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Coen, P. M.

Publications and source records attributed to Coen, P. M..

9 recordsLinked to original sources

Integrative Multi-omics Analysis of the Human Skeletal Muscle Response to Endurance or Resistance Exercise: Findings from the Molecular Transducers of Physical Activity Consortium (MoTrPAC)

The Molecular Transducers of Physical Activity Consortium (MoTrPAC) was established to systematically characterize the molecular basis of the health benefits of exercise. Here, we present the integrative, multi-omics response of human skeletal muscle to acute endurance (EE) and resistance (RE) exercise. Distinct temporal responses were observed, with changes in ATAC-seq, phosphoproteome, and metabolome occurring before changes in the transcriptome and proteome. These distinct temporal multi-omic dynamics were used to identify transcriptional regulatory hubs converging around MEF2A and NFIC regulation of autophagy, angiogenesis and metabolism. Further, early RE-specific phosphoproteome signatures counteracted epigenetic modifications and downregulated transcripts involved in protein turnover. Additional findings include suppression of HIPK2/3 kinase signatures linked to the acute exercise regulation of sarcomeric proteins TTN, NEB, ANKRD2 and LMOD2. Our data demonstrate distinct temporal regulation across the multi-omic landscape of human skeletal muscle, with EE and RE eliciting common and unique molecular signatures.

systems biology↗

Multi-Omic, Multi-Tissue Responses to Acute Exercise in Sedentary Adults: Findings from the Molecular Transducers of Physical Activity Consortium

Regular physical activity represents one of the greatest mechanisms for maintaining human health, yet the underlying molecular transducers of these benefits remain incompletely understood. Multi-omic assays now provide new opportunities to study the coordinated molecular responses of body tissues to different exercise modalities. The Molecular Transducers of Physical Activity Consortium (MoTrPAC) was established to address this need by creating a molecular map of the response to physical activity. Described here is the first human cohort of MoTrPAC: sedentary adults enrolled prior to study suspension during the COVID-19 pandemic (N=175) randomized to either endurance or resistance exercise, or non-exercise control. From these participants, we detail their global acute molecular response in skeletal muscle, adipose tissue, and blood, integrated at multiple levels: tissue, exercise modality, timepoint, and omic category. These analyses characterize key molecular pathways, identify central regulators, and implicate novel candidate exerkines in mediating multi-organ exercise effects.

systems biology↗

MicroRNA regulatory targets of VO2peak in older adult participants of the Study of Muscle Mobility and Aging (SOMMA)

Skeletal muscle aging (sarcopenia) is associated with reduced peak oxygen consumption (VO peak) during exercise, a key determinant of physical function and overall health. However, the molecular mechanisms linking muscle aging to low VO peak remain poorly understood. We aimed to identify miRNA signatures and miRNA-gene regulatory networks associated with VO peak in older adults. Using small RNA and mRNA sequencing, we analyzed skeletal muscle from 72 SOMMA participants (70-79 years old) with low or high VO peak (n = 18/group) and from 36 participants spanning the full VO peak spectrum. Differential expression was assessed using LIMMA, with pathway and network analyses performed using Ingenuity Pathway Analysis (IPA) and Weighted Gene Co-expression Network Analysis (WGCNA). We detected 1,408 miRNAs and 16,210 genes; among these, 14 miRNAs and 2,018 genes were differentially expressed (FDR < 0.05). The 14 miRNAs regulated 142 genes, and expression of 10 miRNAs inversely correlated with 50 genes enriched in mitochondrial, sirtuin-1, and nitric oxide signaling pathways. Regression analyses identified 21 miRNAs and 1,744 genes significantly correlated with VO peak after adjusting for age and sex. WGCNA revealed 10 co-expression modules associated with VO peak, with the cyan module showing the strongest correlation and enrichment for nitric oxide signaling genes. These findings highlight novel miRNA-mediated molecular pathways potentially contributing to low VO peak and skeletal muscle aging in older adults. Future studies will further investigate these miRNA-gene interactions to uncover therapeutic targets for preserving muscle function with age.

molecular biology↗

Mitochondrial uncoupler BAM15 improves skeletal muscle function and mitochondrial respiration in Sarcopenia

BackgroundAgeing is accompanied by progressive declines in skeletal muscle mass and strength, culminating in sarcopenia, a condition that contributes to frailty, multimorbidity, and mortality. Age-related changes to mitochondria lead to oxidative damage and dysfunction and are proposed to occur early in the trajectory of sarcopenia, supporting the candidacy of mitochondrial-protective therapies. Here, we test the efficacy of mitochondrial uncoupler BAM15 in age-dependent sarcopenic mouse models. MethodsMale and female MitoQC mice aged 24 months received either standard chow or chow supplemented with BAM15 (0.033% mg/g) ad libitum for eight weeks (n=13-14/group). Young (3-month-old) mice served as reference controls (n=8/group). Muscle mitochondrial respiration was assessed in permeabilized fib res, and contractile function was measured in isolated extensor digitorum longus and soleus muscles. Mitophagy was quantified by immunofluorescence confocal microscopy. Data were analyzed using one-or two-way ANOVA followed by Dunnetts or Bonferronis multiple comparison tests. ResultsAged male and female mice exhibited reduced gastrocnemius muscle mass relative to body mass compared with young controls (p<0.05; [~]18% and [~]32% loss, respectively). BAM15 did not alter muscle size but reversed the age-related loss of contractile function in EDL muscles, to that of the young reference controls in both sexes (p<0.05; [~]33% in males, [~]16% in females). In male mice, BAM15 improved mitochondrial efficiency, evidenced by restoration of Complex I-linked respiration and decreased proton leak ([~]52% improvement; p<0.05), and normalized protein levels of oxidative stress marker 4 -HNE, without changes in mitophagy or mitochondrial content. In females, BAM15 did not improve mitochondrial parameters, which may be, in part, due to aged female muscle exhibiting unchanged Complex I leak and 4-HNE protein abundance, alongside lower complex I subunit (NDUFB8) protein abundance. ConclusionsBAM15 improved skeletal muscle mitochondrial efficiency and contractile function in aged male mice, supporting the potential of mitochondrial uncoupling as a therapeutic strategy for sarcopenia.

physiology↗

Microgravity Accelerates Skeletal Muscle Degeneration: Functional and Transcriptomic Insights from a Muscle Lab-on-Chip Model Onboard the ISS.

Microgravity accelerates skeletal muscle degeneration, mimicking aging, yet its effects on human muscle cell function and signaling remain underexplored. Using a muscle lab-on-chip model onboard the International Space Station, we examined how microgravity and electrically stimulated contractions influence muscle biology and age-related muscle changes. Our 3D bioengineered muscle model, cultured for 21 days (12 days in microgravity), included myobundles from young, active and older, sedentary individuals, with and without electrically stimulated contraction. Real-time data collected within an autonomous Space Tango CubeLabTM showed reduced contraction magnitude in microgravity. Global transcriptomic analysis revealed increased gene expression and particularly mitochondrial-related gene expression in microgravity for the electrically stimulated younger myobundles, while the older myobundles were less responsive. Moreover, a comparative analysis using a skeletal muscle aging gene expression database revealed that certain age-induced genes showed changes in expression in myobundles from the younger cohort when exposed to microgravity, whereas these genes remained unchanged in myobundles from the older cohort. Younger, electrically stimulated myobundles in microgravity exhibited higher expression of 45 aging genes involved in key aging pathways related to inflammation and immune function, mitochondrial dysfunction, and cellular stress; and decreased expression of 41 aging genes associated with inflammation, and cell growth. This study highlights a unique age-related molecular signature in muscle cells exposed to microgravity and underscores electrical stimulation as a potential countermeasure. These insights advance understanding of skeletal muscle aging and microgravity-induced degeneration, informing strategies for mitigating age-related muscle atrophy in space and on Earth.

cell biology↗

MicroRNA signatures of VO2peak in older adult participants of the Study of Muscle, Mobility and Aging

BackgroundPeak oxygen consumption during exercise (VO2peak), is a direct measure of cardiorespiratory fitness (CF), a key indicator of physical function and overall health. However, the molecular changes that underpin VO2peak variation are not clear. Our objective is to understand the miRNA signatures that relate to VO2peak variation, which could provide insights to novel mechanisms that contribute to low VO2peak. MethodsWe used small RNA sequencing to analyze serum samples from 72 participants (70-79 yrs old, 53% female) of the Study of Muscle, Mobility and Aging (SOMMA). We analyzed samples from individuals with low or high VO2peak (N=18/group) as well as samples from 36 randomly selected participants spanning the entire spectrum of VO2peak. We used LIMMA analysis package for regression analysis and to identify differentially expressed miRNAs. We used receiver operating characteristic curve analysis to evaluate the Area Under the Curve (AUC) and sensitivity and specificity rates. ResultsWe identified 1,055 miRNAs expressed in all serum samples. Expression of 65 miRNAs differed between participants with low and high VO2peak (p < 0.05). After p-value adjustment, expression of 5 miRNAs (miR-1301-3p, -431-5p, -501-5p, -519a-3p, and -18a-3p) remained significantly different (FDR = 0.05). The five miRNAs had AUC ranging from 0.77 to 0.84. The optimal sensitivity and specificity ranged from 70 to 80% and 80 to 90%, respectively. After adjustment for age and sex covariates, 46 miRNAs significantly correlated with VO2peak (p < 0.05) and miR-519a-3p remained significant based on adjusted of p-values. ConclusionsWe identified a miRNA signature of VO2peak in older individuals that might provide insights to novel mechanisms that drive low VO2peak. Future studies will validate the findings in a larger, longitudinal study cohort.

molecular biology↗

The mitochondrial multi-omic response to exercise training across tissues

Mitochondria are adaptable organelles with diverse cellular functions critical to whole-body metabolic homeostasis. While chronic endurance exercise training is known to alter mitochondrial activity, these adaptations have not yet been systematically characterized. Here, the Molecular Transducers of Physical Activity Consortium (MoTrPAC) mapped the longitudinal, multi-omic changes in mitochondrial analytes across 19 tissues in male and female rats endurance trained for 1, 2, 4 or 8 weeks. Training elicited substantial changes in the adrenal gland, brown adipose, colon, heart and skeletal muscle, while we detected mild responses in the brain, lung, small intestine and testes. The colon response was characterized by non-linear dynamics that resulted in upregulation of mitochondrial function that was more prominent in females. Brown adipose and adrenal tissues were characterized by substantial downregulation of mitochondrial pathways. Training induced a previously unrecognized robust upregulation of mitochondrial protein abundance and acetylation in the liver, and a concomitant shift in lipid metabolism. The striated muscles demonstrated a highly coordinated response to increase oxidative capacity, with the majority of changes occurring in protein abundance and post-translational modifications. We identified exercise upregulated networks that are downregulated in human type 2 diabetes and liver cirrhosis. In both cases HSD17B10, a central dehydrogenase in multiple metabolic pathways and mitochondrial tRNA maturation, was the main hub. In summary, we provide a multi-omic, cross-tissue atlas of the mitochondrial response to training and identify candidates for prevention of disease-associated mitochondrial dysfunction.

molecular biology↗

Metabolite profile and mitochondrial energetics characterize poor early recovery of muscle mass following hind limb unloading in old mice

The progression of age-related sarcopenia can be accelerated by impaired recovery of muscle mass following periods of disuse due to illness or immobilization. The molecular underpinnings of poor recovery of aging muscle following disuse remain largely unknown. However, recent evidence suggests that mitochondrial energetics may play an important role. Here, we report that 22-24 month old mice with low muscle mass and insulin resistance display poor early recovery of muscle mass following 10 days of hind limb unloading. We took an unbiased approach to identify changes in energy metabolism gene expression and metabolite pools and show for the first time that persistent mitochondrial dysfunction, dysregulated fatty acid {beta}-oxidation and elevated H2O2 emission underlie poor early recovery of muscle mass following a period of disuse in old mice. Importantly, this is linked to more severe whole-body insulin resistance. The findings suggest that muscle fuel metabolism and mitochondrial energetics should be a focus for mining therapeutic targets to improve recovery of muscle mass following periods of disuse in older animals.

physiology↗

Physical activity unveils the relationship between mitochondrial energetics, muscle quality and physical function in older adults

BackgroundThe concept of mitochondrial dysfunction in aging muscle is highly controversial. In addition, emerging evidence suggests that reduced muscle oxidative capacity and efficiency underlie the etiology of mobility loss in older adults. Here, we hypothesized that studying well phenotyped older cohorts across a wide range of physical activity would unveil a range of mitochondrial function in skeletal muscle and in turn allow us to more clearly examine the impact of age per se on mitochondrial energetics. This also enabled us to more clearly define the relationships between mitochondrial energetics and muscle lipid content with clinically relevant assessments of muscle and physical function.\n\nMethodsThirty-nine volunteers were recruited to the following study groups; Young Active (YA, n=2F/8M, age=31.2{+/-}5.4 yrs.). Older Active (OA, n=2F/8M, age=67.5{+/-}2.7 yrs.) and Older Sedentary (OS, n=8F/11M, age=70.7{+/-}4.7 yrs.). Participants completed a graded exercise test to determine fitness (VO2peak), a submaximal exercise test to determine exercise efficiency, and daily physical activity (PA) was recorded using a tri-axial armband accelerometer. Mitochondrial energetics were determined by 1) 31P magnetic resonance spectroscopy and 2) respirometry of fiber bundles from vastus lateralis biopsies. Quadriceps function was assessed by isokinetic dynamometry and physical function by the short physical performance battery (SPPB) and stair climb test.\n\nResultsDaily PA energy expenditure was significantly lower in OS, compared to YA and OA groups. Despite fitness being higher in YA compared to OA and OS, mitochondrial respiration, ATPMax, P/O ratio and exercise efficiency were similar in YA and OA groups and were significantly lower in OS. P/O ratio was correlated with exercise efficiency. Time to complete the stair climb and repeated chair stand tests was significantly greater for OS. Interestingly, ATPMax was related to muscle contractile performance and physical function.\n\nConclusionsOlder adults who maintain a high amount of physical activity have better mitochondrial capacity, similar to highly active younger adults, and this is related to their better muscle quality, exercise efficiency and physical performance. This suggests that mitochondria could be an important therapeutic target for sedentary aging associated conditions including sarcopenia, dynapenia and loss of physical function.

physiology↗