Inhibition of ICE-Related Proteases (Caspases) and Nuclear Apoptosis by Phenylarsine Oxide

Tight junction permeability control is important in a variety of physiological and pathological processes. We have investigated the role of tyrosine phosphorylation in the regulation of tight junction permeability. MDCK epithelial cells and brain endothelial cells were grown on filters and tight junction permeability was determined by transcellular electrical resistance (TER). The tyrosine phosphatase inhibitor pervanadate caused a concentration- and time-dependent decrease in TER in both MDCK and brain endothelial cells. However, as expected, pervanadate resulted in the tyrosine phosphorylation of many proteins; hence interpretation of its effects are extremely difficult. Phenylarsine oxide, a more selective tyrosine phosphatase inhibitor, caused the tyrosine phosphorylation of relatively few proteins as analyzed by immunoblotting of whole cell lysates. This inhibitor, like pervanadate, also elicited a decrease in TER in the two cell types. In the MDCK cells, the action of phenylarsine oxide could be reversed by the subsequent addition of the reducing agent 2,3-dimercaptopropanol. Immunocytochemistry revealed that phenylarsine oxide rapidly stimulated the tyrosine phosphorylation of proteins associated with intercellular junctions. Because of the known influence of the adherens junction on tight junctions, we analyzed immunoprecipitates of the E-cadherin/catenin complex from MDCK cells treated with phenylarsine oxide. This revealed an increase in the tyrosine phosphorylation of beta-catenin, but not of alpha-catenin. However, the tight junction associated protein ZO-1 was also tyrosine phosphorylated after PAO treatment. These data indicate that tight junction permeability may be regulated via mechanisms involving tyrosine phosphorylation of adherens junction and tight junction proteins.

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Activation of potassium-dependent H+ efflux from mitochondria by cadmium and phenylarsine oxide

Journal of Bioenergetics and Biomembranes ◽

10.1007/bf00743214 ◽

1981 ◽

Vol 13 (5-6) ◽

pp. 425-431 ◽

Cited By ~ 21

Author(s):

D. Rao Sanadi ◽

James B. Hughes ◽

Saroj Joshi

Keyword(s):

Phenylarsine Oxide

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Phenylarsine oxide inhibited β-adrenergic receptor-mediated IL-6 secretion: Inhibition of cAMP accumulation and CREB activation in cardiac fibroblasts

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2006.11.082 ◽

2007 ◽

Vol 352 (3) ◽

pp. 744-749 ◽

Cited By ~ 6

Author(s):

Jian-Hai Du ◽

Tong-Ju Guan ◽

Hui Zhang ◽

Han Xiao ◽

Qi-De Han ◽

...

Keyword(s):

Adrenergic Receptor ◽

Cardiac Fibroblasts ◽

Camp Accumulation ◽

Phenylarsine Oxide ◽

Creb Activation ◽

Secretion Inhibition

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Regulation of the thyroid NADPH-dependent H2O2 generator by Ca2+: studies with phenylarsine oxide in thyroid plasma membrane

Biochemical Journal ◽

10.1042/bj3210383 ◽

1997 ◽

Vol 321 (2) ◽

pp. 383-388 ◽

Cited By ~ 17

Author(s):

Yves GORIN ◽

Anne Marie LESENEY ◽

Renée OHAYON ◽

Corinne DUPUY ◽

Jacques POMMIER ◽

...

Keyword(s):

Nadph Oxidase ◽

Plasma Membranes ◽

Direct Action ◽

Native Enzyme ◽

Thiol Groups ◽

Phenylarsine Oxide ◽

Oxidoreductase Activity ◽

H2o2 Formation ◽

Partial Inactivation ◽

Dose Dependent

Pig thyroid plasma membranes contain a Ca2+-dependent NADPH:O2 oxidoreductase, the thyroid NADPH-dependent H2O2 generator. This provided the H2O2 for the peroxidase-catalysed synthesis of thyroid hormones. The effect of the tervalent arsenical, phenylarsine oxide (PAO), on the NADPH oxidase was studied. PAO caused two directly related dose-dependent effects with similar half-effect concentrations of PAO (3 nmol of PAO/mg of protein): (i) partial inactivation of H2O2 formation by the Ca2+-stimulated enzyme, and (ii) desensitization of the enzyme activity to Ca2+. PAO had no effect on membranes that had been Ca2+-desensitized by α-chymotrypsin treatment. The NADPH oxidase in membranes treated with excess PAO had the same Vmax with and without Ca2+. This value was half the Vmax of the native enzyme. However, the Km for NADPH determined with Ca2+ (18 ƁM, identical with that of the native enzyme) was approx. one-third of the Km measured without Ca2+, showing the direct action of Ca2+ on the PAOŐenzyme complex. PAO had the same effects, partial inactivation and Ca2+ desensitization, on the NADPH:ferricyanide oxidoreductase activity of the NADPH oxidase, suggesting that PAO acts on the flavodehydrogenase entity of the enzyme. Both partial inactivation and Ca2+ desensitization were completely and specifically reversed by 2,3-dimercaptopropanol, partly reversed by dithiothreitol and not reversed by 2-mercaptoethanol, indicating that PAO binds to vicinal thiol groups. These results suggest that thiol groups are involved in the control of thyroid NADPH oxidase by Ca2+; PAO bound to vicinal thiols might alter the structure of the enzyme so that electron transfer occurs without Ca2+ but more slowly.

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A Nanotheranostic System Combining Lysosomal Cell Death and Nuclear Apoptosis Functions for Synergistic Cancer Therapy and Addressing Drug Resistance

Advanced Functional Materials ◽

10.1002/adfm.202106091 ◽

2021 ◽

pp. 2106091

Author(s):

Youmei Li ◽

Qian Wu ◽

Dan Li ◽

Jiachang Huang ◽

Haifei Wen ◽

...

Keyword(s):

Drug Resistance ◽

Cell Death ◽

Cancer Therapy ◽

Nuclear Apoptosis

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Sequential degradation of proteins from the nuclear envelope during apoptosis

Journal of Cell Science ◽

10.1242/jcs.114.20.3643 ◽

2001 ◽

Vol 114 (20) ◽

pp. 3643-3653 ◽

Cited By ~ 2

Author(s):

Madeleine Kihlmark ◽

Gabriela Imreh ◽

Einar Hallberg

Keyword(s):

Nuclear Envelope ◽

Apoptotic Cell ◽

Nuclear Periphery ◽

Condensed Chromatin ◽

Nuclear Pore ◽

Dependent Manner ◽

Nuclear Pores ◽

Double Labeling ◽

Lamin B ◽

Nuclear Apoptosis

We have produced new antibodies specific for the integral pore membrane protein POM121. Using these antibodies we show that during apoptosis POM121 becomes proteolytically degraded in a caspase-dependent manner. The POM121 antibodies and antibodies specific for other proteins of the nuclear envelope were used in a comparative study of nuclear apoptosis in staurosporine-treated buffalo rat liver cells. Nuclei from these cells were classified in three different stages of apoptotic progression: stage I, moderately condensed chromatin surrounded by a smooth nuclear periphery; stage II, compact patches of condensed chromatin collapsing against a smooth nuclear periphery; stage III, round compact chromatin bodies surrounded by grape-shaped nuclear periphery. We have performed double labeling immunofluorescence microscopy of individual apoptotic cells and quantitative immunoblotting analysis of total proteins from apoptotic cell cultures. The results showed that degradation of nuclear envelope marker proteins occurred in a specific order. POM121 degradation occurred surprisingly early and was initiated before nucleosomal DNA degradation could be detected using TUNEL assay and completed before clustering of the nuclear pores. POM121 was eliminated significantly more rapid compared with NUP153 (a peripheral protein located in the nucleoplasmic basket of the nuclear pore complex) and lamin B (a component of the nuclear lamina). Disappearance of NUP153 and lamin B was coincident with onset of DNA fragmentation and clustering of nuclear pores. By contrast, the peripheral NPC protein p62 was degraded much later. The results suggest that degradation of POM121 may be an important early step in propagation of nuclear apoptosis.

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