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Induction of autophagy by a novel small molecule improves aβ pathology and ameliorates cognitive deficits.

Chu C, Zhang X, Ma W, Li L, Wang W, Shang L, Fu P - PLoS ONE (2013)

Bottom Line: GTM-1 modulates autophagy in an Akt-independent and mTOR-independent manner.In addition, we demonstrated that GTM-1 enhances autophagy clearance and reverses the downregulation of autophagy flux by thapsigargin and asparagine.Furthermore, administration of GTM-1 attenuated Aβ pathology and ameliorated cognitive deficits in AD mice.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, The First People's Hospital of Yangzhou, Jiang Su, PR China.

ABSTRACT
Growing evidence has demonstrated a neuroprotective role of autophagy in Alzheimer's disease (AD). Thus, autophagy has been regarded as a potential therapeutic target, attracting increasing interest in pharmaceutical autophagy modulation by small molecules. We designed a two-cycle screening strategy on the basis of imaging high-throughout screening (HTS) and cellular toxicity assay, and have identified a novel autophagy inducer known as GTM-1. We further showed that GTM-1 exhibits dual activities, such as autophagy induction and antagonism against Aβ-oligomer toxicity. GTM-1 modulates autophagy in an Akt-independent and mTOR-independent manner. In addition, we demonstrated that GTM-1 enhances autophagy clearance and reverses the downregulation of autophagy flux by thapsigargin and asparagine. Furthermore, administration of GTM-1 attenuated Aβ pathology and ameliorated cognitive deficits in AD mice.

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Protective effects of GTM-1 in neuroblastoma cells.A–C, MC65 cells were grown in the presence (Tet+) or absence (Tet−) of tetracycline and under Tet− with GTM-1 for 24 hrs, and assessed for: (A) H2O2 production, (B) superoxide production. C, The effect of GTM-1 on the insoluble or soluble Aβ oligomers level were assessed using ELISA in MC65 cells 72 hrs after tetracyline withdrawal (C). Cells incubated with tetracycline (Tet+) were used as a negative control (NC), and cells cultured without tetracycline (Tet−) were used as a positive control (PC). D, SH-SY5Y cells were incubated with the indicated compounds for 24 h. The cell viability was assayed using the MTT assay. Aβ, Aβ42 (30 µM), 3-MA (10 µM), spautin-1 (10 µM), GTM-1 (20 µM). Cells treated with vehicle (0.1% DMSO) were used as a negative control (NC). E, MC65 cells were grown in the presence (Tet+) or absence (Tet−) of tetracycline and under Tet− with the indicated compounds for 24 hrs, and the cell viability was assessed using the MTT assay. 3-MA (10 µM), spautin-1 (10 µM), GTM-1 (20 µM). Cells cultured in the presence of tetracycline (Tet+) were used as a negative control (NC). Stars indicated significant differences between the model group and control or treatment groups for specific time points. *P<0.05, **P<0.01.
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pone-0065367-g003: Protective effects of GTM-1 in neuroblastoma cells.A–C, MC65 cells were grown in the presence (Tet+) or absence (Tet−) of tetracycline and under Tet− with GTM-1 for 24 hrs, and assessed for: (A) H2O2 production, (B) superoxide production. C, The effect of GTM-1 on the insoluble or soluble Aβ oligomers level were assessed using ELISA in MC65 cells 72 hrs after tetracyline withdrawal (C). Cells incubated with tetracycline (Tet+) were used as a negative control (NC), and cells cultured without tetracycline (Tet−) were used as a positive control (PC). D, SH-SY5Y cells were incubated with the indicated compounds for 24 h. The cell viability was assayed using the MTT assay. Aβ, Aβ42 (30 µM), 3-MA (10 µM), spautin-1 (10 µM), GTM-1 (20 µM). Cells treated with vehicle (0.1% DMSO) were used as a negative control (NC). E, MC65 cells were grown in the presence (Tet+) or absence (Tet−) of tetracycline and under Tet− with the indicated compounds for 24 hrs, and the cell viability was assessed using the MTT assay. 3-MA (10 µM), spautin-1 (10 µM), GTM-1 (20 µM). Cells cultured in the presence of tetracycline (Tet+) were used as a negative control (NC). Stars indicated significant differences between the model group and control or treatment groups for specific time points. *P<0.05, **P<0.01.

Mentions: Consistent with these reports, deprivation of tetracycline (Tet−) from the MC65 culture medium caused an increase in the intracellular H2O2 levels to 150% and an increase in super oxidation to 270% (Fig. 3A, 3B). In contrast, treatment with GTM-1 (100 µM) blocked the upregulation of super oxidation levels by deprivation of tetracycline and greatly reduced intracellular hydrogen peroxide levels (Fig. 3A, 3B). Specifically, MC65 cells grown in the presence of tetracycline (Tet+) were used as a control, and in all instances, the measurement of Tet+ MC65 cells was considered 100% and was used as a reference to which all other treatments were compared.


Induction of autophagy by a novel small molecule improves aβ pathology and ameliorates cognitive deficits.

Chu C, Zhang X, Ma W, Li L, Wang W, Shang L, Fu P - PLoS ONE (2013)

Protective effects of GTM-1 in neuroblastoma cells.A–C, MC65 cells were grown in the presence (Tet+) or absence (Tet−) of tetracycline and under Tet− with GTM-1 for 24 hrs, and assessed for: (A) H2O2 production, (B) superoxide production. C, The effect of GTM-1 on the insoluble or soluble Aβ oligomers level were assessed using ELISA in MC65 cells 72 hrs after tetracyline withdrawal (C). Cells incubated with tetracycline (Tet+) were used as a negative control (NC), and cells cultured without tetracycline (Tet−) were used as a positive control (PC). D, SH-SY5Y cells were incubated with the indicated compounds for 24 h. The cell viability was assayed using the MTT assay. Aβ, Aβ42 (30 µM), 3-MA (10 µM), spautin-1 (10 µM), GTM-1 (20 µM). Cells treated with vehicle (0.1% DMSO) were used as a negative control (NC). E, MC65 cells were grown in the presence (Tet+) or absence (Tet−) of tetracycline and under Tet− with the indicated compounds for 24 hrs, and the cell viability was assessed using the MTT assay. 3-MA (10 µM), spautin-1 (10 µM), GTM-1 (20 µM). Cells cultured in the presence of tetracycline (Tet+) were used as a negative control (NC). Stars indicated significant differences between the model group and control or treatment groups for specific time points. *P<0.05, **P<0.01.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3672196&req=5

pone-0065367-g003: Protective effects of GTM-1 in neuroblastoma cells.A–C, MC65 cells were grown in the presence (Tet+) or absence (Tet−) of tetracycline and under Tet− with GTM-1 for 24 hrs, and assessed for: (A) H2O2 production, (B) superoxide production. C, The effect of GTM-1 on the insoluble or soluble Aβ oligomers level were assessed using ELISA in MC65 cells 72 hrs after tetracyline withdrawal (C). Cells incubated with tetracycline (Tet+) were used as a negative control (NC), and cells cultured without tetracycline (Tet−) were used as a positive control (PC). D, SH-SY5Y cells were incubated with the indicated compounds for 24 h. The cell viability was assayed using the MTT assay. Aβ, Aβ42 (30 µM), 3-MA (10 µM), spautin-1 (10 µM), GTM-1 (20 µM). Cells treated with vehicle (0.1% DMSO) were used as a negative control (NC). E, MC65 cells were grown in the presence (Tet+) or absence (Tet−) of tetracycline and under Tet− with the indicated compounds for 24 hrs, and the cell viability was assessed using the MTT assay. 3-MA (10 µM), spautin-1 (10 µM), GTM-1 (20 µM). Cells cultured in the presence of tetracycline (Tet+) were used as a negative control (NC). Stars indicated significant differences between the model group and control or treatment groups for specific time points. *P<0.05, **P<0.01.
Mentions: Consistent with these reports, deprivation of tetracycline (Tet−) from the MC65 culture medium caused an increase in the intracellular H2O2 levels to 150% and an increase in super oxidation to 270% (Fig. 3A, 3B). In contrast, treatment with GTM-1 (100 µM) blocked the upregulation of super oxidation levels by deprivation of tetracycline and greatly reduced intracellular hydrogen peroxide levels (Fig. 3A, 3B). Specifically, MC65 cells grown in the presence of tetracycline (Tet+) were used as a control, and in all instances, the measurement of Tet+ MC65 cells was considered 100% and was used as a reference to which all other treatments were compared.

Bottom Line: GTM-1 modulates autophagy in an Akt-independent and mTOR-independent manner.In addition, we demonstrated that GTM-1 enhances autophagy clearance and reverses the downregulation of autophagy flux by thapsigargin and asparagine.Furthermore, administration of GTM-1 attenuated Aβ pathology and ameliorated cognitive deficits in AD mice.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, The First People's Hospital of Yangzhou, Jiang Su, PR China.

ABSTRACT
Growing evidence has demonstrated a neuroprotective role of autophagy in Alzheimer's disease (AD). Thus, autophagy has been regarded as a potential therapeutic target, attracting increasing interest in pharmaceutical autophagy modulation by small molecules. We designed a two-cycle screening strategy on the basis of imaging high-throughout screening (HTS) and cellular toxicity assay, and have identified a novel autophagy inducer known as GTM-1. We further showed that GTM-1 exhibits dual activities, such as autophagy induction and antagonism against Aβ-oligomer toxicity. GTM-1 modulates autophagy in an Akt-independent and mTOR-independent manner. In addition, we demonstrated that GTM-1 enhances autophagy clearance and reverses the downregulation of autophagy flux by thapsigargin and asparagine. Furthermore, administration of GTM-1 attenuated Aβ pathology and ameliorated cognitive deficits in AD mice.

Show MeSH
Related in: MedlinePlus