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Updated: Apr 4, 2026
Differentiation and Imaging of Brown Adipocytes from the Stromal Vascular Fraction of Interscapular Adipose Tissue from Newborn Mice
Published on: February 3, 2023
In vitro differentiation of mouse brown preadipocytes is enhanced by IGFBP-3 expression and reduced by IGFBP-3
K Hoa Nguyen1, Suresh Mishra1, B L Grégoire Nyomba1
1Department of Internal Medicine, University of Manitoba, Winnipeg, Canada.
Objective:
White adipocyte metabolism is regulated by insulin-like growth factor-binding protein (IGFBP)-3, but its effect on brown adipocytes is not known. This study investigated whether IGFBP-3 influences the proliferation and differentiation of brown preadipocytes in primary culture.
Methods:
In vitro growth and differentiation of brown preadipocytes from wild-type mice, transgenic mice overexpressing human IGFBP-3 (PGKBP3), or its non-IGF-binding Gly56/Gly80/Gly81-mutant (PGKmutBP3), and wild-type brown preadipocytes transfected with IGFBP-3 siRNA were studied by us. In addition to IGF-I and IGFBP-3 expression, brown preadipocyte growth and differentiation were assessed by antiproliferating cell nuclear antigen, oil red O, brown fat gene expression, and phosphorylation states of Akt and ERK.
Results:
Akt phosphorylation and IGF-I expression were paralleled by initial growth and differentiation and were slower for PGKBP3 brown preadipocytes than PGKmutBP3 and wild-type preadipocytes. Terminal adipocyte differentiation as assessed by lipid accumulation coincided with ERK inhibition and was greatest in PGKmutBP3 cells, followed by PGKBP3 cells and then wild-type cells, whereas adipocyte differentiation was poor after IGFBP-3 siRNA treatment. Thermogenic genes were increased by IGFBP-3 overexpression, but lower in differentiated PGKmutBP3 than PGKBP3 cells.
Conclusions:
Brown adipocyte growth and differentiation in vitro were affected by the manipulation of IGFBP-3 expression, suggesting that IGFBP-3 is a factor regulating brown adipocyte fate.
