patients. However, the extent to which this common variant influences the risk of coronary artery disease (CAD) in the general population remains to be determined. We genotyped the -374T/A RAGE polymorphism in 259 non-diabetic individuals, of whom 175 had angiographically documented coronary artery disease (CAD patients) and 84 had normal coronary angiography (CAD-free control subjects). Homozygosity for the -374A allele was found in 9.7% of the CAD patients versus 22.6% of the CAD-free subjects (p=0.005). By means of a multiple logistic regression analysis, the AA genotype of the -374T/A polymorphism was shown to be independently associated with a reduced risk of CAD (adjusted odds ratio 0.33, 95% CI 0.15 to 0.73; p=0.006). Our observations suggest that the -374T/A polymorphism of the RAGE gene may reduce susceptibility to CAD, thus exerting a protective effect on coronary risk. Future pathophysiological studies may be worthwhile to clarify the mechanisms behind this association.

Adenosine↗

Complement receptor 1 gene polymorphisms are associated with idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic, fibrotic disorder underlain by aberrant wound healing of repeated lung injury. Environmental triggers and genetic background are likely to act as modifiers of the fibrotic response. Erythrocyte complement receptor 1 is a membrane protein mediating the transport of immune complexes to phagocytes. Three gene polymorphisms are related to the erythrocyte surface density of complement receptor 1 molecules, which in turn are related to the rate of immune complexes' clearance. There is evidence of association between sarcoidosis and the complement receptor 1 gene. We wondered whether IPF is associated with the complement receptor 1 gene alleles coding for a reduced molecule/erythrocyte ratio. We studied 74 patients and 166 control subjects. Three polymorphic sites of the gene, A3650G exon 22, HindIII RFLP intron 27, and C5507G exon 33, were analyzed and found to be in linkage disequilibrium. The GG genotype for the C5507G exon 33 polymorphism was significantly more common in patients with IPF than in control subjects (odds ratio = 6.232, 95% confidence interval = 2.198-18.419, p = 0.00023). The significant difference was found in both sexes. These findings agree with speculations on the role of the complement receptor 1 gene in idiopathic pulmonary fibrosis.

Aged↗

Complement receptor 1 gene polymorphisms in sarcoidosis.

Sarcoidosis is likely to result from exposure of genetically susceptible hosts to environmental agents. Erythrocyte (E) complement receptor 1 (CR1) is a membrane protein mediating the transport of immune complexes (ICs) to phagocytes, and at least three polymorphisms on the CR1 gene are related to erythrocyte surface density of CR1 molecules, in turn related to the rate of IC clearance from circulation. We hypothesized that sarcoidosis could be associated with increased frequency of the CR1 gene alleles coding for reduced CR1/E ratio. We studied 91 sarcoid patients and two control groups: 94 healthy volunteers and 71 patients with chronic obstructive pulmonary disease (COPD). Three polymorphic sites of CR1 gene, His1208Arg, intron 27 HindIII/RFLP, and Pro1827Arg, were analyzed. The three polymorphisms were in linkage disequilibrium. The GG genotype for the Pro1827Arg (C(5507)G) polymorphism was significantly associated with sarcoidosis in comparison to both control groups (odds ratio [OR] = 3.13; 95% confidence interval [CI] 1.49-6.69 versus healthy control subjects, and OR= 2.82, 95% CI 1.27-6.39 versus COPD control subjects). The same genotype was particularly associated to disease in females (OR = 7.05; 95% CI 3.10-16.61 versus healthy control subjects). These findings agree with speculations on the role of CR1 gene as a possible susceptibility factor.

Adult↗