- Email: [email protected]
Revisiting Old Players in the Revitalized Field of Cardiovascular Gene Therapy∗
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY ª 2015 BY THE AMERICAN COLLEGE OF CARDIOLOGY FOUNDATION PUBLISHED BY ELSEVIER INC.
VOL. 66, NO. 2, 2015 ISSN 0735-1097/$36.00 http://dx.doi.org/10.1016/j.jacc.2015.04.065
EDITORIAL COMMENT
Revisiting Old Players in the Revitalized Field of Cardiovascular Gene Therapy* Kiyotake Ishikawa, MD, Roger J. Hajjar, MD
S
ince its inception (1), clinical gene therapy has
actions have been well characterized in the cardio-
progressed substantially albeit slowly. The
vascular system. Heme oxygenase (HO)-1, a target
recent development of adeno-associated virus
protein in Hinkel et al. (4), was first identified in
(AAV) vectors has galvanized the field of gene therapy.
1968 (5), and this factor has been under continuous
These vectors have important characteristics that
investigation ever since in many organs throughout
make them safe and efficacious in various disease
the body. On the other hand, vascular endothelial
states. AAV vectors induce long-term and efficient
growth factor (VEGF)-B, evaluated in Woitek et al.
in vivo gene transduction in various organs, they do
(6), was first reported in 1996 (7,8), nearly 10 years
not produce a strong immune response, and they do
after the discovery of VEGF. This factor attracted
not integrate in the host DNA. Their ability to trans-
relatively little attention during the following years
duce the quiescent cells offers significant advantages
and its function remained incompletely defined.
over other gene therapy vectors for treating various
Recent advances in gene manipulation techniques
diseases (2). The recent success of clinical trials for
and genetic analysis revealed detailed information
Leber congenital amaurosis and hemophilia using re-
on the roles of these proteins in the heart. It seems
combinant AAV vectors has led to an increase in clin-
both HO-1 and VEGF-B have cardioprotective effects
ical translation of AAV-based gene therapy, including
and accordingly, a gene overexpression approach
in cardiovascular diseases. Another important feature
was tested in large animal models of cardiac
of AAV vectors is that there are several serotypes with
diseases using a cardiotropic AAV serotype 9.
each serotype having tropism to specific organs. Many
Hinkel et al. (4) focused on the anti-inflammatory
researchers are now consistently reporting efficacy of
profile of HO-1, evaluating the efficacy of HO-1 over-
AAV-mediated cardiac gene therapy in clinically rele-
expression in the setting of ischemia-reperfusion
vant animal models using their own gene targets and
injury. Although several drugs are reported to
delivery methods (3).
induce HO-1 activation and alleviate reperfusion
SEE PAGES 139 AND 154
injury (9), gene therapy holds an advantage of activating HO-1 specifically and, potentially, more effec-
In this issue of the Journal, 2 studies used gene
tively. In line with previous studies reporting the
transfer approaches to overexpress proteins whose
beneficial effects of HO-1 in protecting the heart from cardiac ischemia (10), the authors demonstrated the efficacy of AAV-mediated HO-1 overexpression for the first time in large animals. The study reports a sig-
*Editorials published in the Journal of the American College of Cardiology reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology. From the Cardiovascular Research Center, Icahn School of Medicine at
nificant reduction in infarct volume in HO-1 overexpressed pigs along with preserved left ventricular ejection fraction after 60 min of balloon-induced
Mount Sinai, New York, New York. This work is supported by the
ischemia followed by reperfusion. Although the
National Institutes of Health (NIH) (R01 HL117505 and HL119046), the
authors only examined the animals 24 h after the
National Heart, Lung, Blood Institute Program of Excellence in Nano-
ischemia-reperfusion injury, HO-1 has been shown to
technology Award (Contract HHSN268201000045C), NIH a P50 HL112324, and a Transatlantic Fondation Leducq grant. Both authors have reported
be protective even with permanent coronary occlu-
that they have no relationships relevant to the contents of this paper to
sion (11) and also inhibits cardiac remodeling at the
disclose.
chronic stages (12). Thus, a longer-term follow-up
Ishikawa and Hajjar
JACC VOL. 66, NO. 2, 2015 JULY 14, 2015:166–8
Revisiting Old Players in CV Gene Therapy
may have shown further benefit in the setting of
The authors modified the AAV delivery method to a
AAV’s long-term gene transduction.
more clinically practical intracoronary injection and
In the second study, Woitek et al. (6) focus on an
also tested this approach in dogs that were already
isoform of VEGF with a distinctive profile among its
developing heart failure. Strikingly, VEGF-B 167 gene
family. VEGF-B expression is highest in the heart
transfer at the middle of the pacing protocol ex-
and has only weak angiogenic effects in contrast to
hibited substantial preservation of left ventricular
other VEGFs (13). This protein seems to be a critical
ejection fraction and lowered end-diastolic pressure
prosurvival factor for vascular cells (14) and has
in the dogs receiving AAV9.VEGF-B 167. Although
similar protective effects on cardiomyocytes (15).
these results in a canine model of tachycardia-
AAV-mediated mouse VEGF-B 167 gene transfer pre-
induced heart failure are encouraging, this is a
served cardiac function and prevented the elevation
model with relatively acute disease progression that
of left ventricular end-diastolic pressure in a dog
decompensates within 28 days. For future clinical
model of tachy-pacing induced heart failure (6).
applications, further studies are necessary to vali-
Their work was an extension of a previous study by
date this therapy in more chronic models, using
the same group using a similar animal model (16).
human VEGF-B 167.
F I G U R E 1 Cardiac Gene Therapy Approaches Using AAV
Depending on the genes of interest, targeted phases of diseases differ. Conventional gene therapy mostly focuses on correcting the developed disease by gene transfer of down-regulated proteins, whereas the preventive approach is taken in the studies by Hinkel et al. (4) and Woitek et al. (6) in this issue of the Journal. AAV ¼ adeno-associated virus; HO-1 ¼ heme oxygenase-1; I-1c ¼ active form of protein phosphatase inhibitor 1; S100A1 ¼ calcium binding protein; SERCA2a ¼ cardiac sarcoplasmic reticulum Ca2þ ATPase pump; VEGF ¼ vascular endothelial growth factor.
167
168
Ishikawa and Hajjar
JACC VOL. 66, NO. 2, 2015 JULY 14, 2015:166–8
Revisiting Old Players in CV Gene Therapy
The 2 studies are inherently different from con-
studies. One very interesting approach used by Woitek
ventional cardiac gene therapy approaches that aim
et al. (6) is the disease-induced gene overexpression
to correct down-regulated/up-regulated genes in
using an atrial natriuretic factor promoter. Inducible
already developed diseases (Figure 1). Corrective
transgene regulation is extremely attractive because
therapies have included gene transfer of calcium
the gene expression can be controlled depending on
cycling protein including the cardiac sarcoplasmic
the disease activity, and can also be specific to the
reticulum Ca2þ ATPase pump (SERCA2a), the calcium
target organs. The atrial natriuretic factor promoter
binding protein S100A1, and the active form of pro-
would therefore turn on when the cardiac myocyte is in
tein phosphatase inhibitor 1 (I-1c) (17). Preventive
distress and be turned off when the myocyte is healthy.
therapies require treatment before disease progres-
A current limitation may be the lower transduction
sion because of the nature of the targeted genes. Both
efficacy as the authors reported, requiring a large
HO-1 and VEGF-B167 were effective at halting pro-
amount of vectors that might induce a T-cell response
gression of disease when administered before or at
in some of the patients.
the time of injury. Although disease prevention is
Despite the remaining issues that need to be solved
generally more efficient and effective compared with
before clinical translation occurs, therapeutic effi-
disease reversal, with current technology, it is very
cacies demonstrated in these 2 gene transfer studies
difficult to accurately predict whether or not an in-
using large animal models show that AAV-mediated
dividual patient will deteriorate. Advances in patient
cardiac gene therapy is maturing for clinical applica-
screening methods to identify high-risk profiles, such
tions. Advances in vector technology and gene de-
as genetic screening or induced-pluripotent stem
livery methods offer overexpression of not only novel
cell–mediated screening, may increase the value of
molecular targets but also well-known targets. It may
these preventive gene therapies.
be time to look back at some of the therapeutic targets
Unlike targeting genes already down-regulated
with “obsolete” labels.
in the disease setting, preventive gene therapy renders up-regulation of genes that are not usually
REPRINT REQUESTS AND CORRESPONDENCE: Dr.
activated in the normal setting. This may lead to un-
Roger J. Hajjar, Cardiovascular Research Center,
expected results in humans where complex molecular
Mount Sinai School of Medicine, One Gustave L. Levy
interactions are present and potentially longer expo-
Place, Box 1030, New York, New York 10029-6574.
sure to the overexpressed genes compared with animal
E-mail: [email protected].
REFERENCES 1. Blaese RM, Culver KW, Miller AD, et al. T lymphocyte-directed gene therapy for ADA-
7. Olofsson B, Pajusola K, Kaipainen A, et al. Vascular endothelial growth factor B, a novel
SCID: initial trial results after 4 years. Science 1995;270:475–80.
growth factor for endothelial cells. Proc Natl Acad Sci U S A 1996;93:2576–81.
2. Lyon AR, Sato M, Hajjar RJ, Samulski RJ, Harding SE. Gene therapy: targeting the myocar-
8. Grimmond S, Lagercrantz J, Drinkwater C, et al. Cloning and characterization of a novel human
dium. Heart 2008;94:89–99.
gene related to vascular endothelial growth factor. Genome Res 1996;6:124–31.
14. Zhang F, Tang Z, Hou X, et al. VEGF-B is dispensable for blood vessel growth but critical for their survival, and VEGF-B targeting inhibits pathological angiogenesis. Proc Natl Acad Sci U S A 2009;106:6152–7.
9. Idriss NK, Blann AD, Lip GY. Hemoxygenase-1 in cardiovascular disease. J Am Coll Cardiol 2008;52: 971–8.
15. Zentilin L, Puligadda U, Lionetti V, et al. Cardiomyocyte VEGFR-1 activation by VEGF-B induces compensatory hypertrophy and preserves
3. Ishikawa K, Tilemann L, Ladage D, et al. Cardiac gene therapy in large animals: bridge from bench to bedside. Gene Ther 2012;19:670–7. 4. Hinkel R, Lange P, Petersen B, et al. Heme oxygenase-1 gene therapy provides cardioprotection via control of post-ischemic inflammation: an experimental study in a pre-clinical pig model. J Am Coll Cardiol 2015;66:154–65. 5. Tenhunen R, Marver HS, Schmid R. The enzymatic conversion of heme to bilirubin by microsomal heme oxygenase. Proc Natl Acad Sci U S A 1968;61:748–55. 6. Woitek F, Zentilin L, Hoffman NE, et al. Intracoronary cytoprotective gene therapy: a study of VEGF-B167 in a pre-clinical animal model of dilated cardiomyopathy. J Am Coll Cardiol 2015;66:139–53.
10. Wu ML, Ho YC, Yet SF. A central role of heme oxygenase-1 in cardiovascular protection. Antioxid Redox Signal 2011;15:1835–46. 11. Liu X, Simpson JA, Brunt KR, et al. Preemptive heme oxygenase-1 gene delivery reveals reduced mortality and preservation of left ventricular function 1 yr after acute myocardial infarction. Am J Physiol Heart Circ Physiol 2007; 293:H48–59. 12. Liu X, Pachori AS, Ward CA, et al. Heme oxygenase-1 (HO-1) inhibits postmyocardial infarct remodeling and restores ventricular function. FASEB J 2006;20:207–16.
13. Bry M, Kivela R, Leppanen VM, Alitalo K. Vascular endothelial growth factor-B in physiology and disease. Physiol Rev 2014;94:779–94.
cardiac function after myocardial FASEB J 2010;24:1467–78.
infarction.
16. Pepe M, Mamdani M, Zentilin L, et al. Intramyocardial VEGF-B167 gene delivery delays the progression towards congestive failure in dogs with pacing-induced dilated cardiomyopathy. Circ Res 2010;106:1893–903. 17. Hajjar R. Potential of gene therapy as a treatment for heart failure. J Clin Invest 2013;123:53–61.
KEY WORDS adeno-associated vectors, angiogenesis, apoptosis, gene therapy, heart failure, ischemia
VOL. 66, NO. 2, 2015 ISSN 0735-1097/$36.00 http://dx.doi.org/10.1016/j.jacc.2015.04.065
EDITORIAL COMMENT
Revisiting Old Players in the Revitalized Field of Cardiovascular Gene Therapy* Kiyotake Ishikawa, MD, Roger J. Hajjar, MD
S
ince its inception (1), clinical gene therapy has
actions have been well characterized in the cardio-
progressed substantially albeit slowly. The
vascular system. Heme oxygenase (HO)-1, a target
recent development of adeno-associated virus
protein in Hinkel et al. (4), was first identified in
(AAV) vectors has galvanized the field of gene therapy.
1968 (5), and this factor has been under continuous
These vectors have important characteristics that
investigation ever since in many organs throughout
make them safe and efficacious in various disease
the body. On the other hand, vascular endothelial
states. AAV vectors induce long-term and efficient
growth factor (VEGF)-B, evaluated in Woitek et al.
in vivo gene transduction in various organs, they do
(6), was first reported in 1996 (7,8), nearly 10 years
not produce a strong immune response, and they do
after the discovery of VEGF. This factor attracted
not integrate in the host DNA. Their ability to trans-
relatively little attention during the following years
duce the quiescent cells offers significant advantages
and its function remained incompletely defined.
over other gene therapy vectors for treating various
Recent advances in gene manipulation techniques
diseases (2). The recent success of clinical trials for
and genetic analysis revealed detailed information
Leber congenital amaurosis and hemophilia using re-
on the roles of these proteins in the heart. It seems
combinant AAV vectors has led to an increase in clin-
both HO-1 and VEGF-B have cardioprotective effects
ical translation of AAV-based gene therapy, including
and accordingly, a gene overexpression approach
in cardiovascular diseases. Another important feature
was tested in large animal models of cardiac
of AAV vectors is that there are several serotypes with
diseases using a cardiotropic AAV serotype 9.
each serotype having tropism to specific organs. Many
Hinkel et al. (4) focused on the anti-inflammatory
researchers are now consistently reporting efficacy of
profile of HO-1, evaluating the efficacy of HO-1 over-
AAV-mediated cardiac gene therapy in clinically rele-
expression in the setting of ischemia-reperfusion
vant animal models using their own gene targets and
injury. Although several drugs are reported to
delivery methods (3).
induce HO-1 activation and alleviate reperfusion
SEE PAGES 139 AND 154
injury (9), gene therapy holds an advantage of activating HO-1 specifically and, potentially, more effec-
In this issue of the Journal, 2 studies used gene
tively. In line with previous studies reporting the
transfer approaches to overexpress proteins whose
beneficial effects of HO-1 in protecting the heart from cardiac ischemia (10), the authors demonstrated the efficacy of AAV-mediated HO-1 overexpression for the first time in large animals. The study reports a sig-
*Editorials published in the Journal of the American College of Cardiology reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology. From the Cardiovascular Research Center, Icahn School of Medicine at
nificant reduction in infarct volume in HO-1 overexpressed pigs along with preserved left ventricular ejection fraction after 60 min of balloon-induced
Mount Sinai, New York, New York. This work is supported by the
ischemia followed by reperfusion. Although the
National Institutes of Health (NIH) (R01 HL117505 and HL119046), the
authors only examined the animals 24 h after the
National Heart, Lung, Blood Institute Program of Excellence in Nano-
ischemia-reperfusion injury, HO-1 has been shown to
technology Award (Contract HHSN268201000045C), NIH a P50 HL112324, and a Transatlantic Fondation Leducq grant. Both authors have reported
be protective even with permanent coronary occlu-
that they have no relationships relevant to the contents of this paper to
sion (11) and also inhibits cardiac remodeling at the
disclose.
chronic stages (12). Thus, a longer-term follow-up
Ishikawa and Hajjar
JACC VOL. 66, NO. 2, 2015 JULY 14, 2015:166–8
Revisiting Old Players in CV Gene Therapy
may have shown further benefit in the setting of
The authors modified the AAV delivery method to a
AAV’s long-term gene transduction.
more clinically practical intracoronary injection and
In the second study, Woitek et al. (6) focus on an
also tested this approach in dogs that were already
isoform of VEGF with a distinctive profile among its
developing heart failure. Strikingly, VEGF-B 167 gene
family. VEGF-B expression is highest in the heart
transfer at the middle of the pacing protocol ex-
and has only weak angiogenic effects in contrast to
hibited substantial preservation of left ventricular
other VEGFs (13). This protein seems to be a critical
ejection fraction and lowered end-diastolic pressure
prosurvival factor for vascular cells (14) and has
in the dogs receiving AAV9.VEGF-B 167. Although
similar protective effects on cardiomyocytes (15).
these results in a canine model of tachycardia-
AAV-mediated mouse VEGF-B 167 gene transfer pre-
induced heart failure are encouraging, this is a
served cardiac function and prevented the elevation
model with relatively acute disease progression that
of left ventricular end-diastolic pressure in a dog
decompensates within 28 days. For future clinical
model of tachy-pacing induced heart failure (6).
applications, further studies are necessary to vali-
Their work was an extension of a previous study by
date this therapy in more chronic models, using
the same group using a similar animal model (16).
human VEGF-B 167.
F I G U R E 1 Cardiac Gene Therapy Approaches Using AAV
Depending on the genes of interest, targeted phases of diseases differ. Conventional gene therapy mostly focuses on correcting the developed disease by gene transfer of down-regulated proteins, whereas the preventive approach is taken in the studies by Hinkel et al. (4) and Woitek et al. (6) in this issue of the Journal. AAV ¼ adeno-associated virus; HO-1 ¼ heme oxygenase-1; I-1c ¼ active form of protein phosphatase inhibitor 1; S100A1 ¼ calcium binding protein; SERCA2a ¼ cardiac sarcoplasmic reticulum Ca2þ ATPase pump; VEGF ¼ vascular endothelial growth factor.
167
168
Ishikawa and Hajjar
JACC VOL. 66, NO. 2, 2015 JULY 14, 2015:166–8
Revisiting Old Players in CV Gene Therapy
The 2 studies are inherently different from con-
studies. One very interesting approach used by Woitek
ventional cardiac gene therapy approaches that aim
et al. (6) is the disease-induced gene overexpression
to correct down-regulated/up-regulated genes in
using an atrial natriuretic factor promoter. Inducible
already developed diseases (Figure 1). Corrective
transgene regulation is extremely attractive because
therapies have included gene transfer of calcium
the gene expression can be controlled depending on
cycling protein including the cardiac sarcoplasmic
the disease activity, and can also be specific to the
reticulum Ca2þ ATPase pump (SERCA2a), the calcium
target organs. The atrial natriuretic factor promoter
binding protein S100A1, and the active form of pro-
would therefore turn on when the cardiac myocyte is in
tein phosphatase inhibitor 1 (I-1c) (17). Preventive
distress and be turned off when the myocyte is healthy.
therapies require treatment before disease progres-
A current limitation may be the lower transduction
sion because of the nature of the targeted genes. Both
efficacy as the authors reported, requiring a large
HO-1 and VEGF-B167 were effective at halting pro-
amount of vectors that might induce a T-cell response
gression of disease when administered before or at
in some of the patients.
the time of injury. Although disease prevention is
Despite the remaining issues that need to be solved
generally more efficient and effective compared with
before clinical translation occurs, therapeutic effi-
disease reversal, with current technology, it is very
cacies demonstrated in these 2 gene transfer studies
difficult to accurately predict whether or not an in-
using large animal models show that AAV-mediated
dividual patient will deteriorate. Advances in patient
cardiac gene therapy is maturing for clinical applica-
screening methods to identify high-risk profiles, such
tions. Advances in vector technology and gene de-
as genetic screening or induced-pluripotent stem
livery methods offer overexpression of not only novel
cell–mediated screening, may increase the value of
molecular targets but also well-known targets. It may
these preventive gene therapies.
be time to look back at some of the therapeutic targets
Unlike targeting genes already down-regulated
with “obsolete” labels.
in the disease setting, preventive gene therapy renders up-regulation of genes that are not usually
REPRINT REQUESTS AND CORRESPONDENCE: Dr.
activated in the normal setting. This may lead to un-
Roger J. Hajjar, Cardiovascular Research Center,
expected results in humans where complex molecular
Mount Sinai School of Medicine, One Gustave L. Levy
interactions are present and potentially longer expo-
Place, Box 1030, New York, New York 10029-6574.
sure to the overexpressed genes compared with animal
E-mail: [email protected].
REFERENCES 1. Blaese RM, Culver KW, Miller AD, et al. T lymphocyte-directed gene therapy for ADA-
7. Olofsson B, Pajusola K, Kaipainen A, et al. Vascular endothelial growth factor B, a novel
SCID: initial trial results after 4 years. Science 1995;270:475–80.
growth factor for endothelial cells. Proc Natl Acad Sci U S A 1996;93:2576–81.
2. Lyon AR, Sato M, Hajjar RJ, Samulski RJ, Harding SE. Gene therapy: targeting the myocar-
8. Grimmond S, Lagercrantz J, Drinkwater C, et al. Cloning and characterization of a novel human
dium. Heart 2008;94:89–99.
gene related to vascular endothelial growth factor. Genome Res 1996;6:124–31.
14. Zhang F, Tang Z, Hou X, et al. VEGF-B is dispensable for blood vessel growth but critical for their survival, and VEGF-B targeting inhibits pathological angiogenesis. Proc Natl Acad Sci U S A 2009;106:6152–7.
9. Idriss NK, Blann AD, Lip GY. Hemoxygenase-1 in cardiovascular disease. J Am Coll Cardiol 2008;52: 971–8.
15. Zentilin L, Puligadda U, Lionetti V, et al. Cardiomyocyte VEGFR-1 activation by VEGF-B induces compensatory hypertrophy and preserves
3. Ishikawa K, Tilemann L, Ladage D, et al. Cardiac gene therapy in large animals: bridge from bench to bedside. Gene Ther 2012;19:670–7. 4. Hinkel R, Lange P, Petersen B, et al. Heme oxygenase-1 gene therapy provides cardioprotection via control of post-ischemic inflammation: an experimental study in a pre-clinical pig model. J Am Coll Cardiol 2015;66:154–65. 5. Tenhunen R, Marver HS, Schmid R. The enzymatic conversion of heme to bilirubin by microsomal heme oxygenase. Proc Natl Acad Sci U S A 1968;61:748–55. 6. Woitek F, Zentilin L, Hoffman NE, et al. Intracoronary cytoprotective gene therapy: a study of VEGF-B167 in a pre-clinical animal model of dilated cardiomyopathy. J Am Coll Cardiol 2015;66:139–53.
10. Wu ML, Ho YC, Yet SF. A central role of heme oxygenase-1 in cardiovascular protection. Antioxid Redox Signal 2011;15:1835–46. 11. Liu X, Simpson JA, Brunt KR, et al. Preemptive heme oxygenase-1 gene delivery reveals reduced mortality and preservation of left ventricular function 1 yr after acute myocardial infarction. Am J Physiol Heart Circ Physiol 2007; 293:H48–59. 12. Liu X, Pachori AS, Ward CA, et al. Heme oxygenase-1 (HO-1) inhibits postmyocardial infarct remodeling and restores ventricular function. FASEB J 2006;20:207–16.
13. Bry M, Kivela R, Leppanen VM, Alitalo K. Vascular endothelial growth factor-B in physiology and disease. Physiol Rev 2014;94:779–94.
cardiac function after myocardial FASEB J 2010;24:1467–78.
infarction.
16. Pepe M, Mamdani M, Zentilin L, et al. Intramyocardial VEGF-B167 gene delivery delays the progression towards congestive failure in dogs with pacing-induced dilated cardiomyopathy. Circ Res 2010;106:1893–903. 17. Hajjar R. Potential of gene therapy as a treatment for heart failure. J Clin Invest 2013;123:53–61.
KEY WORDS adeno-associated vectors, angiogenesis, apoptosis, gene therapy, heart failure, ischemia