Biology subjects

Houmard, J. A.

Publications and source records attributed to Houmard, J. A..

4 recordsLinked to original sources

bioRxiv2026

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↗

bioRxiv2026

A full-length single nuclei transcriptomic atlas of human skeletal muscle insulin resistance

Skeletal muscle (SkM) insulin resistance is a central defect in T2D, yet cell specific molecular determinants remain incompletely understood. Here, we integrate full-length single-nucleus transcriptomics with gold-standard stable isotope-labeled hyperinsulinemic-euglycemic clamps to generate a nucleus-resolved transcriptomic atlas of SkM insulin resistance. We identify previously unrecognized myonuclear populations whose proportions associate with insulin sensitivity across independent cohorts, revealing MYH7B+ myonuclei are metabolically favorable over EGF+ myonuclei. Modeling transcriptional variation against tracer-derived glucose disposal uncovers highly nucleus-specific molecular programs that are obscured when using surrogate fasting indices. Mechanistically, we identify zinc transporter ZIP14 as a positive regulator of insulin-stimulated glucose uptake and implicate EGF signaling in impaired branched-chain amino acid catabolism and inflammatory cross-talk within the SkM niche. Together, these findings redefine SkM insulin resistance as a multicellular, nucleus-resolved process and highlight new cell type specific targets for metabolic intervention.

molecular biology↗

bioRxiv2021

Type 2 Diabetes Modifies Skeletal Muscle Gene Expression Response to Gastric Bypass Surgery

Roux-en-Y gastric bypass (RYGB) is an effective treatment for type 2 diabetes mellitus (T2DM) which can result in remission of clinical symptoms, yet mechanisms for improved skeletal muscle health are poorly understood. We sought to define the impact of existing T2DM on RYGB-induced muscle transcriptome changes. MethodsVastus lateralis biopsy transcriptomes were generated pre- and 1-yr post-RYGB in black adult females with (T2D; n = 5, age=51{+/-}6 yr, BMI=53.0{+/-}5.8 kg/m2) and without (CON; n = 7,43{+/-}6 yr,51.0{+/-}9.2 kg/m2) T2DM. Insulin, glucose, and HOMA-IR were measured in blood at the same time points. ANCOVA detected differentially expressed genes (p< 0.01, Fold change<|1.2|), which were used to identify enriched biological pathways. ResultsPre-RYGB, 95 probes were downregulated with T2D including subunits of mitochondrial complex I. Post-RYGB, the T2D group had normalized gene expression when compared to their non-diabetic counterparts with only 3 probes remaining significantly different. In the T2D, we identified 52 probes upregulated from pre- to post-RYGB, including NDFUB7 and NDFUA1. ConclusionBlack females with T2DM show extensive down regulation of genes across aerobic metabolism pathways prior to RYGB, which resolves 1 year post-RYGB and is related to improvements in clinical markers. These data support efficacy of RYGB for improving skeletal muscle health, especially in patients with T2DM.

molecular biology↗

bioRxiv2019

The Lands cycle modulates plasma membrane lipid organization and insulin sensitivity in skeletal muscle

Aberrant lipid metabolism promotes the development of skeletal muscle insulin resistance, but the exact identity of lipid-mediated mechanisms relevant to human obesity remains unclear. A comprehensive lipidomic analyses of primary myocytes from lean insulin-sensitive (LN) and obese insulin-resistant (OB) individuals revealed several species of lysophospholipids (lyso-PL) that were differentially-abundant. These changes coincided with greater expression of lysophosphatidylcholine acyltransferase 3 (LPCAT3), an enzyme involved in phospholipid transacylation (Lands cycle). Strikingly, mice with skeletal muscle-specific knockout of LPCAT3 (LPCAT3-MKO) exhibited greater muscle lyso-PC/PC, concomitant with greater insulin sensitivity in vivo and insulin-stimulated skeletal muscle glucose uptake ex vivo. Absence of LPCAT3 reduced phospholipid packing of the cellular membranes and increased plasma membrane lipid clustering, suggesting that LPCAT3 affects insulin receptor phosphorylation by modulating plasma membrane lipid organization. In conclusion, obesity accelerates the skeletal muscle Lands cycle, whose consequence might induce the disruption of plasma membrane organization that suppresses muscle insulin action.

physiology↗