Effects of Trimetazidine on Right Ventricular Function and Ventricular Remodeling in Patients with Pulmonary Artery Hypertension: A Randomised Controlled Trial.

BACKGROUND: Pulmonary artery hypertension (PAH) is a chronic and progressive disease. Although current therapy has improved the disease prognosis, PAH has a poor survival rate. The key feature leading to disease progression and death is right ventricular (RV) failure. METHODS AND RESULTS: We assessed the role of trimetazidine, a fatty acid beta-oxidation (FAO) inhibitor, in right ventricular function, remodeling, and functional class in PAH patients, with a placebo-controlled double-blind, case-crossover trial. Twenty-seven PAH subjects were enrolled, randomized, and assigned to trimetazidine or placebo for three months and then reallocated to the other study arm. The primary endpoint was RV morphology and function change after three months of treatment. Secondary endpoints were the change in exercise capacity assessed by a 6 min walk test after three months of treatment and the change in pro-BNP and Galectin-3 plasma levels after three months. Trimetazidine use was safe and well-tolerated. After three months of treatment, patients in the trimetazidine group showed a small but significant reduction of RV diastolic area, and a substantial increase in the 6 min walk distance (418 vs. 438 mt, p = 0.023), without significant changes in biomarkers. CONCLUSIONS: A short course of trimetazidine is safe and well-tolerated on PAH patients, and it is associated with significant increases in the 6MWT and minor but significant improvement in RV remodeling. The therapeutic potential of this drug should be evaluated in larger clinical trials.

Inner mitochondrial membrane structure and fusion dynamics are altered in senescent human iPSC-derived and primary rat cardiomyocytes.

Dysfunction of the aging heart is a major cause of death in the human population. Amongst other tasks, mitochondria are pivotal to supply the working heart with ATP. The mitochondrial inner membrane (IMM) ultrastructure is tailored to meet these demands and to provide nano-compartments for specific tasks. Thus, function and morphology are closely coupled. Senescent cardiomyocytes from the mouse heart display alterations of the inner mitochondrial membrane. To study the relation between inner mitochondrial membrane architecture, dynamics and function is hardly possible in living organisms. Here, we present two cardiomyocyte senescence cell models that allow in cellular studies of mitochondrial performance. We show that doxorubicin treatment transforms human iPSC-derived cardiomyocytes and rat neonatal cardiomyocytes in an aged phenotype. The treated cardiomyocytes display double-strand breaks in the nDNA, have ß-galactosidase activity, possess enlarged nuclei, and show p21 upregulation. Most importantly, they also display a compromised inner mitochondrial structure. This prompted us to test whether the dynamics of the inner membrane was also altered. We found that the exchange of IMM components after organelle fusion was faster in doxorubicin-treated cells than in control cells, with no change in mitochondrial fusion dynamics at the meso-scale. Such altered IMM morphology and dynamics may have important implications for local OXPHOS protein organization, exchange of damaged components, and eventually the mitochondrial bioenergetics function of the aged cardiomyocyte.

Mitochondrial function, dynamics and quality control in the pathophysiology of HFpEF.

Heart failure (HF) is one of the leading causes of hospitalization for the adult population and a major cause of mortality worldwide. The HF syndrome is characterized by the heart's inability to supply the cardiac output required to meet the body's metabolic requirements or only at the expense of elevated filling pressures. HF without overt impairment of left ventricular ejection fraction (LVEF) was initially labeled as "diastolic HF" until recognizing the coexistence of both systolic and diastolic abnormalities in most cases. Acknowledging these findings, the preferred nomenclature is HF with preserved EF (HFpEF). This syndrome primarily affects the elderly population and is associated with a heterogeneous overlapping of comorbidities that makes its diagnosis challenging. Despite extensive research, there is still no evidence-based therapy for HFpEF, reinforcing the need for a thorough understanding of the pathophysiology underlying its onset and progression. The role of mitochondrial dysfunction in developing the pathophysiological changes that accompany HFpEF onset and progression (low-grade systemic inflammation, oxidative stress, endothelial dysfunction, and myocardial remodeling) has just begun to be acknowledged. This review summarizes our current understanding of the participation of the mitochondrial network in the pathogenesis of HFpEF, with particular emphasis on the signaling pathways involved, which may provide future therapeutic targets.

Novel molecular insights and public omics data in pulmonary hypertension.

Pulmonary hypertension is a rare disease with high morbidity and mortality which mainly affects women of reproductive age. Despite recent advances in understanding the pathogenesis of pulmonary hypertension, the high heterogeneity in the presentation of the disease among different patients makes it difficult to make an accurate diagnosis and to apply this knowledge to effective treatments. Therefore, new studies are required to focus on translational and personalized medicine to overcome the lack of specificity and efficacy of current management. Here, we review the majority of public databases storing 'omics' data of pulmonary hypertension studies, from animal models to human patients. Moreover, we review some of the new molecular mechanisms involved in the pathogenesis of pulmonary hypertension, including non-coding RNAs and the application of 'omics' data to understand this pathology, hoping that these new approaches will provide insights to guide the way to personalized diagnosis and treatment.

Moderate Exercise in Spontaneously Hypertensive Rats Is Unable to Activate the Expression of Genes Linked to Mitochondrial Dynamics and Biogenesis in Cardiomyocytes.

Hypertension (HTN) is a public health concern and a major preventable cause of cardiovascular disease (CVD). When uncontrolled, HTN may lead to adverse cardiac remodeling, left ventricular hypertrophy, and ultimately, heart failure. Regular aerobic exercise training exhibits blood pressure protective effects, improves myocardial function, and may reverse pathologic cardiac hypertrophy. These beneficial effects depend at least partially on improved mitochondrial function, decreased oxidative stress, endothelial dysfunction, and apoptotic cell death, which supports the general recommendation of moderate exercise in CVD patients. However, most of these mechanisms have been described on healthy individuals; the effect of moderate exercise on HTN subjects at a cellular level remain largely unknown. We hypothesized that hypertension in adult spontaneously hypertensive rats (SHRs) reduces the mitochondrial response to moderate exercise in the myocardium. Methods: Eight-month-old SHRs and their normotensive control-Wistar-Kyoto rats (WKYR)-were randomly assigned to moderate exercise on a treadmill five times per week with a running speed set at 10 m/min and 15° inclination. The duration of each session was 45 min with a relative intensity of 70-85% of the maximum O2 consumption for a total of 8 weeks. A control group of untrained animals was maintained in their cages with short sessions of 10 min at 10 m/min two times per week to maintain them accustomed to the treadmill. After completing the exercise protocol, we assessed maximum exercise capacity and echocardiographic parameters. Animals were euthanized, and heart and muscle tissue were harvested for protein determinations and gene expression analysis. Measurements were compared using a nonparametric ANOVA (Kruskal-Wallis), with post-hoc Dunn's test. Results: At baseline, SHR presented myocardial remodeling evidenced by left ventricular hypertrophy (interventricular septum 2.08 ± 0.07 vs. 1.62 ± 0.08 mm, p < 0.001), enlarged left atria (0.62 ± 0.1 mm vs. 0.52 ± 0.1, p = 0.04), and impaired diastolic function (E/A ratio 2.43 ± 0.1 vs. 1.56 ± 0.2) when compared to WKYR. Moderate exercise did not induce changes in ventricular remodeling but improved diastolic filling pattern (E/A ratio 2.43 ± 0.1 in untrained SHR vs. 1.89 ± 0.16 trained SHR, p < 0.01). Histological analysis revealed increased myocyte transversal section area, increased Myh7 (myosin heavy chain 7) expression, and collagen fiber accumulation in SHR-control hearts. While the exercise protocol did not modify cardiac size, there was a significant reduction of cardiomyocyte size in the SHR-exercise group. Conversely, titin expression increased only WYK-exercise animals but remained unchanged in the SHR-exercise group. Mitochondrial response to exercise also diverged between SHR and WYKR: while moderate exercise showed an apparent increase in mRNA levels of Ppargc1α, Opa1, Mfn2, Mff, and Drp1 in WYKR, mitochondrial dynamics proteins remained unchanged in response to exercise in SHR. This finding was further confirmed by decreased levels of MFN2 and OPA1 in SHR at baseline and increased OPA1 processing in response to exercise in heart. In summary, aerobic exercise improves diastolic parameters in SHR but fails to activate the cardiomyocyte mitochondrial adaptive response observed in healthy individuals. This finding may explain the discrepancies on the effect of exercise in clinical settings and evidence of the need to further refine our understanding of the molecular response to physical activity in HTN subjects.

Experiencia inicial con el uso de trombolisis local asistida por catéter de ultrasonido terapeútico (EKOSonic®) en pacientes con tromboembolismo pulmonar agudo / Use of local thrombolysis associated to therapeutic ultrasound (EKOSonic) in patients with acute pulmonary thromboembolism: a preliminary experience

INTRODUCCIÓN: El tromboembolismo pulmonar (TEP) es una causa frecuente de morbimortalidad cardiovascular y la trombolisis local asistida por ultrasonido (TLUS) constituye una alternativa de tratamiento validada para pacientes de riesgo intermedio. No existen reportes del uso de esta tecnología en el ámbito nacional. MÉTODOS: Análisis descriptivo, prospectivo, sobre una serie de pacientes con TEP agudo, de riesgo intermedio, tratados en forma percutánea con trombolisis local asistida por catéter de ultrasonido terapéutico (EKOSonic®). Se analiza la eficacia y seguridad del procedimiento mediante variables clínicas, hemodinámicas y radiológicas, así como desenlaces intra hospitalarios. Se reporta, además, el seguimiento a 30 días. RESULTADOS: Entre Junio de 2019 y Marzo de 2020, 4 pacientes con TEP de riesgo intermedio fueron tratados con esta técnica. El score PESI (Pulmonary Embolism severity Index) promedio era de 79,5 + 6,1. Dos pacientes requirieron la instalación de 2 catéteres para efectuar terapia bilateral. Se observó una reducción promedio en la presión sistólica de arteria pulmonar de 29% y en 3 de los 4 enfermos se logró revertir la dilatación ventricular derecha presente al ingreso. La carga trombótica se redujo en un 20% medido por score CTOI. No hubo complicaciones intraoperatorias ni intrahospitalarias asociadas a la intervención. CONCLUSIONES: En esta serie inicial, el uso de la trombolisis local con catéter de ultrasonido en pacientes con TEP de riesgo intermedio fue segura y efectiva. Los resultados perioperatorios y a 30 días fueron comparables a los descritos en experiencias internacionales; sin embargo, aún se requieren de estudios con mayor número de pacientes para confirmar los beneficios de esta técnica en nuestro medio.

BACKGROUND: Pulmonary thromboembolism (PE) is a common cause of cardiovascular morbidity and mortality and local ultrasound-assisted thrombolysis (USAT) is a validated alternative treatment for intermediate-risk patients. There are no reports on the use of this technology in our country. METHODS: Prospective series of patients with acute, intermediate-risk PE treated percutaneously with therapeutic ultrasound catheter-assisted local thrombolysis (EKOSonic®). The efficacy and safety of the procedure were analyzed using clinical, hemodynamic, and radiological variables, as well as intra-hospital outcomes. The 30-day follow-up is also reported. RESULTS: between June 2019 and March 2020, a total of 4 patients with intermediate-risk PE were treated with this technique. The average PESI score was 79.5 + 6.1. Two out of 4 patients required the use of 2 catheters for bilateral therapy. The average reduction in systolic pressure of the pulmonary artery was 29% and 3 patients reversed the right ventricular dilation present at admission. The thrombotic burden was reduced by 20% according to the Computed Tomography Obstruction Index (CTOI). There were no intraoperative or in hospital complications associated with the intervention. CONCLUSION: In this initial series, the use of local thrombolysis with an ultrasound catheter in patients with intermediate-risk PE was safe and effective. The perioperative and 30-day outcomes were similar to those previously reported in international series. However, larger randomized trials are needed to confirm this potential benefit.

Emerging role of mitophagy in cardiovascular physiology and pathology.

Healthy mitochondrial function is imperative for most tissues, but especially those with a high energy demand. Robust evidence linking mitochondrial dysfunction with cardiovascular disease has demonstrated that mitochondrial activity is highly relevant to cardiac muscle performance. Mitochondrial homeostasis is maintained through coordination among the processes that comprise the so-called mitochondrial dynamics machinery. The most-studied elements of cardiac mitochondrial dynamics are mitochondrial fission and fusion, biogenesis and degradation. Selective autophagic removal of mitochondria (mitophagy) is essential for clearing away defective mitochondria but can lead to cell damage and death if not tightly controlled. In cardiovascular cells such as cardiomyocytes and cardiac fibroblasts, mitophagy is involved in metabolic activity, cell differentiation, apoptosis and other physiological processes related to major phenotypic changes. Modulation of mitophagy has detrimental and/or beneficial outcomes in various cardiovascular diseases, suggesting that a deeper understanding of the mechanisms underlying mitochondrial degradation in the heart could provide valuable clinical insights. Here, we discuss current evidence supporting the role of mitophagy in cardiac pathophysiology, with an emphasis on different research models and their interpretations; basic concepts related to this selective autophagy; and the most commonly used experimental approaches for studying this mechanism. Finally, we provide a comprehensive literature analysis on the role of mitophagy in heart failure, ischemia/reperfusion, diabetic cardiomyopathy and other cardiovascular diseases, as well as its potential biomedical applications.

Early left atrial dysfunction is associated with suboptimal cardiovascular health.

AIMS: Two-dimensional speckle-tracking echocardiography can assess left atrial (LA) function by measuring atrial volumes and deformation parameters (strain, strain rate). This cross-sectional analysis explores the association between ideal CV health (CVH), LA function, and systemic biomarkers in healthy individuals from the Chilean MAUCO Cohort. METHODS: We enrolled 95 MAUCO participants with different levels of CVH (mean age: 51 ± 8 years). We categorized participants into low or high CVH groups: A: 0-2, or B: 3-6 CVH risk factors. 2D echocardiography, glucose, insulin, total cholesterol, triglycerides, proBNP, hsCRP, insulin resistance index (HOMA), and right and left atrial strain (RASs and LASs, respectively) were determined. RESULTS: LASs was lower in Group A, while systolic and diastolic blood pressure (BP), body mass index (BMI), insulin, HOMA, total cholesterol, triglycerides, and LV and RV end-diastolic volume were significantly higher in Group A than Group B (P < .01). Change in LASs was inversely correlated with insulin (P = .040), HOMA (P = .013), total cholesterol (P = .039), glycemia (P = .018), and BMI (P = .0.037). CONCLUSION: LASs during the reservoir phase was diminished in subjects with a lower level of CVH. Higher insulin, HOMA, total cholesterol, glycemia, and BMI values were associated with decreased LA deformation during the reservoir phase. Morphofunctional alterations of the LA were also identified in the group with suboptimal CVH, as well as BP values in the range of hypertension. LA dysfunction in an asymptomatic population, along with metabolic syndrome, could be an early event in the continuum of CV damage.

Menores niveles circulantes del péptido vasoactivo y cardioprotector angiotensina-(1-9) en pacientes con hipertension arterial pulmonar / Lower circulating levels of angiotensin-(1-9), a vasoactive and cardio-protective peptide in patients with pulmonary artery hypertension

RESUMEN: Introducción: La vía clásica del sistema renina-angiotensina (SRA) está activado en pacientes con hipertensión arterial pulmonar (HAP). Previamente, hemos encontrado que en la disfunción ventricular post infarto al miocardio experimental la activación del eje clásico del SRA, dado por la enzima convertidora de angiotensina I (ECA) y angiotensina (Ang ) II se correlaciona negativamente con el eje paralelo del SRA dado por la ECA homóloga (ECA2) y el péptido vasoactivo y cardioprotector Ang-(1-9). Resultados preclínicos muestran la eficacia de la administración de Ang-(1-9) en el tratamiento del remodelamiento cardiovascular patológico. Hasta la fecha no existen antecedentes de los niveles circulantes de Ang-(1-9) en pacientes con hipertensión arterial pulmonar comparados con sujetos sanos. Objetivo: Determinar los niveles circulantes del péptido vasoactivo y cardiprotector Ang-(1-9) en pacientes con HAP y compararlos con sujetos sanos pareados por edad y sexo. Métodos: Estudio comparativo transversal en pacientes con HAP (grupo I, OMS) con presión de arteria pulmonar media (mPAP) ≥25 mmHg bajo tratamiento con furosemida (40%), espironolactona (53%), Acenocumarol/Warfarina (47%), Bosentan/Ambrisentan (27%), Sildenafil (80%), iloprost (7%) y digoxina (13%). Los sujetos controles correspondieron a sujetos asintomáticos sanos sin enfermedad cardiovascular, cardiopatía estructural ni pulmonar (n=14). En todos los pacientes se determinó mPAP, proBNP, resistencia vascular pulmonar (RVP, WU), presión capilar pulmonar (PCP, mmHg), gasto cardíaco (L/min), capacidad funcional por test de caminata 6 minutos (TC6M), cambio del área fraccional del ventrículo derecho VD (FAC, %). Se utilizó prueba t de Student y programa estadístico SPSS10.0. Un valor de p < 0,05 fue considerado como estadísticamente significativo. Resultados: Los pacientes ingresados al estudio mostraron: etiología de la HAP, idiopática (86,7%), VIH (13,3%), capacidad funcional I (6,2%), II (68,3) y III (25%) y promedio mPAP 51,3±1,9. Pacientes con HAP (grupo I, OMS) versus sujetos sanos mostraron disminución significativa de FAC, actividad plasmática de la ECA2 y niveles circulantes de Ang-(1-9). En la vía clásica del RAAS pacientes con HAP mostraron mayor actividad plasmática de ECA y niveles circulantes e Ag II. Correlaciones significativas se encontraron entre niveles de Ang-(1-9) y mPAP (r = -0.701, p < 0,001) y Ang-(1-9) vs FAC (r = 0.549, p < 0,01). Conclusiones: En pacientes con HAP (grupo I, OMS), los niveles circulantes de Ang-(1-9) están significativamente disminuidos y se asocian inversamente con la PAP, severidad del remodelamiento y disfunción del ventrículo derecho. El uso terapéutico de Ang-(1-9) como agente vasodilatador y cardioprotector podría ser relevante y potencialmente útil, desde una perspectiva clínica, en la HAP. Ang-(1-9) podría reducir la PAP y mejorar el remodelamiento vascular y del ventrículo derecho en la HAP. Por lo tanto, este péptido podría ser útil como blanco terapéutico en la HAP.

ABSTRACTS: Classic renin-angiotensis pathway (RAP) is activated in patients with pulmonary artery hypertension (PAH). We have previously shown that in patients with post myocardial infarction systolic dysfunction the activation of RAP mediated by angiotensin converting enzyme (ACE) and angiotensin II (Ang II) is inversely correlated with the parallel RAP axis mediated by homologous ACE (ACE2) and by the vasoactive and cardioprotective peptide Ang-(1-9). Pre clinical studies show that administration of Ang-(1-9) leads to a favorable ventricular remodelling. At present there is no information regarding levels of Ang-(1-9) in PAH patients compared to healthy subjects. Methods: 16 PAH patients (WHO group 1), with mean PA pressure > 25mmHg being treated with furosemide (40%), Bosentan/Ambrisentan (27%), Sildenafil (80%), iloprost (7%) were compared with healthy subjects (n=14). mPAP, pro BNP, pulmonary vascular resistance (Wu), pulmonary capillary pressure (PCP mmHg), cardiac output (L/min), functional capacity (6 min walking test) (6mWT), and changes in right ventricular fractional area (RV FA), were measured in all subjects. Results: In HAP subjects, the eiotology of PAH was unknown in 87%, or HIV (13%). Functional class was I (6.2 %), II (68.3%) or III (25%). Mean PAP was 51.3±1.9. Compared to healthy subjects, PAH patients had significantly lower RV FA, ACE2 and Ang-(19) levels. Also they had greater ACE plasma activity and AngII circulating levels. Significant correlations were found between Ang-(1-9) and mPAP (-0.701, p < 0,001) and between Ang-(1-9) and RV FA (r = 0.549, p < 0,01). Conclusion: group I PAH subjects, circulating levels of Ang-(1-9) are significantly lower than in healthy subjects and are inversely related to PAP, severity of ventricular remodeling and right ventricular dysfunction. The use of Ang-(1-9) as a vasodilator and cardioprotector agent could be clinically useful in PAH subjects.

En el modelo preclínico de insuficiencia cardíaca por disfunción sistólica en ratón (coartación de aorta torácica) la velocidad de flujo carotídeo determinada precozmente se asocia a función ventricular izquierda tardía / Carotid flow velocity is associated to late ventricular function in mice with preclinic systolic dysfunction induced by thoracic aortic coarctation

Resumen: Los modelos experimentales de falla cardíaca con fracción de eyección disminuida en murinos son pocos. Uno de estos modelos es el de coartación de la aorta torácica en el arco aórtico (COA) en ratones. Un aspecto importante en su desarrollo es la evaluación precoz del procedimiento y su relación con la función sistólica posterior. En este sentido, las velocidades de flujo carotídeo y la relación entre ambos flujos (derecho, pre-coartación; izquierdo post coartación) pueden permitir evaluar tempranamente la precisión del procedimiento y relacionarse más tardíamente con la función sistólica VI. Nuestro objetivo fue comparar precozmente (semana 2 post operatoria) las velocidades de flujo en ambas carótidas (Doppler continuo) y tardíamente (semana 5 postoperatoria) la función sistólica VI (Ecocardiograma de superficie) en ratones seudocoartados o sham (n= 6) vs ratones COA (n = 12). Se confirmó una diferencia estadísticamente significativa en la relación de velocidades de flujo entre ambas carótidas medida precozmente entre los ratones sham y COA (1,1 ± 0,1 vs 2,5 ± 0,5, p< 0,001), lo que se correlacionó con un deterioro significativo de la función sistólica del ventrículo izquierdo evaluada a las 5 semanas en los ratones COA. Conclusión: En este modelo preclínico de falla cardíaca por sobrecarga de presión con fracción de eyección VI disminuida en ratón, el aumento precoz de la velocidad de flujo en la arteria carótida derecha (pre-coartación en el modelo COA) y sobre todo de la relación entre las velocidades de flujo carotídeo entre ambas carótidas se asocia a deterioro importante de la función sistólica VI cinco semanas después de efectuada la COA, lo que permite predecir la efectividad del procedimiento en este modelo experimental.

Abstract: There are few experimental models of heart failure with reduced ejection fraction in murines. One of these models is transverse aortic coarctation (TAC) in mice. However, an important challenge in its development is the early evaluation of the procedure and its relationship with late systolic LV function. In this sense, carotid flow velocities and the relationship between both (right, precoarctation, left post-coarctation) may allow early evaluation of the accuracy of the procedure and be related to late LV systolic function. The aim was to compare early (week 2 post-operative) flow velocities determined in both carotid arteries (by continuous Doppler) with late (week 5 postoperative) LV systolic function (by echocardiogram) in sham (n= 6) vs. TAC (n: 12) mice. We confirmed a statistically significant difference in the early ratio of carotid flow velocities (left/right common carotid velocity ratio) between sham and TAC mice (1.1 ± 0.1 vs 2.5 ± 0.5, p< 0.001) and this correlated well with a deteriorated left ventricular function in the TAC mice after 5 weeks. In this preclinical model of cardiac failure due to pressure overload with reduced LV ejection fraction in the mouse, the early increase in right carotid flow velocity (precoarctation) and especially the relationship between precoarctation/postcoarctation carotid flow velocities is associated with significant impairment of LV systolic function five weeks after the TAC, which allows to predict the effectiveness of the procedure in this experimental model.

Nanoparticles for diagnosis and therapy of atherosclerosis and myocardial infarction: evolution toward prospective theranostic approaches.

Cardiovascular diseases are the leading cause of death worldwide. Despite preventive efforts, early detection of atherosclerosis, the common pathophysiological mechanism underlying cardiovascular diseases remains elusive, and overt coronary artery disease or myocardial infarction is often the first clinical manifestation. Nanoparticles represent a novel strategy for prevention, diagnosis, and treatment of atherosclerosis, and new multifunctional nanoparticles with combined diagnostic and therapeutic capacities hold the promise for theranostic approaches to this disease. This review focuses on the development of nanosystems for therapy and diagnosis of subclinical atherosclerosis, coronary artery disease, and myocardial infarction and the evolution of nanosystems as theranostic tools. We also discuss the use of nanoparticles in noninvasive imaging, targeted drug delivery, photothermal therapies together with the challenges faced by nanosystems during clinical translation.

Label-Free Graphene Oxide-Based Surface Plasmon Resonance Immunosensor for the Quantification of Galectin-3, a Novel Cardiac Biomarker.

We report the first optical biosensor for the novel and important cardiac biomarker, galectin-3 (Gal3), using the anti-Gal3 antibody as a biorecognition element and surface plasmon resonance (SPR) for transducing the bioaffinity event. The immunosensing platform was built at a thiolated Au surface modified by self-assembling four bilayers of poly(diallyldimethylammonium chloride) and graphene oxide (GO), followed by the covalent attachment of 3-aminephenylboronic acid (3ABA). The importance of GO, both as the anchoring point of the antibody and as a field enhancer for improving the biosensor sensitivity, was critically discussed. The advantages of using 3ABA to orientate the anti-Gal3 antibody through the selective link to the Fc region were also demonstrated. The new platform represents an interesting alternative for the label-free biosensing of Gal3 in the whole range of clinically relevant concentrations (linear range between 10.0 and 50.0 ng mL-1, detection limit of 2.0 ng mL-1) with successful application for Gal3 biosensing in enriched human serum samples.

A new role for HERPUD1 and ERAD activation in osteoblast differentiation and mineralization.

Bone integrity depends on a finely tuned balance between bone synthesis by osteoblasts and resorption by osteoclasts. The secretion capacity of mature osteoblasts requires strict control of proteostasis. Endoplasmic reticulum-associated degradation (ERAD) prevents the accumulation of unfolded ER proteins via dislocation to the cytosol and degradation by the proteasome. The ER membrane protein, homocysteine-inducible endoplasmic reticulum protein with ubiquitin-like domain 1 (HERPUD1), is a key component of the ERAD multiprotein complex which helps to stabilize the complex and facilitate the efficient degradation of unfolded proteins. HERPUD1 expression is strongly up-regulated by the unfolded protein response and cellular stress. The aim of the current study was to establish whether HERPUD1 and ERAD play roles in osteoblast differentiation and maturation. We evaluated preosteoblastic MC3T3-E1 cell and primary rat osteoblast differentiation by measuring calcium deposit levels, alkaline phosphatase activity, and runt-related transcription factor 2 and osterix expression. We found that ERAD and proteasomal degradation were activated and that HERPUD1 expression was increased as osteoblast differentiation progressed. The absence of HERPUD1 blocked osteoblast mineralization in vitro and significantly reduced alkaline phosphatase activity. In contrast, HERPUD1 overexpression activated the osteoblast differentiation program. Our results demonstrate that HERPUD1 and ERAD are important for the activation of the osteoblast maturation program and may be useful new targets for elucidating bone physiology.-Américo-Da-Silva, L., Diaz, J., Bustamante, M., Mancilla, G., Oyarzún, I., Verdejo, H. E., Quiroga, C. A new role for HERPUD1 and ERAD activation in osteoblast differentiation and mineralization.

Inhibition of mitochondrial fission prevents hypoxia-induced metabolic shift and cellular proliferation of pulmonary arterial smooth muscle cells.

Chronic hypoxia exacerbates proliferation of pulmonary arterial smooth muscle cells (PASMC), thereby reducing the lumen of pulmonary arteries. This leads to poor blood oxygenation and cardiac work overload, which are the basis of diseases such as pulmonary artery hypertension (PAH). Recent studies revealed an emerging role of mitochondria in PAH pathogenesis, as key regulators of cell survival and metabolism. In this work, we assessed whether hypoxia-induced mitochondrial fragmentation contributes to the alterations of both PASMC death and proliferation. In previous work in cardiac myocytes, we showed that trimetazidine (TMZ), a partial inhibitor of lipid oxidation, stimulates mitochondrial fusion and preserves mitochondrial function. Thus, here we evaluated whether TMZ-induced mitochondrial fusion can prevent human PASMC proliferation in an in vitro hypoxic model. Using confocal fluorescence microscopy, we showed that prolonged hypoxia (48h) induces mitochondrial fragmentation along with higher levels of the mitochondrial fission protein DRP1. Concomitantly, both mitochondrial potential and respiratory rates decreased, indicative of mitochondrial dysfunction. In accordance with a metabolic shift towards non-mitochondrial ATP generation, mRNA levels of glycolytic markers HK2, PFKFB2 and GLUT1 increased during hypoxia. Incubation of PASMC with TMZ, prior to hypoxia, prevented all these changes and precluded the increase in PASMC proliferation. These findings were also observed using Mdivi-1 (a pharmacological DRP1 inhibitor) or a dominant negative DRP1 K38A as pre-treatments. Altogether, our data indicate that TMZ exerts a protective role against hypoxia-induced PASMC proliferation, by preserving mitochondrial function, thus highlighting DRP1-dependent morphology as a novel therapeutic approach for diseases such as PAH.

Galectina-3: experiencia en pacientes chilenos con diagnóstico de insuficiencia cardíaca descompensada / Galectin-3 levels in patients hospitalized for decompensated heart failure

Background: Galectin-3 (Gal-3) is a mediator of myocardial fibrosis involved in cardiac remodeling and a potential new prognosis marker in heart failure (HF). Aim: To measure Gal-3 at the moment of discharge in patients hospitalized for HF and its association with different variables. Material and Methods: Patients hospitalized for decompensated HF from four hospitals between August 2014 and March 2015, were included. Demographic, clinical and laboratory variables were recorded at the time of admission. At discharge, a blood sample was withdrawn to measure Gal-3 and brain natriuretic propeptide (Pro-BNP). Patients were separated in two groups, according to the level of Gal-3 (using a cutoff value of 17.8 ng/mL), comparing clinical and laboratory values between groups. Results: We included 52 patients with HF aged 70 ± 17 years (42% females). Functional capacity was III-IV in 46% of patients and the ejection fraction was 34.9 ± 13.4%. Pro-BNP values at discharge were 5,323 ± 8,665 pg/mL. Gal-3 values were 23.8 ± 16.6 ng/mL. Sixty percent of patients had values over 17.8 ng/mL. Those with elevated Gal-3 levels were older (75 ±16 and 62 ± 15 years, respectively, p = 0.025) and were hypertensive in a higher proportion (90.5% and 57.1% respectively, p = 0.021). Conclusions: In patients hospitalized for HF, Gal-3 levels are higher in older and hypertensive subjects.

Increased C-reactive protein plasma levels are not involved in the onset of post-operative atrial fibrillation.

BACKGROUND: Increased inflammation biomarkers plasma levels, including C-reactive protein (CRP), have been associated with the initiation and perpetuation of atrial fibrillation (AF). However, it is not known whether an increased CRP plasma level, without concomitant inflammation, is sufficient to induce AF. We investigated whether higher CRP plasma levels, determined by the presence of +219G>A CRP gene polymorphism, is associated with an increased risk of post-operative AF. METHODS: One hundred and fifteen adult patients submitted to elective coronary surgery were genotyped for the CRP +219G>A polymorphism. CRP plasma levels were determined by enzyme-linked immunosorbent assay. RESULTS: CRP plasma levels before surgery were higher in GG than in GA+AA patients (3.4±3.1 vs. 1.7±1.8, p<0.015). Thirteen percent of the patients presented post-operative AF. Despite the positive correlation between the polymorphism and CRP levels, there was no significant difference in the occurrence of post-operative AF between the different genotypes. CONCLUSIONS: These results suggest that increased CRP plasma levels that are not associated with an inflammatory process are not sufficient to trigger AF after cardiac surgery.

[Frailty in patients admitted to hospital with acute decompensated heart failure]. / Factores asociados a fragilidad en pacientes hospitalizados con insuficiencia cardiaca descompensada.

BACKGROUND: Frailty is a geriatric syndrome characterized by a progressive impairment in the subjects’ ability to respond to environmental stress. Frailty is more commonly found in heart failure (HF) patients than in general population and it is an independent predictor of rehospitalization, emergency room visits and death. AIM: To estimate the prevalence of frailty in patients with decompensated HF admitted to four hospitals in Santiago, Chile. MATERIAL AND METHODS: Cross-sectional study. Subjects aged 60 or older consecutively admitted for decompensated HF to the study centers between August 2014 and March 2015 were included. Frailty was defined as the presence of three or more of the following criteria: unintended weight loss, muscular weakness, depression symptoms (exhaustion), reduced gait speed and low physical activity. Independent variables were tested for association using simple logistic regression. Variables associated with frailty (p < 0.05) were included in a multiple logistic regression model. RESULTS: Seventy-nine subjects were included. The prevalence of frailty was 50.6%. Frail patients were mostly female (52.6%) and older than non-frail subjects (73.7± 7.9 vs 68.2 ± 7.1; p < 0.003). Independent predictors of frailty were age (Odds raio (OR) 1.10; 95% confidence intervals (CI): 1.03-1.17), quality of life measured with the Minnesota Living with Heart Failure Questionnaire (OR 1.07; IC95%: 1.03-1.11), previous hospitalizations (OR 2.56; 95%CI: 1.02-6.43) and number of medications (OR 4.46; 95%CI: 1.11-17.32). CONCLUSIONS: The prevalence of frailty in patients admitted to the hospital for decompensated heart failure is high. Age, quality of life, hospitalizations and polypharmacy were factors associated with frailty in this group of participants.