Project description:Heart failure with preserved ejection fraction (HFpEF) is characterised by a distinct but poorly understood in skeletal muscle pathology. In a rat model ZSF1, we identify impaired myonuclear accretion as a mechanism for ablated myofiber growth in HFpEF following resistance exercise intervention. Muscle vascular or mitochondrial dysfunction, or impaired protein synthesis signalling, do not appear as primary limiting mechanisms, and cardiac therapies do not attenuate skeletal muscle pathology. However, we identify that acute caloric restriction rejuvenates myofiber growth in HFpEF during resistance exercise intervention.
Project description:Transcriptome analysis using the liver from young versus old mice, fed either normally or under caloric restriction reveals reorganization of distinct circadian signatures related to metabolic aging and nutrient-dependent counterbalance of aging by caloric restriction
Project description:Astrocytes are key cells in brain aging, helping neurons to undertake healthy aging or otherwise letting them enter into a spiral of neurodegeneration. We aimed to characterize astrocytes cultured from senescence-accelerated prone 8 (SAMP8) mice, a mouse model of brain pathological aging, along with the effects of caloric restriction, the most effective rejuvenating treatment known so far. Analysis of the transcriptomic profiles of SAMP8 astrocytes cultured in control conditions and treated with caloric restriction serum was performed using mRNA microarrays. A decrease in mitochondrial and ribosome mRNA, which was restored by caloric restriction, confirmed the age-related profile of SAMP8 astrocytes and the benefits of caloric restriction. An amelioration of antioxidant and neurodegeneration-related path- ways confirmed the brain benefits of caloric restriction. Studies of oxidative stress and mitochondrial function demonstrated a reduction of oxidative damage and partial improvement of mito- chondria after caloric restriction. In summary, caloric restriction showed a significant tendency to normalize pathologically aged astrocytes through the activation of pathways that are protective against the age-related deterioration of brain physiology. Key words: astrocytes; caloric restriction; mitochondria; oxidative stress; RNA microarrays; SAMP8.
Project description:We recruited ten normal-weight healthy men using inclusion criteria as previously described (Collet et al 2017). All males were healthy and not obese or overweight (average age: 23.8 years, average BMI (kg/m2): 23.3). Participants at baseline consumed a balanced diet (50% carbohydrate, 30% fat, and 20% protein). During caloric restriction, volunteers consumed 10% of normal energy requirement (226 kcal/d) for two days, again balanced (50% carbohydrate, 30% fat, and 20% protein), with the same macronutrient composition. After caloric restriction, volunteers were offered three substantial ad libitum buffet meals per day (20 MJ = 4,777 kcal) and additional snacks (16 MJ = 3,821 kcal) between meals for 2 days. They were invited to eat freely until comfortably full; food consumption was covertly measured. We collected fasting plasma samples at 0800 AM at baseline, after CR and refeeding (RF).
Project description:We used microarray analysis to further our understanding of the mode of action of the well know caloric restriction mimetic rapamycin and the compound Allantoin first studied in the context of aging in this study. His work helps build on our understanding of potential caloric restriction mimetics predicted from our bioinformatic aproach of quering the Connectivity Map, a database of drug-induced gene expression profiles, using the transcriptional profile of CR to identify drugs that induce a similar or opposite gene expression profile. Wild type worms of eat-2 mutants (a model of caloric restriction) were treated with the compounds of study with 2% DMSO or DMSO alone to serve as controls. All samples were peformed in triplicate.
Project description:Caloric Restriction in Leptin Deficiency Worsens Myocardial Steatosis: Failure to Upregulate PPAR gamma and Thermogenic Glyecrolipid/Fatty Acid Cycling Growing evidence supports an anti-lipotoxic role for leptin in preventing inappropriate peripheral tissue lipid deposition. Obese, leptin deficient ob/ob mice develop left ventricular (LV) hypertrophy and myocardial steatosis with increased apoptosis and decreased longevity. Here we investigated the cardiac effects of caloric restriction in leptin deficiency. Echocardiography was performed on C57Bl/6 wild-type mice (WT) and 7-month-old ob/ob mice fed ad lib, leptin-repleted (LR-ob/ob), or calorie-restricted (CR-ob/ob) for four weeks. Ventricular tissue was examined by electron microscopy (EM), mitochondrial coupling assay, and microarray expression profiling. LR and CR-ob/ob mice showed decreased body weight, heart weight, and LV wall thickness compared to ad lib ob/ob mice. LV fractional shortening was decreased in ad lib ob/ob mice, but restored to WT levels in LR and CR groups. However, EM revealed severe cardiac steatosis in the CR-ob/ob group compared to only moderate steatosis in ad lib ob/ob . Despite marked cardiac steatosis, CR (like LR) restored mitochondrial coupling to WT levels. CR up-regulated genes associated with oxidative stress and cell death, changes suggestive of cardiac lipotoxicity. LR, but not CR was shown to induce core genes involved in glycerolipid/free fatty acid cycling, a highly thermogenic pathway that can reduce intracellular lipid stores. LR, but not CR up-regulated and restored PGC1 and PPARto wild type levels; CR paradoxically further suppressed cardiac PPAR. Thus, leptin is essential in protecting the heart from lipotoxicity, and the inability to up-regulate the thermogenic glycerolipid/free fatty acid cycling pathway may impair the response of leptin deficient animals to the lipotoxic stress of calorie restriction. 6 month aged ob/ob mice were either leptin repleted with osmotic mini-pumps, calorie restricted to match the caloric intake of the leptin repleted mice, or fed ad lib for one month. 6-8 month C57Bl/6J mice were aged to serve as controls.