Protein tyrosine phosphatase-1B and T-cell protein tyrosine phosphatase regulate IGF-2-induced MCF-7 cell migration

2010 ◽  
Vol 392 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Christophe Blanquart ◽  
Salah-Eddine Karouri ◽  
Tarik Issad
2006 ◽  
Vol 281 (12) ◽  
pp. 8010-8015 ◽  
Author(s):  
Ernest Asante-Appiah ◽  
Sangita Patel ◽  
Caroline Desponts ◽  
Jillian M. Taylor ◽  
Cheuk Lau ◽  
...  

2020 ◽  
Vol 401 (10) ◽  
pp. 1167-1180
Author(s):  
María Eugenia Chamorro ◽  
Romina Maltaneri ◽  
Agustina Schiappacasse ◽  
Alcira Nesse ◽  
Daniela Vittori

AbstractThe proliferation and migration of endothelial cells are vascular events of inflammation, a process which can also potentiate the effects of promigratory factors. With the aim of investigating possible modifications in the activity of erythropoietin (Epo) in an inflammatory environment, we found that Epo at a non-promigratory concentration was capable of stimulating EA.hy926 endothelial cell migration when TNF-α was present. VCAM-1 and ICAM-1 expression, as well as adhesion of monocytic THP-1 cells to endothelial layers were also increased. Structurally modified Epo (carbamylation or N-homocysteinylation) did not exhibit these effects. The sensitizing effect of TNF-α on Epo activity was mediated by the Epo receptor. Inhibition assays targeting the PI3K/mTOR/NF-κB pathway, shared by Epo and TNF-α, show a cross-talk between both cytokines. As observed in assays using antioxidants, cell migration elicited by TNF-α + Epo depended on TNF-α-generated reactive oxygen species (ROS). ROS-mediated inactivation of protein tyrosine phosphatase 1B (PTP1B), involved in Epo signaling termination, could explain the synergistic effect of these cytokines. Our results suggest that ROS generated by inflammation inactivate PTP1B, causing the Epo signal to last longer. This mechanism, along with the cross-talk between both cytokines, could explain the sensitizing action of TNF-α on the migratory effect of Epo.


2006 ◽  
Vol 17 (11) ◽  
pp. 4846-4855 ◽  
Author(s):  
Susann Karlsson ◽  
Katarzyna Kowanetz ◽  
Åsa Sandin ◽  
Camilla Persson ◽  
Arne Östman ◽  
...  

We have previously shown that the T-cell protein tyrosine phosphatase (TC-PTP) dephosphorylates the platelet-derived growth factor (PDGF) β-receptor. Here, we show that the increased PDGF β-receptor phosphorylation in TC-PTP knockout (ko) mouse embryonic fibroblasts (MEFs) occurs primarily on the cell surface. The increased phosphorylation is accompanied by a TC-PTP–dependent, monensin-sensitive delay in clearance of cell surface PDGF β-receptors and delayed receptor degradation, suggesting PDGF β-receptor recycling. Recycled receptors could also be directly detected on the cell surface of TC-PTP ko MEFs. The effect of TC-PTP depletion was specific for the PDGF β-receptor, because PDGF α-receptor homodimers were cleared from the cell surface at the same rate in TC-PTP ko MEFs as in wild-type MEFs. Interestingly, PDGF αβ-receptor heterodimers were recycling. Analysis by confocal microscopy revealed that, in TC-PTP ko MEFs, activated PDGF β-receptors colocalized with Rab4a, a marker for rapid recycling. In accordance with this, transient expression of a dominant-negative Rab4a construct increased the rate of clearance of cell surface receptors on TC-PTP ko MEFs. Thus, loss of TC-PTP specifically redirects the PDGF β-receptor toward rapid recycling, which is the first evidence of differential trafficking of PDGF receptor family members.


2001 ◽  
Vol 276 (28) ◽  
pp. 26036-26043 ◽  
Author(s):  
Ernest Asante-Appiah ◽  
Kristen Ball ◽  
Kevin Bateman ◽  
Kathryn Skorey ◽  
Rick Friesen ◽  
...  

Author(s):  
Chang-An Geng ◽  
Zhen-Tao Deng ◽  
Qian Huang ◽  
Chun-Lei Xiang ◽  
Ji-Jun Chen

AbstractTen 3,5-dimethylcoumarins (1–6 and 8‒11) involving six new ones (1–6), together with a known 3-methylcoumarin (7), were isolated from the aerial parts of three Chelonopsis plants, C. praecox, C. odontochila, and C. pseudobracteata. The structures of the new compounds were determined by extensive HRESIMS, 1D and 2D NMR spectroscopic analyses. According to the substitution at C-5, these coumarins were classified into 5-methyl, 5-hydroxymethyl, 5-formyl, and 5-nor types. All the isolates were assayed for their inhibition on α-glucosidase, protein tyrosine phosphatase 1B, and T-cell protein tyrosine phosphatase in vitro. Graphic Abstract


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