FK506 BINDING PROTEIN 52 MODULATED AP-1 FUNCTIONS IN HUMAN TROPHOBLAST CELLS

ERLEJMAN, AG; DE LEO SA.; GALIGNIANA, MB; CAMISAY MF.; FONTANA V; ERLEJMAN, AG; GALIGNIANA, MB; DE LEO SA.; CAMISAY MF.; FONTANA V

Puert Varas

Congreso; Latin American Society for Maternal Fetal Interaction and Placenta (SLIMP2017); 2017

Latin American Society for Maternal Fetal Interaction and Placenta

a)      FK506binding protein 52 (FKBP52) is a cochaperone that influences steroid receptorsfunction and has peptidylprolyl-isomerase (PPIase) activity. Reduced FKBP52protein has been detected in placentas from preeclampsia (PE), also it has beensuggested that c-fos is implicated in regulating invasive mechanism oftrophoblast in PE as well as in placentas from normal gestations. Objective:The aim of this work was to investigate the effect of FKBP52 on the transcriptionfactor activator protein 1 (AP-1) in trophoblast cells. Methods: BeWo were usedas in vitro choriocarcinoma model. Cells were transfected with wild type FKBPsor their putative PPIase mutants, and then, stimulated by miristic-acetatedphorbol ester 12-myristate 13-acetate (PMA). AP-1 signalling was evaluated byluciferase assays and Western blot, extracellular signal-regulated kinases 1and 2 (pERK1/2)/total ERK ratio along time (90 min). Interleukin 6 (IL-6)secretion was measured by ELISA, and matrix metalloproteinase 2 (MMP-2)proteolytic activity was determined by zymography. Results: After 30 min of PMAtreatment ERK1/2 acquired its maximum phosphorylation level. In the presence ofFKBP52 total ERK1/2 was unaltered, but pERK1/2 / total ERK1/2 remainedincreased along time (P<0.01, n = 6), and increased c-fos protein level (1.9± 0.2 fold). Interestingly FK506 binding protein 51 (FKBP51), structurallysimilar but functional opposite to FKBP52, did not show significant differencesin ERK1/2 phosphorylation neither c-fos endogenous protein abundance. FKBP52stimulated AP-1 transcriptional activity on a concentration dependent manner(range: 2.9 - 47 fold of increment for 0.5-1.5 µg wtFKBP52 plasmid transfected,P<0.01, n = 5). Besides, in order to analyse the effects of these regulatoryevents, we studied IL-6 secretion and MMP-2 proteolytic activity. We observedan increased on IL-6 medium concentration (2.3 ± 0.3 fold) and MMP-2 enzymaticactivity (2.5 ± 0.1 fold), abrogated by the PPIase mutants of FKBP52. Conclusions: We demonstrated that FKBP52 enhances ERK1/2 phosphorylation,increases c-fos protein abundance and AP-1 transcriptional activity as well asthe expression or activity of its target genes. We concluded that FKBP52 couldbe considering as a positive new regulator of AP-1 in trophoblast cells.  Funding: UBACyT and CONICET.