Browsing by Author "Riquelme Illanes, Cecilia Angélica"

Now showing 1 - 14 of 14
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    ACE2 is augmented in dystrophic skeletal muscle and plays a role in decreasing associated fibrosis
    (2014) Riquelme Illanes, Cecilia Angélica; Acuna, M.; Torrejon, J.; Rebolledo, D.; Cabrera, D.; Santos, R.; Brandan, Enrique
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    Antisense Inhibition of Decorin Expression in Myoblasts Decreases Cell Responsiveness to Transforming Growth Factor B and Accelerates Skeletal Muscle Defferentiation
    (Elsevier Inc, 2001) Riquelme Illanes, Cecilia Angélica; Larraín Correa, Juan Agustín; Schönherr, Elke; Henríquez, Juan Pablo; Kresse, Hans; Brandan, Enrique
    Decorin is a member of the family of the small leucine-rich proteoglycans. In addition to its function as an extracellular matrix organizer, it has the ability to activate the epidermal growth factor receptor, and it forms complexes with various isoforms of transforming growth factor beta (TGF-beta), Decorin is expressed during skeletal muscle differentiation and is up-regulated in dystrophic muscle. In this study we investigated the role of decorin in TGF-beta -dependent inhibition of myogenesis, To probe the function of decorin during myogenesis, C2C12 myoblasts were stably transfected with a plasmid expressing antisense decorin mRNA. The re; suiting inhibition of decorin expression led to the expression of myogenin, a master transcription factor for muscle differentiation, under growth conditions and accelerated skeletal muscle differentiation as determined by the expression of creatine kinase, In contrast myogenin expression was inhibited by adenovirally induced decorin expression or by adding exogenous decorin, Reduced synthesis of decorin resulted in a 7-fold decreased sensitivity to TGF-beta -mediated inhibition of myogenin expression. In contrast, adenovirally induced decorin expression in wild type cells resulted in a 5-fold increased sensitivity to TGF-beta -mediated inhibition of myogenin expression. Transfection studies with the TGF-beta -dependent promoter of the plasminogen activator inhibitor-1 coupled with luciferase revealed that the transducing receptors for TGF-beta1 and TGF-beta2 were involved in the different responses of wild type and anti-sense decorin myoblasts, These results demonstrate that a reduction of decorin expression or of decorin availability results in a decreased responsiveness to TGF-beta. These findings strongly suggest a new role for decorin during skeletal muscle terminal differentiation by activating TGF-beta -dependent signaling pathways.
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    Betaglycan expression is transcriptionally up-regulated during skeletal muscle differentiation: Cloning of murine betaglycan gene promoter and its modulation by myoD, retinoic acid, and transforming growth factor-beta
    (Elsevier Inc., 2003) López-Casillas, Fernando; Riquelme Illanes, Cecilia Angélica; Pérez-Kato, Yoshiaki; Ponce-Castañeda, M. Verónica; Osses Rivera, Nelson Eduardo; Esparza-López, José; González-Núñez, Gerardo; Cabello Verrugio, Claudio Alejandro; Mendoza, Valentín; Troncoso, Víctor; Brandan, Enrique
    Betaglycan is a membrane-anchored proteoglycan co-receptor that binds transforming growth factor beta (TGF-beta) via its core protein and basic fibroblast growth factor through its glycosaminoglycan chains. In this study we evaluated the expression of betaglycan during the C2C12 skeletal muscle differentiation. Betaglycan expression, as determined by Northern and Western blot, was up-regulated during the conversion of myoblasts to myotubes. The mouse betaglycan gene promoter was cloned, and its sequence showed putative binding sites for SP1, Smad3, Smad4, muscle regulatory factor elements such as MyoD and MEF2, and retinoic acid receptor. Transcriptional activity of the mouse betaglycan promoter reporter was also up-regulated in differentiating C2C12 cells. We found that MyoD, but not myogenin, stimulated this transcriptional activity even in the presence of high serum. Betaglycan promoter activity was increased by RA and inhibited by the three isoforms of TGF-beta. On the other hand, basic fibroblast growth factor, BMP-2, and hepatocyte growth factor/scatter factor, which are inhibitors of myogenesis, had little effect. In myotubes, up-regulated betaglycan was also detectable by TGF-beta affinity labeling and immunofluorescence microscopy studies. The latter indicated that betaglycan was localized both on the cell surface and in the ECM Forced expression of betaglycan in C2C12 myoblasts increases their responsiveness to TGF-beta2, suggesting that it performs a TGF-beta presentation function in this cell lineage. These results indicate that betaglycan expression is up-regulated during myogenesis and that MyoD and RA modulate its expression by a mechanism that is independent of myogenin.
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    Burmese pythons exhibit a transient adaptation to nutrient overload that prevents liver damage
    (2022) Magida, Jason A.; Tan, Yuxiao; Wall, Christopher E.; Harrison, Brooke C.; Marr, Thomas G.; Peter, Angela K.; Riquelme Illanes, Cecilia Angélica; Leinwand, Leslie A.
    As an opportunistic predator, the Burmese python (Python molurus bivittatus) consumes large and infrequent meals, fasting for up to a year. Upon consuming a large meal, the Burmese python exhibits extreme metabolic responses. To define the pathways that regulate these postprandial metabolic responses, we performed a comprehensive profile of plasma metabolites throughout the digestive process. Following ingestion of a meal equivalent to 25% of its body mass, plasma lipoproteins and metabolites, such as chylomicra and bile acids, reach levels observed only in mammalian models of extreme dyslipidemia. Here, we provide evidence for an adaptive response to postprandial nutrient overload by the python liver, a critical site of metabolic homeostasis. The python liver undergoes a substantial increase in mass through proliferative processes, exhibits hepatic steatosis, hyperlipidemia-induced insulin resistance indicated by PEPCK activation and pAKT deactivation, and de novo fatty acid synthesis via FASN activation. This postprandial state is completely reversible. We posit that Burmese pythons evade the permanent hepatic damage associated with these metabolic states in mammals using evolved protective measures to inactivate these pathways. These include a transient activation of hepatic nuclear receptors induced by fatty acids and bile acids, including PPAR and FXR, respectively. The stress-induced p38 MAPK pathway is also transiently activated during the early stages of digestion. Taken together, these data identify a reversible metabolic response to hyperlipidemia by the python liver, only achieved in mammals by pharmacologic intervention. The factors involved in these processes may be relevant to or leveraged for remediating human hepatic pathology.
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    Extracellular Proteoglycans Modify Tgf-Beta Bio-Availability Attenuating Its Signaling During Skeletal Muscle Differentiation
    (Elsevier, 2006) Droguett Mallea, Rebeca Antonia; Cabello Verrugio, Claudio Alejandro; Riquelme Illanes, Cecilia Angélica; Brandan, Enrique
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    Fatty Acids Identified in the Burmese Python Promote Beneficial Cardiac Growth
    (2011) Riquelme Illanes, Cecilia Angélica
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    Novel and optimized strategies for inducing fibrosis in vivo: Focus on Duchenne Muscular Dystrophy
    (2014) Pessina, P.; Cabrera García, Daniel Alejandro; Morales France, María Gabriela; Riquelme Illanes, Cecilia Angélica
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    Palmitic Acid Reduces the Autophagic Flux and Insulin Sensitivity Through the Activation of the Free Fatty Acid Receptor 1 (FFAR1) in the Hypothalamic Neuronal Cell Line N43/5
    (2019) Hernández Cáceres, María Paz; Toledo Valenzuela, Lilian Alejandra; Diaz-Castro, F.; Avalos, Y.; Burgos, P.; Narro, C.; Morselli, Eugenia; Espinoza Caicedo, Jasson Amadeus; Cifuentes Araneda, Flavia Dominique; Riquelme Illanes, Cecilia Angélica; Navarro-Aguad, F.; Troncoso, R.; Criollo, A.; Pena-Oyarzun, D.
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    Structure of p300 bound to MEF2 on DNA reveals a mechanism of enhanceosome assembly
    (2011) He, J.; Riquelme Illanes, Cecilia Angélica
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    SUMO-1 modification of MEF2A regulates its transcriptional activity
    (2006) Riquelme Illanes, Cecilia Angélica
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    Transforming growth factor type beta 1 increases the expression of angiotensin II receptor type 2 by a SMAD- and p38 MAPK-dependent mechanism in skeletal muscle
    (2013) Painemal, P.; Acuña Díaz-Tendero, María José; Riquelme Illanes, Cecilia Angélica; Brandan, Enrique
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    Transforming growth factor type-b inhibits Masreceptor expression in fibroblasts but not inmyoblasts or differentiated myotubes; Relevanceto fibrosis associated to muscular dystrophies
    (2015) Cofré, Catalina; Acuña, María José; Contreras, Osvaldo; Morales, María Gabriela; Riquelme Illanes, Cecilia Angélica; Cabello Verrugio, Claudio Alejandro; Brandan, Enrique; Cofré, Catalina; Acuña, María José; Contreras Saavedra, Osvaldo Isaías; Morales, María Gabriela; Riquelme Illanes, Cecilia Angélica; Cabello Verrugio, Claudio Alejandro; Brandan, Enrique
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    Ubc9 expression is essential for myotube formation in C2C12
    (2006) Riquelme Illanes, Cecilia Angélica
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