/LEF inhibitor iCRT14, which inhibits Wnt signalling downstream of Frizzled. Treatment with Wnt-Conditioned Media increased 2883-98-9 reporter activity to a similar level as Fz-MNP after 6h, with maximum activity observed after 24h. This effect was blocked using Dkk1 or iCRT14 with reporter activity being reduced to basal levels. Control particles coated with either Rabbit-IgG or RGD peptide caused no 
increase in reporter activity at 6h or 24h with or without magnetic field. Values represent mean fold change in luciferase activity relative to cells only with luciferase activity normalised to total protein. Error bars represent SEM, n = 4, denotes p<0.05, # denotes p 0.05 doi:10.1371/journal.pone.0121761.g005 Fz-MNP activate a TCF/LEF reporter A Gaussia luciferase reporter under control of a TCF/LEF promoter was used to directly asses the transcriptional activity of Wnt target genes in response to Fz-MNP, Wnt conditioned media and magnetic field stimulation over 24h. Transfected hMSC showed an increase in luciferase reporter activity at 6h after treatment with Fz-MNP or Wnt-CM. An added significant increase in reporter activity was observed when cells were treated with Fz-MNP 10 / 18 Remote Activation of Wnt Signalling with magnetic field. The increase in reporter activity PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19763407 by Wnt-CM was successfully blocked using the Wnt LRP5/6 co-receptor blocker Dkk1 and iCRT14, a downstream Wnt signalling blocker that disrupts -catenin association and interaction with TCF transcription factors which are required for expression of Wnt target genes. In contrast Dkk1 had no effect on reporter activity when cells were treated with Fz-MNP but these effects were blocked using iCRT14. At 24h Fz-MNP treated groups showed a moderate increase in reporter activity with an added significant effect when magnetic field stimulation was applied. Treatment with Wnt-CM also significantly activated reporter activity at 24h which was again blocked with Dkk1 or iCRT14. Treatment with Dkk1 again had no effect on reporter activity at 24h when used in conjunction with Fz-MNP whereas iCRT 14 also blocked reporter activation at 24h. Magnetic field treatment alone again increased reporter activity.. Control particles IgG-MNP and RGDMNP were both found to have a negligible effect on reporter activation after 6h and 24h. Fz-MNP alter stress response gene expression Gene expression analysis for stress response genes c-Myc, Cox2 and NF-B was also performed at early time-points to investigate the levels of mechano-stimulation on cells. As predicted, treatment with the control particles caused a significant up-regulation in NF-B expression after 1h followed by a down-regulation in expression after 3h when compared to cells + magnet control groups. All other groups showed small but not significant levels of elevation at 1 and 3 hours compared to the TREK labelled response to magnetic field. Investigations of responses in two other early response genes c-Myc and Cox2 showed low level variations in expression but none to the same extent as the NF-B response observed to TREK coated particles with oscillating magnetic field. Small elevations in c-Myc expression were observed in all groups at 1 hour which PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19763758 fell by 3 hours with the most significant again observed in the TREK activated magnetic particle group. Similar levels of elevation were observed in Wnt3A activation as with particles alone, particles with magnetic field and magnetic field alone. A similar low level pattern of response was observed