Recombinant human soluble domain of CD39L3 and ticagrelor: cardioprotective effects in experimental myocardial infarction.

BACKGROUND AND AIMS: The ecto-nucleoside triphosphate diphosphohydrolases of the CD39 family degrade ATP and ADP into AMP, which is converted into adenosine by the extracellular CD73/ecto-5-nucleotidase. This pathway has been explored in antithrombotic treatments but little in myocardial protection. We have investigated whether the administration of solCD39L3 (AZD3366) confers additional cardioprotection to that of ticagrelor alone in a pre-clinical model of myocardial infarction (MI). METHODS: Ticagrelor-treated pigs underwent balloon-induced MI (90 min) and, before reperfusion, received intravenously either vehicle, 1 mg/kg AZD3366 or 3 mg/kg AZD3366. All animals received ticagrelor twice daily for 42 days. A non-treated MI group was run as a control. Serial cardiac magnetic resonance (baseline, Day 3 and Day 42 post-MI), light transmittance aggregometry, bleeding time, and histological and molecular analyses were performed. RESULTS: Ticagrelor reduced oedema formation and infarct size at Day 3 post-MI vs. controls. A 3 mg/kg AZD3366 provided an additional 45% reduction in oedema and infarct size compared with ticagrelor and a 70% reduction vs. controls (P < .05). At Day 42, infarct size declined in all ticagrelor-administered pigs, particularly in 3 mg/kg AZD3366-treated pigs (P < .05). Left ventricular ejection fraction was diminished at Day 3 in placebo pigs and worsened at Day 42, whereas it remained unaltered in ticagrelor ± AZD3366-administered animals. Pigs administered with 3 mg/kg AZD3366 displayed higher left ventricular ejection fraction upon dobutamine stress at Day 3 and minimal dysfunctional segmental contraction at Day 42 (χ2P < .05 vs. all). Cardiac and systemic molecular readouts supported these benefits. Interestingly, AZD3366 abolished ADP-induced light transmittance aggregometry without affecting bleeding time. CONCLUSIONS: Infusion of AZD3366 on top of ticagrelor leads to enhanced cardioprotection compared with ticagrelor alone.

A comprehensive and longitudinal cardiac magnetic resonance imaging study of the impact of coronary ischemia duration on myocardial damage in a highly translatable animal model.

OBJECTIVES: We performed a comprehensive assessment of the effect of myocardial ischemia duration on cardiac structural and functional parameters by serial cardiac magnetic resonance (CMR) and characterized the evolving scar. BACKGROUND: CMR follow-up on the cardiac impact of time of ischemia in a closed-chest animal model of myocardial infarction with human resemblance is missing. METHODS: Pigs underwent MI induction by occlusion of the left anterior descending (LAD) coronary artery for 30, 60, 90 or 120 min and then revascularized. Serial CMR was performed on day 3 and day 42 post-MI. CMR measurements were also run in a sham-operated group. Cellular and molecular changes were investigated. RESULTS: On day 3, cardiac damage and function were similar in sham and pigs subjected to 30 min of ischemia. Cardiac damage (oedema and necrosis) significantly increased from 60 min onwards. Microvascular obstruction was extensively seen in animals with ≥90 min of ischemia and correlated with cardiac damage. A drop in global systolic function and wall motion of the jeopardized segments was seen in pigs subjected to ≥60 min of ischemia. On day 42, scar size and cardiac dysfunction followed the same pattern in the animals subjected to ≥60 min of ischemia. Adverse left ventricular remodelling (worsening of both LV volumes) was only present in animals subjected to 120 min of ischemia. Cardiac fibrosis, myocyte hypertrophy and vessel rarefaction were similar in the infarcted myocardium of pigs subjected to ≥60 min of ischemia. No changes were observed in the remote myocardium. CONCLUSION: Sixty-minute LAD coronary occlusion already induces cardiac structural and functional alterations with longer ischemic time (120 min) causing adverse LV remodelling.

Differential cholesterol uptake in liver cells: A role for PCSK9.

The clearance of low-density lipoprotein (LDL) particles from the circulation is regulated by the LDL receptor (LDLR) and proprotein convertase subtilisin/kexin 9 (PCSK9) interaction. Its disruption reduces blood cholesterol levels and delays atherosclerosis progression. Whether other members of the LDLR superfamily are in vivo targets of PCSK9 has been poorly explored. The aim of this work was to study the interaction between PCSK9 and members of the LDLR superfamily in the regulation of liver cholesterol homeostasis in an in vivo low-density lipoprotein receptor related protein 5 (LRP5) deficient mice model challenged with high-fat diet. Our results show that Wt and Lrp5-/- mice fed a hypercholesterolemic diet (HC) have increased cholesterol ester accumulation and decreased liver LDLR and LRP5 gene and protein expression. Very low-density lipoprotein receptor (VLDLR), LRP6, LRP2, and LRP1 expression levels were analyzed in liver samples and show that they do not participate in Lrp5-/- liver cholesterol uptake. Immunoprecipitation experiments show that LRP5 forms a complex with PCSK9 in liver-specific fat-storing stellate cells but not in structural HepG2 cells. Hepatic stellate cells silenced for LRP5 and/or PCSK9 expression and challenged with lipids show reduced cholesterol ester accumulation, indicating that both proteins are involved in lipid processing in the liver. Our results indicate that cholesterol esters accumulate in livers of Wt mice in a LDLR-family-members dependent manner as VLDLR, LRP2, and LRP6 show increased expression in HC mice. However, this increase is lost in livers of Lrp5-/- mice, where scavenger receptors are involved in cholesterol uptake. PCSK9 expression is strongly downregulated in mice livers after HC feeding. However PCSK9 and LRP5 bind in the cytoplasm of fat storing liver cells, indicating that this PCSK9-LRP5 interaction is cell-type specific and that both proteins contribute to lipid uptake.

Hypercholesterolemia-Induced HDL Dysfunction Can Be Reversed: The Impact of Diet and Statin Treatment in a Preclinical Animal Model.

High-density lipoproteins (HDL) undergo adverse remodeling and loss of function in the presence of comorbidities. We assessed the potential of lipid-lowering approaches (diet and rosuvastatin) to rescue hypercholesterolemia-induced HDL dysfunction. Hypercholesterolemia was induced in 32 pigs for 10 days. Then, they randomly received one of the 30-day interventions: (I) hypercholesterolemic (HC) diet; (II) HC diet + rosuvastatin; (III) normocholesterolemic (NC) diet; (IV) NC diet + rosuvastatin. We determined cholesterol efflux capacity (CEC), antioxidant potential, HDL particle number, HDL apolipoprotein content, LDL oxidation, and lipid levels. Hypercholesterolemia time-dependently impaired HDL function (−62% CEC, −11% antioxidant index (AOI); p < 0.01), increased HDL particles numbers 2.8-fold (p < 0.0001), reduced HDL-bound APOM (−23%; p < 0.0001), and increased LDL oxidation 1.7-fold (p < 0.0001). These parameters remained unchanged in animals on HC diet alone up to day 40, while AOI deteriorated up to day 25 (−30%). The switch to NC diet reversed HDL dysfunction, restored apolipoprotein M content and particle numbers, and normalized cholesterol levels at day 40. Rosuvastatin improved HDL, AOI, and apolipoprotein M content. Apolipoprotein A-I and apolipoprotein C-III remained unchanged. Lowering LDL-C levels with a low-fat diet rescues HDL CEC and antioxidant potential, while the addition of rosuvastatin enhances HDL antioxidant capacity in a pig model of hypercholesterolemia. Both strategies restore HDL-bound apolipoprotein M content.

HDL (High-Density Lipoprotein) Remodeling and Magnetic Resonance Imaging-Assessed Atherosclerotic Plaque Burden: Study in a Preclinical Experimental Model.

OBJECTIVE: HDL (high-density lipoprotein) role in atherosclerosis is controversial. Clinical trials with CETP (cholesterylester transfer protein)-inhibitors have not provided benefit. We have shown that HDL remodeling in hypercholesterolemia reduces HDL cardioprotective potential. We aimed to assess whether hypercholesterolemia affects HDL-induced atherosclerotic plaque regression. Approach and Results: Atherosclerosis was induced in New Zealand White rabbits for 3-months by combining a high-fat-diet and double-balloon aortic denudation. Then, animals underwent magnetic resonance imaging (basal plaque) and randomized to receive 4 IV infusions (1 infusion/wk) of HDL isolated from normocholesterolemic (NC-HDL; 75 mg/kg; n=10), hypercholesterolemic (HC-HDL; 75 mg/Kg; n=10), or vehicle (n=10) rabbits. Then, animals underwent a second magnetic resonance imaging (end plaque). Blood, aorta, and liver samples were obtained for analyses. Follow-up magnetic resonance imaging revealed that NC-HDL administration regressed atherosclerotic lesions by 4.3%, whereas, conversely, the administration of HC-HDLs induced a further 6.5% progression (P<0.05 versus basal). Plaque characterization showed that HC-HDL administered animals had a 2-fold higher lipid and cholesterol content versus those infused NC-HDL and vehicle (P<0.05). No differences were observed among groups in CD31 levels, nor in infiltrated macrophages or smooth muscle cells. Plaques from HC-HDL administered animals exhibited higher Casp3 (caspase 3) content (P<0.05 versus vehicle and NC-HDL) whereas plaques from NC-HDL infused animals showed lower expression of Casp3, Cox1 (cyclooxygenase 1), inducible nitric oxide synthase, and MMP (metalloproteinase) activity (P<0.05 versus HC-HDL and vehicle). HDLs isolated from animals administered HC-HDL displayed lower antioxidant potential and cholesterol efflux capacity as compared with HDLs isolated from NC-HDL-infused animal and vehicle or donor HDL (P<0.05). There were no differences in HDL-ApoA1 content, ABCA1 (ATP-binding cassette transporter A1) vascular expression, and SRB1 (scavenger receptor B1) and ABCA1 liver expression. CONCLUSIONS: HDL particles isolated from a hypercholesterolemic milieu lose their ability to regress and stabilize atherosclerotic lesions. Our data suggest that HDL remodeling in patients with co-morbidities may lead to the loss of HDL atheroprotective functions.

Molecular pathways involved in the cardioprotective effects of intravenous statin administration during ischemia.

The success of therapies targeting myocardial reperfusion injury is limited, while the cardioprotective impact of mitigating ischemia-related damage remains less explored. We have recently shown in a pig model that the intravenous administration of a modified atorvastatin preparation during ischemia attenuates the rise of cardiac ischemia injury biomarkers. In the following study, we sought to investigate the mechanisms behind these ischemia-related cardioprotective effects. Ischemia was induced by 90 min total coronary balloon occlusion in pigs fed a normocholesterolemic regime. Fifteen minutes after the onset of ischemia, animals were randomized to receive intravenous atorvastatin preparation (IV-atorva) or vehicle. After ischemia animals were euthanized to assess the effect of IV-atorva treatment on gene and protein levels/activation of senescence-, apoptosis-, and cardioprotective/metabolic-related markers. Proof-of-concept studies were carried out in mice and rats in which treatments or vehicle were administered 15 min after initiation of ischemia induced by permanent coronary ligation. Western-blot analyses revealed that in the ischemic myocardium of IV-atorva-treated pigs, RhoA was inactivated, phosphorylation of p53 and caspase-3 was reduced and AMPK was activated with the consequent regulation of the mTOR/raptor-signaling pathway. IV-atorva-treated rats showed, as compared to vehicle, a significant reduction (60%) in scar size assessed at 1 month by histological staining, and mice studies demonstrated the causal involvement of AMPK activation in IV-atorva mediated cardioprotective effects. We demonstrate in pigs and rodents that prompt intravenous treatment with atorvastatin during ischemia limits cardiac cell death and reduces infarct size through AMPK signaling.

Protective Effects of Ticagrelor on Myocardial Injury After Infarction.

BACKGROUND: The P2Y12 receptor antagonist ticagrelor has been shown to be clinically superior to clopidogrel. Although the underlying mechanisms remain elusive, ticagrelor may exert off-target effects through adenosine-related mechanisms. We aimed to investigate whether ticagrelor reduces myocardial injury to a greater extent than clopidogrel after myocardial infarction (MI) at a similar level of platelet inhibition and to determine the underlying mechanisms. METHODS: Pigs received the following before MI induction: (1) placebo-control; (2) a loading dose of clopidogrel (600 mg); (3) a loading dose of ticagrelor (180 mg); or (4) a loading dose of ticagrelor followed by an adenosine A1/A2-receptor antagonist [8-(p-sulfophenyl)theophylline, 4 mg/kg intravenous] to determine the potential contribution of adenosine in ticagrelor-related cardioprotection. Animals received the corresponding maintenance doses of the antiplatelet agents during the following 24 hours and underwent 3T-cardiac MRI analysis. Platelet inhibition was monitored by ADP-induced platelet aggregation. In the myocardium, we assessed the expression and activation of proteins known to modulate edema formation, including aquaporin-4 and AMP-activated protein kinase and its downstream effectors CD36 and endothelial nitric oxide synthase and cyclooxygenase-2 activity. RESULTS: Clopidogrel and ticagrelor exerted a high and consistent antiplatelet effect (68.2% and 62.2% of platelet inhibition, respectively, on challenge with 20 µmol/L ADP) that persisted up to 24 hours post-MI (P<0.05). All groups showed comparable myocardial area-at-risk and cardiac worsening after MI induction. 3T-Cardiac MRI analysis revealed that clopidogrel- and ticagrelor-treated animals had a significantly smaller extent of MI than placebo-control animals (15.7 g left ventricle and 12.0 g left ventricle versus 22.8 g left ventricle, respectively). Yet, ticagrelor reduced infarct size to a significantly greater extent than clopidogrel (further 23.5% reduction; P=0.0026), an effect supported by troponin-I assessment and histopathologic analysis (P=0.0021). Furthermore, in comparison with clopidogrel, ticagrelor significantly diminished myocardial edema by 24.5% (P=0.004), which correlated with infarct mass (r=0.73; P<0.001). 8-(p-Sulfophenyl)theophylline administration abolished the cardioprotective effects of ticagrelor over clopidogrel. At a molecular level, aquaporin-4 expression decreased and the expression and activation of AMP-activated protein kinase signaling and cyclooxygenase-2 increased in the ischemic myocardium of ticagrelor- versus clopidogrel-treated animals (P<0.05). These protein changes were not observed in those animals administered the adenosine receptor blocker 8-(p-sulfophenyl)theophylline. CONCLUSIONS: Ticagrelor, beyond its antiplatelet efficacy, exerts cardioprotective effects by reducing necrotic injury and edema formation via adenosine-dependent mechanisms.

Roflumilast-induced Local Vascular Injury Is Associated with a Coordinated Proteome and Microparticle Change in the Systemic Circulation in Pigs.

Drug-induced vascular injury (DIVI) is commonly associated with phosphodiesterase (PDE) inhibitors. Despite histological characterization, qualified biomarkers for DIVI detection are lacking. We investigated whether a single administration of roflumilast (PDE-IV inhibitor) induces vascular damage and identified novel surrogate biomarkers of acute vascular injury. Pigs received postoperative 250, 375, or 500 µg of roflumilast or placebo/control. After 1.5 hr, coronary reactivity was determined by catheter-based administration of acetylcholine and sodium nitroprusside (SNP) in the coronary sinus. Immunohistochemical analysis of vessel integrity (von Willebrand factor [vWF]) and fibrin(ogen) deposition was performed in the coronary artery and aorta. Peripheral blood was collected for differential proteomics and microparticles analysis. Circulating interleukin (IL)-6 was analyzed. Roflumilast-treated animals displayed higher vasodilation to acetylcholine and SNP versus controls (p < .05). Roflumilast-treated animals showed a dose-dependent (p < .05) decrease in vessel integrity and dose-dependent increase in fibrin deposition forming a continuous layer at roflumilast-500 µg. Peripheral blood of roflumilast-500-µg-treated animals showed increased levels of total and endothelial-derived microparticles and exhibited a coordinated change in proteins kininogen-1, endothelin-1, gelsolin, apolipoprotein A-I, and apolipoprotein-J associated with vascular injury (p < .05 vs. controls). IL-6 remained unaltered. Roflumilast-induced vascular injury can be detected by novel markers in peripheral blood. Validation of these surrogate markers in human samples seems required.

Beer elicits vasculoprotective effects through Akt/eNOS activation.

BACKGROUND: There is controversy regarding the effect of alcohol beverage intake in vascular vasodilatory function in peripheral arteries. The effects of beer intake in coronary vasodilation remain unknown. We investigated whether regular beer intake (alcohol and alcohol-free) protects against hypercholesterolaemia-induced coronary endothelial dysfunction and the mechanisms behind this effect. MATERIALS AND METHODS: Pigs were fed 10 days: (i) a Western-type hypercholesterolaemic diet (WD); (ii) WD+low-dose beer (12·5 g alcohol/day); (iii) WD+moderate-dose beer (25 g alcohol/day); or (iv) WD+moderate-dose alcohol-free-beer (0·0 g alcohol/day). Coronary responses to endothelium-dependent vasoactive drugs (acetylcholine: receptor mediated; calcium ionophore-A23189: nonreceptor mediated), endothelium-independent vasoactive drug (SNP) and L-NMMA (NOS-antagonist) were evaluated in the LAD coronary artery by flow Doppler. Coronary Akt/eNOS activation, MCP-1 expression, oxidative DNA damage and superoxide production were assessed. Lipid profile, lipoproteins resistance to oxidation and urinary isoxanthohumol concentration were evaluated. RESULTS: Alcoholic and nonalcoholic beer intake prevented WD-induced impairment of receptor- and non-receptor-operated endothelial-dependent coronary vasodilation. All animals displayed a similar vasodilatory response to SNP and L-NMMA blunted all endothelial-dependent vasorelaxation responses. Haemodynamic parameters remained unchanged. Coronary arteries showed lower DNA damage and increased Akt/eNOS axis activation in beer-fed animals. Animals taking beer showed HDL with higher antioxidant capacity, higher LDL resistance to oxidation and increased isoxanthohumol levels. Weight, lipids levels, liver enzymes and MCP-1 expression were not affected by beer intake. CONCLUSIONS: Non-alcoholic-related beer components protect against hyperlipemia-induced coronary endothelial dysfunction by counteracting vascular oxidative damage and preserving the Akt/eNOS pathway. Light-to-moderate beer consumption prevents and/or reduces the endothelial dysfunction associated with cardiovascular risk factors.

Reperfusion-triggered stress protein response in the myocardium is blocked by post-conditioning. Systems biology pathway analysis highlights the key role of the canonical aryl-hydrocarbon receptor pathway.

AIMS: Ischaemic post-conditioning (IPost-Co) exerts cardioprotection by diminishing ischaemia/reperfusion injury. Yet, the mechanisms involved in such protection remain largely unknown. We have investigated the effects of IPost-Co in cardiac cells and in heart performance using molecular, proteomic and functional approaches. METHODS AND RESULTS: Pigs underwent 1.5 h mid-left anterior descending balloon occlusion and then were sacrificed without reperfusion (ischaemia; n= 7), subjected to 2.5 h of cardiac reperfusion and sacrificed (n= 5); or subjected to IPost-Co before reperfusion and sacrificed 0.5 h (n= 4) and 2.5 h (n= 5) afterwards. A sham-operated group was included (n= 4). Ischaemic and non-ischaemic myocardium was obtained for molecular/histological analysis. Proteomic analysis was performed by two-dimensional electrophoresis followed by matrix-assisted laser desorption/ionization-time-of-flight identification. Potential protein networks involved were identified by bioinformatics and Ingenuity Pathway Analysis (IPA). Cardiac function was assessed by echocardiography. IPost-Co diminished (up to 2.5 h) reperfusion-induced apoptosis of both the intrinsic and extrinsic pathways whereas it did not affect reperfusion-induced Akt/mammalian target of rapamycin (mTOR)/P70S6K activation. Proteomic studies showed that IPost-Co reverted 43% of cardiac cytoplasmic protein changes observed during ischaemia and ischaemia + reperfusion. Systems biology assessment revealed significant changes in the aryl-hydrocarbon receptor (AhR) pathway (cell damage related). Bioinformatic data were confirmed since the expression of HSP90, AhR, ANRT, and ß-tubulin (involved in AhR-signalling transduction) were accordingly modified after IPost-Co. IPost-Co rescued 52% of the left ventricle-at-risk compared with reperfusion alone and resulted in a ≈30% relative improvement in left ventricular ejection fraction (P <0.05). CONCLUSION: IPost-Co improves cardiac function post-myocardial infarction and reduces reperfusion-induced cell damage by down-regulation of the AhR-signalling transduction pathway ultimately leading to infarct size reduction.

Intake of fermented beverages protect against acute myocardial injury: target organ cardiac effects and vasculoprotective effects.

Mild-to-moderate alcohol consumption has been associated with reduced risk of morbi/mortality from coronary artery disease. However, whether beer intake affords cardioprotection remains unclear. We investigated whether beer intake (alcohol-containing and alcohol-free brew) provides cardioprotection in a pig model of myocardial infarction (MI). Pigs were randomly assigned to: (1) be fed for 10 days a high-cholesterol diet (HC); (2) HC + low-dose beer (LB; 12.5 g alcohol/day); (3) HC + moderate-dose beer (MB; 25 g alcohol/day); or IV) HC + alcohol-free-MB (0.0 g alcohol/day) before MI induction and kept 21 days with the same regime. Scar size, echocardiography, biochemical and oxidative parameters were assessed. Myocardial tissue was obtained for molecular analysis and histology. All beer-fed animals were less prone to arrhythmogenesis during ischemia. At sacrifice, beer intake was associated with lower oxidative stress and higher HDL-antioxidant capacity. Within the ischemic myocardium beer-fed animals showed higher Akt/eNOS and AMPK activation and reduced sirtuin1-related apoptosis. Compared to controls beer intake was associated with lower lipid infiltration, higher TGFß-related collagen fibril formation and diminished MMP9 activity in the fibrous tissue limiting scar size (HC + LB and HC + MB P < 0.05 and HC + alcohol-free-MB P = 0.068 vs. HC). Systolic-related parameters were similarly worsen post-MI in all groups and further deteriorated in control animals (P ≤ 0.05 vs. post-MI). At sacrifice, all animals showed a worsening in diastolic-related parameters but overall cardiac performance was improved in beer-fed animals regardless of the dose or alcohol content (P ≤ 0.05). In conclusion, beer intake reduces oxidative stress and apoptosis, activates RISK components and favors reparative fibrosis improving global cardiac performance.

Supplementation With Spirulina Reduces Infarct Size and Ameliorates Cardiac Function in a Pig Model of STEMI.

Background and Aims: Myocardial infarction (MI) is the clinical manifestation of atherosclerotic coronary artery disease. Spirulina is an algae known to ameliorate cardiometabolic disorders and with proven anti-inflammatory and anti-oxidant effects. We investigated, in a highly translatable animal model, whether oral supplementation with spirulina protects against the deleterious effects triggered by ST-elevation MI (STEMI). Methods: Pigs were fed a regular diet supplemented with spirulina (1 g/animal/bid) or placebo-control for 10 days. Thereafter, animals were subjected to 1.5 h percutaneous balloon-induced coronary occlusion (STEMI) followed by 2.5 h reperfusion and then sacrificed. We assessed infarct size and cardiac function. Blood samples and infarcted and remote myocardial tissue were obtained. Results: Spirulina supplementation reduced infarct size by 64%, increased myocardial salvage by 18%, and improved cardiac function by 30% vs. controls (p < 0.05). These benefits were associated with attenuation in DNA-oxidative damage and apoptotic markers and increased iNOS in the infarcted myocardium, higher AMPK activation in the remote myocardium, and lower myocardial MCP-1 expression. Systemically, spirulina attenuated Cox-2 expression in STEMI-activated peripheral blood mononuclear cells and enhanced TNF-α release acutely post-STEMI. Additionally, spirulina decreased weight gain progression over time (p < 0.05) without changes in lipids, glucose, liver or kidney parameters. Conclusion: A 10-day supplementation with spirulina exerts cardioprotection in a preclinical setting of STEMI by limiting cardiac damage and improving ventricular contractility through anti-oxidative, anti-inflammatory, and anti-apoptotic mechanisms.

Comparison of a human acellular dermal matrix and a polypropylene mesh for pelvic floor reconstruction: a randomized trial study in a rabbit model.

Non-absorbable polypropylene (PP) meshes have been widely used in surgical reconstruction of the pelvic floor disorders. However, they are associated with serious complications. Human acellular dermal matrices (hADM) have demonstrated safety and efficacy in reconstructive medicine, but their suitability and efficacy at vaginal level is not known. This study compares the biological performance of PP mesh and a newly developed hADM. 20 rabbits were randomized to receive the hADM graft or the PP mesh. Grafts were surgically implanted in the abdominal wall and vagina. After 180 days, grafts were explanted and evaluated. The vaginal mesh extrusion rate was higher in the PP group (33% vs. 0%, p = 0.015). Full integration of the vaginal grafts was more frequent in the hADM group, where 35% of the grafts were difficult to recognize. In the PP group, the vaginal mesh was identified in 100% of the animals (p = 0.014). In PP group, the infiltrates had a focal distribution and were mostly located in the internal part of the epithelium, while in the hADM group, the infiltrates had a diffuse distribution. Additionally, the hADM group also presented more B-lymphocytes and less T-lymphocytes. Biomechanical analysis showed that hADM had lower resistance to stress. Moreover, PP mesh stiffness and elasticity were higher. Then, hADM is associated with fewer clinical complications, as well as better tissue integration. However, it shows greater incorporation into the surrounding native tissue, especially in the vaginal location, undergoing a reduction in its biomechanical properties 6 months after implantation.

Molecular and cellular mechanisms involved in cardiac remodeling after acute myocardial infarction.

The extent of cardiac remodeling determines survival after acute MI. However, the mechanisms driving cardiac remodeling remain unknown. We examined the effect of ischemia and reperfusion (R) on myocardial changes up to 6 days post-MI. Pigs underwent 1.5h or 4h mid-LAD balloon occlusion and sacrificed or 1.5h occlusion followed by R and sacrificed at 2.5h, 1 day, 3 days, and 6 days. Ischemic- (IM) and non-ischemic myocardium (NIM) was obtained for molecular analysis of: 1) apoptosis (P-Bcl2, Bax, P-p53, active-caspase-3); 2) the TLR-4-MyD88-dependent and independent pathways; 3) Akt/mTOR/P70(S6K) axis activation; and, 4) fibrosis (TGF-ß, collagen1-A1/A3). Histopathology for inflammation, collagen, and fibroblast content, TUNEL staining, and metalloproteinase activity was performed. Apoptosis is only detected upon R in IM cardiomyocytes and progresses up to 6 days post-R mainly associated with infiltrated macrophages. The Akt/mTOR/P70(s6K) pathway is also activated upon R (IM) and remains elevated up to 6 days-R (P<0.05). Ischemia activates the TLR-4-MyD88-dependent (cytokines/chemokines) and -independent (IRF-3) pathways in IM and NIM and remains high up to 6 days post-R (P<0.05). Accordingly, leukocytes and macrophages are progressively recruited to the IM (P<0.05). Ischemia up-regulates pro-fibrotic TGF-ß that gradually rises collagen1-A1/-A3 mRNA with subsequent increase in total collagen fibrils and fibroblasts from 3 days-R onwards (P<0.005). MMP-2 activity increases from ischemia to 3 days post-R (P<0.05). We report that there is a timely coordinated cellular and molecular response to myocardial ischemia and R within the first 6 days after MI. In-depth understanding of the mechanisms involved in tissue repair is warranted to timely intervene and better define novel cardioprotective strategies.

Cholesterol-lowering strategies reduce vascular LRP1 overexpression induced by hypercholesterolaemia.

BACKGROUND: Low density lipoprotein receptor-related protein (LRP1) plays a key role on vascular functionality and is upregulated by hypercholesterolemia and hypertension. To investigate the effect of cholesterol-lowering interventions on vascular LRP1 over expression and whether simvastatin influences LRP1 expression. MATERIAL AND METHODS: Male New Zealand rabbits were recruited into various groups, one group was fed a normal chow diet for 28 days (control group, n = 6), other group (n = 24) was fed a hypercholesterolemic diet (HC), six rabbits were euthanized at day 28 to test the capacity of HC diet to induce early atherosclerosis and the rest at day 60 (n = 18) after receiving either HC diet (HC group, n = 6), HC diet with simvastatin (2·5 mg/kg.day) (HC+simv group, n = 6), or a normal chow diet (NC group, n = 6) for the last 32 days. RESULTS: High-cholesterol diet raised vascular LRP1 concomitantly with increased lipid, VSMC and macrophage content in the arterial intima. Simvastatin and return to normocholesterolemic diet significantly reduced systemic cholesterol levels and vascular lipid content. Interestingly, these interventions also downregulate LRP1 overexpression in the vascular wall although to a different extent (HC+simv: 75 ± 3·6%vs NC: 50 ± 3·5% versus, P = 0·002). Immunohistochemistry studies showed that LRP1 diminushion was associated to a reduction in the number of intimal VSMC in HC+simv.group. Simvastatin per se did not exert any significant effect on LRP1 expression in rabbit aortic smooth muscle cells (rSMC). CONCLUSIONS: Our results demonstrate that cholesterol-lowering interventions exerted down regulatory effects on vascular LRP1 over expression induced by hypercholesterolemia and that simvastatin did not influence LRP1 expression beyond its cholesterol-lowering effects.

Glucose-regulated protein 78 and platelet deposition: effect of rosuvastatin.

OBJECTIVE: To investigate the effect of rosuvastatin on platelet deposition under controlled shear rate conditions and to identify new platelet proteins involved in the interaction with the activating substrate. METHODS AND RESULTS: Platelet-vessel wall interaction and thrombosis take place under dynamic conditions involving the interaction of the exposed damaged vascular wall with the circulating blood cells and proteins. Blood was perfused over type I collagen at different wall shear rates, and platelet deposition was measured by confocal microscopy. Perfused effluent blood was collected, platelets were sequentially extracted based on differential protein solubility, and proteins were separated by 2D gel electrophoresis. Blockade of 3-hydroxy-3-methylglutaryl-coenzyme A reductase significantly reduced platelet deposition and modulated the expression pattern of 18 proteins in the platelet subproteome. Among them, an increase in platelet surface 78-kDa glucose-regulated protein (GRP78), a stress-inducible multifunctional endoplasmic reticulum protein, was clearly apparent. Immunoprecipitation of platelet GRP78 revealed its interaction with tissue factor. Moreover, blockade of surface GRP78 resulted in a substantial increase in platelet deposition and tissue factor procoagulant activity and in a decrease in clotting time. CONCLUSIONS: These findings demonstrate that blockade of 3-hydroxy-3-methylglutaryl-coenzyme A reductase reduces platelet deposition and inhibits GRP78 translocation from the platelet surface after shear and collagen activation. For the first time to our knowledge, this study reports on the presence and functional role of GRP78 in platelets and indicates that GRP78 has additional functions beyond those of a molecular chaperone.

Triglyceride-induced cardiac lipotoxicity is mitigated by Silybum marianum.

BACKGROUND AND AIMS: Silybum marianum (SM) is an herbal product with cytoprotective and antioxidant properties. We have previously demonstrated that SM ameliorates ventricular remodeling and improves cardiac performance. Here, we evaluated whether SM could exert beneficial effects against cardiac lipotoxicity in a pig model of closed-chest myocardial infarction (MI). METHODS: Study 1 investigated the effect of SM administration on lipid profile and any potential SM-related adverse effects. Animals received SM or placebo during 10 days and were afterward sacrificed. Study 2 evaluated the effectiveness of SM daily administration in reducing cardiac lipotoxicity in animals subjected to a 1.5h myocardial infarction (MI), who were subsequently reperfused for 2.5h and euthanized or kept under study for three weeks and then sacrificed. RESULTS: Animals administered a 10-day SM regime presented a sharp decline in plasma triglyceride levels vs. controls, with no other modifications in lipid profile. The decrease in triglyceride concentration was accompanied by a marked reduction in triglyceride intestinal absorption and glycoprotein-P expression. Three weeks post-MI the triglyceride content in the ischemic myocardium of the SM-treated animals was significantly lower than in the ischemic myocardium of placebo-controls. This effect was associated with an enhanced cardiac expression of PPARγ and triglyceride clearance receptors. This long-term SM-administration induced a lower expression of lipid receptors in subcutaneous adipose tissue. No SM-related side-effects were registered. CONCLUSION: SM administration reduces plasma triglyceride levels through attenuation of triglyceride intestinal absorption and modulates cardiac lipotoxicity in the ischemic myocardium, likely contributing to improve ventricular remodeling.

Rabbit as an animal model for the study of biological grafts in pelvic floor dysfunctions.

The aims of this study were to evaluate the feasibility of the New Zealand White (NZW) rabbit for studying implanted biomaterials in pelvic reconstructive surgery; and to compare the occurrence of graft-related complications of a commercial polypropylene (PP) mesh and new developed human dermal matrix implanted at vaginal and abdominal level. 20 white female NZW rabbits were randomized into two groups, experimental group (human acellular dermal matrices-hADM-graft) and control group (commercial PP graft). In each animal, grafts were surgically implanted subcutaneously in the abdominal wall and in the vaginal submucosa layer for 180 days. The graft segments were then removed and the surgical and clinical results were analyzed. The main surgical challenges during graft implantation were: (a) an adequate vaginal exposure while maintaining the integrity of the vaginal mucosa layer; (b) to keep aseptic conditions; (c) to locate and dissect the breast vein abdominal surgery; and (d) to withdraw blood samples from the ear artery. The most abnormal findings during the explant surgery were found in the PP group (33% of vaginal mesh extrusion) in comparison with the hADM group (0% of vaginal graft extrusion), p = 0.015. Interestingly, macroscopic observation showed that the integration of the vaginal grafts was more common in the hADM group (40%) than in the PP group, in which the vaginal mesh was identified in 100% of the animals (p = 0.014). The NZW rabbit is a good model for assessing materials to be used as grafts for pelvic reconstructive surgery and vaginal surgery. Animals are easily managed during the procedures, including surgical intervention and vaginal mucosa approach. Additionally, hADM is associated with fewer clinical complications, as well as better macroscopic tissue integration, compared to PP mesh.

Intravenous Statin Administration During Myocardial Infarction Compared With Oral Post-Infarct Administration.

BACKGROUND: Beyond lipid-lowering, statins exert cardioprotective effects. High-dose statin treatment seems to reduce cardiovascular complications in high-risk patients. The ideal timing and administration regime remain unknown. OBJECTIVES: This study compared the cardioprotective effects of intravenous statin administration during myocardial infarction (MI) with oral administration immediately post-MI. METHODS: Hypercholesterolemic pigs underwent MI induction (90 min of ischemia) and were kept for 42 days. Animals were distributed in 3 arms (A): A1 received an intravenous bolus of atorvastatin during MI; A2 received an intravenous bolus of vehicle during MI; and A3 received oral atorvastatin within 2 h post-MI. A1 and A3 remained on daily oral atorvastatin for the following 42 days. Cardiac magnetic resonance analysis (days 3 and 42 post-MI) and molecular/histological studies were performed. RESULTS: At day 3, A1 showed a 10% reduction in infarct size compared with A3 and A2 and a 50% increase in myocardial salvage. At day 42, both A1 and A3 showed a significant decrease in scar size versus A2; however, A1 showed a further 24% reduction versus A3. Functional analyses revealed improved systolic performance in A1 compared with A2 and less wall motion abnormalities in the jeopardized myocardium versus both groups at day 42. A1 showed enhanced collagen content and AMP-activated protein kinase activation in the scar, increased vessel density in the penumbra, higher tumor necrosis factor α plasma levels and lower peripheral blood mononuclear cell activation versus both groups. CONCLUSIONS: Intravenous administration of atorvastatin during MI limits cardiac damage, improves cardiac function, and mitigates remodeling to a larger extent than when administered orally shortly after reperfusion. This therapeutic approach deserves to be investigated in ST-segment elevation MI patients.