We found that PGE2 could induce expression of PTGER4, indicating a positive feedback system induced by the PTGS-PGE2 synthase-PGE2 pathway to maintain PTGER4 expression.
Indeed, LEF1 is a direct transcriptional target of the LEF1/β-catenin complex[23], indicating a positive feedback loop for Wnt signaling, and suggesting LEF1 might be useful as a prognostic biomarker of Wnt pathway activation.
In this study, we show that Atf1/Pcr1 bind at the promoter of both atf1+ and pcr1+ genes (Figure 3), indicating a positive feedback loop in transcriptional regulation of atf1+ and pcr1+ that has been hypothesized by others [14].
Increased TLR9 expression correlates with increased responsiveness to the ligand, indicating a positive feedback loop in which CpG2006 enhances its own effects [ 29].
Evidence for bidirectional causality was present as well, with changes in relaxation predicting changes in energy and vice versa, indicating a positive feedback loop.
This indicates a positive feedback for infection in these high prevalence herds and the possibility that two states may arise, herds with a stable low seroprevalence and herds with a stable high seroprevalence with different within herd dynamics.
Furthermore, our findings indicate that a positive feedback loop exists in which IL-23 can enhance its own production via the induction of IFN-γ and GM-CSF, which both prime monocytes for enhanced IL-23 production.
These data indicate that a positive feedback loop exists between COX-2 and HER2 in breast cancer cells.
The results indicate that a positive feedback mechanism regulates brain aromatase and imply that the sexual dimorphic distribution of aromatase may be highly sensitive to physiologic cues and environmental perturbations in fish.
BMPs and noggin reciprocally induce their expression in osteoblasts [23], indicating that a positive feedback is necessary for maintaining an optimal balance between BMP and noggin concentrations in the bone microenvironment.
