Secretome analysis of hypoxia-induced 3T3-L1 adipocytes uncovers novel proteins potentially involved in obesity

ABSTRACT: In the obese state, as adipose tissue expands, adipocytes become hypoxic and dysfunctional, leading to changes in the pattern of secreted proteins. To better understand the role of hypoxia in the mechanisms linked to obesity, we comparatively analyzed the secretome of differentiated 3T3-L1 adipocytes exposed to normoxia or hypoxia for 24 h. Proteins secreted into the culture media were precipitated using trichloroacetic acid and then digested by trypsin. Peptides were labeled by dimethyl labeling and analyzed by reversed phase nanoscale liquid chromatography coupled to a quadrupole Orbitrap mass spectrometer. Among factors downregulated in hypoxic conditions, we identified Decorin, a member of the leucine-rich proteoglycan family, Tissue Inhibitor of Metalloproteinase-2, Thrombospondin 1 and 2, all multifunctional proteins involved in extracellular matrix (ECM) homeostasis, and angiogenesis. Most findings were confirmed by expression studies of the relative genes in parallel experiments in vitro, in differentiated 3T3-L1 adipocytes, and in vivo, in fat tissues from obese vs. lean rats. Our observations are compatible with the concept that hypoxia may be an early trigger for ECM remodeling and angiogenesis in adipose tissue.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Cell Culture

SUBMITTER: Mariaconcetta Varano  

LAB HEAD: Antonio Brunetti

PROVIDER: PXD006820 | Pride | 2018-02-27

REPOSITORIES: Pride