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009 Elevated Serum PCSK9 in Normal Third Trimester Pregnancy, Pre-Eclampsia and Intrauterine Growth Restriction
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transaortic gradient (r2 adjusted⫽0.24; p⬍0.0001). In addition, the density of leukocytes within CAVD was independently related to the progression rate of aortic stenosis (r2 adjusted⫽0.10, p⫽0.04). CONCLUSION: Dense inflammatory infiltrates within CAVD are associated with an active remodelling process, the severity and the hemodynamic progression rate of CAVD.
008 MICRORNA EXPRESSION IN BLOOD DERIVED MONONUCLEAR CELLS DURING MATURATION FROM EARLY TO LATE OUTGROWTH ENDOTHELIAL PROGENITOR CELLS J Behbahani, DJ Stewart Ottawa, Ontario
Endothelial Progenitor Cells (EPCs) circulate in the peripheral blood mononuclear cell (PBMC) fraction and can be selected under culture conditions which include appropriate matrix components and endothelial growth factors. Early outgrowth EPCs appear after the first 3 to 5 days of selective culture, and these nonproliferative cells still express MNC markers (i.e. CD14 and CD45), but also express some endothelial cell (EC) markers including CD31 and VEGFR2. Late outgrowth EPCs appear after 2 weeks, and exhibit a strong EC phenotype, and this highly proliferative population has lost all leukocyte markers. MicroRNAs (miRNAs) are small noncoding RNAs that have emerged as important regulators of gene expression. OBJECTIVE: The aim of this study was to define the changes in miRNA expression profiles in MNC cultures during evolution from early to late outgrowth EPC. HYPOTHESIS: Changes in the expression of specific miRNAs contribute to the endothelial specification of cultured MNCs and the emergence of early or late outgrowth EPCs. METHODS AND RESULTS: Mononuclear cells (MNCs) were isolated from healthy participants (n⫽4) by leukaphesis and cultured for 1, 3, 5, 7 and 9 days under conditions promoting endothelial differentiation. Late outgrowth EPCs were derived from the same cultures and appeared after 14-21 days (n⫽3). MiRNA expression was assessed by (q)RT-PCR (Taqman), using a panel of 13 miRNAs previously identified in PBMCs, EPCs or mature ECs. MiRNA expression profiles were very similar in cells between 1 and 3 days (cultured MNCs); and 5, 7 and 9 days (early outgrowth EPCs), and therefore these were grouped for further analysis. MiR-92a was highly dominant in day 1-3 MNC cultures and remained relatively constant throughout the culture period. In early outgrowth EPCs (day 5-9), the expression of miR-146a increased 2.9⫾0.04 fold, (p⬍0.05). In contrast, late outgrowth EPCs exhibited marked increases in expression of miRs-126 , -222 and -221 compared to early EPCs (by 453-, 14- and 8.4-folds respectively; p⬍0.05). The ratio of miR-126 to miR-146 provided the strongest indicator of endothelial differentiation. CONCLUSION: These data demonstrate that MNCs exhibit specific patterns of miRNA expression tightly associated with the BACKGROUND:
Canadian Journal of Cardiology Volume 28 2012
progression from early to late outgrowth EPCs. MiRNAs may play a critical role in regulating the maturation of MNCs from early to late outgrowth EPCs, and enhancing miR-126 or suppressing miR-146 may facilitate their differentiation to an endothelial phenotype.
009 ELEVATED SERUM PCSK9 IN NORMAL THIRD TRIMESTER PREGNANCY, PRE-ECLAMPSIA AND INTRAUTERINE GROWTH RESTRICTION P Peticca, A Gruslin, M Cousins, E Adetola, J Mayne, T Ooi Ottawa, Ontario BACKGROUND: Pregnancy is associated with higher maternal serum concentrations of total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) in spite of hyperestrogenemia, which in the non-pregnant state is associated with lower TC and LDL-C levels. It is unknown whether proprotein convertase subtilisin kexin 9 (PCSK9) plays a role in the elevation of LDL-C during pregnancy. PCSK9 promotes the post-translational degradation of the LDL receptor on the cell surface, thereby inhibiting clearance of LDL-C in circulation. Our study assessed whether serum PCSK9 concentrations change in third trimester pregnancy when compared to non-pregnant healthy women. METHODS: Maternal serum was collected at the time of delivery from women with normal pregnancy, pre-eclampsia (PET) and intrauterine growth restriction (IUGR). Paired umbilical cord blood was also collected for analysis. Serum lipids and PCSK9 were measured in the collected samples. RESULTS: Compared to the non-pregnant state, serum PCSK9 was significantly higher in third trimester pregnancy (554⫾223 versus 342⫾177 ng/ml for normal pregnancy; 513⫾189 versus 342⫾177 ng/ml for PET; and 525⫾157 versus 342⫾177 ng/ml for IUGR) (p⬍0.0001). Umbilical cord blood levels of PCSK9 were much lower than maternal blood levels (538⫾184 versus 306⫾135 ng/ml; p⬍0.0001). CONCLUSION: Our study provides the first observation of a significant increase in circulating PCSK9 in pregnancy compared to the non-pregnant state. The same degree of PCSK9 elevation was seen in pregnancies complicated by PET and IUGR as in normal pregnancy. Our findings raise the possibility that PCSK9 may mediate the LDL-C elevation associated with pregnancy. HSFC
010 INFLUENCE OF DUAL ENERGY, ITERATIVE RECONSTRUCTION AND SPATIAL RESOLUTION ON ACCURATE DETERMINATION OF LUMEN STENOSIS DURING CT CORONARY ANGIOGRAPHY: A PHANTOM STUDY A Ursani, H Mehrez, NS Paul Toronto, Ontario
This study will determine the impact of Dual Energy (DE), Iterative Reconstruction (IR) and Spatial Reso-
BACKGROUND:
transaortic gradient (r2 adjusted⫽0.24; p⬍0.0001). In addition, the density of leukocytes within CAVD was independently related to the progression rate of aortic stenosis (r2 adjusted⫽0.10, p⫽0.04). CONCLUSION: Dense inflammatory infiltrates within CAVD are associated with an active remodelling process, the severity and the hemodynamic progression rate of CAVD.
008 MICRORNA EXPRESSION IN BLOOD DERIVED MONONUCLEAR CELLS DURING MATURATION FROM EARLY TO LATE OUTGROWTH ENDOTHELIAL PROGENITOR CELLS J Behbahani, DJ Stewart Ottawa, Ontario
Endothelial Progenitor Cells (EPCs) circulate in the peripheral blood mononuclear cell (PBMC) fraction and can be selected under culture conditions which include appropriate matrix components and endothelial growth factors. Early outgrowth EPCs appear after the first 3 to 5 days of selective culture, and these nonproliferative cells still express MNC markers (i.e. CD14 and CD45), but also express some endothelial cell (EC) markers including CD31 and VEGFR2. Late outgrowth EPCs appear after 2 weeks, and exhibit a strong EC phenotype, and this highly proliferative population has lost all leukocyte markers. MicroRNAs (miRNAs) are small noncoding RNAs that have emerged as important regulators of gene expression. OBJECTIVE: The aim of this study was to define the changes in miRNA expression profiles in MNC cultures during evolution from early to late outgrowth EPC. HYPOTHESIS: Changes in the expression of specific miRNAs contribute to the endothelial specification of cultured MNCs and the emergence of early or late outgrowth EPCs. METHODS AND RESULTS: Mononuclear cells (MNCs) were isolated from healthy participants (n⫽4) by leukaphesis and cultured for 1, 3, 5, 7 and 9 days under conditions promoting endothelial differentiation. Late outgrowth EPCs were derived from the same cultures and appeared after 14-21 days (n⫽3). MiRNA expression was assessed by (q)RT-PCR (Taqman), using a panel of 13 miRNAs previously identified in PBMCs, EPCs or mature ECs. MiRNA expression profiles were very similar in cells between 1 and 3 days (cultured MNCs); and 5, 7 and 9 days (early outgrowth EPCs), and therefore these were grouped for further analysis. MiR-92a was highly dominant in day 1-3 MNC cultures and remained relatively constant throughout the culture period. In early outgrowth EPCs (day 5-9), the expression of miR-146a increased 2.9⫾0.04 fold, (p⬍0.05). In contrast, late outgrowth EPCs exhibited marked increases in expression of miRs-126 , -222 and -221 compared to early EPCs (by 453-, 14- and 8.4-folds respectively; p⬍0.05). The ratio of miR-126 to miR-146 provided the strongest indicator of endothelial differentiation. CONCLUSION: These data demonstrate that MNCs exhibit specific patterns of miRNA expression tightly associated with the BACKGROUND:
Canadian Journal of Cardiology Volume 28 2012
progression from early to late outgrowth EPCs. MiRNAs may play a critical role in regulating the maturation of MNCs from early to late outgrowth EPCs, and enhancing miR-126 or suppressing miR-146 may facilitate their differentiation to an endothelial phenotype.
009 ELEVATED SERUM PCSK9 IN NORMAL THIRD TRIMESTER PREGNANCY, PRE-ECLAMPSIA AND INTRAUTERINE GROWTH RESTRICTION P Peticca, A Gruslin, M Cousins, E Adetola, J Mayne, T Ooi Ottawa, Ontario BACKGROUND: Pregnancy is associated with higher maternal serum concentrations of total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) in spite of hyperestrogenemia, which in the non-pregnant state is associated with lower TC and LDL-C levels. It is unknown whether proprotein convertase subtilisin kexin 9 (PCSK9) plays a role in the elevation of LDL-C during pregnancy. PCSK9 promotes the post-translational degradation of the LDL receptor on the cell surface, thereby inhibiting clearance of LDL-C in circulation. Our study assessed whether serum PCSK9 concentrations change in third trimester pregnancy when compared to non-pregnant healthy women. METHODS: Maternal serum was collected at the time of delivery from women with normal pregnancy, pre-eclampsia (PET) and intrauterine growth restriction (IUGR). Paired umbilical cord blood was also collected for analysis. Serum lipids and PCSK9 were measured in the collected samples. RESULTS: Compared to the non-pregnant state, serum PCSK9 was significantly higher in third trimester pregnancy (554⫾223 versus 342⫾177 ng/ml for normal pregnancy; 513⫾189 versus 342⫾177 ng/ml for PET; and 525⫾157 versus 342⫾177 ng/ml for IUGR) (p⬍0.0001). Umbilical cord blood levels of PCSK9 were much lower than maternal blood levels (538⫾184 versus 306⫾135 ng/ml; p⬍0.0001). CONCLUSION: Our study provides the first observation of a significant increase in circulating PCSK9 in pregnancy compared to the non-pregnant state. The same degree of PCSK9 elevation was seen in pregnancies complicated by PET and IUGR as in normal pregnancy. Our findings raise the possibility that PCSK9 may mediate the LDL-C elevation associated with pregnancy. HSFC
010 INFLUENCE OF DUAL ENERGY, ITERATIVE RECONSTRUCTION AND SPATIAL RESOLUTION ON ACCURATE DETERMINATION OF LUMEN STENOSIS DURING CT CORONARY ANGIOGRAPHY: A PHANTOM STUDY A Ursani, H Mehrez, NS Paul Toronto, Ontario
This study will determine the impact of Dual Energy (DE), Iterative Reconstruction (IR) and Spatial Reso-
BACKGROUND: