Understanding the cholesterol metabolism-perturbing effects of docosahexaenoic acid by gas chromatography–mass spectrometry targeted metabonomic profiling

Priti Bahety; Thi Hai Van Nguyen; Yanjun Hong; Luqi Zhang; Eric Chun Yong Chan; Pui Lai Rachel Ee

doi:10.1007/s00394-015-1053-4

Understanding the cholesterol metabolism-perturbing effects of docosahexaenoic acid by gas chromatography–mass spectrometry targeted metabonomic profiling

Priti Bahety, Thi Hai Van Nguyen, Yanjun Hong, Luqi Zhang, Eric Chun Yong Chan^*, Pui Lai Rachel Ee

^*Corresponding author for this work

Research output: Contribution to journal › Journal article › peer-review

9 Citations (Scopus)

Abstract

Purpose: Over the past few decades, docosahexaenoic acid (DHA) has gained special attention for management of cholesterol-associated metabolic disorders and neurodegenerative diseases such as Alzheimer’s disease (AD) owing to its neuroprotective, anti-inflammatory and hypolipidemic properties. Several epidemiological studies have reported the effect of DHA in reducing the risk of developing AD by lowering cholesterol. Hypercholesterolemia is a pro-amyloidogenic factor influencing the enzymatic processing of amyloid-β precursor protein (AβPP) to toxic β-amyloid. However, the mechanism by which DHA modulates the cholesterol pathway has not been established. Thus, the objective of this study was to investigate the mechanism of regulation of cholesterol metabolism by DHA in an AβPP₆₉₅ overexpressing AD cell model. Methods: A gas chromatography/mass spectrometry method was developed and validated for the targeted profiling of 11 cholesterol metabolites in DHA-treated Chinese hamster ovary wild-type (CHO-wt) and AβPP₆₉₅ overexpressing (CHO-AβPP₆₉₅) cells. The differential metabolite profiles between DHA- and vehicle-treated groups were further analyzed using fold change values of the ratio of concentration of metabolites in CHO-AβPP₆₉₅ to CHO-wt cells. Effect of DHA on key rate-limiting enzymatic activities within the cholesterol pathway was established using biochemical assays. Results: Our results showed that DHA reduced the levels of key cholesterol anabolites and catabolites in CHO-AβPP₆₉₅ cells as compared to CHO-wt cells. Further enzymatic studies revealed that the cholesterol-lowering effect of DHA was mediated by regulating HMG-CoA reductase and squalene epoxidase enzyme activities. Conclusion: We demonstrate for the first time the dual effects of DHA in inhibiting HMG-CoA reductase and squalene epoxidase and modulating the sterol biosynthesis axis of the cholesterol pathway in AβPP₆₉₅ overexpressing AD. Our novel findings underscore the potential of DHA as a multi-target hypocholesterolemic agent for the prophylaxis of AD and other cholesterol-associated diseases.

Original language	English
Pages (from-to)	29-43
Number of pages	15
Journal	European Journal of Nutrition
Volume	56
Issue number	1
DOIs	https://doi.org/10.1007/s00394-015-1053-4
Publication status	Published - 1 Feb 2017

User-Defined Keywords

Amyloid β-precursor protein (AβPP)
Cholesterol
Docosahexaenoic acid (DHA)
Gas chromatography
HMG-CoA reductase
Metabonomics
Squalene epoxidase

Access to Document

10.1007/s00394-015-1053-4

Cite this

@article{179c963aeacd4bcc8e86aa09a40c0800,

title = "Understanding the cholesterol metabolism-perturbing effects of docosahexaenoic acid by gas chromatography–mass spectrometry targeted metabonomic profiling",

abstract = "Purpose: Over the past few decades, docosahexaenoic acid (DHA) has gained special attention for management of cholesterol-associated metabolic disorders and neurodegenerative diseases such as Alzheimer{\textquoteright}s disease (AD) owing to its neuroprotective, anti-inflammatory and hypolipidemic properties. Several epidemiological studies have reported the effect of DHA in reducing the risk of developing AD by lowering cholesterol. Hypercholesterolemia is a pro-amyloidogenic factor influencing the enzymatic processing of amyloid-β precursor protein (AβPP) to toxic β-amyloid. However, the mechanism by which DHA modulates the cholesterol pathway has not been established. Thus, the objective of this study was to investigate the mechanism of regulation of cholesterol metabolism by DHA in an AβPP695 overexpressing AD cell model. Methods: A gas chromatography/mass spectrometry method was developed and validated for the targeted profiling of 11 cholesterol metabolites in DHA-treated Chinese hamster ovary wild-type (CHO-wt) and AβPP695 overexpressing (CHO-AβPP695) cells. The differential metabolite profiles between DHA- and vehicle-treated groups were further analyzed using fold change values of the ratio of concentration of metabolites in CHO-AβPP695 to CHO-wt cells. Effect of DHA on key rate-limiting enzymatic activities within the cholesterol pathway was established using biochemical assays. Results: Our results showed that DHA reduced the levels of key cholesterol anabolites and catabolites in CHO-AβPP695 cells as compared to CHO-wt cells. Further enzymatic studies revealed that the cholesterol-lowering effect of DHA was mediated by regulating HMG-CoA reductase and squalene epoxidase enzyme activities. Conclusion: We demonstrate for the first time the dual effects of DHA in inhibiting HMG-CoA reductase and squalene epoxidase and modulating the sterol biosynthesis axis of the cholesterol pathway in AβPP695 overexpressing AD. Our novel findings underscore the potential of DHA as a multi-target hypocholesterolemic agent for the prophylaxis of AD and other cholesterol-associated diseases.",

keywords = "Amyloid β-precursor protein (AβPP), Cholesterol, Docosahexaenoic acid (DHA), Gas chromatography, HMG-CoA reductase, Metabonomics, Squalene epoxidase",

author = "Priti Bahety and {Van Nguyen}, {Thi Hai} and Yanjun Hong and Luqi Zhang and Chan, {Eric Chun Yong} and Ee, {Pui Lai Rachel}",

note = "Funding Information: We sincerely thank Associate Professor Gavin S. Dawe, at Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, for providing with CHO-wt and CHO-A?PP695 cells. This work was supported by National University of Singapore???s Graduate Scholarship to PB and National University of Singapore???s Academic Research Funds R-148-000-193-112 to ECYC and R-148-000-150-112 to PLRE.",

year = "2017",

month = feb,

day = "1",

doi = "10.1007/s00394-015-1053-4",

language = "English",

volume = "56",

pages = "29--43",

journal = "European Journal of Nutrition",

issn = "1436-6207",

publisher = "D. Steinkopff-Verlag",

number = "1",

}

TY - JOUR

T1 - Understanding the cholesterol metabolism-perturbing effects of docosahexaenoic acid by gas chromatography–mass spectrometry targeted metabonomic profiling

AU - Bahety, Priti

AU - Van Nguyen, Thi Hai

AU - Hong, Yanjun

AU - Zhang, Luqi

AU - Chan, Eric Chun Yong

AU - Ee, Pui Lai Rachel

N1 - Funding Information: We sincerely thank Associate Professor Gavin S. Dawe, at Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, for providing with CHO-wt and CHO-A?PP695 cells. This work was supported by National University of Singapore???s Graduate Scholarship to PB and National University of Singapore???s Academic Research Funds R-148-000-193-112 to ECYC and R-148-000-150-112 to PLRE.

PY - 2017/2/1

Y1 - 2017/2/1

N2 - Purpose: Over the past few decades, docosahexaenoic acid (DHA) has gained special attention for management of cholesterol-associated metabolic disorders and neurodegenerative diseases such as Alzheimer’s disease (AD) owing to its neuroprotective, anti-inflammatory and hypolipidemic properties. Several epidemiological studies have reported the effect of DHA in reducing the risk of developing AD by lowering cholesterol. Hypercholesterolemia is a pro-amyloidogenic factor influencing the enzymatic processing of amyloid-β precursor protein (AβPP) to toxic β-amyloid. However, the mechanism by which DHA modulates the cholesterol pathway has not been established. Thus, the objective of this study was to investigate the mechanism of regulation of cholesterol metabolism by DHA in an AβPP695 overexpressing AD cell model. Methods: A gas chromatography/mass spectrometry method was developed and validated for the targeted profiling of 11 cholesterol metabolites in DHA-treated Chinese hamster ovary wild-type (CHO-wt) and AβPP695 overexpressing (CHO-AβPP695) cells. The differential metabolite profiles between DHA- and vehicle-treated groups were further analyzed using fold change values of the ratio of concentration of metabolites in CHO-AβPP695 to CHO-wt cells. Effect of DHA on key rate-limiting enzymatic activities within the cholesterol pathway was established using biochemical assays. Results: Our results showed that DHA reduced the levels of key cholesterol anabolites and catabolites in CHO-AβPP695 cells as compared to CHO-wt cells. Further enzymatic studies revealed that the cholesterol-lowering effect of DHA was mediated by regulating HMG-CoA reductase and squalene epoxidase enzyme activities. Conclusion: We demonstrate for the first time the dual effects of DHA in inhibiting HMG-CoA reductase and squalene epoxidase and modulating the sterol biosynthesis axis of the cholesterol pathway in AβPP695 overexpressing AD. Our novel findings underscore the potential of DHA as a multi-target hypocholesterolemic agent for the prophylaxis of AD and other cholesterol-associated diseases.

AB - Purpose: Over the past few decades, docosahexaenoic acid (DHA) has gained special attention for management of cholesterol-associated metabolic disorders and neurodegenerative diseases such as Alzheimer’s disease (AD) owing to its neuroprotective, anti-inflammatory and hypolipidemic properties. Several epidemiological studies have reported the effect of DHA in reducing the risk of developing AD by lowering cholesterol. Hypercholesterolemia is a pro-amyloidogenic factor influencing the enzymatic processing of amyloid-β precursor protein (AβPP) to toxic β-amyloid. However, the mechanism by which DHA modulates the cholesterol pathway has not been established. Thus, the objective of this study was to investigate the mechanism of regulation of cholesterol metabolism by DHA in an AβPP695 overexpressing AD cell model. Methods: A gas chromatography/mass spectrometry method was developed and validated for the targeted profiling of 11 cholesterol metabolites in DHA-treated Chinese hamster ovary wild-type (CHO-wt) and AβPP695 overexpressing (CHO-AβPP695) cells. The differential metabolite profiles between DHA- and vehicle-treated groups were further analyzed using fold change values of the ratio of concentration of metabolites in CHO-AβPP695 to CHO-wt cells. Effect of DHA on key rate-limiting enzymatic activities within the cholesterol pathway was established using biochemical assays. Results: Our results showed that DHA reduced the levels of key cholesterol anabolites and catabolites in CHO-AβPP695 cells as compared to CHO-wt cells. Further enzymatic studies revealed that the cholesterol-lowering effect of DHA was mediated by regulating HMG-CoA reductase and squalene epoxidase enzyme activities. Conclusion: We demonstrate for the first time the dual effects of DHA in inhibiting HMG-CoA reductase and squalene epoxidase and modulating the sterol biosynthesis axis of the cholesterol pathway in AβPP695 overexpressing AD. Our novel findings underscore the potential of DHA as a multi-target hypocholesterolemic agent for the prophylaxis of AD and other cholesterol-associated diseases.

KW - Amyloid β-precursor protein (AβPP)

KW - Cholesterol

KW - Docosahexaenoic acid (DHA)

KW - Gas chromatography

KW - HMG-CoA reductase

KW - Metabonomics

KW - Squalene epoxidase

UR - http://www.scopus.com/inward/record.url?scp=84944619031&partnerID=8YFLogxK

U2 - 10.1007/s00394-015-1053-4

DO - 10.1007/s00394-015-1053-4

M3 - Journal article

C2 - 26428672

AN - SCOPUS:84944619031

SN - 1436-6207

VL - 56

SP - 29

EP - 43

JO - European Journal of Nutrition

JF - European Journal of Nutrition

IS - 1

ER -

Understanding the cholesterol metabolism-perturbing effects of docosahexaenoic acid by gas chromatography–mass spectrometry targeted metabonomic profiling

Abstract

User-Defined Keywords

Access to Document

Other files and links

Fingerprint

Cite this