FIG. 1.

Gene expression patterns of adipogenic markers and cell cycle regulators during adipogenic differentiation. (A) Expression of PPARγ, CDC6, CCND1, Cdk1, Cdk4, CCNA2, CCND3, PLK2, and FBX05 were examined at 12, 24, 36, 48, 72, and 96 h after initial treatment in eight different treatment conditions, CM, DEX alone at 0.2 or 1.0 μM, IBMX (0.45 mM)+DEX (0.2 μM), AIM with 0.2 μM DEX or with 1.0 μM DEX, and OIM with 0.2 or 1.0 μM DEX. Expression of C/EBPα was examined in CM, DEX, IBMX+DEX, and AIM at 12, 24, 36, and 72 h after treatment initiation, as well as at 7 and 18 days postinitiation. PPARγ and C/EBPα were both upregulated by DEX, DEX+IBMX, and AIM starting at 24 h after initial media treatment, followed by a greater induction in IBMX+DEX or AIM at 72 h after treatment initiation. Expression of all cell cycle regulators was downregulated in IBMX+DEX and AIM relative to its expression in CM at 48, 72, and 96 h after treatment initiation. Expression of cell cycle genes was normalized to those of HSP90, a housekeeping gene used as internal loading control, and set relative to its level in CM (100%) at each time point. *Expression level was deemed undetectable in IBMX+DEX and AIM samples; ^#sample was missing. (B) Agrose gel images of RT-PCR products for HSP90, PPARγ, CCND1, Cdk1, and Cdk4, whose expression was examined at the selected time points after treatment initiation in eight treatment media conditions as described in (A) (n = 2). AIM, adipogenic inducing media; C/EBPα, CCAAT/enhancer binding protein alpha; CM, control growth media; DEX, dexamethasone; IBMX, 3-Isobutyl-1-methylxanthine; PPARγ, peroxisome proliferator-activated receptor gamma; RT-PCR, reverse transcription–polymerase chain reaction. Color images available online at www.liebertpub.com/scd