PMA inhibits endothelial cell migration through activating the PKC-δ/Syk/NF-κB-mediated up-regulation of Thy-1

Abstract

We previously showed that overexpression of Thy-1 inhibited and knock-down of Thy-1 enhanced endothelial cell migration. Here, we used phorbol-12-myristate-13-acetate (PMA) as an inducer for Thy-1 expression to investigate molecular mechanisms underlying Thy-1 up-regulation. Our data showed that increased levels of Thy-1 mRNA and protein in endothelial cells were observed at 14–18 hours and 20–28 hours after PMA treatment, respectively. Treatment with PMA for 32 hours induced Thy-1 up-regulation and inhibited capillary-like tube formation and endothelial cell migration. These effects were abolished by Röttlerin (a PKC-δ inhibitor), but not Gö6976 (a PKC-α/β inhibitor). Moreover, pre-treatment with Bay 61–3606 (a Syk inhibitor) or Bay 11-7082 (a NF-κB inhibitor) abolished the PMA-induced Thy-1 up-regulation and migration inhibition in endothelial cells. Using the zebrafish model, we showed that PMA up-regulated Thy-1 and inhibited angiogenesis through the PKC-δ-mediated pathway. Surprisingly, we found that short-term (8–10 hours) PMA treatment enhanced endothelial cell migration. However, this effect was not observed in PMA-treated Thy-1-overexpressed endothelial cells. Taken together, our results suggest that PMA initially enhanced endothelial cell migration, subsequently activating the PKC-δ/Syk/NF-κB-mediated pathway to up-regulate Thy-1, which in turn inhibited endothelial cell migration. Our results also suggest that Thy-1 might play a role in termination of angiogenesis.

Acute Kidney Injury Induced Lupus Exacerbation Through the Enhanced Neutrophil Extracellular Traps (and Apoptosis) in Fcgr2b Deficient Lupus Mice With Renal Ischemia Reperfusion Injury

“…However, PMA similarly induced NETs in neutrophils of both mouse strains at 4 h post-stimulation, while LPS inducing higher NETs (Figures 6G, H, 7) with the prominent pro-inflammatory cytokine production (TNF-a and IL-6) (Figures 8A-C) in Fcgr2b-/-than WT cells. Because spleen tyrosine kinase (Syk) and nuclear factor kappa B (NFkB), a downstream signaling of Syk (68), are the possible shared downstream signaling of PMA and LPS (20,21,69,70), these molecules are explored. At 4 h post-stimulation, PMA upregulated Syk only in Fcgr2b-/-neutrophils, while LPS upregulated Syk in neutrophils of both mouse strains (Figures 8D, E).…”

Multiple mechanisms of Rottlerin toxicity in A375 melanoma cells

“…As Figure demonstrates, the rottlerin exposure led to a drop in cyclin D1 as early as after 2 hr. This rottlerin effect can be ascribed to the inhibition of the transcription factor Nuclear Factor Kappa B (NFκB), whose nuclear migration is prevented by rottlerin in a number of cells …”

“…This rottlerin effect can be ascribed to the inhibition of the transcription factor Nuclear Factor Kappa B (NFκB), whose nuclear migration is prevented by rottlerin in a number of cells. 13,[24][25][26] Since another known NFκB gene target is the antiapoptotic Bcl-2 protein, we also measured its expression levels by Western blotting. As shown in Figure 2, the levels of Bcl-2 decrease progressively after 6-24 hr of rottlerin exposure.…”

Separate administration of ammonium pyrrolidinedithiocarbamate and phorbol myristate acetate at early and late stages decreases secondary brain injury following intracerebral haemorrhage in rats via the NF-κB pathway

“…Therefore, we concluded that both p65 inhibition at the early stage and c-Rel promotion at the late stage might reduce apoptosis more effectively. Phorbol myristate acetate (PMA) is an activator of NF-κB [10,24,25]. In this study, we administered PDTC at the early stage and PMA at the late stage after ICH, and then detected changes in NF-κB activation, subunit expression, apoptosis, and apoptotic factors.…”