(Circulation. 1999;99:2571-2576.)
© 1999 American Heart Association, Inc.
Basic Science Reports |
Retroviral Gene Therapy in ApoE-Deficient Mice
ApoE Expression in the Artery Wall Reduces Early Foam Cell Lesion Formation
From the Departments of Pathology (A.H.H., S.F.), Medicine (M.F.L., S.J.B., V.R.B., L.A.G., S.F.), Pharmacology (M.F.L), Cell Biology (S.J.B), and Veterans Affairs (S.J.B), Vanderbilt University Medical Center, Nashville, Tenn.
Correspondence to Dr Sergio Fazio or Dr MacRae Linton, Division of Endocrinology, Vanderbilt University School of Medicine, 715 Medical Research Building II, Nashville, TN 37232-6303. E-mail sergio.fazio@mcmail.vanderbilt.edu or macrae.linton{at}mcmail.vanderbilt.edu
 |
Abstract |
|---|
 Top Abstract IntroductionMethodsResultsDiscussionReferences |
|---|
Background—Apolipoprotein E (apoE) has long been known to play an important role in the clearance of plasma lipoproteins. More recently, a direct role for apoE in delaying atherogenesis has been proposed. Macrophage production of apoE in the artery wall has been demonstrated to provide protection against atherosclerotic lesion development independently from its role in lipoprotein clearance. However, whether macrophage apoE can affect lesion growth at all stages of atherogenesis remains to be established.
Methods and Results—To evaluate the role of macrophage apoE in different stages of atherogenesis, as well as to establish a novel gene therapy approach to atherosclerotic vascular disease, we used an apoE-expressing retrovirus to transduce apoE-deficient (-/-) bone marrow for transplantation into apoE(-/-) recipient mice. Three weeks after bone marrow transplantation, apoE was expressed from arterial macrophages and was detectable in plasma associated with lipoproteins at 0.5% to 1% of normal levels but did not affect plasma cholesterol levels. We used 2 groups of recipient mice: younger mice with lesions consisting primarily of foam cells and older mice with more advanced lesions. When either the mouse or human apoE transgenes were expressed in mice from 5 to 13 weeks of age, there was a significant reduction in lesion area, whereas no effects were detected in mice that expressed apoE from 10 to 26 weeks of age.
Conclusions—We demonstrate that arterial macrophage apoE secretion can delay atherogenesis if expressed during foam cell formation but is not beneficial during the later stages of atherogenesis. These data also provide evidence that apoE transgene expression from arterial macrophages may have therapeutic applications.
Key Words: apolipoproteins • atherosclerosis • genes • cholesterol
|
Introduction |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
Apolipoprotein E (apoE) is a 34-kD glycoprotein that circulates on plasma lipoproteins and serves as the ligand for their receptor-mediated clearance.1 Although the majority of apoE is synthesized in the liver,2 it is also expressed in a number of other tissues3 by a wide variety of cell types, including tissue macrophages.4 In addition, secretion of apoE from the artery wall appears to protect against the development of atherosclerosis.5 6 7 Shimano et al5 demonstrated that diet-induced atheroma formation could be inhibited by expression of apoE from the artery wall in transgenic mice. Bellosta et al6 showed that the macrophage-specific expression of the human apoE3 transgene in apoE(-/-) mice results in smaller lesion area than that observed in control apoE(-/-) mice. Conversely, we have recently provided evidence that lack of macrophage-derived apoE promotes atherogenesis.7 In this study, wild-type mice given apoE(-/-) marrow transplants (which resulted in a macrophage-specific apoE knockout) had a 10-fold greater lesion area than did control mice. Although these studies demonstrate a direct role for macrophage-derived apoE in atherogenesis, they do not indicate the possible mechanism by which macrophage apoE functions, nor do they delineate which stage of atherosclerotic development can be affected by apoE. The present study was designed to express constitutively low levels of apoE from arterial macrophages targeting 2 different stages of atherosclerosis. Our hypothesis was that macrophage apoE exerts a measurable effect only during the macrophage-rich stage of lesion growth and functions less in modulating the later stages of atherosclerosis, when lesions are characterized by smooth muscle cell proliferation, extracellular cholesterol clefts, and areas of necrosis and calcification. To this end, we used an approach of transduction of apoE(-/-) bone marrow with apoE-containing retroviral constructs, followed by transplantation of marrow into apoE(-/-) recipient mice. Here, we report that transplantation of apoE(-/-) mice with apoE-transduced bone marrow leads to the expression of apoE from arterial macrophages and that local low-level expression of apoE in the artery wall is capable of delaying foam cell formation but has no effect on later stages of atherosclerosis. These studies support the concept that macrophage apoE secretion is important in the early foam cell formation stage of atherogenesis and that apoE transgene expression from arterial macrophages may have therapeutic applications.
|
Methods |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
Cloning of Mouse and Human ApoE cDNA Into the pLXSN Retroviral Vector
Mouse apoE cDNA (exons 2 to 4) was amplified by reverse transcription–polymerase chain reaction. Random hexamers were used for the reverse-transcription portion of the reaction. Human apoE3 was amplified from an expression vector driven by the cytomegalovirus promoter.8 Cycling conditions for both the mouse and human apoE consisted of 40 cycles of 97°C for 30 seconds, 62°C for 2 minutes, and 72°C for 2 minutes. The polymerase chain reaction products were used for ligation into the pLXSN retroviral vector and transfected into DH5
cells. Plasmid DNA from colonies was
prepared and analyzed for the presence of the 1-kb apoE cDNA
inserts. Plasmid DNA was prepared with the Plasmid Maxi kit obtained
from Qiagen according to kit protocol. The sequence of the apoE cDNA
inserts was confirmed by use of the ThermoSequenase kit (Amersham).
Preparation of Producer Cell Lines
The retroviral constructs were used to transfect the ecotropic
packaging cell line Bosc-23, which has been shown to result in
transient high-titer production of infectious
virus.9 The infectious supernatant from these cells was
used to infect the amphotropic packaging cell line
PA317.10 The infectious medium from this cell line was
then used to infect the ecotropic packaging cell line 
2 in a
transinfection or "ping-pong-ping" method for creating high-titer
producer cell lines.11 The infected 2 cells were
selected for the integration of the provirus with the neomycin analogue
G418 (Sigma) at 500 µg/mL. Individual clones were isolated and
analyzed for apoE expression and infectious titer. Individual
producer cell clones were analyzed for viral titer as well as
apoE secretion. Mouse apoE–expressing (pLMESN/2), human
apoE–expressing (pLHESN/2), and parental (pLXSN/2) producer
cells were selected for use in bone marrow transplant experiments. The
producer cell lines used for bone marrow transplantation (BMT) studies
were assayed for the presence of recombinant wild-type virus by the
S+ L-
assay12 13 and were found to be helper virus–free.
Bone Marrow Collection, Transduction, and Transplantation
Bone marrow was collected from apoE(-/-) donor mice by
flushing femurs and tibias with RPMI 1640 with 2% FBS and 10 U/mL
heparin (Sigma) added. Cells were washed, counted, and plated in
suspension dishes, where proliferation was stimulated by preculturing
with interleukin 3 (IL-3) and interleukin 6 (IL-6). IL-3 and IL-6 were
produced by transfection of COS-7 cells (ATCC) with
pCD-mIL314 and pCD-mIL6.14 15 Bone
marrow cells were precultured by plating 5x106
cells in 10 mL of DMEM, 10% FBS, 3% IL-3, 3% IL-6 COS-7 medium for
48 hours. After preculture, bone marrow cells were collected and
replated at the same density in the above medium with 6 µg/mL
hexadimethrine bromide (Sigma) onto dishes of 80% confluent producer
cells for 48 hours. The suspended bone marrow cells were then collected
and used to transplant lethally irradiated apoE(-/-) mice as
previously described.16
Animal Procedures and Lipid Analyses
All mice used for these experiments were apoE(-/-) at the
sixth backcross or higher into the C57BL/6 background and were
originally purchased from Jackson Laboratories, Bar Harbor, Me.
Mice were maintained in microisolator cages on a rodent chow diet (PMI
No. 5010) containing 4.5% fat. All mice were given autoclaved water
acidified to pH 2.6. One week before and 2 weeks after BMT, 100 mg/L
neomycin (Sigma) and 10 mg/L polymyxin B sulfate (Sigma) were added to
the acidified water. Blood samples were collected by retro-orbital
venous plexus puncture with heparinized tubes, and serum was separated
by centrifugation. Serum cholesterol and
triglyceride levels were determined with clinical
reagents on a microtiter plate assay, as previously
described.17 A 100-µL aliquot of serum from mice was
separated by Superose 6 chromatography on a Waters
high-performance liquid chromatography system
model 600 as described.18 Animal care and experimental
procedures were performed according to the regulations of Vanderbilt
University's Animal Care Committee.
Western Blotting and Immunohistochemical Analysis for
ApoE
Serum samples were tested for the presence of mouse or human
apoE by Western blot analysis as described.19 The
primary antibodies used were polyclonal rabbit anti-mouse apoE
(BioDesign International) and polyclonal goat anti-human apoE
(BioDesign). Similar Western blot analyses were performed on
fast protein liquid chromatography samples after
concentration of pooled fractions by centrifugation
with Microcon-10 columns (Amicon). Immunocytochemical analysis
of tissue samples for macrophages and mouse apoE was performed
essentially as described.7 Briefly, 5-µm sections were
fixed in acetone and incubated with either a rat monoclonal antibody to
macrophages, MOMA-2 (Accurate Chemicals), or a rabbit
polyclonal antibody to mouse apoE (BioDesign International). Signal was
detected with the ABC kit (Vector Laboratories) followed by incubation
with the fast red TR/naphthol As-NX substrate (Sigma). Photomicroscopy
was performed on a Zeiss Axiophot with Plan-FLUAR objectives.
Primary Macrophage Cultures
Peritoneal cells were collected 2 days after injection of
thioglycollate as described,20 counted, and plated into
12-well dishes at 1x106 cells/well in DMEM+10%
FBS. After 2 hours, nonadherent cells were removed. Wild-type, C57BL/6
mouse peritoneal leukocytes collected and plated in the same manner
served as a positive control. Medium was collected from
macrophages at 48-hour intervals and frozen in 1 mmol/L
PMSF for Western blot analysis.
Lesion Area Quantification
Experiments were designed in 2 parts: (1) male 5-week-old
apoE(-/-) mice killed at 13 weeks and (2) female 10-week-old
apoE(-/-) mice killed at 26 weeks. Atherosclerosis
studies in apoE(-/-) mice have not demonstrated any sex
differences in extent of lesion formation.21 Frozen
sections 10 µm thick were cut from the region of the proximal
aorta starting from the end of the aortic sinus and continuing
distally, according to the technique of Paigen et al.22
Sections were stained with oil red O and counterstained with
hematoxylin. Quantification of lesion area was performed on 15 sections
per animal by digitizing morphometry and was reported in mean
µm2/section. Computer morphometry was performed
with the KS300 software by Kontron Elektronik on a Compaq Presario
9240. Statistical analyses were performed with both Student's
t test and the Mann-Whitney rank sum test comparing control
and experimental lesion area in both experiments.
|
Results |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
Reconstitution of ApoE(-/-) Mice With Transduced Marrow
Mouse apoE and human apoE were detected in the serum of experimental mice as early as 3 weeks post-BMT and were expressed at levels
0.5% to 1% and 5% of normal, respectively (Figure 1
). Levels of apoE in serum were
consistent between animals and over time. ApoE was expressed
for as long as 5.5 months post-BMT. Serum cholesterol and
triglycerides, measured pre-BMT and at 6 or 8 weeks
post-BMT, showed no significant changes from baseline
(Table). To evaluate whether recipients
of retrovirus-infected marrow developed immunity against the foreign
antigen (apoE), we performed a Western blot assay of mouse plasma using
the plasma of a retrovirus-infected mouse (pLMESN) as the primary
antibody source. No apoE was detected even on undiluted normal mouse
plasma when a 1:50 dilution of pLMESN plasma was used as antibody
source, suggesting that no anti-apoE immunoglobulins were present
in the plasma of retrovirus-infected mice (data not shown).
|
|
The distribution of serum lipoproteins in experimental and control mice
was similar to that in nontransplant apoE(-/-) mice as determined by
gel filtration chromatography (data not shown). Both
mouse and human apoE were found to be associated with lipoproteins,
with most of the apoE on the large VLDL and on IDL/LDL (Figure 2). ApoE was detected in HDL fractions on
longer exposures.
|
Evidence of Stem Cell Transduction
The prolonged apoE expression in transplant mice suggests that
pluripotent stem cells or early progenitor cells were transduced,
because the progeny of late-stage progenitors probably persist in
circulation for no more than 3 to 4 months.23 To
investigate whether stem cells had been transduced, a secondary
transplantation was performed. Bone marrow was collected from 3 of the
murine apoE–expressing mice 16 weeks post-BMT and transplanted into 6
lethally irradiated apoE(-/-) recipient mice. ApoE was detected in
serum at 3 months post-BMT in these secondary transplant mice,
providing further evidence for stem cell transduction in the original
transplants (Figure 3).
|
Analysis of ApoE Expression by Peritoneal and Arterial
Macrophages
ApoE expression in the medium of BMT macrophages was 0.5%
that of C57BL/6 macrophages (Figure 4). ApoE was also expressed from other
tissues, such as the spleen and the artery wall. Immunocytochemistry
analyses showed that apoE was secreted by arterial
macrophages of pLMESN/2 mice from the 5- to 13-week group
(Figure 5) as well as the 10- to 26-week
group (data not shown). These apoE-producing macrophages were
found throughout the plaques and at the valve cusps, but there was a
high degree of variability in apoE expression between individual
experimental mice. Of a total of 14 mice in the treated group of the
"late study," 2 showed apoE in 60% to 80% of the
arterial macrophages, 5 in 30% to 40%, and 6 in
10% to 20%, and 1 had undetectable apoE. This degree of variability
was similar to that observed in the mice of the "early" group, in
which significant effects on lesion growth were observed.
|
|
Quantification of Atherosclerosis
In mice that received transplants at 10 weeks of age and
were killed at 26 weeks of age, there were no significant differences
in the extent or distribution of lesions detected between the
experimental (mouse apoE, n=23) and control groups (n=21)
(186 282±97 333 versus 183 168±88 771
µm2±SEM, respectively). In contrast,
experimental mice given transplants of either murine (n=11) or human
(n=15) apoE at 5 weeks of age and killed at 13 weeks of age had
significantly smaller lesions than control mice (n=9) (4847±2410,
5294±2868, and 12 837±7166 µm2±SEM,
respectively) (Figure 6). The differences
between murine or human apoE–expressing mice and controls were
significant at the level of P<0.003 and
P<0.002, respectively (Student's t test and
Mann-Whitney rank sum test). There was no difference between mice that
expressed either murine or human apoE. By immunocytochemistry
analysis, no major differences in plaque composition were
detectable between treated and control groups in either study.
|
|
Discussion |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
In this study, we demonstrate that retroviral infection of bone marrow with an apoE-containing retrovirus leads to expression of the apoE transgene in apoE(-/-) mouse recipients of BMT, resulting in secretion of apoE by macrophages in the artery wall. ApoE was present in the serum of experimental mice for as long as 5.5 months after transplantation, at levels of
0.5% to 1% of normal, and was
associated with lipoproteins. ApoE was expressed by both splenic and
peritoneal macrophages, as well as by macrophages
within the artery wall of transplant mice. Finally, both human and
mouse apoEs were effective in reducing foam cell formation when
expressed during early atherogenesis but had no effect during later
stages of atherogenesis.
In the first experiment, mice received transplants at 5 weeks of age
and were followed up until 13 weeks. When normal marrow is used to
reconstitute apoE(-/-) mice, apoE is not detected in serum until 3
weeks post-BMT.16 Therefore, mice in the present study
expressed apoE only from 8 to 13 weeks of age (monocyte adhesion and
foam cell formation stages of atherogenesis). Although plasma lipid
levels were not affected by the intervention, mice that expressed
either mouse or human apoE had significantly smaller lesion area (2- to
7-fold) than controls (P<0.003, mouse apoE versus controls,
and P<0.002, human apoE versus controls). These data
demonstrate that low-level apoE expression from arterial
macrophages is able to modulate early atherogenic events even
when expressed for only a few weeks. The second group received
transplants at 10 weeks and were allowed to progress until 26 weeks.
The apoE in these mice was therefore expressed at the beginning and
well into the intermediate lesion formation stage. In these mice, low
levels of mouse apoE were expressed for a longer time than in the
younger group but had no apparent effect on lesion formation. These
data support the concept that apoE expression from macrophages
in the artery wall is important in the early stages of atherogenesis
but is not beneficial when delivered to more advanced lesions. The
difference in atherosclerosis between studies cannot be
ascribed to variations in apoE expression level or duration in
transplant mice. Dot blot assays using all the samples of all time
points from all mouse groups confirmed that in every instance, plasma
apoE levels were 
0.5% of normal (not shown). In addition, secondary
transplants using the marrow from retrovirus-infected mice from the
late experiment show that apoE was detectable in the plasma of apoE
null recipients of marrow from primary transplant mice, proving that
long-lived stem cells were transduced during the original procedure
(Figure 3
). Although we cannot exclude the possibility that the
lack of apoE effect on atherosclerosis in the mice of
the late experiment was specific for the female sex, previous work from
other investigators shows that progression and composition of
arterial plaques in apoE null mice is not significantly
different between sexes.21 24
Because no macrophage-specific promoter was used in
this study, it is possible that other bone marrow–derived cell lines
may have contributed to plasma apoE levels in reconstituted mice. The
question of which cell type expressed apoE in the retrovirus-infected
mice was indirectly addressed in a series of experiments comparing apoE
levels in plasma and in macrophage-conditioned medium of either
the retrovirus-infected apoE null mice (pLMESN) or apoE null mice that
received 2 different dilutions (5% and 10%) of C57BL/6 marrow in apoE
null marrow. Because the macrophage is the only apoE-producing
cell line derived from normal unmanipulated bone marrow, we used the
ratio between the densitometric readings of plasma and
macrophage medium apoE in normal transplant mice as a
comparative marker of the contribution of macrophages to plasma
apoE in retrovirus-infected mice. The data (not shown) are compatible
with the notion that 70% of apoE in the plasma of these mice is
derived from macrophages, whereas only 30% derives from other
leukocytes.
The beneficial effect of apoE in the artery wall may be a result of one
of several mechanisms: (1) the promotion of cholesterol
efflux from the cholesterol-loaded
macrophage25 ; (2) the facilitation of reverse
cholesterol transport from the artery wall26 ;
(3) the induction of remnant uptake through apoE-dependent pathways (as
explained by the secretion-capture hypothesis)27 ; or (4)
its local effects on inflammatory processes such as platelet
aggregation,28 leukocyte activation,29 30 or
growth factor sequestration (see Reference 31 for review).
It is interesting to note that the level of human apoE in serum was
higher than that of mouse apoE (Figure 1), but still no
reduction in serum cholesterol levels was observed.
Although human apoE3 binds to the murine LDL receptor with lower
affinity than mouse apoE, it was nonetheless as effective as mouse apoE
in reducing lesion area in transplant mice. These data suggest that the
mechanism of action of macrophage apoE in the artery wall is
not completely explained by its receptor-binding properties.
Gene therapy has been considered a promising alternative for treatment of cardiovascular diseases, such as restenosis and atherosclerosis.32 33 The majority of studies performed to date have focused on eliminating smooth muscle cell proliferation in vascular injury models of restenosis. Several different approaches have been taken using adenoviral vectors to deliver many different categories of genes, including oligonucleotides against proto-oncogenes,34 suicide genes,35 and genes affecting cellular proliferation.36 Although these studies have clearly demonstrated the potential for reducing smooth muscle cell proliferation after angioplasty procedures, they do not address the question of whether gene therapy for atherosclerosis might be possible. Endothelial cells, smooth muscle cells, and macrophages all contribute to atherogenesis and are potential target cells for gene therapy approaches. Because monocytes/macrophages are derived from bone marrow progenitors, can migrate into the vessel wall, and are involved in the very early events in atherogenesis, they are attractive targets for cell-mediated gene therapy of atherosclerosis.
This study clearly demonstrates that macrophage-derived apoE has a significant impact on foam cell formation but does not play a role in the later stages of atherogenesis, in which macrophages are no longer the principal cell type involved in the lesion formation. In addition, this study demonstrates the feasibility and efficacy of transduction of bone marrow followed by transplantation as a way to express transgenes from macrophages in the artery wall with potent effects on atherogenesis. ApoE represents only one of the many potential genes with therapeutic effects on atherosclerosis. Other genes related to lipoprotein metabolism, fibrinolysis, thrombosis, cell proliferation, and oxidation have a potential application for gene therapy of atherosclerosis if expressed from macrophages in the artery wall.
|
Acknowledgments |
|---|
This work was supported in part by American Heart Association Grant-in-Aid 95011450 and by National Institutes of Health grants HL-53989 and HL-57986. Alyssa Hasty was supported in part by an NIH Vascular Biology Training Grant. Dr Babaev was supported in part by an NIH Diabetes Research Training Grant. Dr Linton was partially supported by a Clinical Investigator Development Award from the NIH (HL-02925). Drs Fazio and Linton are Established Investigators of the American Heart Association.
Received September 1, 1998; revision received January 22, 1999; accepted February 4, 1999.
|
References |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
-
Mahley RW. Apolipoprotein E:
cholesterol transport protein with expanding role in cell
biology. Science. 1988;240:622–630.
[Abstract/Free Full Text]
-
Linton MF, Gish R, Hubl ST, Butler E, Esquivel C, Bry
WI, Boyles JK, Wardell MR, Young SG. Phenotypes of
apolipoprotein B and apolipoprotein E after liver transplantation.
J Clin Invest. 1991;88:270–281.
-
Blue M-L, Williams DL, Zucker S, Khan SA, Blum CB.
Apolipoprotein E synthesis in human kidney, adrenal gland, and liver.
Proc Natl Acad Sci U S A. 1983;80:283–287.
[Abstract/Free Full Text]
-
Basu SK, Brown MS, Ho YK, Havel RJ, Goldstein JL.
Mouse macrophages synthesize and secrete a protein resembling
apolipoprotein E. Proc Natl Acad Sci U S A. 1981;78:7545–7549.
[Abstract/Free Full Text]
-
Shimano H, Ohsuga J, Shimada M, Namba Y, Gotoda T,
Harada K, Katsuki M, Yazaki Y, Yamada N. Inhibition of diet-induced
atheroma formation in transgenic mice expressing
apolipoprotein E in the arterial wall. J Clin
Invest. 1995;95:469–476.
-
Bellosta S, Mahley R, Sanan D, Murata J, Newland D,
Taylor J, Pitas R. Macrophage-specific expression of
human apolipoprotein E reduces atherosclerosis in
hypercholesterolemic E-null mice. J Clin
Invest. 1995;96:2170–2179.
-
Fazio S, Babaev VR, Murray AB, Hasty AH, Carter KJ,
Gleaves LA, Atkinson JB, Linton MF. Increased
atherosclerosis in mice reconstituted with
apolipoprotein E null macrophages. Proc Natl Acad Sci
U S A. 1997;94:4647–4652.
[Abstract/Free Full Text]
-
Fazio S, Horie Y, Weisgraber KH, Havekes LM, Rall SC
Jr. Preferential association of apolipoprotein E Leiden with very low
density lipoproteins of human plasma. J Lipid Res. 1993;34:447–453.[Abstract]
-
Pear WS, Nolan GP, Scott ML, Baltimore D.
Production of high-titer helper-free retroviruses by transient
transfection. Proc Natl Acad Sci U S A. 1993;90:8392–8396.
[Abstract/Free Full Text]
-
Miller AD, Buttimore C. Redesign of retrovirus
packaging cell lines to avoid recombination leading to helper virus
production. Mol Cell Biol. 1986;6:2895–2902.
[Abstract/Free Full Text]
-
Mann R, Mulligan RC, Baltimore D. Construction of a
retrovirus packaging mutant and its use to produce helper-free
defective retrovirus. Cell. 1983;33:153–159.[Medline]
[Order article via Infotrieve]
-
Brandt SJ, Bodine DM, Dunbar CE, Nienhuis AW.
Dysregulated interleukin 6 expression produces a syndrome resembling
Castleman's disease in mice. J Clin Invest. 1990;86:592–599.
-
Bassin RH, Tuttle N, Fishinger PJ. Rapid cell culture
assay technique for murine leukaemia viruses. Nature. 1971;229:564–566.[Medline]
[Order article via Infotrieve]
-
Yokota T, Lee F, Rennick D, Hall C, Arai N, Mosmann T,
Nabel G, Cantor H, Arai K-I. Isolation and characterization of a mouse
cDNA clone that expresses mast-cell growth-factor activity in monkey
cells. Proc Natl Acad Sci U S A. 1984;81:1070–1074.
[Abstract/Free Full Text]
-
Chiu C-P, Moulds C, Coffman RL, Rennick D, Lee F.
Multiple biological activities are expressed by a mouse interleukin 6
cDNA clone isolated from bone marrow stromal cells. Proc Natl
Acad Sci U S A. 1988;85:7099–7103.
[Abstract/Free Full Text]
-
Linton MF, Atkinson JB, Fazio S. Prevention of
atherosclerosis in apoE deficient mice by bone marrow
transplantation. Science. 1995;267:1034–1037.
[Abstract/Free Full Text]
-
Fazio S, Lee Y-L, Ji Z-S, Rall SC Jr. Type III
hyperlipoproteinemic phenotype in
transgenic mice expressing dysfunctional apolipoprotein E. J
Clin Invest. 1993;92:1497–1503.
-
Linton MF, Fazio S. Bone marrow transplantation
normalizes lipid and lipoprotein levels in apolipoprotein E deficient
mice. Circulation. 1994;90(suppl I):I-133. Abstract.
-
Fazio S, Horie Y, Simonet WS, Weisgraber KH, Taylor JM,
Rall SC Jr. Altered lipoprotein metabolism in transgenic
mice expressing low levels of a human receptor-binding-defective
apolipoprotein E variant. J Lipid Res. 1994;35:408–416.[Abstract]
-
Cohn ZA, Benson B. The differentiation of mononuclear
phagocytes: morphology, cytochemistry, and biochemistry. J Exp
Med. 1965;121:153–170.
-
Reddick RL, Zhang SH, Maeda N.
Atherosclerosis in mice lacking apoE: evaluation of
lesional development and progression. Arterioscler Thromb. 1994;14:141–147.
[Abstract/Free Full Text]
-
Paigen B, Morrow A, Holmes PA, Mitchell D, Williams RA.
Quantitative assessment of atherosclerotic lesions in mice.
Atherosclerosis. 1987;68:231–240.[Medline]
[Order article via Infotrieve]
-
VanZant G, Thompson BP, Chen J-J. Differentiation of
chimeric bone marrow in vivo reveals genotype-restricted
contributions to hematopoiesis. Exp Hematol. 1991;19:941–949.[Medline]
[Order article via Infotrieve]
-
Tangirala RK, Rubin EM, Palinski W. Quantitation of
atherosclerosis in murine models: correlation between
lesions in the aortic region and in the entire aorta, and differences
in the extent of lesions between sexes in LDL receptor-deficient and
apolipoprotein E-deficient mice. J Lipid Res. 1995;36:2320–2328.[Abstract]
-
Mazzone T, Reardon C. Expression of heterologous human
apolipoprotein E by J774 macrophages enhances
cholesterol efflux to HDL3. J Lipid Res. 1994;35:1345–1353.[Abstract]
-
Basu SK, Goldstein JL, Brown MS. Independent pathways
for secretion of cholesterol and apolipoprotein E by
macrophages. Science. 1983;219:871–873.
[Abstract/Free Full Text]
-
Ji Z-S, Fazio S, Lee Y-L, Mahley RW. Secretion-capture
role for apolipoprotein E in remnant lipoprotein metabolism
involving cell surface heparan sulfate proteoglycans. J Biol
Chem. 1994;269:2764–2772.
[Abstract/Free Full Text]
-
Desai K, Bruckdorfer R, Hutton RA, Owen JS. Binding of
apoE-rich high density lipoprotein particles by saturable sites on
human blood platelets inhibits agonist-induced platelet
aggregation. J Lipid Res. 1989;30:831–840.[Abstract]
-
Kelly ME, Clay MA, Mistry MJ, Hsieh-Li HM, Harmony JA.
Apolipoprotein E inhibition of proliferation of
mitogen-activated T lymphocytes: production of
interleukin 2 with reduced biological activity. Cell
Immunol. 1994;159:124–139.[Medline]
[Order article via Infotrieve]
-
Clay MA, Anantharamaiah GM, Mistry MJ,
Balasubramaniam A, Harmony JA. Localization of a domain in
apolipoprotein E with both cytostatic and cytotoxic activity.
Biochemistry. 1996;34: 11142–11151.
-
Mazzone T. Apolipoprotein E secretion by
macrophages: its potential physiological
functions. Curr Opin Lipidol. 1996;7:303–307.[Medline]
[Order article via Infotrieve]
-
Nabel EG. Gene therapy for
cardiovascular disease. Circulation. 1995;91:541–548.
[Free Full Text]
-
Yla-Herttuala S. Gene therapy for
cardiovascular diseases. Ann Med. 1996;28:89–93.[Medline]
[Order article via Infotrieve]
-
Simons M, Edelman ER, DeKeyser J-L, Langer R, Rosenberg
RD. Antisense c-myb oligonucleotides inhibit
intimal arterial smooth muscle cell accumulation in vivo.
Nature. 1992;359:67–70.[Medline]
[Order article via Infotrieve]
-
Guzman RJ, Hirschowitz EA, Brody SL, Crystal RG,
Epstein SE, Finkel T. In vivo suppression of injury-induced vascular
smooth muscle cell accumulation using adenovirus-mediated transfer of
the herpes simplex virus thymidine kinase gene. Proc Natl Acad
Sci U S A. 1994;91:10732–10736.
[Abstract/Free Full Text]
-
Chang MW, Barr E, Seltzer J, Jiang J-Q, Nabel GJ, Nabel
EG, Parmacek MS, Leiden JM. Cytostatic gene therapy for vascular
proliferative disorders using a constitutively active form of Rb.
Science. 1995;267:518–522.
[Abstract/Free Full Text]
This article has been cited by other articles:
 |
|
 |
|
  Y. R. Su, J. L. Blakemore, Y. Zhang, M. F. Linton, and S. Fazio Lentiviral Transduction of ApoAI Into Hematopoietic Progenitor Cells and Macrophages: Applications to Cell Therapy of Atherosclerosis Arterioscler. Thromb. Vasc. Biol., August 1, 2008; 28(8): 1439 - 1446. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. D. Atkinson, K. R. Coenen, M. R. Plummer, M. L. Gruen, and A. H. Hasty Macrophage-derived apolipoprotein E ameliorates dyslipidemia and atherosclerosis in obese apolipoprotein E-deficient mice Am J Physiol Endocrinol Metab, February 1, 2008; 294(2): E284 - E290. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Fan, S. Qiu, C. D. Overton, P. G. Yancey, L. L. Swift, W. G. Jerome, M. F. Linton, and S. Fazio Impaired Secretion of Apolipoprotein E2 from Macrophages J. Biol. Chem., May 4, 2007; 282(18): 13746 - 13753. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. G. Yancey, W. G. Jerome, H. Yu, E. E. Griffin, B. E. Cox, V. R. Babaev, S. Fazio, and M. F. Linton Severely altered cholesterol homeostasis in macrophages lacking apoE and SR-BI J. Lipid Res., May 1, 2007; 48(5): 1140 - 1149. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. G. Yancey, H. Yu, M. F. Linton, and S. Fazio A Pathway-Dependent on ApoE, ApoAI, and ABCA1 Determines Formation of Buoyant High-Density Lipoprotein by Macrophage Foam Cells Arterioscler. Thromb. Vasc. Biol., May 1, 2007; 27(5): 1123 - 1131. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Lucic, Z. H. Huang, D. S. Gu, M. K. Altenburg, N. Maeda, and T. Mazzone Regulation of macrophage apoE secretion and sterol efflux by the LDL receptor J. Lipid Res., February 1, 2007; 48(2): 366 - 372. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Ranalletta, N. Wang, S. Han, L. Yvan-Charvet, C. Welch, and A. R. Tall Decreased Atherosclerosis in Low-Density Lipoprotein Receptor Knockout Mice Transplanted With Abcg1-/- Bone Marrow Arterioscler. Thromb. Vasc. Biol., October 1, 2006; 26(10): 2308 - 2315. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z. H. Huang, M. L. Fitzgerald, and T. Mazzone Distinct Cellular Loci for the ABCA1-Dependent and ABCA1-Independent Lipid Efflux Mediated by Endogenous Apolipoprotein E Expression Arterioscler. Thromb. Vasc. Biol., January 1, 2006; 26(1): 157 - 162. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. H. Hasty, M. R. Plummer, K. H. Weisgraber, M. F. Linton, S. Fazio, and L. L. Swift The recycling of apolipoprotein E in macrophages: influence of HDL and apolipoprotein A-I J. Lipid Res., July 1, 2005; 46(7): 1433 - 1439. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Fazio and M. F. Linton Interplay Between Apolipoprotein E and Scavenger Receptor Class B Type I Controls Coronary Atherosclerosis and Lifespan in the Mouse Circulation, June 28, 2005; 111(25): 3349 - 3351. [Full Text] [PDF]
|
|
|
|
|
|
R. L. Raffai, S. M. Loeb, and K. H. Weisgraber Apolipoprotein E Promotes the Regression of Atherosclerosis Independently of Lowering Plasma Cholesterol Levels Arterioscler. Thromb. Vasc. Biol., February 1, 2005; 25(2): 436 - 441. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Wientgen, F. E. Thorngate, S. Omerhodzic, L. Rolnitzky, J. T. Fallon, D. L. Williams, and E. A. Fisher Subphysiologic Apolipoprotein E (ApoE) Plasma Levels Inhibit Neointimal Formation After Arterial Injury in ApoE-Deficient Mice Arterioscler. Thromb. Vasc. Biol., August 1, 2004; 24(8): 1460 - 1465. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z. W.Q. Moore, B. Zhu, D. G. Kuhel, and D. Y. Hui Vascular Apolipoprotein E Expression and Recruitment from Circulation to Modulate Smooth Muscle Cell Response to Endothelial Denudation Am. J. Pathol., June 1, 2004; 164(6): 2109 - 2116. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Y. Ishida, K. R. Bailey, K. G. Duncan, R. J. Chalkley, A. L. Burlingame, J. P. Kane, and D. M. Schwartz Regulated expression of apolipoprotein E by human retinal pigment epithelial cells J. Lipid Res., February 1, 2004; 45(2): 263 - 271. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. J. Gough and E. W. Raines Gene therapy of apolipoprotein E-deficient mice using a novel macrophage-specific retroviral vector Blood, January 15, 2003; 101(2): 485 - 491. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Fazio, V. R. Babaev, M. E. Burleigh, A. S. Major, A. H. Hasty, and M. F. Linton Physiological expression of macrophage apoE in the artery wall reduces atherosclerosis in severely hyperlipidemic mice J. Lipid Res., October 1, 2002; 43(10): 1602 - 1609. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Bultel-Brienne, S. Lestavel, A. Pilon, I. Laffont, A. Tailleux, J.-C. Fruchart, G. Siest, and V. Clavey Lipid Free Apolipoprotein E Binds to the Class B Type I Scavenger Receptor I (SR-BI) and Enhances Cholesteryl Ester Uptake from Lipoproteins J. Biol. Chem., September 20, 2002; 277(39): 36092 - 36099. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Boucher, P. Liu, M. Gotthardt, T. Hiesberger, R. G. W. Anderson, and J. Herz Platelet-derived Growth Factor Mediates Tyrosine Phosphorylation of the Cytoplasmic Domain of the Low Density Lipoprotein Receptor-related Protein in Caveolae J. Biol. Chem., May 3, 2002; 277(18): 15507 - 15513. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. D. Harris, I. R. Graham, S. Schepelmann, A. K. Stannard, M. L. Roberts, B. L. Hodges, V. Hill, A. Amalfitano, D. G. Hassall, J. S. Owen, et al. Acute regression of advanced and retardation of early aortic atheroma in immunocompetent apolipoprotein-E (apoE) deficient mice by administration of a second generation [E1-, E3-, polymerase-] adenovirus vector expressing human apoE Hum. Mol. Genet., January 1, 2002; 11(1): 43 - 58. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Yoshida, A. H. Hasty, A. S. Major, H. Ishiguro, Y. R. Su, L. A. Gleaves, V. R. Babaev, M. F. Linton, and S. Fazio Isoform-Specific Effects of Apolipoprotein E on Atherogenesis: Gene Transduction Studies in Mice Circulation, December 4, 2001; 104(23): 2820 - 2825. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. K. Stannard, D. R. Riddell, S. M. Sacre, A. D. Tagalakis, C. Langer, A. von Eckardstein, P. Cullen, T. Athanasopoulos, G. Dickson, and J. S. Owen Cell-derived Apolipoprotein E (ApoE) Particles Inhibit Vascular Cell Adhesion Molecule-1 (VCAM-1) Expression in Human Endothelial Cells J. Biol. Chem., November 30, 2001; 276(49): 46011 - 46016. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. S. Major, D. E. Dove, H. Ishiguro, Y. R. Su, A. M. Brown, L. Liu, K. J. Carter, M. F. Linton, and S. Fazio Increased Cholesterol Efflux in Apolipoprotein AI (ApoAI)-Producing Macrophages as a Mechanism for Reduced Atherosclerosis in ApoAI(-/-) Mice Arterioscler. Thromb. Vasc. Biol., November 1, 2001; 21(11): 1790 - 1795. [Abstract] [Full Text] [PDF]
|
|
|