Wagner, A.; Lautaoja-Kivipelto, J.; Pehkonen, K.; Hassinen, A.; Kuusela, M.; Röttger, L.; Herbers, E.; Ioannidou, A.; Mädler, S.; Rothenaigner, I.; Srinivasan, S.; Laasonen, S.; Rahman, M. T.; Elomaa, P.; Kortetjärvi, S.; Olsson, A.; Ukkola, O.; Hadian, K.; Mann, M.; Peltoniemi, H.; Pietiläinen, K. H.; Klingenspor, M.; Virtanen, K. A.; Hagberg, C. E.; Pirinen, E.

Mitochondrial abnormalities drive subcutaneous white adipose tissue dysfunction in obesity, leading to metabolic complications. A key challenge in obesity research is the lack of in vitro models to study human adipocyte mitochondria. Here, we establish a human subcutaneous adipocyte spheroid model to characterize mitochondrial metabolism under obesity-relevant conditions and drug exposure. Human preadipocyte spheroids were differentiated in ultra-low attachment plates for 3 weeks in media free of thiazolidinediones. The differentiated adipocyte spheroids showed increased lipid accumulation, adipogenic gene expression, mitochondrial respiration and adiponectin secretion, and a proper response to hormonal stimulation. Lipid mixture administration during differentiation induced metabolic disturbances including mitochondrial respiration failure associated with increased mitochondrial biogenesis. Post-differentiation treatment with rosiglitazone, a peroxisome proliferator-activated receptor gamma agonist, improved mitochondrial bioenergetics and adiponectin secretion in lipid mixture-administered adipocyte spheroids.