Molecular and metabolic orchestration of the lymphatic vasculature in physiology and pathology.

Lymphangiogenesis refers to the generation of new lymphatic vessels from pre-existing ones. During development and particular adult states, lymphatic endothelial cells (LEC) undergo reprogramming of their transcriptomic and signaling networks to support the high demands imposed by cell proliferation and migration. Although there has been substantial progress in identifying growth factors and signaling pathways controlling lymphangiogenesis in the last decades, insights into the role of metabolism in lymphatic cell functions are just emerging. Despite numerous similarities between the main metabolic pathways existing in LECs, blood ECs (BEC) and other cell types, accumulating evidence has revealed that LECs acquire a unique metabolic signature during lymphangiogenesis, and their metabolic engine is intertwined with molecular regulatory networks, resulting in a tightly regulated and interconnected process. Considering the implication of lymphatic dysfunction in cancer and lymphedema, alongside other pathologies, recent findings hold promising opportunities to develop novel therapeutic approaches. In this review, we provide an overview of the status of knowledge in the molecular and metabolic network regulating the lymphatic vasculature in health and disease.

Author Correction: The Intrapericardial Delivery of Extracellular Vesicles from Cardiosphere-Derived Cells Stimulates M2 Polarization during the Acute Phase of Porcine Myocardial Infarction.

The original version of this article unfortunately contained a mistake. In the author group, the correct family name of Dr. Rebeca is "Blázquez" and the correct family name of Dr. Francisco Miguel is "Sánchez-Margallo."

The Intrapericardial Delivery of Extracellular Vesicles from Cardiosphere-Derived Cells Stimulates M2 Polarization during the Acute Phase of Porcine Myocardial Infarction.

Acute myocardial infarction triggers a strong inflammatory response in the affected cardiac tissue. New therapeutic tools based on stem cell therapy may modulate the unbalanced inflammation in the damaged cardiac tissue, contributing to the resolution of this pathological condition. The main goal of this study was to analyze the immunomodulatory effects of cardiosphere-derived cells (CDCs) and their extracellular vesicles (EV-CDCs), delivered by intrapericardial administration in a clinically relevant animal model, during the initial pro-inflammatory phase of an induced myocardial infarction. This effect was assessed in peripheral blood and pericardial fluid leukocytes from infarcted animals. Additionally, cardiac functional parameters, troponin I, hematological and biochemical components were also analyzed to characterize myocardial infarction-induced changes, as well as the safety aspects of these procedures. Our preclinical study demonstrated a successful myocardial infarction induction in all animals, without any reported adverse effect related to the intrapericardial administration of CDCs or EV-CDCs. Significant changes were observed in biochemical and immunological parameters after myocardial infarction. The analysis of peripheral blood leukocytes revealed an increase of M2 monocytes in the EV-CDCs group, while no differences were reported in other lymphocyte subsets. Moreover, arginase-1 (M2-differentiation marker) was significantly increased in pericardial fluids 24 h after EV-CDCs administration. In summary, we demonstrate that, in our experimental conditions, intrapericardially administered EV-CDCs have an immunomodulatory effect on monocyte polarization, showing a beneficial effect for counteracting an unbalanced inflammatory reaction in the acute phase of myocardial infarction. These M2 monocytes have been defined as "pro-regenerative cells" with a pro-angiogenic and anti-inflammatory activity.

Dose-dependent improvement of cardiac function in a swine model of acute myocardial infarction after intracoronary administration of allogeneic heart-derived cells.

BACKGROUND: Allogeneic cardiac-derived progenitor cells (CPC) without immunosuppression could provide an effective ancillary therapy to improve cardiac function in reperfused myocardial infarction. We set out to perform a comprehensive preclinical feasibility and safety evaluation of porcine CPC (pCPC) in the infarcted porcine model, analyzing biodistribution and mid-term efficacy, as well as safety in healthy non-infarcted swine. METHODS: The expression profile of several pCPC isolates was compared with humans using both FACS and RT-qPCR. ELISA was used to compare the functional secretome. One week after infarction, female swine received an intracoronary (IC) infusion of vehicle (CON), 25 × 106 pCPC (25 M), or 50 × 106 pCPC (50 M). Animals were followed up for 10 weeks using serial cardiac magnetic resonance imaging to assess functional and structural remodeling (left ventricular ejection fraction (LVEF), systolic and diastolic volumes, and myocardial salvage index). Statistical comparisons were performed using Kruskal-Wallis and Mann-Whitney U tests. Biodistribution analysis of 18F-FDG-labeled pCPC was also performed 4 h after infarction in a different subset of animals. RESULTS: Phenotypic and functional characterization of pCPC revealed a gene expression profile comparable to their human counterparts as well as preliminary functional equivalence. Left ventricular functional and structural remodeling showed significantly increased LVEF 10 weeks after IC administration of 50 M pCPC, associated to the recovery of left ventricular volumes that returned to pre-infarction values (LVEF at 10 weeks was 42.1 ± 10.0% in CON, 46.5 ± 7.4% in 25 M, and 50.2 ± 4.9% in 50 M, p < 0.05). Infarct remodeling was also improved following pCPC infusion with a significantly higher myocardial salvage index in both treated groups (0.35 ± 0.20 in CON; 0.61 ± 0.20, p = 0.04, in 25 M; and 0.63 ± 0.17, p = 0.01, in 50 M). Biodistribution studies demonstrated cardiac tropism 4 h after IC administration, with substantial myocardial retention of pCPC-associated tracer activity (18% of labeled cells in the heart), and no obstruction of coronary flow, indicating their suitability as a cell therapy product. CONCLUSIONS: IC administration of allogeneic pCPC at 1 week after acute myocardial infarction is feasible, safe, and associated with marked structural and functional benefit. The robust cardiac tropism of pCPC and the paracrine effects on left ventricle post-infarction remodeling established the preclinical bases for the CAREMI clinical trial (NCT02439398).

Identification of very early inflammatory markers in a porcine myocardial infarction model.

BACKGROUND: Acute myocardial infarction (AMI) is one of the most deleterious conditions leading to cardiovascular diseases and mortality. The importance of an early and accurate diagnosis assures immediate medical treatments, which are fundamental to reduce mortality and improve prognoses. AMI is associated to an inflammatory response which includes the increase of circulating inflammatory cytokines, chemokines and immune cell activation. This study aimed to identify which are the very early immune-related biomarkers that may be used as predictors of myocardial infarction severity. In order to mimic the pathophysiological events involved in human myocardial infarction, a temporary occlusion (90 min) of the mid-left anterior descending coronary artery was performed in a swine animal model. RESULTS: Lymphocyte subsets analysis in peripheral blood revealed significant alterations in CD4+/CD8+ ratio and naïve and effector/memory T cell percentages at 1 h post-myocardial infarction. Changes in TH1/TH2-related cytokine, monocyte and neutrophil markers gene expression were observed in peripheral blood lymphocytes, as well. Additionally, significant correlations between cardiac parameters (cardiac enzymes, left ventricular ejection fraction and % infarct) and blood-derived parameters (cytokine expression and lymphocyte subset distribution) were found. CONCLUSIONS: Peripheral blood lymphocyte alterations are easily and swiftly detectable, so they may be good biomarkers for a very early prognosis and to predict myocardial infarction severity.

Intrapericardial Delivery of Cardiosphere-Derived Cells: An Immunological Study in a Clinically Relevant Large Animal Model.

INTRODUCTION: The intrapericardial delivery has been defined as an efficient method for pharmacological agent delivery. Here we hypothesize that intrapericardial administration of cardiosphere-derived cells (CDCs) may have an immunomodulatory effect providing an optimal microenvironment for promoting cardiac repair. To our knowledge, this is the first report studying the effects of CDCs for myocardial repair using the intrapericardial delivery route. MATERIAL AND METHODS: CDCs lines were isolated, expanded and characterized by flow cytometry and PCR. Their differentiation ability was determined using specific culture media and differential staining. 300,000 CDCs/kg were injected into the pericardial space of a swine myocardial infarcted model. Magnetic resonance imaging, biochemical analysis of pericardial fluid and plasma, cytokine measurements and flow cytometry analysis were performed. RESULTS: Our results showed that, phenotype and differentiation behavior of porcine CDCs were equivalent to previously described CDCs. Moreover, the intrapericardial administration of CDCs fulfilled the safety aspects as non-adverse effects were reported. Finally, the phenotypes of resident lymphocytes and TH1 cytokines in the pericardial fluid were significantly altered after CDCs administration. CONCLUSIONS: The pericardial fluid could be considered as a safe and optimal vehicle for CDCs administration. The observed changes in the studied immunological parameters could exert a modulation in the inflammatory environment of infarcted hearts, indirectly benefiting the endogenous cardiac repair.

Intrapericardial administration of mesenchymal stem cells in a large animal model: a bio-distribution analysis.

The appropriate administration route for cardiovascular cell therapy is essential to ensure the viability, proliferative potential, homing capacity and implantation of transferred cells. At the present, the intrapericardial administration of pharmacological agents is considered an efficient method for the treatment of cardiovascular diseases. However, only a few reports have addressed the question whether the intrapericardial delivery of Mesenchymal Stem Cells (MSCs) could be an optimal administration route. This work firstly aimed to analyze the pericardial fluid as a cell-delivery vehicle. Moreover, the in vivo biodistribution pattern of intrapericardially administered MSCs was evaluated in a clinically relevant large animal model. Our in vitro results firstly showed that, MSCs viability, proliferative behavior and phenotypic profile were unaffected by exposure to pericardial fluid. Secondly, in vivo cell tracking by magnetic resonance imaging, histological examination and Y-chromosome amplification clearly demonstrated the presence of MSCs in pericardium, ventricles (left and right) and atrium (left and right) when MSCs were administered into the pericardial space. In conclusion, here we demonstrate that pericardial fluid is a suitable vehicle for MSCs and intrapericardial route provides an optimal retention and implantation of MSCs.

Noninvasive identification of epicardial ventricular tachycardia substrate by magnetic resonance-based signal intensity mapping.

BACKGROUND: Endo-epicardial substrate ablation reduces ventricular tachycardia (VT) recurrences; however, not all patients in whom the epicardium is explored have a VT substrate. Contrast-enhanced magnetic resonance imaging (ceMRI) is used to characterize VT substrate after myocardial infarction. OBJECTIVE: The purpose of this study was to determine if epicardial VT substrate can be identified noninvasively by ceMRI-based endo-epicardial signal intensity (SI) mapping. METHODS: Myocardial infarction was induced in 31 pigs. Four or 16 weeks later, ceMRI was obtained, and the averaged subendocardial and subepicardial SIs were projected onto 3-dimensional endocardial and epicardial shells in which dense scar, heterogeneous tissue (HT), and normal tissue were differentiated. An HT channel was defined as a corridor of HT surrounded by dense scar and connected to normal tissue. A "patchy" scar pattern was defined as the presence of at least 3 dense scar islets surrounded by HT forming ≥2 HT channels. Electrophysiologic study was performed after ceMRI. RESULTS: Thirty-three different sustained monomorphic VTs (291 ± 49 ms) were induced in 25 pigs. Mid-diastolic electrograms were recorded in the endocardium (endocardial VT) in 17 and in the epicardium (epicardial VT) in 13. Epicardial SI mapping showed that scar area was similar in animals with and without epicardial VT (24 ± 6 cm2 vs. 25 ± 12 cm2), but HT covered a higher surface of the epicardial scar in animals with VT (76 ± 6% vs. 61 ± 10%, P = .03). A patchy scar pattern was observed in all animals with epicardial VT but only in 3 animals without VT (P < .001). CONCLUSION: CeMRI-based SI mapping allows identification of the epicardial VT substrate.

Modelos animales en el aprendizaje de cardiología intervencionista / Animal models used for training in interventional cardiology

El uso de animales para la experimentación y el aprendizaje de las distintas técnicas quirúrgicas están bien establecidos y regulados desde hace muchos años. La progresión técnica de los simuladores complementa el empleo de modelos animales para el perfeccionamiento de las habilidades necesarias. El uso de modelo vivo para la demostración de ciertas técnicas, equipos o aprendizaje en el campo quirúrgico está aún vigente, teniendo en cuenta las diferentes guías y los requisitos aplicables en cada país. Sin embargo, en el terreno de la cardiología intervencionista, el empleo de modelos animales para la formación es casi anecdótico. Se revisan en este artículo las potenciales aplicaciones de los modelos animales en distintos campos del intervencionismo cardiaco, tanto coronario como estructural, así como las particularidades de cada especie animal en este sentido. Se discuten los aspectos éticos y legales, y se finaliza con una propuesta de integración de este tipo de aprendizaje en el programa de formación de la especialidad (AU)

The use of animal models for experimentation and training in surgical techniques is well-established and has been regulated for many years. Technical advances mean that simulators now complement the use of animal models for acquiring surgical skills. Nevertheless, live animal models are still used for demonstrating the application of particular techniques and devices and for surgical training, necessarily in accordance with the relevant guidelines and regulations of the country concerned. However, the use of animal models for training in interventional cardiology is minimal. This article provides a review of the potential applications of animal models in different areas of interventional cardiology, whether for coronary disease or structural heart disease, and summarizes the distinctive characteristics of each species used. Ethical and legal issues are also discussed. Finally, it is proposed that this kind of training should be integrated into educational programs in the specialty (AU)

Se relaciona la severidad del asma con el trastorno de ansiedad generalizada y el trastorno depresivo mayor?: estudio de casos y controles / Is asthma severity related to generalized anxiety disorder and mayor depressive disorder?: a case-control study

Introducción: Alrededor del mundo, más de cien millones de personas presentan asma. En esta población se presenta una elevada prevalencia del episodio depresivo mayor (EDM) y trastorno de ansiedad generalizada (TAG); sin embargo, esta asociación no se ha estudiado en pacientes colombianos. Objetivo: Establecer si la severidad del asma se asocia a la presencia de trastorno depresivo mayor (TDM) y el TAG en adultos de la consulta externa de neumología de Bucaramanga, Colombia. Método: Se diseñó un estudio de casos (44 pacientes con asma severa) y controles (88 con asma leve) pareados por edad, sexo y nivel socioeconómico. Los diagnósticos de TDM y TAG actual se realizaron con la entrevista clínica estructurada para los trastornos del eje I (SCID-I) según el DSM-IV-TR. Resultados: Las prevalencias actuales de TDM fueron 27,2% y 29,5% en los pacientes con asma leve y en aquellos con asma severa, respectivamente (OR=1,12; IC95% 0,46-2,69). Las prevalencias actuales para TAG fueron 43,1% y 45,4% en los pacientes con asma leve y en aquellos con asma severa, respectivamente (OR=1,10; IC95% 0,49-2,44). Conclusión: No existe asociación entre TDM y TAG y el grado de severidad del asma en pacientes de Bucaramanga, Colombia...

Introduction: World-wide more than one hundred million people suffer from asthma. This population presents a high prevalence of major depressive disorder (MDD) and generalized anxiety disorder (GAD). However, this association has not been investigated IN Colombian asthma outpatients. Objective: To establish whether asthma severity is associated with MDD or GAD in adult asthma outpatients in Bucaramanga, Colombia. Method: A study on cases (44 patients with severe asthma) and controls (88 patients with mild asthma), matched according to age, sex and socioeconomic status, was designed. The current MDD and GAD diagnoses were made using the Structured Clinical Interview for DSM-IV Axis I Disorders-Clinical version (SCID-CV). Results: The current prevalence of MDD WAS 27.2% and 29.5% in patients with mild asthma and patients with severe asthma, respectively (OR=1.12, 95% CI 0.46-2.69). The prevalence of GAD was 43.1% and 45.4% in patients with mild asthma and patients with severe asthma, respectively (OR=1.10, 95% CI 0.49-2.44). Conclusion: There is no association between MMD and GAD and the degree of severity in asthma patients in Bucaramanga, Colombia...