Summary Conditions and comorbidities of obesity mirror those of ageing and age‐related diseases. Obesity and ageing share a similar spectrum of phenotypes such as compromised genomic integrity, impaired mitochondrial function, accumulation of intracellular macromolecules, weakened immunity, shifts in tissue and body composition, and enhanced systemic inflammation. Moreover, it has been shown that obesity reduces life expectancy by 5.8 years in men and 7.1 years in women after the age of 40. Shorter life expectancy could be because obesity holistically accelerates ageing at multiple levels. Besides jeopardizing nuclear DNA and mitochondrial DNA integrity, obesity modifies the DNA methylation pattern, which is associated with epigenetic ageing in different tissues. Additionally, other signs of ageing are seen in individuals with obesity including telomere shortening, systemic inflammation, and functional declines. This review aims to show how obesity and ageing are “two sides of the same coin” through discussing how obesity predisposes an individual to age‐related conditions, illness, and disease. We will further demonstrate how the mechanisms that perpetuate the early‐onset of chronic diseases in obesity parallel those of ageing.
Osteolytic lesions in multiple myeloma are caused by osteoclast-mediated bone resorption and reduced bone formation. A unique feature of myeloma is a failure of bone healing after successful treatment. We observed adipocytes on trabecular bone near the resorbed area in successfully treated patients. Normal marrow adipocytes, when cocultured with myeloma cells, were reprogrammed and produced adipokines that activate osteoclastogenesis and suppress osteoblastogenesis. These adipocytes have reduced expression of peroxisome proliferator–activated receptor γ (PPARγ) mediated by recruitment of polycomb repressive complex 2 (PRC2), which modifies PPARγ promoter methylation at trimethyl lysine-27 histone H3. We confirmed the importance of methylation in the PPARγ promoter by demonstrating that adipocyte-specific knockout of EZH2, a member of the PRC2, prevents adipocyte reprogramming and reverses bone changes in a mouse model. We validated the strong correlation between the frequency of bone lesions and the expression of EZH2 in marrow adipocytes from patients in remission. These results define a role for adipocytes in genesis of myeloma-associated bone disease and that reversal of adipocyte reprogramming has therapeutic implications.
Key pointsr Doxorubicin induced functional deteriorations and elevations of USP7-related apoptotic/catabolic signalling in the senescent heart r Resveratrol protects against doxorubicin-induced alterations through the restoration of SIRT1 deacetylase activity Abstract A compromised cardiac function is often seen in elderly cancer patients receiving doxorubicin therapy. The present study tested the hypothesis that acute intervention with resveratrol, a natural anti-oxidant found in grapes and red wine, reduces the cardiotoxicity of doxorubicin through restoration of sirtuin 1 (SIRT1) deacetylase activity, and attenuation of the catabolic/apoptotic pathways orchestrated by USP7, a p53 deubiquitinating protein, using young (aged 2 months) and old (aged 10 months) senescence-accelerated mice prone 8 (SAMP8). Animals were randomised to receive saline, doxorubicin, and doxorubicin in combination with resveratrol, in the presence or absence of SIRT1 inhibitors, sirtinol or EX527. Resveratrol alone, but not in combination with either of the SIRT1 inhibitors, suppressed the doxorubicin-induced impairment of cardiac systolic function in aged animals. Doxorubicin reduced SIRT1 deacetylase activity, and elevated proteasomal activity and USP7; it also increased the protein level of p300 and ubiquitinated proteins in hearts from aged SAMP8. These doxorubicin-induced alterations were prevented by resveratrol, whereas the protective action of resveratrol was antagonised by sirtinol and EX527. In young SAMP8 hearts, resveratrol attenuated the doxorubicin-induced increases in acetylation of Foxo1 and transactivation of MuRF-1, whereas these mitigations were not found after treatment with SIRT1 inhibitors. However, the protein contents of acetylated Foxo1 and MuRF-1 were not affected by any of the drugs studied in aged SAMP8 hearts. Resveratrol also ameliorated the augmentation of pro-apoptotic markers including p53, Bax, caspase 3 activity and apoptotic DNA fragmentation induced by doxorubicin in hearts from aged animals, whereas these reductions were diminished by combined treatment with SIRT1 inhibitors. These data demonstrate that resveratrol ameliorates doxorubicin-induced cardiotoxicity in aged hearts through the restoration of SIRT1 activity to attenuate USP7-related catabolic/pro-apoptotic signalling. AbbreviationsAMPK, AMP-activated protein kinase; DR, doxorubicin + resveratrol; DRE, doxorubicin + resveratrol + EX527; DRS, doxorubicin + resveratrol + sirtinol; DV, doxorubicin and vehicle; EF, ejection fraction; FS, fractional shortening; LVEDD, left ventricle end-diastolic dimension; LVESD, left ventricle end-systolic dimension; SAMP8, senescence-accelerated mice prone 8; SC, saline control; SIRT1, sirtuin 1; TBST, Tris-buffered saline with 0.1% Tween 20; TUNEL, terminal deoxynucleotidyl transferase dUTP nick end labelling.
IMPORTANCE Previous studies that have shown tai chi to improve sleep were mainly based on subjective assessments, which might have produced results confounded by self-reporting bias. OBJECTIVE To compare the effectiveness of tai chi for improving sleep in older adults with insomnia with conventional exercise and a passive control group using actigraphy-based objective measurements. DESIGN, SETTING, AND PARTICIPANTS This randomized, 3-arm, parallel group, assessor-masked clinical trial was conducted at a single research unit in Hong Kong between August 2014 and August 2018. Eligible participants, aged 60 years or older and with chronic insomnia, were randomly allocated into tai chi training, exercise, and control groups. INTERVENTIONS 12-week tai chi training, 12-week conventional exercise, and no intervention control. MAIN OUTCOMES AND MEASURES Primary outcomes were measures taken from actigraphy sleep assessment. Secondary outcomes included remission of insomnia, insomnia treatment response, Pittsburgh Sleep Quality Index score, Insomnia Severity Index score, and self-reported sleep using a 7-day sleep diary. Assessments were performed at baseline, end of the intervention (postintervention), and 24 months after the intervention (follow-up). Data analysis was performed from September 2018 to August 2020. RESULTS A total of 320 participants (mean [SD] age, 67.3 [6.8] years; mean [SD] insomnia duration, 124.4 [134.5] months; 256 [80.0%] women) were randomly allocated into control (110 participants), exercise (105 participants), and tai chi (105 participants) groups and included in the data analysis. Compared with the control group, the exercise and tai chi groups showed improved sleep efficiency
Autophagy is an evolutionarily conserved biological process that functions to recycle protein aggregate and malfunctioned organelles. The activation of autophagy can be stimulated by a number of ways including infection, caloric restriction, and physical exercise. In addition to cellular metabolism and cell survival/death machinery, autophagy plays an important role in the maintenance of cellular homeostasis in skeletal muscle especially during physical exercise in which energy demand can be extremely high. By degrading macromolecules and subcellular organelles through the fusion of autophagosomes and lysosomes, useful materials such as amino acids can be released and re-used to sustain normal metabolism in cells. Autophagy is suggested to be involved in glucose and lipid metabolism and is proposed to be a critical physiological process in the regulation of intracellular metabolism. The effects of physical exercise on autophagy have been investigated. Although physical exercise has been demonstrated to be an autophagic inducer, cellular autophagic responses to exercise in skeletal muscle appear to be varied in different exercise protocols and disease models. It is also not known whether the exercise-induced beneficial health consequences involve the favorable modulation of cellular autophagy. Furthermore, the cellular mechanisms of exercise-induced autophagy still remain largely unclear. In this review article, we discuss the general principle of autophagy, cellular signaling of autophagy, autophagic responses to acute and chronic aerobic exercise, and the potential cross-talks among autophagy, mitochondrial biogenesis, and ubiquitination. This article aims to stimulate further studies in exercise and autophagy.
ObjectiveMetabolic syndrome (MetS) or prediabetes is a complex disorder that is defined by a clustering of cardiometabolic risk factors, including obesity, hypertriglyceridemia, reduced high-density lipoprotein (HDL) cholesterol, hypertension, and insulin resistance. Among cardiometabolic risk factors, central obesity plays a key role in the development of MetS through alterations in the secretion of adipokines and interacts with other MetS risk factors to unfavorably influence overall cardiometabolic risk. Obesity has grasped epidemic proportions in Asia, which has the highest number of people with diabetes in the world. But, the importance of central obesity in the clustering of all four MetS risk factors or vice versa in predicting severity of MetS has not yet been investigated in Asian population. Therefore, the present study examined the influence of central obesity on circulating levels of adipokines through its interaction with the clustering of cardiometabolic risk factors of MetS including hyperglycemia, hypertriglyceridemia, dyslipidemia and hypertension in Hong Kong Chinese adults.SubjectsBlood samples from 83 Hong Kong Chinese adults, who were previously screened for MetS according to the guideline of the United States National Cholesterol Education Program Expert Panel Adult Treatment Panel III criteria were selected. Insulin and adipokines, including visfatin, chemerin, plasminogen activator inhibitor-1 (PAI-1), resistin, C-C motif chemokine ligand 2 (CCL-2), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), tumour necrosis factor-α (TNF-α), leptin and adiponectin were assessed.ResultsThe interacting effect of central obesity with all of the other four MetS risk factors increased the proinflammatory status of adipokines (TNF-α, leptin) and decreased the anti-inflammatory status of adipokine (adiponectin).ConclusionOur results indicate that the inflammatory status of MetS may be more severe in the presence of central obesity. Adipokines, as biomarkers for pathophysiological changes, may help to improve early patient identification and to predict MetS-associated morbidity and mortality.
Tai Chi Chuan (TCC), a traditional Chinese martial art, is well-documented to result in beneficial consequences in physical and mental health. TCC is regarded as a mind-body exercise that is comprised of physical exercise and meditation. Favorable effects of TCC on body balance, gait, bone mineral density, metabolic parameters, anxiety, depression, cognitive function, and sleep have been previously reported. However, the underlying mechanisms explaining the effects of TCC remain largely unclear. Recently, advances in neuroimaging technology have offered new investigative opportunities to reveal the effects of TCC on anatomical morphologies and neurological activities in different regions of the brain. These neuroimaging findings have provided new clues for revealing the mechanisms behind the observed effects of TCC. In this review paper, we discussed the possible effects of TCC-induced modulation of brain morphology, functional homogeneity and connectivity, regional activity and macro-scale network activity on health. Moreover, we identified possible links between the alterations in brain and beneficial effects of TCC, such as improved motor functions, pain perception, metabolic profile, cognitive functions, mental health and sleep quality. This paper aimed to stimulate further mechanistic neuroimaging studies in TCC and its effects on brain morphology, functional homogeneity and connectivity, regional activity and macro-scale network activity, which ultimately lead to a better understanding of the mechanisms responsible for the beneficial effects of TCC on human health.
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