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LDL receptor gene mutations in italian children affected by familial hypercholesterolemia
XVII S.I.S.A. National Congress LDL RECEPTOR GENE M U T A T I O N S I N I T A L I A N AFFECTED BY F A M I L I A L HYPERCHOLESTEROLEMIA Gurdamagna Rabboni I
313 CHILDREN
O, B o n d o n e C, Bobbio A, Molini V, Giachino
P,
University of Turin Background: Familial Hypercholesterolemia (FH) is a genetic disorder of lipid metabolism caused by different mutations of the LDL-receptor (LDLP,) gene. Aim of this study is to correlate different mutations of LDLR gene in FH children to lipoprotein pattern and family history of cardiovascular disease (CVD). Methods: we recruited 18 FH children age 3-9 yrs; each subject was analyzed by screening LDLR gene and apolipoprotein (apo) E gene. All children underwent lipid profile evaluation: total cholesterol (TC), HDL cholesterol and triglycerides were evaluated with enzymatic method, apo B with immunoturbidimetric method. Family history was investigated with particular attention to CVD in first and second degree relatives. Results: we identified 12 different LDLP, gene mutations, 5 of which were firstly detected (1075delAGGATC on exon 8; E397X on exon 9; V510I, Y468C and W469R on exon 10). TC, LDL cholesterol (LDLC) and apo B levels range from 352 to 225, 286 to 126, 171 to 91 mg%. Apo E phenotype was E3/E3 in 10114 and E3/E4 in 3/14 children: average LDLC levels were 200 vs 242 mg%. One child presents E2/E3 phenotype with an LDLC value of 47% of the average LDLC levels reported in FH adults affected by the same LDLR gene mutation (135 vs 291 rag%). The family history of CVD was positive in 26/18 children and 9/18 reported precocious CVD among their relatives. Conclusions: we observed large variation of lipid levels among children affected by different LDLR gene mutations. Further studies will be necessary to define the relationship between LDLR mutations, apo E genotype, biochemical profile and cardiovascular risk.
SYNTHETIC HDL PROTECT ISCHEMIA/REPERFUSION INJURY
THE
HEART
AGAINST
M G o m a r a s c h i 1, G Rossoni 2, CR Sirtori 1, G Franceschini 1, L Calabresi 1 1Center Grossi PaoleLti, and 2Department of Pharmacological Sciences, University of Milano, Italy We have recently shown that plasma HDL can protect the heart against ischemia/reperfusion (I/P,) injury in an isolated heart model. To investigate the HDL component responsible for this effect, synthetic HDL (sHDL) were prepared with human apoA-I and synthetic PC and tested in the isolated heart. P,at hearts underwent a moderate ischemia for 20 min and then they were reperfused for 30 rain. Buffer-perfused hearts showed a clear-cut reduction of LV function with a consistent CK release. The perfusion of the hearts with sHDL (0.5-2.0 mg protein/ml buffer) during the last 10 rain before ischemia caused a dose-dependent protection against I/P, injury; sHDL at 2.0 mg/ml were associated with an almost complete recovery of LV pressure and a blunted CK release. sHDL were effective also when administered during the first 10 rain of reperfusion. Lipid-free apoA-I and EPC liposomes were totally ineffective, indicating that a lipoprotein structure is needed to exert the protective effect. Mechanisms responsible for the observed effect include the ability of sHDL to stimulate prostaglandin release, probably by COX-2 induction, and to bind and inactivate TNF-alpha, a potent cardiotexic cytokine. These findings indicate that sHDL are able to protect the heart against I/R injury, also when administered after ischemia, providing support to the therapeutic use of sHDL in a variety of clinical conditions characterized by ischemic injury.
PROTECTIVE ROLE OF S Y N T H E T I C HDL FROM I S C H E M I A R E P E R F U S I O N I N J U R Y : EX V I V O A N D I N V I V O MODELS
RELEVANCE OF HOMOCYSTEINE ON ATHEROSCLEROSIS I N H Y P E R L I P E M I C PAT I ENT S
M Marchesi 1, EA Booth 2, CR Sirtori ], CL Bisgaier 3, BR Lucchesi 2
Marchesi S, V a u d o G, Siepi D, Bageglia F, Paltriccie R, Lupattelli G, M e n n a r i n o E
1University of Milan, Italy; 2University of Michigan, USA; 3 Esperion Therapeutics, Inc, USA Myocardial injury is a potential consequence of coronary artery revascularization. We hypothesized that a synthetic HDL preparation (ETC-2:!.6) may protect the heart from reperfusion injury. The ex vivo model consisted of rabbit hearts perfused by the Langendorff method. Hearts were equilibrated with buffer (10rain), pretreated with ETC-216 (0.45mg/ml) or vehicle (10min), subjected to global ischemia (30min), and reperfused for 6groin. ETC-216 prevented left ventricular enddiastolic pressure (p<0.05) and coronary artery perfusion pressure (p<0.001) compared to vehicle. ETC-216 reduced the release of creatine kinase (p<0.00:[). Electron microscopy revealed ETC-216 prevented mitochondrial granulation and sarcomere contraction band formation. ETC-216 (100, 10, 3mg/kg) was assessed for its cardioprotective effects in an in vivo model of left anterior descending artery (LAD) occlusion and reperfusion. ETC-216 or vehicle was infused intravenously for 60min beginning 15rain before 30rain of LAD occlusion and extending 15min into the 4h reperfusion period. Infarct area (IA) as percent of the left ventricle (LV) was significantly smaller in animals treated with ETC-216 at 100 (p<0.05), 10 (p<0.0O01) or 3mg/kg (p<0.0:!.) compared to vehicle. In a second protocol, ETC-216 (10mg/kg) or vehicle was infused intravenously for 60rain beginning 5rain before the end of 30rain of LAD occlusion and extending 55rain into the 4h reperfusion period. ~ as percent of LV was significantly smaller in animals treated with ETC-216 (p<0.0005). Electron microscopy confirmed the ex vivo results. The findings suggest ETC-216 reduces reperfusion injury.
PRECLINICAL
Internal Medicine, Angiology and Arteriosclerosis - University of Perugia, Perugia, Italy Objective. To investigate the relevance of homocysteine on the preclinical atherosclerotic involvement in hypercholesterolemic patients without history of cardiovascular disease. Methods. In 192 hypercholesterolemics (divided on the basis of homocysteine levels HipH+ ~11 mmol/L and HIpH- < 11 retool/L) and in 98 healthy controls we assessed endothelial function as brachial flow-mediated and carotid and femoral INT. Results, HtpH-I- had values of mean IMT, at the internal carotid (1.13±0.16 vs 1.01~-0.13), at the common femoral (1.30±0.02 vs 1.094-0.02 mm) and superficial femoral (1.274"0.03 vs 1.004-0.02 ram) and max IMT at the common femoral (1.32=1:0.12 vs 1.114-0.08 mm) and superficial femoral (1.28:1:0.09 vs 1.084-0.05 ram) significantly higher respect to HIpH- patients; moreover they had also higher values of mean femoral (1.294-0.02 vs 1.074-0.09 mm) and max femoral (1.30:1:0.05 vs 1.094-0.09 ram) than HIpH- patients. Finally HIpH+ patients had significantly lower values of FMV at brachial level respect to HIpH- patients (1.86=1=1.83 vs 3.414-2.48 %). Multivariate regression analysis showed that LDL cholesterol and homocysteine were predictors of IC mean, F mean and F max IMT (p<0.01). Moreover LDL cholesterol and homocysteine predicted brachial FMV (p<0.05). Conclusions. Homocysteine levels were a relevant cofactor in preclinical atherosclerosis of hypercholesterolemic patients.
313 CHILDREN
O, B o n d o n e C, Bobbio A, Molini V, Giachino
P,
University of Turin Background: Familial Hypercholesterolemia (FH) is a genetic disorder of lipid metabolism caused by different mutations of the LDL-receptor (LDLP,) gene. Aim of this study is to correlate different mutations of LDLR gene in FH children to lipoprotein pattern and family history of cardiovascular disease (CVD). Methods: we recruited 18 FH children age 3-9 yrs; each subject was analyzed by screening LDLR gene and apolipoprotein (apo) E gene. All children underwent lipid profile evaluation: total cholesterol (TC), HDL cholesterol and triglycerides were evaluated with enzymatic method, apo B with immunoturbidimetric method. Family history was investigated with particular attention to CVD in first and second degree relatives. Results: we identified 12 different LDLP, gene mutations, 5 of which were firstly detected (1075delAGGATC on exon 8; E397X on exon 9; V510I, Y468C and W469R on exon 10). TC, LDL cholesterol (LDLC) and apo B levels range from 352 to 225, 286 to 126, 171 to 91 mg%. Apo E phenotype was E3/E3 in 10114 and E3/E4 in 3/14 children: average LDLC levels were 200 vs 242 mg%. One child presents E2/E3 phenotype with an LDLC value of 47% of the average LDLC levels reported in FH adults affected by the same LDLR gene mutation (135 vs 291 rag%). The family history of CVD was positive in 26/18 children and 9/18 reported precocious CVD among their relatives. Conclusions: we observed large variation of lipid levels among children affected by different LDLR gene mutations. Further studies will be necessary to define the relationship between LDLR mutations, apo E genotype, biochemical profile and cardiovascular risk.
SYNTHETIC HDL PROTECT ISCHEMIA/REPERFUSION INJURY
THE
HEART
AGAINST
M G o m a r a s c h i 1, G Rossoni 2, CR Sirtori 1, G Franceschini 1, L Calabresi 1 1Center Grossi PaoleLti, and 2Department of Pharmacological Sciences, University of Milano, Italy We have recently shown that plasma HDL can protect the heart against ischemia/reperfusion (I/P,) injury in an isolated heart model. To investigate the HDL component responsible for this effect, synthetic HDL (sHDL) were prepared with human apoA-I and synthetic PC and tested in the isolated heart. P,at hearts underwent a moderate ischemia for 20 min and then they were reperfused for 30 rain. Buffer-perfused hearts showed a clear-cut reduction of LV function with a consistent CK release. The perfusion of the hearts with sHDL (0.5-2.0 mg protein/ml buffer) during the last 10 rain before ischemia caused a dose-dependent protection against I/P, injury; sHDL at 2.0 mg/ml were associated with an almost complete recovery of LV pressure and a blunted CK release. sHDL were effective also when administered during the first 10 rain of reperfusion. Lipid-free apoA-I and EPC liposomes were totally ineffective, indicating that a lipoprotein structure is needed to exert the protective effect. Mechanisms responsible for the observed effect include the ability of sHDL to stimulate prostaglandin release, probably by COX-2 induction, and to bind and inactivate TNF-alpha, a potent cardiotexic cytokine. These findings indicate that sHDL are able to protect the heart against I/R injury, also when administered after ischemia, providing support to the therapeutic use of sHDL in a variety of clinical conditions characterized by ischemic injury.
PROTECTIVE ROLE OF S Y N T H E T I C HDL FROM I S C H E M I A R E P E R F U S I O N I N J U R Y : EX V I V O A N D I N V I V O MODELS
RELEVANCE OF HOMOCYSTEINE ON ATHEROSCLEROSIS I N H Y P E R L I P E M I C PAT I ENT S
M Marchesi 1, EA Booth 2, CR Sirtori ], CL Bisgaier 3, BR Lucchesi 2
Marchesi S, V a u d o G, Siepi D, Bageglia F, Paltriccie R, Lupattelli G, M e n n a r i n o E
1University of Milan, Italy; 2University of Michigan, USA; 3 Esperion Therapeutics, Inc, USA Myocardial injury is a potential consequence of coronary artery revascularization. We hypothesized that a synthetic HDL preparation (ETC-2:!.6) may protect the heart from reperfusion injury. The ex vivo model consisted of rabbit hearts perfused by the Langendorff method. Hearts were equilibrated with buffer (10rain), pretreated with ETC-216 (0.45mg/ml) or vehicle (10min), subjected to global ischemia (30min), and reperfused for 6groin. ETC-216 prevented left ventricular enddiastolic pressure (p<0.05) and coronary artery perfusion pressure (p<0.001) compared to vehicle. ETC-216 reduced the release of creatine kinase (p<0.00:[). Electron microscopy revealed ETC-216 prevented mitochondrial granulation and sarcomere contraction band formation. ETC-216 (100, 10, 3mg/kg) was assessed for its cardioprotective effects in an in vivo model of left anterior descending artery (LAD) occlusion and reperfusion. ETC-216 or vehicle was infused intravenously for 60min beginning 15rain before 30rain of LAD occlusion and extending 15min into the 4h reperfusion period. Infarct area (IA) as percent of the left ventricle (LV) was significantly smaller in animals treated with ETC-216 at 100 (p<0.05), 10 (p<0.0O01) or 3mg/kg (p<0.0:!.) compared to vehicle. In a second protocol, ETC-216 (10mg/kg) or vehicle was infused intravenously for 60rain beginning 5rain before the end of 30rain of LAD occlusion and extending 55rain into the 4h reperfusion period. ~ as percent of LV was significantly smaller in animals treated with ETC-216 (p<0.0005). Electron microscopy confirmed the ex vivo results. The findings suggest ETC-216 reduces reperfusion injury.
PRECLINICAL
Internal Medicine, Angiology and Arteriosclerosis - University of Perugia, Perugia, Italy Objective. To investigate the relevance of homocysteine on the preclinical atherosclerotic involvement in hypercholesterolemic patients without history of cardiovascular disease. Methods. In 192 hypercholesterolemics (divided on the basis of homocysteine levels HipH+ ~11 mmol/L and HIpH- < 11 retool/L) and in 98 healthy controls we assessed endothelial function as brachial flow-mediated and carotid and femoral INT. Results, HtpH-I- had values of mean IMT, at the internal carotid (1.13±0.16 vs 1.01~-0.13), at the common femoral (1.30±0.02 vs 1.094-0.02 mm) and superficial femoral (1.274"0.03 vs 1.004-0.02 ram) and max IMT at the common femoral (1.32=1:0.12 vs 1.114-0.08 mm) and superficial femoral (1.28:1:0.09 vs 1.084-0.05 ram) significantly higher respect to HIpH- patients; moreover they had also higher values of mean femoral (1.294-0.02 vs 1.074-0.09 mm) and max femoral (1.30:1:0.05 vs 1.094-0.09 ram) than HIpH- patients. Finally HIpH+ patients had significantly lower values of FMV at brachial level respect to HIpH- patients (1.86=1=1.83 vs 3.414-2.48 %). Multivariate regression analysis showed that LDL cholesterol and homocysteine were predictors of IC mean, F mean and F max IMT (p<0.01). Moreover LDL cholesterol and homocysteine predicted brachial FMV (p<0.05). Conclusions. Homocysteine levels were a relevant cofactor in preclinical atherosclerosis of hypercholesterolemic patients.