Browsing by Author "Paredes, Felipe"

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    From Unsustainability to MSC Certification: A Case Study of the Artisanal Chilean South Pacific Hake Fishery
    (2016) Plotnek, Emma; Paredes, Felipe; Galvez, Mauricio; Perez-Ramirez, Monica
    The Marine Stewardship Council (MSC) certification is a market-based incentive program that recognizes sustainable fisheries through a third-party assessment. This study considers a potential project to MSC-certify the small-scale sector of the South Pacific hake (Merluccius gayi gayi) fishery in Chile. Using semi-structured interviews with fishery stakeholders and bibliographic review, the study surveys the technical, stakeholder, and market barriers to certification. Barriers included an over-exploited stock, lack of information about the ecosystem, and the currently-evolving management system. In addition, noncompliance of existing norms and social arrangements within the fishery are leading to a situation where illegal fishing occurs. Even though MSC certification is positively perceived by most stakeholders, it is considered to be neither achievable by the status of the fishery nor desirable, since it cannot offer economic benefits due to the domestic market features. At present, the most constructive actions for the fishery would be to implement strong management and effective enforcement, and break-down the currently unregulated market structure, as well as empower the fishermen. Long-term efforts in these areas may be executed using the MSC Standard as a diagnostic tool to identify the improvements required to move the fishery toward better performance.
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    HERPUD1 governs tumor cell mitochondrial function via inositol 1,4,5-trisphosphate receptor-mediated calcium signaling
    (2024) Paredes, Felipe; Navarro-Marquez, Mario; Quiroga, Clara; Jimenez-Gallegos, Danica; Yeligar, Samantha M.; Parra, Valentina; Mueller, Marioly; Chiong, Mario; Quest, Andrew F. G.; San Martin, Alejandra; Lavandero, Sergio
    The intricate relationship between calcium (Ca2+) homeostasis and mitochondrial function is crucial for cellular metabolic adaptation in tumor cells. Ca2+-initiated signaling maintains mitochondrial respiratory capacity and ATP synthesis, influencing critical cellular processes in cancer development. Previous studies by our group have shown that the homocysteine-inducible ER Protein with Ubiquitin-Like Domain 1 (HERPUD1) regulates inositol 1,4,5-trisphosphate receptor (ITPR3) levels and intracellular Ca2+ signals in tumor cells. This study explores the role of HERPUD1 in regulating mitochondrial function and tumor cell migration by controlling ITPR3-dependent Ca2+ signals.We found HERPUD1 levels correlated with mitochondrial function in tumor cells, with HERPUD1 deficiency leading to enhanced mitochondrial activity. HERPUD1 knockdown increased intracellular Ca2+ release and mitochondrial Ca2+ influx, which was prevented using the ITPR3 antagonist xestospongin C or the Ca2+ chelator BAPTA-AM. Furthermore, HERPUD1 expression reduced tumor cell migration by controlling ITPR3-mediated Ca2+ signals. HERPUD1-deficient cells exhibited increased migratory capacity, which was attenuated by treatment with xestospongin C or BAPTA-AM. Additionally, HERPUD1 deficiency led to reactive oxygen species -dependent activation of paxillin and FAK proteins, which are associated with enhanced cell migration.Our findings highlight the pivotal role of HERPUD1 in regulating mitochondrial function and cell migration by controlling intracellular Ca2+ signals mediated by ITPR3. Understanding the interplay between HERPUD1 and mitochondrial Ca2+ regulation provides insights into potential therapeutic targets for cancer treatment and other pathologies involving altered energy metabolism.