scholarly journals The Protein Tyrosine Phosphatase Shp2 Is Required for the Generation of Oligodendrocyte Progenitor Cells and Myelination in the Mouse Telencephalon

2014 ◽  
Vol 34 (10) ◽  
pp. 3767-3778 ◽  
Author(s):  
L. A. Ehrman ◽  
D. Nardini ◽  
S. Ehrman ◽  
T. A. Rizvi ◽  
J. Gulick ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Oligodendrocyte Progenitor Cells ◽  
Oligodendrocyte Progenitor ◽  
Protein Tyrosine

scholarly journals Loss of Protein-tyrosine Phosphatase α (PTPα) Increases Proliferation and Delays Maturation of Oligodendrocyte Progenitor Cells

2012 ◽  
Vol 287 (15) ◽  
pp. 12529-12540 ◽  
Author(s):  
Pei-Shan Wang ◽  
Jing Wang ◽  
Yi Zheng ◽  
Catherine J. Pallen
Keyword(s):  
Cell Cycle ◽  
Progenitor Cells ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Oligodendrocyte Progenitor Cells ◽  
Cell Cycle Exit ◽  
Oligodendrocyte Progenitor ◽  
Protein Tyrosine ◽  
Neural Stem Progenitor Cells

Tightly controlled termination of proliferation determines when oligodendrocyte progenitor cells (OPCs) can initiate differentiation and mature into myelin-forming cells. Protein-tyrosine phosphatase α (PTPα) promotes OPC differentiation, but its role in proliferation is unknown. Here we report that loss of PTPα enhanced in vitro proliferation and survival and decreased cell cycle exit and growth factor dependence of OPCs but not neural stem/progenitor cells. PTPα−/− mice have more oligodendrocyte lineage cells in embryonic forebrain and delayed OPC maturation. On the molecular level, PTPα-deficient mouse OPCs and rat CG4 cells have decreased Fyn and increased Ras, Cdc42, Rac1, and Rho activities, and reduced expression of the Cdk inhibitor p27Kip1. Moreover, Fyn was required to suppress Ras and Rho and for p27Kip1 accumulation, and Rho inhibition in PTPα-deficient cells restored expression of p27Kip1. We propose that PTPα-Fyn signaling negatively regulates OPC proliferation by down-regulating Ras and Rho, leading to p27Kip1 accumulation and cell cycle exit. Thus, PTPα acts in OPCs to limit self-renewal and facilitate differentiation.

scholarly journals Identification of Increased Protein Tyrosine Phosphatase Activity in Polycythemia Vera Erythroid Progenitor Cells

Blood ◽  
1997 ◽  
Vol 90 (2) ◽  
pp. 651-657 ◽  
Author(s):  
Xingwei Sui ◽  
Sanford B. Krantz ◽  
Zhizhuang Zhao
Keyword(s):  
Polycythemia Vera ◽  
Progenitor Cells ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Gel Filtration ◽  
Erythroid Progenitors ◽  
Erythroid Progenitor ◽  
Normal Cells ◽  
Protein Tyrosine ◽  
Erythroid Progenitor Cells

Abstract Polycythemia vera (PV) is a clonal hematologic disease characterized by hyperplasia of the three major bone marrow lineages. PV erythroid progenitor cells display hypersensitivity to several growth factors, which might be caused by an abnormality of tyrosine phosphorylation. In the present study, we have investigated protein tyrosine phosphatase (PTP) activity in highly purified erythroid progenitor cells and found that the total PTP activity in the PV cells was twofold to threefold higher than that in normal cells. Protein separation on anion-exchange and gel-filtration columns showed that the increased activity was due to a major PTP eluted at approximately 170 kD. This enzyme was sensitive to PTP inhibitors and it did not cross-react with antibodies to SHP-1, SHP-2, or CD45. Subcellular fractionation showed that the PTP localized with the membrane fraction, where its activity was increased by threefold in PV erythroid progenitors when compared with normal cells. As the erythroid progenitors progressively matured, activity of the PTP declined rapidly in the normal cells but at a much slower rate in the PV cells. These studies suggest that a potentially novel membrane or membrane-associated PTP, representing a major PTP activity, may have an important role in proliferation and/or survival of human erythroid progenitors and that its hyperactivation in PV erythroid progenitors might be responsible for the increased erythropoiesis in PV patients.

scholarly journals Identification of Increased Protein Tyrosine Phosphatase Activity in Polycythemia Vera Erythroid Progenitor Cells

Blood ◽  
1997 ◽  
Vol 90 (2) ◽  
pp. 651-657 ◽  
Author(s):  
Xingwei Sui ◽  
Sanford B. Krantz ◽  
Zhizhuang Zhao
Keyword(s):  
Polycythemia Vera ◽  
Progenitor Cells ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Gel Filtration ◽  
Erythroid Progenitors ◽  
Erythroid Progenitor ◽  
Normal Cells ◽  
Protein Tyrosine ◽  
Erythroid Progenitor Cells

Polycythemia vera (PV) is a clonal hematologic disease characterized by hyperplasia of the three major bone marrow lineages. PV erythroid progenitor cells display hypersensitivity to several growth factors, which might be caused by an abnormality of tyrosine phosphorylation. In the present study, we have investigated protein tyrosine phosphatase (PTP) activity in highly purified erythroid progenitor cells and found that the total PTP activity in the PV cells was twofold to threefold higher than that in normal cells. Protein separation on anion-exchange and gel-filtration columns showed that the increased activity was due to a major PTP eluted at approximately 170 kD. This enzyme was sensitive to PTP inhibitors and it did not cross-react with antibodies to SHP-1, SHP-2, or CD45. Subcellular fractionation showed that the PTP localized with the membrane fraction, where its activity was increased by threefold in PV erythroid progenitors when compared with normal cells. As the erythroid progenitors progressively matured, activity of the PTP declined rapidly in the normal cells but at a much slower rate in the PV cells. These studies suggest that a potentially novel membrane or membrane-associated PTP, representing a major PTP activity, may have an important role in proliferation and/or survival of human erythroid progenitors and that its hyperactivation in PV erythroid progenitors might be responsible for the increased erythropoiesis in PV patients.

1742-P: Targeting the Low Molecular Weight Protein Tyrosine Phosphatase for Obesity-Associated Diabetes Therapy

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 1742-P
Author(s):  
STEPHANIE M. STANFORD ◽  
MICHAEL A. DIAZ ◽  
JIWEN J. ZOU ◽  
ROBERT J. ARDECKY ◽  
ANTHONY PINKERTON ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Low Molecular Weight ◽  
Molecular Weight Protein ◽  
Diabetes Therapy ◽  
Protein Tyrosine ◽  
Weight Protein ◽  
Low Molecular Weight Protein

Inhibition of Protein Tyrosine Phosphatase 1B by Lutein Derivatives isolated from Mexican Oregano (Lippia graveolens)

2018 ◽  
Vol 17 (3) ◽  
pp. 134-139
Author(s):  
R.M. Perez-Gutierrez
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Inhibitory Activity ◽  
Spectroscopic Data ◽  
Methanol Extract ◽  
Tyrosine Phosphatase ◽  
Positive Control ◽  
Protein Tyrosine Phosphatase 1B ◽  
Protein Tyrosine ◽  
Ic50 Value ◽  
Ic50 Values

Methanol extract from Lippia graveolens (Mexican oregano) was studied in order to identify inhibitory bioactives for protein tyrosine phosphatase 1B (PTP1B). Known flavone as lutein (1), and another flavone glycoside such as lutein-7-o-glucoside (2), 6-hydroxy-lutein-7-ohexoside (3) and lutein-7-o-ramnoide (4) were isolated from methanol extract of aerial parts of the Lippia graveolens. All isolates were identified based on extensive spectroscopic data analysis, including UV, IR, NMR, MS and compared with spectroscopic data previously reported. These flavones were evaluated for PTP1B inhibitory activity. Among them, compounds 1 and 3 displayed potential inhibitory activity against PTP1B with IC50 values of 7.01 ± 1.25 μg/ml and 18.4 μg/ml, respectively. In addition, compound 2 and 4 showed moderate inhibitory activity with an IC50 value of 23.8 ± 6.21 and 67.8 ± 5.80 μg/ml respectively. Among the four compounds, luteolin was found to be the most potent PTP1B inhibitor compared to the positive control ursolic acid, with an IC50 value of 8.12 ± 1.06 μg/ml. These results indicate that flavonoids constituents contained in Lippia graveolens can be considered as a natural source for the treatment of type 2 diabetes.

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