The risk of coronary heart disease (CHD) in systemic lupus erythematosus (SLE) women is up to 50 times higher than in the general population. The conventional risk factors are insufficient to explain premature CHD in SLE patients. Compared to about 1-5 percent prevalence of antiphospholipid antibodies (APA) in the general U.S. white population, about 50 percent of the SLE patients are positive for APA. ApoH is a principal autoantigen for the production of APA in patients with autoimmune diseases. ApoH inhibits the in vitro uptake of oxidized low-density lipoprotein (oxLDL) by macrophages, but in the presence of APA it promotes the ihflux of oxLDL into macrophages. As the accumulation of oxLDL in macrophages is believed to initiate the atherosclerotic process, these findings suggest that apoH-mediated immune response in patients with autoimmune diseases, like SLE, may lead to atherosclerosis. In this renewal we propose to examine the joint roles of APA, antibodies to oxLDL (anti-oxLDL) and APOH genetic variation (known and discovered as part of this proposal) in relation to the occurrence of CHD in SUE and non-SLE patients. Our hypothesis is that individuals positive for APA and/or anti-oxLDL are prone to premature CHD and this susceptibility is modified by common genetic variation in the APOH gene. The objectives of the study will be achieved by fulfilling the five aims.
Aim 1) identify and characterize naturally occurring common mutations in all exons, introns and the 3' region of the APOH gene by polymerase chain reaction (PCR), denaturing HPLC analysis and DNA sequencing in SLE and non-SLE CHD patients, and African blacks positive for APA.
Aim 2) determine the prevalence and correlation between APA (anti-apoH, anticardiolipin, lupus anticoagulant) and anti-oxLDL in plasma samples from SLE patients and controls.
Aim 3) determine the relationship between APOH genetic variation (data generated in Aim 1) and the occurrence of APA and anti-oxLDL (data generated in Aim 2).
Aim 4) examine the relationship between APOH genetic variation (data generated in Aim 1) and the occurrence of subclinical cardiovascular events in SLE patients and with coronary atherosclerosis in non-SLE patients.
Aim 5) perform in vitro mutagenesis and expression studies to express different apoH allelic-isoforms to evaluate isoform-specific inhibition of LDL oxidation.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL054900-07
Application #
6621198
Study Section
Special Emphasis Panel (ZRG1-CCVS (01))
Program Officer
Rabadan-Diehl, Cristina
Project Start
1997-01-01
Project End
2007-05-31
Budget Start
2003-06-01
Budget End
2004-05-31
Support Year
7
Fiscal Year
2003
Total Cost
$358,159
Indirect Cost
Name
University of Pittsburgh
Department
Genetics
Type
Schools of Public Health
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
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Chen, Qi; Reis, Steven E; Kammerer, Candace et al. (2011) Association of anti-oxidized LDL and candidate genes with severity of coronary stenosis in the Women's Ischemia Syndrome Evaluation study. J Lipid Res 52:801-7
Taylor, Kimberly E; Chung, Sharon A; Graham, Robert R et al. (2011) Risk alleles for systemic lupus erythematosus in a large case-control collection and associations with clinical subphenotypes. PLoS Genet 7:e1001311
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Suresh, Sangita; Demirci, F Yesim K; Jacobs, Erin et al. (2009) Apolipoprotein H promoter polymorphisms in relation to lupus and lupus-related phenotypes. J Rheumatol 36:315-22
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Hom, Geoffrey; Graham, Robert R; Modrek, Barmak et al. (2008) Association of systemic lupus erythematosus with C8orf13-BLK and ITGAM-ITGAX. N Engl J Med 358:900-9
Mehdi, Haider; Naqvi, Asma; Kamboh, M Ilyas (2008) Recombinant hepatitis B surface antigen and anionic phospholipids share a binding region in the fifth domain of beta2-glycoprotein I (apolipoprotein H). Biochim Biophys Acta 1782:163-8
Shih, P Betty; Manzi, Susan; Shaw, Penny et al. (2008) Genetic variation in C-reactive protein (CRP) gene may be associated with risk of systemic lupus erythematosus and CRP concentrations. J Rheumatol 35:2171-8
Musone, Stacy L; Taylor, Kimberly E; Lu, Timothy T et al. (2008) Multiple polymorphisms in the TNFAIP3 region are independently associated with systemic lupus erythematosus. Nat Genet 40:1062-4

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