title: Extracellular matrix with the rigidity of adipose tissue helps 3T3-L1 adipocytes maintain insulin responsiveness.
abstract: Despite the popularity of 3T3-L1 adipocytes as a model system of adipocytes in vivo, they do not carry all of the cellular functions of adipocytes in vivo. In this study, we investigated the effect of extracellular matrix (ECM) rigidity on insulin signal transduction in 3T3-L1 adipocytes. On 250 Pa polyacrylamide gel (soft gel) laminated with a mixture of collagen type 1 and fibronectin, whose rigidity matches that of adipose tissue, expression of the insulin receptor, IRS-1 and AKT was upregulated and their insulin-stimulated phosphorylation was enhanced. Furthermore, the expression of GLUT1 was downregulated, whereas the expression of GLUT4 was unaffected as ECM rigidity decreased. Insulin-stimulated GLUT4 recruitment to the plasma membrane was significantly enhanced in cells seeded on soft gel. These results suggest that adjusting the ECM rigidity to that of adipose tissue augments insulin signaling in 3T3-L1 adipocytes and enhances insulin-stimulated GLUT4 recruitment to the plasma membrane.
authors.affiliation: Department of Nutrition and Metabolism, Institute of Health Biosciences, the University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Qinkai
authors.initials: Q
authors.lastname: Li
authors.forename: Toshio
authors.initials: T
authors.lastname: Hosaka
authors.forename: Bayasglan
authors.initials: B
authors.lastname: Jambaldorj
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nakaya
authors.forename: Makoto
authors.initials: M
authors.lastname: Funaki
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D055592:Biophysical Phenomena; D005109:Extracellular Matrix / Q000378:metabolism*; D051272:Glucose Transporter Type 1 / Q000378:metabolism; D051275:Glucose Transporter Type 4 / Q000235:genetics / Q000378:metabolism; D007328:Insulin / Q000378:metabolism* / Q000494:pharmacology; D051379:Mice; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection
chemical_list: D051272:Glucose Transporter Type 1; D051275:Glucose Transporter Type 4; D007328:Insulin; D011993:Recombinant Fusion Proteins; C495678:Slc2a1 protein, mouse; C495693:Slc2a4 protein, mouse