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PubMed2006

Adenovirus mediated IL-10 gene transfer to the airway of the rat lung for prevention of lung allograft rejection.

BACKGROUND: The ability to express genes with potential immunoregulatory capacity could reduce allograft rejection (AR). We examined the feasibility of transferring the viral interleukin-10 (vIL-10) gene into rat lungs by intra-bronchial instillation and the subsequent effects of delivered vIL-10 on acute lung AR. METHODS: First, the adenoviral beta-galactosidase vector (adv-beta-gal) particles were instilled into the airway of the rat lung and protein synthesis of beta-gal was examined by histochemical staining. Next, the ability of the adenoviral vIL-10 vector (adv-vIL-10) transfection to modify AR was examined in a highly histoincompatible rat lung transplant model (BN-->Lew). Donor left lungs were transfected with 3 x 10(8) pfu/0.3 mL of adv-vIL-10 (vIL-10 group) or adv-beta-gal (control group) 3 days before transplantation. On day 6 post-transplant, lung allografts were harvested and AR was graded histologically (stage 0-4). Several pathological categories of inflammation (perivascular, peribronchial, or peribronchiolar mononuclear infiltrates, edema, vasculitis, intraalveolar hemorrhage, and necrosis) were also examined and scored on a scale of 0-4 as previously described. RESULTS: A successful transgene protein synthesis by adv-beta-gal in alveolar epithelial cells and alveolar macrophages was confirmed by histochemical staining with X-gal. The vIL-10 group showed a trend toward an improved stage of AR (3.75 +/- 0.5 vs. 4.0 +/- 0), and also a decreased pathological scores for edema (3.5 +/- 0.6 vs. 4.0 +/- 0), intraalveolar hemorrhage (2.3 +/- 1.0 vs. 2.5 +/- 0.6) and necrosis (1.5 +/- 0.5 vs. 1.75 +/- 1.3) compared with the control group, however, the differences in any pathological scores between the two groups did not reach a statistical significance. CONCLUSIONS: 1. A successful transgene protein synthesis in alveolar epithelial cells was ensured by intra-bronchial instillation of an adenoviral vector encoding beta-galactosidase gene. 2. Transferring the vIL-10 gene into rat lungs by intra-bronchial instillation did not seem to reduce lung AR significantly, as opposed to the results of our previous experiments in a rat cardiac allograft model. This discrepancy may be explained by several potential factors including the immunogenecity of adenoviral vectors in conjunction with the nature of the lung more susceptible to immune response and inflammation.

Adenoviridae↗
PubMed1992

Nature and localization of avian lens glycogen by electron microscopy and Raman spectroscopy.

Electron microscopy confirms the presence of a high concentration of glycogen particles in the lens nuclear region of birds of flying habit such as the ring-neck dove and pigeon. This observation is consistent with Raman spectroscopy. The glycogen particles in the dove lens, which are approximately 35 nm in diameter, are classified as beta type particles. Although this type has been previously characterized by high rates of glycogen turnover in other tissues, its localization in the lens nucleus indicates that it may serve a structural function rather than as a storage depot of carbohydrate in the lens. In a comparative electron microscopy study, glycogen particles were not observed in the chicken lens.

Animals↗
PubMed2005

Persistence of high density lipoprotein particles in obese mice lacking apolipoprotein A-I.

Obese mice without leptin (ob/ob) or the leptin receptor (db/db) have increased plasma HDL levels and accumulate a unique lipoprotein referred to as LDL/HDL1. To determine the role of apolipoprotein A-I (apoA-I) in the formation and accumulation of LDL/HDL1, both ob/ob and db/db mice were crossed onto an apoA-I-deficient (apoA-I(-/-)) background. Even though the obese apoA-I(-/-) mice had an expected dramatic decrease in HDL levels, the LDL/HDL1 particle persisted. The cholesterol in this lipoprotein range was associated with both alpha- and beta-migrating particles, confirming the presence of small LDLs and large HDLs. Moreover, in the obese apoA-I(-/-) mice, LDL particles were smaller and HDLs were more negatively charged and enriched in apoE compared with controls. This LDL/HDL1 particle was rapidly remodeled to the size of normal HDL after injection into C57BL/6 mice, but it was not catabolized in obese apoA-I(-/-) mice even though plasma hepatic lipase (HL) activity was increased significantly. The finding of decreased hepatic scavenger receptor class B type I (SR-BI) protein levels may explain the persistence of LDL/HDL1 in obese apoA-I(-/-) mice. Our studies suggest that the maturation and removal of large HDLs depends on the integrity of a functional axis of apoA-I, HL, and SR-BI. Moreover, the presence of large HDLs without apoA-I provides evidence for an apoA-I-independent pathway of cholesterol efflux, possibly sustained by apoE.

Animals↗
PubMed2003

The beta-subunit of the protein-conducting channel of the endoplasmic reticulum functions as the guanine nucleotide exchange factor for the beta-subunit of the signal recognition particle receptor.

Cotranslational protein transport to the endoplasmic reticulum is controlled by the concerted interaction of three GTPases: the SRP54 subunit of the signal recognition particle (SRP) and the alpha- and beta-subunits of the SRP receptor (SR). SRbeta is related to ADP-ribosylation factor (ARF)-type GTPases, and the recently published crystal structure of SRbeta-GTP in complex with the binding domain of SRalpha suggested that SRbeta, like all ARF-type GT-Pases, requires a guanine nucleotide exchange factor (GEF) for function. Searching the sequence data base, we identified significant sequence similarity between the Sec7 domain of ARF-GEFs and the cytosolic domains of the beta-subunits of the two homologous heterotrimeric protein-conducting channels in yeast. Using a fluorescence nucleotide exchange assay, we show that the beta-subunits of the heterotrimeric protein-conducting channels function as the GEFs for SRbeta. Both the cytosolic domain of Sec61beta as well as the holo-Sec61beta, when part of the isolated trimeric Sec61p complex, function as the GEF for SRbeta, whereas the same Sec61beta, when part of the heptameric complex that facilitates posttranslational protein transport, is inactive as the GEF for SRbeta

Amino Acid Sequence↗
PubMed1999

The ribosome regulates the GTPase of the beta-subunit of the signal recognition particle receptor.

Protein targeting to the membrane of the ER is regulated by three GTPases, the 54-kD subunit of the signal recognition particle (SRP) and the alpha- and beta-subunit of the SRP receptor (SR). Here, we report on the GTPase cycle of the beta-subunits of the SR (SRbeta). We found that SRbeta binds GTP with high affinity and interacts with ribosomes in the GTP-bound state. Subsequently, the ribosome increases the GTPase activity of SRbeta and thus functions as a GTPase activating protein for SRbeta. Furthermore, the interaction between SRbeta and the ribosome leads to a reduction in the affinity of SRbeta for guanine nucleotides. We propose that SRbeta regulates the interaction of SR with the ribosome and thereby allows SRalpha to scan membrane-bound ribosomes for the presence of SRP. Interaction between SRP and SRalpha then leads to release of the signal sequence from SRP and insertion into the translocon. GTP hydrolysis then results in dissociation of SR from the ribosome, and SRP from the SR.

Animals↗
PubMed1963

Beta glucuronidase-rich cytoplasmic particles in androgen-stimulated mouse kidney. A cytobiochemical study.

Androgens produced by stimulating mouse testis with gonadotropic hormones cause a rise in renal beta-glucuronidase but not an increase in acid or alkaline phosphatase. All subcellular components increase in beta-glucuronidase activity, with a relatively greater increment in particulate enzyme as compared with that free in the cytoplasm (non-sedimentable). A small percentage of recovered beta-glucuronidase, acid phosphatase, and alkaline phosphatase is found in material which rises to the surface during centrifugation in sucrose media (fraction I). The specific activity of beta-glucuronidase and acid phosphatase in this fraction is normally quite high with respect to the homogenate, while that of alkaline phosphatase is not. On the other hand, the fraction I material from androgen-stimulated mice exhibits a further increase in specific activity with respect to beta-glucuronidase and not acid phosphatase. It thus appears that there is an independence in the behavior of individual enzymes in response to physiologic stimuli in spite of obvious morphologic proximity.

Acid Phosphatase↗
PubMed1990

Apolipoprotein C-I modulates the interaction of apolipoprotein E with beta-migrating very low density lipoproteins (beta-VLDL) and inhibits binding of beta-VLDL to low density lipoprotein receptor-related protein.

The binding of native rabbit beta-very low density lipoproteins (beta-VLDL) to the low density lipoprotein receptor-related protein (LRP) requires incubation with exogenous apolipoprotein (apo) E. Inclusion of a mixture of the C apolipoproteins in the incubation inhibits this binding. In the present study, the ability of the individual C apolipoproteins (C-I, C-II, and C-III) to block binding of beta-VLDL to the LRP was examined by measuring cholesteryl ester formation in mutant fibroblasts that lack low density lipoprotein receptors or by measuring binding to the LRP using ligand blotting. In each assay, both apoC-I and apoC-II inhibited binding; apoC-I was the more effective inhibitor. Apolipoprotein C-III had no effect on binding activity, regardless of its sialylation level. Binding of human apoE to rabbit beta-VLDL in the absence or presence of human apoC-I, apoC-II, and monosialo-apoC-III was also determined, by gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The results of these studies are consistent with a mechanism in which exogenous human apoE displaces the endogenous apoE and the beta-VLDL particle becomes enriched with apoE (by 4.2-fold in this study). At this higher apoE content, the beta-VLDL bound to the LRP. Inclusion of apoC-I, apoC-II, or apoC-III in the incubation mixture resulted in a differential displacement of apoE from the beta-VLDL; however, at the concentrations examined, only apoC-I and apoC-II were capable of displacing sufficient apoE to abolish binding to LRP.

Amino Acid Sequence↗
PubMed2003

The beta-subunit of the signal recognition particle receptor is a novel GTP-binding protein without intrinsic GTPase activity.

The beta-subunit of the signal recognition particle receptor (SRbeta), a member of the Ras family of small molecular weight GTPases, is involved in the targeting of nascent polypeptide chains to the protein translocation machinery in the endoplasmic reticulum membrane. We purified SRbeta from an expressing strain of Escherichia coli and investigated the properties of the isolated GTPase. We find that, unlike other Ras family GTPases, most SRbeta purifies bound to GTP, and SRbeta-bound GTP is not easily exchanged with solution GTP. SRbeta possesses no detectable GTPase activity. Although a stable interaction between SRbeta and ribosomes is observed, SRbeta is not stimulated to hydrolyze GTP when incubated with ribosomes or ribosome-nascent chains. A GTPase mutant harboring a mutation in a region predicted to be functionally important, based on observations made in related GTPases, binds GTP with faster kinetics and appears to be a less stable protein but otherwise displays similar properties to the wild-type SRbeta GTPase. Our results demonstrate that as an isolated GTPase, SRbeta functions differently from the Arf- and Ras-type GTPases that it is most closely related to by sequence.

Animals↗
PubMed1991

Staurosporine inhibits neutrophil phagocytosis but not iC3b binding mediated by CR3 (CD11b/CD18).

C receptor CR3 (iC3b-receptor, CD11b/CD18) plays an essential role in several phagocytic and adhesive neutrophil functions. Recent evidence suggests that stimulus-induced phosphorylation of the CR3 beta-chain, CD18, may mediate certain neutrophil functions by transiently converting the molecule to an activated state. Staurosporine, a protein kinase C inhibitor that blocks PMA-induced CD18 phosphorylation, was used to study the functional relevance of this event. Neutrophils adhered to glass were assayed for binding and phagocytosis of iC3b-opsonized sheep E (EC3bi) in the presence or absence of PMA and/or staurosporine. Binding of EC3bi was markedly increased, not only by PMA, but also by staurosporine and by a combination of both agents (three- to sevenfold). The enhancement of rosetting by staurosporine was likely caused by increased surface expression of CR3 via exocytosis of specific granular contents. In contrast, staurosporine alone did not stimulate phagocytosis of EC3bi and markedly inhibited PMA-induced phagocytosis. Staurosporine also inhibited phagocytosis of yeast beta glucan particles, a CR3 ligand that, in contrast to EC3bi, is bound and ingested without additional prior treatment with PMA. beta glucan phagocytosis was associated with a low level of CD18 phosphorylation. Staurosporine did not block phagocytosis in general, because this agent had relatively little effect on FcR-mediated phagocytosis. These data demonstrate that phagocytosis mediated by CR3 requires activation of CR3 via a staurosporine-sensitive pathway. Increased binding of EC3bi, a function of increased surface expression of CR3, does not require activation of CR3 by such a pathway, confirming previous evidence for the independence of these two phenomena. A direct role for CD18 phosphorylation in the activation of CR3 for phagocytosis is consistent with these data.

Alkaloids↗
PubMed2004

Histomorphometry of human sinus floor augmentation using a porous beta-tricalcium phosphate: a prospective study.

Tricalcium phosphate (TCP) has been historically a well-accepted material for bone augmentation. We examined the use of a porous beta-TCP (100%) in a split mouth model for sinus floor augmentation. Five patients were treated bilaterally, receiving 1-2 mm-sized beta-TCP particles (Cerasorb) on one side (test side) and autologous chin bone particles on the other (control) side. Four other patients were treated with a unilateral sinus floor augmentation using 100% beta-TCP (no controls). Biopsies of the augmented sites were taken at 6 months. Histomorphometry measurements were carried out in order to quantify bone augmentation at test and control sides. The average bone volume (BV) formed in the augmented sinus at the control side was 41% (32-56%) and 17% (9-27%) in the test side when all nine patients were included (statistically significant, P=0.04). When only the five bilateral patients were included, mean BV of the test side was 19% (13-27%), which was also significantly different from the control side (P=0.009). Osteoid formation tended to be higher in the test side biopsies (1.3%) than in the controls (0.3%) (marginally significant, P=0.1), indicating ongoing bone formation in the TCP material. The amount of lamellar bone at the test side was less than half the amount in the control side, indicating that remodelling had only recently started in the TCP-augmented side. The resorption surface, however, did not differ significantly between the two sides. These histological results indicate that Cerasorb is an acceptable bone substitute material for augmentation of the maxillary sinus. Due to the osteoconductive, but not osteoinductive properties of this material, the rate of bone formation is somewhat delayed in comparison to autologous bone.

Adult↗
PubMed2001

A novel model of murine mucopolysaccharidosis type VII due to an intracisternal a particle element transposition into the beta-glucuronidase gene: clinical and pathologic findings.

We describe the clinical and pathologic findings in a murine model of mucopolysaccharidosis VII (Sly disease) that arose spontaneously in the C3H/HeOuJ mouse strain. Affected gus(mps2J)/gus(mps2J) mice are deficient in beta-glucuronidase because of insertion of an intracisternal A particle element into intron 8 of the gus structural gene. This is the first model of a human lysosomal storage disease caused by an intracisternal A particle element insertion. Mice with the gus(mps2J)/gus(mps2J) genotype have < 1% of normal beta-glucuronidase activity and secondary elevations of other lysosomal enzymes. The phenotype includes shortened life-span, dysmorphic features, and skeletal dysplasia. Lysosomal storage of glycosaminoglycans is widespread and affects the brain, skeleton, eye, ear, heart valves, aorta, and the fixed tissue macrophage system. Thus the phenotypic and pathologic alterations in gus(mps2J)/gus(mps2J) mice are similar to those in patients with mucopolysaccharidosis VII. The finding of antibodies to beta-glucuronidase in some older gus(mps2J)/gus(mps2J) mice suggests the mice produce sufficient enzyme to elicit an immune response. The gus(mps2J)/gus(mps2J) model provides another well-defined genetic system for the study of the pathophysiology of mucopolysaccharidosis and for evaluation of experimental therapies for lysosomal storage diseases. The disease in gus(mps2J)/gus(mps2J) mice is less severe than that seen in the previously characterized B6.C-H2(bm1)/ByBir-gus(mps)/gus(mps) mouse model. Furthermore, unlike gus(mps)/gus(mps) mice, gus(mps2J)/gus(mps2J) mice are fertile and breed to produce litters, all of which are mucopolysaccharidosis VII pups. This feature makes them extremely useful for testing intrauterine therapies.

Animals↗
PubMed2002

Amyloid beta-protein affects cholesterol metabolism in cultured neurons: implications for pivotal role of cholesterol in the amyloid cascade.

Recently, we have found that alterations in cellular cholesterol metabolism are involved in promotion of tau phosphorylation (Fan et al. [2001] J. Neurochem. 76: 391-400; Sawamura et al. [2001] J. Biol. Chem. 276:10314-10319). In addition, we have shown that amyloid beta-protein (A beta) promotes cholesterol release to form A beta-lipid particles (Michikawa et al. [2001] J. Neurosci. 21:7226-7235). These lines of evidence inspired us to conduct further studies on whether A beta affects cholesterol metabolism in neurons, which might lead to tau phosphorylation. Here, we report the effect of A beta1-40 on cholesterol metabolism in cultured neurons prepared from rat cerebral cortex. Oligomeric A beta1-40 inhibited cholesterol synthesis and reduced cellular cholesterol levels in a dose- and time-dependent manner, while freshly dissolved A beta had no effect on cholesterol metabolism. However, oligomeric A beta had no effect on the proteolysis of sterol regulatory element binding protein-2 (SREBP-2) or protein synthesis in cultured neurons. Oligomeric A beta did not enhance lactate dehydrogenase (LDH) release from neuronal cells or decrease signals in the cultures reactive to 3,3'-Bis[N,N-bis(carboxymethyl)aminomethyl]fluorescein, hexaacetoxymethyl ester (calcein AM) staining, indicating that A beta used in this experiment did not cause neuronal death during the time course of our experiments. Since alterations in cholesterol metabolism induce tau phosphorylation, our findings that oligomeric A beta alters cellular cholesterol homeostasis may provide new insight into the mechanism underlying the amyloid cascade hypothesis.

Alzheimer Disease↗
PubMed1991

An ultrastructural study of beta-very low density lipoprotein uptake and transport by valvular endothelium of hyperlipidemic rabbits.

The uptake and transport of beta-VLDL by the aortic valvular endothelium of normal and hypercholesterolemic rabbits were studied in situ. The rabbits were fed either standard diet or standard diet supplemented with 0.5% cholesterol and 10% butter, for 1-20 weeks. Rabbit beta-VLDL was either radiolabeled with 125I or conjugated with colloidal gold (Au) (5 nm-diameter size). beta-VLDL-Au or [125I]-beta-VLDL was perfused in situ via left ventricle and maintained within heart and thoracic aorta for 15 to 60 min at 37 degrees C. Small pieces of aortic valve tissue were processed for electron microscopy or for electron microscopic autoradiography according to the lipoprotein probe used. beta-VLDL was taken and transported by the valvular endothelium of normal or hypercholesterolemic animals by endocytosis and transcytosis. As compared to normal animals, the endocytosis of beta-VLDL by the aortic valvular endothelium of hypercholesterolemic animals started to increase after 2-3 weeks of diet, being almost double in the 12th week of diet. Quantification of autoradiographic grains indicated a marked augmentation of beta-VLDL particles transcytosed by plasmalemmal vesicles of hypercholesterolemic animals as compared to normal. In the aortic valves of hyperlipidemic animals, the amount of beta-VLDL transported through the endothelium of fibrosa region was 3 times higher than that of spongiosa region of the same valve. The results showed that in hyperlipidemia, beta-VLDL transcytosis is generally markedly enhanced, in particular in lesion prone area.

Animals↗
PubMed2002

Cesium adsorption in hydrated iron oxide particles suspensions: an NMR study.

137Cs is an important component of nuclear waste which may pollute water. Its migration in natural environments is slowed down by adsorption on minerals. Cesium adsorption on akaganeite (beta-FeOOH) particles, dextran-coated ferrihydrite (5 Fe(2)O(3)-9H(2)O) particles, and ferritin in aqueous solutions is studied with (133)Cs nuclear magnetic resonance measurements. The longitudinal relaxation time (T(1)) of (133)Cs in the presence of such magnetic particles depends on whether the ions bind to the particle or not. T(1) of (133)Cs ions in aqueous solutions containing the same amount of magnetized particles will not depend on cesium concentration if relaxation is governed by diffusion (when cesium is not able to bind), but it will depend on cesium concentration if exchange governs relaxation (when cesium is able to bind). The method is successfully tested using TEMPO, a nitroxide stable free radical whose relaxation is due to diffusion. (133)Cs relaxation in solutions of ferritin, akaganeite, and dextran-coated ferrihydrite particles is found to result from a cationic exchange of cesium ions between particles surface and bulk ions, owing to adsorption. The effect of pH on (133)Cs relaxation in solutions of the particles is consistent with the adsorption properties of cations on hydrated iron oxides.

Adsorption↗
PubMed1983

Genetic control of lipid transport in mice. I. Structural properties and polymorphisms of plasma lipoproteins.

To examine genetic factors involved in mammalian lipid transport, we present a detailed analysis of the plasma lipoproteins of the mouse and a survey of these lipoproteins among different inbred strains for genetic variations. Plasma lipoproteins were separated by differential ultracentrifugation into three density fractions: with densities less than 1.006 g/ml, between 1.006 and 1.063 g/ml, and between 1.063 and 1.21 g/ml. On agarose gels, the d less than 1.006 g/ml fraction migrated as a single major band with pre-beta mobility and appeared to correspond to human very low density lipoproteins based on its lipid and protein composition. The intermediate density class was heterogeneous, containing particles with beta and alpha mobilities on agarose gels. The 1.063-1.21 g/ml density fraction exhibited a single alpha-migrating band on agarose gels, characteristic of high density lipoprotein in other mammalian plasma. Marked genetic variation was seen for lipoprotein mobilities among different inbred strains. In Swiss random bred mice, most of the apoprotein was in high density lipoprotein (104 mg/dl of plasma). Lower protein concentrations of 8.5 and 6.2 mg/dl were found in the d = 1.006-1.063 g/ml class and in the very low density lipoprotein, respectively. Proteins thought to be homologous to human apolipoproteins A-I, A-II, B, and E were identified on the basis of their distributions among the lipoprotein fractions, their molecular weights and isoelectric points and, for A-I, B, and E, by their cross-reactivities with antibodies prepared against purified rat apolipoproteins. Considerable structural and quantitative variations also exist among these apolipoproteins isolated from different inbred mouse strains. Our results provide a basis for the use of the mouse as a model system for the study of the genetic control of lipid transport.

Animals↗
PubMed1998

Remnant high density lipoprotein2 particles produced by hepatic lipase display high-affinity binding and increased endocytosis into a human hepatoma cell line (HEPG2).

We had previously shown that hepatic lipase plays a prominent role in promoting the generation of pre-beta HDL particles from triglyceride rich HDL2, leaving an alpha-HDL particle of decreased size that was named "remnant HDL2" [Barrans, A., et al. (1994) J. Biol. Chem. 269, 11572-11577]. Interestingly, this remnant HDL2 was rapidly cleared by the liver, suggesting a particularly high affinity of those remnant HDL2 for liver cells. In the present study, we attempted to characterize the interaction of remnant HDL2 with HepG2 cells, as compared to those of native triglyceride rich HDL2. Two main observations were made. First, while triglyceride rich HDL2 particles were able to bind only the low-affinity binding sites, the remaining particle generated after hepatic lipase lipolysis the remnant HDL2 was further able to bind to the high-affinity binding sites. Competition experiments indicate that these two remnant HDL2 binding sites were the same as the two HDL3 binding sites previously described [Barbaras, R., et al. (1994) Biochemistry 33, 2335-2340]. This is the first observation on the remodeling dependence of HDL binding onto hepatocytes. Second, following binding on those two binding sites, the remnant HDL2 were faster internalized and in higher amounts than the native triglyceride rich HDL2. All together, these observations suggest that the continuous remodeling of HDL induces different binding and internalization characteristics of the HDL particles and that the high-affinity HDL binding sites might trigger the internalization of apo HDL through the low-affinity binding sites.

Binding, Competitive↗
PubMed1994

Identification of apolipoprotein B-100 low density lipoproteins, apolipoprotein B-48 remnants, and apolipoprotein E-rich high density lipoproteins in the mouse.

Plasma lipoprotein fractions from inbred C57BL/6J mice and outbred ICR mice were prepared by sequential density ultracentrifugation using density ranges that were optimized for separating mouse lipoproteins, or by Superose 6 HR10/30 fast performance liquid chromatography (FPLC). The lipoproteins were characterized by migration behavior in agarose, apolipoprotein (apo) composition, lipid composition, and particle size distribution. Both sequential density ultracentrifugation and Superose 6 FPLC were adapted for the separation of lipoproteins from a single mouse. In the plasma of ICR and C57BL/6J mice, in contrast to human plasma, alpha-migrating high density lipoproteins (HDL) and beta-migrating low density lipoproteins (LDL) had overlapping density ranges. For example, beta-migrating apoB-100 LDL, slow pre-beta-migrating apoB-48 remnants, and alpha-migrating HDL1 were found together in the d 1.02-1.04 g/ml fraction. The d 1.04-1.06 g/ml fraction contained beta-migrating apoB-100 LDL and alpha-migrating HDL1. Large HDL1 that were found at d 1.02-1.06 g/ml were apoE-rich HDL1, characteristic of cholesteryl ester transfer protein-deficient mammals. The d 1.10-1.21 g/ml fraction, in addition to alpha-migrating HDL, included unique slow beta-migrating particles that contained apoE and apoA-I but was deficient in neutral lipids. These slow beta-HDL eluted in the same FPLC fractions as dense alpha-migrating HDL. Compared to ICR mouse plasma, C57BL/6J mouse plasma contained more LDL and less HDL1, which might contribute to the susceptibility of C57BL/6J and the resistance of ICR mice to the development of aortic fatty streak lesions when challenged with an atherogenic diet.

Animals↗