Designing Heart Performance by Gene Transfer (original) (raw)
Related papers
Modulation of Ventricular Function through Gene Transfer in vivo
Proceedings of The National Academy of Sciences, 1998
We used a catheter-based technique to achieve generalized cardiac gene transfer in vivo and to alter cardiac function by overexpressing phospholamban (PL) which regulates the activity of the sarcoplasmic reticulum Ca 2؉ ATPase (SERCA2a). By using this approach, rat hearts were transduced in vivo with 5 ؋ 10 9 pfu of recombinant adenoviral vectors carrying cDNA for either PL, -galactosidase (-gal), or modified green f luorescent protein (EGFP). Western blot analysis of ventricles obtained from rats transduced by Ad.PL showed a 2.8-fold increase in PL compared with hearts transduced by Ad.gal. Two days after infection, rat hearts transduced with Ad.PL had lower peak left ventricular pressure (58.3 ؎ 12.9 mmHg, n ؍ 8) compared with uninfected hearts (92.5 ؎ 3.5 mmHg, n ؍ 6) or hearts infected with Ad.gal (92.6 ؎ 5.9 mmHg, n ؍ 6). Both peak rate of pressure rise and pressure fall (؉3, 210 ؎ 298 mmHg͞s, ؊2, 117 ؎ 178 mmHg͞s, n ؍ 8) were decreased in hearts overexpressing PL compared with uninfected hearts (؉5, 225 ؎ 136 mmHg͞s, ؊3, 805 ؎ 97 mmHg͞s, n ؍ 6) or hearts infected with Ad.gal (؉5, 108 ؎ 167 mmHg͞s, ؊3, 765 ؎ 121 mmHg͞s, n ؍ 6). The time constant of left ventricular relaxation increased significantly in hearts overexpressing PL (33.4 ؎ 3.2 ms, n ؍ 8) compared with uninfected hearts (18.5 ؎ 1.0 ms, n ؍ 6) or hearts infected with Ad.gal (20.8 ؎ 2.1 ms, n ؍ 6). These differences in ventricular function were maintained 7 days after infection. These studies open the prospect of using somatic gene transfer to modulate overall cardiac function in vivo for either experimental or therapeutic applications.
Gene Transfer And Models Of Gene Therapy For The Myocardium
Clinical and Experimental Pharmacology and Physiology, 1999
1. Gene transfer into the myocardium can be achieved through direct injection of plasmid DNA or through the delivery of viral vectors, either directly or through the coronary vasculature. Direct DNA injection has proven extremely valuable in studies aimed at characterizing the activities of promoter elements in cardiac tissue and for examining the influence of the pathophysiological state of the myocardium on expression of transferred foreign genes.
American Journal of Physiology-heart and Circulatory Physiology, 2007
The aim of this study was to examine how global cardiac gene transfer of sarcoplasmic reticulum Ca 2+ -ATPase (SERCA2a) can influence left ventricular (LV) mechanical and energetic function, especially in terms of O2 cost of LV contractility, in normal rats. Normal rats were randomized to receive an adenovirus carrying either SERCA2a (SERCA) or -galactosidase ( gal) gene, or saline (Saline) by a catheter-based technique. LV mechanical and energetic function was measured in cross-circulated heart preparations 2-3 days after the infection. "SERCA" group showed the upward-shifted end-systolic pressure-volume relation, higher end-systolic pressure at 0.1 ml of intraballoon water volume and higher equivalent maximal elastance, i.e., the enhanced LV contractility, compared with "Normal", " gal" and "Saline" groups. Moreover, faster LV relaxation rate was found in "SERCA" group. There was no significant difference in relation between myocardial O2 consumption and systolic pressure-volume area among all groups. Finally, O2 cost of LV contractility in "SERCA" group was decreased to subnormal levels, but in " gal" and "Saline" groups it remained unchanged. This lowered O2 cost of LV contractility in "SERCA" hearts indicates energy saving in Ca 2+ handling during E-C coupling. Thus, the overexpression of SERCA2a was capable of transforming the normal energy utilization into a more efficient state in Ca 2+ handling, and super-inducing the supranormal contraction/relaxation due to the enhanced Ca 2+ handling.
Basic Research in Cardiology, 2001
The purpose was to determine the relative efficiency, toxicity and duration of expression following gene delivery by intramyocardial injection of naked DNA, naked DNA complexed to cationic liposomes, naked DNA complexed to cationic liposomes with integrin-targetting peptide, recombinant (E1-/E3-) adenovirus, recombinant adeno-associated virus and recombinant (ICP27-) herpes simplex virus. All vectors incorporated a LacZ reporter driven by a promoter containing the hCMV-IE promoter/enhancer. Efficiency was scored by counting positive cells in five standard microscopic sections harvested from the left ventricular apex. Rabbit hearts (n = 100) were examined from 2 to 56 days after injection. Uncomplexed and complexed naked DNA were very inefficient with less than one positive cell visible per heart. The viral vectors all resulted in robust gene expression with adenovirus being the most efficient by at least one order of magnitude before 21 days. However, despite disparate titres, the efficiency beyond 21 days of adenovirus and adeno-associated virus were comparable. In contrast to adeno-associated virus, both adenovirus and herpes-simplex virus were associated with a marked inflammatory response. Despite reporter gene activity appearing only after 21 days, adeno-associated virus shows comparative promise as a myocardial gene delivery vector. ˾ Key words Myocardial gene delivery-adenovirus-adeno-associated virus-herpes simplex virus-integrin targetting peptides BRC 263
Rescuing the Failing Heart by Targeted Gene Transfer
Journal of the American College of Cardiology, 2011
Congestive heart failure is a major cause of morbidity and mortality in the US. While progress in conventional treatments is making steady and incremental gains to reduce heart failure mortality, there is a critical need to explore new therapeutic approaches. Gene therapy was initially applied in the clinical setting for inherited monogenic disorders. It is now apparent that gene therapy has broader potential that also includes acquired polygenic diseases, such as congestive heart failure. Recent advances in understanding of the molecular basis of myocardial dysfunction, together with the evolution of increasingly efficient gene transfer technology, has placed heart failure within reach of gene-based therapy. Furthermore, the recent successful and safe completion of a phase 2 trial targeting the sarcoplasmic reticulum calcium ATPase pump (SERCA2a) along with the start of more recent phase 1 trials usher a new era for gene therapy for the treatment of heart failure.
Cardiovascular Research, 2006
Objective: Vectors based on recombinant adeno-associated virus 2 (AAV-2) are a promising tool for cardiac gene transfer. However, potential therapeutic applications need to consider the predominant transduction of the liver once AAV-2 vectors enter the systemic circulation. We therefore aimed to increase efficiency and specificity of cardiac vector delivery by combining transcriptional and cell surface targeting. Methods: For analysis of transcriptional targeting, recombinant AAV vectors were generated harboring a luciferase reporter gene under control of the cytomegalovirus (CMV) promoter or the 1.5-kb cardiac myosin light chain promoter fused to the CMV immediate-early enhancer (CMV enh /MLC1.5). Luciferase activities were determined in representative organs three weeks after intravenous injection of the vector into adult mice. Transductional targeting was studied using luciferase-reporter constructs crosspackaged into capsids of AAV serotypes 1 to 6 and modified AAV-2 capsids devoid of binding their primary receptor heparan sulfate proteoglycan. Results: Intravenous injections of AAV-2 vectors harboring the CMV enh /MLC1.5 promoter enabled a specific and 50-fold higher reporter gene expression in left ventricular myocardium of adult mice compared to vectors containing the CMV promoter. Comparison of AAV-2 vector genomes crosspackaged into capsids of AAV-1 to-6 showed that AAV-1,-4,-5, and-6 capsids increased cardiac transduction efficiency by about 10-fold. However, transduction of other organs such as the liver was also increased after systemic administration. In contrast, AAV-2-based vectors with ablated binding to their primary receptor heparan sulfate proteoglycan enabled a significantly increased efficiency of cardiac gene transfer and reduced transduction of the liver. Conclusions: Combining transcriptional targeting by the CMV enh /MLC1.5 promoter and AAV vectors devoid of binding the AAV-2 primary receptor results in an efficient cardiac gene transfer with a significantly reduced hepatic transduction.
Recent developments in gene therapy for cardiac disease
Biomedicine & Pharmacotherapy, 2000
-Cardiovascular[TRACE;del] disease is the leading cause of death in the US and worldwide. Advances in molecular biology and the human genome project have revealed opportunities for novel strategies for cardiac gene therapy. This review discusses general and specific aspects of gene transfer strategies in cardiac tissues. These include 1) the selection and/or optimization of the vector for gene transfer; 2) the identification of the target gene(s); 3) the use of cardiac-specific promoters; and 4) the use of an appropriate delivery system for administration. Currently, several vectors (e.g., viral and nonviral vectors) have been developed and many target genes have been identified (e.g., VEGF, FGF,-AR, etc.). Many investigations have provided experimental models for gene delivery systems but the most efficient cardiac gene transfer was obtained from intramyocardial injection or perfusion of explanted myocardium. The data available thus far have suggested favorable immediate effects following gene transfer, but long-term value of cardiac gene therapy has not been proven. Further refinements in appropriate vectors that provide cell or tissue selectivity and long-lasting effects are necessary as well as the development of minimally invasive procedures for gene transfer. © 2000 Éditions scientifiques et médicales Elsevier SAS adrenergic receptors / cardiovascular disease / gene therapy / gene transfer / growth factors / vectors *Correspondence and reprints.
One year transgene expression with adeno-associated virus cardiac gene transfer
International Journal of Cardiology, 2005
Background: Adeno-associated virus (AAV) has shown promise as a vector for cardiac gene transfer given its ability to stably integrate into the host genome and its lack of immune reactivity. This study examined the feasibility of AAV-mediated myocardial gene transfer in mice, the animal which, because of transgenic technology, has become the disease model of choice for cardiovascular research. Methods: AAV encoding the cytomegalovirus promoter driven LacZ reporter gene (10 7 LacZ-forming units per animal) or vehicle control was injected into the hearts of young adult C57Bl/6 mice by a transdiaphragmatic approach. At one, two, three, six, and twelve months postinjection, cardiac function was assessed by transthoracic echocardiography and hearts were assayed by X-gal histochemical staining. Results: Echocardiography revealed normal left ventricular function in both AAV and control groups at all time points. X-gal staining of cryostat sections of hearts revealed uniform LacZ expression at all time points. There were minimal signs of immunologic infiltration by hematoxylin and eosin staining. Conclusions: AAV-mediated myocardial gene transfer by transdiaphragmatic injection can be conducted safely and results in long-term expression of the LacZ gene for at least one year without causing significant inflammatory response or adversely affecting LV systolic function.
Targeted high-efficiency, homogeneous myocardial gene transfer
Journal of Molecular and Cellular Cardiology, 2007
Objective-Myocardial gene therapy continues to show promise as a tool for investigation and treatment of cardiac disease. Progress toward clinical approval has been slowed by limited in vivo delivery methods. We investigated the problem in a porcine model, with an objective of developing a method for high efficiency, homogeneous myocardial gene transfer that could be used in large mammals, and ultimately in humans. Methods-Eighty-one piglets underwent coronary catheterization for delivery of viral vectors into the left anterior descending artery and/or the great cardiac vein. The animals were followed for 5 or 28 days, and then transgene efficiency was quantified from histological samples. Results-The baseline protocol included treatment with VEGF, nitroglycerin, and adenosine followed by adenovirus infusion into the LAD. Gene transfer efficiency varied with choice of viral vector, with use of VEGF, adenosine, or nitroglycerin, and with calcium concentration. The best results were obtained by manipulation of physical parameters. Simultaneous infusion of adenovirus through both left anterior descending artery and great cardiac vein resulted in gene transfer to 78 ± 6% of myocytes in a larger target area. This method was well tolerated by the animals. Conclusions-We demonstrate targeted, homogeneous, high efficiency gene transfer using a method that should be transferable for eventual human usage.
Transplantation of genetically marked cardiac muscle cells
The Journal of Thoracic and Cardiovascular Surgery, 1997
We examined the possibility that cardiomyocytes could be genetically marked or modified before being grafted to the heart under conditions applicable to the clinical setting. We used a replication-defective recombinant adenovirus carrying the lB-galactosidase reporter gene, and delivered it to cultured murine fetal cardiac myocytes. Virtually all fetal cardiomyocytes in a primary culture expressed lB-galactosidase 24 hours after recombinant adenovirus infection. These cells were transplanted to t h e hearts of syngenic adult recipient mice. Expression of the/3-galactosidase gene in the grafted cells was demonstrated by staining with 5-bromo-4chloro-3-indoyl-lB-D-galactosidase, resulting in a blue color at the histochemical level and an electron-dense deposit on transmission electron microscopic analysis. Gene expression was recognized from 7 days to 12 weeks after transplantation. Implanted cardiomyocytes aligned themselves along the layers of the host myocardium. Formation of gap junctions was demonstrated by transmission electron microscopy. Neither inflammation nor fibrous scar tissue was detectable by histologic analysis. This study demonstrates that ex vivo gene transfer to the heart by means of the adenoviral vector is possible.