Browsing by Author "Del Valle, Felipe"

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    Ecm29-Dependent Proteasome Localization Regulates Cytoskeleton Remodeling at the Immune Synapse
    (2021) Ibanez-Vega, Jorge; Del Valle, Felipe; Saez, Juan Jose; Guzman, Fanny; Diaz, Jheimmy; Soza, Andrea; Yuseff, Maria Isabel
    The formation of an immune synapse (IS) enables B cells to capture membrane-tethered antigens, where cortical actin cytoskeleton remodeling regulates cell spreading and depletion of F-actin at the centrosome promotes the recruitment of lysosomes to facilitate antigen extraction. How B cells regulate both pools of actin, remains poorly understood. We report here that decreased F-actin at the centrosome and IS relies on the distribution of the proteasome, regulated by Ecm29. Silencing Ecm29 decreases the proteasome pool associated to the centrosome of B cells and shifts its accumulation to the cell cortex and IS. Accordingly, Ecm29-silenced B cells display increased F-actin at the centrosome, impaired centrosome and lysosome repositioning to the IS and defective antigen extraction and presentation. Ecm29-silenced B cells, which accumulate higher levels of proteasome at the cell cortex, display decreased actin retrograde flow in lamellipodia and enhanced spreading responses. Our findings support a model where B the asymmetric distribution of the proteasome, mediated by Ecm29, coordinates actin dynamics at the centrosome and the IS, promoting lysosome recruitment and cell spreading.
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    Radiological differential diagnosis and management of retroperitoneal hematomas posterior to radical inguinal orchiectomies. A case report
    (2022) Escobar-Urrejola, Santiago; Astroza, Gaston; Del Valle, Felipe; Fuentes, Alberto; Zuniga, Alvaro
    Introduction: Retroperitoneal hematomas are rare complications of radical inguinal orchiectomy. This case report discusses their radiological differential diagnosis and management.Case presentation: A radical inguinal orchiectomy was performed on a 27-year-old patient. After discharge, he referred back pain. Computed tomography showed a retroperitoneal hematoma. A conservative approach was decided.Discussion: Traditionally, retroperitoneal hematomas have been considered possible radiologic pitfalls, which has therapeutical implications. This pitfall seems less likely in contemporary clinical practice. A conservative approach is preferred in stable patients, whereas active management should be offered to unstable patients. Conclusion: Future studies are necessary to offer evidence-based therapeutical options.