Neuronal Differentiation of Neuro 2a Cells by Inhibitors of Cell Cycle Progression, Trichostatin A and Butyrolactone I

Inokoshi, Junji; Katagiri, Masayuki; Arima, Shiho; Tanaka, Haruo; Hayashi, Masahiko; Kim, Young Bae; Furumai, Ryohei; Yoshida, Minoru; Horinouchi, Sueharu; Ōmura, Satoshi

doi:10.1006/bbrc.1999.0316

Cited by 50 publications

(34 citation statements)

References 13 publications

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“…decreased antioxidant capacity (68 -70) including thioredoxin (71) and a shift to a more oxidized state (16). Ctrl H63 and TrxR2 H64 cells were cultured 72 h in the presence of trichostatin A, a specific inhibitor of histone deacetylase, to induce neuronal differentiation (72). This treat- ment induced cell growth arrest and extensive neurite formation to a similar extent in both cell lines, as detected by confocal phase contrast differential interference contrast analysis (not shown).…”

Section: Analysis Of Cell Death Indices In Trxr2-transfected Cells Exmentioning

confidence: 89%

Mitochondrial Thioredoxin System

Patenaude

Murthy

Mirault

2004

Journal of Biological Chemistry

101

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Thioredoxin-2 (Trx2) is a mitochondrial protein-disulfide oxidoreductase essential for control of cell survival during mammalian embryonic development. This suggests that mitochondrial thioredoxin reductase-2 (TrxR2), responsible for reducing oxidized Trx2, may also be a key player in the regulation of mitochondria-dependent apoptosis. With this in mind, we investigated the effects of overexpression of TrxR2, Trx2, or both on mammalian cell responses to various apoptotic inducers. Stable transfectants of mouse Neuro2A cells were generated that overexpressed TrxR2 or an EGFP-TrxR2 fusion protein. EGFPTrxR2 was enzymatically active and was localized in mitochondria. TrxR2 protein level and TrxR activity could be increased up to 6-fold in mitochondria. TrxR2 and EGFP-TrxR2 transfectants showed reduced growth rates as compared with control cells. This growth alteration was not due to cytotoxic effects nor related to changes in basal mitochondrial transmembrane potential (⌬⌿ m ), reactive oxygen species production, or to other mitochondrial antioxidant components such as Trx2, peroxyredoxin-3, MnSOD, GPx1, and glutathione whose levels were not affected by increased TrxR2 activity. In response to various apoptotic inducers, the extent of ⌬⌿ m dissipation, reactive oxygen species induction, caspase activation, and loss of viability were remarkably similar in TrxR2 and control transfectants. Excess TrxR2 did not prevent trichostatin A-mediated neuronal differentiation of Neuro2A cells nor did it protect them against ␤-amyloid neurotoxicity. Neither massive glutathione depletion nor co-transfection of Trx2 and TrxR2 in Neuro2A (mouse), COS-7 (monkey), or HeLa (human) cells revealed any differential cellular resistance to prooxidant or non-oxidant apoptotic stimuli. Our results suggest that neither Trx2 nor TrxR2 gain of function modified the redox regulation of mitochondria-dependent apoptosis in these mammalian cells.A drastic alteration of the mitochondrial redox environment, which includes rapid oxidation of NAD(P)H and glutathione, is one of the earliest events of the mitochondrial pathway of apoptosis (1-3). This phenomenon is associated with dissipation of the mitochondrial transmembrane potential (⌬ m ) and subsequent induction of reactive oxygen species (ROS) 1 generation (4). Onset of mitochondrial membrane permeabilization (MMP), a decisive step in the mitochondrial pathway of apoptosis, is regulated by both pyridine nucleotide (NAD/NADH and NADP ϩ /NADPH) and glutathione (GSSG/GSH) redox equilibrium (5, 6). Protein thiol (sulfhydryl) groups can be oxidized directly or indirectly by ROS, i.e. via GSH oxidation and mixed disulfide formation, such as glutathiolation. For example, specific thiol groups on the adenine nucleotide translocator (ANT), an inner membrane constituent of the mitochondrial permeability transition pore complex, have been implicated in modulating MMP. Oxidation of Cys-56 and crosslinking of Cys-56 to Cys-159 were shown to convert the ADP/ ATP translocase into an opened nonspecific pore, a pr...

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Section: Analysis Of Cell Death Indices In Trxr2-transfected Cells Exmentioning

confidence: 89%

Mitochondrial Thioredoxin System

Patenaude

Murthy

Mirault

2004

Journal of Biological Chemistry

101

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“…It is well known that differentiation and apoptosis represent alternative and often mutually exclusive cell fates (46), and differentiating leukemic cells exhibit resistance to apoptosis induced by cytotoxic drugs (47). In addition, because cell cycle arrest in G 1 is required for leukemic cell maturation, it seemed reasonable to hypothesize that CDKIs, which by themselves can induce differentiation (19,21,48), might enhance HDACI-mediated maturation. However, flavopiridol blocks leukemic cell differentiation by HDACIs (22,23) as well as the phorbol ester phorbol 12-myristate 13-acetate (36).…”

Section: Discussionmentioning

confidence: 99%

Potentiation of the lethality of the histone deacetylase inhibitor LAQ824 by the cyclin-dependent kinase inhibitor roscovitine in human leukemia cells

Rosato

Almenara

Maggio

et al. 2005

Molecular Cancer Therapeutics

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Interactions between the novel histone deacetylase inhibitor LAQ824 and the cyclin-dependent kinase inhibitor roscovitine were examined in human leukemia cells. Pretreatment (24 hours) with a subtoxic concentration of LAQ824 (30 nmol/L) followed by a minimally toxic concentration of roscovitine (10 Mmol/L; 24 hours) resulted in greater than additive effects on apoptosis in U937, Jurkat, and HL-60 human leukemia cells and blasts from three patients with acute myelogenous leukemia. These events were associated with enhanced conformational changes in Bax; mitochondrial release of cytochrome c, Smac/DIABLO, and apoptosis-inducing factor; and a marked increase in caspase activation. LAQ824/ roscovitine -treated cells displayed caspase-dependent down-regulation of p21 CIP1 and Mcl-1 and a pronounced caspase-independent reduction in X-linked inhibitor of apoptosis (XIAP) expression. The lethality of this regimen was significantly attenuated by ectopic expression of XIAP, a nuclear localization signal -defective p21 CIP1 mutant, Mcl-1, and Bcl-2. Combined exposure to LAQ824 and roscovitine resulted in a significant reduction in XIAP mRNA levels and diminished phosphorylation of the carboxyl-terminal domain of RNA polymerase II. Notably, roscovitine blocked LAQ824-mediated differentiation. Finally, LAQ824 and roscovitine individually and in combination triggered an increase in generation of reactive oxygen species; moreover, coadministration of the free radical scavenger N-acetylcysteine prevented LAQ824/roscovitine -mediated mitochondrial injury and apoptosis. Collectively, these findings suggest that combined treatment of human leukemia cells with LAQ824 and roscovitine disrupts maturation and synergistically induces apoptosis, lending further support for an antileukemic strategy combining novel histone deacetylase and cyclin-dependent kinase inhibitors. [Mol Cancer Ther 2005;4(11):1772 -85]

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“…HDAC inhibitors can prevent proliferation and induce differentiation of numerous transformed cell types, including neuroblastoma, erythroleukemia, acute myelogenous leukemia, and carcinomas of the skin, breast, prostate, bladder, lung, colon, and cervix (62)(63)(64)(65)(66)(67). Given the extensive clinical experience with VPA, it may provide a relatively safe, well tested alternative to the use of TSA and trapoxin in the therapy of malignant diseases.…”

Section: Vpa Activates Tcf/lef-dependent Transcription and Synergizesmentioning

confidence: 99%

Histone Deacetylase Is a Direct Target of Valproic Acid, a Potent Anticonvulsant, Mood Stabilizer, and Teratogen

Phiel¹,

Zhang²,

Huang³

et al. 2001

Journal of Biological Chemistry

1,567

1,214

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Valproic acid is widely used to treat epilepsy and bipolar disorder and is also a potent teratogen, but its mechanisms of action in any of these settings are unknown. We report that valproic acid activates Wntdependent gene expression, similar to lithium, the mainstay of therapy for bipolar disorder. Valproic acid, however, acts through a distinct pathway that involves direct inhibition of histone deacetylase (IC 50 for HDAC1 ‫؍‬ 0.4 mM). At therapeutic levels, valproic acid mimics the histone deacetylase inhibitor trichostatin A, causing hyperacetylation of histones in cultured cells. Valproic acid, like trichostatin A, also activates transcription from diverse exogenous and endogenous promoters. Furthermore, valproic acid and trichostatin A have remarkably similar teratogenic effects in vertebrate embryos, while non-teratogenic analogues of valproic acid do not inhibit histone deacetylase and do not activate transcription. Based on these observations, we propose that inhibition of histone deacetylase provides a mechanism for valproic acid-induced birth defects and could also explain the efficacy of valproic acid in the treatment of bipolar disorder.

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Neuronal Differentiation of Neuro 2a Cells by Inhibitors of Cell Cycle Progression, Trichostatin A and Butyrolactone I

Cited by 50 publications

References 13 publications

Mitochondrial Thioredoxin System

Mitochondrial Thioredoxin System

Potentiation of the lethality of the histone deacetylase inhibitor LAQ824 by the cyclin-dependent kinase inhibitor roscovitine in human leukemia cells

Histone Deacetylase Is a Direct Target of Valproic Acid, a Potent Anticonvulsant, Mood Stabilizer, and Teratogen

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