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Bareja, A.

Publications and source records attributed to Bareja, A..

6 recordsLinked to original sources

Regulation of Small RNAs by Exercise and Their Role in Insulin Sensitivity

We investigated effects of three aerobic exercise interventions, varying in amount and intensity with durations of 8-9-months on small RNA (smRNA) expression and regulatory pathways in skeletal muscle and plasma from 120 participants. Using untargeted smRNA sequencing focused on miRNAs and piRNAs, adjusting for demographics and bodyweight, we identified 124 muscle smRNAs altered by exercise amount and 15 by intensity, and 47 plasma smRNAs altered by intensity and one by amount. These smRNAs were enriched in metabolic, transcriptional, translational, and cell cycle pathways. Exercise-induced changes in several smRNAs-six from muscle and five from plasma-and exercise-induced reduction in body weight, aligned with improvement in insulin sensitivity (p<0.05). These findings demonstrate tissue-specific regulation of smRNAs by exercise and identify potential candidates for exercise mimetics to modulate muscle insulin sensitivity.

physiology↗

Biological Mechanisms of Strength Preservation During Calorie Restriction-Induced Weight Loss Among Young- to Middle-Aged Adults without Obesity

PurposeWeight loss is often pursued to improve cardiometabolic health and quality of life. However, rapid weight loss can lead to reductions in lean soft tissue mass and strength to compromise body composition and functional ability. Thus, identifying molecular predictors of muscular strength preservation during weight loss is critical to mitigating these effects. MethodsWe conducted a secondary analysis of the CALERIETM (Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy) trial, a two-year randomized controlled study of caloric restriction (CR) or ad-libitum intake in healthy adults without obesity. Among 198 participants, changes in whole-body mass and knee extensor strength were assessed over the first 12 months of the study which was primarily characterized by weight loss. Transcriptomic profiling was conducted in a subset of 42 participants who provided skeletal muscle samples. Linear regression was used to model the relationship between strength change and gene expression change, while controlling for changes in whole-body mass. Gene set enrichment analysis (GSEA) was performed using Hallmark pathways. Individual-level pathway analysis was performed via gene set variation analysis (GSVA). ResultsWe identified 96 out of 198 individuals (48.5%) who maintained or improved strength relative to body mass during weight loss (i.e. individuals with residuals > 0). Transcriptomics analysis on a subset of 42 individuals revealed 151 genes significantly associated with change in strength after accounting for change in whole-body mass (p < 0.01). Hub genes were identified as HSP90AA1 ({beta} = 34.45, SE = 7.32, p <0.001), EIF3A ({beta} = 36.14, SE = 10.27, p < 0.001), EIF5B ({beta} = 49.94, SE = 11.28, p < 0.001), and H3C1 ({beta} = -15.87, SE = 4.85, p < 0.001). GSEA revealed significant involvement of pathways related to cellular proliferation, immune regulation, protein secretion, and checkpoint control processes. GSVA identified a similar set of pathways. ConclusionsThese findings highlight molecular pathways supporting strength retention during CR-induced weight loss. Heat-shock protein, HSP90AA1, warrants further investigation as a candidate target for preserving muscle strength during interventions aimed at weight reduction.

molecular biology↗

Temporal Multi-Omic Analysis Uncovers Sex-Biased Molecular Programs Underlying Skeletal Muscle Adaptation to Endurance Training

BackgroundExercise training is known to benefit health and reduce disease risk. While skeletal muscle adaptations are fundamental to many of the health benefits of exercise training, the common and sex-specific molecular regulators that mediate these adaptations remain to be fully elucidated. MethodsTo this end, we leveraged skeletal muscle multi-omics data generated by the Molecular Transducers of Physical Activity Consortium (MoTrPAC), where 6 month-old male and female rats endurance trained for 1, 2, 4, or 8 weeks. Our objective was to identify shared and sex-specific multi-omic molecular responses to endurance training in skeletal muscle, and relate them to phenotypic adaptations. ResultsWe identified largely sexually-conserved transcriptomic and proteomic pathway enrichments in the gastrocnemius, which correlated with skeletal muscle responses from a published exercise study in humans. We uncovered sex-consistent post-translational modifications, including decreased oxidation of MYH2 and deacetylation of the {beta}-oxidation enzyme HADHA. Pathway enrichment analyses revealed sex-specific remodeling across the acetylome, redox proteome, and phosphoproteome; females decreased mitochondrial protein cysteine oxidation and increased mitochondrial cristae proteins, indicative of enhanced redox buffering and mitochondrial efficiency. Despite decreases in cysteine oxidation of key mitochondrial proteins, females displayed increases in the cysteine oxidation of proteins involved in glucose catabolism relative to males after 8 weeks of training, suggestive of sex-biased subcellular reactive oxygen species generation. Males demonstrated earlier induction of mitochondrial transcripts and predicted activation of mTOR. Although the increase in mitochondrial protein abundance was more modest in males, there was greater oxidation of mitochondrial proteins in response to training compared to females. ConclusionsThis work shows a large portion of the adaptive response to endurance training in skeletal muscle is shared between females and males, while there are distinct and nuanced sex-specific adaptations that are evident, particularly at the level of post-translational regulation.

physiology↗

Effects of Ambient Temperature During Pregnancy on Newborn Birthweight

This study evaluates the association between ambient temperature exposure during pregnancy and newborn birthweight, using a penalized generalized additive model (GAM) framework with distributed lag non-linear models (DLNM) to identify sensitive windows of exposure. The analysis includes 238 participants from the SHIP study with complete temperature exposure and birthweight data. Weekly maximum temperatures during pregnancy were estimated using Daymet data, and the impact of temperature on birthweight was assessed, adjusting for maternal age, pre-pregnancy BMI, gestational age, race, smoking, diabetes status, and infant biological sex. The model incorporated a crossbasis function for temperature exposure across 42 gestational weeks and allowed penalization for smoother, data-driven lag estimation. Results from the combined-sex model indicated that higher ambient temperatures during the third trimester, particularly in the final weeks of pregnancy, were associated with increased birthweight. Stratified analyses suggested that this association was more pronounced in male infants. These findings highlight the importance of considering prenatal temperature exposures and timing when evaluating determinants of newborn health.

developmental biology↗

Cysteine S-acetylation is a post-translational modification involved in metabolic regulation

Cysteine is a reactive amino acid central to the catalytic activities of many enzymes. It is also a common target of post-translational modifications (PTMs), such as palmitoylation. This long-chain acyl PTM can modify cysteine residues and induce changes in protein subcellular localization. We hypothesized that cysteine could also be modified by short-chain acyl groups, such as cysteine S-acetylation. To test this, we developed sample preparation and non-targeted mass spectrometry protocols to analyze the mouse liver proteome for cysteine acetylation. Our findings revealed hundreds of sites of cysteine acetylation across multiple tissue types, revealing a previously uncharacterized cysteine acetylome. Cysteine acetylation shows a marked cytoplasmic subcellular localization signature, with tissue-specific acetylome patterns and specific changes upon metabolic stress. This study uncovers a novel aspect of cysteine biochemistry, highlighting short-chain modifications alongside known long-chain acyl PTMs. These findings enrich our understanding of the landscape of acyl modifications and suggest new research directions in enzyme activity regulation and cellular signaling in metabolism.

biochemistry↗

Multi-omic rejuvenation and lifespan extension upon exposure to youthful circulation

Heterochronic parabiosis (HPB) is known for its functional rejuvenation effects across several mouse tissues. However, its impact on the biological age of organisms and their long-term health remains unknown. Here, we performed extended (3-month) HPB, followed by a 2-month detachment period of anastomosed pairs. Old detached mice exhibited improved physiological parameters and lived longer than control isochronic mice. HPB drastically reduced the biological age of blood and liver based on epigenetic analyses across several clock models on two independent platforms; remarkably, this rejuvenation effect persisted even after 2 months of detachment. Transcriptomic and epigenomic profiles of anastomosed mice showed an intermediate phenotype between old and young, suggesting a comprehensive multi-omic rejuvenation effect. In addition, old HPB mice showed transcriptome changes opposite to aging, but akin to several lifespan-extending interventions. Altogether, we reveal that long-term HPB can decrease the biological age of mice, in part through long-lasting epigenetic and transcriptome remodeling, culminating in the extension of lifespan and healthspan.

cell biology↗