ABSTRACT
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.
Subject(s)
Cystinyl Aminopeptidase/genetics , DNA-Binding Proteins/metabolism , Transcription Factors/metabolism , Trophoblasts/cytology , Trophoblasts/metabolism , Base Sequence , Cell Differentiation , Cell Line , Colforsin/pharmacology , DNA, Complementary/genetics , DNA-Binding Proteins/deficiency , DNA-Binding Proteins/genetics , Female , Gene Expression Regulation, Enzymologic , Humans , Immunohistochemistry , Luciferases/genetics , Models, Biological , Pregnancy , RNA, Messenger/genetics , RNA, Messenger/metabolism , Transcription Factor AP-2 , Transcription Factors/deficiency , Transcription Factors/geneticsABSTRACT
BACKGROUND: Cerebral circulatory changes in preeclampsia are unclear. We studied the changes in intracranial blood flow volume using a new color Doppler ultrasonographic assessment in a preeclamptic woman with photophobia. CASE: A 39-year-old preeclamptic primigravida was admitted and delivered by cesarean at 36 weeks' gestation. She developed bilateral photophobia with blood pressure elevation at 2 days postpartum. Blood flow volume index [mean velocity x pid(2)/4] (d = luminal diameter at systolic phase) was established. The sum of blood flow volume indexes of the bilateral internal carotid arteries and vertebral arteries increased at the onset of photophobia and blood pressure elevation. The blood flow volume index increased above 120 mm Hg of mean arterial blood pressure. CONCLUSION: These data represent the increased cerebral hemodynamic changes in preeclampsia with photophobia.
Subject(s)
Cerebrovascular Circulation , Photophobia/etiology , Postpartum Period , Pre-Eclampsia/complications , Adult , Carotid Arteries/diagnostic imaging , Female , Hemodynamics , Humans , Photophobia/physiopathology , Pre-Eclampsia/physiopathology , Pregnancy , Ultrasonography , Vertebral Artery/diagnostic imagingABSTRACT
In addition to prostaglandins, inflammatory cytokines induce uterine contraction via oxytocin (OT). Placental leucine aminopeptidase (P-LAP), an oxytocinase that is identical to cystine aminopeptidase, destroys OT activity. Patients with spontaneous preterm delivery have higher concentrations of inflammatory cytokines and lower P-LAP activities than those with normal delivery. In addition, the P-LAP promoter region contains putative binding sites for cytokine-induced transcription factors. We therefore postulated that inflammatory cytokines suppress P-LAP expression and examined this notion using BeWo choriocarcinoma cells cultured in the presence of cytokines. However, interleukin-1beta (IL-1beta) increased P-LAP activity in a time- and dose-dependent manner. Furthermore, Western blot analysis showed a dose-dependent increase of P-LAP proteins. We also detected IL-1 type I receptor mRNA in BeWo cells by RT-PCR. Semi-quantitative RT-PCR and Southern blot analysis showed that IL-1beta also increased P-LAP mRNA, which was abrogated by prior exposure to cycloheximide. Luciferase assays did not reveal any regulatory regions that could explain IL-1beta-induced P-LAP mRNA accumulation within 1.1 kb upstream of the P-LAP gene. Immunohistochemical analysis of human placenta with chorioamnionitis demonstrated prominent P-LAP staining at sites of abundant inflammatory cell infiltration. These findings indicated that prolonged exposure to IL-1beta induces P-LAP in the trophoblasts, possibly via other de-novo protein synthesis, which contradicted our initial hypothesis.
