Rizo-Roca 2024 Sci Transl Med
| Rizo-Roca D, GuimarΓ£es DSPSF, Pendergrast LA, Di Leo N, Chibalin AV, Maqdasy S, RydΓ©n M, NΓ€slund E, Zierath JR, Krook A (2024) Decreased mitochondrial creatine kinase 2 impairs skeletal muscle mitochondrial function independently of insulin in type 2 diabetes. Sci Transl Med 16:eado3022. https://doi.org/10.1126/scitranslmed.ado3022 |
Rizo-Roca David, Guimaraes Dimitrius Santiago PSF, Pendergrast Logan A, Di Leo Nicolas, Chibalin Alexander V, Maqdasy Salwan, Ryden Mikael, Naeslund Erik, Zierath Juleen R, Krook Anna (2024) Sci Transl Med
Abstract: Increased plasma creatine concentrations are associated with the risk of type 2 diabetes, but whether this alteration is associated with or causal for impairments in metabolism remains unexplored. Because skeletal muscle is the main disposal site of both creatine and glucose, we investigated the role of intramuscular creatine metabolism in the pathophysiology of insulin resistance in type 2 diabetes. In men with type 2 diabetes, plasma creatine concentrations were increased, and intramuscular phosphocreatine content was reduced. These alterations were coupled to reduced expression of sarcomeric mitochondrial creatine kinase 2 (CKMT2). In C57BL/6 mice fed a high-fat diet, neither supplementation with creatine for 2 weeks nor treatment with the creatine analog Ξ²-GPA for 1 week induced changes in glucose tolerance, suggesting that increased circulating creatine was associated with insulin resistance rather than causing it. In C2C12 myotubes, silencing Ckmt2 using small interfering RNA reduced mitochondrial respiration, membrane potential, and glucose oxidation. Electroporation-mediated overexpression of Ckmt2 in skeletal muscle of high-fat diet-fed male mice increased mitochondrial respiration, independent of creatine availability. Given that overexpression of Ckmt2 improved mitochondrial function, we explored whether exercise regulates CKMT2 expression. Analysis of public data revealed that CKMT2 content was up-regulated by exercise training in both humans and mice. We reveal a previously underappreciated role of CKMT2 in mitochondrial homeostasis beyond its function for creatine phosphorylation, independent of insulin action. Collectively, our data provide functional evidence for how CKMT2 mediates mitochondrial dysfunction associated with type 2 diabetes.
β’ Bioblast editor: Plangger M
Labels: MiParea: Respiration, Genetic knockout;overexpression
Pathology: Diabetes
Organism: Mouse Tissue;cell: Skeletal muscle Preparation: Permeabilized tissue, Intact cells
Regulation: PCr;Cr Coupling state: ET, LEAK, ROUTINE, OXPHOS Pathway: N, S, NS, ROX HRR: Oxygraph-2k
2024-10
