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Tricyclic pyrone compounds prevent aggregation and reverse cellular phenotypes caused by expression of mutant huntingtin protein in striatal neurons.

Trushina E, Rana S, McMurray CT, Hua DH - BMC Neurosci (2009)

Bottom Line: Most data suggest that polyglutamine-mediated aggregation associated with expression of mutant huntingtin protein (mhtt) contributes to the pathology.Suppression of aggregation is accepted as one of the markers of successful therapeutic approaches.TP compounds effectively inhibit aggregation caused by mhtt in neurons and glial cells.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemistry, CBC Building, Kansas State University, Manhattan, KS 66506, USA. trushina.eugenia@mayo.edu

ABSTRACT

Background: Huntington's disease (HD) is a progressive neurodegenerative disorder caused by a CAG repeat expansion mutation in the coding region of a novel gene. The mechanism of HD is unknown. Most data suggest that polyglutamine-mediated aggregation associated with expression of mutant huntingtin protein (mhtt) contributes to the pathology. However, recent studies have identified early cellular dysfunctions that preclude aggregate formation. Suppression of aggregation is accepted as one of the markers of successful therapeutic approaches. Previously, we demonstrated that tricyclic pyrone (TP) compounds efficiently inhibited formation of amyloid-beta (Abeta) aggregates in cell and mouse models representing Alzheimer's Disease (AD). In the present study, we aimed to determine whether TP compounds could prevent aggregation and restore early cellular defects in primary embryonic striatal neurons from animal model representing HD.

Results: TP compounds effectively inhibit aggregation caused by mhtt in neurons and glial cells. Treatment with TP compounds also alleviated cholesterol accumulation and restored clathrin-independent endocytosis in HD neurons.

Conclusion: We have found that TP compounds not only blocked mhtt-induced aggregation, but also alleviated early cellular dysfunctions that preclude aggregate formation. Our data suggest TP molecules may be used as lead compounds for prevention or treatment of multiple neurodegenerative diseases including HD and AD.

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Related in: MedlinePlus

Treatment with TP compounds at low concentrations is not toxic for primary neuronal cultures. A. Survival of primary striatal neurons from control mice treated with different concentrations of CP2. Days in culture (DIC) and CP2 concentrations are indicated. Images were acquired using LSM 510 confocal microscope with 63 × or 100 × oil DIC lenses (1.4 na). Scale bars, 20 um. B. Lethal dose at which 50% of the neurons died (LD50) for all three TP compounds was estimated at day 6 after plating using LIVE/DEAD assay.
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Figure 2: Treatment with TP compounds at low concentrations is not toxic for primary neuronal cultures. A. Survival of primary striatal neurons from control mice treated with different concentrations of CP2. Days in culture (DIC) and CP2 concentrations are indicated. Images were acquired using LSM 510 confocal microscope with 63 × or 100 × oil DIC lenses (1.4 na). Scale bars, 20 um. B. Lethal dose at which 50% of the neurons died (LD50) for all three TP compounds was estimated at day 6 after plating using LIVE/DEAD assay.

Mentions: Effective pharmacological compounds must be non-toxic to cells. To evaluate the toxicity of TP compounds, primary embryonic (E17) striatal neurons from FVB control mice were cultured and treated next day after plating with 0, 2, 5, 10, 20 and 40 μM of different TPs. Cells were kept under these conditions for 13 days. Every other day, the neuronal morphology and the extent of cell death were evaluated by imaging of five randomly selected fields (Figure 2A). For all TP compounds tested, concentrations below 5 μM did not cause significant cell death for up to 13 days in culture (Figure 2A, 2 μM). About 60% of neurons remain healthy and preserve their morphology. However, concentrations above 5 μM effectively killed cells in less than 7 days (Figure 2A, 40 μM). At day 6 in culture, for each TP compound, we determined the lethal dose at which 50% of the cells died (LD50) (Figure 2B). The results suggested concentrations between 2 and 5 μM were least toxic for all TPs tested. Survival of HD neurons in response to TP treatments did not differ from control cells (data not shown). Thus, we used these conditions in the following experiments.


Tricyclic pyrone compounds prevent aggregation and reverse cellular phenotypes caused by expression of mutant huntingtin protein in striatal neurons.

Trushina E, Rana S, McMurray CT, Hua DH - BMC Neurosci (2009)

Treatment with TP compounds at low concentrations is not toxic for primary neuronal cultures. A. Survival of primary striatal neurons from control mice treated with different concentrations of CP2. Days in culture (DIC) and CP2 concentrations are indicated. Images were acquired using LSM 510 confocal microscope with 63 × or 100 × oil DIC lenses (1.4 na). Scale bars, 20 um. B. Lethal dose at which 50% of the neurons died (LD50) for all three TP compounds was estimated at day 6 after plating using LIVE/DEAD assay.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2719645&req=5

Figure 2: Treatment with TP compounds at low concentrations is not toxic for primary neuronal cultures. A. Survival of primary striatal neurons from control mice treated with different concentrations of CP2. Days in culture (DIC) and CP2 concentrations are indicated. Images were acquired using LSM 510 confocal microscope with 63 × or 100 × oil DIC lenses (1.4 na). Scale bars, 20 um. B. Lethal dose at which 50% of the neurons died (LD50) for all three TP compounds was estimated at day 6 after plating using LIVE/DEAD assay.
Mentions: Effective pharmacological compounds must be non-toxic to cells. To evaluate the toxicity of TP compounds, primary embryonic (E17) striatal neurons from FVB control mice were cultured and treated next day after plating with 0, 2, 5, 10, 20 and 40 μM of different TPs. Cells were kept under these conditions for 13 days. Every other day, the neuronal morphology and the extent of cell death were evaluated by imaging of five randomly selected fields (Figure 2A). For all TP compounds tested, concentrations below 5 μM did not cause significant cell death for up to 13 days in culture (Figure 2A, 2 μM). About 60% of neurons remain healthy and preserve their morphology. However, concentrations above 5 μM effectively killed cells in less than 7 days (Figure 2A, 40 μM). At day 6 in culture, for each TP compound, we determined the lethal dose at which 50% of the cells died (LD50) (Figure 2B). The results suggested concentrations between 2 and 5 μM were least toxic for all TPs tested. Survival of HD neurons in response to TP treatments did not differ from control cells (data not shown). Thus, we used these conditions in the following experiments.

Bottom Line: Most data suggest that polyglutamine-mediated aggregation associated with expression of mutant huntingtin protein (mhtt) contributes to the pathology.Suppression of aggregation is accepted as one of the markers of successful therapeutic approaches.TP compounds effectively inhibit aggregation caused by mhtt in neurons and glial cells.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemistry, CBC Building, Kansas State University, Manhattan, KS 66506, USA. trushina.eugenia@mayo.edu

ABSTRACT

Background: Huntington's disease (HD) is a progressive neurodegenerative disorder caused by a CAG repeat expansion mutation in the coding region of a novel gene. The mechanism of HD is unknown. Most data suggest that polyglutamine-mediated aggregation associated with expression of mutant huntingtin protein (mhtt) contributes to the pathology. However, recent studies have identified early cellular dysfunctions that preclude aggregate formation. Suppression of aggregation is accepted as one of the markers of successful therapeutic approaches. Previously, we demonstrated that tricyclic pyrone (TP) compounds efficiently inhibited formation of amyloid-beta (Abeta) aggregates in cell and mouse models representing Alzheimer's Disease (AD). In the present study, we aimed to determine whether TP compounds could prevent aggregation and restore early cellular defects in primary embryonic striatal neurons from animal model representing HD.

Results: TP compounds effectively inhibit aggregation caused by mhtt in neurons and glial cells. Treatment with TP compounds also alleviated cholesterol accumulation and restored clathrin-independent endocytosis in HD neurons.

Conclusion: We have found that TP compounds not only blocked mhtt-induced aggregation, but also alleviated early cellular dysfunctions that preclude aggregate formation. Our data suggest TP molecules may be used as lead compounds for prevention or treatment of multiple neurodegenerative diseases including HD and AD.

Show MeSH
Related in: MedlinePlus