Low density lipoprotein receptor-related protein 1 is upregulated in epicardial fat from type 2 diabetes mellitus patients and correlates with glucose and triglyceride plasma levels.

Lipoprotein receptor expression plays a crucial role in the pathophysiology of adipose tissue in in vivo models of diabetes. However, there are no studies in diabetic patients. The aims of this study were to analyze (a) low-density lipoprotein receptor-related protein 1 (LRP1) and very low-density lipoprotein receptor (VLDLR) expression in epicardial and subcutaneous fat from type 2 diabetes mellitus compared with nondiabetic patients and (b) the possible correlation between the expression of these receptors and plasmatic parameters. Adipose tissue biopsy samples were obtained from diabetic (n = 54) and nondiabetic patients (n = 22) undergoing cardiac surgery before the initiation of cardiopulmonary bypass. Adipose LRP1 and VLDLR expression was analyzed at mRNA level by real-time PCR and at protein level by Western blot analysis. Adipose samples were also subjected to lipid extraction, and fat cholesterol ester, triglyceride, and free cholesterol contents were analyzed by thin-layer chromatography. LRP1 expression was higher in epicardial fat from diabetic compared with nondiabetic patients (mRNA 17.63 ± 11.37 versus 7.01 ± 4.86; P = 0.02; protein 11.23 ± 7.23 versus 6.75 ± 5.02, P = 0.04). VLDLR expression was also higher in epicardial fat from diabetic patients but only at mRNA level (231.25 ± 207.57 versus 56.64 ± 45.64, P = 0.02). No differences were found in the expression of LRP1 or VLDLR in the subcutaneous fat from diabetic compared with nondiabetic patients. Epicardial LRP1 and VLDLR mRNA overexpression positively correlated with plasma triglyceride levels (R(2) = 0.50, P = 0.01 and R(2) = 0.44, P = 0.03, respectively) and epicardial LRP1 also correlated with plasma glucose levels (R(2) = 0.33, P = 0.03). These results suggest that epicardial overexpression of certain lipoprotein receptors such as LRP1 and VLDLR expression may play a key role in the alterations of lipid metabolism associated with type 2 diabetes mellitus.

Cardiomyogenic differentiation of human bone marrow mesenchymal cells: Role of cardiac extract from neonatal rat cardiomyocytes.

Bone marrow mesenchymal stromal cells (BM-MSCs) with regenerative potential have been identified in heart. Whether these cells become new cardiac lineage cells by phenomena of transdifferentiation or fusion is also being investigated. Although, these mechanisms give cardiomyocytes, it has to be considered that MSCs transplantation could carry out ossification and calcification processes. An alternative might be the use of myocytes; however, the problem is the arrythmia. For those reasons, is that we investigated how to obtain cardiomyocyte-like cells from human MSCs (hMSCs). The aim of the present work was to evaluate a nuclear reprogramming of the hMSCs by a neonatal rat cardiomyocytes extract (EX) using Streptolysin O (SLO) treatment. hMSCs treated with 57.5ng/ml SLO presented ball-like, stick-like and myotube-like morphology. In the absence of cardiomyogenic stimuli, hMSCs expressed markers of cardiac phenotype-like sarcomeric alpha-actinin, connexin-43 and GATA-4. However, when hMSCs were treated with SLO+EX or 10 microM of 5-azacytidine (5-AZA), the expression of these markers were significantly increased and furthermore, expressed SERCA-2, cardiac Troponin I, beta-MyHC, desmin, MLC-2a and MLC-2v thus showing the phenotype of mature cardiomyocytes. PCR analysis showed that cardiomyocyte-related genes, such as beta1-adrenergic receptor (beta1-AR), MLC-2a and cardiac Troponin T, were expressed after SLO+EX treatment like with 5-AZA. We concluded that the extract of neonatal rat cardiomyocytes could promote a nuclear modification of hMSCs to cardiomyogenic-like cells differentiation. Since the 5-AZA treatment appears to be genotoxic and taking into account the obtained results, the nuclear reprogramming by cell extract may be an approach leading to the identification of soluble factors that drives the reprogramming.

Hemosiderin deposits confounds tracking of iron-oxide-labeled stem cells: an experimental study.

BACKGROUND: The aim of the present research was to study the possible interference of hemosiderin deposits with the histological detection of dextran-coated, iron-labeled, mesenchymal stem cells after intracoronary administration in a porcine model of myocardial infarction. MATERIALS AND METHODS: A myocardial infarction was induced in six animals that received intracoronary iron-labeled autologous mesenchymal stem cells (group 1; n = 2) or placebo (group 2; n = 4). Six control animals without myocardial infarction underwent direct intramyocardial injections of iron-labeled autologous mesenchymal stem cells (group 3; n = 2) or placebo (group 4; n = 4). Histological sections from explanted hearts were stained with Prussian blue to identify dextran-coated, iron-labeled, mesenchymal stem cells. RESULTS: After Prussian blue staining, granular blue labeling in the tissue was observed in both groups of animals with infarcts. Similar granular blue labeling was detected in hearts from control animals without infarction that had received iron-labeled mesenchymal stem cells. However, hearts from control animals without infarction that received placebo did not have any granular blue labeling in the tissue. CONCLUSIONS: Hemosiderin from infarction hemorrhage interferes with detection of dextran-coated iron-labeled mesenchymal stem cells after intracoronary administration, suggesting that this marker is not useful to detect mesenchymal stem cells in a porcine model of myocardial infarction.

Umbilical cord blood-derived stem cells spontaneously express cardiomyogenic traits.

BACKGROUND: Umbilical cord blood (UCB) has been widely used for hematopoietic stem cell transplantation. The UCB-derived stem cells (UCBSCs) have been proposed as an alternative to bone marrow (BM)-derived mesenchymal stem cells (MSCs) for cardiac cell-based therapy. Herein we studied whether UCBSCs spontaneously exhibit cardiac-specific markers in vitro. METHODS: Human UCBSCs were isolated, expanded, and phenotyped by flow cytometry, quantitative RT-PCR, and immunofluorescence. Cell pluripotency and proliferation were also assessed by adipogenic and osteogenic media and in growth assays. RESULTS: Among 25 analyzed UCB, 16% of cases afforded primary culture satisfactory generation of UCBSCs. Duplication time (Td) of cultures was 2.16 +/- 0.06 days. The cells were strongly positive for CD105 (18.5 +/- 0.14), CD44 (27 +/- 2.8), CD166 (13 +/- 9), CD29 (59 +/- 9.4), CD90 (60 +/- 11) and consistently negative for CD117 (1.2 +/- 0.1), CD106 (1.1 +/- 0), CD34 (1.2 +/- 0.2), CD14 (1 +/- 0), and CD45 (1 +/- 0), consistent with a mesenchymal lineage. Adipogenesis and osteogenesis of cells resulted in low accumulation of intracellular lipid droplets and high deposition of calcium. The UCBSCs showed gene transcripts for alpha-actinin, connexin (Cx)-43, SERCA-2, and stromal cell-derived factor (SDF)-1alpha. At the protein level, the cells abundantly expressed alpha-actinin, Cx-43, SERCA-2 and SDF-1alpha. In contrast, these cells did not express the cardiac transcription factors GATA-4, Tbx5, and Nkx2.5, nor the sarcomeric proteins beta-myosin heavy chain (beta-MyHC) or cardiac troponin I (cTnI). CONCLUSIONS: Human UCBSCs may represent an alternative source of stem cells for myocardial-cell replacement. These cells can be highly expanded. They spontaneously express proteins of paramount importance for cardiovascular regeneration, such as Cx-43, SERCA-2, and SDF-1alpha.

Identification of cardiomyogenic lineage markers in untreated human bone marrow-derived mesenchymal stem cells.

BACKGROUND: Recent reports refute the classic paradigm by which human heart is unable to repair itself following disease or injury. Cardiac and noncardiac stem cells with cardiac regeneration potential have been documented. We studied whether untreated mesenchymal stem cells express markers of cardiomyogenic lineage in vitro. METHODS: Mesenchymal stem cells were obtained from human iliac crest marrow aspirates. Cells were isolated and characterized using flow cytometry by surface expression of CD105, CD166, CD29, CD44, CD14, and CD34. To evaluate their cardiomyogenic potential, presence of cardiac proteins (cardiac troponin I, sarcomeric alpha-actinin, beta myosin heavy chain (beta-MyHC), connexin-43, and SERCA-2), and transcription factors (GATA-4) were assessed. RESULTS: Mesenchymal stem cells expressed CD105 (4.25 +/- 0.35), CD166 (27.83 +/- 1.89), and CD29 (9.4 +/- 0.57) and were negative for CD34, CD14, and CD45. In absence of additional stimuli in the culture media, these cells expressed connexin-43, alpha-actinin, and GATA-4, and were negative for SERCA-2, cardiac troponin I, and beta-MyHC. CONCLUSIONS: Human adult mesenchymal stem cells spontaneously exhibit markers of cardiac phenotype in vitro. In the appropiate myocardial environment, these cells may transdifferentiate into mature cardiomyocytes.

Gene therapy for myocardial angiogenesis: has it come of age?

Vasculogenesis and angiogenesis are the processes responsible for the development of the circulatory system during embryonic and adult life. Vasculogenesis occurs during embryogenesis while angiogenesis refers to blood vessel formation from any preexisting vasculature. Postnatal angiogenesis resumes during reproduction, wound healing, and ischemia. Excess blood vessel formation may contribute to initiating and maintaining many diseases such as chronic inflammatory disorders, tumor growth, restenosis, and atherosclerosis. In contrast. insufficient blood vessel formation is responsible for tissue ischemia, as in coronary artery disease. An increasing number of patients with advanced coronary artery disease remain symptomatic despite maximal interventional, surgical or medical treatment. Ideally, they would benefit most from additional arterial blood supply to ischemic areas of myocardium. Therapeutic angiogenesis, the ability to induce the growth of new blood vessels, is one of the most intriguing new frontiers in interventional cardiology for this growing patient group. Several approaches are currently undergoing intensive experimental investigations or have already entered early clinical trials involving either local angiogenic peptide administration or the transfection of angiogenic genes. Gene therapy for therapeutic myocardial angiogenesis is the most promising synthesis of two emerging technologies. In the following article, we will review the fundamental pathophysiological concepts of gene-based angiogenic therapy, the technical approaches and delivery systems, and the results of the first clinical trials. We will also discuss the controversies and unresolved issues of this new revascularization therapy.

Effects of progestogens on thrombosis and atherosclerosis.

In contrast with past practice, current hormone replacement usually includes a combination of oestrogens and progestogens. In this article, we review the effect of progestins on haemostasis and in the development of atherosclerosis. Second-generation progestogens produce minor haemostatic changes, and in lipid metabolism they decrease the synthesis of triglycerides and very low density lipoproteins (VLDL) and stimulate hepatic lipoprotein lipase. In combination, progestogens modify the effect of oestrogens on hepatic metabolism, endothelium and platelets. Several new progestins (known as third-generation) have less effect on lipid profiles. In vessel walls, animal studies have shown that progestogens are able dose-dependently to inhibit the beneficial effect of oestrogen without significant changes in lipid concentrations. The endothelium-dependent vasoconstrictor effect of progestogens on the arterial wall has been also evaluated. Large epidemiological studies show a two-fold increase in risk of venous thromboembolism with the use of third-generation progestins. Regarding the risk of myocardial infarction, no definite evidence is yet available with the use of third-generation progestins. The clinical consequence is therefore that second-generation progestins are the first choice in prescription for first-time users.

[Tricuspid and pulmonary valve in a case of carcinoid syndrome]. / Afectación valvular tricuspídea y pulmonar en un caso de síndrome carcinoide.

The presence of liver methastasis and serotonin in plasma in the carcinoid tumor are responsible for the carcinoid syndrome. We present a case of tricuspid and pulmonary valvular disease secondary to this syndrome. The finding of liver hyperechogenic nodules added to the described valvular disease by subcostal echocardiogram oriented the diagnosis.

Risk stratification after myocardial infarction: role of electrical instability, ischemia, and left ventricular function.

The problem of risk stratification after myocardial infarction is reviewed. There are three major complications: new ischemic events, congestive heart failure, and malignant arrhythmias and sudden death, related to the presence of residual ischemia, left ventricular dysfunction, and electrical instability. The bidirectional interactions among these three factors is analyzed. The risk is in the middle of a triangle, the three angles of which are the above-mentioned factors. All the "satellite" factors that appear from all three angles are presented. Furthermore, the most important parameters and techniques employed to detect risk, multifactorial approach of risk stratification, and changes of risk stratification in the thrombolytic era are briefly reviewed.