Iwanaga Kumi, Nomura Seiji, Ito Tomomi, Ikoma Yoko, Yamamoto Eiko, Okada Mayumi, Itakura Atsuo, Kikkawa Fumitaka, Tsujimoto Masafumi, Mizutani Shigehiko
Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, 466-8550 Nagoya, Japan.
FEBS Lett. 2003 Sep 25;552(2-3):120-4. doi: 10.1016/s0014-5793(03)00897-4.
Placental leucine aminopeptidase (P-LAP) is located preferentially in syncytiotrophoblasts in human placenta. Here we investigated P-LAP expression and the regulatory mechanisms in BeWo choriocarcinoma cells with forskolin (FSK)-induced differentiation. Morphologically differentiated cells revealed enhanced P-LAP staining. FSK significantly increased P-LAP activity and mRNA. Deletion or mutation of activator protein-2 (AP-2) binding site in the footprint-3 (-216 to -172) of P-LAP promoter abrogated the stimulatory effects of FSK on luciferase activity of the construct -216/+49. In AP-2-deficient Hep-G2 cells, FSK failed to stimulate luciferase activity of the construct -216/+49. Among the isoforms, BeWo expressed AP-2alpha and AP-2gamma, while FSK increased only AP-2alpha. These results suggest differentiation-dependent P-LAP expression in trophoblasts, which involves increased AP-2alpha binding.
胎盘亮氨酸氨肽酶（P-LAP）优先定位于人胎盘的合体滋养层细胞中。在此，我们研究了福司可林（FSK）诱导分化的BeWo绒癌细胞中P-LAP的表达及调控机制。形态学上分化的细胞显示P-LAP染色增强。FSK显著增加P-LAP活性和mRNA水平。P-LAP启动子足迹-3（-216至-172）中激活蛋白-2（AP-）结合位点的缺失或突变消除了FSK对构建体-216/+49荧光素酶活性的刺激作用。在AP-2缺陷的Hep-G2细胞中，FSK未能刺激构建体-216/+49的荧光素酶活性。在这些亚型中，BeWo表达AP-2α和AP-2γ，而FSK仅增加AP-2α。这些结果表明滋养层细胞中存在依赖分化的P-LAP表达，这涉及AP-2α结合增加。
