Circulating MicroRNAs and myocardial involvement severity in chronic Chagas cardiomyopathy.

Background Chronic Chagas Cardiomyopathy (CCM) is characterized by a unique pathophysiology in which inflammatory, microvascular and neuroendocrine processes coalesce in the development of one of the most severe cardiomyopathies affecting humans. Despite significant advances in understanding the molecular mechanisms involved in this disease, scarce information is available regarding microRNAs and clinical parameters of disease severity. We aimed to evaluate the association between circulating levels of six microRNAs with markers of myocardial injury and prognosis in this population. Methods Patients with CCM and reduced ejection fraction were included in a prospective exploratory cohort study. We assessed the association of natural log-transformed values of six circulating microRNAs (miR-34a-5p, miR-208a-5p, miR-185-5p, miR-223-5p, let-7d-5p, and miR-454-5p) with NT-proBNP levels and echocardiographic variables using linear regression models adjusted for potential confounders. By using Cox Proportional Hazard models, we examined whether levels of microRNAs could predict a composite outcome (CO), including all-cause mortality, cardiac transplantation, and implantation of a left ventricular assist device (LVAD). Finally, for mRNAs showing significant associations, we predicted the target genes and performed pathway analyses using Targetscan and Reactome Pathway Browser. Results Seventy-four patients were included (59% males, median age: 64 years). After adjustment for age, sex, body mass index, and heart failure medications, only increasing miR-223-5p relative expression levels were significantly associated with better myocardial function markers, including left atrium area (Coef. -10.2; 95% CI -16.35; -4.09), end-systolic (Coef. -45.3; 95% CI -74.06; -16.61) and end-diastolic volumes (Coef. -46.1; 95% CI -81.99; -10.26) of the left ventricle. Moreover, we observed that higher miR-223-5p levels were associated with better left-ventricle ejection fraction and lower NT-proBNP levels. No associations were observed between the six microRNAs and the composite outcome. A total of 123 target genes for miR-223-5p were obtained. From these, several target pathways mainly related to signaling by receptor tyrosine kinases were identified. Conclusions The present study found an association between miR-223-5p and clinical parameters of CCM, with signaling pathways related to receptor tyrosine kinases as a potential mechanism linking low levels of miR-223-5p with CCM worsening

Variables pre-analíticas que afectan las concentraciones de homocisteína: aplicación para biobancos con fines de investigación

Objetivo: El presente estudio evaluó el impacto de las variables pre-analíticas sobre las concentraciones séricas de la Homocisteína, y su posible aplicación en biobancos con fines de investigación.   Metodología: En diez adultos voluntarios auto declarados sanos, se tomaron muestras de sangre periférica bajo diferentes condiciones de ayuno, posición de toma de la muestra (supino versus sentada) y diferentes intervalos de tiempo entre la toma y la separación definitiva de componentes. Todas las alícuotas fueron almacenadas a -800C en el biobanco hasta el momento de ser procesadas. La medición de homocisteína se hizo por duplicado en Immulite® 2000. Se realizó análisis de concordancia por medio de coeficiente de Lin (σ) y MANOVA.   Resultados: La medición de homocisteína es altamente reproducible (σ=0.908, IC95% 0.861 a 0.955), sin que el ayuno o el tiempo de centrifugación de la muestra afecte su concentración. Sin embrago, la posición al momento de la toma de muestra, implica una reducción media de 14.2% (IC95% 8.4% a 20.0%) en la concentración de Homocisteína en poción decúbito supino versus la toma en posición sentado.   Conclusión: La homocisteína es un biomarcador estable, sin que su valor se vea alterado por variables pre-analíticas como los tiempos entre toma de muestra, centrifugación y separación de componentes (almacenamiento temporal a 4°C). Sin embargo la postura del participante al momento de la toma de muestra produce una variabilidad significativa. Estos hallazgos reiteran el papel de un biobanco en la estandarización de los procesos de toma, manipulación, almacenamiento y gestión con criterios de excelencia.&nbsp

Pre-analytical variables that affect homocysteine concentrations: Applications for research biobanks

Objetivo: El presente estudio evaluó el impacto de las variables pre-analÍticas sobre las concentraciones séricas de la Homocisteína, y su posible aplicación en biobancos con fines de investigación. Metodología: En diez adultos voluntarios auto declarados sanos, se tomaron muestras de sangre periférica bajo diferentes condiciones de ayuno, posición de toma de la muestra (supino versus sentada) y diferentes intervalos de tiempo entre la toma y la separación definitiva de componentes. Todas las alícuotas fueron almacenadas a -800C en el biobanco hasta el momento de ser procesadas. La medición de homocisteína se hizo por duplicado en Immulite® 2000. Se realizó análisis de concordancia por medio de coeficiente de Lin (σ) y MANOVA. Resultados: La medición de homocisteína es altamente reproducible (σ=0.908, IC95% 0.861 a 0.955), sin que el ayuno o el tiempo de centrifugación de la muestra afecte su concentración. Sin embrago, la posición al momento de la toma de muestra, implica una reducción media de 14.2% (IC95% 8.4% a 20.0%) en la concentración de Homocisteína en poción decúbito supino versus la toma en posición sentado. Conclusión: La homocisteína es un biomarcador estable, sin que su valor se vea alterado por variables pre-analÍticas como los tiempos entre toma de muestra, centrifugación y separación de componentes (almacenamiento temporal a 4°C). Sin embargo la postura del participante al momento de la toma de muestra produce una variabilidad significativa. Estos hallazgos reiteran el papel de un biobanco en la estandarización de los procesos de toma, manipulación, almacenamiento y gestión con criterios de excelencia.Objective: The present study evaluated the impact of pre-analytical variables on serum concentrations of Homocysteine, and its possible application in biobanks for research purposes. Methodology: In ten self-declared healthy adult volunteers, peripheral blood samples were taken under different fasting conditions, sample collection position (supine versus sitting) and different time intervals between collection and definitive separation of components. All aliquots were stored at -800C in the biobank until processed. Homocysteine ​​measurement was done in duplicate on Immulite® 2000. Concordance analysis was performed using Lin's coefficient (σ) and MANOVA. Results: The measurement of homocysteine ​​is highly reproducible (σ=0.908, 95% CI 0.861 to 0.955), without fasting or sample centrifugation time affecting its concentration. However, the position at the time of sampling implies an average reduction of 14.2% (95% CI 8.4% to 20.0%) in the concentration of Homocysteine ​​in the supine position versus taking it in the sitting position. Conclusion: Homocysteine ​​is a stable biomarker, without its value being altered by pre-analytical variables such as the times between sample collection, centrifugation and separation of components (temporary storage at 4°C). However, the participant's posture at the time of sampling produces significant variability. These findings reiterate the role of a biobank in the standardization of collection, handling, storage and management processes with criteria of excellence

A model of metformin mitochondrial metabolism in metachromatic leukodystrophy: first description of human Schwann cells transfected with CRISPR-Cas9

Metachromatic leukodystrophy is a neurological lysosomal deposit disease that affects public health despite its low incidence in the population. Currently, few reports are available on pathophysiological events related to enzyme deficiencies and subsequent sulfatide accumulation. This research aims to examine the use of metformin as an alternative treatment to counteract these effects. This was evaluated in human Schwann cells (HSCs) transfected or non-transfected with CRISPR-Cas9, and later treated with sulfatides and metformin. This resulted in transfected HSCs showing a significant increase in cell reactive oxygen species (ROS) production when exposed to 100 µM sulfatides (p = 0.0007), compared to non-transfected HSCs. Sulfatides at concentrations of 10 to 100 µM affected mitochondrial bioenergetics in transfected HSCs. Moreover, these analyses showed that transfected cells showed a decrease in basal and maximal respiration rates after exposure to 100 µM sulfatide. However, maximal and normal mitochondrial respiratory capacity decreased in cells treated with both sulfatide and metformin. This study has provided valuable insights into bioenergetic and mitochondrial effects of sulfatides in HSCs for the first time. Treatment with metformin (500 µM) restored the metabolic activity of these cells and decreased ROS production

Circulating DHEA-S levels and major cardiovascular outcomes in chronic Chagas cardiomyopathy: A prospective cohort study.

OBJECTIVE To analyze the association of circulating dehydroepiandrosterone sulfate (DHEA-S) levels with cardiovascular outcomes in patients with chronic Chagas cardiomyopathy (CCM) diagnosis. BACKGROUND DHEA-S is among the main endogenous steroid hormones. Some studies have suggested a relevant role of this hormone in infections and the setting of CCM. Nevertheless, no study has evaluated the prognostic role of DHEA-S in CCM patients. METHODS Prospective cohort study. Patients with CCM and reduced ejection fraction were included. We explored the association of DHEA-S levels with NT-proBNP levels and echocardiographic variables using linear regression models. Next, by using Cox Proportional Hazard models, we examined whether levels of DHEA-S could predict a composite outcome (CO) including all-cause mortality, cardiac transplantation, and implantation of a left ventricular assist device (LVAD). RESULTS Seventy-four patients were included (59% males, median age: 64 years). After adjustment for confounding factors, high DHEA-S levels were associated with better LVEF, lower left atrium volume, end-systolic volume of the left ventricle and lower NT-proBNP levels. 43% of patients experienced the CO during a median follow-up of 40 months. Increased levels of DHEA-S were associated with a lower risk of developing the CO (HR 0.43; 95%CI 0.21-0.86). Finally, adding DHEA-S to the multivariate model did not improve the prediction of the CO, but substituting NT-proBNP in the model with DHEA-S showed similar performance. CONCLUSIONS In patients with CCM, higher DHEA-S levels were associated with lower mortality, heart transplantation, and LVAD implantation. Further larger studies are required to confirm our results and assess causality