Atlas interactivo para el estudio morfológico del desarrollo del embrión humano: desarrollo del sistema nervioso y aparato digestivo

Memoria ID2022-137 Ayudas de la Universidad de Salamanca para la innovación docente, curso 2022-2023

Relation among Aromatase P450 and Tumoral Growth in Human Prolactinomas

[EN]The pituitary gland is part of hypothalamic-pituitary–gonadal axis, which controls development, reproduction, and aging in humans and animals. In addition, the pituitary gland is regulated mainly by hormones and neurotransmitters released from the hypothalamus and by systemic hormones secreted by target glands. Aromatase P450, the enzyme responsible for the catabolization of aromatizable androgens to estrogens, is expressed in different parts of body, including the pituitary gland. Moreover, aromatase P450 is involved in sexual dimorphism where alteration in the level of aromatase can initiate a number of diseases in both genders. On the other hand, the direct actions of estrogens, mainly estradiol, are well known for stimulating prolactin release. Numerous studies have shown that changes in the levels of estrogens, among other factors, have been implicated in the genesis and development of prolactinoma. The pituitary gland can produce estradiol locally in several types of endocrine cells, and it is possible that aromatase could be responsible for the maintenance of the population of lactotroph cells and the modulation of the action of central or peripheral regulators. Aromatase overexpression due to inappropriate gene regulation has clinical effects such as the pathogenesis of prolactinomas. The present study reports on the synthesis of pituitary aromatase, its regulation by gonadal steroids, and the physiological roles of aromatase on pituitary endocrine cells. The involvement of aromatase in the pathogenesis of pituitary tumors, mainly prolactinomas, through the auto-paracrine production of estradiol is reviewed

Desarrollo en Flash de un simulador para el estudio-aprendizaje individualizado en las clases prácticas de la Anatomía Clínica del Tórax

Memoria ID-102. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2019-2020.[Es] Este proyecto tiene como objetivo el desarrollo de una aplicación en flash que permita al estudiante seguir un proceso de aprendizaje durante las prácticas de Anatomía del Tóra

Evidences for Expression and Location of ANGPTL8 in Human Adipose Tissue

The metabolism of triglycerides (TGs) is regulated, among others, by the lipoprotein lipase (LPL) that hydrolyses the TGs on endothelial cells. In turn, LPL is inhibited by the ANGPTLs family of proteins, such as ANGPTL3, 4, and, 8; the latter is the least known. In this work, we have tried to establish the expression and localisation of the Angiopoietin-like 8 (ANGPTL8) protein in the visceral adipose tissue (VAT) of morbid-obese and non-obese patients. 109 subjects (66 women and 43 men) undergoing laparoscopic surgery participated in this study. A blood sample and a portion of the VAT were obtained, and the patients were classified according to their Body Mass Index (BMI) as non-obese (19.5–30 kg/m2) and morbid-obese (40–50 kg/m2). No significant changes in ANGPTL8 plasma levels were determined by EIA in obese patients. The immunocytochemistry and Western blotting showed the presence of increased ANGPTL8 in morbid-obese patients (p < 0.05). In-situ hybridisation and a real time polymerase chain reaction (RT-PCR) confirmed that the mRNA that encodes ANGPTL8 was present in adipocytes, without differences in their nutritional state (p = 0.89), and even in the endothelial cells. Our data suggests that ANGPT8 plasmatic levels do not change significantly in patients with morbid obesity, although there is a modest difference related to gender. Besides, we demonstrate that in visceral adipose tissue, ANGPTL8 is well defined in the cytoplasm of adipocytes coexisting with perilipin-1 and its mRNA, also is present in endothelial cells. These findings suggest the possibility that among other functions, ANGPTL8 could perform either a paracrine and/or an endocrine role in the adipose tissue

Análisis de la expresión de ANGPTL8 en tejido adiposo humano y su posible implicación en obesidad

[ES]Introducción: El tejido adiposo está implicado en patologías como obesidad y diabetes. A parte de su papel en el almacenamiento energético, es considerado como un órgano endocrino capaz de sintetizar y liberar adipoquinas. Una de ellas, ANGPTL8, ha sido identificada como una de las responsables de la inhibición de LPL. Además de las discrepancias a la hora de determinar su concentración plasmática en individuos no obesos ni diabéticos, no se ha llegado a un conceso de las modificaciones que provocan estas patologías. Es necesario un estudio más profundo de su papel en el control del perfil lipídico en obesos. Materiales y métodos: Analizamos la presencia de ANGPTL8 en plasma y tejido adiposo visceral humano procedente de 63 pacientes del Hospital Universitario de Salamanca, mediante EIA, Western blot, inmunohistoquímica e hibridación in-situ, así como también estudios funcionales de lipólisis y cultivo de explantes de tejido adiposo de estos pacientes. Resultados: La concentración plasmática de ANGPTL8 se redujo en obesos, y sólo se correlacionó positivamente con HDL. En obesos ANGPTL8 aumentó, mientras que la expresión de su mensajero sólo aumentó en mujeres obesas. ANGPTL8 no estuvo presente en las células endoteliales del tejido adiposo, así como tampoco su mensajero. La incubación con ANGPTL8 produjo un descenso del glicerol liberado en todos los grupos, a excepción de la incubación junto a insulina, que provocó un aumento de la lipólisis. La incubación de los explantes de mujeres obesas con metformina produjo un aumento dosis-dependiente de la expresión relativa de ANGPTL8. Conclusiones: ANGPTL8 tiende a reducirse en el plasma a medida que se deteriora el perfil lipídico y glucídico. La expresión de ANGPTL8 se ve modificada en estados de obesidad, influenciada por el sexo y la sensibilidad insulínica. El efecto de ANGPTL8 sobre la actividad lipolítica depende posiblemente de su concentración

Endothelial immunocytochemical expression of pituitary IL-1β and its relation to ACTH-positive cells is regulated by corticosterone in the male rat

[EN] Interleukin-1 beta (IL-1β) is a cytokine linking the neuroendocrine system and metabolic homeostasis. We have previously demonstrated the relevance of IL-1β for maintaining the pituitary ACTH-producing cells by immuno-blocking its effects in pituitary cultures. However, the morphological characteristics and the intimate relationship of the pituitary cells expressing IL-1β and ACTH remain unknown. For determining pituitary variations of immunoreactivity for IL-1β and its relation with ACTH-positive cells under stress situations, we performed an immunohistochemical analysis of the expression of IL-1β and ACTH in the pituitary gland of adult rats, in the absence or presence of corticosterone, by establishing different groups: untreated, sham-operated, and bilaterally adrenalectomized animals. In the rats subjected to surgery, the glucocorticoid was administered on the same day of the intervention and on the third day post-surgery. Interestingly, it was observed that IL-1β was located in the pituitary endothelial cells at the hypophyseal portal vessels, regardless of the treatment schedule

Dopamine Modulates Insulin Release and Is Involved in the Survival of Rat Pancreatic Beta Cells

<div><p>The local synthesis of dopamine and its effects on insulin release have been described in isolated islets. Thus, it may be accepted that dopamine exerts an auto-paracrine regulation of insulin secretion from pancreatic beta cells. The aim of the present study is to analyze whether dopamine is a regulator of the proliferation and apoptosis of rat pancreatic beta cells after glucose-stimulated insulin secretion. Glucose stimulated pancreatic islets obtained from male Wistar rats were cultured with 1 or 10 μM dopamine from 1 to 12 h. Insulin secretion was analyzed by RIA. The cellular proliferation rate of pancreatic islets and beta cells was studied with immunocytochemical double labelling for both insulin and PCNA (proliferating cell nuclear antigen), and active caspase-3 was detected to evaluate apoptosis. The secretion of insulin from isolated islets was significantly inhibited (p<0.01), by treatment with 1 and 10 μM dopamine, with no differences between either dose as early as 1 h after treatment. The percentage of insulin-positive cells in the islets decreased significantly (p<0.01) after 1 h of treatment up to 12 h. The proliferation rate of insulin-positive cells in the islets decreased significantly (p<0.01) following treatment with dopamine. Apoptosis in pancreatic islets and beta cells was increased by treatment with 1 and 10 μM dopamine along 12 h. In conclusion, these results suggest that dopamine could modulate the proliferation and apoptosis of pancreatic beta cells and that dopamine may be involved in the maintenance of pancreatic islets.</p></div

Morphometric effect induced by treatment with dopamine on cellular (A) and nuclear (B) area of beta cells.

<p>Histological sections were selected from micrographs of cross sections of each islets (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0123197#sec002" target="_blank">methods</a>). In each section the cellular and the nuclear cell profiles from insulin-positive cells were plotted, allowing the surface of the cell and nuclear areas to be calculated after calibration of the Image J application. Cellular and nuclear area from10 islets per study group, and 100cells per islet were measured in 10 mM glucose, 1μM and 10 μM dopamine. (area: μm², **p<0.01).</p

Inmunocytochemical analysis of insulin-positive cells in isolated islets treated with dopamine.

<p><b>(A)</b> Micrographs showing some immunocytochemical staining patterns for insulin (red) in control islets (i), and dopamine-treated islets at 1, 3, 6 and 12 h (ii). <b>(B)</b> Plot showing the decrease induced by dopamine in the percentage of insulin-positive cells at the different time-points assayed; from 1 to 12 hours of treatment a significant decrease (*p<0.05, **p<0.01 with respect to their respective controls) was observed. Scale bar: 50 μm.</p