scholarly journals Peroxynitrite modulates tyrosine phosphorylation and phosphoinositide signalling in human neuroblastoma SH-SY5Y cells: attenuated effects in human 1321N1 astrocytoma cells

1998 ◽  
Vol 331 (2) ◽  
pp. 599-606 ◽  
Author(s):  
Xiaohua LI ◽  
Patrizia De SARNO ◽  
Ling SONG ◽  
Joseph S. BECKMAN ◽  
Richard S. JOPE

Peroxynitrite may contribute to oxidative stress involving neurodegeneration in several disorders, including Alzheimer's disease. As with other reactive oxygen species, peroxynitrite might affect neuronal signalling systems, actions that could contribute to adaptive or deleterious cellular outcomes, but such effects have not previously been studied. To address this issue directly, peroxynitrite (50–500 µM) was administered to human neuroblastoma SH-SY5Y cells to assess its effects on protein tyrosine nitration, phosphoinositide signalling and protein tyrosine phosphorylation. Peroxynitrite rapidly increased the nitrotyrosine immunoreactivity of numerous proteins, primarily in the cytosol. Peroxynitrite inhibited, in a concentration-dependent manner, phosphoinositide hydrolysis stimulated by activation of muscarinic receptors with carbachol and the inhibition was greater after the depletion of cellular glutathione. In comparison, muscarinic receptor-stimulated phosphoinositide hydrolysis in human astrocytoma 1321N1 cells was less vulnerable to inhibition by peroxynitrite either without or with prior depletion of glutathione. There was a large, rapid and reversible increase in the tyrosine phosphorylation of the p120 Src substrate in peroxynitrite-treated SH-SY5Y cells, a response that was potentiated by glutathione depletion; in contrast, peroxynitrite decreased the tyrosine phosphorylation of focal adhesion kinase and paxillin. Tyrosine phosphorylation of p120 in 1321N1 astrocytoma cells was less sensitive to modulation by peroxynitrite. Thus alterations in phosphoinositide signalling and protein tyrosine phosphorylation were greater in neuroblastoma than astrocytoma cells, and modulation of these signalling processes probably contributes to neuronal mechanisms of the response to peroxynitrite.

1996 ◽  
Vol 75 (04) ◽  
pp. 648-654 ◽  
Author(s):  
Naoki Asazuma ◽  
Yutaka Yatomi ◽  
Yukio Ozaki ◽  
Ruomei Qi ◽  
Kenji Kuroda ◽  
...  

SummaryIn human platelets treated with acetylsalicylic acid, collagen induced protein-tyrosine-phosphorylation of several proteins. The major 75 kDa band included cortactin and autophosphorylated p72 syk . p72 syk activity rapidly increased upon collagen stimulation, whereas p60c-src activation was below detectable levels. A combination of inhibitors to remove the effects of extracellular and intracellular Ca2+, released ADP, and fibrinogen binding to GPIIb/IIIa delayed and attenuated the major 75 kDa band. By contrast, p72 syk activation was not inhibited by these treatments. Cytochalasin D completely inhibited protein tyrosine phosphorylation and p72 syk activation. It also potently inhibited aggregation and [Ca2+]i elevation. Anti-GPMIa/IIa MoAb in a concentration-dependent manner partially attenuated protein tyrosine phosphorylation and p72 syk activation. Its inhibitory effects on intracellular Ca2+ mobilization, release of intracellular granule contents, and aggregation also were partial. No tyrosine kinase activity was coprecipitated with GPIa/IIa. These results suggest that p72 syk activation lies upstream of protein tyrosine phosphorylation, Ca2+ mobilization, ADP release, thromboxane A2 production and aggregation. GPIa/IIa plays a key role in p72 syk activation induced by collagen, but other collagen receptors may work in synergy to fully activate p72 syk . Actin polymerization is a prerequisite for both p72 syk activation and other intracellular signal transduction pathways.


Development ◽  
1995 ◽  
Vol 121 (4) ◽  
pp. 1139-1150 ◽  
Author(s):  
P.E. Visconti ◽  
G.D. Moore ◽  
J.L. Bailey ◽  
P. Leclerc ◽  
S.A. Connors ◽  
...  

In the accompanying report (Visconti, P.E., Bailey, J.L., Moore, G.D., Pan, D., Olds-Clarke, P. and Kopf, G.S. (1995) Development, 121, 1129–1137) we demonstrated that the tyrosine phosphorylation of a subset of mouse sperm proteins of M(r) 40,000-120,000 was correlated with the capacitation state of the sperm. The mechanism by which protein tyrosine phosphorylation is regulated in sperm during this process is the subject of this report. Cauda epididymal sperm, when incubated in media devoid of NaHCO3, CaCl2 or bovine serum albumin do not display the capacitation-associated increases in protein tyrosine phosphorylation of this subset of proteins. This NaHCO3, CaCl2 or bovine serum albumin requirement for protein tyrosine phosphorylation can be completely overcome by the addition of biologically active, but not inactive, cAMP analogues. Addition of the active cAMP analogues to sperm incubated in media devoid of NaHCO3, CaCl2 or bovine serum albumin overcomes the inability of these media to support capacitation, as assessed by the ability of the cells to acquire the pattern B chlortetracycline fluorescence, to undergo the zona pellucida-induced acrosome reaction and, in some cases, to fertilize metaphase II-arrested eggs in vitro. The effects of the cAMP analogues to enhance protein tyrosine phosphorylation and to promote capacitation appears to be at the level of the cAMP-dependent protein kinase (PKA), since two specific inhibitors of this enzyme (H-89 and Rp-cAMPS) block the capacitation-dependent increases in protein tyrosine phosphorylation in sperm incubated in media supporting capacitation. Capacitation, as assessed by the aforementioned endpoints, also appears to be inhibited by H-89 in a concentration-dependent manner. These results provide further evidence for the interrelationship between protein tyrosine phosphorylation and the appearance of the capacitated state in mouse sperm. They also demonstrate that both protein tyrosine phosphorylation and capacitation appear to be regulated by cAMP/PKA. Up-regulation of protein tyrosine phosphorylation by cAMP/PKA in sperm is, to our knowledge, the first demonstration of such an interrelationship between tyrosine kinase/phosphatase and PKA signaling pathways.


Development ◽  
1995 ◽  
Vol 121 (4) ◽  
pp. 1129-1137 ◽  
Author(s):  
P.E. Visconti ◽  
J.L. Bailey ◽  
G.D. Moore ◽  
D. Pan ◽  
P. Olds-Clarke ◽  
...  

The molecular basis of mammalian sperm capacitation, defined functionally as those processes that confer on the sperm the acquisition of fertilization-competence either in vivo in the female reproductive tract or in vitro, is poorly understood. We demonstrate here that capacitation of caudal epididymal mouse sperm in vitro is accompanied by a time-dependent increase in the protein tyrosine phosphorylation of a subset of proteins of M(r) 40,000-120,000. Incubation of sperm in media devoid of bovine serum albumin, CaCl2 or NaHCO3, components which individually are required for capacitation, prevent the sperm from undergoing capacitation as assessed by the ability of the cells to acquire the pattern B chlortetracycline fluorescence, to undergo the zona pellucida-induced acrosome reaction and, in some cases, to fertilize metaphase II-arrested eggs in vitro. In each of these cases the protein tyrosine phosphorylation of the subset of capacitation-associated proteins does not occur. Protein tyrosine phosphorylation of these particular proteins, as well as sperm capacitation, can be recovered in media devoid of each of these three constituents (bovine serum albumin, CaCl2 or NaHCO3) by adding back the appropriate component in a concentration-dependent manner. The requirement of NaHCO3 for these phosphorylations is not due to an alkalinization of intracellular sperm pH or to an increase in media pH. Caput epididymal sperm, which lack the ability to undergo capacitation in vitro, do not display this capacitation-dependent subset of tyrosine phosphorylated proteins in complete media even after extended incubation periods, and do not fertilize metaphase II-arrested eggs in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)


1996 ◽  
Vol 271 (3) ◽  
pp. L400-L408 ◽  
Author(s):  
V. Natarajan ◽  
S. Vepa ◽  
R. S. Verma ◽  
W. M. Scribner

Oxidant-induced activation of phospholipase D (PLD) in bovine pulmonary artery endothelial cells (BPAEC) is independent of protein kinase C and calcium. In the present study, the effects of tyrosine kinase and protein tyrosine phosphatase (PTPase) inhibitors on hydrogen peroxide (H2O2)-induced PLD activation and protein tyrosine phosphorylation were examined in BPAEC. Pretreatment of BPAEC with putative tyrosine kinase inhibitors genistein, tyrphostin, and herbimycin attenuated H2O2 (1 mM)-induced PLD activation. The inhibitory effect of the tyrosine kinase inhibitors was highly specific for H2O2-induced modulation and showed no effect on PLD activation mediated by 12-O-tetradecanoylphorbol 13-acetate or bradykinin. Furthermore, addition of H2O2 increased in a time-dependent manner tyrosine phosphorylation of several proteins (17-200 kDa), as determined by immunoblot analysis with antiphosphotyrosine antibodies. H2O2-mediated protein tyrosine phosphorylation preceded PLD activation, and a good correlation was observed on the effect of genistein in H2O2-induced PLD activation and protein tyrosine phosphorylation. Addition of vanadate, a phosphotyrosine phosphatase inhibitor, synergistically increased both PLD activation and protein tyrosine phosphorylation mediated by H2O2. Moreover, vanadate by itself had minimal effect on basal PLD activity in BPAEC; however, at 10 microM vanadate, an increase in protein tyrosine phosphorylation was observed. In addition to vanadate, phenylarsine oxide and diamide potentiated H2O2-induced PLD activation. These results suggest that tyrosine kinase activation may be involved in H2O2-induced PLD activation in vascular endothelial cells.


1990 ◽  
Vol 10 (12) ◽  
pp. 6290-6298
Author(s):  
W R Huckle ◽  
C A Prokop ◽  
R C Dy ◽  
B Herman ◽  
S Earp

Cellular responses to epidermal growth factor (EGF) are dependent on the tyrosine-specific protein kinase activity of the cell-surface EGF receptor. Previous studies using WB rat liver epithelial cells have detected at least 10 proteins whose phosphotyrosine (P-Tyr) content is increased by EGF. In this study, we have examined alternate modes of activating tyrosine phosphorylation. Treatment of WB cells with hormones linked to Ca2+ mobilization and protein kinase C (PKC) activation, including angiotensin II, [Arg8]vasopressin, or epinephrine, stimulated rapid (less than or equal to 15-s) and transient increases in the P-Tyr content of several proteins (p120/125, p75/78, and p66). These proteins, detected by anti-P-Tyr immunoblotting, were similar in molecular weight to a subset of EGF-sensitive P-Tyr-containing proteins (P-Tyr-proteins). The increased P-Tyr content was confirmed by [32P]phosphoamino acid analysis of proteins recovered by anti-P-Tyr immunoprecipitation. Elevating intracellular [Ca2+] with the ionophore A23187 or ionomycin or with the tumor promoter thapsigargin mimicked the effects of hormones on tyrosine phosphorylation, whereas treatment with a PKC-activating phorbol ester did not. In addition, responses to angiotensin II were not diminished in PKC-depleted cells. Ca2+ mobilization, measured by fura-2 fluorescence, was coincident with the increase in tyrosine phosphorylation in response to angiotensin II or thapsigargin. Loading cells with the intracellular Ca2+ chelator bis-(o-aminophenoxy)ethane-N ,N ,N' , N'-tetraacetic acid (BAPTA) inhibited the appearance of all P-Tyr-proteins in response to angiotensin II, thapsigargin, or ionophores, as well as two EGF-stimulated P-Tyr-proteins. The majority of EGF-stimulated P-Tyr-proteins were not affected by BAPTA. These studies indicate that angiotensin II can alter protein-tyrosine phosphorylation in a manner that is secondary to, and apparently dependent on, Ca2+ mobilization. Thus, ligands such as EGF and angiotensin II, which act through distinct types of receptors, may activate secondary pathways involving tyrosine phosphorylation. These results also raise the possibility that certain growth-promoting effects of Ca2+ -mobilizing agents such as angiotensin II may be mediated via tyrosine phosphorylation.


1990 ◽  
Vol 10 (12) ◽  
pp. 6290-6298 ◽  
Author(s):  
W R Huckle ◽  
C A Prokop ◽  
R C Dy ◽  
B Herman ◽  
S Earp

Cellular responses to epidermal growth factor (EGF) are dependent on the tyrosine-specific protein kinase activity of the cell-surface EGF receptor. Previous studies using WB rat liver epithelial cells have detected at least 10 proteins whose phosphotyrosine (P-Tyr) content is increased by EGF. In this study, we have examined alternate modes of activating tyrosine phosphorylation. Treatment of WB cells with hormones linked to Ca2+ mobilization and protein kinase C (PKC) activation, including angiotensin II, [Arg8]vasopressin, or epinephrine, stimulated rapid (less than or equal to 15-s) and transient increases in the P-Tyr content of several proteins (p120/125, p75/78, and p66). These proteins, detected by anti-P-Tyr immunoblotting, were similar in molecular weight to a subset of EGF-sensitive P-Tyr-containing proteins (P-Tyr-proteins). The increased P-Tyr content was confirmed by [32P]phosphoamino acid analysis of proteins recovered by anti-P-Tyr immunoprecipitation. Elevating intracellular [Ca2+] with the ionophore A23187 or ionomycin or with the tumor promoter thapsigargin mimicked the effects of hormones on tyrosine phosphorylation, whereas treatment with a PKC-activating phorbol ester did not. In addition, responses to angiotensin II were not diminished in PKC-depleted cells. Ca2+ mobilization, measured by fura-2 fluorescence, was coincident with the increase in tyrosine phosphorylation in response to angiotensin II or thapsigargin. Loading cells with the intracellular Ca2+ chelator bis-(o-aminophenoxy)ethane-N ,N ,N' , N'-tetraacetic acid (BAPTA) inhibited the appearance of all P-Tyr-proteins in response to angiotensin II, thapsigargin, or ionophores, as well as two EGF-stimulated P-Tyr-proteins. The majority of EGF-stimulated P-Tyr-proteins were not affected by BAPTA. These studies indicate that angiotensin II can alter protein-tyrosine phosphorylation in a manner that is secondary to, and apparently dependent on, Ca2+ mobilization. Thus, ligands such as EGF and angiotensin II, which act through distinct types of receptors, may activate secondary pathways involving tyrosine phosphorylation. These results also raise the possibility that certain growth-promoting effects of Ca2+ -mobilizing agents such as angiotensin II may be mediated via tyrosine phosphorylation.


1994 ◽  
Vol 72 (06) ◽  
pp. 973-978 ◽  
Author(s):  
Hiromasa Shimizu ◽  
Hiroshi Takayama ◽  
Jong-Dae Lee ◽  
Kazuo Satake ◽  
Takanobu Taniguchi ◽  
...  

SummaryThe ability of vanadate, an inhibitor of protein-tyrosine phosphatases, to affect the production of prostacyclin (PGI2) and endothelin-1 (ET-1) and protein-tyrosine phosphorylation in human umbilical vein endothelial cells (HUVEC) was studied. The addition of vanadate to monolayers of cultured HUVEC caused a sustained release of PGI2 from HUVEC in a time- and dose-dependent manner. When aspirin-treated HUVEC, which have lost the ability to increase PGI2 production in response to arachidonate, were incubated with vanadate, the cells recovered their ability to increase PGI2 production in response to arachidonate. This recovery of inducible PGI2 production in aspirin-treated HUVEC was completely inhibited either by cycloheximide, a protein synthesis inhibitor, or by actinomycin D, an RNA synthesis inhibitor. In contrast, the same concentration of vanadate suppressed the basal release of ET-1 from HUVEC. Vanadate also caused an increase in protein-tyrosine phosphorylation in HUVEC. These data indicate that vanadate induces opposite effects on PGI2 and ET-1 production with a concomitant increase in protein-tyrosine phosphorylation in HUVEC.


2004 ◽  
Vol 101 (6) ◽  
pp. 1325-1331 ◽  
Author(s):  
Jingui Yu ◽  
Koji Ogawa ◽  
Yasuyuki Tokinaga ◽  
Kazuhiro Mizumoto ◽  
Tetsuya Kakutani ◽  
...  

Background Tyrosine kinase-catalyzed protein tyrosine phosphorylation plays an important role in initiating and modulating vascular smooth muscle contraction. The aim of the current study was to examine the effects of isoflurane on sodium orthovanadate (Na3VO4), a potent protein tyrosine phosphatase inhibitor-induced, tyrosine phosphorylation-mediated contraction of rat aortic smooth muscle. Methods The Na3VO4-induced contraction of rat aortic smooth muscle and tyrosine phosphorylation of proteins including phospholipase Cgamma-1 (PLCgamma-1) and p44/p42 mitogen-activated protein kinase (MAPK) were assessed in the presence of different concentrations of isoflurane, using isometric force measurement and Western blotting methods, respectively. Results Na3VO4 (10(-4) m) induced a gradually sustained contraction and significant increase in protein tyrosine phosphorylation of a set of substrates including PLCgamma-1 and p42MAPK, all of which were markedly inhibited by genistein (5 x 10(-5) m), a tyrosine kinase inhibitor. Isoflurane (1.2-3.5%) dose-dependently depressed the Na3VO4-induced contraction (P < 0.05-0.005; n = 8). Isoflurane also attenuated the total density of the Na3VO4-induced, tyrosine-phosphorylated substrate bands and the density of tyrosine-phosphorylated PLCgamma-1 band and p42MAPK band (P < 0.05-0.005; n = 4) in a concentration-dependent manner. Conclusion The findings of the current study, that isoflurane dose-dependently inhibits both the Na3VO4-stimulated contraction and tyrosine phosphorylation of a set of proteins including PLCgamma-1 and p42MAPK in rat aortic smooth muscle, suggest that isoflurane depresses protein tyrosine phosphorylation-modulated contraction of vascular smooth muscle, especially that mediated by the tyrosine-phosphorylated PLCgamma-1 and MAPK signaling pathways.


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