A. Ghashghai

Epidermal Growth Factor–Like Domain 7 Is a Novel Inhibitor of Neutrophil Adhesion to Coronary Artery Endothelial Cells Injured by Calcineurin Inhibition

Background— We investigated the effect of epidermal growth factor–like domain 7 (Egfl7) on nuclear factor-&kgr;B activation, intercellular adhesion molecule-1 expression, and neutrophil adhesion to human coronary artery endothelial cells after calcineurin-inhibition–induced injury. Methods and Results— Human coronary endothelial cells were incubated with cyclosporine (CyA) 10 &mgr;g/mL with or without Egfl7 (100 ng/mL) or the Notch receptor activator Jagged1 (200 ng/mL) for 6 to 48 hours. CyA upregulated nuclear factor-&kgr;B (p65) activity (128±2% of control, P<0.001) in nuclear extracts, as determined with a DNA-binding activity ELISA. This activity was inhibited by Egfl7 (86±3% of control; P<0.001 versus CyA alone). Jagged1 blocked Egfl7-induced nuclear factor-&kgr;B inhibition (105±4% of control; P<0.05 versus CyA plus Egfl7). CyA upregulated cell-surface intercellular adhesion molecule-1 expression (215±13% of control; P<0.001), as determined by flow cytometry. This expression was suppressed by Egfl7 (148±5%; P<0.001 versus CyA alone). Jagged1 attenuated the intercellular adhesion molecule-1–suppressive effect of Egfl7 when administered with CyA (193±3% versus 148±5%; P<0.01). CyA increased neutrophil adhesion to human coronary endothelial cells (control 20±5%, CyA 37±3%; P<0.001 versus control) in a nonstatic neutrophil adhesion assay. This increase was attenuated by Egfl7 (22±6%; P<0.001 versus CyA alone). Jagged 1 attenuated the effect of Egfl7 on neutrophil adhesion (31±3%; P<0.001 versus Egfl7 plus CyA). Conclusions— Our study reveals that Egfl7 is a potent inhibitor of neutrophil adhesion to human coronary endothelial cells subsequent to calcineurin-inhibition–induced injury. Mechanistically, Egfl7 blocked nuclear factor-&kgr;B pathway activation and intercellular adhesion molecule-1 expression, which suggests that it may have significant antiinflammatory properties. Because Jagged1 blocked the effect of Egfl7, Notch receptor antagonism may contribute to the mechanism of action of Egfl7.

Markers of inflammation in recipients of continuous-flow left ventricular assist devices.

Although the newer continuous-flow left ventricular assist devices (CF-LVADs) provide clinical advantages over the pulsatile pumps, the effects of low pulsatility on inflammation are incompletely understood. The objective of our study was to examine the levels of inflammatory mediators in CF-LVAD recipients compared with both healthy control subjects and heart failure patients who were candidates for CF-LVAD support. Plasma levels of chemokines, cytokines, and inflammatory markers were measured in 18 CF-LVAD recipients and compared with those of 14 healthy control subjects and 14 heart failure patients who were candidates for CF-LVADs. The levels of granulocyte macrophage-colony stimulating factor, macrophage inflammatory proteins-1&bgr;, and macrophage-derived chemokine were significantly higher in the CF-LVAD group compared with both the heart failure and the healthy control groups, whereas no significant differences were observed between the healthy control subjects and the heart failure groups. Compared with the healthy controls, C-reactive protein, interferon gamma-induced protein-10, monocyte chemotactic protein-1, and interleukin-8 levels were significantly higher in both the CF-LVAD and heart failure groups, but no significant differences were observed between the CF-LVAD recipients and the heart failure patients. Inflammatory markers were elevated in CF-LVAD recipients compared with healthy control subjects and the heart failure patients. Further studies should investigate the clinical implications of elevated levels of inflammation in CF-LVAD recipients.

Longitudinal Assessment of Inflammation in Recipients of Continuous-Flow Left Ventricular Assist Devices

BACKGROUND The long-term effects of continuous-flow left ventricular assist device (CF-LVAD) support on trends of inflammatory markers over time are unknown. We examined the hypothesis that the levels of inflammatory markers in CF-LVAD recipients are higher than in healthy controls and that these levels increase over time with long-term CF-LVAD support. METHODS We examined the levels of inflammatory markers longitudinally at baseline before CF-LVAD implantation and at 3, 6, and 9 months after implantation. We then compared the levels of inflammatory markers to those in a healthy control group. RESULTS Compared with baseline values before CF-LVAD implantation, left ventricular end-diastolic diameter (LVEDd) and left ventricular end-systolic diameter (LVESd) decreased significantly at 3, 6, and 9 months after CF-LVAD implantation. Brain natriuretic peptide (BNP) levels dropped significantly after CF-LVAD implantation but did not normalize. Improvements in ejection fraction at 3, 6, and 9 months after CF-LVAD implantation did not reach significance. Monocyte chemoattractant protein-1, interferon γ-induced protein, and C-reactive protein levels were higher in the CF-LVAD recipients at each of the time points (baseline before CF-LVAD implantation and 3, 6, and 9 months after implantation) compared with levels in healthy controls. In CF-LVAD recipients, serum interleukin-8, tumour necrosis factor-α, and macrophage inflammatory protein-β increased significantly at 9 months, and macrophage-derived chemokine increased at 6 months after CF-LVAD implantation compared with baseline. CONCLUSIONS Despite improvements in LV dimensions and BNP levels, markers of inflammation remained higher in CF-LVAD recipients. High levels of inflammation in CF-LVAD recipients may result from heart failure preconditioning or the long-term device support, or both. Because inflammation may be detrimental to CF-LVAD recipients, future studies should determine whether inflammatory pathways are reversible.

TERT-BUTYLHYDROQUINONE RESCUES CYCLOSPORINE-A MEDIATED IMPAIRMENT IN VASCULAR FUNCTION VIA AUGMENTING PHOSPHORYLATION OF THE TRANSCRIPTION FACTOR NRF2

Background: Oxidative stress mediates cyclosporine-A (CsA) associated vascular injury post-cardiac transplantation. We investigated the effect of CsA on the Nrf2 pathway by examining vascular function, Nrf2 phosphorylation and superoxide dismutase (SOD) activity and the ability of tBHQ to rescue CsA-mediated injury. Methods and Results: Lewis rats received tBHQ (50mg/kg), CsA (5mg/kg) ± tBHQ, or Saline (CON). Thoracic aortic segments were assessed for vascular function as measured by endothelial-dependent (Edep) relaxation (ED50), and sensitivity to endothelin-1 (ET-1) vasoconstriction. We also analyzed Nrf2 protein expression, phospho-Nrf2/Nrf2 ratio, and SOD activity. CsA significantly impaired Edep vasorelaxation (ED50: 3.5x10-8 +/- 0.4M vs CON 1.8x10-8 +/- 0.5M, p<0.001). tBHQ did not affect vasorelaxation compared to CON (2.18x10-8 +/- 0.4M, p=NS). However, tBHQ improved vasorelaxation in CsA-treated rats significantly (ED50: 2.69x10-8 +/- 0.3M vs CsA alone, p<0.001). Compared to CON, CsA exposure demonstrated increased sensitivity to ET-1 vasospasm (CsA ED50 1.9x10-9 +/- 0.1M vs 2.85x10-9 +/- 0.4M CON, p<0.001) which was rescued significantly by tBHQ exposure compared to CsA alone (ED50: 2.55x10-9 +/- 0.5M). tBHQ alone did not affect sensitivity to ET-1 vasospasm compared to CON (ED50: 2.65x10-9 +/- 0.3M, p=NS). CsA treatment resulted in decreased Nrf2 expression, phosphorylation, and SOD activity (Fig1). Exposure to tBHQ rescued CsA-mediated Nrf2 downregulation, and reduction in Nrf2 phosphorylation and SOD activity (Fig1). Conclusions: Our study suggests potential therapeutic strategies to prevent coronary vascular dysfunction as combined therapy with tBHQ completely abrogated CsA-induced impairment of Nrf2- signalling and vascular injury. Mechanistically, tBHQ may act to rescue Nrf2 expression, phosphorylation and SOD activity in order to ameliorate CsA-mediated coronary dysfunction. ![][1] [1]: /embed/graphic-1.gif