15 research outputs found

    Depletion of Beclin-1 Due to Proteolytic Cleavage by Caspases in the Alzheimer\u27s Disease Brain

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    The Beclin-1 protein is essential for the initiation of autophagy and recent studies suggest this function may be compromised in Alzheimer’s disease (AD). In addition, in vitro studies have supported a loss of function of Beclin-1 due to proteolytic modification by caspases. In the present study we examined whether caspase-cleavage of Beclin-1 occurs in the AD brain by designing a site-directed caspase-cleavage antibody based upon a known cleavage site within the protein at position D149. We confirmed that Beclin-1 is an excellent substrate for caspase-3 and demonstrate cleavage led to the formation of a 35 kDa C-terminal fragment labeled by our novel antibody following Western blot analysis. Application of this antibody termed Beclin-1 caspase-cleavage product antibody or BeclinCCP in frontal cortex tissue sections revealed strong immunolabeling within astrocytes that localized with plaque-regions and along blood vessels in all AD cases examined. In addition, weaker, more variable BeclinCCP labeling was also observed within neurofibrillary tangles that co-localized with the early tau conformational marker, MC-1 as well as the late tangle marker, PHF-1. Collectively, these data support a depletion of Beclin-1 in AD following caspase-cleavage

    Depletion of Beclin-1 due to proteolytic cleavage by caspases in the Alzheimer's disease brain

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    The Beclin-1 protein is essential for the initiation of autophagy and recent studies suggest this function may be compromised in Alzheimer’s disease (AD). In addition, in vitro studies have supported a loss of function of Beclin-1 due to proteolytic modification by caspases. In the present study we examined whether caspase-cleavage of Beclin-1 occurs in the AD brain by designing a site-directed caspase-cleavage antibody based upon a known cleavage site within the protein at position D149. We confirmed that Beclin-1 is an excellent substrate for caspase-3 and demonstrate cleavage led to the formation of a 35 kDa C-terminal fragment labeled by our novel antibody following Western blot analysis. Application of this antibody termed Beclin-1 caspase-cleavage product antibody or BeclinCCP in frontal cortex tissue sections revealed strong immunolabeling within astrocytes that localized with plaque-regions and along blood vessels in all AD cases examined. In addition, weaker, more variable BeclinCCP labeling was also observed within neurofibrillary tangles that co-localized with the early tau conformational marker, MC-1 as well as the late tangle marker, PHF-1. Collectively, these data support a depletion of Beclin-1 in AD following caspase-cleavage

    Butaro Hospital, a Sustainable Hospital with Participatory Design and Construction Process

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    Healthcare facilities are very important for sustainable rural regions in developing countries. The Republic of Rwanda, in central east Africa, suffered massive social conflict in 1994 between the Hutu and Tutsi. Furthermore the health problem happened in Burera District because of lack of a proper district hospital. Therefore, in January 2011, the Rwandan Ministry of Health and Partners in Health (PIH) opened the 140-bed Butaro Hospital in the Burera District of Rwanda. The paper-based research was conducted based on hospital’s architecture of Hatmoko, et.al. (2010). Analysis was made with based on the secondary data of Butaro Hospital. Lastly, primary data gathering would be conducted if the funding allowed. The Butaro Hospital was an affordable solution for healthcare problems in rural regions of the developing countries, especially the infectious diseases (such as: HIV, malaria, tuberculosis, nose-ear-and-throat disease). Sustainable innovative solutions for minimum infection were implemented such as: external corridors, large-radius-low-speed fans (with diameters of 24 feet), high-louvered windows, germicidal UV lights, and non-permeable-continuous flooring. The construction of the hospital also would reduce the impact of political crisis in 1994. The project created 4,000 jobs for local craftsmen and local residents. They were initially trained for manual excavation, construction, and project management, before involving in the hospital construction. Therefore, the Butaro Hospital supported the smart regions of Burera area. Keywords: Sustainable and affordable hospital, participatory design, local materia

    Caspase-mediated cleavage of Beclin-1 inactivates Beclin-1-induced autophagy and enhances apoptosis by promoting the release of proapoptotic factors from mitochondria

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    Autophagy and apoptosis are two important and interconnected stress-response mechanisms. However, the molecular interplay between these two pathways is not fully understood. To study the fate and function of autophagic proteins at the onset of apoptosis, we used a cellular model system in which autophagy precedes apoptosis. IL-3 depletion of Ba/F3 cells caused caspase (casp)-mediated cleavage of Beclin-1 and PI3KC3, two crucial components of the autophagy-inducing complex. We identified two casp cleavage sites in Beclin-1, TDVD133 and DQLD149, cleavage at which yields fragments lacking the autophagyinducing capacity. Noteworthy, the C-terminal fragment, Beclin-1-C, localized predominantly at the mitochondria and sensitized the cells to apoptosis. Moreover, on isolated mitochondria, recombinant Beclin-1-C was able to induce the release of proapoptotic factors. These findings point to a mechanism by which casp-dependent generation of Beclin-1-C creates an amplifying loop enhancing apoptosis upon growth factor withdrawal
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