From Wikipedia, the free encyclopedia
Cholesteryl ester transfer protein (CETP), also
called plasma lipid transfer protein, is a plasma protein that facilitates the
transport of cholesteryl esters and triglycerides between
the lipoproteins. It
collects triglycerides from very-low-density (VLDL) or low-density lipoproteins (LDL)
and exchanges them for cholesteryl esters from high-density lipoproteins
(HDL), and vice versa. Most of the time, however, CETP does a
homoexchange, trading a triglyceride for a triglyceride or a
cholesteryl ester for a cholesteryl ester.
Genetics
The CETP gene is located on the sixteenth chromosome (16q21).
Role in
disease
Rare mutations leading to increased function of CETP have been
linked to accelerated atherosclerosis.[1]
In contrast, a polymorphism (I405V) of the CETP gene
leading to lower serum levels has also been linked to exceptional
longevity.[2]
However, this mutation also increases the prevalence of coronary
heart disease in patients with hypertriglyceridemia.[3] The
D442G mutation, which lowers CETP levels and increases HDL levels
also increases coronary heart disease.[1]
Elaidic acid, a
major component of trans
fat, increases CETP activity.[4]
Pharmacology
As HDL can alleviate
atherosclerosis and other cardiovascular diseases, and
certain disease states such as the metabolic syndrome feature low HDL,
pharmacological inhibition of CETP is being studied as a method of
improving HDL levels.[5] To be
specific, in a 2004 study, the small molecular agent torcetrapib was shown
to increase HDL levels, alone and with a statin, and lower LDL when co-administered with
a statin.[6] Studies
into cardiovascular endpoints, however, were largely disappointing.
While they confirmed the change in lipid levels, most reported an
increase in blood
pressure, no change in atherosclerosis,[7][8] and, in
a trial of a combination of torcetrapib and atorvastatin, an
increase in cardiovascular events and mortality.[9]
A compound related to torcetrapib, with the investigative name
JTT-705/R1658, is also being studied.[10] It
increases HDL levels by 30%, as compared to 60% by torcetrapib.[11]
Another CETP inhibitor under development is Merck's MK-0859 anacetrapib, which in
initial studies is not shown to increase blood pressure.[12]
References
- ^ a
b
Zhong S, Sharp DS, Grove JS, Bruce
C, Yano K, Curb JD, Tall AR (June 1996). "Increased coronary heart
disease in Japanese-American men with mutation in the cholesteryl
ester transfer protein gene despite increased HDL levels".
J Clin Invest 97 (12): 2917–23. doi:10.1172/JCI118751.
ISSN 0021-9738. PMID 8675707. PMC 507389. http://www.jci.org/cgi/content/full/97/12/2917.
- ^
Barzilai N, Atzmon G, Schechter C,
Schaefer EJ, Cupples AL, Lipton R, Cheng S, Shuldiner AR (October
2003). "Unique lipoprotein phenotype
and genotype associated with exceptional longevity".
JAMA 290 (15): 2030–40. doi:10.1001/jama.290.15.2030. ISSN 0098-7484. PMID 14559957. http://jama.ama-assn.org/cgi/content/full/290/15/2030.
- ^
Bruce C, Sharp DS, Tall AR (1 May
1998). "Relationship of HDL and
coronary heart disease to a common amino acid polymorphism in the
cholesteryl ester transfer protein in men with and without
hypertriglyceridemia". J Lipid Res 39
(5): 1071–8. ISSN 0022-2275. PMID 9610775. http://www.jlr.org/cgi/content/full/39/5/1071.
- ^ Abbey M, Nestel PJ (March 1994). "Plasma
cholesteryl ester transfer protein activity is increased when
trans-elaidic acid is substituted for cis-oleic acid in the diet".
Atherosclerosis 106 (1): 99–107. doi:10.1016/0021-9150(94)90086-8. ISSN 0021-9150. PMID 8018112.
- ^
Barter PJ, Brewer HB Jr, Chapman MJ,
Hennekens CH, Rader DJ, Tall AR (February 2003). "Cholesteryl ester transfer
protein: a novel target for raising HDL and inhibiting
atherosclerosis". Arterioscler Thromb Vasc Biol
23 (2): 160–7. doi:10.1161/01.ATV.0000054658.91146.64. ISSN 1079-5642. PMID 12588754. http://atvb.ahajournals.org/cgi/content/full/23/2/160.
- ^
Brousseau ME, Schaefer EJ, Wolfe ML,
Bloedon LT, Digenio AG, Clark RW, Mancuso JP, Rader DJ (April
2004). "Effects of an inhibitor of
cholesteryl ester transfer protein on HDL cholesterol". N
Engl J Med 350 (15): 1505–15. doi:10.1056/NEJMoa031766. ISSN 0028-4793. PMID 15071125. http://content.nejm.org/cgi/content/full/350/15/1505.
- ^
Nissen Se, Tardif JC; Investigators,
Illustrate (March 2007). "Effect of torcetrapib on the
progression of coronary atherosclerosis". N Engl J Med
356 (13): 1304–16. doi:10.1056/NEJMoa070635. ISSN 0028-4793. PMID 17387129. http://content.nejm.org/cgi/content/full/356/13/1304.
- ^
Kastelein Jj, van Leuven SI;
Investigators, Radiance 1. (April 2007). "Effect of torcetrapib on
carotid atherosclerosis in familial hypercholesterolemia"
(abstract). N Engl J Med 356 (16):
1620–30. doi:10.1056/NEJMoa071359. ISSN 0028-4793. PMID 17387131. http://content.nejm.org/cgi/content/abstract/356/16/1620.
- ^ U.S. Food and Drug Administration
(2006-12-03). "Pfizer Stops All Torcetrapib
Clinical Trials in Interest of Patient Safety". Press
release. http://www.fda.gov/bbs/topics/news/2006/new01514.html.
- ^
El Harchaoui K, van der Steeg WA,
Stroes ES, Kastelein JJ (August 2007). "The role of CETP inhibition
in dyslipidemia". Curr Atheroscler Rep 9
(2): 125–33. doi:10.1007/s11883-007-0008-5. ISSN 1523-3804. PMID 17877921.
- ^
de Grooth GJ, Kuivenhoven JA,
Stalenhoef AF, de Graaf J, Zwinderman AH, Posma JL, van Tol A,
Kastelein JJ (May 2002). "Efficacy and safety of a
novel cholesteryl ester transfer protein inhibitor, JTT-705, in
humans: a randomized phase II dose-response study".
Circulation 105 (18): 2159–65. doi:10.1161/01.CIR.0000015857.31889.7B. ISSN 0009-7322. PMID 11994249. http://circ.ahajournals.org/cgi/content/full/circulationaha;105/18/2159.
- ^
Reuters (2007-10-04). "Merck announces its
investigational CETP-Inhibitor, MK-0859, produced positive effects
on lipids with no observed blood pressure changes". Reuters,
Inc.. http://www.reuters.com/article/inPlayBriefing/idUSIN20071004163052MRK20071004. Retrieved
2007-11-04.
Further
reading
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PDB Gallery |
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2obd: Crystal Structure of Cholesteryl Ester
Transfer Protein
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External
links