Basic and Translational Science Hot Line I – Vascular research / Rapid Fire – Proteinchanges: metabolism, injury and protection 157 Results: The reported PIK3CG variant, rs17398575 (risk allele A, frequency = 0.72), was nominally significantly associated with intraplaque hemorrhage (OR=1.40 [1.10-1.69 95% CI], p=0.0271) and vessel density (β=0.095 [0.0415 s.e.m.], p=0.0221). We also report another nearby variant, rs849429 (risk allele A, frequency=0.49), but uncorrelated to rs17398575, associated with intraplaque vessel density (β=-0.164 [0.0361 s.e.m.], p=6.70×10 -6 ). The SNP dependent PIK3CG mRNA expression demonstrated a differential effect in the vascular wall (p=0.783 for rs17398575; p=0.0198 for rs849429) compared to circulating mono- cytes (p=0.0261 for rs17398575; p=0.350 for rs849429). Conclusion: To our knowledge this is the first report involving the association of common genetic variants to histological plaque phenotypes. These results re- quire further replication in independent cohorts. Further research should focus on elucidating the underlying mechanisms leading to plaque vessel formation and intraplaque hemorrhage, as both have been demonstrated to associate with sec- ondary cardiovascular disease. 771 | BENCH Induction of angiogenesis and prevention of apoptosis by implantation of adipose tissue-derived mesenchymal stromal cells on VEGF-releasing PLGA microspheres: A combined growth factor therapy cell transplantation approach R. Madonna 1 , C. Montero-Menei 2 , J.-P. Karam 2 , C. Muscari 3 , M.A. Teberino 1 , R. De Caterina 1 . 1 Institute of Cardiology, "G. d’Annunzio" University, Chieti-Scalo, Italy; 2 INSERM U 1066, Laboratoire d’Ingénierie de la Vectorisation Particulaire, Université d’Angers, France, Italy; 3 Department of Biomedical and Neuromotor Sciences, University of Bologna, Italy, Italy; 1 Institute of Cardiology, "G. d’Annunzio", University, Italy, Italy Background: The success of tissue engineering implant relies on the ability of the scaffold to guide cell engraftment and vessel ingrowth in the ischemic tis- sue. Transplanted cells must be kept surviving in the harmful microenvironment to support tissue regeneration. Vascular endothelial growth factor (VEGF) is a po- tent angiogenic and anti-apoptotic factor, which may facilitate the engraftment of transplanted cells and guide angiogenesis. Aim: To realize poly(lactide-co-glycolide) (PLGA) pharmacologically active mic- rospheres (PAM) able to release VEGF and assess their ability to promote an- giogenesis and prevent apoptosis of adipose tissue-derived mesechymal stromal cells (AT-MSCs). Methods and results: Non-functionalized (empty) PAM or VEGF-loaded PAM were produced and coated with MSCs isolated from rat periepididimal AT at in- creasing cell:PAM concentrations. The release of VEGF from PAM occurred at a maximum rate of 0.7 ng/day per mg of PAM. The best ratio of adhesion was 4×10 4 cells per 0.5 mg of PAM. Cell-proliferation increased three fold after coat- ing with VEGF-loaded PAM compared withAT-MSCs alone and AT-MSCs coated on empty PAM, while the adipogenic and osteogenic differentiation of AT-MSCs was unchanged. MTT analysis and cleaved caspase-3 expression (immunoblot- ting) revealed that AT-MSCs alone, and to a higher extent the AT-MSCs coated on VEGF-loaded PAM, exhibited high resistance toward H2O2-induced apoptosis, and this effect was dependent by VEGF/Akt axis since reverted by pre-incubation with Akt inhibitor LY294002 or anti-VEGF receptor antibody (Figure 1, panel A- B). PAM-VEGF enhanced AT-MSC tubulization in a Matrigel assay as compared withAT-MSCs alone or AT-MSCscoated on empty PAM (n=3 independent exper- iments, P<0.01 vs controls, Figure 1, panel C). Figure 1 Conclusions: VEGF-loaded PAM coated with AT-MSCs may have therapeutic applications for enhancing angiogenesis and AT-MSC survival in harmful microen- vironment of post-ischemic tissues. RAPID FIRE – PROTEIN CHANGES: METABOLISM, INJURY AND PROTECTION 773 | BENCH Calpastatin overexpression favors cardiac rupture and aggravates left ventricular dysfunction in mice after myocardial infarction F. Wan 1 , E. Letavernier 2 , L. Baud 2 , A. Houssaini 1 , S. Abid 1 , E. Marcos 1 , G. Derumeaux 1 , J.-L. Dubois-Rande 1 , S. Adnot 1 , B. Gellen 1 . 1 Inserm U955, Institute Mondor of Biomedical Research (IMRB)-University Paris-Est, Creteil, France; 2 Inserm U702, Paris, France Rationale: Inhibition of calpains, ubiquitous cysteine proteases that require Ca2+ for activity, preserves left ventricular (LV) structure and function at short term post myocardial infarction (MI). However long term effects of this inhibition are still unclear. Objective: The purpose of this study was to examine the effects of calpain inhi- bition by ubiquitous calpastatin overexpression at long term post MI. Methods and results: Myocardial infarction was generated in transgenic (TG) male mice constitutively overexpressing calpastatin and wild-type (WT) controls. Acute phase mortality (<48h) was comparable between groups. All-cause mor- tality from 48h to 6w post MI was 43% in TG-MI and 20% WT-MI (log-rank P<0.05). Mortality by LV rupture was 31% in TG-MI and 11% in WT-MI (P<0.05). At 6w post MI, infarct size and LV dilation were comparable, while LV contrac- tility was reduced (+dP/dt 7635±782 vs. 9110±1292mmHg/s; P<0.05), LV end- diastolic pressure was increased (6.7±1.8 vs. 4.9±2.2mmHg, P<0.05), and wet pulmonary weight was more important (185.8±14.4 vs. 153.0±8.6mg, P<0.05) in TG-MI as compared to WT-MI survivors. At that time, remote myocardium (RM) of TG-MI showed more fibrosis (12.8±0.9 vs. 8.8±0.4% in WT-MI, P<0.01) and more cardiac myocyte hypertrophy (539.6±9.4 vs. 463.2±20.2μm 2 in WT-MI, P<0.05). To identify underlying mechanisms that might contribute to the worse outcome in TG-MI, a subgroup of animals was sacrificed 5d post MI. Infarct size was comparable between TG-MI and WT-MI. In the peri-infarct myocardium (PIM) of TG-MI mice, fibrosis was less pronounced, microvascularization was reduced, and macrophage and CD4+ T lymphocyte infiltration was impaired as compared to WT-MI (57%, P<0.01; and 79%; P<0.001, respectively). Conclusions: Calpastatin overexpression is deleterious at long term post MI with more severe LV failure and increased mortality owing to cardiac rupture. This is primarily due to an insufficiency in wound healing of the myocardium associated with reduced capillary repair, inflammatory response and extracellular matrix syn- thesis in the PIM. 774 | BENCH Blood cell NOS3 improves cardiac function in an acute murine model of myocardial ischemia/reperfusion S. Zander, A. Van De Sandt, M. Cortese-Krott, M. Stern, S. Becher, T. Rassaf, M. Kelm, M.W. Merx. Department of Medicine, Division of Cardiology, Angiology and Pneumology, Heinrich-Heine-University, Duesseldorf, Germany Purpose: Nitric oxide (NO) plays a protective role in myocardial ischemia and reperfusion (IR) and is constitutively produced within the endothelium by the iso- form 3 of NO synthase (NOS3). All blood cells subpopulations carries an active NOS3, including red blood cells as recently demonstrated by us. We hypothe- sized that circulating blood cell NOS3 exert a protective role in an acute murine model of myocardial ischemia/reperfusion. Methods: To analyze the role of blood cell NOS3 expression in an acute model of myocardial I/R, we generated chimera mice carrying NOS3 in blood cells (BC) only but not within the endothelium (EC) by transplanting the bone marrow of WT mice into irradiated NOS3-/- mice (BC+/EC-). Viceversa, mice lacking blood cell NOS3 only were created by transplanting bone marrow from NOS3-/- mice into irradiated WT mice (BC-/EC+). WT bone marrow transplantation into WT mice (BC+/EC+) or NOS3-/- bone marrow transplantation into NOS3-/- (BC-/EC- ) were applied to generate the respective controls. All four groups underwent a 60-minute coronary occlusion in a closed-chest model of myocardial I/R. After 24 hours of reperfusion cardiac function was assessed via high-resolution echocar- diography (Vevo 2100, VisualSonics). Blood pressure was measured invasively using a pressure catheter. To analyze area at risk (AAR) and infarct size (IS), 2,3,5-Triphenyltetrazolium chloride (TTC) staining was applied. The levels of NO metabolites in plasma and heart tissue were measured by high pressure liquid chromatography. Results: After 24 hours of reperfusion systolic left ventricular function was impaired with reduced ejection fraction and increased endsystolic volume in BC-/EC+ compared to BC+/EC+ and BC-/EC- compared to BC+/EC-. In BC- /EC+ infarct sizes were significantly increased compared to BC+/EC+ (BC-/EC+: 26,59±6,98% vs. BC+/EC+: 14,22±5,31%, p< 0,01, n= 6-9 per group). Similarly, in BC-/EC- infarct size was significantly increased compared to BC+/EC- (BC- /EC-: 26,97±5,13% vs. BC+/EC-: 20,54±5,25%, p<0,05, n=6-10 per group, AAR per LV did not differ between the groups). Blood pressure was progressively ele- vated in BC-/EC+, BC+/EC- and BC-/EC- compared to BC+/EC+, while BC-/EC- exhibited the maximum blood pressure of the four types of chimera generated. Ni- trite and nitrate levels were reduced in BC-/EC+ plasma at baseline and 24 hours of reperfusion compared to BC+/EC+. Conclusion: Reduced infarct size, preserved cardiovascular function and im- Downloaded from https://academic.oup.com/eurheartj/article-abstract/34/suppl_1/771/2860236 by guest on 11 June 2020