scholarly journals Inhibition of Phosphatidylinositol 3-Kinase by Pictilisib Blocks Influenza Virus Propagation in Cells and in Lungs of Infected Mice

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 808
Author(s):  
Stefanie Deinhardt-Emmer ◽  
Laura Jäckel ◽  
Clio Häring ◽  
Sarah Böttcher ◽  
Janine J. Wilden ◽  
...  

Influenza virus (IV) infections are considered to cause severe diseases of the respiratory tract. Beyond mild symptoms, the infection can lead to respiratory distress syndrome and multiple organ failure. Occurrence of resistant seasonal and pandemic strains against the currently licensed antiviral medications points to the urgent need for new and amply available anti-influenza drugs. Interestingly, the virus-supportive function of the cellular phosphatidylinositol 3-kinase (PI3K) suggests that this signaling module may be a potential target for antiviral intervention. In the sense of repurposing existing drugs for new indications, we used Pictilisib, a known PI3K inhibitor to investigate its effect on IV infection, in mono-cell-culture studies as well as in a human chip model. Our results indicate that Pictilisib is a potent inhibitor of IV propagation already at early stages of infection. In a murine model of IV pneumonia, the in vitro key findings were verified, showing reduced viral titers as well as inflammatory response in the lung after delivery of Pictilisib. Our data identified Pictilisib as a promising drug candidate for anti-IV therapies that warrant further studying. These results further led to the conclusion that the repurposing of previously approved substances represents a cost-effective and efficient way for development of novel antiviral strategies.

2007 ◽  
Vol 88 (3) ◽  
pp. 942-950 ◽  
Author(s):  
Yeun-Kyung Shin ◽  
Qiang Liu ◽  
Suresh K. Tikoo ◽  
Lorne A. Babiuk ◽  
Yan Zhou

The phosphatidylinositol 3-kinase (PI3K)/Akt signalling pathway has attracted much recent interest due to its central role in modulating diverse downstream signalling pathways associated with cell survival, proliferation, differentiation, morphology and apoptosis. An increasing amount of information has demonstrated that many viruses activate the PI3K/Akt pathway to augment their efficient replication. In this study, the effect of the PI3K/Akt signalling pathway on influenza virus propagation was investigated. It was found that Akt phosphorylation was elevated in the late phase of influenza A/PR/8/34 infection in human lung carcinoma cells (A549). The PI3K-specific inhibitor LY294002 could suppress Akt phosphorylation, suggesting that influenza A virus-induced Akt phosphorylation is PI3K-dependent. UV-irradiated influenza virus failed to induce Akt phosphorylation, indicating that viral attachment and entry were not sufficient to trigger PI3K/Akt pathway activation. Blockage of PI3K/Akt activation by LY294002 and overexpression of the general receptor for phosphoinositides-1 PH domain (Grp1-PH) led to a reduction in virus yield. Moreover, in the presence of LY294002, viral RNA synthesis and viral protein expression were suppressed and, possibly as a consequence of low NP and M1 protein level, viral RNP nuclear export was also suppressed. These data suggest that the PI3K/Akt signalling pathway plays a role in influenza virus propagation.


2021 ◽  
pp. 106767
Author(s):  
Gizele A.L. Silva ◽  
Luana B. Araújo ◽  
Larissa C.R. Silva ◽  
Bruna B. Gouveia ◽  
Ricássio S. Barberino ◽  
...  

2013 ◽  
Vol 14 (7) ◽  
pp. 13577-13591 ◽  
Author(s):  
Wennan Zhao ◽  
Wenzhi Guo ◽  
Qianxiang Zhou ◽  
Sheng-Nan Ma ◽  
Ran Wang ◽  
...  

1998 ◽  
Vol 18 (7) ◽  
pp. 4131-4140 ◽  
Author(s):  
Christopher D. Kontos ◽  
Thomas P. Stauffer ◽  
Wen-Pin Yang ◽  
John D. York ◽  
Liwen Huang ◽  
...  

ABSTRACT Tie2 is an endothelium-specific receptor tyrosine kinase that is required for both normal embryonic vascular development and tumor angiogenesis and is thought to play a role in vascular maintenance. However, the signaling pathways responsible for the function of Tie2 remain unknown. In this report, we demonstrate that the p85 subunit of phosphatidylinositol 3-kinase (PI3-kinase) associates with Tie2 and that this association confers functional lipid kinase activity. Mutation of tyrosine 1101 of Tie2 abrogated p85 association both in vitro and in vivo in yeast. Tie2 was found to activate PI3-kinase in vivo as demonstrated by direct measurement of increases in cellular phosphatidylinositol 3-phosphate and phosphatidylinositol 3,4-bisphosphate, by plasma membrane translocation of a green fluorescent protein-Akt pleckstrin homology domain fusion protein, and by downstream activation of the Akt kinase. Activation of PI3-kinase was abrogated in these assays by mutation of Y1101 to phenylalanine, consistent with a requirement for this residue for p85 association with Tie2. These results suggest that activation of PI3-kinase and Akt may in part account for Tie2’s role in both embryonic vascular development and pathologic angiogenesis, and they are consistent with a role for Tie2 in endothelial cell survival.


2019 ◽  
Vol 116 (17) ◽  
pp. 8269-8274 ◽  
Author(s):  
Yasuko Araki ◽  
Takayoshi Awakawa ◽  
Motomichi Matsuzaki ◽  
Rihe Cho ◽  
Yudai Matsuda ◽  
...  

Ascofuranone (AF) and ascochlorin (AC) are meroterpenoids produced by various filamentous fungi, includingAcremonium egyptiacum(synonym:Acremonium sclerotigenum), and exhibit diverse physiological activities. In particular, AF is a promising drug candidate against African trypanosomiasis and a potential anticancer lead compound. These compounds are supposedly biosynthesized through farnesylation of orsellinic acid, but the details have not been established. In this study, we present all of the reactions and responsible genes for AF and AC biosyntheses inA. egyptiacum, identified by heterologous expression, in vitro reconstruction, and gene deletion experiments with the aid of a genome-wide differential expression analysis. Both pathways share the common precursor, ilicicolin A epoxide, which is processed by the membrane-bound terpene cyclase (TPC) AscF in AC biosynthesis. AF biosynthesis branches from the precursor by hydroxylation at C-16 by the P450 monooxygenase AscH, followed by cyclization by a membrane-bound TPC AscI. All genes required for AC biosynthesis (ascABCDEFG) and a transcriptional factor (ascR) form a functional gene cluster, whereas those involved in the late steps of AF biosynthesis (ascHIJ) are present in another distantly located cluster. AF is therefore a rare example of fungal secondary metabolites requiring multilocus biosynthetic clusters, which are likely to be controlled by the single regulator, AscR. Finally, we achieved the selective production of AF inA. egyptiacumby genetically blocking the AC biosynthetic pathway; further manipulation of the strain will lead to the cost-effective mass production required for the clinical use of AF.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Na Han ◽  
Yaqun Jiang ◽  
Yongkang Gai ◽  
Qingyao Liu ◽  
Lujie Yuan ◽  
...  

Pictilisib (GDC-0941) is an inhibitor of phosphatidylinositol 3-kinase (PI3K), part of a signaling cascade involved in breast cancer development. The purpose of this study was to evaluate the pharmacokinetics of pictilisib noninvasively by radiolabeling it with 11C and to assess the usability of the resulting [11C]-pictilisib as a positron-emission tomography (PET) tracer to screen for pictilisib-sensitive tumors. In this study, pictilisib was radiolabeled with [11C]-methyl iodide to obtain 11C-methylated pictilisib ([11C]-pictilisib) using an automated synthesis module with a high radiolabeling yield. Considerably higher uptake ratios were observed in MCF-7 (PIK3CA mutation, pictilisib-sensitive) cells than those in MDA-MB-231 (PIK3CA wild-type, pictilisib-insensitive) cells at all evaluated time points, indicating good in vitro binding of [11C]-pictilisib. Dynamic micro-PET scans in mice and biodistribution results showed that [11C]-pictilisib was mainly excreted via the hepatobiliary tract into the intestines. MCF-7 xenografts could be clearly visualized on the static micro-PET scans, while MDA-MB-231 tumors could not. Biodistribution results of two xenograft models showed significantly higher uptake and tumor-to-muscle ratios in the MCF-7 xenografts than those in MDA-MB-231 xenografts, exhibiting high in vivo targeting specificity. In conclusion, [11C]-pictilisib was first successfully prepared, and it exhibited good potential to identify pictilisib-sensitive tumors noninvasively, which may have a great impact in the treatment of cancers with an overactive PI3K/Akt/mTOR signal pathway. However, the high activity in hepatobiliary system and intestines needs to be addressed.


2002 ◽  
Vol 13 (4) ◽  
pp. 1252-1262 ◽  
Author(s):  
Dale J. Powner ◽  
Matthew N. Hodgkin ◽  
Michael J.O. Wakelam

Phospholipase D (PLD) activity can be detected in response to many agonists in most cell types; however, the pathway from receptor occupation to enzyme activation remains unclear. In vitro PLD1b activity is phosphatidylinositol 4,5-bisphosphate dependent via an N-terminal PH domain and is stimulated by Rho, ARF, and PKC family proteins, combinations of which cooperatively increase this activity. Here we provide the first evidence for the in vivo regulation of PLD1b at the molecular level. Antigen stimulation of RBL-2H3 cells induces the colocalization of PLD1b with Rac1, ARF6, and PKCα at the plasma membrane in actin-rich structures, simultaneously with cooperatively increasing PLD activity. Activation is both specific and direct because dominant negative mutants of Rac1 and ARF6 inhibit stimulated PLD activity, and surface plasmon resonance reveals that the regulatory proteins bind directly and independently to PLD1b. This also indicates that PLD1b can concurrently interact with a member from each regulator family. Our results show that in contrast to PLD1b's translocation to the plasma membrane, PLD activation is phosphatidylinositol 3-kinase dependent. Therefore, because inactive, dominant negative GTPases do not activate PLD1b, we propose that activation results from phosphatidylinositol 3-kinase–dependent stimulation of Rac1, ARF6, and PKCα.


1993 ◽  
Vol 13 (12) ◽  
pp. 7677-7688 ◽  
Author(s):  
P Hu ◽  
A Mondino ◽  
E Y Skolnik ◽  
J Schlessinger

Phosphatidylinositol 3-kinase (PI 3-kinase) has been implicated as a participant in signaling pathways regulating cell growth by virtue of its activation in response to various mitogenic stimuli. Here we describe the cloning of a novel and ubiquitously expressed human PI 3-kinase. The 4.8-kb cDNA encodes a putative translation product of 1,070 amino acids which is 42% identical to bovine PI 3-kinase and 28% identical to Vps34, a Saccharomyces cerevisiae PI 3-kinase involved in vacuolar protein sorting. Human PI 3-kinase is also similar to Tor2, a yeast protein required for cell cycle progression. Northern (RNA) analysis demonstrated expression of human PI 3-kinase in all tissues and cell lines tested. Protein synthesized from an epitope-tagged cDNA had intrinsic PI 3-kinase activity and associated with the adaptor 85-kDa subunit of PI 3-kinase (p85) in intact cells, as did endogenous human PI 3-kinase. Coprecipitation assays showed that a 187-amino-acid domain between the two src homology 2 domains of p85 mediates interaction with PI 3-kinase in vitro and in intact cells. These results demonstrate the existence of different PI 3-kinase isoforms and define a family of genes encoding distinct PI 3-kinase catalytic subunits that can associate with p85.


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