Upload
others
View
2
Download
0
Embed Size (px)
Citation preview
Nutrigenetics: What Does the Future Hold?Peter J Jones, PhD
Richardson Centre for Functional Foods and Nutraceuticals
Departments of Human Nutritional Sciences and Food Sciences
University of Manitoba, Winnipeg, Manitoba, Canada
ABIC Meeting
Winnipeg, Manitoba
September 26th, 2017
Sept 26th, 2017
Objectives
• Explore whether genetic factors play a role in explaining the variability of responsiveness of disease risk related biomarkers
• Case studies: plant sterols/ dairy consumption
• Consider whether sufficient evidence exists for development of “personalized nutrition” platforms
Case Study: Plant sterols as natural inhibitors of
cholesterol absorption
Average daily plant sterol intake of adults
150 - 400 mg/day
Major food sources:
• fruits and vegetables
• fat and oils
• bread and cereals
• nuts
* International Atherosclerosis Society, 2003; NCEP III Expert Panel, JAMA 2001, EAS 2014
Recommended intake of
plant sterol-enriched foods
for a significant
cholesterol-lowering effect
2 g/day*
Plant sterol/ stanol meta-analyses results show
high variability between trials
Demonty et al. J Nutr 2009 Musa-Veloso et al. PLEFA 2011
Maximal average LDL-C lowering,
PSa vs PSe:17.3 vs 8.4%*
Pooled LDL-C reduction,2.15 g/d
-8.8% CV =(9.4, 8.3)
84 trials, 141 trial arms
114 trials, 182 trial arms
Large variability exists in LDL-C response to
plant sterols within trials
Rideout et al Lipids Health Dis 2009
Healthy individuals were given 2 g/d plant sterols for 4 wksconsumed under supervision
Large variability exists in LDL-C response to
plant sterols within trials
Rideout et al Lipids Health Dis 2009
Healthy individuals were given 2 g/d plant sterols for 4 wksconsumed under supervision
Is response to plant sterols repeatable?
Percentage Reduction Low-Density Lipoprotein
Cholesterol Compared Control
R2 = 0.7168
-30
-20
-10
0
10
20
30
40
50
-30 -20 -10 0 10 20 30 40 50
Sterol Intake Phase 1
(% Reduction)
Ste
ro
l In
ta
ke
Ph
as
e 2
(%
Re
du
ctio
n)
Percentage Reduction in Total Cholesterol
Compared to Control
R2 = 0.6298
-20
-10
0
10
20
30
40
-20 -10 0 10 20 30 40
Sterol Intake Phase 1
(% Reduction)
Ste
ro
l In
ta
ke
Ph
as
e 2
(%
Re
du
ctio
n)
Rudkowska I, Abumweis SS, Nicolle C, Jones PJ. Association between non-responsiveness to plant sterol intervention and polymorphisms in cholesterol metabolism genes: A case-control study. Appl Physiol Nutr Metab 2008;33:728-34.
Plant sterol response is a phenotype
Objective: Are genetics associated with
cholesterol metabolism predictive of
cholesterol lowering in response to
plant sterol consumption ?
Collaborator: David Baer, USDA, Beltsville
Dual center (Winnipeg, Beltsville), randomized, crossover, single blinded, placebo controlled design
Plant sterol study design
Mackay et al AJCN 2015a
N = 130 65
Lathosterol/cholesterol ratio and LDL-C
response to plant sterol consumption
Low L/C ratio-0.29 ± 0.05 mmol/L, p<0.0001
High L/C ratio-0.04 ± 0.07 mmol/L, p=0.4904
-1.5
-1.0
-0.5
0.0
0.5
1.0
L
DL
-c (
mm
ol/
L)
High L/C ratio=Low L/C ratio= Mackay et al AJCN 2015a
Gene
SNP
Type of SNP Variation Minor allelic frequency Function of gene
ABCA1 ATP-binding cassette, sub-family A (ABC1), member 1 Cholesterol efflux pump in the cellular lipid removal pathway.
rs2230808 NS - missense C to T T=0.410
rs2066714 NS - missense T to C C=0.366
ABCG5 ATP-binding cassette, sub-family G (WHITE), member 5 Half-transporter (with ABCG8) that promotes intestinal and biliary
excretion of sterols.rs6720173 NS - missense G to C C=0.211
rs6756629 NS - missense G to A A=0.074
rs2278356 3’-UTR A to C C=0.403
rs11887534 Near gene-5’ G to C C=0.065
ABCG8 ATP-binding cassette, sub-family G (WHITE), member 8 Half-transporter (with ABCG5) that promotes intestinal and biliary
excretion of sterols.rs4148211 NS - missense A to G G=0.441
rs4148217 NS - missense C to A A=0.218
rs6544718 NS - missense C to T T=0.106
CETP Cholesteryl ester transfer protein Facilitates the transport of cholesteryl esters and triglycerides between the
lipoproteinsrs5882 NS - missense A to G G=0.448
CYP7A1 Cholesterol 7 alpha-hydroxylase The rate-limiting enzyme in the synthesis of bile acid in the classic
pathway.rs3808607 Near gene-5’ T to G G=0.450
DHCR7 7-dehydrocholesterol reductase Enzyme which catalyzes the conversion of 7-dehydrocholesterol to
cholesterol.rs760241 NS - missense G to A A=0.179
LDLR low density lipoprotein receptor A cell surface protein involved in receptor-mediated endocytosis.
rs688 Synonymous A to G G=0.280
LSS Lanosterol synthase The protein encoded by this gene catalyzes the conversion of (S)-2,3
oxidosqualene to lanosterol.rs2839158 NS - missense C to T T=0.137
rs34115287 NS - missense T to C C=0.136
PCSK9 Proprotein convertase subtilisin/kexin type 9 A convertase belonging to the proteinase K subfamily which induces
LDLR degradationrs562556 NS - missense A to G G=0.148
SCAP SREBF chaperone a protein with a sterol sensing domain which is involved in SREBFs
regulation rs12487736 NS - missense C to T T=0.476
SREBF2 Sterol regulatory element binding transcription factor 2 Transcription factor that controls cholesterol homeostasis by stimulating
transcription of sterol-regulated genesrs2228314 NS - missense G to C C=0.366
rs2228313 NS - missense G to C C=0.066
ApoE variant Ε2 Ε3 Ε4 Apolipoprotein E is a glycoprotein present in human plasma; ApoE is
associated with triglyceride-rich lipoproteins (chylomicrons and VLDLs)
and HDL.Typical
frequency*
7.9% 78.6% 13.5%
APOE isoform and rs38038607 in CYP7A1
on LDL-C response to plant sterols
-1.5
-1.0
-0.5
0.0
0.5
1.0
L
DL
-c (
mm
ol/
L)
T/T=G/T=G/G=
ε2 ε3 ε4
MacKay et al AJCN 2015b
Canada’s Food Guiderecommends 2-3 servings/d of low-fat milk and alternatives
Unique fatty acid profile
Variability exists across studies in response of cholesterol metabolism to dairy consumption
Results for butter are consistent (Tholstrup et al. 2004, Nestel et al. 2005)
Milk, fermented products, and cheese data are less conclusive(St-Onge et al. 2000, Nestel 2008, Ohlsson 2010)
Dairy Fat Efficacy Assessment StudyCollaborator Benoit Lamarche, Laval University
Contribution of genomic architecture to such observations has yet to be examined
Study visitDiet. recommendations
Diet. counselingAnthropometry
Blood sample3D FR+PA, and FFQ
24hr recallEndoPAT
DXACholesterol absorption
and biosynthesis
2 3 4Wk 0 61 5-1-2 7 8 9 10 11 12Sc
ree
nin
g
Run-in
CONTROL
DAIRY
DAIRY
CONTROL
Washout
Dairy randomized cross-over study design
Clinical assessmentn = 337
Eligiblen = 212
Excluded (n = 125)Did not meet inclusion criteria
Randomizedn = 137
Completed studyn = 124
Declined (n = 75)Chose not to participateor could not becontacted
Dropped out (n = 13)Never started, n = 7Protocol too demanding, n = 6
RCFFN, Winnipeg (n = 68)INAF, Quebec City (n = 69)
RCFFN, Winnipeg (n = 64)INAF, Quebec City (n = 60)
Genotypedn = 99
RCFFN, Winnipeg (n = 41)INAF, Quebec City (n = 58)
Could not be contacted to provideconsent for genotyping (n = 23)
Telephone screeningn = 623
Eligiblen = 346
Declined (n = 9)Time commitment
Excluded (n = 277)Did not meet inclusion criteria
Recruitment
chart
Abdullah et al. J Nutr. 2016
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
TC LDL-C
mm
ol/
L
Range: -1.10-1.15 mmol/L Range: -0.77-1.03 mmol/L
Changes from control of total (TC) and LDL
cholesterol (LDL-C) in response to dairy (n=99)
Abdullah et al. J Nutr. 2016
-0.80
-0.60
-0.40
-0.20
0.00
0.20
0.40
0.60
0.80
TC LDL-C
Δ, m
mo
l/L
GG + G + AGG + G + GGGG + TT + AGG + TT + GGC + G + AC + G + GGC + TT + AC + TT + GG
a
a
a
aa
a
a
aa
b
b
ab
ab
ab abab
Responses of serum total cholesterol and LDL-cholesterol concentrations to the 4-wk dairy diet compared with control in healthy adults stratified by ABCG5 rs6720173 + CYP7A1 rs3808607 + DHCR7 rs760241 genotypes (n = 7 rs6720173-GG + rs3808607-G + rs760241-A, n = 42 rs6720173-GG + rs3808607-G + rs760241-GG, n = 5 rs6720173-GG + rs3808607-TT + rs760241-A, n = 17 rs6720173-GG + rs3808607-TT + rs760241-GG, n = 6 rs6720173-C + rs3808607-G + rs760241-A, n = 11 rs6720173-C + rs3808607-G + rs760241-GG, n = 2 rs6720173-C + rs3808607-TT + rs760241-A, n = 9 rs6720173-C + rs3808607-TT + rs760241-GG). Values are least-square means ± SEMs. Effects of treatment by combined genotypes were assessed by using SAS ANCOVA, with gender as a fixed effect, and Tukey-Kramer adjustments. Labeled means without a common superscript letter are significantly different, P ≤ 0.05. ABCG5, ATP-binding cassette sub-family G member 5; CYP7A1, cholesterol 7 a-hydroxylase; DHCR7, 7-dehydrocholesterol reductase; LDL-C, LDL-cholesterol; TC, total cholesterol; Δ, change in cholesterol [post-diet (wk 4) dairy minus post-diet (wk 4) control values].
Response of Total and LDL-C to Dairy Intake as a Function of Three SNPs Working in Combination
(ABCG5 rs6720173, CYP7A1 rs3808607, DHCR7 rs760241)
• Responses of serum cholesterol to dairy fat product intake associate with genetic variants related to cholesterol metabolism
• In particular, common variants of ABCG5, CYP7A1, and DHCR7 genes may, individually and in combination, be involved in determining responses of serum cholesterol to the recommended level of dairy fat intake
Dairy Trial Conclusions
What other evidence exists in support
of genetic mechanisms explaining
inter-individual differences in
responsiveness to dietary bioactives?
n = 173 articles of ‘cholesterol-related gene-diet
interaction’ identified between 2003 and 2013
n = 69 observational and dietary intervention
articles included in the review
n = 49 articles (including 29 genes and 54
SNPs) showed significant gene-diet interactions
n = 104 articles
excluded; did not
investigate fasting
cholesterol response, did
not provide clear
associations, provided
limited research details,
review articles, animal
studies, and non-English
language
n = 20 articles showed no
significant cholesterol-
related gene-diet
interactions
2015
Reference Gene/SNP Design Diet Cholesterol effect
Viturro et al. 2006ABCG5
rs6720173
Cross-
sectional
14.3-34.1 g/d SFA
intake
↑ TC & LDL-C in
C>G vs. C/C male
carriers
De Castro-Oros
et al. 2010
CYP7A1
rs3808607Parallel
2 and 3.2 g/d PS
esters
↓ TC in G allele vs.
T/T carriers
Tucker
et al. 2010
APOE
E2, E3, E4Crossover
2/d whole grain
wheat or white
bread
↑ LDL-C in E3/E3
carriers with
whole grain vs.
white bread intake
Tipping point has been reached in understanding
that genetics play a role in determining the degree of
responsiveness of biomarkers to diet intervention…
Adapted from Abdullah et al. 2015
Impac
t on P
hen
oty
pe
Common
with smaller impact
Allele Frequency
Common
with large impact
Low
with moderate impact
Rare
with smaller impact
Rare
with large impact
<0.1% >5.0%
ABCG8 rs4148217-A
+5
+4
+3
+2+1
■
■
■
♦ABCG8 p.Pro231Thr♦
ABCG8 p.Arg263Gln
ABCG8 p.Gly574Arg♦
ABCA1 rs9282541-CABCA1 rs9282541-C
ABCG1 rs448102-A
ABCG1 rs448102-A
ABCG8 rs4148217-A■
ADIPOQ rs1501299-GADIPOQ rs1501299-T
APOA1 rs670-G
APOA1 rs1799837-G
APOA1 rs670-G APOA5 rs3135506-G
APOC3 rs5128-G
APOC3 rs202197102-T
APOC3 rs5128-C
APOE E2
APOE E2
APOE E2■
APOE E2 APOE E4■
■
CYP7A1 rs3808607-C ■
NPC1L1 rs2072183-G/rs10264715-A ■
■
■
■■
■■
■■
■
■
■
ABCG8 rs6544718-C
■
■
■
Abdullah et al. 2015
Allele frequency – phenotypic impact relationship
Impac
t on P
hen
oty
pe
Common
with smaller impact
Allele Frequency
Common
with large impact
Low
with moderate impact
Rare
with smaller impact
Rare
with large impact
<0.1% >5.0%
ABCG8 rs4148217-A
+5
+4
+3
+2+1
■
■
■
♦ABCG8 p.Pro231Thr♦
ABCG8 p.Arg263Gln
ABCG8 p.Gly574Arg♦
ABCA1 rs9282541-CABCA1 rs9282541-C
ABCG1 rs448102-A
ABCG1 rs448102-A
ABCG8 rs4148217-A■
ADIPOQ rs1501299-GADIPOQ rs1501299-T
APOA1 rs670-G
APOA1 rs1799837-G
APOA1 rs670-G APOA5 rs3135506-G
APOC3 rs5128-G
APOC3 rs202197102-T
APOC3 rs5128-C
APOE E2
APOE E2
APOE E2■
APOE E2 APOE E4■
■
CYP7A1 rs3808607-C ■
NPC1L1 rs2072183-G/rs10264715-A ■
■
■
■■
■■
■■
■
■
■
ABCG8 rs6544718-C
■
■
■
Abdullah et al. 2015
“The majority of current gene-diet interactions are
associated with common variants. Through epistatic
interactions of multiple common variants, effect sizes
could dramatically increase while the frequency for
each combination decreases”
Predicting biomarker response based on multiple SNPs
Majority of PopulationPossess Random SNP
Allocation
Mild Responsiveness
Minority of PopulationPossess Positive SNP Allocation
High Responsiveness
Minority of PopulationPossess Negative SNP Allocation
Non / Adverse Responsiveness
Gene-nutrient interactions can be seen in smaller nutritional intervention trials provided:
-Nutrient/ compliance is well controlled
-Response is accurately phenotyped
-Biological impact of SNP is large enough
A place exists given current knowledge for development of single and multiple SNP functional tests to distinguish between responders vs non-responders for dietary bioactives
Summary
AcknowledgementsMohammad AbdullahNancy AmesDavid BaerIsabelle DemontyDylan MacKayDavid PuTodd RideoutIwona RudkowskaSylvia SantosaPeter SujithElke TrautweinKrista VaradyYanan WangHailin Zhao
Canadian Institute for Health ResearchNatural Sciences and Engineering Research CouncilForbes Medi-Tech IncUnilever IncDanone IncWhitewave Inc