A New Preadipocyte Cell Line, AP-18, Established from Adult Mouse Adipose Tissue

Abstract

Establishing preadipocyte cell lines from mature adipose tissues could help lead to a better understanding of adipogenesis. We have established a unique preadipocyte cell line, AP-18, derived from the subepidermal layer of ear skin from an adult C3H/HeM mouse. AP-18 cells exhibit fibroblast-like morphology, slow growth, and contact inhibition. The doubling time of AP-18 cells is 50-60 h, which is about 2-fold longer than that of well-known 3T3-L1 cells derived from mouse embryos. A small population of AP-18 cells spontaneously differentiates into adipocytes by 8 days after confluence, as judged by the accumulation of triglyceride droplets. Treatment of confluent AP-18 preadipocytes with adipogenic agents, containing dexamethasone, 3-methyl-1-isobutylxanthine, and insulin, increased triglyceride contents about 5-fold compared to the contents in untreated cells. We also analyzed mRNA expression profiles for key transcription factors involved in adipocyte differentiation, peroxisome proliferator-activated receptor (PPAR)γ and the CCAAT/enhancer binding protein (C/EBP) family, and for differentiation markers, aP2, adipocyte-specific fatty acid-binding protein and adipsin, adipocyte-specific serine protease. AP-18 preadipocytes express mRNAs for C/EBPβ , C/EBPα , PPARγ , and aP2 before differentiation, but not adipsin mRNA. Expression of aP2 mRNA was increased in fully differentiated AP-18 cells. Likewise, expression of adipsin mRNA was increased after induced differentiation of AP-18 cells and reached the highest level in fully differentiated adipocytes. Thus, differentiation of AP-18 cells is associated with the increased expression of aP2 and adipsin mRNAs. The newly established AP-18 cell line provides a useful model for investigating adipocyte differentiation and adipogenesis.preadipocyte; mouse; proliferation; differentiation; adipogenesis © 2005 Tohoku University Medical PressThe first cell lines capable of differentiating into adipocytes were derived from the established murine 3T3 cell line. These lines, 3T3-L1 and 3T3-F442A, were derived from immortalized embryonic fibroblast cells of mesenchymal origin and are morphologically indistinguishable from fibroblasts (Green and Meuth 1974; Kehinde 1975, 1976). Other preadipocyte cell lines have also been studied, including Ob1771 and HGFu (Negrel et al. 1978;Forest et al. 1983).

In vitro expansion and differentiation of fresh and revitalized adult canine bone marrow-derived and adipose tissue-derived stromal cells

“…Decreasing cell doubling numbers with increasing passages suggest that canine MSCs from early passages may have greater potential for therapeutic use. The overall ASC DT in this study (around 2.5 days) is similar to that of human infrapatellar fat pad cells (2.0–2.5 days) (Dragoo et al, 2003), equine ASCs (2.0 days) (Vidal et al, 2007), and adult murine preadipocytes (2.0–2.5 days) (Doi et al, 2005). …”

Characterization of Equine Adipose Tissue‐Derived Stromal Cells: Adipogenic and Osteogenic Capacity and Comparison with Bone Marrow‐Derived Mesenchymal Stromal Cells

“…Cell doubling time of $ 2 days for equine ASCs was more rapid than the $ 4 days required by human ASCs 5 cultured under similar conditions in our laboratory but was comparable with that of a recently established adult murine preadipocyte cell line (2-2.5 days). 23 This suggests that there is some variability in ASC DT among species. This interspecies variation may be the result of different culture conditions and medium composition.…”

Characterization of a novel murine preadipocyte line, AP‐18, isolated from subcutaneous tissue: Analysis of adipocyte‐related gene expressions

“…Adipocytokine genes during AP‐18 cell differentiation were also analysed. In contrast to LM cells, AP‐18 cells expressed all of the genes (Pref‐1, LPL, C/EBPβ, C/EBPδ, RXRα, C/EBPα, PPARγ, RXRα, aP2, GLUT4, SCD1, UCP2, UCP3, TNFα, resistin, leptin, adiponectin and PAI‐1) except UCP1 (Dulloo and Samec, 2001) through the whole differentiation process. This indicates that AP‐18 cells were derived from WAT rather than BAT (brown adipose tissue).…”

“…Previously, a murine adipocyte line designated AP-18 has been established (Doi et al, 2005). AP-18 cells differ from the established preadipocytes such as 3T3-L1 and Ob17 in terms of the cell origin and condition for inducing differentiation.…”