Alessandra Tritarelli

Intracoronary microparticles and microvascular obstruction in patients with ST elevation myocardial infarction undergoing primary percutaneous intervention

AIMS Microparticles (MP) are cell-derived fragments known to be increased in the blood of patients with acute coronary syndromes. We aimed to assess, in ST elevation myocardial infarction (STEMI), the systemic and local (in the culprit coronary artery) levels of platelet-derived MP (PMP, CD42+CD31+) and endothelial-derived MP (EMP, CD42-CD31+) and their relation to indexes of microvascular obstruction (MVO). METHODS AND RESULTS In 78 STEMI patients undergoing successful primary percutaneous coronary intervention, blood samples were sequentially drawn from the aorta and the culprit coronary artery for cytofluorimetric MP detection. Thrombolysis in myocardial infarction (TIMI) flow, thrombus score (TS), corrected TIMI frame count (cTFC), myocardial blush grade (MBG), quantitative blush evaluator (QuBE) score, and 90 min ST resolution (ΣSTR) were calculated. Both PMP and EMP levels were significantly higher in the intracoronary than in the aortic blood samples. Intracoronary PMP and EMP levels were positively related to TS and cTFC and inversely related to MBG and QuBE. Aortic PMP (but not EMP) levels were related to TS and cTFC and, inversely, to QuBE. Intracoronary PMP were independently related to angiographic and electrocardiographic MVO in a multivariate model. CONCLUSION The correlations of intracoronary EMP and of both systemic and intracoronary PMP levels with TS support the role of MP as markers of ongoing thrombosis. Moreover, the correlation of intracoronary MP with indexes of microvascular dysfunction suggests, for the first time, a possible direct role of MP in the pathogenesis of MVO.

Anti-tissue transglutaminase antibodies from celiac patients are responsible for trophoblast damage via apoptosis in vitro

OBJECTIVES:The association between maternal celiac disease (CD) and both reduced fertility and increased risk of adverse pregnancy-related events has been long documented. However, no evidences are available regarding the pathogenic mechanisms of this link. The aim of this study was to determine whether anti-tissue transglutaminase (anti-tTG) antibodies are involved in the damage of trophoblastic cells in vitro.METHODS:Human primary trophoblastic cells, isolated from term placenta, were exposed to anti-tTG immunoglobulin G (IgG) antibodies, both commercially available and separated from sera of three untreated celiac women. The ability of anti-tTG antibodies to bind to trophoblastic cells, invasiveness of placental cells through a layer of extracellular matrix, and the activity of cellular matrix metalloprotease (MMP) and cellular apoptosis were evaluated, as indicators of trophoblast damage, by TdT-mediated dUTP digoxigenin nick end labeling (TUNEL) and annexin V expression.RESULTS:Anti-tTG IgG showed a specific dose- and time-dependent binding to human trophoblast. In addition, trophoblastic cells, after being exposed to anti-tTG IgG antibodies, both commercially available and separated from sera of celiac women, showed an impaired invasiveness, a decreased activity of cellular MMP, and a greater percentage of TUNEL positivity and annexin V positivity.CONCLUSIONS:We showed that the binding of anti-tTG antibodies to trophoblast might represent a key mechanism by which the embryo implantation and pregnancy outcome are impaired in untreated celiac pregnant women. Because healthy trophoblast development is essential for placental and fetal development, these data provide a novel mechanism for CD-induced infertility, early pregnancy loss, and intrauterine growth retardation.

Pleiotropic Beneficial Effects of Sonic Hedgehog Gene Therapy in an Experimental Model of Peripheral Limb Ischemia

We have previously shown that the signaling pathway of the embryonic morphogen Sonic hedgehog (Shh) is recapitulated in the postnatal skeletal muscle in response to ischemia. We have also demonstrated that Shh is an indirect angiogenic agent upregulating various families of angiogenic growth factors and that Shh gene therapy improves angiogenesis and heart function in experimental models of myocardial ischemia. Based on these findings, we hypothesized that Shh gene therapy is beneficial in an experimental model of peripheral ischemia. We found that intramuscular (i.m.) treatment with a plasmid encoding the Shh human gene (phShh) increased blood flow, capillary density, and arteriole density in mice in which peripheral circulation of the hindlimb was disrupted by removal of the common femoral artery. Shh gene therapy also enhanced vasculogenesis, by increasing the number of circulating bone marrow (BM)-derived endothelial precursors and improving the contribution of these cells to the process of neovascularization. Finally, phShh treatment induced upregulation of prototypical angiogenic, arteriogenic, and vasculogenic factors, such as vascular endothelial growth factor (VEGF), angiopoietin 1 (Ang-1), and stromal cell-derived factor-1 (SDF-1α). These data suggest that Shh gene therapy merits further investigation for its ability to trigger the expression of potent trophic factors and stimulate pleiotropic aspects of neovascularization in the setting of ischemia.

Are endothelial progenitor cells mobilized by myocardial ischemia or myocardial necrosis? A cardiac magnetic resonance study

BACKGROUND In ST-elevation myocardial infarction (STEMI) patients, the main stimuli involved in endothelial progenitor cells (EPCs) mobilization are not fully understood. We aimed to assess by cardiac magnetic resonance (CMR) whether the extent of ischemic myocardium (area at risk (AAR)) or of necrotic myocardium (infarct size (IS)) can be correlated to levels of circulating EPCs. METHODS Peripheral EPCs were measured in fifteen STEMI patients at 24h after successful primary percutaneous coronary intervention (pPCI). Between two and four days after pPCI all patients underwent CMR assessment of myocardial AAR, IS, myocardial salvage (MS) and microvascular obstruction at late gadolinium enhancement CMR (LG-MVO). RESULTS CD34+/KDR+, CD34+/KDR+/CD45dim, CD34+/KDR+/CD45-, EPCs were related to extent of AAR (rho=0.51, p=0.05; rho=0.55, p=0.03; rho=0.72, p=0.002, respectively), while no relationships were detected with IS, MS or LG-MVO. CONCLUSIONS Our data show that EPCs were strongly correlated to extent of myocardial AAR, thus suggesting that progenitor cells mobilization in STEMI develops in response to myocardial ischemia and not to myocardial necrosis.

Comparison of the effects of ramipril versus telmisartan on high-sensitivity C-reactive protein and endothelial progenitor cells after acute coronary syndrome.

To compare the anti-inflammatory and endothelial progenitor cell mobilizing effects of ramipril and telmisartan in patients presenting with acute coronary syndrome (ACS), 42 patients with ACS were randomized after successful percutaneous coronary intervention to ramipril 5 mg/day (22 patients) or telmisartan 80 mg/day (20 patients). Peripheral blood samples were drawn at baseline and at 20 days to measure high-sensitivity C-reactive protein and to assess 4 populations of progenitor cells by flow cytometry, namely CD34+/KDR+, CD34+/CD133+, CD34+/CD133+/CD45-, and CD34+/KDR+/CD45- cells. High-sensitivity C-reactive protein levels, similar in the 2 groups at baseline, were significantly more decreased by telmisartan than by ramipril at follow up (p = 0.013 for time-by-drug interaction). The main effect for time was also significant (p <0.001). CD34+/KDR+ and CD34+/CD133+ cells were similar at baseline and did not change over time (p = 0.2 and p = 0.1, respectively). In contrast, for CD34+/KDR+/CD45- and CD34+/CD133+/CD45- cells, a significant increase with time was seen (p = 0.02 and p = 0.002, respectively) and no differential effect of either drug was seen. In conclusion, telmisartan shows a more potent anti-inflammatory effect than ramipril after an ACS. The 2 drugs do not show a differential effect on endothelial progenitor cell mobilization.

Low-molecular-weight heparins induce decidual heparin-binding epidermal growth factor-like growth factor expression and promote survival of decidual cells undergoing apoptosis.

OBJECTIVE To evaluate the effects of low-molecular-weight heparins (LMWHs) on decidual heparin-binding epidermal growth factor-like growth factor (HB-EGF) expression/secretion and on TNF-α-induced decidual apoptosis. DESIGN Experimental study. SETTING Department of Obstetrics and Gynecology, Università Cattolica del Sacro Cuore, Rome, Italy. PATIENT(S) Cultures of primary decidual cells isolated from human term placenta. INTERVENTION(S) The effects of LMWHs (tinzaparin and enoxaparin) on decidual HB-EGF expression and secretion were investigated by Western blot analysis and ELISA, respectively. TNF-α-induced decidual apoptosis was evaluated by annexin V staining, terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL) assay, and caspase activities. MAIN OUTCOME MEASURE(S) Decidual HB-EGF expression/secretion and apoptotic rate induced by TNF-α were investigated. RESULT(S) Tinzaparin enhanced decidual HB-EGF expression and secretion. TNF-α reduced the number of viable cells by inducing apoptosis. Simultaneous addition of LMWHs (primarily tinzaparin) blocked the increase in annexin V- and TUNEL-positive cells and reduced the amount of caspase activities. CONCLUSION(S) Both LMWHs induced a significant increase in decidual HB-EGF expression/secretion and reduced TNF-α-induced decidual apoptosis. Tinzaparin demonstrated higher efficacy.

Effects of Drospirenone–Ethinylestradiol and/or Metformin on CD4+CD28null T Lymphocytes Frequency in Women With Hyperinsulinemia Having Polycystic Ovary Syndrome: A Randomized Clinical Trial

Objective: To evaluate the long-term effects of drospirenone (DRSP)/ethinylestradiol (EE) alone, metformin alone, and DRSP/EE-metformin on CD4+CD28null T lymphocytes frequency, a cardiovascular risk marker, in patients with hyperinsulinemic polycystic ovary syndrome (PCOS). Design: Randomized clinical trial. Interventions: Ninety three patients with hyperinsulinemic PCOS were age matched and body mass index matched and randomized to receive a 6 months daily treatment with DRSP (3 mg)/EE (0.03 mg), or metformin (1500 mg), or DRSP/EE combined with metformin. Main Outcome Measures: CD4+CD28null T-cell frequencies. Results: The DRSP/EE and metformin groups did not show any significant change in the CD4+CD28null frequency compared to the baseline. Interestingly, a statistically significant decrease in CD4+CD28null frequency occurred after 6 months of DRSP/EE-metformin (median 3-1.5; P < .01). Of note, this statistically significant association was confirmed after adjusting for baseline values in DRSP/EE-metformin group by analysis of covariance (P < .05). Conclusions: In women with hyperinsulinemic PCOS, combined therapy with DRSP/EE and metformin may reduce cardiovascular risk.

Effects of Drospirenone–Ethinylestradiol and/or Metformin on CD4+CD28null T Lymphocytes Frequency in Women With Hyperinsulinemia Having Polycystic Ovary Syndrome

Objective: To evaluate the long-term effects of drospirenone (DRSP)/ethinylestradiol (EE) alone, metformin alone, and DRSP/EE-metformin on CD4+CD28null T lymphocytes frequency, a cardiovascular risk marker, in patients with hyperinsulinemic polycystic ovary syndrome (PCOS). Design: Randomized clinical trial. Interventions: Ninety three patients with hyperinsulinemic PCOS were age matched and body mass index matched and randomized to receive a 6 months daily treatment with DRSP (3 mg)/EE (0.03 mg), or metformin (1500 mg), or DRSP/EE combined with metformin. Main Outcome Measures: CD4+CD28null T-cell frequencies. Results: The DRSP/EE and metformin groups did not show any significant change in the CD4+CD28null frequency compared to the baseline. Interestingly, a statistically significant decrease in CD4+CD28null frequency occurred after 6 months of DRSP/EE-metformin (median 3-1.5; P < .01). Of note, this statistically significant association was confirmed after adjusting for baseline values in DRSP/EE-metformin group by analysis of covariance (P < .05). Conclusions: In women with hyperinsulinemic PCOS, combined therapy with DRSP/EE and metformin may reduce cardiovascular risk.

Peripheral levels of circulating progenitor cells correlate with area at risk and microvascular obstruction at cardiac magnetic resonance imaging in patients with ST-elevation myocardial infarction

Background Circulating progenitor cells (CPC) are bone marrowderived elements with reparative properties known to be mobilised in the context of acute coronary syndromes. Controversy persists over the determinants of their release in the acute phase of ST-elevation myocardial infarction (STEMI). We used cardiovascular magnetic resonance (CMR) to investigate this issue. Methods Fifteen STEMI patients undergoing successful primary percutaneous coronary intervention (pPCI) were included. Peripheral vein blood samples were drawn at 48 hours after pPCI to measure CPC (CD34+/ KDR +/CD45-). At 2-7 days after pPCI all patients underwent CMR assessment with SSFP, T2-STIR, first-pass perfusion and late gadolinium-enhancement imaging. Quantitative T2 area-at-risk (AAR, % of LV volume), infarct size (IS, % of LV volume), myocardial salvage (MS, calculated as AAR-IS) were calculated. Microvascular obstruction (MVO) was assessed both as perfusion defect score on first-pass imaging (PD, expressed as a sum of a 0 to 3 scoring for each of 16 LV segments) or as MVO score in the late enhancement images. Results CPC levels (expressed as %, number of cells per total number of cytometric events) were more strongly related to extent of AAR (rho=0.72, p=0.002) than to IS (rho=0.5, p=0.06), but did not correlate to MS (rho=0.002, p=0.9). Moreover, CPC were related to PD score (rho=0.54, p=0.03) but not to MVO score (rho=0.3, p=0.2). Conclusions Our data suggest that CPC are mobilized in STEMI patients in response to the total myocardial ischemic insult, as represented by the area-at-risk on T2-STIR. Furthermore, CPC positive correlation with PD suggests that they could be mobilized in attempt to overcome ongoing microvascular dysfunction.