Ijeoma Azonobi | PubMed Health

PubMed2003

Prostacylin receptor activation inhibits proliferation of aortic smooth muscle cells by regulating cAMP response element-binding protein- and pocket protein-dependent cyclin a gene expression.

The prostanoid prostacyclin (PGI2) inhibits aortic smooth muscle cell proliferation by blocking cell cycle progression from G1-to S-phase. However, the mechanism of this inhibition is poorly understood. We report here that the PGI2 mimetic, cicaprost, inhibits the induction of cyclin A and activation of the cyclin A promoter in primary and established rodent aortic smooth muscle cells. The inhibition of cyclin A gene expression is associated with a block in cyclin E-cdk2 activity and phosphorylation of both the retinoblastoma protein and p107. Inactivation of pocket proteins with human papilloma virus protein E7 partially, but not completely, restored cyclin A promoter activity in cicaprost-treated cells. Complementary studies showed that occupancy of the cAMP response element (CRE) is required for efficient activation of the cyclin A promoter in aortic smooth muscle cells, that the CRE is primarily occupied by the CRE-binding protein (CREB) and phospho-CREB, and that cicaprost blocks the binding of CREB and phospho-CREB to the cyclin A promoter CRE. Treatment with pertussis toxin reversed the inhibitory effects of cicaprost on CRE occupancy, cyclin E-cdk2 activity, and S phase entry, suggesting the involvement of Gi signaling in cicaprost action. We conclude that PGI2 inhibits proliferation of aortic smooth muscle cells by coordinately blocking CRE- and pocket protein-dependent cyclin A gene expression.

Aorta↗

PubMedDate not supplied

Late-onset postpartum eclampsia.

Eclampsia typically occurs in the antepartum or intrapartum period. Late-onset postpartum eclampsia is a controversial topic, which recently has been accepted as a true phenomenon. Late-onset postpartum eclampsia is a rare occurrence, although literature suggests that it is an increasing phenomenon. In this case study, an essentially healthy primigravida developed eclampsia 7 days postpartum after an unremarkable antepartum and intrapartum course. Because significant morbidity and mortality are associated with this disorder, it is imperative that efforts be made to prevent its occurrence. We recommend including patient education about the prodromal symptoms of late-onset postpartum eclampsia, including headache, visual changes, and abdominal pain at the time of hospital discharge.

Adult↗