Project description:Presbycusis is characterized by an age-related progressive decline of auditory function, and arises mainly from the degeneration of hair cells or spiral ganglion (SG) cells in the cochlea. Here we show that caloric restriction suppresses apoptotic cell death in the mouse cochlea and prevents late onset of presbycusis. Caloric restricted mice, which maintained body weight at the same level as that of young control (YC) mice, retained normal hearing and showed no cochlear degeneration. CR mice also showed significantly fewer TUNEL-positive staining cells and fewer cleaved caspase-3-positive staining cells relative to middle-age control (MC) mice. Microarray analysis revealed that CR down-regulated the expression of 28 proapoptotic genes, including Bak and Bim. Taken together, our findings suggest that loss of critical cells through apoptosis is an important mechanism of presbycusis in mammals, and that CR or staying lean can retard this process by suppressing apoptosis in the inner ear tissue. Experiment Overall Design: To examine the effects of aging, a comparison of cochlea tissues from YC (3 samples) and MC (3 samples) mice was conducted. To examine the effects of calorie restriction (CR), a comparison of cochleae from MC (3 samples) and CR (3 samples) mice was conducted. We examined age-related changes in gene expression in the cochlea and calorie restriction-induced changes in gene expression in the cochlea. We pooled four cochleae from two mice for one sample and used three samples per group (n = 3). Quality control measures were not used. No replicates were done. Dye swap was not used.
Project description:Presbycusis is characterized by an age-related progressive decline of auditory function, and arises mainly from the degeneration of hair cells or spiral ganglion (SG) cells in the cochlea. Here we show that caloric restriction suppresses apoptotic cell death in the mouse cochlea and prevents late onset of presbycusis. Caloric restricted mice, which maintained body weight at the same level as that of young control (YC) mice, retained normal hearing and showed no cochlear degeneration. CR mice also showed significantly fewer TUNEL-positive staining cells and fewer cleaved caspase-3-positive staining cells relative to middle-age control (MC) mice. Microarray analysis revealed that CR down-regulated the expression of 28 proapoptotic genes, including Bak and Bim. Taken together, our findings suggest that loss of critical cells through apoptosis is an important mechanism of presbycusis in mammals, and that CR or staying lean can retard this process by suppressing apoptosis in the inner ear tissue. Keywords: Effect of aging, effect of caloric restriction, time course, disease state analysis
Project description:Epigenetic information can be inherited through the mammalian germline, and represents a plausible transgenerational carrier of environmental information. To test whether transgenerational inheritance of environmental information occurs in mammals, we carried out an expression profiling screen for genes in mice that responded to paternal diet. Characterising the change in RNA expression in sperm in response to different paternal diets. Examination of the effect of different diets, control diet, low-protein diet and caloric-restriction diet, on the RNA expression in the sperm. 8 samples: 3 are control diets and 2 are low protein diets 1 caloric restriction diet, and 2 samples from Epidydimal tissue.
Project description:Obesity, a major risk factor for chronic diseases, is related to dsyfunctional adipose tissue signaling. First human trials suggest benefits of intermittent calorie restriction diet (ICR) in chronic disease prevention that may exceed those of continuous calorie restriction diet (CCR), even at equal net calorie intake. The effect of intermittent calorie restriction on adipose tissue signaling has not been investigated to date. Thus we initiated a randomized controlled trial to analyze the effect of ICR (eu-caloric diet on five days and two days per week with energy restriction of 75%), CCR (daily energy restriction of 20%) and a control group on subcutaneous adipose tissue (SAT) gene expression. 150 overweight or obese non-smoking adults (50 per group, 50% women) were randomly asiged to one of the study arms. SAT biopsies were taken before and after the 12 week intervention phase.
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.