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.