Changes in human skin composition due to intrinsic aging: a histologic and morphometric study.

Skin represents the main barrier against the external environment, but also plays a role in human relations, as one of the prime determinants of beauty, resulting in a high consumer demand for skincare-related pharmaceutical products. Given the importance of skin aging in both medical and social spheres, the present research aims to characterize microscopic changes in human skin composition due to intrinsic aging (as opposed to aging influenced by external factors) via histological analysis of a photoprotected body region. Samples from 25 autopsies were taken from the periumbilical area and classified into four age groups: group 1 (0-12 years), group 2 (13-25 years), group 3 (26-54 years), and group 4 (≥ 55 years). Different traditional histological (hematoxylin-eosin, Masson's trichrome, orcein, toluidine, Alcian blue, and Feulgen reaction) and immunohistochemical (CK20, CD1a, Ki67, and CD31) stains were performed. A total of 1879 images photographed with a Leica DM3000 optical microscope were morphometrically analyzed using Image ProPlus 7.0 for further statistical analysis with GraphPad 9.0. Our results showed a reduction in epidermis thickness, interdigitation and mitotic indexes, while melanocyte count was raised. Papillary but not reticular dermis showed increased thickness with aging. Specifically, in the papillary layer mast cells and glycosaminoglycans were expanded, whereas the reticular dermis displayed a diminution in glycosaminoglycans and elastic fibers. Moreover, total cellularity and vascularization of both dermises were diminished with aging. This morphometric analysis of photoprotected areas reveals that intrinsic aging significantly influences human skin composition. This study paves the way for further research into the molecular basis underpinning these alterations, and into potential antiaging strategies.

Novel Fibrillar and Non-Fibrillar Collagens Involved in Fibrotic Scar Formation after Myocardial Infarction.

Following myocardial infarction (MI), adverse remodeling depends on the proper formation of fibrotic scars, composed of type I and III collagen. Our objective was to pinpoint the participation of previously unreported collagens in post-infarction cardiac fibrosis. Gene (qRT-PCR) and protein (immunohistochemistry followed by morphometric analysis) expression of fibrillar (types II and XI) and non-fibrillar (types VIII and XII) collagens were determined in RNA-sequencing data from 92 mice undergoing myocardial ischemia; mice submitted to permanent (non-reperfused MI, n = 8) or transient (reperfused MI, n = 8) coronary occlusion; and eight autopsies from chronic MI patients. In the RNA-sequencing analysis of mice undergoing myocardial ischemia, increased transcriptomic expression of collagen types II, VIII, XI, and XII was reported within the first week, a tendency that persisted 21 days afterwards. In reperfused and non-reperfused experimental MI models, their gene expression was heightened 21 days post-MI induction and positively correlated with infarct size. In chronic MI patients, immunohistochemistry analysis demonstrated their presence in fibrotic scars. Functional analysis indicated that these subunits probably confer tensile strength and ensure the cohesion of interstitial components. Our data reveal that novel collagens are present in the infarcted myocardium. These data could lay the groundwork for unraveling post-MI fibrotic scar composition, which could ultimately influence patient survivorship.

Extracellular vesicles from dental pulp mesenchymal stem cells modulate macrophage phenotype during acute and chronic cardiac inflammation in athymic nude rats with myocardial infarction.

BACKGROUND/AIMS: Extracellular vesicles (EVs) derived from dental pulp mesenchymal stem cells (DP-MSCs) are a promising therapeutic option for the treatment of myocardial ischemia. The aim of this study is to determine whether MSC-EVs could promote a pro-resolving environment in the heart by modulating macrophage populations. METHODS: EVs derived from three independent biopsies of DP-MSCs (MSC-EVs) were isolated by tangential flow-filtration and size exclusion chromatography and were characterized by omics analyses. Biological processes associated with these molecules were analyzed using String and GeneCodis platforms. The immunomodulatory capacity of MSC-EVs to polarize macrophages towards a pro-resolving or M2-like phenotype was assessed by evaluating surface markers, cytokine production, and efferocytosis. The therapeutic potential of MSC-EVs was evaluated in an acute myocardial infarction (AMI) model in nude rats. Infarct size and the distribution of macrophage populations in the infarct area were evaluated 7 and 21 days after intramyocardial injection of MSC-EVs. RESULTS: Lipidomic, proteomic, and miRNA-seq analysis of MSC-EVs revealed their association with biological processes involved in tissue regeneration and regulation of the immune system, among others. MSC-EVs promoted the differentiation of pro-inflammatory macrophages towards a pro-resolving phenotype, as evidenced by increased expression of M2 markers and decreased secretion of pro-inflammatory cytokines. Administration of MSC-EVs in rats with AMI limited the extent of the infarcted area at 7 and 21 days post-infarction. MSC-EV treatment also reduced the number of pro-inflammatory macrophages within the infarct area, promoting the resolution of inflammation. CONCLUSION: EVs derived from DP-MSCs exhibited similar characteristics at the omics level irrespective of the biopsy from which they were derived. All MSC-EVs exerted effective pro-resolving responses in a rat model of AMI, indicating their potential as therapeutic agents for the treatment of inflammation associated with AMI.

Efecto del suero aislado de pacientes con infarto agudo de miocardio con elevación del segmento ST en las células endoteliales / Effect of serum from patients with ST-segment elevation myocardial infarction on endothelial cells

Introducción y objetivos La reperfusión coronaria produce un daño en la microcirculación y, en concreto, las células endoteliales. Este estudio evalúa el efecto del suero aislado tras la revascularización de pacientes con un infarto agudo de miocardio con elevación del segmento ST (IAMCEST) en la viabilidad celular, el grado de permeabilidad endotelial in vitro y la asociación de estos parámetros con una mayor extensión de los índices de resonancia magnética cardiaca (RMC) relacionados con el daño por reperfusión (edema, hemorragia y obstrucción microvascular). Métodos Se incubaron células endoteliales de arteria coronaria humana con suero aislado 24 h tras la revascularización de 43 pacientes con IAMCEST evaluados mediante RMC y 14 sujetos de control. Se testó el efecto del suero de pacientes con IAMCEST en la pérdida de viabilidad celular por activación de la apoptosis y la necrosis, así como en la permeabilidad y la estructura de la monocapa endotelial. Resultados El suero de pacientes con IAMCEST aumentó la apoptosis (p <0,01) y la necrosis (p <0,05) de células endoteliales de arteria coronaria humana y causó un incremento de la permeabilidad de la monocapa endotelial in vitro (p <0,01) debido a mayores espacios intercelulares (p <0,05 frente a los controles). Una mayor necrosis inducida por suero se asoció con más permeabilidad endotelial in vitro (p <0,05) y con una mayor extensión de los principales índices de daño tras reperfusión y mayor tamaño de infarto. Conclusiones El suero tras la reperfusión de pacientes con IAMCEST induce la apoptosis y la necrosis in vitro de las células endoteliales y la permeabilidad endotelial. Cuanto más potente sea el efecto inductor de necrosis, más deletéreas son las consecuencias en cuanto al daño estructural resultante. (AU)

Introduction and objectives Clinical and experimental studies have shown that, in patients with reperfused ST-segment elevation myocardial infarction (STEMI), abnormalities in the endothelial monolayer are initiated during ischemia but rapidly intensify upon restoration of blood perfusion to the ischemic area. We aimed to evaluate the effect of serum isolated after revascularization from STEMI patients on the degree of endothelial permeability in vitro, by promoting endothelial cell apoptosis and necrosis in vitro. We also investigated the association between the percentage of serum-induced endothelial cell apoptosis or necrosis in vitro and the extent of cardiovascular magnetic resonance (CMR)-derived parameters of reperfusion injury (edema, hemorrhage, and microvascular obstruction). Methods Human coronary artery endothelial cells were incubated with serum isolated 24hours after revascularization from 43 STEMI patients who underwent CMR and 14 control participants. We assessed the effect of STEMI serum on activation of apoptosis and necrosis, as well as on the permeability and structure of the endothelial monolayer. Results Serum from STEMI patients increased apoptosis (P <.01) and necrosis (P <.05) in human coronary artery endothelial cells and caused increased permeability of the endothelial monolayer in vitro (P <.01), due to enlarged intercellular spaces (P <.05 vs control in all cases). Higher serum-induced necrosis was associated with greater endothelial permeability in vitro (P <.05) and with more extensive CMR-derived indices of reperfusion injury and infarct size. Conclusions Postreperfusion serum activates necrosis and apoptosis in endothelial cells and increases the degree of endothelial permeability in vitro. The more potent the necrosis-triggering effect of serum, the more deleterious the consequences in terms of the resulting cardiac structure. (AU)

Solitary fibrous tumor: Can the new Huang risk stratification system for orbital tumors improve prognostic accuracy in other tumor locations?

Solitary fibrous tumors (SFTs) are known for their heterogeneous morphology, characterized by a variety of cell shapes and different growth patterns. They can also arise in various anatomical locations, most commonly in extremities and deep soft tissues. Despite this diversity in morphology and location, all SFTs share a common molecular signature involving the NAB2::STAT6 gene fusion. Due to their unpredictable clinical behavior, establishing prognostic factors is crucial. This study aims to evaluate an orbital risk stratification system (RSS) proposed by Huang et al. for use in extraorbital SFTs using a database of 97 cases. The Huang model takes into consideration tumor size, mitotic figures, Ki-67 index, and dominant constituent cell (DCC) as key variables. Survival analysis confirmed the model's predictive value, with higher-risk scores being associated with poorer outcomes. However, in contrast to the orbital SFTs studied by Huang et al., our study did not find a correlation between tumor size and recurrence in extraorbital cases. While the Huang model performs slightly better than other RSS, it falls short on achieving statistical significance in distinguishing recurrence risk groups in extraorbital locations. In conclusion, this study validates the Huang RSS for use in extraorbital SFTs and underscores the importance of considering DCC, mitotic count, and Ki-67 together. However, we found that including tumor size in this model did not improve prognostic significance in extraorbital SFTs. Despite the benefits of this additional RSS, vigilant monitoring remains essential, even in cases classified as low-risk due to the inherent unpredictability of SFT clinical outcomes.

Implicación de la isoforma antiangiogénica VEGF-A165b en la angiogénesis y la función sistólica tras un infarto de miocardio reperfundido / Role of antiangiogenic VEGF-A165b in angiogenesis and systolic function after reperfused myocardial infarction

Introducción y objetivos La angiogénesis participa en la restauración de la microcirculación después de un infarto agudo de miocardio (IAM). El objetivo de este estudio es explorar el papel que juega la isoforma anti-angiogénica del factor de crecimiento endotelial vascular (VEGF)-A165b y explorar su potencial como terapia coadyuvante a la reperfusión coronaria. Métodos Se realizaron dos modelos murinos de IAM: a) ligadura permanente de la arteria coronaria (IAM no reperfundido) y b) oclusión transitoria durante 45 minutos de la arteria coronaria seguida de reperfusión (IAM reperfundido); en ambos modelos, se realizó a los animales una ecocardiografía previa a la eutanasia el día 21 pos-IAM. Se determinaron los niveles séricos y miocárdicos de VEGF- A165b. En ambos modelos experimentales se evaluó la implicación funcional y estructural del bloqueo de esta isoforma. En una cohorte de 104 pacientes con IAM con elevación del segmento ST se cuantificaron los niveles circulantes de VEGF-A165b y se estudió su asociación con la fracción de eyección del ventrículo izquierdo determinada mediante resonancia magnética cardiaca a los 6 meses del IAM, así como con la aparición de eventos adversos (muerte, insuficiencia cardiaca o reinfarto) durante el seguimiento. Resultados En ambos modelos, los niveles séricos y tisulares de VEGF-A165b habían aumentado a los 21 días de la inducción del IAM. Además, existía una correlación negativa entre los valores circulantes de VEGF-A165b y la función sistólica evaluada mediante ecocardiografía. El bloqueo in vivo de VEGF-A165b se relacionó con una mayor densidad microvascular, menor tamaño de infarto y mejor fracción de eyección en el modelo de IAM reperfundido, pero no en el modelo de IAM no reperfundido. En la cohorte de pacientes, aquellos con unos niveles séricos elevados de VEGF-A165b presentaron una fracción de eyección deprimida y una mayor tasa de eventos adversos. Conclusiones ... (AU)

Introduction and objectives Angiogenesis helps to reestablish microcirculation after myocardial infarction (MI). In this study, we aimed to further understand the role of the antiangiogenic isoform vascular endothelial growth factor (VEGF)-A165b after MI and to explore its potential as a coadjuvant therapy to coronary reperfusion. Methods Two mice MI models were formed: a) permanent coronary ligation (nonreperfused MI); b) transient 45-minute coronary occlusion followed by reperfusion (reperfused MI); in both models, animals underwent echocardiography before euthanasia at day 21 after MI induction. We determined serum and myocardial VEGF-A165b levels. In both experimental MI models, we assessed the functional and structural role of VEGF-A165b blockade. In a cohort of 104 ST-segment elevation MI patients, circulating VEGF-A165b levels were correlated with cardiovascular magnetic resonance-derived left ventricular ejection fraction at 6 months and with the occurrence of adverse events (death, heart failure, and/or reinfarction). Results In both models, circulating and myocardial VEGF-A165b levels were increased 21 days after MI induction. Serum VEGF-A165b levels inversely correlated with systolic function evaluated by echocardiography. VEGF-A165b blockade increased capillary density, reduced infarct size, and enhanced left ventricular function in reperfused, but not in nonreperfused, MI experiments. In patients, higher VEGF-A165b levels correlated with depressed ejection fraction and worse outcomes. Conclusions In experimental and clinical studies, higher serum VEGF-A165b levels are associated with worse systolic function. Their blockade enhances neoangiogenesis, reduces infarct size, and increases ejection fraction in reperfused, but not in nonreperfused, MI experiments. Therefore, VEGF-A165b neutralization represents a potential coadjuvant therapy to coronary reperfusion. (AU)

El suero de seno coronario tras un infarto de miocardio induce angiogénesis y reparación de la obstrucción microvascular. Implicación del factor inducible por hipoxia-1A / Coronary serum obtained after myocardial infarction induces angiogenesis and microvascular obstruction repair. Role of hypoxia-inducible factor-1A

Introducción y objetivos: El objetivo es estudiar la angiogénesis coronaria inducida por el suero coronario y la implicación del factor inducible por hipoxia-1A (FIH-1A) en la reparación de la obstrucción microvascular (OMV) tras un infarto agudo de miocardio (IAM). Métodos: Se indujo un IAM en cerdos mediante oclusión coronaria durante 90 min. Se dividió a los animales entre 1 grupo de control y 4 grupos con IAM: sin reperfusión y 1 min, 1 semana y 1 mes tras la reperfusión. Se cuantificaron la OMV y la densidad microvascular. Se determinó la capacidad angiogénica del suero coronario mediante una prueba de tubulogénesis in vitro. Se determinaron las concentraciones circulantes del FIH-1A, su implicación en el miocardio infartado y el efecto del bloqueo del FIH-1A in vitro. Resultados: En la zona infartada, la microvascularización disminuye tras 90 min de isquemia, la OMV aparece tras 1 min de reperfusión, es máxima 1 semana tras la reperfusión y se resuelve en 1 mes. La capacidad angiogénica del suero aumenta durante la isquemia y 1 min tras la reperfusión (32 ± 4 y 41 ± 9 frente a 3 ± 3 tubos en el grupo de control; p < 0,01). Las concentraciones circulantes del FIH-1A se incrementan durante la isquemia (5 min de isquemia: 273 ± 52 frente a 148 ± 48 pg/ml de los controles; p < 0,01) y se hallan en la microvasculatura de todos los grupos con IAM (sin reperfusión frente a control, el 67 ± 5% frente al 15 ± 17%; p < 0,01). El bloqueo del FIH-1A in vitro reduce la capacidad angiogénica inducida por el suero. Conclusiones: El suero coronario activa la neoangiogénesis desde antes de la reperfusión, y el FIH-1A podría tener un papel crucial. La capacidad angiogénica del suero coronario puede contribuir a la comprensión de la fisiopatología tras el IAM

Introduction and objectives: Microvascular obstruction (MVO) exerts deleterious effects following acute myocardial infarction (AMI). We investigated coronary angiogenesis induced by coronary serum and the role of hypoxia-inducible factor-1A (HIF-1A) in MVO repair. Methods: Myocardial infarction was induced in swine by transitory 90-minute coronary occlusion. The pigs were divided into a control group and 4 AMI groups: no reperfusion, 1 minute, 1 week and 1 month after reperfusion. Microvascular obstruction and microvessel density were quantified. The proangiogenic effect of coronary serum drawn from coronary sinus on endothelial cells was evaluated using an in vitro tubulogenesis assay. Circulating and myocardial HIF-1A levels and the effect of in vitro blockade of HIF-1A was assessed. Results: Compared with control myocardium, microvessel density decreased at 90-minute ischemia, and MVO first occurred at 1 minute after reperfusion. Both peaked at 1 week and almost completely resolved at 1 month. Coronary serum exerted a neoangiogenic effect on coronary endothelial cells in vitro, peaking at ischemia and 1 minute postreperfusion (32 ± 4 and 41 ± 9 tubes vs control: 3 ± 3 tubes; P < .01). Hypoxia-inducible factor-1A increased in serum during ischemia (5-minute ischemia: 273 ± 52 pg/mL vs control: 148 ± 48 pg/mL; P < .01) being present on microvessels of all AMI groups (no reperfusion: 67% ± 5% vs control: 15% ± 17%; P < .01). In vitro blockade of HIF-1A reduced the angiogenic response induced by serum. Conclusions: Coronary serum represents a potent neoangiogenic stimulus even before reperfusion; HIF-1A might be crucial. Coronary neoangiogenesis induced by coronary serum can contribute to understanding the pathophysiology of AMI

Infusión intracoronaria de tioflavina-S para el estudio de la obstrucción microvascular en un modelo de infarto de miocardio / Intracoronary infusion of thioflavin-S to study microvascular obstruction in a model of myocardial infarction

Introducción y objetivos. La obstrucción microvascular produce efectos nocivos después del infarto de miocardio. Con objeto de esclarecer el papel de la lesión por isquemia-reperfusión en la aparición y la dinámica de la obstrucción microvascular, se llevó a cabo un estudio metodológico preliminar para definir con exactitud este proceso en un modelo in vivo. Métodos. Se indujo un infarto de miocardio en cerdos mediante una oclusión de 90 min en la parte media de la arteria coronaria descendente anterior izquierda empleando balones de angioplastia. Se aplicó una infusión intracoronaria de tioflavina-S y se comparó con la instilación tradicional intraaórtica o intraventricular. Se cuantificó el área perfundida por la arteria coronaria coronaria descendente anterior izquierda y la obstrucción microvascular en los grupos sin reperfusión (administración de tioflavina-S a través de la luz de un balón hinchado montado sobre la guía) y con reperfusión de 1 min, 1 semana y 1 mes (administración de tioflavina-S mediante el catéter intracoronario después de deshinchar el balón). Resultados. En comparación con la administración intraaórtica e intraventricular, la infusión intracoronaria de tioflavina-S permitió una evaluación mucho más clara del área perfundida por la arteria coronaria descendente anterior izquierda y de la obstrucción microvascular. La lesión por isquemia-reperfusión tuvo un papel decisivo en la aparición y la dinámica de la obstrucción microvascular. El grupo sin reperfusión presentó una perfusión completamente preservada. Con la misma duración de la oclusión coronaria, la obstrucción microvascular se detectó ya en el grupo de reperfusión de 1 min (14 ± 7%), alcanzó un máximo en el grupo de reperfusión de 1 semana (21 ± 7%) y se redujo significativamente en el grupo de reperfusión de 1 mes (4 ± 3%; p < 0,001). Conclusiones. Se presenta una prueba de concepto del papel crucial que desempeña la lesión por isquemia-reperfusión en la aparición y la dinámica de la obstrucción microvascular. El modelo de cerdo descrito, que emplea inyección intracoronaria de tioflavina-S, permite una caracterización exacta de la obstrucción microvascular después del infarto de miocardio (AU)

Introduction and objectives. Microvascular obstruction exerts deleterious effects after myocardial infarction. To elucidate the role of ischemia-reperfusion injury on the occurrence and dynamics of microvascular obstruction, we performed a preliminary methodological study to accurately define this process in an in vivo model. Methods. Myocardial infarction was induced in swine by means of 90-min of occlusion of the mid left anterior descending coronary artery using angioplasty balloons. Intracoronary infusion of thioflavin-S was applied and compared with traditional intra-aortic or intraventricular instillation. The left anterior descending coronary artery perfused area and microvascular obstruction were quantified in groups with no reperfusion (thioflavin-S administered through the lumen of an inflated over-the-wire balloon) and with 1-min, 1-week, and 1-month reperfusion (thioflavin-S administered from the intracoronary catheter after balloon deflation). Results. In comparison with intra-aortic and intraventricular administration, intracoronary infusion of thioflavin-S permitted a much clearer assessment of the left anterior descending coronary artery perfused area and of microvascular obstruction. Ischemia-reperfusion injury exerted a decisive role on the occurrence and dynamics of microvascular obstruction. The no-reperfusion group displayed completely preserved perfusion. With the same duration of coronary occlusion, microvascular obstruction was already detected in the 1-min reperfusion group (14% ± 7%), peaked in the 1-week reperfusion group (21% ± 7%), and significantly decreased in the 1-month reperfusion group (4% ± 3%; P < .001). Conclusions. We present proof-of-concept evidence on the crucial role of ischemia-reperfusion injury on the occurrence and dynamics of microvascular obstruction. The described porcine model using intracoronary injection of thioflavin-S permits accurate characterization of microvascular obstruction after myocardial infarction (AU)

Análisis morfométrico y contenido de ADN en el nevo displásico. Estudio comparativo frente a otras lesiones melanocíticas benignas / Morphometric analysis and DNA content in dysplastic nevi. Comparative study with other benign melanocytic lesions

Introducción. En 1978 se describió el nevo displásico como lesión con aumento del riesgo de melanoma, pero el significado del nevo displásico como precursor de melanoma es controvertido. Numerosos investigadores han intentado correlacionar la presencia de nevo displásico con un tipo específico de fenotipo y genotipo que incluyera la presencia de contenido anormal de ADN. Objetivo. Comparar el contenido de ADN y la morfometría nuclear del nevo displásico con el de lesiones melanocíticas benignas. Mediante una técnica de análisis de imagen se buscó medir de una manera objetiva (cuantitativa) las atipias citológicas que se observan de manera subjetiva en el estudio histológico del nevo displásico. Material y métodos. Se determinó el área nuclear, el factor de forma y el contenido de ADN de 52 lesiones melanocíticas: 8 nevos de unión, 10 nevos compuestos, 10 nevos intradérmicos, 21 nevos displásicos y 3 casos de melanoma como control. Los estudios morfométricos y citométricos se llevaron a cabo mediante un sistema de análisis de imagen CUE-2 (Olympus).Resultados. Todos los casos fueron diploides, con la excepción de 2 nevos displásicos, 2 nevos intradérmicos y 3 melanomas. El factor de forma nuclear fue el mejor para diferenciar el nevo displásico del resto de lesiones melanocíticas benignas, de manera estadísticamente significativa. No se encontraron diferencias morfométricas entre los nevos displásicos familiares y/o múltiples y los esporádicos. Conclusión. Los cambios citológicos nucleares observados en los nevos displásicos con la morfometría se superponen, en general, a los apreciados en las restantes lesiones melanocíticas benignas estudiadas, excepto el factor de forma nuclear, que en los nevos displásicos es más irregular (AU)