Adipogenesis of 3T3L1 cells subjected to tensile deformations under various glucose concentrations

Glucose transport in fat cells results in accumulation of triglycerides in lipid droplets and is regulated by insulin. When a fat tissue becomes insulin-resistant, glucose transport into the cells is impaired and results in Type 2 diabetes. The lipid droplets accumulation is part of the adipogenesis differentiation and metabolism. In the current study, we monitored the adipogenesis of 3T3-L1 cultured cells in high and low glucose concentrations, while the cells were exposed to different substrate rigidity and tensile deformation. Phase contrast images were taken along the adipogenesis process and were analyzed by a new MATLAB image processing algorithm, based on a previous code written in our group (Levy in Annals of biomedical engineering 40:1052–1060, 2012). The new algorithm follows cell differentiation (cell size and morphology and nucleus size) and lipid accumulation (number of lipid droplets per cell and their radius). Complementary, we analyzed by immunofluorescence (IF) the molecular expression of PPARγ, a transcription factor, along with DNA staining by DAPI and Lamin A/C for the nucleus organization. The results indicate that high glucose concentration and substrate tensile strains delivered to adipocytes accelerate their lipid production. In addition, the cell and nucleus area and cell morphology change during the differentiation process.