Animal models of haploinsufficiency revealed the isoform-specific role of GSK-3 in HFD-induced obesity and glucose intolerance.

Autor: Gupte M; Department of Biology, Austin Peay State University, Clarksville, Tennessee, United States., Umbarkar P; Division of Cardiovascular Diseases, U.A.B. | University of Alabama at Birmingham, Birmingham, Alabama, United States., Lemon J; Department of Biology, Austin Peay State University, Clarksville, Tennessee, United States., Tousif S; Division of Cardiovascular Diseases, U.A.B. | University of Alabama at Birmingham, Birmingham, Alabama, United States., Lal H; Division of Cardiovascular Diseases, U.A.B. | University of Alabama at Birmingham, Birmingham, Alabama, United States.
Jazyk: angličtina
Zdroj: American journal of physiology. Cell physiology [Am J Physiol Cell Physiol] 2024 Dec 01; Vol. 327 (6), pp. C1349-C1358. Date of Electronic Publication: 2024 Sep 30.
DOI: 10.1152/ajpcell.00552.2024
Abstrakt: Glycogen synthase kinase 3 (GSK-3), a serine-threonine kinase with two isoforms (α and β) is implicated in the pathogenesis of type 2 diabetes mellitus (T2D). Recently, we reported the isoform-specific role of GSK-3 in T2D using homozygous GSK-3α/β knockout mice. Although the homozygous inhibition models are idealistic in a preclinical setting, they do not mimic the inhibition seen with pharmacological agents. Hence, in this study, we sought to investigate the dose-response effect of GSK-3α/β inhibition in the pathogenesis of obesity-induced T2D. Specifically, to gain insight into the dose-response effect of GSK-3 isoforms in T2D, we generated tamoxifen-inducible global GSK-3α/β heterozygous mice. GSK-3α/β heterozygous and control mice were fed a high-fat diet (HFD) for 16 wk. At baseline, the body weight and glucose tolerance of GSK-3α heterozygous and controls were comparable. In contrast, at baseline, a modest but significantly higher body weight (higher lean mass) was seen in GSK-3β heterozygous compared with controls. Post-HFD, GSK-3α heterozygous and controls displayed a comparable phenotype. However, GSK-3β heterozygous were significantly protected against obesity-induced glucose intolerance. Interestingly, the improved glucose tolerance in GSK-3β heterozygous animals was dampened with chronic HFD-feeding, likely due to significantly higher fat mass and lower lean mass in the GSK-3β animals. These findings suggest that GSK-3β is the dominant isoform in glucose metabolism. However, to avail the metabolic benefits of GSK-3β inhibition, it is critical to maintain a healthy weight. NEW & NOTEWORTHY The precise isoform-specific role of GSK-3 in obesity-induced glucose intolerance is unclear. To overcome the limitations of pharmacological GSK-3 inhibitors (not isoform-specific) and tissue-specific genetic models, in the present study, we created novel inducible heterozygous mouse models of GSK-3 inhibition that allowed us to delete the gene globally in an isoform-specific and temporal manner to determine the isoform-specific role of GSK-3 in obesity-induced glucose intolerance.
Databáze: MEDLINE