Abstract 1096: Predictors Of Carotid Intimal-medial Thickness In Subjects With Hyperalphalipoproteinemia

HDL cholesterol (HDL-C) is inversely associated with risk for CVD in the general population. However, the metabolic pathways leading to high HDL (hyperalphalipoproteinemia) are complex, and some patients with high HDL-C are not protected against atherosclerotic disease. The purpose of this study was to determine the associations between CVD risk factors, especially HDL subpopulations, and subclinical vascular disease in patients with high HDL-C. Community-dwelling adult subjects with and without CAD between the ages of 18 – 80 years with HDL-C levels above 60 mg/dl were recruited for this study (n=46, 34 women and 12 men, mean age 58.7 ± 9.7 years). After an overnight fast, blood was obtained for measurement of lipids, inflammatory markers and lipoproteins by NMR spectroscopy (Liposcience, NC) and 2D-gel analysis. Far wall common carotid artery intimal-medial thickness (IMT) was measured using carotid ultrasonography. None of the subjects were taking statins. The lipid levels (mean ± SD) were total cholesterol 225.6 ± 37.9 mg/dl, triglycerides 77.9 ± 29.4 mg/dl, HDL 90.4 ± 22.5 mg/dl and LDL 119.6 ± 33.4 mg/dl. Carotid IMT values were normally distributed, with a range of 0.46 –1.1 mm. Unadjusted pairwise-correlations showed that carotid IMT was significantly associated with LDL particle number ( p< 0.03), HDL subpopulations by 2D-gel analysis [α-3: p< 0.005; α-4: p< 0.04; and preα-1: p< 0.03], C-reactive protein ( p< 0.03), sVCAM-1 ( p< 0.02), age ( p< 0.0008), systolic blood pressure ( p< 0.02), heart rate ( p< 0.02) and corneal arcus ( p< 0.04). Carotid IMT was not associated with any traditional lipid level, gender or history of CAD. In a multiple regression model, age ( p =0.0007), α-3 ( p< 0.008) and CRP ( p< 0.03) were significant independent predictors of carotid IMT in this population. Thus, in subjects with hyperalphalipoproteinemia, increased small, dense HDL (α-3) and CRP levels were associated with increasing carotid IMT, suggesting heterogeneity in the role of HDL particles on subclinical atherosclerosis.

A Proteomic Approach to Discovery of Candidate Proteins Involved in the Transformation of Follicular Lymphoma.

Background: Follicular lymphoma (FL) undergoes transformation to a high grade diffuse large B-cell lymphoma (tr-DLBCL) in about 50% of patients. During transformation, a more virulent subclone of tumor cells emerges, leading to a rapidly progressive clinical course and resistance to therapy. The identification of proteins involved in transformation is critical for understanding the mechanism of transformation and developing molecularly targeted therapy. In this study, we compared protein expression between grade 1- FL (G1-FL) and tr-DLBCL using 2D-gel electrophoresis and Western blot analysis. Design: Frozen tissue and frozen cells were obtained from the Department of Pathology, Oregon Health and Science University tumor bank. The protein expression profiles of 3 G1-FL and 3 tr-DLBCL were compared using 2D-gel electrophoresis. Protein identification was done using a MALDI mass spectrometer. Frozen cells of an additional 11 non-paired GI-FL and 11 non-paired tr-DLBCL, and 2 pairs of G1-FL and tr-DLBCL specimens were used for Western blot confirmation of the initial 2D-gel findings. Results: 2D-gel analysis and MALDI protein identification revealed 14 differentially expressed proteins between G1-FL and tr-DLBCL (figure 1), all of which are known to play important roles in cellular energy/metabolic pathways, signal transduction pathways, and protein and nuclear synthesis. The two most differentially expressed proteins on 2D-gel analysis were superoxide dismutase (MnSOD2) and growth factor receptor bound protein 2 (Grb2). Western blot analysis of MnSOD2 and Grb2 confirmed their relative over- or under-expression in frozen cells from multiple additional clinical lymphoma samples, including 2 paired- and 22 non-paired G1-FL and tr-DLBCL. Both 2D-gel analysis and Western Blot showed a significantly higher level of expression of MnSOD2 and a lower expression of Grb2 expression in tr-DLBCL (figure 2). Summary: Using proteomic profiling, confirmed by Western blot analysis of clinical G1-FL and tr-DLBCL samples, we have confirmed 2 proteins (MnSOD2 and Grb2) that are expressed at significantly different levels in G1-FL and DLBCL. MnSOD2 is capable of protecting cells from reactive oxygen species and regulating signal transduction pathways to influence cell growth and apoptosis. Inhibition of MnSOD2 has been shown in studies of several cancer cell lines to render cancer cells more susceptible to apoptosis. Grb2 is a member of a critical signaling pathway leading to Ras activation in hematopoietic cells. Both proteins may play a critical role in FL transformation. These proteins have the potential to be therapeutic drug targets, diagnostic and/or prognostic markers, or biomarkers for monitoring therapeutic response. Summary of Differentially Expressed Spots Summary of Differentially Expressed Spots Figure Figure