Biomedical subjects

Ilana Goldiner

Publications and source records attributed to Ilana Goldiner.

7 recordsLinked to original sources

PubMed2006

ABCA1-dependent but apoA-I-independent cholesterol efflux mediated by fatty acid-bile acid conjugates (FABACs).

FABACs (fatty acid-bile acid conjugates) are synthetic molecules that are designed to treat a range of lipid disorders. The compounds prevent cholesterol gallstone formation and diet-induced fatty liver, and increase reverse cholesterol transport in rodents. The aim of the present study was to investigate the effect of FABACs on cholesterol efflux in human cells. Aramchol (3beta-arachidylamido-7alpha,12alpha,5beta-cholan-24-oic acid) increased cholesterol efflux from human skin fibroblasts in a dose-dependent manner in the absence of known efflux mediators such as apoA-I (apolipoprotein A-I), but had little effect on phospholipid efflux. An LXR (liver X receptor) agonist strongly increased Aramchol-induced cholesterol efflux; however, in ABCA1 (ATP-binding cassette transporter A1)-deficient cells from Tangier disease patients, the Aramchol effect was absent, indicating that activity of ABCA1 was required. Aramchol did not affect ABCA1 expression, but plasma membrane levels of the transporter increased 2-fold. Aramchol is the first small molecule that induces ABCA1-dependent cholesterol efflux without affecting transcriptional control. These findings may explain the beneficial effect of the compound on atherosclerosis.

ATP Binding Cassette Transporter 1↗

PubMed2005

Biliary cholesterol crystallization characterized by single-crystal cryogenic electron diffraction.

Cholesterol crystals are the building blocks of cholesterol gallstones. The exact structure of early-forming crystals is still controversial. We combined cryogenic-temperature transmission electron microscopy with cryogenic-temperature electron diffraction to sequentially study crystal development and structure in nucleating model and native gallbladder biles. The growth and long-term stability of classic cholesterol monohydrate (ChM) crystals in native and model biles was determined. In solutions of model bile with low phospholipid-to-cholesterol ratio, electron diffraction provided direct proof of a novel transient polymorph that had an elongated habit and unit cell parameters differing from those of classic triclinic ChM. This crystal is exactly the monoclinic ChM phase described by Solomonov and coworkers (Biophysical J., In press) in cholesterol monolayers compressed on the air-water interface. We observed no evidence of anhydrous cholesterol crystallization in any of the biles studied. In conclusion, classic ChM is the predominant and stable form in native and model biles. However, under certain (low phospholipid) conditions, transient intermediate polymorphs may form. These findings, documenting single-crystal analysis in bulk solution, provide an experimental approach to investigating factors influencing biliary cholesterol crystal nucleation and growth as well as other processes of nucleation and crystallization in liquid systems.

Bile↗

PubMed2003

Method for the quantitative assay of fatty acid-bile acid conjugates by tandem mass spectrometry.

Fatty acid-bile acid conjugates and especially arachidyl amido cholic acid are synthetic molecules that were shown to prevent cholesterol gallstone formation in mice and hamsters as well as to dissolve pre-existing gallstones in mice. To measure these novel compounds we developed a liquid chromatography electrospray tandem mass spectrometry method based on the analysis of 100 microL of plasma with stearyl amido cholic acid (stamchol, 1.5 microM/L) added as internal standard. Repeatable calibrations between 0 and 50 microM/L exhibited consistent linearity and reproducibility. Inter- and intraassay C.V.s were 5.3-11.4% and 2.6-6.4%, respectively, at targeted concentrations of 0.1, 2.3 and 50 microM/L.

Animals↗

PubMed2003

Prevention of diet-induced fatty liver in experimental animals by the oral administration of a fatty acid bile acid conjugate (FABAC).

Fatty acid bile acid conjugates (FABACs) are a new family of synthetic molecules designed to solubilize biliary cholesterol. They were shown to prevent and dissolve cholesterol gallstones in inbred C57L/J mice fed a lithogenic, high-fat diet (HFD). In these mice, fatty liver was observed in the controls but not in the FABAC-treated ones. The present study was designed to study the effect of FABAC (arachidyl-amido-cholanoic acid) on diet-induced fatty liver in rats, hamsters, and mice. The fatty liver score (on a scale of 0-4 by light microscopy) was 4.0 in control hamsters and 0.3 in the FABAC-fed hamsters (P <.001). In mice it was 1.5 and 0.4, respectively (P <.01). The lipid/protein ratio in the liver was 1.3 +/- 0.44 (mg lipid/mg protein) in control rats and 0.66 +/- 0.04 in the FABAC group (P =.001) after 14 days. In hamsters it was 1.41 +/- 0.27 and 1.11 +/- 0.20, respectively (P =.03), after 21 days. In Imperial Charles River (ICR) mice the ratio was 0.34 +/- 0.10 and 0.17 +/- 0.07 (P =.03), respectively, after 24 days. Liver fat concentration, measured as mg lipid/g liver tissue, decreased similarly by FABAC feeding. The decrease in liver fat affected mainly the triglyceride levels. FABAC-fed animals gained weight similarly to the controls. Triglyceride absorption was unaffected by FABAC supplementation. In conclusion, oral FABAC therapy prevents/reduces the development of fatty liver in animals consuming a HFD.

Administration, Oral↗

PubMed2003

Biliary and systemic effects of fatty acid bile acid conjugates.

BACKGROUND: Fatty acid bile acid conjugates (FABACs) are novel synthetic molecules that solubilize cholesterol, prevent cholesterol crystal and gallstone formation, and dissolve pre-existing gallstones in mice. They are thus potential agents for gallstone prevention and treatment. The available knowledge concerning their biliary, systemic or possible toxic effects is, however, incomplete. AIM: To obtain information regarding biliary and systemic effects of FABACs. METHODS: Hamsters, rats and mice were administered C20-FABAC intragastrically, and serum and bile chemistries, organ histology, animal wellbeing, and survival were monitored. RESULTS: FABAC feeding (150 mg/kg/day) caused no adverse effects in any of the animal species studied. FABAC did not influence biliary cholesterol, phospholipid, or bile-salt concentrations in mice. In hamsters, biliary cholesterol concentration decreased slightly, but effects on phospholipids and bile salts were inconsistent. In some mouse strains, FABAC supplementation increased transaminases slightly. In hamsters and rats, transaminases were mainly unaffected or even decreased. Serum alkaline phosphatase, creatinine, albumin and glucose were generally unaffected by FABAC feeding. No gross or histopathological differences between controls and FABAC-fed animals were noted in any of the organs investigated. CONCLUSIONS: C20-FABAC given at a pharmacological dose is safe and devoid of any significant toxic effects in three different animal species.

Animals↗

PubMed2002

Dissolution of cholesterol gallstones in mice by the oral administration of a fatty acid bile acid conjugate.

Gallstones, mostly cholesterol stones, affect some 15% of the population. Oral bile salts dissolve human cholesterol gallstones, but with low efficacy, and surgery remains the main therapeutic option. Fatty acid bile acid conjugates (FABACs) were shown to prevent formation of cholesterol gallstones in experimental animals. The aim of this study was to test whether these compounds could dissolve preexisting cholesterol gallstones via oral administration. Inbred, gallstone-susceptible C57J/L mice were given a lithogenic diet for 2 months, and the presence of gallstones was ascertained. The mice were then switched to a regular diet while part of them were given in addition C20-FABAC, by gavage, at a dose of 0.5 or 3 mg per animal per day. All mice tested had cholesterol gallstones after 2 months on the lithogenic diet. In study I, after 2 months on the regular diet, 3 of 4 (75%) of the controls had gallstones, whereas none of the 6 FABAC-fed animals (3 mg/d) had stones (P =.033). In study II, evaluating 2 FABAC doses, after 2 months on the regular diet, 8 of 8 (100%) of the controls had gallstones, which were found in 2 of 7 (28%) and 1 of 8 (12%) of the mice supplemented with 0.5 mg/d (P =.007) or 3 mg/d (P =.001) FABAC, respectively. On a molar basis, the dose of 0.5 mg FABAC is equivalent to 14 mg/kg/d of a bile acid. In conclusion, FABACs given orally can dissolve preexisting cholesterol gallstones in mice. This was accomplished with a dose of FABAC equivalent to the dose of bile acids used in human gallstone dissolution.

Administration, Oral↗

PubMed2002

Apolipoprotein-E genotype and the risk of developing cholelithiasis following bariatric surgery: a clue to prevention of routine prophylactic cholecystectomy.

BACKGROUND: Obesity and especially rapid weight loss following bariatric surgery are known risk factors for cholelithiasis. Since the risk may be high, prophylactic cholecystectomy has been advocated. Apolipoprotein (Apo) E, an important carrier protein in cholesterol metabolism and trafficking, is believed to play a role in gallstone pathogenesis. In particular, the Apo E4 allele has been suggested to be associated with cholesterol cholelithiasis. The aim of this study was to assess the incidence of postoperative cholelithiasis in our patient population and to determine a possible correlation with the Apo-E genotype. METHODS: 134 morbidly obese patients undergoing gastric restrictive surgery [laparoscopic assisted gastric banding (LAGB) or silastic ring vertical gastroplasty (SRVG)] had abdominal ultrasound before and 6 to 12 months after operation, to determine the presence of gallstones. None of the patients enrolled in the study had gallstones before surgery. They did not have a prophylactic cholecystectomy or receive bile salt treatment. Apo-E genotypes were determined by Polymerase Chain Reaction restriction enzyme analysis. RESULTS: 10 patients (7.5%) developed postoperative cholelithiasis. The incidence of cholelithiasis in each ApoE genotype was: E2/E3--1/20 (5%), E3/E3--3/91 (3%), E3/E4--6/21 (29%), and E4/E4--0/2. ApoE allele frequencies in the study population were identical to those of a healthy control population. The mean BMI dropped from 43.6 to 29.4 kg/m2. CONCLUSIONS: The occurrence of postoperative gallstones was low in our population. However, in subjects with the Apo-E3/E4 genotype, the incidence is of practical significance. These data suggest that Apo-E genotyping may be useful in selecting patients for gallstone prevention (surgical or medical) when undergoing bariatric surgery. Further testing in larger patient populations may be able to give more definite guidelines in the future.

Adolescent↗