PP2 regulates human trophoblast cells differentiation by activating p38 and ERK1/2 and inhibiting FAK activation.
ABSTRACT Throughout gestation, fetal growth and development depend, in part, on placental transfer of nutrients from the maternal circulation. This latter function depends on multinucleated, terminally differentiated syncytiotrophoblasts. In vitro, freshly isolated cytotrophoblast cells differentiate spontaneously into syncytiotrophoblast in the presence of fetal bovine serum (FBS). We have previously showed that trophoblast differentiation is regulated by ERK1/2 and p38. Moreover, we showed that PP2 [4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3, 4-d]pyrimidine], a Src family kinase (SFK) specific inhibitor, stimulates biochemical trophoblast cells differentiation while it inhibits cell adhesion and spreading without affecting cell fusion. Therefore, we examined the mechanisms by which PP2 modulates trophoblast cells differentiation. This study shows that PP2 stimulates ERK1/2 and p38 activation after 24h of treatments and up to 3 days while it inhibits focal adhesion kinase (FAK) phosphorylation at many sites including Tyr-397, 407, 576 and 577. Furthermore, we showed that transient activation of ERK1/2 by FBS is independent of SFK and that PP2 induces rapid activation of p38. Moreover, the kinase activity of SFK is negatively regulated by the phosphorylation of their carboxy (C)-terminal regulatory tyrosines by specific proteins called carboxyl-terminal Src kinase (Csk) and Csk homologous kinase (CHK). We showed the expression of Csk and CHK in human trophoblast cells. In summary, this study showed that PP2 stimulates the biochemical differentiation of trophoblast cells by stimulating p38 and ERK1/2 while it inhibits the morphological differentiation by inhibiting FAK activation.
- SourceAvailable from: Amel Guezguez[Show abstract] [Hide abstract]
ABSTRACT: The proto-oncogene Src is an important protein tyrosine kinase involved in signaling pathways that control cell adhesion, growth, migration and survival. Here, we investigated the involvement of Src family kinases (SFKs) in human intestinal cell differentiation. We first observed that Src activity peaked in early stages of Caco-2/15 cell differentiation. Inhibition of SFKs with PP2, a selective SFK inhibitor, accelerated the overall differentiation program. Interestingly, all polarization and terminal differentiation markers tested, including sucrase-isomaltase, lactase-phlorizin hydrolase and E and LI-cadherins were found to be significantly up-regulated after only 3 days of treatment in the newly differentiating cells. Further investigation of the effects of PP2 revealed a significant up-regulation of the two main intestinal epithelial cell-specific transcription factors Cdx2 and HNF1α and a reduction of polycomb PRC2-related epigenetic repressing activity as measured by a decrease in H3K27me3, two events closely related to the control of cell terminal differentiation in the intestine. Taken together, these data suggest that SFKs play a key role in the control of intestinal epithelial cell terminal differentiation.Biochemical and Biophysical Research Communications 12/2012; · 2.28 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: BACKGROUND: It has been reported recently that PP2, a Src family kinase inhibitor, promotes selective cardiogenesis in embryonic stem cells. However, there is no other research proved pro-cardiogenic characteristic of PP2 so far. In this study, we explored the potential cardiogenic effect of PP2 on P19 cells differentiation. METHODS: P19-αMHC-EGFP cell line was established by transfecting P19 cells with αMHC-EGFP vector in order to evaluate cardiogenesis with EGFP. P19-αMHC-EGFP cells and P19 cells were induced to differentiate into cardiomyocytes with 1%DMSO, 5μmol/L PP2, or both 1%DMSO and 5μmol/L PP2. Differentiated cells from P19-αMHC-EGFP cells were then assessed under confocal microscope. Western-blot and RT-PCR were also performed to detect expression of cardiac troponin I and cardiac transcription factors respectively. In addition, the effects of PP2 on proliferation of P19 cells were further examined using Cell Counting Kit-8. RESULTS: EGFP positive cells were firstly detected on day 7 and PP2 alone cannot induce efficient cardiac differentiation of P19-αMHC-EGFP cells. However PP2 supplementation dramatically increases DMSO induced cardiac differentiation than DMSO alone. It was also found that PP2 inhibit proliferation of P19 cells in both a dose-dependent manner and a time-dependent manner. CONCLUSION: PP2 alone cannot substitute DMSO to induce cardiac differentiation, however, PP2 supplementation drastically promotes DMSO-induced cardiac differentiation of P19 cells. The increased percentages of differentiated cardiac myocytes is partly resulting from cell proliferative inhibit effect of PP2 in undifferentiated P19 cells. P19-αMHC-EGFP cell line has the potential to be used for regenerative therapies in experimental models of heart repair.International journal of cardiology 05/2012; · 6.18 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Gynecologic cancer is a major health burden in women across the world. Almost a half million mortalities from gynecologic cancer were reported every year. Knowledge in molecular biology research on cancer could lead to develope novel therapeutic options in gynecologic cancer. Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase which plays an essential role in cancer cells survival, migration, invasion, metastasis and also tumor angiogenesis. Various human cancerous tissues were demonstrated over expression of FAK which were correlated to the survival. There were evidences showed that FAK involved in molecular pathways of ovarian cancer, endometrial cancer and cervical cancer. In the light of this review, FAK has been a promising mediator that regulates cancer growth and metastasis. Therefore, molecular therapies targeted FAK may be beneficial for patients with gynecologic cancer in the near future.