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Showing results for tags 'autophagy'.
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In her latest video/podcast Rhonda Patrick interviews Dr Guido Kroemer on one of her pet topucs: autophagy. I've been listenig to the podcast while driving today, it's a really information-dense. Types of signalling, reltionship with mTOR, IGF-1, prolonged fasting and intermittent fasting. The CR society is mentioned and one of the studies on some practitioners (members of this forum?). The study has not been specified.
All, Over on this thread, Cloud did a helpful translation of a talk (in Italian) by everyone's favorite CR researcher, Luigi Fontana. In his talk, Luigi mentions a new paper  he and colleagues published this month in the open access journal Cell Reports (full text). It looks at several important biomarkers in some of us from the CR Society (mean BMI 19.2), as compared with endurance athletes (mean BMI 22.4) and normal weight controls (mean BMI 25.2). The CR group has significantly higher cortisol (15.6 ng/dl) than either the athletes (11.2) or the controls (12.3). The authors suggest this could be a good thing, since it may reduce systemic inflammation, and is consistent with elevated corticosteroids in CRed rodents. They didn't report any comparison of inflammation markers directly, but did show that one marker of inflammation, tumor necrosis factor alpha (TNF-a), was inversely correlated with cortisol levels across all subjects. This suggest to me that the change in TNF-a (or other markers of inflammation) probably wasn't significantly different across groups, or they would have reported it directly. Unfortunately, the rest of the paper only compares the CR group with the controls - they apparently didn't perform muscle biopsies on the athletes. Compared with controls, the CR folks had higher levels of stress-related biomarkers, like several heat shock proteins (HSPs), and markers of upregulated autophagy, "involved in cellular protein quality control and removal of dysfunctional proteins and organelles." Here is their conclusion: These CR-induced hormetic responses may play a key role in preserving protein quality control, preventing age-associated proteotoxicity, and increasing the capacity for degrading dysfunctional proteins and organelles, thereby preserving cell functionality and the capacity to adjust to a changing environment. These vital housekeeping homeostatic processes have been shown to protect against age-associated disease and may be involved in slowing the rate of aging in humans. Luigi & co. seem to be big into the health/longevity benefits of hormesis lately, including CR, intermittent fasting, exercise, and keeping abdominal fat low. See this thread for more on Luigi's current perspective, from Cloud's translated highlights from Luigi's recent talk. --Dean -------------  Cell Reports 14, 1–7 January 26, 2016 http://dx.doi.org/10.1016/j.celrep.2015.12.042 Long-Term Calorie Restriction Enhances Cellular Quality-Control Processes in Human Skeletal Muscle Ling Yang,1,11 Danilo Licastro,2,11 Edda Cava,3,4,11 Nicola Veronese,3,5 Francesco Spelta,3,6 Wanda Rizza,3,7 Beatrice Bertozzi,3 Dennis T. Villareal,3,8 Go¨ khan S. Hotamisligil,1 John O. Holloszy,3 and Luigi Fontana Full text: http://www.cell.com/cell-reports/pdf/S2211-1247(15)01483-7.pdf SUMMARY Calorie restriction (CR) retards aging, acts as a hormetic intervention, and increases serum corticosterone and HSP70 expression in rodents. However, less is known regarding the effects of CR on these factors in humans. Serum cortisol and molecular chaperones and autophagic proteins were measured in the skeletal muscle of subjects on CR diets for 3–15 years and in control volunteers. Serum cortisol was higher in the CR group than in age-matched sedentary and endurance athlete groups (15.6 ± 4.6 ng/dl versus 12.3 ± 3.9 ng/dl and 11.2 ± 2.7 ng/dl, respectively; p % 0.001). HSP70, Grp78, beclin-1, and LC3 mRNA and/or protein levels were higher in the skeletal muscle of the CR group compared to controls. Our data indicate that CR in humans is associated with sustained rises in serum cortisol, reduced inflammation, and increases in key molecular chaperones and autophagic mediators involved in cellular protein quality control and removal of dysfunctional proteins and organelles.