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Mitchell S Finkel

Publications and source records attributed to Mitchell S Finkel.

10 recordsLinked to original sources
PubMed2005

iPLA2 inhibitor blocks negative inotropic effect of HIV gp120 on cardiac myocytes.

Recent improvements in survival from AIDS have been accompanied by an increased recognition of the potential importance of other manifestations of HIV infection, including cardiomyopathy. Mechanisms responsible for HIV cardiomyopathy are unknown, but may include direct effects of HIV proteins on the heart. We previously provided support for direct effects of HIV proteins by demonstrating a negative inotropic effect of the HIV coat protein, gp120, on isolated adult rat ventricular myocytes (ARVM). We now report that this negative inotropic effect of HIV gp120 is mediated by a signaling pathway involving p38 MAP kinase, iPLA2 and troponin I. Exposure of ARVM to HIV gp120 resulted in maximal activation of iPLA2 by 60 min as reflected in hydrolysis of arachidonyl thiophosphatidylcholine that was completely blocked by the iPLA2 inhibitor, bromoenol lactone (BEL) or the p38 MAP kinase inhibitor, SB203580. The negative inotropic effect of gp120 was blocked by BEL, as well as SB203580. BEL did not block gp120 stimulated phosphorylation of p38 MAP kinase itself, and/or its downstream effectors, ATF2 or MAPKAP2. However, BEL did block gp120-stimulated phosphorylation of troponin I. Thus, the negative inotropic effect of HIV gp120 requires activation of p38 MAP kinase and iPLA2; as well as troponin I phosphorylation. Activation of this novel p38 MAP kinase-iPLA2-troponin I signaling pathway may contribute to HIV cardiomyopathy.

Activating Transcription Factor 2↗
PubMed2004

p38 MAP kinase inhibitor reverses stress-induced cardiac myocyte dysfunction.

Stress is gaining increasing acceptance as an independent risk factor contributing to adverse cardiovascular outcomes. Potential mechanisms responsible for the deleterious effects of stress on the development and progression of cardiovascular disease remain to be elucidated. An established animal model of stress in humans is the prenatally stressed (PS) rat. We stressed rats in their third trimester of pregnancy by daily injections of saline and moving from cage to cage. Male offspring of these stressed dams (PS) and age-matched male control offspring (control) were further subjected to restraint stress (R) at 6 and 7 wk of age. Echocardiography revealed a significant decrease in fractional shortening in PS + R vs. controls + R (45.8 +/- 3.9 vs. 61.9 +/- 2.4%, PS + R vs. controls + R; P < 0.01; n = 12). Isolated adult rat ventricular myocytes from PS + R also revealed diminished fractional shortening (6.7 +/- 0.8 vs. 12.7 +/- 1.1%, PS + R vs. controls + R; P < 0.01; n = 24) and blunted inotropic responses to isoproterenol (P < 0.01; n = 24) determined by automated border detection. The p38 mitogen-activated protein (MAP) kinase inhibitor SB-203580 blocked p38 MAP kinase phosphorylation, reversed the depression in fractional shortening, and partially ameliorated the blunted adrenergic signaling seen in adult rat ventricular myocytes from PS + R. Phosphorylation of p38 MAP kinase in cardiac myocytes by stress may be sufficient to lead to myocardial dysfunction in animal models and possibly humans.

Animals↗
PubMed2004

p38 MAP kinase-mediated negative inotropic effect of HIV gp120 on cardiac myocytes.

Myocardial dysfunction leading to dilated cardiomyopathy has been documented with surprisingly high frequency in human immunodeficiency virus (HIV)-infected individuals. p38 MAP kinase has been implicated as a mediator of myocardial dysfunction. We previously reported p38 MAP kinase activation by the HIV coat protein gp120 in neonatal rat cardiac myocytes. We now report the direct inotropic effects of HIV gp120 on adult rat ventricular myocytes (ARVM). ARVM were continuously superfused with gp120, and percent fractional shortening (FS) was determined by automated border detection and simultaneous intracellular ionized free Ca2+ concentration ([Ca2+]i) measured by fura 2-AM fluorescence: gp120 alone increased FS and increased [Ca2+]i within 5 min and then depressed FS without a decrease in [Ca2+]i by 20-60 min, which persisted for at least 2 h. Exposure of ARVM to gp120 also resulted in the phosphorylation of the upstream regulator of p38 MAP kinase MKK3/6, p38 MAP kinase itself, and its downstream effector, ATF-2, over a similar time course. ERK (p44/42) and JNK stress signaling pathways were not similarly activated. The effects of the p38 MAP kinase inhibitor were concentration dependent. SB-203580 (10 microM) blocked both p38 MAP kinase phosphorylation and the delayed negative inotropic effect of gp120. SB-203580 (5 microM) selectively blocked phosphorylation of ATF-2 without blocking the phosphorylation of MKK3/6 or p38 MAP kinase itself. SB-203580 (5 microM) administered before, with, or after gp120 blocked the negative inotropic effect of gp120 in ARVM. p38 MAP kinase activation may be a common stress-response mechanism contributing to myocardial dysfunction in HIV and other nonischemic as well as ischemic cardiomyopathies.

Activating Transcription Factors↗
PubMed2003

Platelet/endothelial biomarkers in depressed patients treated with the selective serotonin reuptake inhibitor sertraline after acute coronary events: the Sertraline AntiDepressant Heart Attack Randomized Trial (SADHART) Platelet Substudy.

BACKGROUND: Depression after acute coronary syndromes (ACSs) has been identified as an independent risk factor for subsequent cardiac death. Enhanced platelet activation has been hypothesized to represent 1 of the mechanisms underlying this association. Selective serotonin reuptake inhibitors (SSRIs) are known to inhibit platelet activity. Whether treatment of depressed post-ACS patients with SSRIs alters platelet function was not known. Accordingly, we serially assessed the release of established platelet/endothelial biomarkers in patients treated with sertraline vs placebo in the Sertraline AntiDepressant Heart Attack Randomized Trial (SADHART). METHODS AND RESULTS: Plasma samples (baseline, week 6, and week 16) were collected from patients randomized to sertraline (n=28) or placebo (n=36). Anticoagulants, aspirin, and ADP-receptor inhibitors were permitted in this study. Platelet factor 4, beta-thromboglobulin (betaTG), platelet/endothelial cell adhesion molecule-1, P-selectin, thromboxane B2, 6-ketoprostaglandin F1a, vascular cell adhesion molecule-1, and E-selectin were measured by ELISA. Treatment with sertraline was associated with substantially less release of platelet/endothelial biomarkers than was treatment with placebo. These differences attained statistical significance for betaTG (P=0.03) at weeks 6 and 16 and for P-selectin (P=0.04) at week 16. Repeated-measures ANOVA revealed a significant advantage for sertraline vs placebo for diminishing E-selectin and betaTG concentrations across the entire treatment period. CONCLUSIONS: Treatment with sertraline in depressed post-ACS patients is associated with reductions in platelet/endothelial activation despite coadministration of widespread antiplatelet regimens including aspirin and clopidogrel. The antiplatelet and endothelium-protective properties of SSRIs might represent an attractive additional advantage in patients with depression and comorbid coronary artery and/or cerebrovascular disease.

Biomarkers↗
PubMed2003

Inflammatory mediators and reversible myocardial dysfunction.

A variety of seemingly unrelated clinical conditions manifest the same effects on the heart. These effects include: (1) reversible myocardial dysfunction, (2) beta-adrenergic desensitization, and (3) activation of inflammatory mediators. We provide evidence supporting a role for cytokines, mitogen activated protein kinases (MAP kinases), and nitric oxide (NO) as common mediators of reversible myocardial dysfunction and beta-adrenergic desensitization. Data from animal models and human studies support a pathogenic role for these inflammatory mediators in ischemic as well as non-ischemic myocardial dysfunction. It is suggested that compensatory cellular programs are activated to provide short-term protection from brief periods of ischemia and infection. Continuous activation of these compensatory pathways leads to cardiomyopathy and chronic (congestive) heart failure. Elucidating the signaling pathways involved has the potential to provide the opportunity to exploit the cardioprotective advantages of these agents without bearing the burden of excessive stimulation.

Animals↗
PubMed2003

Enhanced platelet/endothelial activation in depressed patients with acute coronary syndromes: evidence from recent clinical trials.

Platelets play a key role in the progression of acute coronary syndromes (ACS). Clinical depression alone is also associated with enhanced platelet activation. The purpose of this study was to compare concentrations of established biomarkers of enhanced platelet/endothelial activation in clinically depressed versus non-depressed patients enrolled in recent clinical trials for ACS. Two hundred and eighty-one baseline plasma samples from patients with acute myocardial infarction (ASSENT-2; n = 41), with ACS (PRONTO; n = 126) and with clinical depression plus previous acute coronary syndrome within 6 months (SADHART; n = 64), and from normal healthy controls (n = 50) were analyzed. Blood was drawn before applying any therapeutic strategies including interventions, thrombolytics, infusions, and selective serotonin re-uptake inhibitors. Platelet factor 4, beta-thromboglobulin, platelet/endothelial cell adhesion molecule-1, P-selectin, thromboxane, prostacyclin, vascular cell adhesion molecule-1, and E-selectin were measured by enzyme-linked immunosorbent assay by a single core laboratory. Patients with ACS exhibited a higher degree of platelet activation than controls independently of the presence of depression. Plasma levels of P-selectin, thromboxane, prostacyclin, and vascular cell adhesion molecule-1 were the highest in the acute myocardial infarction group when compared with ACS despite the presence or absence of clinical depression. Surprisingly, patients with ACS and depression exhibited the highest levels of platelet factor 4, beta-thromboglobulin, and platelet/endothelial cell adhesion molecule-1 when compared with myocardial infarction or angina patients without clinical depression. E-selectin plasma level was constantly elevated compared with controls but did not differ among the groups dependent on the incidence of depression. The depressed plus ACS group had higher plasma levels of all biomarkers compared with the non-depressed patients. Retrospective analysis of the data from several clinical trials reveals that clinical depression is associated with enhanced activation of platelet/endothelial biomarkers even above the level expected in ACS. These findings may contribute to the unfavorable outcome associated with clinical depression in patients with ACS.

Acute Disease↗
PubMed2003

Cardiovascular health and depression.

Research has shown that depression increases the likelihood that otherwise healthy people will develop ischemic heart disease (IHD) and worsens the prognosis of patients who already have IHD. Moreover, concerns about safety (e.g., cardiac side effects, drug-drug interactions) have caused physicians to be hesitant about using antidepressant agents in patients with IHD. This article is based on a recent roundtable of experts who met to discuss risk, diagnosis, and treatment options for depression in patients with IHD. This article reviews clinical and epidemiological studies that have described a link between depression and the subsequent development of IHD and have examined the role of depression as a predictor of cardiac events in patients with existing IHD. The article addresses the issue of whether depression can be safely and efficaciously treated both in patients with stable IHD and in those with acute coronary syndromes. The authors discuss safety issues related to the potential for interactions between antidepressants and cardiovascular medications, the use of nonpharmacologic treatment options such as psychosocial interventions, and the effect of antidepressant therapy on quality of life in patients with IHD. The article concludes with practical clinical guidance concerning the management of depression in patients who have recently experienced myocardial infarction.

Journal Article↗
PubMed2002

Sertraline treatment of major depression in patients with acute MI or unstable angina.

CONTEXT: Major depressive disorder (MDD) occurs in 15% to 23% of patients with acute coronary syndromes and constitutes an independent risk factor for morbidity and mortality. However, no published evidence exists that antidepressant drugs are safe or efficacious in patients with unstable ischemic heart disease. OBJECTIVE: To evaluate the safety and efficacy of sertraline treatment of MDD in patients hospitalized for acute myocardial infarction (MI) or unstable angina and free of other life-threatening medical conditions. DESIGN AND SETTING: Randomized, double-blind, placebo-controlled trial conducted in 40 outpatient cardiology centers and psychiatry clinics in the United States, Europe, Canada, and Australia. Enrollment began in April 1997 and follow-up ended in April 2001. PATIENTS: A total of 369 patients with MDD (64% male; mean age, 57.1 years; mean 17-item Hamilton Depression [HAM-D] score, 19.6; MI, 74%; unstable angina, 26%). INTERVENTION: After a 2-week single-blind placebo run-in, patients were randomly assigned to receive sertraline in flexible dosages of 50 to 200 mg/d (n = 186) or placebo (n = 183) for 24 weeks. MAIN OUTCOME MEASURES: The primary (safety) outcome measure was change from baseline in left ventricular ejection fraction (LVEF); secondary measures included surrogate cardiac measures and cardiovascular adverse events, as well as scores on the HAM-D scale and Clinical Global Impression Improvement scale (CGI-I) in the total randomized sample, in a group with any prior history of MDD, and in a more severe MDD subgroup defined a priori by a HAM-D score of at least 18 and history of 2 or more prior episodes of MDD. RESULTS: Sertraline had no significant effect on mean (SD) LVEF (sertraline: baseline, 54% [10%]; week 16, 54% [11%]; placebo: baseline, 52% [13%]; week 16, 53% [13%]), treatment-emergent increase in ventricular premature complex (VPC) runs (sertraline: 13.1%; placebo: 12.9%), QTc interval greater than 450 milliseconds at end point (sertraline: 12%; placebo: 13%), or other cardiac measures. All comparisons were statistically nonsignificant (P> or = .05). The incidence of severe cardiovascular adverse events was 14.5% with sertraline and 22.4% with placebo. In the total randomized sample, the CGI-I (P =.049), but not the HAM-D (P =.14), favored sertraline. The CGI-I responder rates for sertraline were significantly higher than for placebo in the total sample (67% vs 53%; P =.01), in the group with at least 1 prior episode of depression (72% vs 51%; P =.003), and in the more severe MDD group (78% vs 45%; P =.001). In the latter 2 groups, both CGI-I and HAM-D measures were significantly better in those assigned to sertraline. CONCLUSION: Our results suggest that sertraline is a safe and effective treatment for recurrent depression in patients with recent MI or unstable angina and without other life-threatening medical conditions.

Angina, Unstable↗