Investigation and Functional Characterization of Rare Genetic Variants in the Adipose Triglyceride Lipase in a Large Healthy Working Population

English version České info

Recent studies demonstrated a strong influence of rare genetic variants on several lipid-related traits. However, their impact on free fatty acid (FFA) plasma concentrations, as well as the role of rare variants in a general population, has not yet been thoroughly addressed. The adipose triglyceride lipase (ATGL) is encoded by the PNPLA2 gene and catalyzes the rate-limiting step of lipolysis. It represents a prominent candidate gene affecting FFA concentrations. We therefore screened the full genomic region of ATGL for mutations in 1,473 randomly selected individuals from the SAPHIR (Salzburg Atherosclerosis Prevention program in subjects at High Individual Risk) Study using a combined Ecotilling and sequencing approach and functionally investigated all detected protein variants by in-vitro studies. We observed 55 novel mostly rare genetic variants in this general population sample. Biochemical evaluation of all non-synonymous variants demonstrated the presence of several mutated but mostly still functional ATGL alleles with largely varying residual lipolytic activity. About one-quarter (3 out of 13) of the investigated variants presented a marked decrease or total loss of catalytic function. Genetic association studies using both continuous and dichotomous approaches showed a shift towards lower plasma FFA concentrations for rare variant carriers and an accumulation of variants in the lower 10%-quantile of the FFA distribution. However, the generally rather small effects suggest either only a secondary role of rare ATGL variants on the FFA levels in the SAPHIR population or a recessive action of ATGL variants. In contrast to these rather small effects, we describe here also the first patient with “neutral lipid storage disease with myopathy” (NLSDM) with a point mutation in the catalytic dyad, but otherwise intact protein.

Vyšlo v časopise: Investigation and Functional Characterization of Rare Genetic Variants in the Adipose Triglyceride Lipase in a Large Healthy Working Population. PLoS Genet 6(12): e32767. doi:10.1371/journal.pgen.1001239
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.pgen.1001239

Souhrn

Zdroje

1. ManolioTA

CollinsFS

CoxNJ

GoldsteinDB

HindorffLA

2009 Finding the missing heritability of complex diseases. Nature 461 747 753

2. ReichDE

LanderES

2001 On the allelic spectrum of human disease. Trends Genet 17 502 510

3. PritchardJK

2001 Are rare variants responsible for susceptibility to complex diseases? Am J Hum Genet 69 124 137

4. BodmerW

BonillaC

2008 Common and rare variants in multifactorial susceptibility to common diseases. Nat Genet 40 695 701

5. KronenbergF

2008 Genome-wide association studies in aging-related processes such as diabetes mellitus, atherosclerosis and cancer. Exp Gerontol 43 39 43

6. FrazerKA

MurraySS

SchorkNJ

TopolEJ

2009 Human genetic variation and its contribution to complex traits. Nat Rev Genet 10 241 251

7. MaherB

2008 Personal genomes: The case of the missing heritability. Nature 456 18 21

8. GoldsteinDB

2009 Common genetic variation and human traits. N Engl J Med 360 1696 1698

9. SchorkNJ

MurraySS

FrazerKA

TopolEJ

2009 Common vs. rare allele hypotheses for complex diseases. Curr Opin Genet Dev 19 212 219

10. CohenJC

KissRS

PertsemlidisA

MarcelYL

McPhersonR

2004 Multiple rare alleles contribute to low plasma levels of HDL cholesterol. Science 305 869 872

11. CohenJC

PertsemlidisA

FahmiS

EsmailS

VegaGL

2006 Multiple rare variants in NPC1L1 associated with reduced sterol absorption and plasma low-density lipoprotein levels. Proc Natl Acad Sci U S A 103 1810 1815

12. KotowskiIK

PertsemlidisA

LukeA

CooperRS

VegaGL

2006 A spectrum of PCSK9 alleles contributes to plasma levels of low-density lipoprotein cholesterol. Am J Hum Genet 78 410 422

13. RomeoS

PennacchioLA

FuY

BoerwinkleE

Tybjaerg-HansenA

2007 Population-based resequencing of ANGPTL4 uncovers variations that reduce triglycerides and increase HDL. Nat Genet 39 513 516

14. AhituvN

KavaslarN

SchackwitzW

UstaszewskaA

MartinJ

2007 Medical sequencing at the extremes of human body mass. Am J Hum Genet 80 779 791

15. JiW

FooJN

O'RoakBJ

ZhaoH

LarsonMG

2008 Rare independent mutations in renal salt handling genes contribute to blood pressure variation. Nat Genet 40 592 599

16. NejentsevS

WalkerN

RichesD

EgholmM

ToddJA

2009 Rare variants of IFIH1, a gene implicated in antiviral responses, protect against type 1 diabetes. Science 324 387 389

17. AzzopardiD

DallossoAR

EliasonK

HendricksonBC

JonesN

2008 Multiple rare nonsynonymous variants in the adenomatous polyposis coli gene predispose to colorectal adenomas. Cancer Res 68 358 363

18. FearnheadNS

WinneyB

BodmerWF

2005 Rare variant hypothesis for multifactorial inheritance: susceptibility to colorectal adenomas as a model. Cell Cycle 4 521 525

19. FearnheadNS

WildingJL

WinneyB

TonksS

BartlettS

2004 Multiple rare variants in different genes account for multifactorial inherited susceptibility to colorectal adenomas. Proc Natl Acad Sci U S A 101 15992 15997

20. RomeoS

YinW

KozlitinaJ

PennacchioLA

BoerwinkleE

2009 Rare loss-of-function mutations in ANGPTL family members contribute to plasma triglyceride levels in humans. J Clin Invest 119 70 79

21. ZhaoZ

Tuakli-WosornuY

LagaceTA

KinchL

GrishinNV

2006 Molecular characterization of loss-of-function mutations in PCSK9 and identification of a compound heterozygote. Am J Hum Genet 79 514 523

22. FahmiS

YangC

EsmailS

HobbsHH

CohenJC

2008 Functional characterization of genetic variants in NPC1L1 supports the sequencing extremes strategy to identify complex trait genes. Hum Mol Genet 17 2101 2107

23. Carvajal-CarmonaLG

2010 Challenges in the identification and use of rare disease-associated predisposition variants. Curr Opin Genet Dev 20 277 281

24. AhnSM

KimTH

LeeS

KimD

GhangH

2009 The first Korean genome sequence and analysis: full genome sequencing for a socio-ethnic group. Genome Res 19 1622 1629

25. BentleyDR

BalasubramanianS

SwerdlowHP

SmithGP

MiltonJ

2008 Accurate whole human genome sequencing using reversible terminator chemistry. Nature 456 53 59

26. KimJI

JuYS

ParkH

KimS

LeeS

2009 A highly annotated whole-genome sequence of a Korean individual. Nature 460 1011 1015

27. LevyS

SuttonG

NgPC

FeukL

HalpernAL

2007 The diploid genome sequence of an individual human. PLoS Biol 5 e254 doi:10.1371/journal.pbio.0050254

28. WangJ

WangW

LiR

LiY

TianG

2008 The diploid genome sequence of an Asian individual. Nature 456 60 65

29. WheelerDA

SrinivasanM

EgholmM

ShenY

ChenL

2008 The complete genome of an individual by massively parallel DNA sequencing. Nature 452 872 876

30. ZimmermannR

StraussJG

HaemmerleG

SchoiswohlG

Birner-GruenbergerR

2004 Fat mobilization in adipose tissue is promoted by adipose triglyceride lipase. Science 306 1383 1386

31. JenkinsCM

MancusoDJ

YanW

SimsHF

GibsonB

2004 Identification, cloning, expression, and purification of three novel human calcium-independent phospholipase A2 family members possessing triacylglycerol lipase and acylglycerol transacylase activities. J Biol Chem 279 48968 48975

32. VillenaJA

RoyS

Sarkadi-NagyE

KimKH

SulHS

2004 Desnutrin, an adipocyte gene encoding a novel patatin domain-containing protein, is induced by fasting and glucocorticoids: ectopic expression of desnutrin increases triglyceride hydrolysis. J Biol Chem 279 47066 47075

33. ZechnerR

KienesbergerP

HaemmerleG

ZimmermannR

LassA

2009 Adipose triglyceride lipase and the lipolytic catabolism of cellular fat stores. J Lipid Res 50 3 21

34. SchweigerM

SchoiswohlG

LassA

RadnerFP

HaemmerleG

2008 The C-terminal region of human adipose triglyceride lipase affects enzyme activity and lipid droplet binding. J Biol Chem 283 17211 17220

35. DuncanRE

WangY

AhmadianM

LuJ

Sarkadi-NagyE

2009 Characterization of desnutrin functional domains:Critical residues for triacylglycerol hydrolysis in cultured cells. J Lipid Res 51 309 317

36. LassA

ZimmermannR

HaemmerleG

RiedererM

SchoiswohlG

2006 Adipose triglyceride lipase-mediated lipolysis of cellular fat stores is activated by CGI-58 and defective in Chanarin-Dorfman Syndrome. Cell Metab 3 309 319

37. YangX

LuX

LombesM

RhaGB

ChiYI

2010 The G(0)/G(1) Switch Gene 2 Regulates Adipose Lipolysis through Association with Adipose Triglyceride Lipase. Cell Metab 11 194 205

38. KershawEE

HammJK

VerhagenLA

PeroniO

KaticM

2006 Adipose triglyceride lipase: function, regulation by insulin, and comparison with adiponutrin. Diabetes 55 148 157

39. KershawEE

SchuppM

GuanHP

GardnerNP

LazarMA

2007 PPARgamma regulates adipose triglyceride lipase in adipocytes in vitro and in vivo. Am J Physiol Endocrinol Metab 293 E1736 E1745

40. FischerJ

LefevreC

MoravaE

MussiniJM

LaforetP

2007 The gene encoding adipose triglyceride lipase (PNPLA2) is mutated in neutral lipid storage disease with myopathy. Nat Genet 39 28 30

41. SchweigerM

LassA

ZimmermannR

EichmannTO

ZechnerR

2009 Neutral lipid storage disease: genetic disorders caused by mutations in adipose triglyceride lipase/PNPLA2 or CGI-58/ABHD5. Am J Physiol Endocrinol Metab 297 E289 E296

42. SchoenbornV

HeidIM

VollmertC

LingenhelA

AdamsTD

2006 The ATGL gene is associated with free fatty acids, triglycerides, and type 2 diabetes. Diabetes 55 1270 1275

43. JohansenCT

GallingerZR

WangJ

BanMR

YoungTK

2010 Rare ATGL haplotypes are associated with increased plasma triglyceride concentrations in the Greenland Inuit. Int J Circumpolar Health 69 3 12

44. LiQ

ZhangH

YuK

2010 Approaches for Evaluating Rare Polymorphisms in Genetic Association Studies. Hum Hered 69 219 228

45. KobayashiK

InoguchiT

MaedaY

NakashimaN

KuwanoA

2008 The Lack of the C-terminal Domain of Adipose Triglyceride Lipase Causes Neutral Lipid Storage Disease through Impaired Interactions with Lipid Droplets. J Clin Endocrinol Metab 93 2877 2884

46. AkmanHO

DavidzonG

TanjiK

MacdermottEJ

LarsenL

2010 Neutral lipid storage disease with subclinical myopathy due to a retrotransposal insertion in the PNPLA2 gene. Neuromuscul Disord 20 397 402

47. AkiyamaM

SakaiK

OgawaM

McMillanJR

SawamuraD

2007 Novel duplication mutation in the patatin domain of adipose triglyceride lipase (PNPLA2) in neutral lipid storage disease with severe myopathy. Muscle Nerve 36 856 859

48. OhkumaA

NonakaI

MalicdanMC

NoguchiS

OhjiS

2008 Distal lipid storage myopathy due to PNPLA2 mutation. Neuromuscul Disord 18 671 674

49. HuijsmanE

van de ParC

EconomouC

van der PoelC

LynchGS

2009 Adipose triacylglycerol lipase deletion alters whole body energy metabolism and impairs exercise performance in mice. Am J Physiol Endocrinol Metab 297 E505 E513

50. SchoiswohlG

SchweigerM

SchreiberR

GorkiewiczG

Preiss-LandlK

2010 Adipose triglyceride lipase plays a key role in the supply of the working muscle with fatty acids. J Lipid Res 51 490 499

51. YinW

RomeoS

ChangS

GrishinNV

HobbsHH

2009 Genetic Variation in ANGPTL4 Provides Insights into Protein Processing and Function. J Biol Chem 284 13213 13222

52. EpsteinDJ

2009 Cis-regulatory mutations in human disease. Brief Funct Genomic Proteomic 8 310 316

53. HeidIM

WagnerSA

GohlkeH

IglsederB

MuellerJC

2006 Genetic architecture of the APM1 gene and its influence on adiponectin plasma levels and parameters of the metabolic syndrome in 1,727 healthy Caucasians. Diabetes 55 375 384

54. TillBJ

ZerrT

BowersE

GreeneEA

ComaiL

2006 High-throughput discovery of rare human nucleotide polymorphisms by Ecotilling. Nucleic Acids Res 34: e99; Erratum in: Nucleic Acids Res 2006; 34 5352

55. CoassinS

BrandstätterA

KronenbergF

2008 An optimized procedure for the design and evaluation of Ecotilling assays. BMC Genomics 9 510 520

56. HolmC

OlivecronaG

OttossonM

2001 Assays of lipolytic enzymes. Methods Mol Biol 155 97 119

57. AdzhubeiIA

SchmidtS

PeshkinL

RamenskyVE

GerasimovaA

2010 A method and server for predicting damaging missense mutations. Nat Methods 7 248 249

58. NgPC

HenikoffS

2003 SIFT: Predicting amino acid changes that affect protein function. Nucleic Acids Res 31 3812 3814

59. Ferrer-CostaC

GelpiJL

ZamakolaL

ParragaI

de la CruzX

2005 PMUT: a web-based tool for the annotation of pathological mutations on proteins. Bioinformatics 21 3176 3178

60. CoassinS

BrandstätterA

KronenbergF

2010 Lost in the space of bioinformatic tools: A constantly updated survival guide for genetic epidemiology. The GenEpi Toolbox. Atherosclerosis 209 321 335

61. LarkinMA

BlackshieldsG

BrownNP

ChennaR

McGettiganPA

2007 Clustal W and Clustal X version 2.0. Bioinformatics 23 2947 2948