Chemistry: molecular biology and microbiology – Measuring or testing process involving enzymes or... – Involving antigen-antibody binding – specific binding protein...
Reexamination Certificate
2000-01-13
2001-04-24
Marschel, Ardin H. (Department: 1631)
Chemistry: molecular biology and microbiology
Measuring or testing process involving enzymes or...
Involving antigen-antibody binding, specific binding protein...
C435S375000, C435S377000
Reexamination Certificate
active
06221618
ABSTRACT:
TECHNICAL FIELD
This invention relates to compounds which affect ventricular muscle cell hypertrophy, an assay for identifying such compounds, and to methods for modulating cardiac function in the treatment of heart disorders.
BACKGROUND OF THE INVENTION
Heart failure affects approximately three million Americans, developing at a rate of approximately 400,000 new cases per year. Current therapy for heart failure is primarily directed to using angiotensin-converting enzyme (ACE) inhibitors and diuretics. ACE inhibitors appear to slow the progression towards end-stage heart failure in patients; however, they are unable to relieve symptoms in more than 60% of heart failure patients and reduce mortality of heart failure only by approximately 15-20%. Heart transplantation is limited by the availability of donor hearts. With the exception of digoxin, the chronic administration of positive inotropic agents has not resulted in a useful drug without accompanying adverse side effects, such as increased arrhythmia, sudden death, or other deleterious side effects related to survival. These deficiencies in current therapy suggest the need for additional therapeutic approaches.
Cardiac muscle hypertrophy is one of the most important adaptive physiological responses of the myocardium. In response to increased demands for cardiac work or following a variety of pathological stimuli which lead to cardiac injury, the heart adapts through the activation of a hypertrophic response in individual cardiac muscle cells, which is characterized by an increase in myocyte size, the accumulation of contractile proteins within individual cardiac cells, the activation of embryonic gene markers expression, and the lack of a concomitant effect on muscle cell proliferation. Although the hypertrophic process can initially be compensatory, there can be a pathological transition in which the myocardium becomes dysfunctional (Braunwald (1994) in
Pathophysiology of Heart Failure
, (Braunwald, ed.); Saunders, Philadelphia; Vol. 14, pp 393-402).
Studies in an in vitro model system of ventricular muscle cell hypertrophy have led to the identification of a number of mechanical, hormonal, growth factor, and pathological stimuli which can activate several independent features of hypertrophy (Chien et al. (1991) FASEB J. 5:3037-3046; Knowlton et al. (1991.) J. Biol. Chem. 266:7759-7768; Shubeita et al. (1990) J. Biol. Chem. 265:20555-20562; Thorburn et al. (1993) J. Biol. Chem. 268:2244-2249; LaMorte et al. (1994) J. Biol. Chem. 269:13490-13496; Knowlton et al. (1993) J. Biol. Chem. 268:15374-15380). Currently, there are at least two signal transduction pathways, involving both ras- (Thorburn et al. (1993) supra), and G
q
protein-dependent downstream effectors (LaMorte et al. (1994) supra) implicated in the activation of features of the hypertrophic response in the in vitro model system.
While progress has been made in uncovering the signaling pathways which activate the ventricular muscle cell hypertrophic response, relatively little is known as to mechanisms which inhibit or suppress the hypertrophic response.
There is a need for an improved heart failure therapy, such as congestive heart failure and hypertrophic cardiomyopathy.
SUMMARY OF THE INVENTION
The present invention is based in part on the discovery that retinoic acid suppresses &agr;
1
-adrenergic agonist- and endothelin-mediated ventricular muscle cell hypertrophy. Accordingly, the invention features a method of suppressing ventricular muscle cell-hypertrophy by contacting ventricular muscle cells with an effective amount of a retinoic acid compound, retinoic acid derivative, or pharmaceutical salt thereof.
The invention features a method of identifying compounds which suppress ventricular muscle cell hypertrophy, comprising contacting ventricular muscle cells with a test compound in the presence of an inducer of ventricular muscle cell hypertrophy, and measuring the development of ventricular muscle cell hypertrophy.
The development of hypertrophy in ventricular muscle cells is measured in cells exposed to an inducer of ventricular muscle cell hypertrophy with and without the test compound, and the development of hypertrophy compared. The development of ventricular muscle cell hypertrophy is measured in a variety of ways, including by increase in cell size, induction of a genetic marker of ventricular muscle cell hypertrophy, increase in the assembly of an individual contractile protein such as myosin light chain-2v (MLC-2v) into organized contractile units, accumulation of contractile units, activation of a program of immediate early gene expression, and the induction of genes encoding contractile and embryonic proteins. In a specific embodiment, ventricular muscle cell hypertrophy is measured by determining the expression of an atrial marker, for example, atrial natriuretic factor (ANF).
In one embodiment of the method of identifying compounds which suppress ventricular muscle cell hypertrophy, cells are incubated with an inducer of &agr;
1
-adrenergic-mediated hypertrophy with and without the test compound, and the ability of the test compound to suppress development of &agr;
1
-adrenergic-mediated ventricular muscle cell hypertrophy measured. In another embodiment, the cells are incubated with an endothelin with and without the test compound, and the ability of the test compound to suppress endothelin-mediated ventricular muscle cell hypertrophy determined. A test compound which suppresses ventricular muscle cell hypertrophy may block a hypertrophic pathway in a variety of ways, including by activating retinoic acid-specific receptors, e.g., RAR.
The invention features a method for identifying compounds which inhibit retinoic acid suppression of ventricular muscle cell hypertrophy. A compound may inhibit retinoic acid suppression of ventricular muscle cell hypertrophy by blocking, suppressing, reversing, or antagonizing the action of the retinoic acid action. In one embodiment, cells are incubated with an inducer of ventricular muscle cell hypertrophy in the presence of a retinoic acid compound that suppresses the development of ventricular muscle cell hypertrophy, and with and without the test compound, and the ability of the test compound to block the retinoic acid compound suppression of ventricular muscle cell hypertrophy is measured. The inducer of ventricular muscle cell hypertrophy may be an &agr;
1
-adrenergic agonist or endothelin.
The invention features a therapeutic method for treatment or prevention of ventricular muscle cell hypertrophy-mediated heart failure in a mammal comprising administering an therapeutically effective amount of a retinoic acid compound. In one embodiment, the therapeutic method of treating heart failure includes treating or preventing &agr;
1
-adrenergic-mediated ventricular muscle cell hypertrophy. In another embodiment, the therapeutic method treats or prevents endothelin-mediated ventricular muscle cell hypertrophy.
Other aspects of the invention will become apparent from the following detailed description and the claims.
REFERENCES:
patent: 5344644 (1994-09-01), Igari et al.
Argentin, Stefania, et al., “Distal cis-Acting Promoter Sequences Mediate Glucocorticoid Stimulation of Cardiac Atrial Natriuretic Factor Gene Transcription,”J. Biol. Chem.,(Dec. 5, 1991) vol. 266, No. 34, pp. 23315-23322.
Argentin, Stefania, et al., “The Gene for Rat Atrial Natriuretic Factor,”J. Biol. Chem.,(Apr. 25, 1985), vol. 260, No. 8, pp. 4568-4571.
Battistini, Bruno, et al., “Growth Regulatory Properties of Endothelins,”Peptides,(1993) vol. 14, pp. 385-399.
Buttrick, Peter, et al., “Effects of chronic dobutamine on cardiac mechanics and biochemistry after myocardial infarction in rats,”Am. J. Phyisol.(1991), pp. H473-H479.
Cherrington, Julie M., et al., “Human Cytomegalovirus ie1 Transactivates the &agr; Promoter-Enhancer via an 18-Base-Pair Repeat Element,”J. Virol.(Mar. 1989), vol. 63, No. 3, pp. 1435-1440.
Chien, Kenneth R., et al., “Regulation of cardiac gene expression during myocardial growth and hypertrophy: molecular studie
Chien Kenneth R.
Zhou Ming Dong
Borden Paula A.
Bozicevic Field & Francis LLP
Francis Carol L.
Marschel Ardin H.
Moran Marjorie A.
LandOfFree
Retinoid suppression of ventricular muscle cell hypertrophy does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Retinoid suppression of ventricular muscle cell hypertrophy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Retinoid suppression of ventricular muscle cell hypertrophy will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2531155