Single Intracoronary Injection of Encapsulated Antagomir-92a Promotes Angiogenesis and Prevents Adverse Infarct Remodeling

Small and large preclinical animal models have shown that antagomir-92a-based therapy reduces early postischemic loss of function, but its effect on postinfarction remodeling is not known. In addition, the reported remote miR-92a inhibition in noncardiac organs prevents the translation of nonvectorized miR-targeted therapy to the clinical setting. We investigated whether a single intracoronary administration of antagomir-92a encapsulated in microspheres could prevent deleterious remodeling of myocardium 1 month after acute myocardial infarction AUTHOR: Should "acute" be added before "myocardial infarction" (since abbreviation is AMI)? Also check at first mention in main text (AMI) without adverse effects. In a percutaneous pig model of reperfused AMI, a single intracoronary administration of antagomir-92a encapsulated in specific microspheres (9 μm poly-d,-lactide-co-glycolide [PLGA]) inhibited miR-92a in a local, selective, and sustained manner (n=3 pigs euthanized 1, 3, and 10 days after treatment; 8×, 2×, and 5×-fold inhibition at 1, 3, and 10 days). Downregulation of miR-92a resulted in significant vessel growth (n=27 adult minipigs randomly allocated to blind receive encapsulated antagomir-92a, encapsulated placebo, or saline [n=8, 9, 9]; P =0.001), reduced regional wall-motion dysfunction (P =0.03), and prevented adverse remodeling in the infarct area 1 month after injury (P =0.03). Intracoronary injection of microspheres had no significant adverse effect in downstream myocardium in healthy pigs (n=2), and fluorescein isothiocyanate albumin-PLGA microspheres were not found in myocardium outside the left anterior descending coronary artery territory (n=4) or in other organs (n=2). Early single intracoronary administration of encapsulated antagomir-92a in an adult pig model of reperfused AMI prevents left ventricular remodeling with no local or distant adverse effects, emerging as a promising therapeutic approach to translate to patients who suffer a large AMI

Spontaneous reperfusion enhances succinate concentration in peripheral blood from stemi patients but its levels does not correlate with myocardial infarct size or area at risk

Cardiovascular biology; Diagnostic markers; Prognostic markersBiología cardiovascular; Marcadores de diagnóstico; Marcadores pronósticosBiologia cardiovascular; Marcadors diagnòstics; Marcadors pronòsticsSuccinate is enhanced during initial reperfusion in blood from the coronary sinus in ST-segment elevation myocardial infarction (STEMI) patients and in pigs submitted to transient coronary occlusion. Succinate levels might have a prognostic value, as they may correlate with edema volume or myocardial infarct size. However, blood from the coronary sinus is not routinely obtained in the CathLab. As succinate might be also increased in peripheral blood, we aimed to investigate whether peripheral plasma concentrations of succinate and other metabolites obtained during coronary revascularization correlate with edema volume or infarct size in STEMI patients. Plasma samples were obtained from peripheral blood within the first 10 min of revascularization in 102 STEMI patients included in the COMBAT-MI trial (initial TIMI 1) and from 9 additional patients with restituted coronary blood flow (TIMI 2). Metabolite concentrations were analyzed by 1H-NMR. Succinate concentration averaged 0.069 ± 0.0073 mmol/L in patients with TIMI flow ≤ 1 and was significantly increased in those with TIMI 2 at admission (0.141 ± 0.058 mmol/L, p < 0.05). However, regression analysis did not detect any significant correlation between most metabolite concentrations and infarct size, extent of edema or other cardiac magnetic resonance (CMR) variables. In conclusion, spontaneous reperfusion in TIMI 2 patients associates with enhanced succinate levels in peripheral blood, suggesting that succinate release increases overtime following reperfusion. However, early plasma levels of succinate and other metabolites obtained from peripheral blood does not correlate with the degree of irreversible injury or area at risk in STEMI patients, and cannot be considered as predictors of CMR variables. Trial registration: Registered at www.clinicaltrials.gov (NCT02404376) on 31/03/2015. EudraCT number: 2015-001000-58.This work was supported by the Spanish Ministry of Economy and Competitiveness, Instituto de Salud Carlos III (Grants PI17/01397 and CIBERCV) and the Spanish Society of Cardiology (Proyectos de la FEC para Investigación Básica en Cardiología 2018, Sociedad Española de Cardiología), and was cofinanced by the European Regional Development Fund (ERDF-FEDER, a way to build Europe). Antonio Rodríguez-Sinovas has a consolidated Miguel Servet contract

Efecto de la infusión intracoronaria de antagomir-92a encapsulado en microesferas sobre la vasculogénesis y remodelado ventricular en un modelo porcino de infarto agudo de miocardio

Después de un infarto agudo de miocardio (IAM) puede aparecer un fenómeno denominado remodelado ventricular adverso consistente en un adelgazamiento y dilatación ventricular progresiva que aboca a la aparición de síntomas de insuficiencia cardíaca (IC). Aunque los tratamientos farmacológicos, la terapia de reperfusión coronaria y la resincronización han atenuado la progresión de este fenómeno, su prevención sigue siendo un reto para la cardiología. En la última década, la terapia celular proporcionó resultados prometedores en modelos animales de remodelado postIAM que no se han confirmado, en gran medida, al trasladarlos a la clínica, por lo que era necesaria la búsqueda de nuevas estrategias. Teniendo en cuenta que el tamaño del IAM es el principal predictor de remodelado y que el fenómeno de cicatrización requiere de oxígeno y nutrientes, intentar mejorar la red microvascular para salvar células y reparar el área dañada parece una terapia plausible. Sin embargo, los ensayos clínicos administrando factores proangiogénicos aislados para formar nuevos vasos no han obtenido los resultados esperados. La angiogénesis depende del equilibrio entre múltiples factores pro y antiangiogénicos, por lo que la administración de un solo factor puede verse contrarrestada por cambios en otros. La capacidad de los microRNAs para modular múltiples proteínas de vías funcionalmente relacionadas los ha convertido en una nueva diana terapéutica. Los microRNAs son pequeños oligonucleótidos que reprimen la síntesis de proteínas regulando procesos fisiológicos y fisiopatológicos. Algunos de ellos regulan la angiogénesis controlando la proliferación, diferenciación y migración de las células endoteliales. Además, el descubrimiento de que se puede modificar la expresión de dichos microRNAS, sobreexpresándolos o bien silenciándolos mediante antagomires, significó el nacimiento de una nueva terapéutica. Estudios experimentales han demostrado que podemos regular los genes vasculares in vitro e in vivo. Uno de dichos estudios reveló que el miR-92a juega un rol crítico en la neovascularización postnatal y en un modelo de ratón de IAM la administración de su antagomir-92a específico en inyecciones repetidas por vía intravenosa, indujo crecimiento de nuevos vasos en la cicatriz, mejorando la recuperación contráctil postinfarto. Sin embargo, el cluster 17-92a, donde se encuentra el miR-92a, es ubicuo y se ha relacionado con la aparición y progresión de algunos tumores, lo que genera preocupación sobre la seguridad de la vía intravenosa. La penetración no selectiva en células normales a distancia puede generar efectos adversos. Además, diferencias farmacocinéticas como el volumen de distribución entre los animales pequeños y el ser humano representan obstáculos en la translación de la terapia con antagomires a situaciones clínicas. El propósito de nuestro trabajo fue desarrollar un nuevo método para liberar antagomir-92a directamente en el tejido enfermo por vía intracoronaria, así como demostrar su efecto biológico sobre los cambios inherentes al remodelado ventricular. Ello nos pareció de gran interés porque sus conclusiones podrían condicionar la futura translación a pacientes, así como la posibilidad de extenderlo a otros antagomires y a otras afecciones patológicas. Desarrollamos microesferas (ME) biodegradables de ácido poliláctico-co-glicólico (PLGA) que quedan retenidas en los microvasos de la región infartada, evitando la biodistribución sistémica y siendo seguras localmente. Utilizamos un modelo porcino adulto, superando las limitaciones asociadas a diferencias de tamaño entre especies, y crónico, para observar los efectos sobre el remodelado, que acontece semanas después de un IAM. Esta es la primera vez que se demuestra que la administración intracoronaria de antagomir-92a encapsulado en ME genera vasos de forma significativa, lo que conduce a la prevención de la aparición de remodelado adverso al mes postIAM. Por tanto, aportamos las primeras evidencias de que la terapia intracoronaria con antagomir-92a encapsulado en ME es una terapéutica prometedora para aquellos pacientes que sufren un IAM grande y se encuentran en riesgo de desarrollar remodelado ventricular adverso.Myocardial infarction (AMI) may induce deleterious remodelling of myocardium involving thinning and expansion of the infarct area that results in ventricular dilatation, contractile dysfunction and subsequent heart failure. Pharmacological treatments and resynchronization therapy can attenuate adverse post-infarction remodelling but its prevention remains a daunting challenge for cardiac medicine. Cell therapies provided promising results in animal models of post-infarction remodelling but had a small if any effect in clinical trials and have not been so far translated to clinical practice. Novel treatment strategies preventing adverse left ventricular remodelling are therefore needed. Increasing blood supply to the infarcted tissue appears a logical approach to prevent ventricular remodelling. Reparative fibrosis and survival of viable myocardium requires supply of oxygenated blood and microvascular obstruction and microcirculation failure after AMI has been associated with the occurrence of adverse remodelling. Improving the vascular network by inducing neoangiogenesis in the healing area has been proposed to prevent it. MicroRNAs (miRs) are small, noncoding RNAs that are emerging as crucial regulators of vasculogenesis. Forced overexpression or inhibition of specific microRNAs in vitro enhances or blocks the growth of new blood vessels by regulating migration and proliferation of endothelial cells and allow the regulation of vascular genes in vivo. Experimental studies have revealed the anti-antiangiogenic activity of miR-92a and its critical role in postnatal neovascularization. In a mouse model of AMI, repetitive systemic administration of miR-92a-specific antagomir improved contractility and recovery of left ventricular function. However, the polycistronic microRNA 17-92a cluster is ubiquitously expressed and has been linked to tumourigenesis which raises concerns about the safety of intravenous administration of antagomirs of this cluster. In addition, pharmacokinetics issues such as biodistribution and nonselective cell penetration after systemic administration, represent potential obstacles in the translation to patients of therapies based on the administration of synthetic nucleic acids. The development of an efficient methods to deliver of miRs or antagomirs into targeted sites, enabling a reduction in dosage and high biosafety profile, would circumvent these limitations. Our goal was to test the efficacy and safety of a new strategy to prevent post-infarction myocardial remodelling based in the selective and sustained release of antagomir-92a into the infarct area. We found that a single intracoronary administration at the time of reperfusion of antagomir-92a encapsulated in specifically designed, bioabsorbable and biocompatible microspheres, inhibits miR-92a locally during one month after AMI, inducing vessel growth and preventing the development of adverse remodelling. These results identify local and sustained release of antagomir-92a as a new promising approach to the treatment of patients with myocardial infarction and may be other cardiovascular diseases

Efecto de la infusión intracoronaria de antagomir-92a encapsulado en microesferas sobre la vasculogénesis y remodelado ventricular en un modelo porcino de infarto agudo de miocardio

Después de un infarto agudo de miocardio (IAM) puede aparecer un fenómeno denominado remodelado ventricular adverso consistente en un adelgazamiento y dilatación ventricular progresiva que aboca a la aparición de síntomas de insuficiencia cardíaca (IC). Aunque los tratamientos farmacológicos, la terapia de reperfusión coronaria y la resincronización han atenuado la progresión de este fenómeno, su prevención sigue siendo un reto para la cardiología. En la última década, la terapia celular proporcionó resultados prometedores en modelos animales de remodelado postIAM que no se han confirmado, en gran medida, al trasladarlos a la clínica, por lo que era necesaria la búsqueda de nuevas estrategias. Teniendo en cuenta que el tamaño del IAM es el principal predictor de remodelado y que el fenómeno de cicatrización requiere de oxígeno y nutrientes, intentar mejorar la red microvascular para salvar células y reparar el área dañada parece una terapia plausible. Sin embargo, los ensayos clínicos administrando factores proangiogénicos aislados para formar nuevos vasos no han obtenido los resultados esperados. La angiogénesis depende del equilibrio entre múltiples factores pro y antiangiogénicos, por lo que la administración de un solo factor puede verse contrarrestada por cambios en otros. La capacidad de los microRNAs para modular múltiples proteínas de vías funcionalmente relacionadas los ha convertido en una nueva diana terapéutica. Los microRNAs son pequeños oligonucleótidos que reprimen la síntesis de proteínas regulando procesos fisiológicos y fisiopatológicos. Algunos de ellos regulan la angiogénesis controlando la proliferación, diferenciación y migración de las células endoteliales. Además, el descubrimiento de que se puede modificar la expresión de dichos microRNAS, sobreexpresándolos o bien silenciándolos mediante antagomires, significó el nacimiento de una nueva terapéutica. Estudios experimentales han demostrado que podemos regular los genes vasculares in vitro e in vivo. Uno de dichos estudios reveló que el miR-92a juega un rol crítico en la neovascularización postnatal y en un modelo de ratón de IAM la administración de su antagomir-92a específico en inyecciones repetidas por vía intravenosa, indujo crecimiento de nuevos vasos en la cicatriz, mejorando la recuperación contráctil postinfarto. Sin embargo, el cluster 17-92a, donde se encuentra el miR-92a, es ubicuo y se ha relacionado con la aparición y progresión de algunos tumores, lo que genera preocupación sobre la seguridad de la vía intravenosa. La penetración no selectiva en células normales a distancia puede generar efectos adversos. Además, diferencias farmacocinéticas como el volumen de distribución entre los animales pequeños y el ser humano representan obstáculos en la translación de la terapia con antagomires a situaciones clínicas. El propósito de nuestro trabajo fue desarrollar un nuevo método para liberar antagomir-92a directamente en el tejido enfermo por vía intracoronaria, así como demostrar su efecto biológico sobre los cambios inherentes al remodelado ventricular. Ello nos pareció de gran interés porque sus conclusiones podrían condicionar la futura translación a pacientes, así como la posibilidad de extenderlo a otros antagomires y a otras afecciones patológicas. Desarrollamos microesferas (ME) biodegradables de ácido poliláctico-co-glicólico (PLGA) que quedan retenidas en los microvasos de la región infartada, evitando la biodistribución sistémica y siendo seguras localmente. Utilizamos un modelo porcino adulto, superando las limitaciones asociadas a diferencias de tamaño entre especies, y crónico, para observar los efectos sobre el remodelado, que acontece semanas después de un IAM. Esta es la primera vez que se demuestra que la administración intracoronaria de antagomir-92a encapsulado en ME genera vasos de forma significativa, lo que conduce a la prevención de la aparición de remodelado adverso al mes postIAM. Por tanto, aportamos las primeras evidencias de que la terapia intracoronaria con antagomir-92a encapsulado en ME es una terapéutica prometedora para aquellos pacientes que sufren un IAM grande y se encuentran en riesgo de desarrollar remodelado ventricular adverso.Myocardial infarction (AMI) may induce deleterious remodelling of myocardium involving thinning and expansion of the infarct area that results in ventricular dilatation, contractile dysfunction and subsequent heart failure. Pharmacological treatments and resynchronization therapy can attenuate adverse post-infarction remodelling but its prevention remains a daunting challenge for cardiac medicine. Cell therapies provided promising results in animal models of post-infarction remodelling but had a small if any effect in clinical trials and have not been so far translated to clinical practice. Novel treatment strategies preventing adverse left ventricular remodelling are therefore needed. Increasing blood supply to the infarcted tissue appears a logical approach to prevent ventricular remodelling. Reparative fibrosis and survival of viable myocardium requires supply of oxygenated blood and microvascular obstruction and microcirculation failure after AMI has been associated with the occurrence of adverse remodelling. Improving the vascular network by inducing neoangiogenesis in the healing area has been proposed to prevent it. MicroRNAs (miRs) are small, noncoding RNAs that are emerging as crucial regulators of vasculogenesis. Forced overexpression or inhibition of specific microRNAs in vitro enhances or blocks the growth of new blood vessels by regulating migration and proliferation of endothelial cells and allow the regulation of vascular genes in vivo. Experimental studies have revealed the anti-antiangiogenic activity of miR-92a and its critical role in postnatal neovascularization. In a mouse model of AMI, repetitive systemic administration of miR-92a-specific antagomir improved contractility and recovery of left ventricular function. However, the polycistronic microRNA 17-92a cluster is ubiquitously expressed and has been linked to tumourigenesis which raises concerns about the safety of intravenous administration of antagomirs of this cluster. In addition, pharmacokinetics issues such as biodistribution and nonselective cell penetration after systemic administration, represent potential obstacles in the translation to patients of therapies based on the administration of synthetic nucleic acids. The development of an efficient methods to deliver of miRs or antagomirs into targeted sites, enabling a reduction in dosage and high biosafety profile, would circumvent these limitations. Our goal was to test the efficacy and safety of a new strategy to prevent post-infarction myocardial remodelling based in the selective and sustained release of antagomir-92a into the infarct area. We found that a single intracoronary administration at the time of reperfusion of antagomir-92a encapsulated in specifically designed, bioabsorbable and biocompatible microspheres, inhibits miR-92a locally during one month after AMI, inducing vessel growth and preventing the development of adverse remodelling. These results identify local and sustained release of antagomir-92a as a new promising approach to the treatment of patients with myocardial infarction and may be other cardiovascular diseases

Single Intracoronary Injection of Encapsulated Antagomir‐92a Promotes Angiogenesis and Prevents Adverse Infarct Remodeling

BACKGROUND: Small and large preclinical animal models have shown that antagomir‐92a‐based therapy reduces early postischemic loss of function, but its effect on postinfarction remodeling is not known. In addition, the reported remote miR‐92a inhibition in noncardiac organs prevents the translation of nonvectorized miR‐targeted therapy to the clinical setting. We investigated whether a single intracoronary administration of antagomir‐92a encapsulated in microspheres could prevent deleterious remodeling of myocardium 1 month after acute myocardial infarction AUTHOR: Should “acute” be added before “myocardial infarction” (since abbreviation is AMI)? Also check at first mention in main text (AMI) without adverse effects. METHODS AND RESULTS: In a percutaneous pig model of reperfused AMI, a single intracoronary administration of antagomir‐92a encapsulated in specific microspheres (9 μm poly‐d,‐lactide‐co‐glycolide [PLGA]) inhibited miR‐92a in a local, selective, and sustained manner (n=3 pigs euthanized 1, 3, and 10 days after treatment; 8×, 2×, and 5×‐fold inhibition at 1, 3, and 10 days). Downregulation of miR‐92a resulted in significant vessel growth (n=27 adult minipigs randomly allocated to blind receive encapsulated antagomir‐92a, encapsulated placebo, or saline [n=8, 9, 9]; P=0.001), reduced regional wall‐motion dysfunction (P=0.03), and prevented adverse remodeling in the infarct area 1 month after injury (P=0.03). Intracoronary injection of microspheres had no significant adverse effect in downstream myocardium in healthy pigs (n=2), and fluorescein isothiocyanate albumin‐PLGA microspheres were not found in myocardium outside the left anterior descending coronary artery territory (n=4) or in other organs (n=2). CONCLUSIONS: Early single intracoronary administration of encapsulated antagomir‐92a in an adult pig model of reperfused AMI prevents left ventricular remodeling with no local or distant adverse effects, emerging as a promising therapeutic approach to translate to patients who suffer a large AMI

Effect of COMBinAtion therapy with remote ischemic conditioning and exenatide on the Myocardial Infarct size: a two-by-two factorial randomized trial (COMBAT-MI).

Remote ischemic conditioning (RIC) and the GLP-1 analog exenatide activate different cardioprotective pathways and may have additive effects on infarct size (IS). Here, we aimed to assess the efficacy of RIC as compared with sham procedure, and of exenatide, as compared with placebo, and the interaction between both, to reduce IS in humans. We designed a two-by-two factorial, randomized controlled, blinded, multicenter, clinical trial. Patients with ST-segment elevation myocardial infarction receiving primary percutaneous coronary intervention (PPCI) within 6 h of symptoms were randomized to RIC or sham procedure and exenatide or matching placebo. The primary outcome was IS measured by late gadolinium enhancement in cardiac magnetic resonance performed 3-7 days after PPCI. The secondary outcomes were myocardial salvage index, transmurality index, left ventricular ejection fraction and relative microvascular obstruction volume. A total of 378 patients were randomly allocated, and after applying exclusion criteria, 222 patients were available for analysis. There were no significant interactions between the two randomization factors on the primary or secondary outcomes. IS was similar between groups for the RIC (24 ± 11.8% in the RIC group vs 23.7 ± 10.9% in the sham group, P = 0.827) and the exenatide hypotheses (25.1 ± 11.5% in the exenatide group vs 22.5 ± 10.9% in the placebo group, P = 0.092). There were no effects with either RIC or exenatide on the secondary outcomes. Unexpected adverse events or side effects of RIC and exenatide were not observed. In conclusion, neither RIC nor exenatide, or its combination, were able to reduce IS in STEMI patients when administered as an adjunct to PPCI.The trial was sponsored with a Grant from Instituto de Salud Carlos III (PIE 13/00027) and a Grant from Generalitat de Catalunya (PERIS SLT/2381/2016). The sponsors have not been involved in the design, conduct, collection, analysis, interpretation of the data, nor in the preparation, review or approval of the manuscriptS