The number of older obese adults is increasing worldwide. Whether obese adults show similar health benefits in response to lifestyle interventions at different ages is unknown. The study enrolled 25 obese men (body mass index: 31-39 kg/m2) in two arms according to age (30-40 and 60-70 yr old). Participants underwent an 8-wk intervention with moderate calorie restriction (∼20% below individual energy requirements) and supervised endurance training resulting in ∼5% weight loss. Body composition was measured using dual energy X-ray absorptiometry. Insulin sensitivity was assessed during a hypersinsulinemic-euglycemic clamp. Cardiometabolic profile was derived from blood parameters. Subcutaneous fat and vastus lateralis muscle biopsies were used for ex vivo analyses. Two-way repeated-measure ANOVA and linear mixed models were used to evaluate the response to lifestyle intervention and comparison between the two groups. Fat mass was decreased and bone mass was preserved in the two groups after intervention. Muscle mass decreased significantly in older obese men. Cardiovascular risk (Framingham risk score, plasma triglyceride, and cholesterol) and insulin sensitivity were greatly improved to a similar extent in the two age groups after intervention. Changes in adipose tissue and skeletal muscle transcriptomes were marginal. Analysis of the differential response to the lifestyle intervention showed tenuous differences between age groups. These data suggest that lifestyle intervention combining calorie restriction and exercise shows similar beneficial effects on cardiometabolic risk and insulin sensitivity in younger and older obese men. However, attention must be paid to potential loss of muscle mass in response to weight loss in older obese men.NEW & NOTEWORTHY Rise in obesity and aging worldwide are major trends of critical importance in public health. This study addresses a current challenge in obesity management. Do older obese adults respond differently to a lifestyle intervention composed of moderate calorie restriction and supervised physical activity than younger ones? The main conclusion of the study is that older and younger obese men similarly benefit from the intervention in terms of cardiometabolic risk.
- Klíčová slova
- aging, calorie restriction, cardiometabolic risk, obesity, physical exercise,
- MeSH
- dospělí MeSH
- fyziologická adaptace * MeSH
- kardiovaskulární systém metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- obezita metabolismus MeSH
- programy na snížení hmotnosti * MeSH
- senioři MeSH
- složení těla MeSH
- věkové faktory MeSH
- životní styl * MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
- klinické zkoušky MeSH
- práce podpořená grantem MeSH
BACKGROUND: The adipose tissue (AT) is a secretory organ producing a wide variety of factors that participate in the genesis of metabolic disorders linked to excess fat mass. Weight loss improves obesity-related disorders. OBJECTIVES: Transcriptomic studies on human AT, and a combination of analyses of transcriptome and proteome profiling of conditioned media from adipocytes and stromal cells isolated from human AT, have led to the identification of apolipoprotein M (apoM) as a putative adipokine. We aimed to validate apoM as novel adipokine, investigate the relation of AT APOM expression with metabolic syndrome and insulin sensitivity, and study the regulation of its expression in AT and secretion during calorie restriction-induced weight loss. METHODS: We examined APOM mRNA level and secretion in AT from 485 individuals enrolled in 5 independent clinical trials, and in vitro in human multipotent adipose-derived stem cell adipocytes. APOM expression and secretion were measured during dieting. RESULTS: APOM was expressed in human subcutaneous and visceral AT, mainly by adipocytes. ApoM was released into circulation from AT, and plasma apoM concentrations correlate with AT APOM mRNA levels. In AT, APOM expression inversely correlated with adipocyte size, was lower in obese compared to lean individuals, and reduced in subjects with metabolic syndrome and type 2 diabetes. Regardless of fat depot, there was a positive relation between AT APOM expression and systemic insulin sensitivity, independently of fat mass and plasma HDL cholesterol. In human multipotent adipose-derived stem cell adipocytes, APOM expression was enhanced by insulin-sensitizing peroxisome proliferator-activated receptor agonists and inhibited by tumor necrosis factor α, a cytokine that causes insulin resistance. In obese individuals, calorie restriction increased AT APOM expression and secretion. CONCLUSIONS: ApoM is a novel adipokine, the expression of which is a hallmark of healthy AT and is upregulated by calorie restriction. AT apoM deserves further investigation as a potential biomarker of risk for diabetes and cardiovascular diseases.
- Klíčová slova
- adipokine, adipose tissue, calorie restriction, diet, glucose homeostasis, insulin resistance, lipocalin, metabolic syndrome, obesity,
- MeSH
- adipokiny genetika metabolismus MeSH
- apolipoproteiny M genetika metabolismus MeSH
- kalorická restrikce MeSH
- klinické zkoušky jako téma MeSH
- kohortové studie MeSH
- lidé středního věku MeSH
- lidé MeSH
- longitudinální studie MeSH
- obezita dietoterapie genetika metabolismus MeSH
- průřezové studie MeSH
- tukové buňky metabolismus MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- adipokiny MeSH
- apolipoproteiny M MeSH
Impaired adipose tissue insulin signalling is a critical feature of insulin resistance. Here we identify a pathway linking the lipolytic enzyme hormone-sensitive lipase (HSL) to insulin action via the glucose-responsive transcription factor ChREBP and its target, the fatty acid elongase ELOVL6. Genetic inhibition of HSL in human adipocytes and mouse adipose tissue results in enhanced insulin sensitivity and induction of ELOVL6. ELOVL6 promotes an increase in phospholipid oleic acid, which modifies plasma membrane fluidity and enhances insulin signalling. HSL deficiency-mediated effects are suppressed by gene silencing of ChREBP and ELOVL6. Mechanistically, physical interaction between HSL, independent of lipase activity, and the isoform activated by glucose metabolism ChREBPα impairs ChREBPα translocation into the nucleus and induction of ChREBPβ, the isoform with high transcriptional activity that is strongly associated with whole-body insulin sensitivity. Targeting the HSL-ChREBP interaction may allow therapeutic strategies for the restoration of insulin sensitivity.
- Klíčová slova
- ChREBP, ELOVL Fatty Acid Elongase 6, ELOVL6 Expression, Hormone-sensitive Lipase, Insulin Signaling,
- MeSH
- biologické markery MeSH
- elongasy mastných kyselin genetika metabolismus MeSH
- exprese genu MeSH
- fluidita membrány genetika MeSH
- glukosa metabolismus MeSH
- inzulin metabolismus MeSH
- inzulinová rezistence * genetika MeSH
- mapování interakce mezi proteiny MeSH
- mapy interakcí proteinů MeSH
- myši transgenní MeSH
- myši MeSH
- signální transdukce MeSH
- sterolesterasa metabolismus MeSH
- transkripční faktory BHLH-Zip metabolismus MeSH
- tuková tkáň metabolismus MeSH
- tukové buňky metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biologické markery MeSH
- elongasy mastných kyselin MeSH
- Elovl6 protein, mouse MeSH Prohlížeč
- glukosa MeSH
- inzulin MeSH
- Mlxipl protein, mouse MeSH Prohlížeč
- sterolesterasa MeSH
- transkripční faktory BHLH-Zip MeSH
Nutrigenomics investigates relationships between nutrients and all genome-encoded molecular entities. This holistic approach requires systems biology to scrutinize the effects of diet on tissue biology. To decipher the adipose tissue (AT) response to diet induced weight changes we focused on key molecular (lipids and transcripts) AT species during a longitudinal dietary intervention. To obtain a systems model, a network approach was used to combine all sets of variables (bio-clinical, fatty acids and mRNA levels) and get an overview of their interactions. AT fatty acids and mRNA levels were quantified in 135 obese women at baseline, after an 8-week low calorie diet (LCD) and after 6 months of ad libitum weight maintenance diet (WMD). After LCD, individuals were stratified a posteriori according to weight change during WMD. A 3 steps approach was used to infer a global model involving the 3 sets of variables. It consisted in inferring intra-omic networks with sparse partial correlations and inter-omic networks with regularized canonical correlation analysis and finally combining the obtained omic-specific network in a single global model. The resulting networks were analyzed using node clustering, systematic important node extraction and cluster comparisons. Overall, AT showed both constant and phase-specific biological signatures in response to dietary intervention. AT from women regaining weight displayed growth factors, angiogenesis and proliferation signaling signatures, suggesting unfavorable tissue hyperplasia. By contrast, after LCD a strong positive relationship between AT myristoleic acid (a fatty acid with low AT level) content and de novo lipogenesis mRNAs was found. This relationship was also observed, after WMD, in the group of women that continued to lose weight. This original system biology approach provides novel insight in the AT response to weight control by highlighting the central role of myristoleic acid that may account for the beneficial effects of weight loss.
- MeSH
- dospělí MeSH
- genové regulační sítě genetika MeSH
- hmotnostní úbytek genetika fyziologie MeSH
- kalorická restrikce * MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- obezita metabolismus MeSH
- stanovení celkové genové exprese MeSH
- tuková tkáň metabolismus MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH