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1.
bioRxiv ; 2024 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-38659956

RESUMEN

Recent developments in cardiac macrophage biology have broadened our understanding of the critical functions of macrophages in the heart. As a result, there is further interest in understanding the independent contributions of distinct subsets of macrophage to cardiac development and function. Here, we demonstrate that genetic loss of interferon regulatory factor 8 (Irf8)-positive embryonic-derived macrophages significantly disrupts cardiac conduction, chamber function, and innervation in adult zebrafish. At 4 months post-fertilization (mpf), homozygous irf8st96/st96 mutants have significantly shortened atrial action potential duration and significant differential expression of genes involved in cardiac contraction. Functional in vivo assessments via electro- and echocardiograms at 12 mpf reveal that irf8 mutants are arrhythmogenic and exhibit diastolic dysfunction and ventricular stiffening. To identify the molecular drivers of the functional disturbances in irf8 null zebrafish, we perform single cell RNA sequencing and immunohistochemistry, which reveal increased leukocyte infiltration, epicardial activation, mesenchymal gene expression, and fibrosis. Irf8 null hearts are also hyperinnervated and have aberrant axonal patterning, a phenotype not previously assessed in the context of cardiac macrophage loss. Gene ontology analysis supports a novel role for activated epicardial-derived cells (EPDCs) in promoting neurogenesis and neuronal remodeling in vivo. Together, these data uncover significant cardiac abnormalities following embryonic macrophage loss and expand our knowledge of critical macrophage functions in heart physiology and governing homeostatic heart health.

2.
Photochem Photobiol ; 96(6): 1294-1313, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32692856

RESUMEN

A comparative study of the effect of low-intensity laser radiation in green (λ = 532 nm) and red (λ = 632.8 nm) spectral regions at equal average irradiance (3 mW cm-2 ) on functional characteristics of Siberian sturgeon spermatozoa is carried out. Confirmation of the photobiomodulation effect of the radiation is obtained by analyzing spermatozoa motility, percentage of motile spermatozoa and fertilization rate. It is shown that, depending on the energy dose, the laser radiation in red and green spectral regions can have both stimulatory and inhibitory effects on spermatozoa motility. Contrary to popular belief that the short-wavelength radiation has great prospects in reproductive biotechnologies (due to more efficient absorption of radiation by cellular chromophores and increased generation of ROS), convincing evidence of a more pronounced stimulatory effect of radiation in the red spectral region was obtained. For the first time, metal-free porphyrins capable of acting as endogenous photosensitizers generating ROS were detected and identified in animal sperm. Using luminol-dependent chemiluminescence, it is shown that the increased production of ROS capable of exerting an inhibitory effect on biological systems at high concentrations is among the possible reasons for reduction in the stimulatory effect of radiation when moving from red to green spectral region.


Asunto(s)
Rayos Láser , Análisis Espectral/métodos , Espermatozoides/efectos de la radiación , Animales , Relación Dosis-Respuesta en la Radiación , Peces , Masculino , Especies Reactivas de Oxígeno/metabolismo , Espermatozoides/fisiología
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