- Email: [email protected]
120 Adaptor protein ARH modulates the endocytosis of LDL-LDLR complexes in hepatocytes
$26
Nutrition, Metabolism & Cardiovascular Diseases, Volume 15 (2005) Supplement i
moderate weight loss program may have some effects on both cytokines. The relationship between plasma adiponectin and IL-10 levels was analyzed in 64 android [body mass index (BMI) >28 and waist-to-hip ratio (WHR) ~>0.86] and 20 gynoid [BMI > 28 and WHR < 0.86] obese healthy women. Android obese women (49±14 years) had a mean BMI of 37.1±5.3, similar to that of gynoid obese (49±11 years; BMI: 33.4±2.6). Twenty non-obese control women (46±11 years, BMI: 25.2±2.2) were also studied. In 12 android obese women measurements were repeated after a 12-week period of diet (1200 kcal/d). Median adiponectin (5.2 [3.3-7.8] vs. 12.1 [9.7 13.9] andvs. 15.0 [12.6 18.2] ~tg/mL, p<0.0001) and IL-10 (1.8 [1.2-3.3] vs. 3.5 [2.9-4.3] and vs. 4.1 [3.5-4.8] pg/mL, p < 0.0001) levels were lower in android vs. gynoid and vs. non-obese women. Among android obese women, low adiponectin levels were independent predictors (p < 0.0001) of decreased IL-10 levels, independently of BMI, WHR or insulin resistance. No change either in adiponectin or in IL-10 levels was observed after body weight reduction (8±4kg, p < 0.01). Android obesity is associated with a down-regulation of IL-10, which is closely related to low adiponectin levels. However, anti-inflammatory status of obesity might require prolonged periods of energy-restricted diets to revert to normal.
•
INSULIN RESISTANCE AS A DETERMINANT OF PLATELET ACTIVATION IN OBESE WOMEN
F. SaJntilli1 , S. Basili2, G. Pacini 3, M.T. Guagnano 1 , M.R. Manigrasso 1 , L. Pescara 1 , G. Ciabattoni 1 , C. Patrono 4, G. Davi 1 . 1Uenter of Evcellence on Aging, Unic,ersiO, of (;~ieti "G. D 'Anmmzio "," 2Metabolic Unit, Institute of Biomedical Engineering, National Research Uouncil, Padoc,a; atM Departments of 3Medical Therapy arm 4Pha~vtacologv. Unic,ersiO~ of Rome "La Sapienza ". Italy E-mail: [email protected] Background: Obesity is associated with persistent platelet activation in otherwise healthy women. We tested the hypothesis that insulin resistance per se contributes to increased platelet activation in this setting. Methods and Results: We performed a cross-sectional study in 40 obese and 20 non-obese women using urinary thromboxane (TX) metabolite excretion as a non-invasive index of platelet activation. An index of insulin sensitivity, SI, was calculated and plasma adiponectin, C-reactive protein (CRP) and CD40 ligand (CD40L) levels were measured as potential determinants of increased platelet activation. Obese women had significantly higher 11-dehydro-TXB2 excretion rate (p < 0.0001), CRP (p < 0.0001) and CD40L levels (p < 0.0001) and lower SI (p < 0.002) and adiponectin (p < 0.01) than controls. On multiple regression analysis waist-tohip ratio (p < 0.05) and SI (p < 0.04) predicted 11-dehydro-TXB2 excretion, independently of adiponectin, inflammatory and lipid patterns. To investigate the cause effect relationship of these associations, we examined the effects of a 12-week weight loss program on urinary 11-dehydro-TXB2 in 10 obese women with impaired SI and visceral obesity. Successful weight loss achieved in 5 subjects was associated with an increase in SI (+92%) and a decrease in CD40L ( 2 7 % ) , CRP ( 3 7 % ) and ll-dehydro-TXB2 ( 5 3 % ) , (p<0.05). Conclusions: insulin resistance is a major determinant of platelet activation in female obesity.
•
IMPACT OF TREATMENT WITH PROTEASE INHIBITORS ON AORTIC STIFFNESS IN ADULT PATIENTS WITH HUMAN IMMUNODEFICIENCY VIRUS INFECTION
G. Savarese, G. Schillaci, G.VL. De Socio, M. Pirro, M.R. Mannarino, E Baldelli, G. Stagni, E. Mannarino. Medicina Inte~Tza, Angiologia e Malattie da Arteriosclerosi, Unic,ers&'l di Perugia, Italy E-mail: [email protected] The role of antiretroviral therapy in acceleration of atherosclerosis in patients with human immunodeficiency virus (HIV) infection is controversial. We hypothesized that aortic stiffness, an early marker of arteriosclerosis, may be increased in HIV patients treated with protease inhibitors. In 32 HIV-infected patients treated with protease inhibitors aJnd 32 age-, sex- aJnd blood pressure-matched HIV-uninfected control subjects, we obtained aortic pulse wave velocity and central aortic pressure waveform, from which aortic augmentation was calculated. HIV patients had a higher aortic pulse wave velocity (7.6±1.1 vs 6.8±l.2m/s, p 0.015) and aortic augmentation (6.8±5 vs 4.6±4mmHg, p 0.037) thaJn control subjects. Age and HIV infection (both p < 0.05) independently predicted aortic pulse wave velocity when a consistent number of cardiovascular risk factors was simultaneously controlled for. The cumulative duration of treatment was a predictor of aortic pulse wave velocity, each 5 years of treatment duration being independently related to a 1.35 m/s increase in pulse wave velocity. We conclude that aortic stiffness is increased in HIV-positive individuals receiving antiretroviral therapy including a protease inhibitor. Pulse wave velocity increases with longer exposure to protease inhibitors. We hypothesize that arteriosclerosis is a side effect of antiretroviral treatment including a protease inhibitor.
•
EASY: ADHERENCE TO THE NATIONAL CHOLESTEROL EDUCATION PROGRAM (NCEP) GUIDELINES IN SPECIALISED MEDICAL SETTINGS: OBSERVATIONAL STUDY
C. Schweiger 1 , C. Rapezzi 2 , A. Ceriello3, M. Velussi4 , R Bellis 5, M. Cafiero 6, T. Piliego7. l Ospedale Passirana di Rho-MI; 2Unic,ersit~'l di BologTm; 3 Unic,ersit~'l di Udine; 4 (~/sa di cura Pinem del (2o'so Trieste; 5 0spedale Loreato a Mare; 6Azienda Ospedaliera Monadi, Napoli; 7AstmZeneca Italia Basiglio, Milano, Italy E-maih [email protected] Cardiovascular diseases are the leading cause of death in Western countries, despite the considerable improvement in mortality reduction due to atherosclerosis of coronary arteries. Hypercholesterolemia is undertreated in many patients, despite the presence of clear and scientific guidelines and despite the existence of well tolerated hypolipemic drugs. The observational EASY study aimed to provide information on adherence to NCEP guidelines in specialised medical settings and to evaluate the percentage of patients treated with lipid-lowering drugs aJnd how many of these patients reached the NCEP 2001 LDL target. 277 specialistic centers (Cardiology, Diabetology, Internal Medicine) were selected to participate in the study. Data collection was performed in Spring 2004; consecutive patients were studied without selection criteria. 15,457 patients, middle age 63 years, were studied. Dislipidemic patients diagnosed according to values suggested by NCEP were 7236 (70% treated with statins). Despite this good treatment percentage compared with other studies, LDL-C target was reached only in 33.5% of treated patients. Considering high risk patients (LDL-C targe < 100 mg/dL) the target was reached in 28.4%. Conclusions: LDL target was not reached in 66% of dislipidemic patients and in 72% of high risk patients, suggest among possible explanation, underestimation of patients risk level by physicians mad utilisation of non efficacious lipid-lowering drugs.
•
ADAPTOR PROTEIN ARH MODULATES THE ENDOCYTOSIS OF LDL-LDLR COMPLEXES IN HEPATOCYTES
M.I. Sirinian1 , E Belleudi2'3, E Campagna 1 , M. Ceridono 2, T. Garofalo 2, E Quagliarini1'2, R. Verna 2, S. Calandra4, S. Bertolini 5, M. Sorice 2, M.R. Torrisi2'3, M. Arca 1 . 1Dept of (Tinical and Applied Medical Therapy, 2Evperimenml Medicine and Pathology, 3Azienda spedaliem Sant 'Andrea, Unic~ La Sapienza, Rome; 4Dept of Biomedical Sciences, Unic~ of Modena atM Reggio Emilia, Modena; 5Dept of Inte~vtal Medicine, Unic,ersiO~ of Genoa, Italy E-maih [email protected] ARH is a newly discovered adaptor protein required for the efficient activity of low density lipoprotein receptor (LDLR). Individuals lacking ARH have severe hypercholesterolemia due to an impaired hepatic clearance of LDL. However, the function of ARH in liver cells is not completely understood. Thus, we investigated by immunofluorescence and Western blotting, the involment of ARH in the endocytosis of L D L L D L R complexes in HepG2 cells before and after transient loss of ARH by short interference RNA (siRNA) methodology. ARH was found to be codistributed with LDLR on the basolateral area in confluent HepG2 polarized cells and this was not modified by the overexpression of LDLR. Conversely, the activation of the LDLR-mediated endocytosis promoted a significant colocalization of ARH with the LDL/LDLR complex that peaked at 2 m i n at 37°C. Transient loss of ARH by siRNA resulted in the failure of LDL to be endocytosed and the almost complete absence of the LDL LDLR complex in the internal compartment of hepatocytes. By immunoprecipitation, ARH appeared to be associated with other proteins of the endocytic machinery. In conclusion, we suggest that ARH may function as an endocytic sorting adaptor that modulates the internalization of the LDL-LDLR complex, possibly enhancing the efficiency of its packaging into the endocytic vesicles.
[•
USEFULLNESS OF EZETIMIBE IN HYPERLIPIDEMIC OUTPATIENTS
M Spagnuolo 1 , M. Ferraro 2 , F. Fiorentino 1 , G.E Mauro 2 , C-E. Lieou 1 , P. Seng Long 1 , M. Poulain 1 , L. Tatem 1 . 1 UO di Medicina Inte~Tm ".4. Uosco" PO "Anmmz&m" ,40 di Uosenza, 2UO di Medicina Inte~Tm PO di San Gioc,anni in Fiore ((5) ASL di O'otone, Italy; 3 Unic,ersitO Renk Descartes Paris V Facultk de Pha?vtacie, France E-maih vitaliaJnos @yahoo. com Ezetimibe (E) it is a new hypolipidemic drug that inhibits the internal absorption of the cholesterol from enterocyte. Although, at the moment, E still is not registered in Italy however the use of E for the patients is possible when they do not benefit from other hypolipidemic therapies. We have evaluated the effectiveness of 10mg die of E in 16 out patient affected by hyperlipidemia. Of the 16 patients, 13 were affected by hypercholesterolemia and 3 by mLxed
Nutrition, Metabolism & Cardiovascular Diseases, Volume 15 (2005) Supplement i
moderate weight loss program may have some effects on both cytokines. The relationship between plasma adiponectin and IL-10 levels was analyzed in 64 android [body mass index (BMI) >28 and waist-to-hip ratio (WHR) ~>0.86] and 20 gynoid [BMI > 28 and WHR < 0.86] obese healthy women. Android obese women (49±14 years) had a mean BMI of 37.1±5.3, similar to that of gynoid obese (49±11 years; BMI: 33.4±2.6). Twenty non-obese control women (46±11 years, BMI: 25.2±2.2) were also studied. In 12 android obese women measurements were repeated after a 12-week period of diet (1200 kcal/d). Median adiponectin (5.2 [3.3-7.8] vs. 12.1 [9.7 13.9] andvs. 15.0 [12.6 18.2] ~tg/mL, p<0.0001) and IL-10 (1.8 [1.2-3.3] vs. 3.5 [2.9-4.3] and vs. 4.1 [3.5-4.8] pg/mL, p < 0.0001) levels were lower in android vs. gynoid and vs. non-obese women. Among android obese women, low adiponectin levels were independent predictors (p < 0.0001) of decreased IL-10 levels, independently of BMI, WHR or insulin resistance. No change either in adiponectin or in IL-10 levels was observed after body weight reduction (8±4kg, p < 0.01). Android obesity is associated with a down-regulation of IL-10, which is closely related to low adiponectin levels. However, anti-inflammatory status of obesity might require prolonged periods of energy-restricted diets to revert to normal.
•
INSULIN RESISTANCE AS A DETERMINANT OF PLATELET ACTIVATION IN OBESE WOMEN
F. SaJntilli1 , S. Basili2, G. Pacini 3, M.T. Guagnano 1 , M.R. Manigrasso 1 , L. Pescara 1 , G. Ciabattoni 1 , C. Patrono 4, G. Davi 1 . 1Uenter of Evcellence on Aging, Unic,ersiO, of (;~ieti "G. D 'Anmmzio "," 2Metabolic Unit, Institute of Biomedical Engineering, National Research Uouncil, Padoc,a; atM Departments of 3Medical Therapy arm 4Pha~vtacologv. Unic,ersiO~ of Rome "La Sapienza ". Italy E-mail: [email protected] Background: Obesity is associated with persistent platelet activation in otherwise healthy women. We tested the hypothesis that insulin resistance per se contributes to increased platelet activation in this setting. Methods and Results: We performed a cross-sectional study in 40 obese and 20 non-obese women using urinary thromboxane (TX) metabolite excretion as a non-invasive index of platelet activation. An index of insulin sensitivity, SI, was calculated and plasma adiponectin, C-reactive protein (CRP) and CD40 ligand (CD40L) levels were measured as potential determinants of increased platelet activation. Obese women had significantly higher 11-dehydro-TXB2 excretion rate (p < 0.0001), CRP (p < 0.0001) and CD40L levels (p < 0.0001) and lower SI (p < 0.002) and adiponectin (p < 0.01) than controls. On multiple regression analysis waist-tohip ratio (p < 0.05) and SI (p < 0.04) predicted 11-dehydro-TXB2 excretion, independently of adiponectin, inflammatory and lipid patterns. To investigate the cause effect relationship of these associations, we examined the effects of a 12-week weight loss program on urinary 11-dehydro-TXB2 in 10 obese women with impaired SI and visceral obesity. Successful weight loss achieved in 5 subjects was associated with an increase in SI (+92%) and a decrease in CD40L ( 2 7 % ) , CRP ( 3 7 % ) and ll-dehydro-TXB2 ( 5 3 % ) , (p<0.05). Conclusions: insulin resistance is a major determinant of platelet activation in female obesity.
•
IMPACT OF TREATMENT WITH PROTEASE INHIBITORS ON AORTIC STIFFNESS IN ADULT PATIENTS WITH HUMAN IMMUNODEFICIENCY VIRUS INFECTION
G. Savarese, G. Schillaci, G.VL. De Socio, M. Pirro, M.R. Mannarino, E Baldelli, G. Stagni, E. Mannarino. Medicina Inte~Tza, Angiologia e Malattie da Arteriosclerosi, Unic,ers&'l di Perugia, Italy E-mail: [email protected] The role of antiretroviral therapy in acceleration of atherosclerosis in patients with human immunodeficiency virus (HIV) infection is controversial. We hypothesized that aortic stiffness, an early marker of arteriosclerosis, may be increased in HIV patients treated with protease inhibitors. In 32 HIV-infected patients treated with protease inhibitors aJnd 32 age-, sex- aJnd blood pressure-matched HIV-uninfected control subjects, we obtained aortic pulse wave velocity and central aortic pressure waveform, from which aortic augmentation was calculated. HIV patients had a higher aortic pulse wave velocity (7.6±1.1 vs 6.8±l.2m/s, p 0.015) and aortic augmentation (6.8±5 vs 4.6±4mmHg, p 0.037) thaJn control subjects. Age and HIV infection (both p < 0.05) independently predicted aortic pulse wave velocity when a consistent number of cardiovascular risk factors was simultaneously controlled for. The cumulative duration of treatment was a predictor of aortic pulse wave velocity, each 5 years of treatment duration being independently related to a 1.35 m/s increase in pulse wave velocity. We conclude that aortic stiffness is increased in HIV-positive individuals receiving antiretroviral therapy including a protease inhibitor. Pulse wave velocity increases with longer exposure to protease inhibitors. We hypothesize that arteriosclerosis is a side effect of antiretroviral treatment including a protease inhibitor.
•
EASY: ADHERENCE TO THE NATIONAL CHOLESTEROL EDUCATION PROGRAM (NCEP) GUIDELINES IN SPECIALISED MEDICAL SETTINGS: OBSERVATIONAL STUDY
C. Schweiger 1 , C. Rapezzi 2 , A. Ceriello3, M. Velussi4 , R Bellis 5, M. Cafiero 6, T. Piliego7. l Ospedale Passirana di Rho-MI; 2Unic,ersit~'l di BologTm; 3 Unic,ersit~'l di Udine; 4 (~/sa di cura Pinem del (2o'so Trieste; 5 0spedale Loreato a Mare; 6Azienda Ospedaliera Monadi, Napoli; 7AstmZeneca Italia Basiglio, Milano, Italy E-maih [email protected] Cardiovascular diseases are the leading cause of death in Western countries, despite the considerable improvement in mortality reduction due to atherosclerosis of coronary arteries. Hypercholesterolemia is undertreated in many patients, despite the presence of clear and scientific guidelines and despite the existence of well tolerated hypolipemic drugs. The observational EASY study aimed to provide information on adherence to NCEP guidelines in specialised medical settings and to evaluate the percentage of patients treated with lipid-lowering drugs aJnd how many of these patients reached the NCEP 2001 LDL target. 277 specialistic centers (Cardiology, Diabetology, Internal Medicine) were selected to participate in the study. Data collection was performed in Spring 2004; consecutive patients were studied without selection criteria. 15,457 patients, middle age 63 years, were studied. Dislipidemic patients diagnosed according to values suggested by NCEP were 7236 (70% treated with statins). Despite this good treatment percentage compared with other studies, LDL-C target was reached only in 33.5% of treated patients. Considering high risk patients (LDL-C targe < 100 mg/dL) the target was reached in 28.4%. Conclusions: LDL target was not reached in 66% of dislipidemic patients and in 72% of high risk patients, suggest among possible explanation, underestimation of patients risk level by physicians mad utilisation of non efficacious lipid-lowering drugs.
•
ADAPTOR PROTEIN ARH MODULATES THE ENDOCYTOSIS OF LDL-LDLR COMPLEXES IN HEPATOCYTES
M.I. Sirinian1 , E Belleudi2'3, E Campagna 1 , M. Ceridono 2, T. Garofalo 2, E Quagliarini1'2, R. Verna 2, S. Calandra4, S. Bertolini 5, M. Sorice 2, M.R. Torrisi2'3, M. Arca 1 . 1Dept of (Tinical and Applied Medical Therapy, 2Evperimenml Medicine and Pathology, 3Azienda spedaliem Sant 'Andrea, Unic~ La Sapienza, Rome; 4Dept of Biomedical Sciences, Unic~ of Modena atM Reggio Emilia, Modena; 5Dept of Inte~vtal Medicine, Unic,ersiO~ of Genoa, Italy E-maih [email protected] ARH is a newly discovered adaptor protein required for the efficient activity of low density lipoprotein receptor (LDLR). Individuals lacking ARH have severe hypercholesterolemia due to an impaired hepatic clearance of LDL. However, the function of ARH in liver cells is not completely understood. Thus, we investigated by immunofluorescence and Western blotting, the involment of ARH in the endocytosis of L D L L D L R complexes in HepG2 cells before and after transient loss of ARH by short interference RNA (siRNA) methodology. ARH was found to be codistributed with LDLR on the basolateral area in confluent HepG2 polarized cells and this was not modified by the overexpression of LDLR. Conversely, the activation of the LDLR-mediated endocytosis promoted a significant colocalization of ARH with the LDL/LDLR complex that peaked at 2 m i n at 37°C. Transient loss of ARH by siRNA resulted in the failure of LDL to be endocytosed and the almost complete absence of the LDL LDLR complex in the internal compartment of hepatocytes. By immunoprecipitation, ARH appeared to be associated with other proteins of the endocytic machinery. In conclusion, we suggest that ARH may function as an endocytic sorting adaptor that modulates the internalization of the LDL-LDLR complex, possibly enhancing the efficiency of its packaging into the endocytic vesicles.
[•
USEFULLNESS OF EZETIMIBE IN HYPERLIPIDEMIC OUTPATIENTS
M Spagnuolo 1 , M. Ferraro 2 , F. Fiorentino 1 , G.E Mauro 2 , C-E. Lieou 1 , P. Seng Long 1 , M. Poulain 1 , L. Tatem 1 . 1 UO di Medicina Inte~Tm ".4. Uosco" PO "Anmmz&m" ,40 di Uosenza, 2UO di Medicina Inte~Tm PO di San Gioc,anni in Fiore ((5) ASL di O'otone, Italy; 3 Unic,ersitO Renk Descartes Paris V Facultk de Pha?vtacie, France E-maih vitaliaJnos @yahoo. com Ezetimibe (E) it is a new hypolipidemic drug that inhibits the internal absorption of the cholesterol from enterocyte. Although, at the moment, E still is not registered in Italy however the use of E for the patients is possible when they do not benefit from other hypolipidemic therapies. We have evaluated the effectiveness of 10mg die of E in 16 out patient affected by hyperlipidemia. Of the 16 patients, 13 were affected by hypercholesterolemia and 3 by mLxed