Annexin A3 as a negative regulator of adipocyte differentiation.
Annexin A3 is a protein belonging to the annexin family, and it is mainly present in cellular membranes as a phospholipid-binding protein that binds via the calcium ion. However, its physiological function remains to be clarified. We examined the expression of annexin A3 in mouse tissues and found for the first time that annexin A3 mRNA and its protein were expressed more strongly in adipose tissues than in other tissues. In adipose tissues, annexin A3-expressing cells were present in the stromal vascular fraction, and precisely identical to Pref-1-positive preadipocytes, Pref-1 being an epidermal growth factor repeat-containing transmembrane protein that inhibits adipogenesis. In 3T3-L1 cells, used as a model of adipogenesis, annexin A3 was down-regulated at an early phase of adipocyte differentiation, and this pattern paralleled that of Pref-1. Suppression of annexin A3 in these cells with siRNA caused elevation of the PPARγ2 mRNA level and lipid droplet accumulation. In conclusion, our data suggest that annexin A3 is a negative regulator of adipocyte differentiation.
Department of Chemistry and Life Science, Nihon University College of Bioresource Sciences, Kanagawa 252-0880, Japan.
Takenori
T
Watanabe
Yoshimasa
Y
Ito
Asuka
A
Sato
Takashi
T
Hosono
Shingo
S
Niimi
Toyohiko
T
Ariga
Taiichiro
T
Seki
D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology* / Q000378:metabolism*; D050156:Adipogenesis; D000818:Animals; D017318:Annexin A3 / Q000378:metabolism*; D002478:Cells, Cultured; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL
D017318:Annexin A3