Calpain activation in plasma membrane bleb formation during tert-butyl hydroperoxide-induced rat hepatocyte injury

Miyoshi, Hideyuki; Umeshita, Koji; Sakon, Masato; Imajoh‐Ohmi, Shinobu; Fujitani, Kazumasa; Gotoh, Mitsukazu; Oiki, Eiji; Kambayashi, Jun-ichi; Monden, Morito

doi:10.1053/gast.1996.v110.pm8964416

Cited by 131 publications

(110 citation statements)

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“…Since cell membrane bleb formation is an irreversible phenomenon leading to cell necrosis, the role of calpain activation in cell membrane blebbing through the proteolysis of cytoskeletal proteins [15] is considered to be particularly important. Furthermore, we have previously reported that talin and α-actinin were degraded simultaneously with calpain μ activation in oxidative stress-induced hepatocyte injur y, and that all these events were suppressed by a specific calpain inhibitor, calpeptin [10][11][12][13][14] . Thus, the beneficial effects of prednisolone on hepatic ischemia-reperfusion injury may be at least due to inhibition of calpain μ activation.…”

Section: Discussionmentioning

confidence: 97%

“…Although the molecular mechanisms of bleb formation are unknown at present, Ca 2+ -dependent disruption of the cytoskeleton is considered to play an important role in the blebbing of plasma membrane [8,9] . Calpain μ, a Ca 2+ -sensitive for m of Ca 2+ -activated neutral protease (EC 3,4,22,17), has been shown to degrade various cytoskeletal proteins such as talin, α-actinin and filamin [10][11][12][13][14] .…”

Section: Introductionmentioning

confidence: 99%

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Protective effect of prednisolone on ischemia-induced liver injury in rats

Wang¹,

Shen²,

Shi³

et al. 2008

WJG

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AIM:To investigate the effects of prednisolone on cell membrane bleb formation, calpain μ activation and talin degradation during hepatic ischemia-reperfusion injury in rats. METHODS:The hilar area of the left lateral and median lobes of rat liver (68%) was clamped for 60 min and followed by 120 min reperfusion. Prednisolone was administered at 1.0, 3.0, or 10 mg/kg at 30 min before ischemia. In addition to biochemical and microscopic analyses, activation of calpain μ was determined using specific antibodies against the intermediate (activated) form of calpain μ. Degradation of talin was also studied by Western blotting. RESULTS: In the control and prednisolone (1.0 mg/kg) groups, serum aspartate transaminase (AST) and alanine transaminase (ALT) level were elevated, and cell membrane bleb formation was observed after 120 min of reperfusion. Moreover, calpain μ activation and talin degradation were detected. Infusion of prednisolone at 3.0 or 10 mg/kg significantly suppressed serum AST and ALT, and prevented cell membrane bleb formation. At 10 mg/kg, prednisolone markedly suppressed calpain μ activation and talin degradation. CONCLUSION: Prednisolone can suppress ischemiareperfusion injury of the rat liver. Its cytoprotective effect is closely associated with the suppression of calpain μ activation and talin degradation.

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Section: Discussionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Protective effect of prednisolone on ischemia-induced liver injury in rats

Wang¹,

Shen²,

Shi³

et al. 2008

WJG

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“…Exposure to agents that produce hydroperoxides or the addition of exogenous hydroperoxides also causes elevation of intracellular Ca 2ϩ in some cells (60). Because Ca 2ϩ release after exposure to H 2 O 2 is well documented together with calpain activation under oxidative stress conditions (62,63), it is clear why I B␣ phosphorylation in the PEST sequence becomes a substrate for degradation by calpains.…”

Section: Discussionmentioning

confidence: 99%

Crucial Role of the Amino-Terminal Tyrosine Residue 42 and the Carboxyl-Terminal PEST Domain of IκBα in NF-κB Activation by an Oxidative Stress

Schoonbroodt

Ferreira²,

Best‐Belpomme

et al. 2000

The Journal of Immunology

230

172

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Activation of transcription factor NF-κB involves the signal-dependent degradation of basally phosphorylated inhibitors such as IκBα. In response to proinflammatory cytokines or mitogens, the transduction machinery has recently been characterized, but the activation mechanism upon oxidative stress remains unknown. In the present work, we provide several lines of evidence that NF-κB activation in a T lymphocytic cell line (EL4) by hydrogen peroxide (H2O2) did not involve phosphorylation of the serine residues 32 and 36 in the amino-terminal part of IκBα. Indeed, mutation of Ser32 and Ser36 blocked IL-1β- or PMA-induced NF-κB activation, but had no effect on its activation by H2O2. Although IκBα was phosphorylated upon exposure to H2O2, tyrosine residue 42 and the C-terminal PEST (proline-glutamic acid-serine-threonine) domain played an important role. Indeed, mutation of tyrosine 42 or serine/threonine residues of the PEST domain abolished NF-κB activation by H2O2, while it had no effect on activation by IL-1β or PMA-ionomycin. This H2O2-inducible phosphorylation was not dependent on IκB kinase activation, but could involve casein kinase II, because an inhibitor of this enzyme (5,6-dichloro-1-β-d-ribofuranosyl-benzimidazole) blocks NF-κB activation. H2O2-induced IκBα phosphorylation was followed by its degradation by calpain proteases or through the proteasome. Taken together, our findings suggest that NF-κB activation by H2O2 involves a new mechanism that is totally distinct from those triggered by proinflammatory cytokines or mitogens.

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“…14 -17 Increase in intracellular calcium, most likely at the site of membrane vesicle formation, seems to be a critical step for MP release, but the role of cytoskeleton is not yet fully elucidated (Figure 2). 18 …”

Section: Mp Formation and Release After Cell Activationmentioning

confidence: 99%