Two cases of apical ballooning syndrome masking apical hypertrophic cardiomyopathy.

Apical akinesis and dilation in the absence of obstructive coronary artery disease is a typical feature of stress-induced (takotsubo) cardiomyopathy, whereas apical hypertrophy is seen in apical-variant hypertrophic cardiomyopathy. We report the cases of 2 patients who presented with takotsubo cardiomyopathy and were subsequently found to have apical-variant hypertrophic cardiomyopathy, after the apical ballooning from the takotsubo cardiomyopathy had resolved. The first patient, a 43-year-old woman with a history of alcohol abuse, presented with shortness of breath, electrocardiographic and echocardiographic features consistent with takotsubo cardiomyopathy, and no significant coronary artery disease.

Comparative proteomics profiling reveals role of smooth muscle progenitors in extracellular matrix production.

Objective: Recent studies on cardiovascular progenitors have led to a new appreciation that paracrine factors may support the regeneration of damaged tissues.

Methods And Results: We used a shotgun proteomics strategy to compare the secretome of peripheral blood-derived smooth muscle progenitors (SPCs) with human aortic smooth muscle cells. The late-outgrowth SPCs produced fewer proteolytic enzymes and inflammatory cytokines and showed reduced invasive capacity.

Proteomics of acute coronary syndromes.

Acute coronary syndromes (ACS), such as unstable angina, acute myocardial infarction, and sudden cardiac death, are commonly associated with the presence of vulnerable plaques in coronary arteries. Rupture or erosion of vulnerable plaques results in the formation of luminal thrombi due to the physical contact between platelets and thrombogenic elements within the atherosclerotic lesions. Considering the socioeconomic burden of ACS, it is imperative that the scientific community achieves a clear understanding of the multifaceted pathophysiology of vulnerable atheroma to identify accurate prognostic biomarkers and therapeutic targets.

Bone marrow-derived myofibroblasts are present in adult human heart valves.

Background And Aim Of The Study: Endothelial, smooth muscle and cardiomyocyte chimerism has been shown to occur in the human heart. It is currently unknown whether the bone marrow contributes to cellular components of adult human heart valves. Here, it was determined whether bone marrow-derived smooth muscle-like cells (SMLC) are present in the heart valves of adult subjects.

Integrin profile and in vivo homing of human smooth muscle progenitor cells.

Background: Recently, we identified circulating smooth muscle progenitor cells (SPCs) in human peripheral blood. The integrin profile of such progenitors is currently unknown and may affect their in vivo homing characteristics. In this study, we determined the integrin profile of vascular progenitors and SPC adhesion to extracellular matrix (ECM) proteins in vitro and in vivo.

Endothelial progenitor cells are decreased in blood of cardiac allograft patients with vasculopathy and endothelial cells of noncardiac origin are enriched in transplant atherosclerosis.

Background: Recent studies in animals suggest that circulating recipient endothelial precursors may participate in the biology of transplant vasculopathy. It is currently unknown whether a similar interaction between recipient endothelial cells and the vessel wall occurs in human subjects undergoing allogeneic cardiac transplantation.

Methods And Results: Circulating endothelial cells and endothelial progenitor cells (EPCs) were quantified in 15 cardiac transplantation subjects with and without angiographic evidence of vasculopathy.

Smooth muscle cells in human coronary atherosclerosis can originate from cells administered at marrow transplantation.

Atherosclerosis is the major cause of adult mortality in the developed world, and a significant contributor to atherosclerotic plaque progression involves smooth muscle cell recruitment to the intima of the vessel wall. Controversy currently exists on the exact origin of these recruited cells. Here we use sex-mismatched bone marrow transplant subjects to show that smooth muscle cells throughout the atherosclerotic vessel wall can derive from donor bone marrow.

Bone marrow-derived cardiomyocytes are present in adult human heart: A study of gender-mismatched bone marrow transplantation patients.

Background: Recent studies have identified cardiomyocytes of extracardiac origin in transplanted human hearts, but the exact origin of these myocyte progenitors is currently unknown.

Methods And Results: Hearts of female subjects (n=4) who had undergone sex-mismatched bone marrow transplantation (BMT) were recovered at autopsy and analyzed for the presence of Y chromosome-positive cardiomyocytes. Four female gender-matched BMT subjects served as controls.

Smooth muscle progenitor cells in human blood.

Background: Recent animal data suggest that vascular smooth muscle cells within the neointima of the vessel wall may originate from bone marrow, providing indirect evidence for circulating smooth muscle progenitor cells (SPCs). Evidence for circulating SPCs in human subjects does not exist, and the mechanism whereby such putative SPCs may home to sites of plaque formation is presently not understood but is likely to involve expression of specific surface adhesion molecules, such as integrins. In this study, we aimed to culture smooth muscle outgrowth cells (SOCs) from SPCs in human peripheral blood and characterize surface integrin expression on these cells.