Adenosine A2(A) receptor gene polymorphism (1976C>T) affects coronary flow reserve response during vasodilator stress testing in patients with non ischemic-dilated cardiomyopathy.

OBJECTIVES: Patients with non ischemic-dilated cardiomyopathy (DCM) are characterized by an activation of the adenosinergic system and reduced coronary flow reserve (CFR) evaluated by transthoracic Doppler echocardiography during vasodilator adenosinergic stress (dipyridamole administration). The aim of this study was to assess whether genetic polymorphisms (263C>T and 1976C>T) of the A2(A) receptor gene affect CFR response in patients with DCM. METHODS: We enrolled a group of 80 patients with DCM (55 male; age, 62±10.3 years) and 162 healthy volunteers (55 male; age, 45.1±9.5 years). Doppler-derived CFR (high-dose dipyridamole coronary diastolic peak flow velocity to resting coronary peak flow velocity ratio) of distal left anterior descending artery was determined in DCM. A2(A) receptor genotyping was determined in all patients by polymerase chain reaction-restriction fragment length polymorphism analysis. The expression of A2(A) protein and mRNA was also assessed in healthy controls. RESULTS: The genotype distribution of the 263C>T (P=0.5) and 1976C>T (P=0.8) polymorphisms was not significantly different between patients and controls. Patients with 1976TT genotype had significantly lower CFR value than 1976CC patients (2.3±0.7, 2.0±0.5 and 1.9±0.4, P<0.05 for CC, CT and TT genotypes, respectively). Controls who were heterozygous (P=0.02) or homozygous (P=0.001) for the T1976 allele showed a significant increase in A2(A) receptor protein. CONCLUSION: These data demonstrate that A2(A) 1976C>T polymorphism is associated with a blunted coronary vasodilatory response in patients with DCM, and support a direct consequences of this single nucleotide polymorphism for protein expression. Additional studies are needed to better define the functional role of this genetic variant as well as to clarify the potential clinical impact of genetics during pharmacological stress cardiac imaging.

Pro/Anti-inflammatory cytokine imbalance in postischemic left ventricular remodeling.

OBJECTIVES: Cytokines play an important role in left ventricular remodeling consequent to myocardial ischemia. The aim of this study was to correlate cytokine production and lymphocyte apoptosis to post-ischemic left ventricular remodeling in patients affected by acute myocardial infarction (AMI) undergoing primary cutaneous angioplasty (PCI). METHODS: In 40 patients, affected by AMI and undergoing PCI, we evaluated peripheral blood mononuclear cells (PBMCs), tumor necrosis factor-alpha (TNF-alpha) and interleukin 10 (IL10) production and apoptosis on day 1, day 3, day 7, 1 month and 6 months after PCI. Patients were divided into two subgroups of remodeling or not remodeling by echocardiographic criteria. RESULTS: In the subgroup of remodeling patients, at each timepoint TNF-alpha production was increased significantly in comparison with the subgroup of not remodeling patients. IL10 production was statistically lower in remodeling subjects than in not remodeling ones 1 and 6 months after reperfusion. There were no differences between the two groups as regards lymphomonocyte apoptosis. CONCLUSIONS: We found an increased production of pro-inflammatory cytokine TNF-alpha and a corresponding decrease of anti-inflammatory/regulatory cytokine IL10 in remodeling patients and we concluded that this cytokine imbalance resulted in pro-inflammatory effects which might contribute to the progression of left ventricular remodeling.

Human rheumatoid synoviocytes express functional P2X7 receptors.

Human type B synoviocytes are involved in joint injury during rheumatic diseases by producing inflammatory mediators such as interleukin-6 (IL-6). The increased level of purine and pirimidine nucleotides in the synovial fluid of rheumatoid arthritis (RA) patients could activate the large family of P2 receptors. Thus, we investigated the presence of P2 receptors in human type B synoviocytes from rheumatoid joints, also evaluating whether the P2X7 receptor is involved in IL-6 release. Reverse transcriptase polymerase chain reaction analysis revealed messenger ribonucleic acid (mRNA) expression for the P2X1, P2X2, P2X4, P2X5, P2X6, P2X7, P2Y1, P2Y4, P2Y11, P2Y12, P2Y13, and P2Y14 but not the P2X3, P2Y2, and P2Y6 receptors. The expression of the P2X7 receptor was confirmed by Western blot analysis. Adenosine triphosphate (ATP) and the P2X7 receptor agonist 2'-3'-O-(4-benzoylbenzoyl)ATP (BzATP) triggered an increase in intracellular calcium, thereby suggesting the expression of functional P2 receptors, including the P2X7 receptor. Moreover, BzATP treatment upregulated both IL-6 mRNA and protein expression. Synoviocytes spontaneously released low quantities of IL-6; the incubation with BzATP induced the release of larger amounts of the cytokine, and such a release was blunted by the P2X7 antagonist oxidized ATP. The selective P2X1 and P2X3 receptor agonist alpha,beta-methylene ATP did not affect IL-6 release. Finally, BzATP failed to induce a significant uptake of the large-molecule YO-PRO, thus suggesting the lack of pore formation after P2X7 receptor stimulation. In conclusion, among the different P2 receptors expressed on human RA type B synoviocytes, the P2X7 receptor may modulate IL-6 release but not inducing changes in cell membrane permeability.

Using peripheral blood mononuclear cells to determine proteome profiles in human cardiac failure.

BACKGROUND: In chronic heart failure (CHF), peripheral blood mononuclear cells (PBMC) might undergo structural and/or functional alterations as a consequence of the development and progression of the disease. AIMS: This study was aimed at: (1) assessing the proteome profile of PBMC from Controls and CHF subjects, (2) identifying differentially-expressed proteins in healthy subjects and patients, and (3) analysing the expression of these proteins in patients after heart transplantation. METHODS AND RESULTS: Proteome changes were assessed in PBMC from 8 healthy and 11 end-stage CHF (6 Ischaemic Heart Failure [IHF], 5 Dilated CardioMyopathy [DCM]) subjects by gel electrophoresis, PD-Quest analysis and mass spectrometry. Eighteen proteins were differentially expressed in Controls and CHF patients. However, among CHF patients, these proteins were equally expressed in IHF and DCM subjects. Eleven proteins were found to belong to 4 functional classes (3 cytoskeletal, 4 cell-cycle progression, 2 stress response and DNA repair, 2 energetic metabolism proteins). Changes in three of the differentially-expressed proteins were also confirmed by Western blot and were reversed after heart transplantation. CONCLUSION: Results demonstrate an altered protein expression profile in PBMC of CHF patients compared to Controls, thus providing a basis for further diagnostic and prognostic tests for CHF.

Other uses of homologous skin grafts and skin bank bioproducts.

The main use of homologous skin grafts or grafts of related bioproducts is in the treatment of severe burns. However, various new clinical and experimental sectors, in which this type of skin substitute can be useful, have recently emerged. The main new clinical indications for skin allografts include: skin loss, surgical wounds and bullous diseases. In these fields donor skin can be used for different purposes: as a physiological biological dressing to control pain and protect deep structures such as tendons, bones, cartilage and nerves, and to promote reepithelization with a significant reduction in healing time, and as skin substitute with dermal tissue to guide repair and make it as physiological as possible. In particular, skin bank bioproducts are currently used in the treatment of several conditions such venous and arterial leg ulcers, pressure ulcers, diabetic foot ulcers, pyoderma gangrenosum, post traumatic lesions, Mohs surgery, reconstructive surgery, wound cover in critical areas, aesthetic surgery, congenital epidermolysis bullosa and Lyell's syndrome. Skin bank bioproducts have also been used for experimental indications, to study in vitro toxicology and in vitro skin biology. Recently the demonstration that de-epidermized dermis (DED) has all the characteristics of an excellent dermal substitute into which various types of cells can be introduced and made to develop, opens exciting new possibilities of research in the field of wound healing and tissue engineering. Our preliminary observations seems to indicate that CD 34+ stem cells from umbilical cord blood can survive in DED and in a few weeks populate collagen bundles. The observation of tubular structures without lumina close to collagen bundles as well as clusters of epithelioid or fibroblast-shaped cells may represent aspects of differentiation of CD 34+ stem cells. More detailed and sophisticated studies are clearly needed to answer all the questions that these initial observations pose. Anyway the 3-dimensional model proposed seems to be suitable for the study of the behaviour of peripheral CD 34+ and perhaps also other types of stem cells in 3-dimensional dermal matrix.

Psychosine-induced apoptosis and cytokine activation in immune peripheral cells of Krabbe patients.

Globoid cell leukodystrophy or Krabbe disease (KD), is a hereditary disorder caused by galactosylceramidase deficiency. Progressive accumulation of psychosine is considered to be the critical pathogenetic mechanism of cell death in the Krabbe brain. Psychosine mechanism of action has not been fully elucidated. It seems to induce apoptosis in oligodendrocytes through a mitochondrial pathway and to up-regulate inflammatory cytokines production resulting in oligodendrocyte loss. Our aim was to evaluate the role of psychosine in apoptotic cell death and inflammatory response in a group of patients affected by KD using peripheral blood lymphocytes (PBLs) and peripheral blood mononuclear cells (PBMCs) as a cellular model. PBLs from KP and healthy controls were exposed to 20 microM psychosine and analysed by flow cytometry, agarose gel electrophoresis and fluorescence microscopy. Our results showed that psychosine induces apoptosis in PBLs through a mitochondrial pathway, but the apoptotic response was quite low especially KP. The role of psychosine in the up-regulation of cytokines (TNFalpha, IL8 and MCP1) has been evaluated by ELISA in PBMCs from KP and controls after stimulation with LPS and phytohemagglutinin. Both in basal condition and after LPS stimulation, cells from KP showed a significant increase in TNF-alpha production, reduced MCP1 levels and no modification in IL8. These results indicate that lymphomonocytes from KP had a basal proinflammatory pattern that was amplified by psychosine. In conclusion, the reduced apoptotic response and the atypical cytokine production observed in our experiments, suggest an involvement of inflammatory pattern in immune peripheral cells of KP.

Upregulation of A2A adenosine receptor expression by TNF-alpha in PBMC of patients with CHF: a regulatory mechanism of inflammation.

BACKGROUND: Tumor necrosis factor (TNF)-alpha plays a role in congestive heart failure (CHF). A2A adenosine receptor (A(2A)R) activation on immune cells putatively reduces the release of cytokines contributing to CHF progression. The study is aimed at determining the role of the A(2A)R in the modulation of TNF-alpha production, and the ex vivo effect of TNF-alpha on A(2A)R in peripheral blood mononuclear cells (PBMC) from CHF patients. METHODS AND RESULTS: Plasma levels of TNF-alpha and TNF-alpha production from lipopolysaccharide (LPS)-stimulated PBMC were evaluated in 26 CHF patients in comparison to controls. The effects of the A(2A)R agonist CGS-21680 and antagonist ZM-241385 on TNF-alpha production from PBMC were also evaluated. Finally, reverse transcriptase-polymerase chain reaction and Western blot analyses of A(2A)R in PBMC were performed in TNF-alpha-treated and untreated cells. TNF-alpha production from LPS-stimulated PBMC was enhanced in CHF patients with respect to controls. CGS-21680 blunted TNF-alpha production in both groups; ZM-241385 reverted this effect. A(2A)R expression in PBMC was higher in CHF patients than in controls. TNF-alpha addition produced an increase in A(2A)R in PBMC from controls but not in PBMC from CHF patients. CONCLUSIONS: PBMC from CHF patients show an upregulation of A(2A)R-mediated inhibition of TNF-alpha, which may represents a mechanism of protection against inappropriate cytokine production.