Hypoxia-Inducible Factor 1 Is an Inductor of Transcription Factor Activating Protein 2 Epsilon Expression during Chondrogenic Differentiation

Figure 5

Upregulation of AP-2ε mRNA expression in response to hypoxia. (a) mMSC were cultured at hypoxia (1% O₂) or normoxia (21% O₂) for 24 h. After that, mRNA expression was analyzed via qRT-PCR. Compared to the control, a significant upregulation of AP-2ε (I) as well as Angptl4 (II) and Sox9 (IV) expression in cells incubated at 1% O₂ was detected. Expression of Col2a1 (III) and Acan (IV) also tended to be enhanced while MIA/CD-RAP (V) was even slightly downregulated. (b) HIF1α protein accumulation due to hypoxia was confirmed by western blot analysis. Numbers indicate densitometric measurement of the intensity of the HIF1α specific band (labeled) (data are given as means ± SEM; ns, not significant; ; ).

(a)

(b)