|
| HOME | SUBSCRIPTIONS | CURRENT ISSUE | PAST ISSUES | CARDIOSOURCE | SEARCH | HELP | FEEDBACK |
|
|
|
|||||||||
|
|||||||||||
|
J Am Coll Cardiol, 2000; 35:1323-1330 © 2000 by the American College of Cardiology Foundation |
* Heart Institute Research, Good Samaritan Hospital, Los Angeles, California, USA
Division of Cardiology, University of Southern California, Los Angeles, California, USA
Division of Cardiovascular Research, St. Elisabeth’s Medical Center and Tufts University School of Medicine, Boston, Massachusetts, USA
Department of Biochemistry and Molecular Biology, Department of Medicine, University of Southern California, Los Angeles, California, USA
Manuscript received February 4, 1999; revised manuscript received November 5, 1999, accepted December 15, 1999.
Reprint requests and correspondence: Dr. Robert A. Kloner, Heart Institute, Good Samaritan Hospital & Division of Cardiology, University of Southern California, 1225 Wilshire Boulevard, Los Angeles, California 90017-2395
RKloner{at}goodsam.org
 |
Abstract |
|---|
 Top Abstract MethodsResultsDiscussionReferences |
|---|
The effects of direct intramyocardial injection of the plasmid encoding vascular endothelial growth factor (phVEGF165) in the border zone of myocardial infarct tissue in rat hearts were investigated.
BACKGROUND
Controversy exists concerning the ability of VEGF to induce angiogenesis and enhance coronary flow in the myocardium.
METHODS
Sprague-Dawley rats received a ligation of the left coronary artery to induce myocardial infarction (MI). At 33.1 ± 6.5 days, the rats were injected with phVEGF165 at one location and control plasmid at a second location (500 µg DNA, n = 24) or saline (n = 16). After 33.1 ± 5.7 days, the hearts were excised for macroscopic and histologic analysis. Regional blood flow ratios were measured in 18 rats by radioactive microspheres.
RESULTS
phVEGF165-treated sites showed macroscopic angioma-like structures at the injection site while control DNA and saline injection sites did not. By histology, 21/24 phVEGF165-treated hearts showed increased focal epicardial blood vessel density and angioma-like formation. Quantitative morphometric evaluation in 20 phVEGF165-treated hearts revealed 44.4 ± 10.5 vascular structures per field in phVEGF165-treated hearts versus 21.4 ± 4.7 in control DNA injection sites (p < 0.05). Regional myocardial blood flow ratios between the injection site and noninfarcted area did not demonstrate any difference between phVEGF165-treated hearts (0.9 ± 0.2) and saline-treated hearts (0.7 ± 0.1).
CONCLUSIONS
Injection of DNA for VEGF in the border zone of MI in rat hearts induced angiogenesis. Angioma formation at the injection sites did not appear to contribute to regional myocardial blood flow, which may be a limitation of gene therapy for this application.
| ||||||||||||||
An elegant series of experiments defined striated muscle (16–19), including heart (20–22) as a tissue with the unique property of being able to take up and express recombinant proteins after local injection of DNA. Such direct injection technology is capable of delivering exogenous genes into myocardium fully governed by hormone inducible, tissue specific or strong viral promoters (23–25). We hypothesized that ischemic myocardium would be capable of taking up and expressing VEGF delivered by plasmid DNA injections. So far, the effects of VEGF in infarcted tissue in the rat heart have not been investigated. We hypothesized that application of VEGF encoding DNA directly to the healing infarct might augment angiogenesis and increase blood flow in infarcted rat heart. Potential benefits would include enhancing blood flow to a healing infarct, possibly accelerating healing, preventing remodeling and allowing open vessels to provide drugs to the area of scar. In addition, clinical trials are currently underway assessing the effect of this type of gene therapy in patients with chronic ischemia. Whether injection of the gene for VEGF into tissue recently infarcted is safe is not yet known.
|
Methods |
|---|
|
TopAbstractMethodsResultsDiscussionReferences |
|---|
DNA was extracted from the cultures with Qiagen Plasmid Giga Kit. Three L of culture usually provided 10 to 12 mg of plasmid DNA. All experiments were conducted in accordance with institutional guidelines and The Guide for the Care and Use of Laboratory Animals published by the National Research Council, Washington DC, 1996.
Sprague-Dawley rats, weighing between 200 and 350 g, were used (Charles River, Inc., Wilmington, Massachusetts). Each rat underwent:
Apart from the final procedure, all surgeries were performed under aseptic conditions. The rats were anesthetized with ketamine (75 mg/kg) and xylazine (5 mg/kg), intraperitoneally. They were intubated and artificially respirated with a rodent respirator (Harvard) with 15 to 20 ml/kg room air at a respiration rate of 75 breaths/min.
Coronary artery occlusion. The chest was opened in the fourth intercostal space. The pericardium was opened, and a 6.0 prolene suture was placed around the base of the left coronary artery near the left atrial appendage. Coronary occlusion was confirmed by the presence of deep S waves on the electrocardiogram (ECG) and ventricular arrhythmias within the first 20 to 30 min after occlusion. Thereafter, the chest and the skin were closed in layers, and the animals were allowed to recover.
Injection of phVEGF165 or saline. At 33.1 ± 6.5 days after coronary artery occlusion, the animals were used for either a treated (phVEGF165) group or a control (saline) group in random order (except the first five animals, which all received phVEGF165). The feasibility of gene transfer in the rat model has been described before by our group (25–27). This time interval after coronary occlusion was chosen to avoid injection into necrotic debris but chosen to inject into partially healed infarcts. After opening the chest and identifying the infarcted area in the anterolateral wall, two 6.0 prolene sutures were placed at the border zones of the infarcted tissue: one anteriorly and one laterally. These areas were chosen for two reasons: 1) to introduce plasmid DNA into a "watershed" area in terms of blood supply, and 2) to augment the effects of locally expressed VEGF from cells bordering the necrotic area (19,20). The sutures were used to stabilize the myocardium for injection and to close the injection hole so that the agents would not leak out. In the treated group, 500 µg of phVEGF165 plasmid DNA in a volume of 0.15 ml was injected intramyocardially at the left anterior border zone of the visible scar tissue in the left anterior free wall by use of a 0.5 ml syringe and a 24G needle. In the same rats, control DNA (500 µg, 0.15 ml) of the reporter gene pCMVbeta (7.2 Kb), a plasmid capable of expressing the E. coli beta-galactosidase gene under the control of human cytomegalovirus (CMV) immediate early promoter/enhancer was injected into the left lateral border zone of the scar tissue. Thirty-six animals were used for the phVEGF165 group, and 19 animals were used for saline-treated controls (that is, without DNA injection). In a subgroup of eight animals, the injection sites for phVEGF165 and pCMVbeta were changed to the lateral and anterior infarct border zones, respectively. In control animals, 0.15 ml saline was injected at both sites. Care was taken to inject the substances within the epicardial layer of the scar, and this was confirmed by the presence of a ‘bubble’ in the epicardium as the syringe was unloaded. In two animals (one from each group), the sutures were removed a few minutes after injection to assess the effects of the suture material. Thereafter, the chest was closed and the animals were allowed to recover.
Expression of VEGF. To ensure that the phVEGF165 plasmid expresses VEGF, an in vitro analysis using mammalian cells was performed. Therefore, 293 and cos 7 cells were transfected with plasmid DNA using the calcium phosphate precipitation method. After 72 hours, the media was harvested and washed cells lysed. The media was concentrated ten-fold with 75% ammonium sulfate. Aliquots of boiled media and lysate were separated by denaturing polyacrylamide gel electrophoresis and examined by Western blotting with A-20, an anti-VEGF antibody (Santa Cruz Biotechnology) and antirabbit IgG (Amersham, Sunnyvale, California). Furthermore, VEGF protein and aliquots of media and cell lysate from cells transfected with the plasmid vector backbone were examined.
Radioactive microsphere injection and excision of the hearts. 33.1 ± 5.7 days after injection, all animals were reanesthetized, and the chest was opened. In a subgroup of 18 animals, radioactive microspheres (NEN Research Products, Boston, Massachusetts), approximately 100,000 in number, labeled with 141Ce, were injected into the left ventricular cavity. The microspheres were allowed to circulate for one min. Thereafter, the animals were euthanized, and the hearts were excised. Tissue specimens from the anterior and the lateral injection sites within the infarcted border zone and from the septum were excised for measurements of radioactivity. All infarcts were fairly large, and they were composed of mainly fibroblasts and collagen. The activities in the VEGF-injected and the saline-injected regions were expressed per weight of heart tissue as a ratio relative to the activity in the septum and the control infarcted tissue.
Morphologic analysis. After excision of the hearts at 33.1 ± 5.7 days after injection, the injection sites were identified and examined grossly in all hearts. Short axis slices were made from apex to base. In hearts that did not receive microspheres, the transmural slices were then processed for histology. In hearts used for radioactive microsphere injection, hearts were dissected, and the samples used for radioactivity measurements were examined for later histologic analysis. The slices were processed for hematoxylin-eosin (n = 39) and smooth muscle alpha-actin antibody staining (n = 20), as previously reported (28).
In addition, tissues from four VEGF-treated hearts and one control heart were incubated with antihuman antibody to VEGF (R&D Systems, Minneapolis, Minnesota) at a concentration of 50 µg/ml for 20 min at 37°C, in humidity chambers. After rinsing in PBS, the tissues were incubated in horse radish peroxidase–tagged labeling reagent (BioGenex, San Ramon, California) for an additional 20 min at 37°C. The specimens were rinsed in PBS and reacted with metal enhanced diaminobenzidine (Sigma) for 2 to 5 min at room temperature, with periodic monitoring by microscopic examination. After development, the samples were rinsed and stained with either hematoxylin and eosin or nuclear fast red and metanil yellow. Sections were dehydrated through xylene and mounted with permount.
In a subgroup of 30 animals, a morphometric analysis of blood vessels was conducted. The hematoxylin and eosin (H + E) slides were examined and marked by one investigator on each side of the infarction. This corresponded to the injection sites of phVEGF165 or pCMVbeta or saline (or noninjection). The slides were then examined for evidence of vascular proliferation by another investigator unaware of the treatment groups. The tissue sections were projected through a 10x objective and a 4x projection lens to a 46 x 61 cm paper palate and the tissue perimeter and vascular structures identified, outlined and planimetered.
In a subgroup of animals, the epicardial and endocardial circumferences of the infarcted ventricle (scar) and the total left ventricle were measured by planimetry and expressed as the ratio of scar circumference to left ventricular circumference.
Statistical analysis. All values are given as means ± standard error of the mean (SEM). Comparisons between the groups or within the groups were made using paired or group t test, as appropriate. Data regarding histology of the angiomatous structures were tested by Fisher exact test. P values <0.05 were considered statistically significant.
|
Results |
|---|
|
TopAbstractMethodsResultsDiscussionReferences |
|---|
Macroscopic evaluation (Figure 1, A and B). Macroscopic inspection of the hearts at the time of euthanasia typically revealed the presence of broad-based angioma-like formations at the site of phVEGF165 injection, whether injected anteriorly or laterally, but not at the site of pCMVbeta injection. The angioma-like structure was also found in the heart in which the suture material was removed after injection. In contrast, saline injected control hearts demonstrated small adhesions in some cases but no angioma-like structures.
|
Cross sections of H + E slices of phVEGF165-treated hearts containing these angioma-like structures showed them protruding from the surface of the scars often several mm. Within these structures most of the small vessels consisted only of simple endothelial cell tubes, but some vessels with smooth muscle cells in the media also were identified. Erythrocytes often could be visualized within the vessels. Lymphocytes were occasionally found in treated and control hearts at the injection sites and tended to be more prominent in hearts injected with phVEGF165. Both compact and loose fibrous tissue were also visualized in these structures as well as occasional fat cells. Figures 2 and 3 illustrate typical H + E examples for phVEGF165-treated and control hearts. Within the angiomatous structures, most vascular structures were negative for alpha-actin staining, again suggesting that they were primarily simple endothelial tubes without smooth muscle.
|
|
Morphometric analysis of vascular structures. Morphometric analysis was performed in 20 phVEGF165-treated hearts and in 10 saline-treated control hearts. In phVEGF165-treated hearts, the slices containing angioma-like structures were analyzed. In addition, in five phVEGF165-treated hearts, slices that did not contain the angioma-like structures were also analyzed. The number of vascular structures within the projected field was significantly higher in phVEGF165-injected sites at 44.4 ± 10.5 per field as compared with pCMVbeta-injected areas at 21.4 ± 4.7, p < 0.05, and significantly higher compared with the equivalent saline injection sites in control animals (21.1 ± 3.0, p < 0.05 vs. phVEGF165 injection site). There was a nonsignificant trend toward higher numbers of vascular structures in phVEGF165 injection sites if compared with all saline injection sites in control animals (30.1 ± 4.6). In contrast, in those slices not containing angioma-like structures in the phVEGF165-treated hearts, there were 12.6 ± 2.2 vascular structures (p < 0.05 vs. phVEGF165-treated slices with angioma-like structures [44.4 ± 10.5]). The percent of the area examined that contained vascular structures was greater within those left ventricular slices containing angioma-like structures in phVEGF165-treated animals (4.5 ± 1.3%) versus those slices in phVEGF165-treated animals that received control DNA (1.1 ± 0.1%, p < 0.05) versus equivalent control saline-treated areas (2.4 ± 0.6, p = 0.08) versus all saline injected areas (2.8 ± 0.6%).
Expression of VEGF. We insured that phVEGF165 was capable of producing VEGF polypeptide in mammalian cells. Bands at 21 kD corresponding to the reported size of phVEGF165 were present in both cell lysate and media of both 293 and cos 7 cells. To insure further that the bands were not due to interaction between VEGF and secondary antibody, primary antibody was neutralized by a blocking peptide (Santa Cruz Biotechnology, Santa Cruz, California) before incubation with the membrane. The 21 kD bands and the positive control band were no longer detected. Thus, mammalian cells carrying the phVEGF165 plasmid DNA we delivered to the myocardium was capable of synthesizing and secreting VEGF protein.
Measurement of infarct and left ventricular circumferences. Measurements of the epicardial and endocardial infarct scar and total circumferences of the left ventricle in 22 hearts (12 phVEGF165-treated hearts and 10 controls) revealed an epicardial scar/left ventricular circumference ratio of 0.26 ± 0.02 in phVEGF165-treated animals versus 0.32 ± 0.03 in controls (p = 0.09). The endocardial scar/left ventricular circumference ratio was 0.34 ± 0.04 in VEGF-treated hearts versus 0.40 ± 0.04 in controls (p = NS).
Measurements of regional blood flow. Radioactive microspheres were used to measure relative blood flow in 12 phVEGF165-treated hearts and in six saline-treated controls. The septum, which was noninfarcted in this model, served as the reference region. The pCMVbeta injection site served as the control infarct region in treated animals. The ratios between phVEGF165 injection site and pCMVbeta injection site in treated and between the two saline injection sites in control animals were used for group comparison. The ratio of counts of the injection site and in the septum between treated and control hearts were analyzed (Table 1). There were no significant differences in relative blood flow between the two groups.
|
|
Discussion |
|---|
|
TopAbstractMethodsResultsDiscussionReferences |
|---|
The development of angiomatous structures. The development of angioma-like structures was found only within the phVEGF165-injected areas and was independent of its location or the presence of a suture. The development of these angioma-like structures is probably analogous to the role of VEGF in tumor angiogenesis (29,30). The clinical significance of these angiomas over time remains unknown. They did not worsen infarct expansion, and, in fact, there was a nonsignificant trend to reduce scar circumference in phVEGF165-treated hearts.
It has been shown in dogs that infarcted or chronically ischemic myocardial tissue is more sensitive to the mitogenic effects of another growth factor—exogenous acidic fibroblast growth factor—because its epicardial application induced a tumor-like smooth muscle cell hyperplasia (31). In our study, tumor-like angioma occurred within infarcted tissue; this phenomenon might limit the clinical application of VEGF by plasmid DNA injection in the treatment of myocardial ischemia in human patients and suggests that such injection perhaps should be avoided in patients with recent infarcts. Of note, one patient who received the plasmid for VEGF in the peripheral arteries developed transient cutaneous angiomas (13). A recently published report of direct injection of phVEGF165 into human myocardium in five patients demonstrated a slight reduction of symptoms and improvement in myocardial perfusion (as assessed by nuclear imaging [32]). However, a macroscopic or histologic evaluation of the injection sites was not feasible, and a clinical follow-up is not yet available, but these patients had no recent myocardial infarction, which might play a role in the development of angiomatous structures.
The effects on myocardial perfusion. Relative, rather than absolute, blood flow measurements were performed in our model because of the difficulty of withdrawing reference blood samples in the rat. The phVEGF165 injection site/control area ratios did not show any significant difference compared with controls. Potential explanations for this include the possibility that the new blood vessels were simply too small to allow microsphere penetration, that the spheres may have shunted around the blood vessels in the angioma or that the possibility that flow within these angiomatous structures simply does not differ from flow in the control border zone—that is, these structures may not contribute to overall increase in regional myocardial blood flow.
A variety of studies have investigated the effects of VEGF to induce angiogenesis in peripheral arteries of animals (10–12,27,33,34) and, recently, humans (13,35–37), with some degree of success. Furthermore, in dogs subjected to chronic left circumflex artery stenosis, intracoronary administration of VEGF-peptide increased collateral blood flow (14). In contrast, in another study in dogs subjected to chronic left circumflex artery occlusion, VEGF-protein injected into the left atrial cavity had no effect on collateral flow or blood vessel development (while basic fibroblast growth factor did) (15). The differences between this and the other studies might be explained by the difference in the models, species, route of protein delivery or severity of the ischemic stimulus.
Preliminary results are available from intracoronary application of VEGF-protein in the human heart, which demonstrates improvement in myocardial perfusion as assessed by nuclear imaging (38). However, it remains to be seen whether application of VEGF has long-term beneficial effects in the heart. Notably, it has not been shown whether angiogenesis augments contractile function. In the setting of a healed myocardial infarction, if angiogenesis is induced, it may either improve perfusion of scar tissue or border zone tissue, or, alternatively, the gene and its effect may be distributed all over the heart ("A little VEGF goes a long way," [39]) with improvement in perfusion and salvage of jeopardized cells (40,41). The beneficial effects of VEGF-induced angiogenesis may be masked by the induction of vascular abnormalities, which have been described recently after intravitreous injection in monkeys (42). Furthermore, it has been shown that expression of VEGF is not only essential for embryonic angiogenesis but also can induce the formation of angioblasts, hemangioblasts and vascular and cardiovascular malformation (43,44). This is not surprising given the involvement of VEGF in tumorgenesis (29,30) and neonatal hemangiomas (45).
Study limitations. The exact reason that more rats died within 24 h in the VEGF group is unknown, but:
One explanation for our findings might be that a high transfection efficiency of gene expression caused angioma formation in our study. The present data confirm that injection of the plasmid causes expression of VEGF, and we demonstrated that labeling appeared most intense around the angioma, indicating an effect directly caused by VEGF plasmid injection. However, we used a dose of phVEGF165 identical to that used in rabbits before. The much smaller body weight of rats might have influenced the results. Therefore, in a recent study, smaller doses of phVEGF165 were used (125 µg), similar to doses used in clinical trials, and this did not result in gross angiomas in the rat model (48). These findings support, in part, a dose-dependence that previously has been reported after VEGF gene application in muscle tissue (49). In that study, Spinger et al. (49) reported that high levels of VEGF expression caused hemangiomas in adult skeletal muscles, whereas muscle exposed to low serum levels did not develop vascular malformations.
Conclusions. It seems that a potential therapeutic application of VEGF in a setting of myocardial ischemia or infarction is a double-edged sword: on one hand it has the ability to induce angiogenesis and enhance coronary flow (50), while on the other hand it may also induce vascular malformation. Whether the dose that was used here or the location, mode or time of VEGF injection or other factors play a role in the development of angiomas in our model has not yet been clarified. There is a need for further experimental studies using VEGF to identify the circumstances under which collateral flow can be enhanced without development of vascular malformations.
|
Footnotes |
|---|
|
References |
|---|
|
TopAbstractMethodsResultsDiscussionReferences |
|---|
This article has been cited by other articles:
|
|
 |
|
  C Kalka and I. Baumgartner Gene and stem cell therapy in peripheral arterial occlusive disease Vascular Medicine, May 1, 2008; 13(2): 157 - 172. [Abstract] [PDF]
|
|
|
|
 |
|
 K. A. Horvath and Y. Zhou Transmyocardial Laser Revascularization and Extravascular Angiogenetic Techniques to Increase Myocardial Blood Flow Card. Surg. Adult, January 1, 2008; 3(2008): 733 - 752. [Full Text]
|
|
|
|
 |
|
 E. K. Sim, L. Ye, and H. K. Haider New Strategy for Cardiac Repair: Genetically Modified Skeletal Myoblasts Asian Cardiovasc Thorac Ann, June 1, 2007; 15(3): 183 - 184. [Full Text] [PDF]
|
|
|
|
 |
|
 O. J. Muller, H. A. Katus, and R. Bekeredjian Targeting the heart with gene therapy-optimized gene delivery methods Cardiovasc Res, February 1, 2007; 73(3): 453 - 462. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. von Degenfeld, A. Banfi, M. L. Springer, R. A. Wagner, J. Jacobi, C. R. Ozawa, M. J. Merchant, J. P. Cooke, and H. M. Blau Microenvironmental VEGF distribution is critical for stable and functional vessel growth in ischemia FASEB J, December 1, 2006; 20(14): 2657 - 2659. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. J. Boyle, S. P. Schulman, and J. M. Hare Stem Cell Therapy for Cardiac Repair: Ready for the Next Step Circulation, July 25, 2006; 114(4): 339 - 352. [Full Text] [PDF]
|
|
|
|
 |
|
 H. Iwama, S. Uemura, N. Naya, K.-i. Imagawa, Y. Takemoto, O. Asai, K. Onoue, S. Okayama, S. Somekawa, Y. Kida, et al. Cardiac Expression of Placental Growth Factor Predicts the Improvement of Chronic Phase Left Ventricular Function in Patients With Acute Myocardial Infarction J. Am. Coll. Cardiol., April 18, 2006; 47(8): 1559 - 1567. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Heinl-Green, P. W. Radke, F. M. Munkonge, O. Frass, J. Zhu, K. Vincent, D. M. Geddes, and E. W.F.W. Alton The efficacy of a 'master switch gene' HIF-1{alpha} in a porcine model of chronic myocardial ischaemia Eur. Heart J., July 1, 2005; 26(13): 1327 - 1332. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Manenti, E. Riccardi, S. Marchini, E. Naumova, I. Floriani, A. Garofalo, R. Dossi, E. Marrazzo, D. Ribatti, E. Scanziani, et al. Circulating plasma vascular endothelial growth factor in mice bearing human ovarian carcinoma xenograft correlates with tumor progression and response to therapy Mol. Cancer Ther., May 1, 2005; 4(5): 715 - 725. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. A. Krombach, J. G. Pfeffer, S. Kinzel, M. Katoh, R. W. Gunther, and A. Buecker MR-guided Percutaneous Intramyocardial Injection with an MR-compatible Catheter: Feasibility and Changes in T1 Values after Injection of Extracellular Contrast Medium in Pigs Radiology, May 1, 2005; 235(2): 487 - 494. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Waltenberger Growth factor signal transduction defects in the cardiovascular system Cardiovasc Res, February 15, 2005; 65(3): 574 - 580. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. E. Markkanen, T. T. Rissanen, A. Kivela, and S. Yla-Herttuala Growth factor-induced therapeutic angiogenesis and arteriogenesis in the heart-gene therapy Cardiovasc Res, February 15, 2005; 65(3): 656 - 664. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Schuh, S. Breuer, R. Al Dashti, N. Sulemanjee, P. Hanrath, C. Weber, B. F. Uretsky, and E. R. Schwarz Administration of Vascular Endothelial Growth Factor Adjunctive to Fetal Cardiomyocyte Transplantation and Improvement of Cardiac Function in the Rat Model Journal of Cardiovascular Pharmacology and Therapeutics, January 1, 2005; 10(1): 55 - 66. [Abstract] [PDF]
|
|
|
|
 |
|
 T.-B. Liu, P. W. M. Fedak, R. D. Weisel, T. Yasuda, G. Kiani, D. A. G. Mickle, Z.-Q. Jia, and R.-K. Li Enhanced IGF-1 expression improves smooth muscle cell engraftment after cell transplantation Am J Physiol Heart Circ Physiol, December 1, 2004; 287(6): H2840 - H2849. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Su, S. Joho, Y. Huang, A. Barcena, J. Arakawa-Hoyt, W. Grossman, and Y. W. Kan Adeno-associated viral vector delivers cardiac-specific and hypoxia-inducible VEGF expression in ischemic mouse hearts PNAS, November 16, 2004; 101(46): 16280 - 16285. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. R. Schwarz, D. A. Meven, N. Z. Sulemanjee, P. H. Kersting, T. Tussing, E. C. Skobel, P. Hanrath, and B. F. Uretsky Monocyte Chemoattractant Protein 1-Induced Monocyte Infiltration Produces Angiogenesis but Not Arteriogenesis in Chronically Infarcted Myocardium Journal of Cardiovascular Pharmacology and Therapeutics, October 1, 2004; 9(4): 279 - 289. [Abstract] [PDF]
|
|
|
|
|
|
L. Lei, R. Zhou, W. Zheng, L. P. Christensen, R. M. Weiss, and R. J. Tomanek Bradycardia Induces Angiogenesis, Increases Coronary Reserve, and Preserves Function of the Postinfarcted Heart Circulation, August 17, 2004; 110(7): 796 - 802. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Sesti and R. A. Kloner Gene Therapy in Congestive Heart Failure Circulation, July 20, 2004; 110(3): 242 - 243. [Full Text] [PDF]
|
|
|
|
|
|
A. N. Carr, M. G. Davis, E. Eby-Wilkens, B. W. Howard, B. A. Towne, T. E. Dufresne, and K. G. Peters Tyrosine phosphatase inhibition augments collateral blood flow in a rat model of peripheral vascular disease Am J Physiol Heart Circ Physiol, July 1, 2004; 287(1): H268 - H276. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Ye, H. K Haider, S.-J. Jiang, and E. K. Sim Therapeutic Angiogenesis Using Vascular Endothelial Growth Factor Asian Cardiovasc Thorac Ann, June 1, 2004; 12(2): 173 - 181. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. L. Tang, Y. Tang, Y. C. Zhang, K. Qian, L. Shen, and M. I. Phillips Protection From Ischemic Heart Injury by a Vigilant Heme Oxygenase-1 Plasmid System Hypertension, April 1, 2004; 43(4): 746 - 751. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Bekeredjian, S. Chen, P. A. Frenkel, P. A. Grayburn, and R. V. Shohet Ultrasound-Targeted Microbubble Destruction Can Repeatedly Direct Highly Specific Plasmid Expression to the Heart Circulation, August 26, 2003; 108(8): 1022 - 1026. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Funatsu, Y. Sawa, S. Ohtake, T. Takahashi, G. Matsumiya, N. Matsuura, T. Nakamura, and H. Matsuda Therapeutic angiogenesis in the ischemic canine heart induced by myocardial injection of naked complementary DNA plasmid encoding hepatocyte growth factor J. Thorac. Cardiovasc. Surg., December 1, 2002; 124(6): 1099 - 1105. [Abstract] [Full Text]
|
