bims-mimead 2026-05-31 papers

Issue of 2026–05–31
six papers selected by
Rachel M. Handy, University of Guelph

Exp Gerontol. 2026 May 27. pii: S0531-5565(26)00165-8. [Epub ahead of print] 113186

Exercise stimulates microvascular perfusion of femoral adipose tissue in older females.

Ditte M Storm, Milan W Betz, Thomas Å Pedersen, Lex B Verdijk, Luc J C van Loon, Tim Snijders, Gijs H Goossens.

Adipose tissue and skeletal muscle are metabolically active tissues that play a central role in whole-body energy homeostasis. The functionality of these tissues, and hence cardiometabolic health, relies on adequate adjustments in perfusion reflecting metabolic demands in different physiological conditions. Acute exercise increases skeletal muscle perfusion, and this response can be enhanced by prolonged exercise training. Yet, whether similar responses occur in adipose tissue remains unclear. Here, we investigated the effect of a single bout of resistance exercise on adipose tissue microvascular perfusion in healthy older females. Moreover, we explored the effects of 8 weeks of aerobic exercise training on the microvascular perfusion response to acute resistance exercise. Study participants (age: 70 ± 4 y; BMI: 24.7 ± 2.8 kg/m2) were assigned to either a supervised aerobic exercise training (3 times/week) or a no training control group. Before and after the intervention period, microvascular blood volume was measured in femoral adipose tissue and the adjacent skeletal muscle using contrast-enhanced ultrasound. More specifically, the measurements were conducted at rest and at t = 10 and t = 40 min after a single resistance exercise session. We found that microvascular blood volume increased in both adipose (3.0 ± 2.5-fold, p < 0.05) and skeletal muscle (4.5 ± 1.9-fold, p = 0.001) tissue after the resistance exercise session. Eight weeks of aerobic exercise training improved adipose tissue microvascular perfusion after acute resistance exercise compared to the control group (time x group, p = 0.033), without significant within-group changes. The present findings indicate that microvascular blood volume in femoral adipose tissue increases after an acute bout of resistance exercise and may be enhanced following exercise training in healthy older females.

Keywords: Adipose tissue; Aging; Metabolism; Perfusion; Resistance exercise; Skeletal muscle

DOI: https://doi.org/10.1016/j.exger.2026.113186

J Physiol. 2026 May 28.

Skeletal muscle proteomics links mitochondrial abundance with peak fat oxidation in physically active young males.

Eloise K Tarry, Shaun Mason, Ghazanfar Abbas Khan, Sofie G Vestergaard, Emilie A Petersen, Mike C Olsen, Maria Hansen, Arthur Ingersen, Kirsten F Howlett, Steen Larsen, Christopher S Shaw, Jørn W Helge.

The interindividual variability in peak fat oxidation (PFO) and the intensity at which this occurs (Fatmax) has been attributed to physiological factors, diet and physical activity; however, few studies have examined the contribution of skeletal muscle characteristics. The present study examined the relationship between PFO, Fatmax and the skeletal muscle proteome in young, physically active males. Thirty-four young, lean males were phenotyped through assessment of aerobic capacity, PFO, body composition, fasting blood samples and a muscle biopsy. Liquid chromatography mass spectrometry based proteomics was used to assess skeletal muscle protein abundance. Only absolute PFO (g min-1) was positively correlated with V̇O2peak${{\dot{V}}_{{{{\mathrm{O}}}_2}{\mathrm{peak}}}}$ (r = 0.496, P = 0.003). Few skeletal muscle proteins correlated with absolute PFO, whereas relative PFO and Fatmax were positively associated with numerous mitochondrial proteins enriched in metabolic pathways, oxidative phosphorylation and other mitochondrial processes. Mitochondrial proteome abundance was positively correlated with both relative PFO (r = 0.633, P < 0.001) and Fatmax (r = 0.595, P < 0.001). Mitochondrial complex-specific analysis demonstrated that respiratory complex V was associated with both relative PFO and Fatmax. Multiple regression analyses indicated that mitochondrial abundance and muscle glycogen explained 55% of the variability in relative PFO, whereas mitochondrial abundance alone explained 43% of the variability in Fatmax. Absolute PFO was explained by a combination of V̇O2peak${{\dot{V}}_{{{{\mathrm{O}}}_2}{\mathrm{peak}}}}$ , mitochondrial abundance and muscle glycogen content (r2 = 0.562). This untargeted proteomic approach highlights that skeletal muscle mitochondrial content contributes to the interindividual variability in PFO and Fatmax in lean, active young males. KEY POINTS: This study used an untargeted proteomics approach to explore the links between the skeletal muscle proteome and peak fat oxidation (PFO) in young, physically active males. Absolute PFO was primarily associated with maximal aerobic capacity. When expressed relative to fat-free mass, PFO was closely associated with skeletal muscle proteins enriched in oxidative metabolism and mitochondrial pathways. Mitochondrial abundance assessed by mitochondrial proteome content and citrate synthase activity was positively related to relative PFO and the intensity at which this occurs (Fatmax). Mitochondrial respiratory complex V was consistently related to both relative PFO and Fatmax. Mitochondrial content independently contributed to both PFO and Fatmax, highlighting mitochondrial content as a key determinant of the maximal capacity for fat oxidation.

Keywords: exercise; fat oxidation; metabolism; muscle; proteomics

DOI: https://doi.org/10.1113/JP290966

Nat Metab. 2026 May 27.

Glycogen drives the sensory activation of POMC neurons.

Hypothalamic POMC neurons modulate systemic energy balance and glucose homeostasis by sensing nutritional state signals. In addition to this classic regulatory mode, these neurons are also activated by the sensory perception of food. Here, we report that food-related sensory cues engage glycogen metabolism in POMC neurons. Genetic depletion of glycogen through various approaches renders POMC neurons unresponsive to food-associated sensory stimuli. This defective perception of food is linked to alterations in consummatory behaviour, hepatic adaptations and cephalic insulin release associated with a prediabetic phenotype that progresses into overweight and overt diabetes with a high-calorie diet or ageing. Collectively, our results posit glycogen as a decisive fuel resource for meeting the rapid and demanding energy requirements linked with sensory activation. Furthermore, our data delineate the biological function of food perception and provide support for the physiological relevance of neuronal glycogen.

DOI: https://doi.org/10.1038/s42255-026-01535-7

Biochem Biophys Res Commun. 2026 May 20. pii: S0006-291X(26)00761-8. [Epub ahead of print]826 153997

Preconditioning and supplementation with glutathione ameliorates oxidative stress, mitochondrial dysfunction, and restores metabolic imbalance in insulin-resistant myotubes.

Shreyada N Save, Nikhat Parveen, Ganesh Sonis, Sanskriti Chavan, Jeetender Chugh, Shilpy Sharma.

Insulin resistance, defined as the inability of the insulin-target tissues including skeletal muscles to insulin action, has been identified as a major pathophysiology associated with the development of metabolic disorders including type 2 diabetes mellitus. Palmitic acid (PA) and related saturated free fatty acids contribute significantly to the development of insulin resistance by perturbing the redox homeostasis in the cells. The deficiency of the intracellular antioxidant - glutathione (GSH) has been documented in insulin-resistant states, and dietary supplementation of GSH and its precursors has been associated with the alleviation of oxidative stress, restoration of intra-abdominal fat levels, enhancement of insulin sensitivity and glucose metabolism. However, the key metabolic pathways targeted by GSH in mediating this protection need to be identified so that they can be targeted for effective management of insulin resistance. In this study, we aimed to elucidate whether preconditioning and supplementation with GSH (0.1 and 1 mM) could alleviate the oxidative stress, mitochondrial dysfunction, and metabolic perturbations induced by PA in the L6 skeletal myotubes. Metabolic perturbations associated with the same were identified using 1H NMR spectroscopy. It was observed GSH supplementation at concentrations of 1 mM in the myotubes experiencing lipotoxicity led to the partial restoration of metabolic imbalances observed in levels of nucleotides (UMP, adenosine, AMP), GSH metabolism intermediates (glutamine, pyroglutamate), acetate, amino acids including proline, aspartate, threonine; phospholipid intermediates (o-phosphocholine, choline), niacinamide, TCA cycle intermediates (citrate), and glycerol. Thus, we believe that these metabolic pathways can be targeted for the management of lipotoxicity and insulin resistance.

Keywords: Glutathione supplementation; Insulin resistance; Metabolomics; Mitochondrial dysfunction; Oxidative stress; Palmitic acid; Skeletal muscles

DOI: https://doi.org/10.1016/j.bbrc.2026.153997

NPJ Aging. 2026 May 25.

Time-restricted feeding improves functional capacity of adipose-derived stem cells with activation of OSK-associated transcriptional programs.

Rui Zhang, Xingxiang Duan, Wanyang Zhong, Yan Deng, Ziping Wang, Junnan Wang, Yan He, Shuang Rong, Qingsong Ye.

Time-restricted feeding (TRF), a circadian-based dietary intervention, has emerged as a promising strategy to counteract metabolic and age-related dysfunctions. However, how TRF can reverse stem cell aging and restore tissue regenerative potential remains unclear. In this study, we investigated the effects of long-term TRF on senescent adipose-derived stem cells (ADSCs) in a high-fat diet (HFD) induced aged mice model. Mice were assigned to standard or HFD diets under ad libitum or TRF (8 h/day) regimens for 7 months. TRF effectively attenuated HFD-induced weight gain and metabolic inflexibility. Functionally, TRF preserved ADSC morphology and mitochondrial integrity, restored proliferation and migration capacity. Restored balanced lineage differentiation and markedly reduced senescence markers, reactive oxygen species, and inflammatory cytokines. TRF was associated with increased expression of Oct4, Sox2, and Klf4 (OSK) in ADSCs. Lentiviral overexpression of OSK partially recapitulated restoration-associated phenotypes in vitro. However, while OSK overexpression was sufficient to induce these changes, the present data do not establish a necessary role for OSK in mediating TRF-induced effects. Analysis of adipose tissue was consistent with the cell assay, confirming that TRF alleviated fibrosis and inflammation in aged adipose tissue. We find TRF as a noninvasive, physiologically safe intervention to restore aged stem cell function and tissue homeostasis during aging.

DOI: https://doi.org/10.1038/s41514-026-00411-8

Sports (Basel). 2026 May 15. pii: 204. [Epub ahead of print]14(5):

Effects of 12-Week Multicomponent Training Program on Body Composition, Metabolic Health, and Physical Performance in Middle-Aged and Older Women: Exploratory Role of Baseline Adiposity.

Citlali Campos-Hernández, Tatiana Romero-García, Héctor Frayde-Gómez, Cristhian Emmanuel López-Campos, María Jossé Navarro-Ibarra, Juan Carlos Borbón-Román, Juan Pablo Machado-Parra, Victor Enrique Porras-Alvarado, Mario Israel Oregel-Cortez.

Combined functional training (FT), high-intensity interval training (HIIT) and aquatic exercise may improve health-related fitness in aging populations; however, the influence of baseline adiposity on training responses remains unclear. This study evaluated the effects of a 12-week multicomponent training program on aerobic capacity, body composition, metabolic health, and physical performance in middle-aged and older women and explored whether baseline body fat percentage modulated these responses. Thirty-four women (50-72 years) were assigned to a control group (Ctrl, n = 10) or an exercise group, stratified into normal fat (NF%, n = 10) and high fat (HF%, n = 14). The intervention included three weekly 60 min sessions consisting of HIIT, FT, and aquatic-based interval and resistance exercises, while controls maintained their habitual lifestyle without structured exercise. Significant improvements were observed in VO2max, skeletal muscle mass, fasting insulin, triglycerides, total cholesterol, HDL cholesterol, and functional performance. Baseline adiposity influenced metabolic adaptations, with greater improvements in the HF% group. These findings suggest that multicomponent training may improve cardiometabolic health and physical performance; however, the results should be interpreted cautiously due to the quasi-experimental design and small sample size.

Keywords: aerobic capacity; body fat percentage; exercise intervention; functional performance; functional training; high-intensity interval training; metabolic health; middle-aged and older women

DOI: https://doi.org/10.3390/sports14050204