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EGCG-mediated autophagy flux has a neuroprotection effect via a class III histone deacetylase in primary neuron cells.

Lee JH, Moon JH, Kim SW, Jeong JK, Nazim UM, Lee YJ, Seol JW, Park SY - Oncotarget (2015)

Bottom Line: The results showed that EGCG protects the neuronal cells against human prion protein-induced damage through inhibiting Bax and cytochrome c translocation and autophagic pathways by increasing LC3-II and reducing and blocking p62 by using ATG5 small interfering (si) RNA and autophagy inhibitors.We further demonstrated that the neuroprotective effects of EGCG were exhibited by a class III histone deacetylase; sirt1 activation and the neuroprotective effects attenuated by sirt1 inactivation using sirt1 siRNA and sirtinol.We demonstrated that EGCG activated the autophagic pathways by inducing sirt1, and had protective effects against human prion protein-induced neuronal cell toxicity.

View Article: PubMed Central - PubMed

Affiliation: Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Jeonju, Jeonbuk, South Korea.

ABSTRACT
Prion diseases caused by aggregated misfolded prion protein (PrP) are transmissible neurodegenerative disorders that occur in both humans and animals. Epigallocatechin-3-gallate (EGCG) has preventive effects on prion disease; however, the mechanisms related to preventing prion diseases are unclear. We investigated whether EGCG, the main polyphenol in green tea, prevents neuron cell damage induced by the human prion protein. We also studied the neuroprotective mechanisms and proper signals mediated by EGCG. The results showed that EGCG protects the neuronal cells against human prion protein-induced damage through inhibiting Bax and cytochrome c translocation and autophagic pathways by increasing LC3-II and reducing and blocking p62 by using ATG5 small interfering (si) RNA and autophagy inhibitors. We further demonstrated that the neuroprotective effects of EGCG were exhibited by a class III histone deacetylase; sirt1 activation and the neuroprotective effects attenuated by sirt1 inactivation using sirt1 siRNA and sirtinol. We demonstrated that EGCG activated the autophagic pathways by inducing sirt1, and had protective effects against human prion protein-induced neuronal cell toxicity. These results suggest that EGCG may be a therapeutic agent for treatment of neurodegenerative disorders including prion diseases.

No MeSH data available.


Related in: MedlinePlus

EGCG increases the induction of autophagyThe primary neuron cells were treated with 1, 2.5, 5, 10 μM of EGCG for 30 h. Western blot for LC3-II, and p62 proteins was analyzed from primary neuron cells. Beta-actin was used as a loading control A. The cells were immunostained with p62 antibody (green) and observed in fluorescent view. Primary neuron cells were pretreated with 10 μM of EGCG in presence of autophagy inhibitor (3MA and wortmannin) for 30 h and western blot for LC3-II and p62 proteins was analyzed B. SH-SY5Y cells were treated with 2.5, 5, or 10 μM EGCG for 30 hr. Western blot for LC3-II, and p62 proteins was conducted with SH-SY5Y cells. Beta-actin was used as the loading control C. SH-SY5Y cells were analyzed by immunocytochemistry for p62 D. The cells were immunostained with p62 antibody (green) and observed in fluorescent view. SH-SY5Y cells were pretreated with 10 μM of EGCG in the presence of autophagy inhibitors (3MA or wortmannin) for 1 hr and then exposed to 50 μM PrP (106-126) for 36 h. Cell viability was measured by the Annexin V assay E, F. SH-SY5Y cells were treated as described in Figure 3A and Western blot for the LC3-II and p62 proteins was analyzed G. Bars indicate mean ± standard error (n = 4). *p < 0.05, **p < 0.01, significant differences between control and each treatment group, and #p < 0.01; significantly different when compared with PrP (106-126)-treated group.
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Figure 3: EGCG increases the induction of autophagyThe primary neuron cells were treated with 1, 2.5, 5, 10 μM of EGCG for 30 h. Western blot for LC3-II, and p62 proteins was analyzed from primary neuron cells. Beta-actin was used as a loading control A. The cells were immunostained with p62 antibody (green) and observed in fluorescent view. Primary neuron cells were pretreated with 10 μM of EGCG in presence of autophagy inhibitor (3MA and wortmannin) for 30 h and western blot for LC3-II and p62 proteins was analyzed B. SH-SY5Y cells were treated with 2.5, 5, or 10 μM EGCG for 30 hr. Western blot for LC3-II, and p62 proteins was conducted with SH-SY5Y cells. Beta-actin was used as the loading control C. SH-SY5Y cells were analyzed by immunocytochemistry for p62 D. The cells were immunostained with p62 antibody (green) and observed in fluorescent view. SH-SY5Y cells were pretreated with 10 μM of EGCG in the presence of autophagy inhibitors (3MA or wortmannin) for 1 hr and then exposed to 50 μM PrP (106-126) for 36 h. Cell viability was measured by the Annexin V assay E, F. SH-SY5Y cells were treated as described in Figure 3A and Western blot for the LC3-II and p62 proteins was analyzed G. Bars indicate mean ± standard error (n = 4). *p < 0.05, **p < 0.01, significant differences between control and each treatment group, and #p < 0.01; significantly different when compared with PrP (106-126)-treated group.

Mentions: First, we examined whether EGCG induces autophagy in primary neuron cells. LC3-II and p62 expression levels were detected using a specific antibody in a Western blot analysis. The primary neuron cells were treated with EGCG at concentrations of 1, 2.5, 5, or 10 μM for 24hr. EGCG increased LC3-II expression levels but decreased p62 levels (Figure 3A)


EGCG-mediated autophagy flux has a neuroprotection effect via a class III histone deacetylase in primary neuron cells.

Lee JH, Moon JH, Kim SW, Jeong JK, Nazim UM, Lee YJ, Seol JW, Park SY - Oncotarget (2015)

EGCG increases the induction of autophagyThe primary neuron cells were treated with 1, 2.5, 5, 10 μM of EGCG for 30 h. Western blot for LC3-II, and p62 proteins was analyzed from primary neuron cells. Beta-actin was used as a loading control A. The cells were immunostained with p62 antibody (green) and observed in fluorescent view. Primary neuron cells were pretreated with 10 μM of EGCG in presence of autophagy inhibitor (3MA and wortmannin) for 30 h and western blot for LC3-II and p62 proteins was analyzed B. SH-SY5Y cells were treated with 2.5, 5, or 10 μM EGCG for 30 hr. Western blot for LC3-II, and p62 proteins was conducted with SH-SY5Y cells. Beta-actin was used as the loading control C. SH-SY5Y cells were analyzed by immunocytochemistry for p62 D. The cells were immunostained with p62 antibody (green) and observed in fluorescent view. SH-SY5Y cells were pretreated with 10 μM of EGCG in the presence of autophagy inhibitors (3MA or wortmannin) for 1 hr and then exposed to 50 μM PrP (106-126) for 36 h. Cell viability was measured by the Annexin V assay E, F. SH-SY5Y cells were treated as described in Figure 3A and Western blot for the LC3-II and p62 proteins was analyzed G. Bars indicate mean ± standard error (n = 4). *p < 0.05, **p < 0.01, significant differences between control and each treatment group, and #p < 0.01; significantly different when compared with PrP (106-126)-treated group.
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Figure 3: EGCG increases the induction of autophagyThe primary neuron cells were treated with 1, 2.5, 5, 10 μM of EGCG for 30 h. Western blot for LC3-II, and p62 proteins was analyzed from primary neuron cells. Beta-actin was used as a loading control A. The cells were immunostained with p62 antibody (green) and observed in fluorescent view. Primary neuron cells were pretreated with 10 μM of EGCG in presence of autophagy inhibitor (3MA and wortmannin) for 30 h and western blot for LC3-II and p62 proteins was analyzed B. SH-SY5Y cells were treated with 2.5, 5, or 10 μM EGCG for 30 hr. Western blot for LC3-II, and p62 proteins was conducted with SH-SY5Y cells. Beta-actin was used as the loading control C. SH-SY5Y cells were analyzed by immunocytochemistry for p62 D. The cells were immunostained with p62 antibody (green) and observed in fluorescent view. SH-SY5Y cells were pretreated with 10 μM of EGCG in the presence of autophagy inhibitors (3MA or wortmannin) for 1 hr and then exposed to 50 μM PrP (106-126) for 36 h. Cell viability was measured by the Annexin V assay E, F. SH-SY5Y cells were treated as described in Figure 3A and Western blot for the LC3-II and p62 proteins was analyzed G. Bars indicate mean ± standard error (n = 4). *p < 0.05, **p < 0.01, significant differences between control and each treatment group, and #p < 0.01; significantly different when compared with PrP (106-126)-treated group.
Mentions: First, we examined whether EGCG induces autophagy in primary neuron cells. LC3-II and p62 expression levels were detected using a specific antibody in a Western blot analysis. The primary neuron cells were treated with EGCG at concentrations of 1, 2.5, 5, or 10 μM for 24hr. EGCG increased LC3-II expression levels but decreased p62 levels (Figure 3A)

Bottom Line: The results showed that EGCG protects the neuronal cells against human prion protein-induced damage through inhibiting Bax and cytochrome c translocation and autophagic pathways by increasing LC3-II and reducing and blocking p62 by using ATG5 small interfering (si) RNA and autophagy inhibitors.We further demonstrated that the neuroprotective effects of EGCG were exhibited by a class III histone deacetylase; sirt1 activation and the neuroprotective effects attenuated by sirt1 inactivation using sirt1 siRNA and sirtinol.We demonstrated that EGCG activated the autophagic pathways by inducing sirt1, and had protective effects against human prion protein-induced neuronal cell toxicity.

View Article: PubMed Central - PubMed

Affiliation: Biosafety Research Institute, College of Veterinary Medicine, Chonbuk National University, Jeonju, Jeonbuk, South Korea.

ABSTRACT
Prion diseases caused by aggregated misfolded prion protein (PrP) are transmissible neurodegenerative disorders that occur in both humans and animals. Epigallocatechin-3-gallate (EGCG) has preventive effects on prion disease; however, the mechanisms related to preventing prion diseases are unclear. We investigated whether EGCG, the main polyphenol in green tea, prevents neuron cell damage induced by the human prion protein. We also studied the neuroprotective mechanisms and proper signals mediated by EGCG. The results showed that EGCG protects the neuronal cells against human prion protein-induced damage through inhibiting Bax and cytochrome c translocation and autophagic pathways by increasing LC3-II and reducing and blocking p62 by using ATG5 small interfering (si) RNA and autophagy inhibitors. We further demonstrated that the neuroprotective effects of EGCG were exhibited by a class III histone deacetylase; sirt1 activation and the neuroprotective effects attenuated by sirt1 inactivation using sirt1 siRNA and sirtinol. We demonstrated that EGCG activated the autophagic pathways by inducing sirt1, and had protective effects against human prion protein-induced neuronal cell toxicity. These results suggest that EGCG may be a therapeutic agent for treatment of neurodegenerative disorders including prion diseases.

No MeSH data available.


Related in: MedlinePlus