Tyrosine kinase regulates epithelial sodium transport in A6 cells

1993 ◽  
Vol 264 (1) ◽  
pp. C246-C250 ◽  
Author(s):  
P. S. Matsumoto ◽  
A. Ohara ◽  
P. Duchatelle ◽  
D. C. Eaton
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitors ◽  
Kinase Activity ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Na Transport ◽  
Tyrosine Kinase Activity ◽  
Open Probability ◽  
Cyclic Monophosphate ◽  
Tyrphostin 23

Insulin increases epithelial Na+ reabsorption, and many of its actions involve tyrosine kinase. We used tyrosine kinase inhibitors to examine the role of tyrosine kinase in the action of insulin. Pretreatment of Na+ transporting cells with tyrosine kinase inhibitors attenuates the subsequent action of insulin, suggesting that the action of insulin on epithelial Na+ transport involves tyrosine kinase activity. In addition to their effect on insulin-induced Na+ transport, the tyrosine kinase inhibitors also significantly reduce Na+ transport in Na(+)-transporting epithelial cells, suggesting that there is a significant tonic tyrosine kinase activity that modulates epithelial Na+ transport. Using patch-clamp methods, we found that one inhibitor, genistein, reduces the number of active Na+ channels in cell-attached patches without significantly affecting the open probability of any remaining channels. The effects of the tyrosine kinase inhibitors are not due to inhibition of protein kinase A (PKA), since H89, a PKA inhibitor, does not affect Na+ transport of control cells (as the tyrosine kinase inhibitors do), and the tyrosine kinase inhibitor, genistein or tyrphostin 23, does not alter the stimulation of ion transport by 8-(4-chlorophenylthio)adenosine 3',5'-cyclic monophosphate, a membrane-permeable adenosine 3',5'-cyclic monophosphate analogue (as H89 does).

Identification of surrogate markers for determining drug activity using proteomics

2003 ◽  
Vol 31 (6) ◽  
pp. 1488-1490 ◽  
Author(s):  
C.M. McClelland ◽  
W.J. Gullick
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitors ◽  
Kinase Activity ◽  
Kinase Inhibitors ◽  
Drug Evaluation ◽  
New Drugs ◽  
Hydroxyl Groups ◽  
Surrogate Markers ◽  
Tyrosine Kinase Activity ◽  
Drug Activity

In a high proportion of human carcinomas overexpression of the EGFR (epidermal growth factor receptor), a receptor tyrosine kinase, represents a potential target for cancer treatment. EGFR is induced to dimerize through ligand binding which activates the tyrosine kinase activity of the receptor. This catalyses the transfer of ATP's γ-phosphate to hydroxyl groups of tyrosine residues on the receptor, creating binding sites that recruit downstream signalling proteins. New drugs, SMTKIs (small-molecule tyrosine kinase inhibitors), have been designed to inhibit the tyrosine kinase activity of the receptor, producing an anti-tumour effect. The development of surrogate markers to determine the drug activity of these new inhibitors would be of great benefit in drug evaluation and in the subsequent management of patient disease. This review describes current treatments of cancer using tyrosine kinase inhibitors and the use of proteomic analysis to identify possible markers of activity of these new drugs.

Modulation of Excitability in Aplysia Tail Sensory Neurons by Tyrosine Kinases

2001 ◽  
Vol 85 (6) ◽  
pp. 2398-2411 ◽  
Author(s):  
Angela L. Purcell ◽  
Thomas J. Carew
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitors ◽  
Sensory Neurons ◽  
Tyrosine Kinases ◽  
Kinase Activity ◽  
Kinase Inhibitors ◽  
Direct Injection ◽  
Tyrosine Phosphatase ◽  
Tyrosine Kinase Activity ◽  
Activity Dependent

Tyrosine kinases have recently been shown to modulate synaptic plasticity and ion channel function. We show here that tyrosine kinases can also modulate both the baseline excitability state of Aplysia tail sensory neurons (SNs) as well as the excitability induced by the neuromodulator serotonin (5HT). First, we examined the effects of increasing and decreasing tyrosine kinase activity in the SNs. We found that tyrosine kinase inhibitors decrease baseline SN excitability in addition to attenuating the increase in excitability induced by 5HT. Conversely, functionally increasing cellular tyrosine kinase activity in the SNs by either inhibiting opposing tyrosine phosphatase activity or by direct injection of an active tyrosine kinase (Src) induces increases in SN excitability in the absence of 5HT. Second, we examined the interaction between protein kinase A (PKA), which is known to mediate 5HT-induced excitability changes in the SNs, and tyrosine kinases, in the enhancement of SN excitability. We found that the tyrosine kinases function downstream of PKA activation since tyrosine kinase inhibitors reduce excitability induced by activators of PKA. Finally, we examined the role of tyrosine kinases in other forms of 5HT-induced plasticity in the SNs. We found that while tyrosine kinase inhibitors attenuate excitability produced by 5HT, they have no effect on short-term facilitation (STF) of the SN-motor neuron (MN) synapse induced by 5HT. Thus tyrosine kinases modulate different forms of SN plasticity independently. Such differential modulation would have important consequences for activity-dependent plasticity in a variety of neural circuits.

scholarly journals Thrombotic microangiopathy in dasatinib-treated patients with chronic myeloid leukemia

2019 ◽  
Vol 4 (1-2) ◽  
pp. 41-45 ◽  
Author(s):  
Takeo Koshida ◽  
Sylvia Wu ◽  
Hitoshi Suzuki ◽  
Rimda Wanchoo ◽  
Vanesa Bijol ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitor ◽  
Tyrosine Kinase Inhibitors ◽  
Thrombotic Microangiopathy ◽  
Myeloid Leukemia ◽  
Kinase Inhibitors ◽  
Kidney Biopsy ◽  
Kinase Inhibitor ◽  
Target Effect

Dasatinib is the second-generation tyrosine kinase inhibitor used in the treatment of chronic myeloid leukemia. Proteinuria has been reported with this agent. We describe two kidney biopsy–proven cases of dasatinib-induced thrombotic microangiopathy that responded to stoppage of dasatinib and using an alternate tyrosine kinase inhibitor. Certain specific tyrosine kinase inhibitors lead to endothelial injury and renal-limited thrombotic microangiopathy. Hematologists and nephrologists need to be familiar with this off-target effect of dasatinib.

scholarly journals Transmission of growth cone traction force through apCAM–cytoskeletal linkages is regulated by Src family tyrosine kinase activity

2001 ◽  
Vol 155 (3) ◽  
pp. 427-438 ◽  
Author(s):  
Daniel M. Suter ◽  
Paul Forscher
Keyword(s):  
Tyrosine Kinase ◽  
Growth Cone ◽  
Kinase Activity ◽  
Kinase Inhibitors ◽  
Traction Force ◽  
Tyrosine Kinase Activity ◽  
Cellular Mechanisms ◽  
Traction Forces ◽  
Kinase Activation ◽  
Neuronal Growth Cone

Tyrosine kinase activity is known to be important in neuronal growth cone guidance. However, underlying cellular mechanisms are largely unclear. Here, we report how Src family tyrosine kinase activity controls apCAM-mediated growth cone steering by regulating the transmission of traction forces through receptor–cytoskeletal linkages. Increased levels of tyrosine phosphorylation were detected at sites where beads coated with apCAM ligands were physically restrained to induce growth cone steering, but not at unrestrained bead binding sites. Interestingly, the rate and level of phosphotyrosine buildup near restrained beads were decreased by the myosin inhibitor 2,3-butanedione-2-monoxime, suggesting that tension promotes tyrosine kinase activation. While not affecting retrograde F-actin flow rates, genistein and the Src family selective tyrosine kinase inhibitors PP1 and PP2 strongly reduced the growth cone's ability to apply traction forces through apCAM–cytoskeletal linkages, assessed using the restrained bead interaction assay. Furthermore, increased levels of an activated Src family kinase were detected at restrained bead sites during growth cone steering events. Our results suggest a mechanism by which growth cones select pathways by sampling both the molecular nature of the substrate and its ability to withstand the application of traction forces.

The patient with renal cell cancer

2015 ◽  
Author(s):  
Tim Eisen
Keyword(s):  
Tyrosine Kinase ◽  
Cell Carcinoma ◽  
Tyrosine Kinase Inhibitors ◽  
Renal Cancer ◽  
Renal Cell Cancer ◽  
Renal Cell ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Cell Cancer

Renal cancer is the commonest malignancy of the kidney and worldwide, accounts for between 2% and 3% of the total cancer burden. The mainstay of curative treatment remains surgery. There have been significant advances in surgical technique, the most important ones being nephron-sparing surgery and laparoscopic nephrectomy. The medical treatment of advanced renal cell cancer has only improved markedly in the last decade with the development of antiangiogenic tyrosine-kinase inhibitors, inhibitors of mammalian target of rapamycin, and a diminished role for immunotherapy.Tyrosine-kinase inhibitor therapy results in reduction of tumour volume in around three-quarters of patients and doubles progression-free survival, but treatment is not curative. The management of side effects in patients on maintenance tyrosine-kinase inhibitors has improved in the last 3 years, although still presents difficulties which have to be actively considered.The molecular biology of renal cell carcinoma is better understood than for the majority of solid tumours. The commonest form of renal cancer, clear-cell carcinoma of the kidney, is strongly associated with mutations in the von Hippel–Lindau gene and more recently with chromatin-remodelling genes such as PBRM1. These genetic abnormalities lead to a loss of control of angiogenesis and uncontrolled proliferation of tumour cells. There is a very wide spectrum of tumour behaviour from the extremely indolent to the terribly aggressive. It is not currently known what accounts for this disparity in tumour behaviour.A number of outstanding questions are being addressed in scientific and clinical studies such as a clearer understanding of prognostic and predictive molecular biomarkers, the role of adjuvant therapy, the role of surgery in the presence of metastatic disease, how best to use our existing agents, and investigation of novel targets and therapeutic agents, especially novel immunotherapies.

Platelet/Polymorphonuclear Leukocyte Interaction: P-Selectin Triggers Protein-Tyrosine Phosphorylation–Dependent CD11b/CD18 Adhesion: Role of PSGL-1 as a Signaling Molecule

Blood ◽  
1999 ◽  
Vol 93 (3) ◽  
pp. 876-885 ◽  
Author(s):  
Virgilio Evangelista ◽  
Stefano Manarini ◽  
Rita Sideri ◽  
Serenella Rotondo ◽  
Nicola Martelli ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Tyrosine Kinase Inhibitors ◽  
Polymorphonuclear Leukocyte ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Chinese Hamster ◽  
Mixed Cell ◽  
Β2 Integrin ◽  
Activated Platelets

Abstract Polymorphonuclear leukocyte (PMN) adhesion to activated platelets is important for the recruitment of PMN at sites of vascular damage and thrombus formation. We have recently shown that binding of activated platelets to PMN in mixed cell suspensions under shear involves P-selectin and the activated β2-integrin CD11b/CD18. Integrin activation required signaling mechanisms that were sensitive to tyrosine kinase inhibitors.1 Here we show that mixing activated, paraformaldehyde (PFA)-fixed platelets with PMNs under shear conditions leads to rapid and fully reversible tyrosine phosphorylation of a prominent protein of 110 kD (P∼110). Phosphorylation was both Ca2+ and Mg2+ dependent and was blocked by antibodies against P-selectin or CD11b/CD18, suggesting that both adhesion molecules need to engage with their respective ligands to trigger phosphorylation of P∼110. The inhibition of P∼110 phosphorylation by tyrosine kinase inhibitors correlates with the inhibition of platelet/PMN aggregation. Similar effects were observed when platelets were substituted by P-selectin–transfected Chinese hamster ovary (CHO-P) cells or when PMN were stimulated with P-selectin–IgG fusion protein. CHO-P/PMN mixed-cell aggregation and P-selectin–IgG–triggered PMN/PMN aggregation as well as P∼110 phosphorylation were all blocked by antibodies against P-selectin or CD18. In each case PMN adhesion was sensitive to the tyrosine kinase inhibitor genistein. The antibody PL-1 against P-selectin glycoprotein ligand-1 (PSGL-1) blocked platelet/PMN aggregation, indicating that PSGL-1 was the major tethering ligand for P-selectin in this experimental system. Moreover, engagement of PSGL-1 with a nonadhesion blocking antibody triggered β2-integrin–dependent genistein-sensitive aggregation as well as tyrosine phosphorylation in PMN. This study shows that binding of P-selectin to PSGL-1 triggers tyrosine kinase–dependent mechanisms that lead to CD11b/CD18 activation in PMN. The availability of the β2-integrin to engage with its ligands on the neighboring cells is necessary for the tyrosine phosphorylation of P∼110.

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