Comprehensive Proteomic Profiling of Converted Adipocyte-like Cells from Normal Human Dermal Fibroblasts Using Data-Independent Acquisition Mass Spectrometry

Adipocytes play an important role in the regulation of systemic
energy homeostasis and are closely related to metabolic disorders,
such as type-2 diabetes and inflammatory bowel diseases. Particularly,
there is an increasing need for a human adipocyte model for studying
metabolic diseases and obesity. However, utilizing human primary adipocyte
culture and stem-cell-based models presents several practical limitations
due to their time-consuming nature, requirement for relatively intensive
labor, and high cost. Here, we applied direct conversion of normal
human dermal fibroblasts (NHDFs) into adipocyte-like cells using an
adipogenic cocktail containing 3-isobutyl-1-methylxanthine (IBMX),
dexamethasone, insulin, and rosiglitazone and confirmed prominent
lipid droplet accumulation in the converted cells. For profiling the
proteome changes in the converted cells, we conducted a comprehensive
quantitative proteome analysis of both the intracellular and extracellular
proteome fractions using data-independent acquisition mass spectrometry.
We observed that several proteins, which are known to be highly expressed
in adipocytes specifically, were dominantly increased in the converted
cells. In this study, we suggest that NHDFs can be converted into
adipocyte-like cells by an adipogenic cocktail and can serve as a
useful tool for studying human adipocytes and their metabolism.