Investigation of neutrophil signal transduction using a specific inhibitor of phosphatidylinositol 3-kinase.

Vlahos, Chris J.; Matter, William F.; Brown, Raymond F.; Traynor‐Kaplan, Alexis; Heyworth, Paul G.; Prossnitz, Eric R.; Ye, R D; Marder, Philip; Schelm, J A; Rothfuss, Kimberly J.

doi:10.4049/jimmunol.154.5.2413

Cited by 156 publications

(2 citation statements)

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“…38,44 Akt, PKC, and MAPK are also reportedly involved in signaling leading to phosphorylating p47phox. [45][46][47][48][49][50] To explore the potential roles of these molecules in regulating p47phox during platelet activation under shear, platelets were treated with inhibitors of PKC (Gö6976), PI3K (wortmannin and LY294002), Akt (SH-6 and AktX), or the MAPK pathways (p38 inhibitor SB203580, MEK inhibitor U0126), stimulated with thrombin or CRP in a platelet lumi-aggregometer and assessed for phosphorylation of p47phox by Western Blot. In both thrombin-or CRPstimulated human and mouse platelets, phosphorylation of p47phox at S 304 and S 328 was significantly inhibited by various inhibitors of PI3K and Akt (Figure VIIIA, IXA, and IXB in the Data Supplement), suggesting that a potential role for the PI3K/Akt signaling pathway in p47phox activation.…”

Section: Platelet P47phox May Be Regulated By the Pi3k/akt Pathwaymentioning

confidence: 99%

Shear and Integrin Outside-In Signaling Activate NADPH-Oxidase 2 to Promote Platelet Activation

Liang

Delaney

et al. 2021

ATVB

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Objective: Despite the importance of reactive oxygen species (ROS) and NOX (nicotinamide adenine dinucleotide phosphate [NADPH] oxidase) 2 in platelet activation and in vivo thrombosis, it is unclear how ROS and NOX2 play a role in platelet activation and why NOX2 deficiencies in humans and mice do not affect hemostasis. Outside-in signaling of integrin α IIb β 3 mediates platelet response to shear stress, secondary platelet activation, and thrombus expansion and is critical to thrombosis but dispensable for hemostasis. We studied the mechanisms of platelet ROS generation, ROS-mediated platelet response, and the role of ROS in integrin α IIb β 3 outside-in signaling. Approach and Results: ROS generation in activated platelets was low and slow without shear but was robust under shear. Shear-enhanced ROS generation and activation of p47phox, an important regulatory subunit of NOX2, were diminished by the integrin antagonist integrilin or β 3 knockout, and by Gα 13 knockout or blocking the Gα 13 -β 3 interaction. Resting platelets spreading on integrin ligand fibrinogen also Gα 13 -dependently stimulated ROS generation and p47phox activation. Hence, Gα 13 -mediated outside-in signaling induces NOX2 activation and ROS generation which is greatly enhanced by shear. Outside-in NOX2 activation requires Src, phosphoinositide 3-kinase and Akt downstream of Gα 13 . Importantly, NOX2-knockout platelets showed defective ROS generation, reduced platelet spreading without shear, and reduced platelet adhesion and thrombus volume on collagen and VWF (von Willibrand factor) under shear, whereas ROS inhibition diminished activation of tyrosine kinase Syk. Conclusions: Outside-in signaling activates the mainly NOX2-mediated ROS generation, which mediates Syk-dependent secondary platelet activation, adhesion, and thrombosis with minimal effect on hemostasis.

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Section: Platelet P47phox May Be Regulated By the Pi3k/akt Pathwaymentioning

confidence: 99%

Shear and Integrin Outside-In Signaling Activate NADPH-Oxidase 2 to Promote Platelet Activation

Liang

Delaney

et al. 2021

ATVB

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“…However, PI3K are not only crucial in mediating insulin response in adipose tissue, but are involved in recruitment of inflammatory cells as well, as PI3K are activated by cytokine and chemokine receptors in immune cells [23,86]. Early studies using pan-PI3K inhibitors reveal the role of PI3K in innate immune response by demonstrating that wortmannin or LY294002 impaired neutrophil function [87,88] and macrophage recruitment and activation [89,90]. Of note, regulation of immune cell recruitment seems to be specific to PI3Kγ, as shown in in vitro experiments using p100γ-deficient neutrophils and macrophages [91,92].…”

Section: The Role Of Pi3k/akt Signaling Pathway In Obesity and Obesit...mentioning

confidence: 99%

Targeting PI3K/AKT signaling pathway in obesity

Savova

Mihaylova

Tews

et al. 2023

Biomedicine & Pharmacotherapy

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Inhibition of MG-63 cell proliferation and PDGF-stimulated cellular processes by inhibitors of phosphatidylinositol 3-kinase

Thomas¹,

Venugopalan²,

Galvin³

et al. 1997

J. Cell. Biochem.

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Studies on a platelet-derived growth factor (PDGF) responsive osteosarcoma cell line, MG-63, were initiated to determine the effects of phosphatidylinositol (Ptdlns) 3-kinase inhibitors on serum-stimulated cell proliferation and PDGF-stimulated DNA replication, actin rearrangements, or Ptdlns 3-kinase activity. In a dose-dependent manner, the fungal metabolite wortmannin and a quercetin derivative, LY294002 (2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one), inhibited serum-stimulated MG-63 cell proliferation. The mitogenic effects of PDGF on MG-63 cells, as determined by incorporation of [3H]-thymidine, were also substantially inhibited in the presence of 0.10 microM wortmannin or 10 microM Ly294002. Furthermore, MG-63 cells stimulated by PDGF form distinct actin-rich, finger-like membrane projections which are completely inhibited by either 0.10 microM wortmannin or 10 microM LY294002. At these same concentrations, wortmannin and LY294002 were also effective at reducing levels of phosphatidylinositol 3-phosphate in PDGF-stimulated MG-63 cells. Treatment of these cells with increasing concentrations of wortmannin reduced the level of PDGF stimulated tyrosine phosphorylation of the PDGF receptor but did not significantly affect the amount of the Ptdlns 3-kinase regulatory subunit, p85, associated with the receptor. Additionally, pretreatment of cells with 0.250 microM wortmannin followed by stimulation with PDGF resulted in a slightly reduced level of receptor autokinase activity; however, similar treatment with 50 microM LY294002 did not affect the level of autokinase activity. These results demonstrate the effects of two different Ptdlns 3-kinase inhibitors on serum- and PDGF-stimulated MG-63 cell proliferation and PDGF-stimulated morphological changes and suggest a greater role for Ptdlns 3-kinase in these processes.

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Investigation of neutrophil signal transduction using a specific inhibitor of phosphatidylinositol 3-kinase.

Cited by 156 publications

References 0 publications

Shear and Integrin Outside-In Signaling Activate NADPH-Oxidase 2 to Promote Platelet Activation

Shear and Integrin Outside-In Signaling Activate NADPH-Oxidase 2 to Promote Platelet Activation

Targeting PI3K/AKT signaling pathway in obesity

Inhibition of MG-63 cell proliferation and PDGF-stimulated cellular processes by inhibitors of phosphatidylinositol 3-kinase

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