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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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Treatment with CP2 and other TP compounds prevents cholesterol accumulation in HD neurons. A. Intracellular cholesterol levels in striatal neurons from control (C) and HD72 (HD) mice with and without CP2 treatment at different days in culture. Control neurons do not accumulate cholesterol; HD neurons without CP2 treatment accumulate cholesterol to high extent than control neurons (13 DIC). Treatment with CP2 prevented cholesterol accumulation in HD neuron at 13 DIC. At least 15 cells were taken into analysis for each data point. *, p < 0.001. B. Different TP compounds prevent cholesterol accumulation in HD neurons with similar efficiency. Data represent intracellular cholesterol levels in untreated control and HD neurons and neurons treated with 2 μM of different TP compounds on day 13 in culture. Numbers represent relative fluorescence units of filipin staining. At least 10 cells in each experiment were taken into analysis.
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Figure 5: Treatment with CP2 and other TP compounds prevents cholesterol accumulation in HD neurons. A. Intracellular cholesterol levels in striatal neurons from control (C) and HD72 (HD) mice with and without CP2 treatment at different days in culture. Control neurons do not accumulate cholesterol; HD neurons without CP2 treatment accumulate cholesterol to high extent than control neurons (13 DIC). Treatment with CP2 prevented cholesterol accumulation in HD neuron at 13 DIC. At least 15 cells were taken into analysis for each data point. *, p < 0.001. B. Different TP compounds prevent cholesterol accumulation in HD neurons with similar efficiency. Data represent intracellular cholesterol levels in untreated control and HD neurons and neurons treated with 2 μM of different TP compounds on day 13 in culture. Numbers represent relative fluorescence units of filipin staining. At least 10 cells in each experiment were taken into analysis.

Mentions: Since CP2 has been found to restore lipid trafficking in primary striatal neurons expressing mhtt, we next investigated whether CP2 and its analogues could also avert another early cellular defect found in HD neurons, the accumulation of cholesterol [18]. To test this, we plated embryonic (E17) striatal neurons from control and HD72 mice and immediately treated them with 2 μM of different TP compounds. Neurons were kept under continues TP treatment for 13 days, then cells were fixed and intracellular levels of free cholesterol were estimated and compared to untreated neurons using filipin staining. Filipin is an antibiotic that specifically binds free cholesterol and could be visualized under the UV light [26]. Consistent with our previous data, untreated HD72 neurons accumulated significant amounts of cholesterol after 13 days in culture relative to control neurons (Figure 5A, B). In contrast, in HD72 neurons kept in the presence of 2 μM CP2 cholesterol levels did not increase and were similar to control neurons 13 days after plating (Figure 5A, Day 13). Thus, CP2 treatment effectively prevented accumulation of cholesterol caused by mhtt expression.


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 CP2 and other TP compounds prevents cholesterol accumulation in HD neurons. A. Intracellular cholesterol levels in striatal neurons from control (C) and HD72 (HD) mice with and without CP2 treatment at different days in culture. Control neurons do not accumulate cholesterol; HD neurons without CP2 treatment accumulate cholesterol to high extent than control neurons (13 DIC). Treatment with CP2 prevented cholesterol accumulation in HD neuron at 13 DIC. At least 15 cells were taken into analysis for each data point. *, p < 0.001. B. Different TP compounds prevent cholesterol accumulation in HD neurons with similar efficiency. Data represent intracellular cholesterol levels in untreated control and HD neurons and neurons treated with 2 μM of different TP compounds on day 13 in culture. Numbers represent relative fluorescence units of filipin staining. At least 10 cells in each experiment were taken into analysis.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 5: Treatment with CP2 and other TP compounds prevents cholesterol accumulation in HD neurons. A. Intracellular cholesterol levels in striatal neurons from control (C) and HD72 (HD) mice with and without CP2 treatment at different days in culture. Control neurons do not accumulate cholesterol; HD neurons without CP2 treatment accumulate cholesterol to high extent than control neurons (13 DIC). Treatment with CP2 prevented cholesterol accumulation in HD neuron at 13 DIC. At least 15 cells were taken into analysis for each data point. *, p < 0.001. B. Different TP compounds prevent cholesterol accumulation in HD neurons with similar efficiency. Data represent intracellular cholesterol levels in untreated control and HD neurons and neurons treated with 2 μM of different TP compounds on day 13 in culture. Numbers represent relative fluorescence units of filipin staining. At least 10 cells in each experiment were taken into analysis.
Mentions: Since CP2 has been found to restore lipid trafficking in primary striatal neurons expressing mhtt, we next investigated whether CP2 and its analogues could also avert another early cellular defect found in HD neurons, the accumulation of cholesterol [18]. To test this, we plated embryonic (E17) striatal neurons from control and HD72 mice and immediately treated them with 2 μM of different TP compounds. Neurons were kept under continues TP treatment for 13 days, then cells were fixed and intracellular levels of free cholesterol were estimated and compared to untreated neurons using filipin staining. Filipin is an antibiotic that specifically binds free cholesterol and could be visualized under the UV light [26]. Consistent with our previous data, untreated HD72 neurons accumulated significant amounts of cholesterol after 13 days in culture relative to control neurons (Figure 5A, B). In contrast, in HD72 neurons kept in the presence of 2 μM CP2 cholesterol levels did not increase and were similar to control neurons 13 days after plating (Figure 5A, Day 13). Thus, CP2 treatment effectively prevented accumulation of cholesterol caused by mhtt expression.

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