Control of cardiomyocyte gene expression as drug target

Pflugers Arch - Eur J Physiol

Rominger

et al. 2007

In experimental animals, cardiac work is derived from pressure-volume area and analyzed further using stress-length relations. Lack of methods for determining accurately myocardial mass has until now prevented the use of stress-length relations in patients. We hypothesized, therefore, that not only pressure-volume loops but also stress-length diagrams can be derived from cardiac volume and cardiac mass as assessed by cardiac magnetic resonance imaging (CMR) and invasively measured pressure. Left ventricular (LV) volume and myocardial mass were assessed in seven patients with aortic valve stenosis (AS), eight with dilated cardiomyopathy (DCM), and eight controls using electrocardiogram (ECG)-gated CMR. LV pressure was measured invasively. Pressure-volume curves were calculated based on ECG triggering. Stroke work was assessed as area within the pressure-volume loop. LV wall stress was calculated using a thick-wall sphere model. Similarly, stress-length loops were calculated to quantify stress-length-based work. Taking the LV geometry into account, the normalization with regard to ventricular circumference resulted in "myocardial work." Patients with AS (valve area 0.73+/-0.18 cm(2)) exhibited an increased LV myocardial mass when compared with controls (P<0.05). LV wall stress was increased in DCM but not in AS. Stroke work of AS was unchanged when compared with controls (0.539+/-0.272 vs 0.621+/-0.138 Nm, not significant), whereas DCM exhibited a significant depression (0.367+/-0.157 Nm, P<0.05). Myocardial work was significantly reduced in both AS and DCM when compared with controls (129.8+/-69.6, 200.6+/-80.1, 332.2+/-89.6 Nm/m(2), P<0.05), also after normalization (7.40+/-5.07, 6.27+/-3.20, 14.6+/-4.07 Nm/m(2), P<0.001). It is feasible to obtain LV pressure-volume and stress-length diagrams in patients based on the present novel methodological approach of using CMR and invasive pressure measurement. Myocardial work was reduced in patients with DCM and noteworthy also in AS, while stroke work was reduced in DCM only. Most likely, deterioration of myocardial work is crucial for the prognosis. It is suggested to include these basic physiological procedures in the clinical assessment of the pump function of the heart.

Section: Left Ventricular Wall Stress and Heart Failurementioning

confidence: 99%

A new methodological approach to assess cardiac work by pressure–volume and stress–length relations in patients with aortic valve stenosis and dilated cardiomyopathy

Alter

Pflugers Arch - Eur J Physiol

Rominger

et al. 2007

“…During our screening studies on drugs which increase the expression of the myosin isoform V1 and sarcoplasmic reticulum Ca 2+ uptake, we observed that interventions which increase glucose utilization have a potent action on myosin heavy-chain expression [108]. Although these findings might have been unexpected, they can be rationalized in view of the apparent need of the cardiocyte to match gene expression of key proteins with the energetic status.…”

Section: Introductionmentioning

confidence: 95%

The Use of Partial Fatty Acid Oxidation Inhibitors for Metabolic Therapy of Angina Pectoris and Heart Failure

Zarain‐Herzberg

Maisch

2002

Herz

Self Cite

Partial fatty acid oxidation inhibitors have raised great interest since they are expected to counteract a dysregulated gene expression of hypertrophied cardiocytes. Some of these compounds have been developed for treating non-insulin-dependent diabetes mellitus and stable angina pectoris. A shift from fatty acid oxidation to glucose oxidation leads to a reduced gluconeogenesis and improved economy of cardiac work. An increased glucose oxidation can be achieved with the following enzyme inhibitors: etomoxir, oxfenicine, methyl palmoxirate, S-15176, metoprolol, amiodarone, perhexiline (carnitine palmitoyltransferase-1); aminocarnitine, perhexiline (carnitine palmitoyltransferase-2); hydrazonopropionic acid (carnitine-acylcarnitine translocase); MET-88 (gamma-butyrobetaine hydroxylase); 4-bromocrotonic acid, trimetazidine, possibly ranolazine (thiolases); hypoglycin (butyryl-CoA dehydrogenase); dichloroacetate (pyruvate dehydrogenase kinase). CLINICAL TRIALS with trimetazidine and ranolazine showed that this shift in substrate oxidation has an antianginal action. Etomoxir and MET-88 improved the function of overloaded hearts by increasing the density of the Ca(2+) pump of sarcoplasmic reticulum (SERCA2). The promoters of SERCA2 and alpha-myosin heavy-chain exhibit sequences which are expected to respond to transcription factors responsive to glucose metabolites and/or peroxisome proliferator-responsive element (PPAR) agonists. Further progress in elucidating novel compounds which upregulate SERCA2 expression is closely linked to the characterization of regulatory sequences of the SERCA2 promoter.

“…In langjährigen Untersuchungen prüften wir eine Reihe pharmakologischer Interventionen zur Beeinflussung der Genexpression des normalen und druckbelasteten Kardiozyten [23]. Im Mittelpunkt stand die Frage, ob Veränderungen in der Genexpression Auswirkungen auf die Funktion des Herzens haben.…”

Section: Genexpression Des Kardiozyten Als Pharmakologisches Target Eunclassified

Funktionelle Genomik des druckbelasteten Kardiozyten: Etomoxir bei Herzinsuffizienz?

Maisch

2002

Herz

Self Cite

Drugs in development (CPT-1 inhibitor/PPARalpha activator) that increase glucose oxidation can enhance SERCA2 expression. The lead compound etomoxir had a selective influence on the contraction and relaxation rate of pressure-overloaded hearts. The functional parameters were correlated with the proportion of alpha-myosin heavy chains. Since viral or inflammatory injury of the heart can also induce a fetal phenotype, metabolic modulators such as etomoxir represent a promising therapeutic approach also for cardiomyopathies with inadequate SERCA2 expression.