Browsing by Author "Vilos, Cristian"

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    Active acetylcholine receptors prevent the atrophy of skeletal muscles and favor reinnervation
    (2020) Cisterna, Bruno A.; Vargas, Anibal A.; Puebla, Carlos; Fernandez, Paola; Escamilla, Rosalba; Lagos, Carlos F.; Matus, Maria F.; Vilos, Cristian; Cea, Luis A.; Barnafi, Esteban; Gaete, Hugo; Escobar, Daniel F.; Cardozo, Christopher P.; Saez, Juan C.
    Denervation of skeletal muscles induces severe muscle atrophy, which is preceded by cellular alterations such as increased plasma membrane permeability, reduced resting membrane potential and accelerated protein catabolism. The factors that induce these changes remain unknown. Conversely, functional recovery following denervation depends on successful reinnervation. Here, we show that activation of nicotinic acetylcholine receptors (nAChRs) by quantal release of acetylcholine (ACh) from motoneurons is sufficient to prevent changes induced by denervation. Using in vitro assays, ACh and non-hydrolysable ACh analogs repressed the expression of connexin43 and connexin45 hemichannels, which promote muscle atrophy. In co-culture studies, connexin43/45 hemichannel knockout or knockdown increased innervation of muscle fibers by dorsal root ganglion neurons. Our results show that ACh released by motoneurons exerts a hitherto unknown function independent of myofiber contraction. nAChRs and connexin hemichannels are potential molecular targets for therapeutic intervention in a variety of pathological conditions with reduced synaptic neuromuscular transmission.
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    Combined Administration of Andrographolide and Angiotensin- (1-7) Synergically Increases the Muscle Function and Strength in Aged Mice
    (2022) Abrigo, Johanna; Simon, Felipe; Cabrera, Daniel; Vilos, Cristian; Cabello-Verrugio, Claudio
    Background: Sarcopenia is a progressive and generalized skeletal muscle disorder characterized by muscle weakness, loss of muscle mass, and decline in the capacity of force generation. Aging can cause sarcopenia. Several therapeutic strategies have been evaluated to prevent or alleviate this disorder. One of them is angiotensin 1-7 [Ang-(1-7)], an anti-atrophic peptide for skeletal muscles that regulates decreased muscle mass for several causes, including aging. Another regulator of muscle mass and function is andrographolide, a bicyclic diterpenoid lactone that decreases the nuclear factor kappa B (NF-kappa B) signaling and attenuates the severity of some muscle diseases. Objective: Evaluate the effect of combined administration of Ang-(1-7) with andrographolide on the physical performance, muscle strength, and fiber ' s diameter in a murine model of sarcopenia by aging. Methods: Aged male mice of the C57BL/6J strain were treated with Andrographolide, Ang-(1-7), or combined for three months. The physical performance, muscle strength, and fiber ' s diameter were measured. Results: The results showed that aged mice (24 months old) treated with Ang-(1-7) or Andrographolide improved their performance on a treadmill test, muscle strength, and their fiber ' s diameter compared to aged mice without treatment. The combined administration of Ang-(1-7) with andrographolide to aged mice has an enhanced synergically effect on physical performance, muscle strength, and fiber ' s diameter. Conclusion: Our results indicated that in aged mice, the effects of andrographolide and Ang-(1-7) on muscle function, strength, and fiber ' s diameter are potentiated.
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    TGF-β requires the activation of canonical and non-canonical signalling pathways to induce skeletal muscle atrophy
    (2018) Ábrigo, Johanna; Campos, Fabian; Simon, Felipe; Riedel, Claudia; Cabrera García, Daniel Alejandro; Vilos, Cristian; Cabello Verrugio, Claudio Alejandro
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    The Human Dermis as a Target of Nanoparticles for Treating Skin Conditions
    (2023) Salazar Muñoz, Javier Alonso; Carmona, Thais; Zacconi, Flavia C. M.; Venegas Yazigi, Diego; Cabello Verrugio, Claudio; Il Choi, Won; Vilos, Cristian
    Skin has a preventive role against any damage raised by harmful microorganisms and physical and chemical assaults from the external environment that could affect the body’s internal organs. Dermis represents the main section of the skin, and its contribution to skin physiology is critical due to its diverse cellularity, vasculature, and release of molecular mediators involved in the extracellular matrix maintenance and modulation of the immune response. Skin structure and complexity limit the transport of substances, promoting the study of different types of nanoparticles that penetrate the skin layers under different mechanisms intended for skin illness treatments and dermo-cosmetic applications. In this work, we present a detailed morphological description of the dermis in terms of its structures and resident cells. Furthermore, we analyze the role of the dermis in regulating skin homeostasis and its alterations in pathophysiological conditions, highlighting its potential as a therapeutic target. Additionally, we describe the use of nanoparticles for skin illness treatments focused on dermis release and promote the use of metal-organic frameworks (MOFs) as an integrative strategy for skin treatments.