| Title: |
Common and distinct roles of AMPKγ isoforms in small-molecule activator-stimulated glucose uptake in mouse skeletal muscle |
| Authors: |
Biswas, Dipsikha; Espino-Gonzalez, Ever; Ahwazi, Danial; Freemantle, Jordana B.; Jomard, Charline; Brorson, Jonas; Schou, Agnete N.; Farup, Jean; Gondin, Julien; Just, Jesper; Foretz, Marc; Treebak, Jonas T.; Agerholm, Marianne; Sakamoto, Kei |
| Source: |
Biswas , D , Espino-Gonzalez , E , Ahwazi , D , Freemantle , J B , Jomard , C , Brorson , J , Schou , A N , Farup , J , Gondin , J , Just , J , Foretz , M , Treebak , J T , Agerholm , M & Sakamoto , K 2025 ' Common and distinct roles of AMPKγ isoforms in small-molecule activator-stimulated glucose uptake in mouse skeletal muscle ' bioRxiv . https://doi.org/10.1101/2025.09.26.678768 |
| Publisher Information: |
bioRxiv |
| Publication Year: |
2025 |
| Collection: |
University of Copenhagen: Research / Forskning ved Københavns Universitet |
| Description: |
Objective Small-molecule activators targeting the allosteric drug and metabolite (ADaM) site of AMPK enhance insulin-independent glucose uptake in skeletal muscle and lower glucose in preclinical models of hyperglycemia. The regulatory AMPKγ subunit plays a central role in energy sensing. While the skeletal muscle-selective γ3 isoform is essential for AMP/ZMP-induced glucose uptake, it is dispensable for ADaM site-binding activators. We hypothesized that the predominant γ1 isoform is required for ADaM site activator-stimulated glucose uptake in skeletal muscle. Methods Single-nucleus RNA sequencing (snRNA-seq) was performed on mouse and human skeletal muscle mapping AMPK subunit isoform distribution across resident cell types. To determine γ isoform-specific requirements for activator-stimulated glucose uptake, skeletal muscle-specific inducible AMPKγ1/γ3 double knockout (imγ1-/-/γ3-/-) and single knockout (imγ1⁻/⁻ and imγ3⁻/⁻) mice were generated. Ex vivo glucose uptake was measured following treatment with AICAR (AMP-mimetic) or MK-8722 (ADaM site activator), and in vivo MK-8722-induced blood glucose lowering was assessed. Results snRNA-seq revealed distinct AMPK isoform distribution: γ1 was ubiquitously expressed, whereas γ3 was enriched in glycolytic myofibers in both mouse and human skeletal muscle. Ex vivo, glucose uptake stimulated by either AICAR or MK-8722 was abolished in imγ1⁻/⁻/γ3⁻/⁻ muscle, and MK-8722-induced blood glucose lowering was significantly blunted in vivo. AICAR but not MK-8722-stimulated muscle glucose uptake was abolished in imγ3⁻/⁻, whereas both activators fully retained effects on glucose uptake and glucose lowering in imγ1⁻/⁻ mice. Conclusions While γ1 predominates in stabilizing the AMPKα2β2γ1 complex, it is dispensable for AMPK activator-stimulated glucose uptake in skeletal muscle, whether mediated via the nucleotide-binding or ADaM site. |
| Document Type: |
report |
| File Description: |
application/pdf |
| Language: |
English |
| DOI: |
10.1101/2025.09.26.678768 |
| Availability: |
https://researchprofiles.ku.dk/da/publications/adf7ebd3-9241-49a1-bba5-176769967afc; https://doi.org/10.1101/2025.09.26.678768; https://curis.ku.dk/ws/files/529238658/2025.09.26.678768v1.full.pdf |
| Rights: |
info:eu-repo/semantics/openAccess |
| Accession Number: |
edsbas.C2E1B190 |
| Database: |
BASE |