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α-Tocopherol at nanomolar concentration protects PC12 cells from hydrogen peroxide-induced death and modulates protein kinase activities.

Zakharova IO, Sokolova TV, Bayunova LV, Vlasova YA, Rychkova MP, Avrova NF - Int J Mol Sci (2012)

Bottom Line: For the first time, the protective effect of α-tocopherol was shown to depend on its concentration in the nanomolar range (1 nM < 10 nM < 100 nM), if the pre-incubation time was 18 h.Nanomolar and micromolar α-tocopherol decreased the number of PC12 cells in late apoptosis induced by H(2)O(2) to the same extent if pre-incubation time was 18 h.The data obtained suggest that inhibition by α-tocopherol in late stage ERK 1/2 and Akt activation induced by H(2)O(2) in PC12 cells makes contribution to its protective effect, while total inhibition of these enzymes is not protective.

View Article: PubMed Central - PubMed

Affiliation: Department of Comparative Neurochemistry, Institute of Evolutionary Physiology and Biochemistry of Russian Academy of Sciences, Thorez avenue, 44, Saint-Petersburg 194223, Russia; E-Mails: zakhar@iephb.ru (I.O.Z.); sokolt1956@mail.ru (T.V.S.); bayunoval@mail.ru (L.V.B.); yousia@mail.ru (Y.A.V.); involved@mail.ru (M.P.R.).

ABSTRACT
The aim of this work was to compare protective and anti-apoptotic effects of α-tocopherol at nanomolar and micromolar concentrations against 0.2 mM H(2)O(2)-induced toxicity in the PC12 neuronal cell line and to reveal protein kinases that contribute to α-tocopherol protective action. The protection by 100 nM α-tocopherol against H(2)O(2)-induced PC12 cell death was pronounced if the time of pre-incubation with α-tocopherol was 3-18 h. For the first time, the protective effect of α-tocopherol was shown to depend on its concentration in the nanomolar range (1 nM < 10 nM < 100 nM), if the pre-incubation time was 18 h. Nanomolar and micromolar α-tocopherol decreased the number of PC12 cells in late apoptosis induced by H(2)O(2) to the same extent if pre-incubation time was 18 h. Immunoblotting data showed that α-tocopherol markedly diminished the time of maximal activation of extracellular signal-regulated kinase 1/2 (ERK 1/2) and protein kinase B (Akt)-induced in PC12 cells by H(2)O(2). Inhibitors of MEK 1/2, PI 3-kinase and protein kinase C (PKC) diminished the protective effect of α-tocopherol against H(2)O(2)-initiated toxicity if the pre-incubation time was long. The modulation of ERK 1/2, Akt and PKC activities appears to participate in the protection by α-tocopherol against H(2)O(2)-induced death of PC12 cells. The data obtained suggest that inhibition by α-tocopherol in late stage ERK 1/2 and Akt activation induced by H(2)O(2) in PC12 cells makes contribution to its protective effect, while total inhibition of these enzymes is not protective.

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Related in: MedlinePlus

The figure shows that the level of pERK 1/2 decreases 1, 3, 7 and 24 h after the exposure of PC12 cells to 100 nM and 100 μM α-T, but there is no change in the total level of ERK 1/2 and Akt and in the level of pAkt in these cells as a result of such exposure. The data of one typical experiment from 3 experiments made are presented. (A) the data were obtained using ECL PLUS (Amersham) to enhance the chemiluminescent signal; (B) SuperSignal West Pico Chemiluminescent Substrate (Pierce, Thermo Scientific) was used as an enhancement solution.
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f7-ijms-13-11543: The figure shows that the level of pERK 1/2 decreases 1, 3, 7 and 24 h after the exposure of PC12 cells to 100 nM and 100 μM α-T, but there is no change in the total level of ERK 1/2 and Akt and in the level of pAkt in these cells as a result of such exposure. The data of one typical experiment from 3 experiments made are presented. (A) the data were obtained using ECL PLUS (Amersham) to enhance the chemiluminescent signal; (B) SuperSignal West Pico Chemiluminescent Substrate (Pierce, Thermo Scientific) was used as an enhancement solution.

Mentions: If we used SuperSignal West Pico Chemiluminescent Substrate (Pierce, Thermo Scientific) as an enhancement solution (Figure 7B), the basal pERK activity was revealed on the blots only in controls, but after PC12 cell exposure to 100 nM and 100 μM α-T for 1, 3, 7 and 24 h, it was practically absent.


α-Tocopherol at nanomolar concentration protects PC12 cells from hydrogen peroxide-induced death and modulates protein kinase activities.

Zakharova IO, Sokolova TV, Bayunova LV, Vlasova YA, Rychkova MP, Avrova NF - Int J Mol Sci (2012)

The figure shows that the level of pERK 1/2 decreases 1, 3, 7 and 24 h after the exposure of PC12 cells to 100 nM and 100 μM α-T, but there is no change in the total level of ERK 1/2 and Akt and in the level of pAkt in these cells as a result of such exposure. The data of one typical experiment from 3 experiments made are presented. (A) the data were obtained using ECL PLUS (Amersham) to enhance the chemiluminescent signal; (B) SuperSignal West Pico Chemiluminescent Substrate (Pierce, Thermo Scientific) was used as an enhancement solution.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3472762&req=5

f7-ijms-13-11543: The figure shows that the level of pERK 1/2 decreases 1, 3, 7 and 24 h after the exposure of PC12 cells to 100 nM and 100 μM α-T, but there is no change in the total level of ERK 1/2 and Akt and in the level of pAkt in these cells as a result of such exposure. The data of one typical experiment from 3 experiments made are presented. (A) the data were obtained using ECL PLUS (Amersham) to enhance the chemiluminescent signal; (B) SuperSignal West Pico Chemiluminescent Substrate (Pierce, Thermo Scientific) was used as an enhancement solution.
Mentions: If we used SuperSignal West Pico Chemiluminescent Substrate (Pierce, Thermo Scientific) as an enhancement solution (Figure 7B), the basal pERK activity was revealed on the blots only in controls, but after PC12 cell exposure to 100 nM and 100 μM α-T for 1, 3, 7 and 24 h, it was practically absent.

Bottom Line: For the first time, the protective effect of α-tocopherol was shown to depend on its concentration in the nanomolar range (1 nM < 10 nM < 100 nM), if the pre-incubation time was 18 h.Nanomolar and micromolar α-tocopherol decreased the number of PC12 cells in late apoptosis induced by H(2)O(2) to the same extent if pre-incubation time was 18 h.The data obtained suggest that inhibition by α-tocopherol in late stage ERK 1/2 and Akt activation induced by H(2)O(2) in PC12 cells makes contribution to its protective effect, while total inhibition of these enzymes is not protective.

View Article: PubMed Central - PubMed

Affiliation: Department of Comparative Neurochemistry, Institute of Evolutionary Physiology and Biochemistry of Russian Academy of Sciences, Thorez avenue, 44, Saint-Petersburg 194223, Russia; E-Mails: zakhar@iephb.ru (I.O.Z.); sokolt1956@mail.ru (T.V.S.); bayunoval@mail.ru (L.V.B.); yousia@mail.ru (Y.A.V.); involved@mail.ru (M.P.R.).

ABSTRACT
The aim of this work was to compare protective and anti-apoptotic effects of α-tocopherol at nanomolar and micromolar concentrations against 0.2 mM H(2)O(2)-induced toxicity in the PC12 neuronal cell line and to reveal protein kinases that contribute to α-tocopherol protective action. The protection by 100 nM α-tocopherol against H(2)O(2)-induced PC12 cell death was pronounced if the time of pre-incubation with α-tocopherol was 3-18 h. For the first time, the protective effect of α-tocopherol was shown to depend on its concentration in the nanomolar range (1 nM < 10 nM < 100 nM), if the pre-incubation time was 18 h. Nanomolar and micromolar α-tocopherol decreased the number of PC12 cells in late apoptosis induced by H(2)O(2) to the same extent if pre-incubation time was 18 h. Immunoblotting data showed that α-tocopherol markedly diminished the time of maximal activation of extracellular signal-regulated kinase 1/2 (ERK 1/2) and protein kinase B (Akt)-induced in PC12 cells by H(2)O(2). Inhibitors of MEK 1/2, PI 3-kinase and protein kinase C (PKC) diminished the protective effect of α-tocopherol against H(2)O(2)-initiated toxicity if the pre-incubation time was long. The modulation of ERK 1/2, Akt and PKC activities appears to participate in the protection by α-tocopherol against H(2)O(2)-induced death of PC12 cells. The data obtained suggest that inhibition by α-tocopherol in late stage ERK 1/2 and Akt activation induced by H(2)O(2) in PC12 cells makes contribution to its protective effect, while total inhibition of these enzymes is not protective.

Show MeSH
Related in: MedlinePlus