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Objective. Stimuli activating vascular smooth muscle cell death can constrain the neointimal response to arterial damage and prevent vascular thickening. Conversely, endothelial cell death increases endothelial dysfunction and thrombosis risk. We investigated the combined effect of atorvastatin and TNF-α on vascular cell death. Methods and Results. Cell death was investigated in cultures of human aortic smooth muscle cells (VSMCs) and human umbilical vein endothelial cells (HUVECs). Atorvastatin downregulated NF-κB and enhanced JNK activity and cell death in VSMC cultured with TNF- α. In the absence of TNF-α, percentages (mean and StDev) of annexin V positive cells were 17.4± 6.6%, 19.3± 5.9%, 22.9± 9.4% and 35.0± 20.0 % with 0, 1, 3 and 10 μM atorvastatin, respectively. The cytotoxic effect of statin was significant at the highest dose of 10 μM (p=0.001). In the presence of TNF-α, percentages of annexin V positive cells were 27.1±10.6%, 34.2±8.5%, 37.4±14.6, and 54.1±20.0% with 0, 1, 3 and 10 ±M atorvastatin, respectively. The cytotoxic effect of statin was significant at each dose used (p± 0.02), in the presence of TNF-α. The cell death sensitising effect of atorvastatin was apparently mediated by down modulation of PKCβ activity, because it was reproduced by the specific PKCβ inhibitor LY317615 and prevented by the PKC activator phorbol-12-myristate-13-acetate (PMA). This effect was cell context dependent because it was not observed in HUVECs. PKCβ was found to be constitutively active in VSMCs but not in HUVECs, thereby explaining the differential effect among the two cell types. Measurement of phosphoPKCβ protein levels in arterial specimens confirmed increased activation of this kinase in the smooth muscle layer, in comparison with endothelium. We show that PKCβ provides survival signals to vascular smooth muscle cells and not the endothelium. Conclusion. Our study suggests that atorvastatin enhances TNF-α-induced cell death in vascular smooth muscle- but not endothelial – cells; by a cell-context-dependent mechanism, involving PKCβ inhibition.

BACKGROUND: Despite significant improvements in stent platform, currently available bare-metal stents (BMS) are still associated with restenosis. Thin-strut design cobalt-chromium alloys hold the promise of improving results of BMS, especially when implanted with direct technique. We performed an observational study to appraise outcomes of the novel Skylor™ stent, stratifying outcomes according to stenting technique. METHODS and RESULTS: We included all consecutive patients undergoing coronary stenting with Skylor™ at 2 centers between 2006 and 2009. The primary end-point was the long-term rate of major adverse cardiac events (MACE, i.e. death, myocardial infarction (MI), coronary artery bypass grafting (CABG) or target vessel revascularization (TVR)). As pre-specified analysis, we compared patients undergoing direct stenting versus those stent implantation following predilation. A total of 1020 patients were included (1292 Skylor™ stents), with procedural success obtained in 99%. Comparing patients undergoing direct stenting (66%) versus pre-dilation (34%) at 16±7 months of follow-up, MACE had occurred in, respectively, 8% versus 14% (p=0.001), with death in 1% versus 2% (p=0.380), MI in 1% versus 2% (p=0.032), CABG in 0.2% versus 2% (p=0.012), and TVR in 6% versus 9% [p=0.071]. Even at multivariable analysis with propensity adjustment, direct stenting was associated with significantly fewer MACE [hazard ratio 0.60 [0.38-0.93], p=0.024]. CONCLUSIONS: This observational study suggests the presence of a beneficial synergy between direct coronary stenting technique and use of the novel thin-strut cobalt-chromium Skylor™ stent in real-world patients undergoing PCI.

To evaluate the influence of the severity of regional myocardial dysfunction and of the length of follow-up on the identification of myocardial viability with rest-redistribution Tl single photon emission computed tomography (SPECT) and low-dose dobutamine echocardiography (LDDE).Twenty-six patients with chronic coronary artery disease and wall motion abnormalities, candidates for revascularization, were included in this study. All patients underwent, in the same week, Tl SPECT and LDDE for pre-revascularization evaluation of myocardial viability. Reversibility of regional dysfunction was assessed by two-dimensional echocardiography, 40+/-20 days (early follow-up) and 12+/-5 months (late follow-up) after revascularization.In a/dyskinetic segments, Tl SPECT showed similar values of sensitivity (78% vs. 71%, P=NS) and slightly higher values of specificity (43% vs. 18%, P0.01) compared to hypokinetic segments, in predicting functional recovery at early follow-up. No significant changes were observed in the diagnostic accuracy of Tl SPECT at late follow-up. On the contrary, LDDE provided significantly lower values of sensitivity (56% vs. 94%, P0.05) and higher values of specificity (73% vs. 9%, P0.01) in a/dyskinetic compared to hypokinetic segments. Specificity of LDDE in a/dyskinetic segments significantly increased from early (73%) to late follow-up (95%; P0.05). Similarly, positive predictive value in a/dyskinetic segments significantly increased from early (69%) to late follow-up (96%; P0.05).The severity of regional dysfunction and the length of follow-up significantly influence the diagnostic accuracy of LDDE but not of rest-redistribution Tl SPECT in the identification of myocardial viability.

Compelling evidence has emerged in recent years indicating that stromal cells play a critical role in disease progression. CXCR4 is a G-protein-coupled receptor with a major role in lymphocyte homing. Its ligand, CXCL12, is a highly efficient chemotactic factor for T cells, monocytes, pre-B cells, dendritic cells and myeloid bone marrow-derived cells (BMDCs). In addition, the CXCR4-CXCL12 axis plays a central role in tumor growth and metastasis. To evaluate the effect of genetic CXCR4 reduction on metastasis development, murine melanoma B16 cells were injected into the tail vein of C57BL/6 CXCR4(+/+) and CXCR4(+/-) mice in the presence of the CXCR4 inhibitor, Plerixafor (previously named AMD3100). Although lung metastases developed in wild-type CXCR4(+/+) and heterozygote CXCR4(+/-) mice, nodules were significantly smaller in the latter. CXCR4 pharmacological inhibition by Plerixafor further reduced lung metastases in CXCR4(+/-) mice, preserving the pulmonary architecture (4.18 ± 1.38 mm(2) vs. 1.11 ± 0.60 mm(2), p = 0.038). A reduction in LY6G-positive myeloid/granulocytic cells and in p38 MAPK activation was detected in lungs from CXCR4(+/-) mice compared to CXCR4(+/+) mice [LY6G-positive myeloid CXCR4(+/-) vs. CXCR4(+/+) (p = 0.0004); CXCR4(+/+) vs. CXCR4(+/+) Plerixafor-treated (p = 0.0031)] suggesting that CXCR4 reduction on myeloid-derived cells reduced their recruitment to the lung, consequently impairing lung metastases. Our findings argue in favor of a specific role of CXCR4 expressed in stromal cells that condition the pro-tumor microenvironment. In this scenario, CXCR4 antagonists will target neoplastic cells as well as the pro-tumor stromal microenvironment.

CXCR4 is a chemokine receptor implicated in the metastatic process. The CXCR4 ligand, CXCL12, was shown to bind also the CXCR7 receptor, a recently deorphanized chemokine receptor whose signalling pathway and function are still controversial. This study was conducted to determine patients clinic-pathological factors and outcome according to the expressions of CXCR4 and CXCR7 in renal cell carcinoma (RCC). CXCR4 and CXCR7 expression was evaluated in 223 RCC patients through immunohistochemistry; moreover CXCR4 and CXCR7 was detected in 49 others consecutive RCC patients trough RT- PCR. CXCR4 expression was low in 42/223 RCC (18.8%), intermediate in 71/223 (31.9%) and high in 110/223 (49.3%). CXCR7 expression was low in 44/223 RCC patients (19.8%), intermediate in 65/223 (29.1%) and high in 114/223 (51.1%). High CXCR4 and high CXCR7 expression predicted shorter disease free survival. In multivariate analysis, high CXCR4 expression (p= 0.0061), high CXCR7 (p= 0.0194) expression and the concomitant high expression of CXCR4 and CXCR7 (p= 0.0235) are independent prognosis factors. Through RT-PCR, CXCR4 was overexpressed in 36/49 and CXCR7 in 33/49 samples correlating with symptoms at diagnosis and lymph nodes status. So we can hypothesize that CXCR4 and CXCR7, singularly evaluated and in combination, are valuable prognostic factors in RCC patients.

The chemokine receptor CXCR4 and CD133, putative stem cell markers, were previously described in renal cancer (RCC). To evaluate the biological and prognostic role of CD133 and CXCR4 in RCC the expression was evaluated through qPCR and immunoblotting in human renal cancer cell lines (786-O, A498, ACHN, CAKI-1, SN12C, TK10, UO31) and patients biopsies. Renal cancer cells and surgical biopsies expressed functional CXCR4 while CD133 was not detectable. CXCR4 and CD133 expression was then evaluated in 240 renal cancer patients through immunohistochemistry. CXCR4 and CD133 were low in 19.1% and 59.6%; intermediate in 20% and 17.9%; high in 60.8% and 22.5% of the cases, respectively. CXCR4 was overexpressed in tumours (p= 0.02), while CD133 was over expressed in healthy tissues (p= 0.04). Disease free survival Kaplan Meier plots suggest that prognosis is unfavourable for patients whose primary tumours express CXCR4 (p= 0.0199) but nor CD133 (p= 0.151) neither the concomitant CXCR4-CD133 (p=0.848) high expression affected prognosis. Analysis of prognostic factors suggests that age, clinical presentation, AJCC stage and CXCR4 had a significant prognostic value at the univariate analysis. The CXCR4 predictive ability was confirmed at the multivariate analysis while no prognostic role was identified for CD133.Thus concomitant CD133 and CXCR4 evaluation is not worth in RCC patient while the CXCR4 prognostic role encourage CXCR4 antagonists as promising therapeutic option.