Inhibition of ZFP36, ZFP36L1, and ZFP36L2 gene expression in cultured keratinocytes. HaCaT keratinocytes were transfected with specific siRNAs directed against ZFP36or ZFP36L1, an unspecific (“scrambled”) negative control, or left untreated. (A) To assess the efficiency of the transfection procedure, the cells were first transfected with aFITC-labelled “scrambled” siRNA and analyzed by FACS sorting. (B) After inhibition of expression of ZFP36 or ZFP36L1 via siRNA transfection, cells were rendered quiescentby serum starvation and subsequently scratch-wounded. Expression of ZFP36 and ZFP36L1 was analyzed by qPCR. Data are expressed as means +/− SD (n = 2). *: p < 0.05; **:p < 0.01. (C) ZFP36L1 expression was also analyzed by Western blot 24 h after transfection (without scratching). GAPDH levels were assessed as a control for equal loading.