Role of Slit2/Robo1 in trophoblast invasion and vascular remodeling during ectopic tubal pregnancy.

INTRODUCTION: For ectopic tubal pregnancy to be viable, it requires a supporting vascular network and functioning trophoblast. Slit2/Robo1 signaling plays an important role in placental angiogenesis during normal pregnancy. Hence, we here investigated whether or not Slit2/Robo1 signaling also had an impact in ectopic tubal pregnancy. METHODS: The Slit2 and Robo1 expression pattern relevant to trophoblast invasive behavior and vascular remodeling was studied in human tubal placenta obtained from patients with ectopic pregnancy (5-8weeks gestation), The trophoblast development, vascular architecture and Robo1 expression pattern were observed in Slit2 overexpression (Slit2-Tg) and C57BL mice placenta (E13.5 and E15.5). RESULTS: Marked with CK-7 and Vimentin, the vessel profiles of fallopian tube were classified into four stages. In the presence of extravillous trophoblast (EVT), stellate-shaped and polygonal-shaped EVTs were observed, and the stellate-shaped EVT showed the higher Slit2 expression (P < 0.01) but lower Robo1 expression (P < 0.05) than polygonal-shaped cells. By contrast, a temporary Slit2 up-regulation in remodeling vessel and Slit2 down-regulation in remodeled vessel of polygonal-shape extravillous trophoblast cells occurred in tubal pregnancies. In Slit2-Tg mice E13.5 and E15.5 placenta, Slit2 overexpression promoted vascular remodeling by increasing in the diameter of the maternal blood sinusoids and fetal capillaries, but enhanced the thickness of trophoblast and vasculature at E15.5 Slit2-Tg mice. CONCLUSIONS: The varying Slit2 and Robo1 expression in EVTs was associated with trophoblast invasion and probably plays an important role in the events of blood vessel remodeling of the fallopian tube tissues.

The second-generation mTOR kinase inhibitor INK128 exhibits anti-inflammatory activity in lipopolysaccharide-activated RAW 264.7 cells.

Cross-talk between the mTOR (mechanistic target of rapamycin) and NF-κB (nuclear factor kappa-B) pathways has been reported to regulate macrophage responses to lipopolysaccharide (LPS). In this study, we aimed to explore the effect of INK128, a second-generation inhibitor of mTOR, on the inflammatory cytokine production in LPS-stimulated RAW 264.7 cells. Our data showed that INK128 strikingly inhibited the phosphorylation of p70S6K, 4E-BP1 and AKTSer473 in both unstimulated and LPS-stimulated cells. Although it increased the phosphorylation levels of inhibitor kappa-B (IκB) in LPS-stimulated cells, INK128 did not significantly change the levels of NF-κB phosphorylation. In addition, LPS-induced expression of IL-1ß and IL-6 was markedly suppressed by INK128 at both mRNA and protein levels. However, the expression of Tumor necrosis factor-alpha (TNF-α protein), but not its mRNA level, was suppressed by this reagent. Our results suggest that the mTOR inhibitor INK128 not only regulates the NF-κB signaling but also influences the inflammatory cytokine expression at both transcriptional and translational levels.