Elevated expression of ISY1, APOA-1, SYNE1, MTG1, and MMP10 at HCC initiation: HCC specific protein network involving interactions of key regulators of lipid metabolism, EGFR signaling, MAPK, and splicing pathways.

Identification of molecular regulators of hepatocellular carcinoma (HCC) initiation and progression is not well understood. We chemically induced HCC in male Wistar rats by administration of diethyl nitrosamine (DEN) and 2-acetylaminofluorene (2-AFF). Using 2D-electrophoresis and MALDI-TOF-MS/MS analyses, we characterized differentially expressed proteins in liver tissues at early stage of HCC progression. Using RT-PCR analysis, we quantified the mRNA expression of the characterized proteins and validated the transcript expression with tumor tissues of clinically confirmed HCC patients. Using bioinformatic tools, we analyzed a network among the introduced proteins that identified their interacting partners and analyzed the molecular mechanisms associated with signaling pathways during HCC progression. We characterized a protein, namely, pre-mRNA splicing factor 1 homolog (ISY1), which is upregulated at both transcriptome and proteome levels at HCC initiation, progression, and tumor stages. We analyzed the interacting partners of ISY1, namely, APOA-1, SYNE1, MMP10, and MTG1. Real-time PCR analysis confirmed elevated expression of APOA-1 mRNA at HCC initiation, progression, and tumor stages in animals undergoing tumorigenesis. The mRNA expression of the interacting partners was validated with tumor tissues of clinically confirmed liver cancer patients; the analysis revealed significant elevation in expression of transcripts. The transcriptome and proteome analyses complement each other and dysregulation in mRNA and protein expression of these regulators may play critical role in HCC initiation and progression.

CSL112 (Apolipoprotein A-I [Human]) Strongly Enhances Plasma Apoa-I and Cholesterol Efflux Capacity in Post-Acute Myocardial Infarction Patients: A PK/PD Substudy of the AEGIS-I Trial.

INTRODUCTION: Cholesterol efflux capacity (CEC) is impaired following acute myocardial infarction (AMI). CSL112 is an intravenous preparation of human plasma-derived apoA-I formulated with phosphatidylcholine (PC). CSL112 is intended to improve CEC and thereby prevent early recurrent cardiovascular events following AMI. AEGIS-I (ApoA-I Event Reducing in Ischemic Syndromes I) was a multicenter, randomized, double-blind, placebo-controlled, dose-ranging phase 2b study, designed to evaluate the hepatic and renal safety of CSL112. Here, we report an analysis of a pharmacokinetic (PK) and pharmacodynamic (PD) substudy of AEGIS-I. METHODS: AMI patients were stratified by renal function and randomized 3:3:2 to 4, weekly, 2-hour infusions of low- and high-dose (2 g and 6 g) CSL112, or placebo. PK/PD assessments included plasma concentrations of apoA-I and PC, and measures of total and ABCA1-dependent CEC, as well as lipids/lipoproteins including high density lipoprotein cholesterol (HDL-C), non-HDL-C, low density lipoprotein cholesterol (LDL-C), ApoB, and triglycerides. Inflammatory and cardio-metabolic biomarkers were also evaluated. RESULTS: The substudy included 63 subjects from AEGIS-I. CSL112 infusions resulted in rapid, dose-dependent increases in baseline corrected apoA-I and PC, which peaked at the end of the infusion (Tmax ≈ 2 hours). Similarly, there was a dose-dependent elevation in both total CEC and ABCA1-mediated CEC. Mild renal impairment did not affect the PK or PD of CSL112. CSL112 administration was also associated with an increase in plasma levels of HDL-C but not non-HDL-C, LDL-C, apoB, or triglycerides. No dose-effects on inflammatory or cardio-metabolic biomarkers were observed. CONCLUSION: Among patients with AMI, impaired CEC was rapidly elevated by CSL112 infusions in a dose-dependent fashion, along with an increase in apoA-I plasma concentrations. Findings from the current sub-study of the AEGIS-I support a potential atheroprotective benefit of CSL112 for AMI patients.

Dietary cholesterol and apolipoprotein A-I are trafficked in endosomes and lysosomes in the live zebrafish intestine.

Difficulty in imaging the vertebrate intestine in vivo has hindered our ability to model nutrient and protein trafficking from both the lumenal and basolateral aspects of enterocytes. Our goal was to use live confocal imaging to increase understanding of intestinal trafficking of dietary cholesterol and apolipoprotein A-I (APOA-I), the main structural component of high-density lipoproteins. We developed a novel assay to visualize live dietary cholesterol trafficking in the zebrafish intestine by feeding TopFluor-cholesterol (TF-cholesterol), a fluorescent cholesterol analog, in a lipid-rich, chicken egg yolk feed. Quantitative microscopy of transgenic zebrafish expressing fluorescently tagged protein markers of early, recycling, and late endosomes/lysosomes provided the first evidence, to our knowledge, of cholesterol transport in the intestinal endosomal-lysosomal trafficking system. To study APOA-I dynamics, transgenic zebrafish expressing an APOA-I fluorescent fusion protein (APOA-I-mCherry) from tissue-specific promoters were created. These zebrafish demonstrated that APOA-I-mCherry derived from the intestine accumulated in the liver and vice versa. Additionally, intracellular APOA-I-mCherry localized to endosomes and lysosomes in the intestine and liver. Moreover, live imaging demonstrated that APOA-I-mCherry colocalized with dietary TF-cholesterol in enterocytes, and this colocalization increased with feeding time. This study provides a new set of tools for the study of cellular lipid biology and elucidates a key role for endosomal-lysosomal trafficking of intestinal cholesterol and APOA-I. NEW & NOTEWORTHY A fluorescent cholesterol analog was fed to live, translucent larval zebrafish to visualize intracellular cholesterol and apolipoprotein A-I (APOA-I) trafficking. With this model intestinal endosomal-lysosomal cholesterol trafficking was observed for the first time. A new APOA-I fusion protein (APOA-I-mCherry) expressed from tissue-specific promoters was secreted into the circulation and revealed that liver-derived APOA-I-mCherry accumulates in the intestine and vice versa. Intestinal, intracellular APOA-I-mCherry was observed in endosomes and lysosomes and colocalized with dietary cholesterol.

Oral Apolipoprotein A-I Mimetic D-4F Lowers HDL-Inflammatory Index in High-Risk Patients: A First-in-Human Multiple-Dose, Randomized Controlled Trial.

A single dose of the apolipoprotein (apo)A-I mimetic peptide D-4F rendered high-density lipoprotein (HDL) less inflammatory, motivating the first multiple-dose study. We aimed to assess safety/tolerability, pharmacokinetics, and pharmacodynamics of daily, orally administered D-4F. High-risk coronary heart disease (CHD) subjects added double-blinded placebo or D-4F to statin for 13 days, randomly assigned 1:3 to ascending cohorts of 100, 300, then 500 mg (n = 62; 46 men/16 women). D-4F was safe and well-tolerated. Mean ± SD plasma D-4F area under the curve (AUC, 0-8h) was 6.9 ± 5.7 ng/mL*h (100 mg), 22.7 ± 19.6 ng/mL*h (300 mg), and 104.0 ± 60.9 ng/mL*h (500 mg) among men, higher among women. Whereas placebo dropped HDL inflammatory index (HII) 28% 8 h postdose (range, 1.25-0.86), 300-500 mg D-4F effectively halved HII: 1.35-0.57 and 1.22-0.63, respectively (P < 0.03 vs. placebo). Oral D-4F peptide dose predicted HII suppression, whereas plasma D-4F exposure was dissociated, suggesting plasma penetration is unnecessary. In conclusion, oral D-4F dosing rendered HDL less inflammatory, affirming oral D-4F as a potential therapy to improve HDL function.

MDCO-216 Does Not Induce Adverse Immunostimulation, in Contrast to Its Predecessor ETC-216.

PURPOSE: Aim of this study was to demonstrate that MDCO-216 (human recombinant Apolipoprotein A-I Milano) does not induce adverse immunostimulation, in contrast to its predecessor, ETC-216, which was thought to contain host cell proteins (HCPs) that elicited an inflammatory reaction. METHODS: Data were taken from a clinical trial in which 24 healthy volunteers (HV) and 24 patients with proven stable coronary artery disease (sCAD) received a single intravenous dose of MDCO-216, ranging 5-40 mg/kg. Additionally, whole blood from 35 HV, 35 sCAD patients and 35 patients requiring acute coronary intervention (aCAD group) was stimulated ex vivo with MDCO-216 and ETC-216. RESULTS: No inflammatory reaction was observed in HV and sCAD patients following MDCO-216 treatment, judging by body temperature, white cell counts, neutrophil counts, C-reactive protein, circulating cytokines (IL-6, TNF-α), and adverse events. In the ex vivo experiment, the geometric means (SD) of the ratio of MDCO-216 stimulated IL-6 over background levels were 0.8 (1.9), 0.7 (1.5), 1.0 (2.0) for respectively HV, sCAD, aCAD. The corresponding ETC-216 stimulated values were 15.8 (2.9), 9.5 (3.6), 3.8 (4.0). TNF-α results were comparable. Because many ETC-216 stimulated samples had cytokine concentrations >ULOQ, ratios were categorised and marginal homogeneity of the contingency table (MDCO-216 versus ETC-216) was assessed with the Stuart-Maxwell test. P-values were ≤0.0005 for all populations. CONCLUSIONS: MDCO-216 did not induce adverse immunostimulation in HV and sCAD patients, in contrast to ETC-216. Results from the ex vivo stimulation suggests the same holds true for aCAD patients.

Persistent changes in lipoprotein lipids after a single infusion of ascending doses of MDCO-216 (apoA-IMilano/POPC) in healthy volunteers and stable coronary artery disease patients.

BACKGROUND AND AIMS: Effects of single ascending doses of MDCO-216 on plasma lipid and lipoprotein levels were assessed in human healthy volunteers and in patients with stable coronary artery disease (CAD). METHODS: MDCO-216 was infused at a single dose of 5, 10, 20, 30 or 40 mg/kg over 2 h and blood was collected at 2, 4, 8, 24, 48, 168 and 720 h after start of infusion (ASOI). Lipoprotein lipids were assessed by FLPC and by 1H NMR. RESULTS: Plasma concentrations of free cholesterol (FC) displayed a rapid and dose-dependent rise, peaking at 8 h, but remaining above baseline until 48 h ASOI, whereas levels of esterified cholesterol (CE) increased at lower doses but not at higher doses, and even decreased below baseline at the highest dose. Plasma cholesterol esterification rate (CER) decreased with a first nadir between 4 and 8 h and a second nadir at 48 h ASOI. Taken over all subjects receiving MDCO-216, the increase in FC at 8 h correlated inversely with the drop in CER at 4 h but positively with the increase in basal and scavenger receptor class B type I (SR-BI)-mediated cholesterol efflux capacities at 2 h ASOI. Upon FPLC analysis, FC was found to increase first in high density lipoproteins (HDL) and very low density lipoproteins (VLDL) and later (at 48 or 168 h ASOI) in low density lipoproteins (LDL). CE initially decreased in LDL and HDL but after 24 h started to increase in VLDL and LDL whereas HDL-CE was still below baseline at 48 h. Phospholipids (PL) showed the same pattern as FC. Triglycerides (TG) also rose rapidly, most prominently in VLDL, but also in LDL and HDL. Apolipoprotein E (Apo-E) in VLDL increased at 4-8 h but returned to baseline at 24 h ASOI. 1H NMR analysis showed a rapid and dose-dependent increase in HDL particle size, peaking at 2 h and returning to baseline at 24 h, and a small increase in HDL particle concentration. After infusion of the 40 mg/kg dose, LDL and VLDL-particles also increased in number and size. CONCLUSIONS: A single administration of MDCO-216 caused rapid changes in lipid levels and lipoprotein composition, some of which persisted for at least 7 days.

ApoA-IMilano phospholipid complex (ETC-216) infusion in human volunteers. Insights into the phenotypic characteristics of ApoA-IMilano carriers.

Epidemiological studies support an inverse correlation between HDL-C and cardiovascular disease. However, low HDL-C levels do not always segregate with premature disease. These include, LCAT deficiency and the apolipoproteinA-IMilano (AIM) variant. AIM has a cysteine for arginine at position 173 in the otherwise cysteine free protein permitting AIM homodimerization and apoA-II heterodimerization. We relate the biochemical characteristics of low HDL-C phenotype AIM carriers to lipoprotein changes in humans administered recombinant dimeric AIM/palmitoyl-oleoyl phosphatidyl choline (ETC-216). Pharmacokinetic analysis of infused ETC-216 suggest a slow distribution of AIM into peripheral tissue and an extremely long terminal half-life in plasma. Following ETC-216 administration to normal human volunteers, an initial dose-dependent HDL-C elevation was observed. Thereafter, subjects transiently acquired a lipoprotein profile similar to that of AIM carriers, including reduced HDL-C and mild hypertriglyceridemia. The time-dependent changes in plasma lipids/lipoproteins may support an increased tissue cholesterol removing capacity of ETC-216. These findings provide mechanistic insight into the rapid removal of atheromatous plaques observed in humans, possibly linked to enhanced cholesterol removal capacity of ETC-216.

Effects of the high-density lipoprotein mimetic agent CER-001 on coronary atherosclerosis in patients with acute coronary syndromes: a randomized trial.

AIM: High-density lipoproteins (HDLs) have several potentially protective vascular effects. Most clinical studies of therapies targeting HDL have failed to show benefits vs. placebo. OBJECTIVE: To investigate the effects of an HDL-mimetic agent on atherosclerosis by intravascular ultrasonography (IVUS) and quantitative coronary angiography (QCA). DESIGN AND SETTING: A prospective, double-blinded, randomized trial was conducted at 51 centres in the USA, the Netherlands, Canada, and France. Intravascular ultrasonography and QCA were performed to assess coronary atherosclerosis at baseline and 3 (2-5) weeks after the last study infusion. PATIENTS: Five hundred and seven patients were randomized; 417 and 461 had paired IVUS and QCA measurements, respectively. INTERVENTION: Patients were randomized to receive 6 weekly infusions of placebo, 3 mg/kg, 6 mg/kg, or 12 mg/kg CER-001. MAIN OUTCOME MEASURES: The primary efficacy parameter was the nominal change in the total atheroma volume. Nominal changes in per cent atheroma volume on IVUS and coronary scores on QCA were also pre-specified endpoints. RESULTS: The nominal change in the total atheroma volume (adjusted means) was -2.71, -3.13, -1.50, and -3.05 mm(3) with placebo, CER-001 3 mg/kg, 6 mg/kg, and 12 mg/kg, respectively (primary analysis of 12 mg/kg vs. placebo: P = 0.81). There was also no difference among groups for the nominal change in per cent atheroma volume (0.02, -0.02, 0.01, and 0.19%; nominal P = 0.53 for 12 mg/kg vs. placebo). Change in the coronary artery score was -0.022, -0.036, -0.022, and -0.015 mm (nominal P = 0.25, 0.99, 0.55), and change in the cumulative coronary stenosis score was -0.51, 2.65, 0.71, and -0.77% (compared with placebo, nominal P = 0.85 for 12 mg/kg and nominal P = 0.01 for 3 mg/kg). The number of patients with major cardiovascular events was 10 (8.3%), 16 (13.3%), 17 (13.7%), and 12 (9.8%) in the four groups. CONCLUSION: CER-001 infusions did not reduce coronary atherosclerosis on IVUS and QCA when compared with placebo. Whether CER-001 administered in other regimens or to other populations could favourably affect atherosclerosis must await further study. Name of the trial registry: Clinicaltrials.gov; Registry's URL: http://clinicaltrials.gov/ct2/show/NCT01201837?term=cer-001&rank=2; TRIAL REGISTRATION NUMBER: NCT01201837.

Treatment with apolipoprotein A-1 mimetic peptide reduces lupus-like manifestations in a murine lupus model of accelerated atherosclerosis.

INTRODUCTION: The purpose of this study was to evaluate the effects of L-4F, an apolipoprotein A-1 mimetic peptide, alone or with pravastatin, in apoE-/-Fas-/-C57BL/6 mice that spontaneously develop immunoglobulin G (IgG) autoantibodies, glomerulonephritis, osteopenia, and atherosclerotic lesions on a normal chow diet. METHODS: Female mice, starting at eight to nine weeks of age, were treated for 27 weeks with 1) pravastatin, 2) L-4F, 3) L-4F plus pravastatin, or 4) vehicle control, followed by disease phenotype assessment. RESULTS: In preliminary studies, dysfunctional, proinflammatory high-density lipoproteins (piHDL) were decreased six hours after a single L-4F, but not scrambled L-4F, injection in eight- to nine-week old mice. After 35 weeks, L-4F-treated mice, in the absence/presence of pravastatin, had significantly smaller lymph nodes and glomerular tufts (PL, LP<0.05), lower serum levels of IgG antibodies to double stranded DNA (dsDNA) (PL<0.05) and oxidized phospholipids (oxPLs) (PL, LP<0.005), and elevated total and vertebral bone mineral density (PL, LP<0.01) compared to vehicle controls. Although all treatment groups presented larger aortic root lesions compared to vehicle controls, enlarged atheromas in combination treatment mice had significantly less infiltrated CD68+ macrophages (PLP<0.01), significantly increased mean alpha-actin stained area (PLP<0.05), and significantly lower levels of circulating markers for atherosclerosis progression, CCL19 (PL, LP<0.0005) and VCAM-1 (PL<0.0002). CONCLUSIONS: L-4F treatment, alone or with pravastatin, significantly reduced IgG anti-dsDNA and IgG anti-oxPLs, proteinuria, glomerulonephritis, and osteopenia in a murine lupus model of accelerated atherosclerosis. Despite enlarged aortic lesions, increased smooth muscle content, decreased macrophage infiltration, and decreased pro-atherogenic chemokines in L-4F plus pravastatin treated mice suggest protective mechanisms not only on lupus-like disease, but also on potential plaque remodeling in a murine model of systemic lupus erythematosus (SLE) and accelerated atherosclerosis.

Safety, pharmacokinetics, and pharmacodynamics of oral apoA-I mimetic peptide D-4F in high-risk cardiovascular patients.

Patients with coronary heart disease or equivalent risk received a single dose of 30, 100, 300, or 500 mg of unformulated D-4F (n = 8, each dose) or placebo (n = 8) under fasting conditions. An additional 10 patients received 500 mg (n = 8) or placebo (n = 2) with a low-fat meal. There were no significant trends in any safety parameter. D-4F was detectable in plasma at all doses with a T(max) of 30 min, 1 h, and 2 h for 30, 100, and > or = 300 mg, respectively. The area under the curve((0-t)) was 27.81 ng/hr/ml and 54.71 ng/hr/ml for the 300 mg and 500 mg dose groups, respectively, and 17.96 ng/hr/ml for the 500 mg dose given with food. HDL from each time point for each subject was tested for its ability to inhibit LDL-induced monocyte chemotactic activity in cultures of human aortic endothelial cells. The values obtained were normalized to 1.0 for LDL alone to obtain the HDL inflammatory index. This index significantly improved at 4 h at the 300 mg dose and at 2 h at the 500 mg dose compared with placebo (P < 0.05). There were no changes in plasma lipid or lipoprotein levels. We conclude that unformulated D-4F has low bioavailability that is improved under fasting conditions, and that a single dose of D-4F is safe and well tolerated and may improve the HDL anti-inflammatory index.

Perspectivas futuras / Future perspectives

A terapêutica das dislipidemias tem se voltado para a redução dos níveis de LDL-colesterol, por inibir a síntese endógena do colesterol ou por bloquear sua absorção, conseguindo-se, assim, maior alcance de metas, com fármacos cada vez mais potentes, especialmente quando usados em associação. Fibratos e ácido nicotínico, agindo preferencilamente sobre os triglicérides, promovem maiores aumentos de HDL-colesterol e, associados e associados às vastatinas, auxiliam na omitização do perfil lipídico. Apesar do grande impacto epidemiológico do HDL-colesterol no risco cardiovascular , estratégias específicas para atuar sobre o HDL não eram disponíveis até o momento. O torcetrapib, um inibidor da proteína de transferência de ésteres de colesterol, promove grandes elevações de HDL-colesterol especialmente em combinação com as estatinas. Terapias biológicas surgem como novas possibilidades e envolvem o uso de proteínas, DNA, anticorpos ou outras substâncias derivadas ou sintétizadas a partir de tecidos vivos com propósitos terapêuticos. O maior avanço em estudos clínicos se deu com a utilização de apolipoproteínas-miméticas, como a apolipoproteína AI Milano, uma variante recombinante de apo AI. Infusões de apo AI Milano reduziram o desenvolvimento da aterosclerose em modelos animais e em humanos. Outras estratégias, como a auto-imunização, formando anticorpos que neutralizam a proteína de transferência de ésteres de colesterol também estão sendo estudadas em ensaios clínicos. Terapia gênica para elevar os níveis de HDL-colesterol pela superexpressão de lecitina:colesterol-aciltransferase encontra-se em perspectiva, mas sua habilidade em prolongar a expressão gênica com segurança irá requerer o desenvolvimento de vetores adequados.

Short-term prognostic value of lipid measurements in patients with angina pectoris. The ECAT Angina Pectoris Study Group: European Concerted Action on Thrombosis and Disabilities.

We studied the role of various markers of lipid metabolism, hemostasis and inflammation in a two year follow-up of 3,000 patients with angina pectoris, during which time 106 patients experienced myocardial infarction or sudden coronary death. Low levels of high density lipoprotein (HDL) cholesterol and of apolipoprotein (apo) A-I were most strongly associated with increased coronary risk. The relative risk per standard deviation increase was 0.68 for HDL cholesterol (95% confidence interval 0.55 to 0.84) and 0.66 for apoA-I (0.54 to 0.81). These associations were independent of other coronary risk factors, other lipid measurements, hemostatic factors, and C-reactive protein (CRP). The associations of total and LDL cholesterol, triglycerides, apoB, and lipoprotein(a) with coronary events were not independent of HDL cholesterol or hemostatic factors. We conclude that HDL cholesterol or apoA-I, hemostatic risk factors, and CRP are important prognostic markers of coronary events in secondary prevention.

Acute effects of intravenous infusion of ApoA1/phosphatidylcholine discs on plasma lipoproteins in humans.

To investigate the metabolism of nascent HDLs, apoA1/phosphatidylcholine (apoA1/PC) discs were infused IV over 4 hours into 7 healthy men. Plasma total apoA1 and phospholipid (PL) concentrations increased during the infusions. The rise in plasma apoA1 was greatest in small prebeta-migrating particles not present in the infusate. Total HDL unesterified cholesterol (UC) also increased simultaneously. After stopping the infusion, the concentrations of apoA1, PL, HDL UC, and small prebeta HDLs decreased, whereas those of HDL cholesteryl ester (CE) and large alpha-migrating apoA1 containing HDLs increased. ApoB-containing lipoproteins became enriched in CEs. Addition of apoA1/PC discs to whole blood at 37 degrees C in vitro also generated small prebeta HDLs, but did not augment the transfer of UC from erythrocytes to plasma. We conclude that the disc infusions increased the intravascular production of small prebeta HDLs in vivo, and that this was associated with an increase in the efflux and esterification of UC derived from fixed tissues. The extent to which the increase in tissue cholesterol efflux was dependent on that in prebeta HDL production could not be determined. Infusion of discs also reduced the plasma apoB and apoA2 concentrations, and increased plasma triglycerides and apoC3. Thus, nascent HDL secretion may have a significant impact on prebeta HDL production, reverse cholesterol transport and lipoprotein metabolism in humans.

Effects of intravenous infusion of lipid-free apo A-I in humans.

Apolipoprotein (apo) A-I is the principal protein component of the plasma high density lipoproteins (HDLs). Tissue culture studies have suggested that lipid-free apo A-I may, by recruiting phospholipids (PLs) and unesterified cholesterol from cell membranes, initiate reverse cholesterol transport and provide a nidus for the formation, via lipid-poor, pre-beta-migrating HDLs, of spheroidal alpha-migrating HDLs. Apo A-I has also been shown to inhibit hepatic lipase (HL) and lipoprotein lipase (LPL) in vitro. To further study its functions and fate in vivo, we gave lipid-free apo A-I intravenously on a total of 32 occasions to six men with low HDL cholesterol (30 to 38 mg/dL) by bolus injection (25 mg/kg) and/or by infusion over 5 hours (1.25, 2.5, 5.0, and 10.0 mg.kg-1.h-1). The procedure was well tolerated: there were no clinical, biochemical, or hematologic changes, and there was no evidence of allergic, immunologic, or acute-phase responses. The 5-hour infusions increased plasma total apo A-I concentration in a dose-related manner by 10 to 50 mg/dL after which it decreased, with a half-life of 15 to 54 hours. Coinfusion of Intralipid reduced the clearance rate. The apparent volume of distribution exceeded the known extracellular space in humans, suggesting extensive first-pass clearance by one or more organs. No apo A-I appeared in the urine. Increases in apo A-I mass were confined to the pre-beta region on crossed immunoelectrophoresis of plasma and to HDL-size particles on size exclusion chromatography. Increases were recorded in HDL PL, but not in HDL unesterified or esterified cholesterol. Increases also occurred in LDL PL and in very low density lipoprotein cholesterol, triglycerides, and PL but not in plasma total apo B concentration. These results can all be explained by combined inhibition of HL and LPL activities. Owing to the effects that this would have had on HDL metabolism, no conclusions can be drawn from these data about the role of lipid-free apo A-I in the removal of PL and cholesterol from peripheral tissues in humans. The kinetic data suggest that the fractional catabolic rate of lipid-free apo A-I exceeds that of spheroidal HDLs and is reduced in the presence of surplus PL.

Apolipoprotein AI-derived pulmonary vascular amyloid in aged dogs.

Our studies confirm the common occurrence of a unique form of apolipoprotein AI (apoAI)-derived vascular amyloidosis in dogs that appears to be unrelated to other disease conditions, but is associated with aging. Vascular amyloid deposits were most frequently located within the intima and media of medium-sized pulmonary arteries, and were not confirmed in any other tissues. Pulmonary vascular amyloid immunoreactive with antiserum to purified N-terminal (1-71) canine apoAI amyloid protein was demonstrated retrospectively in 12.8% of necropsied dogs (N = 243) 10 years of age or older. In a subsequent expanded 1-year prospective study of necropsied dogs (N = 231) of all ages, apoAI-derived pulmonary vascular amyloid deposits were demonstrated in 0.7% of dogs < 10 years of age and in 22% of dogs 10 years of age or older. The incidence of this form of amyloid in dogs 10 years of age or older was significantly associated with advancing age (P < 0.00001). However, significant differences regarding gender, breed, or the frequency of selected common disease conditions were not observed when the dogs with apoAI-derived amyloid were compared with control dogs. The possibility that this new form of senile apoAI-derived amyloidosis is a manifestation of an age-associated aberration in apoAI metabolism or is related to a mutant form of apoAI is the subject of ongoing investigations.

Apoliproteínas A-I y B-100 y enfermedad coronaria comprobada angiográficamente

Objetivo : establecer la correlación de las apolipoproteínas (APO) A-I y B-100 séricas , con la enferemdad coronaria (EC) y su severidad. Método: estudio abierto, prospectivo y análitico en 52 pacientes sometidos a angiocoronariografía de abril a septiembre de 1991, tomando previamente muestra de sangre para medición de colesterol (CT), triglicéridos (TG), HDL, APO-AI y APO B-100 y determinación de LDL, índice aterogénico (IA), LDL/HDL y relación APO A1/B-100. Sitio : Servicio universitario de referencia de pacientes de atención terciaria. Principales resulatdos : 65.4 por ciento de los pacientes fueron hombres y 34.6 por ciento, mujeres; 67.3 por ciento tenían EC y 32.7 por ciento nola tenían. Entre los grupos con y sin EC hubo diferencia significativa en todas las variables medidas, especialmente en el CT, cuya media era de 210+-51 mg por ciento en el grupo sin EC y de 255+-48 mg por ciento en el grupo con EC (p=0.0006), y en la relación APO-AI/B-100, que fue de 2.08+-0.49 para el grupo sin EC y de 1.18+-0.51 para elgrupo con EC (p=0001). Entre hombres y mujeres fueron significativamente diferentes las la APO-AI (p=0.004) y la relación APO-AI/B-100 (p=0.003). Ninguna variable diferenció el grupo con EC leve del grupo sin EC, pero sí diferenciaron la ausencia de EC de lapresencia de EC moderada y severa el CT, APO-AI, APO-AI/B-100, IA y LDL/HDL. En la regresión lineal el grado EC pependió significativamente de APO-AI/B-100 (r=0.73, p<0.001), APO-B-100 (r+0.60, p<0.001), LDL/HDL (r=0.51, p<0.001) y CT (r=0.50, p=<0.001). En la regresión múltiple la presencia de EC dependió de la relación APO-AI/B-100 (r=0.73) y del colesterol total (r=0.50). Conclusiones : el índice APO-AI/B-100 mejoró de manera importante la correlación con la presencia de EC con respecto a las demás variables, no así la medición de APO-AI y B-100 por separado. Esta misma relación no discriminó la ausencia de EC de la EC leve, pero si la ausencia de EC de la EC moderada y severa.