Figure 4.

TNF-α down-regulates periplakin expression in HMEC-1, HUVEC and HSVEC. (A) Total RNA from HMEC-1 lines and primary HUVEC and HSVEC stimulated with TNF-α for 16 h was used for cDNA preparation and RT–PCR analysis. (B) Time course of periplakin mRNA down-regulation in response to TNF-α. HMEC-1 stably expressing the empty vector or transdominant IκBα, or HUVEC were stimulated with TNF-α for the indicated intervals, total RNA was analyzed by RT–PCR. (C) Expression level of periplakin was analyzed after TNF-α stimulation in the presence of cycloheximide. Confluent cells were pre-incubated with vehicle or cycloheximide (CHX) for 1 h and then treated with TNF-α or medium for 8 h. (D) Western blot analysis for periplakin (195 kDa). Parental or TD-IκBα transduced HMEC-1 were stimulated with TNF-α for 16 h and whole protein extracts were probed with a periplakin-specific $\text{antibod}\stackrel{\sim }{\text{y}}$. RelA/p65 was used as loading control.