Browsing by Subject "Adipose tissue"

Now showing 1 - 4 of 4
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    Diet: a specific part of the western lifestyle pack in the asthma epidemic
    (MDPI, 2020-07-01) Frontela Saseta, María del Carmen; González-Bermúdez, Carlos A.; García-Marcos Álvarez, Luis Vicente; Tecnología de Alimentos, Nutrición y Bromatología
    The Western lifestyle is a complex concept that includes the diet as the main axis of di erent factors which contribute to a detrimental e ect on health, lower life expectancy and low quality-of-life. This type of diet is characterized by being high in calories, mainly provided by saturated fats, and rich in sugars that can lead to changes in immune cells and their responsiveness, by di erent mechanisms that have yet to be totally clarified. Inflammatory processes are perpetuated through di erent pathways, in which adipose tissue is a major factor. High fat stores in overweight and obesity accumulate energy but the endocrine function is also producing and releasing diferent bioactive compounds, adipokines, known to be pro-inflammatory and which play an important role in the pathogenesis of asthma. This review therefore explores the latest evidence regarding the adverse e ect of theWestern diet on adipose tissue inflammation and its causative e ect on the asthma epidemic.
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    Histology of skeletal muscle reconstructed by means of the implantation of autologous adipose tissue: an experimental study
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Leiva Cepas, Fernando; Jimena, Ignacio; Ruz Caracuel, Ignacio; Luque, Evelio; Villalba, Rafael; Peña Amaro, Jose
    The purpose of this study was to determine the histological characteristics of a skeletal muscle reconstructed by means of the implantation of autologous adipose tissue following an experimentally- induced volumetric muscle loss. A cylindrical piece in the belly of the rat anterior tibial muscle was removed. In the hole, inguinal subcutaneous adipose tissue of the same rat was grafted. Animals were sacrificed 7, 14, 21, 28 and 60 days posttransplantation. Histological, histochemical, immunohistochemical and morphometric techniques were used. At all times analyzed, the regenerative muscle fibers formed from the edges of the muscle tissue showed histological, histochemical and immunohistochemical differences in comparison with the control group. These differences are related to delays in the maturation process and are related to problems in reinnervation and disorientation of muscle fibers. The stains for MyoD and desmin showed that some myoblasts and myotubes seem to derive from the transplanted adipose tissue. After 60 days, the transplant area was 20% occupied by fibrosis and by 80% skeletal muscle. However, the neo-muscle was chaotically organized showing muscle fiber disorientation and centronucleated fibers with irregular shape and size. Our results support the hypothesis that, at least from a morphological point of view, autologous adipose tissue transplantation favors reconstruction following a volumetric loss of skeletal muscle by combining the inherent regenerative response of the organ itself and the myogenic differentiation of the stem cells present in the adipose tissue. However, in our study, the formed neo- muscle exhibited histological differences in comparison with the normal skeletal muscle
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    Melatonin decreases human adipose tissue insulin sensitivity
    (Wiley, 2024-06) Zambrano, Carolina; Tena Garitaonaindia, Mireia; Salmerón, Diego; Pérez‐Sanz, Fernando; Tchio, Cynthia; Picinato, María Cecilia; Sánchez de Medina, Fermín; Luján, Juan; Scheer, Frank A. J. L.; Saxena, Richa; Martínez‐Augustin, Olga; Garaulet, Marta; Ciencias Sociosanitarias
    Melatonin is a pineal hormone that modulates the circadian system and exerts soporific and phase‐shifting effects. It is also involved in many other physiological processes, such as those implicated in cardiovascular, endocrine, immune, and metabolic functions. However, the role of melatonin in glucose metabolism remains contradictory, and its action on human adipose tissue (AT) explants has not been demonstrated. We aimed to assess whether melatonin (a pharmacological dose) influences insulin sensitivity in human AT. This will help better understand melatonin administration's effect on glucose metabolism. Abdominal AT (subcutaneous and visceral) biopsies were obtained from 19 participants with severe obesity (age: 42.84 ± 12.48 years; body mass index: 43.14 ± 8.26 kg/m2 ) who underwent a laparoscopic gastric bypass. AT biopsies were exposed to four different treatments: control (C), insulin alone (I) (10 nM), melatonin alone (M) (5000 pg/mL), and insulin plus melatonin combined (I + M). All four conditions were repeated in both subcutaneous and visceral AT, and all were performed in the morning at 8 a.m. (n = 19) and the evening at 8 p.m. (in a subsample of n = 12). We used western blot analysis to determine insulin signaling (using the pAKT/ tAKT ratio). Furthermore, RNAseq analyses were performed to better understand the metabolic pathways involved in the effect of melatonin on insulin signaling. As expected, insulin treatment (I) increased the pAKT/ tAKT ratio compared with control (p < .0001). Furthermore, the addition of melatonin (I + M) resulted in a decrease in insulin signaling as compared with insulin alone (I); this effect was significant only during the evening time (not in the morning time). Further, RNAseq analyses in visceral AT during the evening condition (at 8 p.m.) showed that melatonin resulted in a prompt transcriptome response (around 1 h after melatonin addition), particularly by downregulating the insulin signaling pathway. Our results show that melatonin reduces insulin sensitivity in human AT during the evening. These results may partly explain the previous studies showing a decrease in glucose tolerance after oral melatonin administration in the evening or when eating late when endogenous melatonin is present.
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    Role of extracellular matrix remodelling in adipose tissue pathophysiology. Relevance in the development of obesity
    (F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Catalán, Victoria; Gómez-Ambrosi, Javier; Rodríguez, Amaia; Frühbeck, Gema
    Adipose tissue responds dynamically to alterations in nutrient excess through adipocyte hypertrophy and hyperplasia, followed by increased angiogenesis, immune cell infiltration, extracellular matrix (ECM) overproduction, and thus, increased production of proinflammatory adipokines during the progression of chronic inflammation. Adipose tissue remodelling is an ongoing process that is pathologically accelerated in the obese state in large part mediated by ECM proteins and proteases. The ECM is subject to major modifications by adipocytes and other cell types that are infiltrated in the adipose tissue, such as macrophages and vascular cells. In obesity, unusual expression of ECM components and fragments derived from tissue-remodelling processes can influence immune cell recruitment and activation, actively contributing to inflammation. ECM turnover requires a tightly regulated balance between the synthesis of the components and their proteolysis, mainly by fibrinolytic systems and matrix metalloproteases (MMPs). In this review, we discuss the key cellular steps that lead to adipose tissue remodelling and the main molecular mechanisms and mediators in this process. We highlight the importance of hypoxia and angiogenesis in the adipose remodelling process, as well as the cross-talk between adipocytes, macrophages and ECM components