adipose tissue, the ECM undergoes constant remodeling to allow changes in cell shape (from fibroblastic to spherical) in a process called adipogenesis during the switch between the proliferative and differentiated states. Although the transcriptional program of this process has been revealed in great detail, the microenvironmental
factors triggering and controlling the cell differentiation process are not. For instance, has been previously shown that MMP-14 deficiency does not interfere with adipogenesis under conventional two dimensions (2D) culture in vitro. However, its loss inhibits completely the differentiation process when tested within a three-dimensional (3D) collagen gel. Therefore, this protein represents an ideal model for establishing a new cell culture technology. This however is not a simple task due to the fact that our standard 2D cell cultures are not closely enough reflecting ECMs found under in vivo conditions. To overcome the disadvantages of current cell assay platforms for screening ECM remodeling processes in general the first goal was to investigate EMC remodeling in 3D tissue model system. To approach this complex task we first established the protein analytics in standard 2D cell culture technology and then transfered the knowledge to the 3D approach by using a microfluidic large-scale integration (mLSI) chip platform to integrate the steps of formation a 3D spheroid cell culture, long-term cultivation of stem cell spheroids, differentiation, and protein analytics. Additionally to the known behavior of MMP14 we investigated in detail MMP-2, which is activated by MMP-14 but its precise function during the ECM remodeling process in 2 and 3D cell cultures is unknown. Upon measuring quantitatively the protein expression pattern of MMP-14 and MMP-2 together with collagens an fibronectin in 2D standard cell cultures, our results confirmed that MMPs play a central role during early stages (from 0 to 6 days) of white adipocyte differentiation. PLA results showed that MMP-2 has no direct impact on the expression levels of MMP-14 and FN. However, FN regulation is more dependent on the expression of MMP-14 as observed with siRNA silencing strategy.