Enca Martin-Rendon

Autologous bone marrow stem cells to treat acute myocardial infarction: a systematic review.

AIMS To provide systematic assessment of the safety and efficacy of autologous bone marrow-derived stem cell (BMSC) transplantation in acute myocardial infarction (AMI) based on clinical evidence. METHODS AND RESULTS The search strategy included MEDLINE, EMBASE, the Cochrane Library, and Current Controlled Trials Register through to August 2007 for randomized controlled trials of BMSC treatment for AMI. Thirteen trials (14 comparisons) with a total of 811 participants were included. Data were analysed using a random effects model. Overall, stem cell therapy improved left ventricular ejection fraction (LVEF) by 2.99% [95% confidence interval (CI), 1.26-4.72%, P = 0.0007], significantly reduced left ventricular end-systolic volume (LVESV) by 4.74 mL (95% CI, -7.84 to -1.64 mL, P = 0.003), and myocardial lesion area by 3.51% (95% CI, -5.91 to -1.11%, P = 0.004) compared with controls. Subgroup analysis revealed that there was statistical significant difference in LEVF in favour of BMSCs when cells were infused within 7 days following AMI and when the BMSC dose administered was higher than 10(8) BMSCs. In addition, there were trends in favour of benefit for most clinical outcomes examined, although it should be acknowledged that the 95%CI included no significant difference. CONCLUSION Stem cell treatment for AMI still holds promise. Clinically, these data suggest that improvement over conventional therapy can be achieved. Further, adequately powered trials using optimal dosing, longer term outcome assessments, more reliable, and more patient-centred outcomes are required.

Dysbindin, a Novel Coiled-coil-containing Protein That Interacts with the Dystrobrevins in Muscle and Brain

The dystrophin-associated protein complex (DPC) is required for the maintenance of muscle integrity during the mechanical stresses of contraction and relaxation. In addition to providing a membrane scaffold, members of the DPC such as the α-dystrobrevin protein family are thought to play an important role in intracellular signal transduction. To gain additional insights into the function of the DPC, we performed a yeast two-hybrid screen for dystrobrevin-interacting proteins. Here we describe the identification of a dysbindin, a novel dystrobrevin-binding protein. Dysbindin is an evolutionary conserved 40-kDa coiled-coil-containing protein that binds to α- and β-dystrobrevin in muscle and brain. Dystrophin and α-dystrobrevin are co-immunoprecipitated with dysbindin, indicating that dysbindin is DPC-associated in muscle. Dysbindin co-localizes with α-dystrobrevin at the sarcolemma and is up-regulated in dystrophin-deficient muscle. In the brain, dysbindin is found primarily in axon bundles and especially in certain axon terminals, notably mossy fiber synaptic terminals in the cerebellum and hippocampus. These findings have implications for the molecular pathology of Duchenne muscular dystrophy and may provide an alternative route for anchoring dystrobrevin and the DPC to the muscle membrane.

5‐Azacytidine‐treated human mesenchymal stem/progenitor cells derived from umbilical cord, cord blood and bone marrow do not generate cardiomyocytes in vitro at high frequencies

Background and Objectives  Mesenchymal stem/progenitor cells (MSCs) are multipotent progenitors that differentiate into such lineages as bone, fat, cartilage and stromal cells that support haemopoiesis. Bone marrow MSCs can also contribute to cardiac repair, although the mechanism for this is unclear. Here, we examine the potential of MSCs from different sources to generate cardiomyocytes in vitro, as a means for predicting their therapeutic potential after myocardial infarction.

Transcriptional Profiling of Human Cord Blood CD133+ and Cultured Bone Marrow Mesenchymal Stem Cells in Response to Hypoxia

Umbilical cord blood (UCB) and bone marrow (BM)‐derived stem and progenitor cells possess two characteristics required for successful tissue regeneration: extensive proliferative capacity and the ability to differentiate into multiple cell lineages. Within the normal BM and in pathological conditions, areas of hypoxia may have a role in maintaining stem cell fate or determining the fine equilibrium between their proliferation and differentiation. In this study, the transcriptional profiles and proliferation and differentiation potential of UCB CD133+ cells and BM mesenchymal cells (BMMC) exposed to normoxia and hypoxia were analyzed and compared. Both progenitor cell populations responded to hypoxic stimuli by stabilizing the hypoxia inducible factor (HIF)‐1α protein. Short exposures to hypoxia increased the clonogenic myeloid capacity of UCB CD133+ cells and promoted a significant increase in BMMC number. The differentiation potential of UCB CD133+ clonogenic myeloid cells was unaltered by short exposures to hypoxia. In contrast, the chondrogenic differentiation potential of BMMCs was enhanced by hypoxia, whereas adipogenesis and osteogenesis were unaltered. When their transcriptional profiles were compared, 183 genes in UCB CD133+ cells and 45 genes in BMMC were differentially regulated by hypoxia. These genes included known hypoxia‐responsive targets such as BNIP3, PGK1, ENO2, and VEGFA, and other genes not previously described to be regulated by hypoxia. Several of these genes, namely CDTSPL, CCL20, LSP1, NEDD9, TMEM45A, EDG‐1, and EPHA3 were confirmed to be regulated by hypoxia using quantitative reverse transcriptase polymerase chain reaction. These results, therefore, provide a global view of the signaling and regulatory network that controls oxygen sensing in human adult stem/progenitor cells derived from hematopoietic tissues.

Meta-Analysis of Cell Therapy Trials for Patients With Heart Failure

RATIONALE Cell-based therapies are a promising intervention for the treatment of heart failure (HF) secondary to ischemic and nonischemic cardiomyopathy. However, the clinical efficacy of such new treatment requires further evaluation. OBJECTIVE To assess available clinical evidence on the safety and efficacy of cell-based therapies for HF. METHODS AND RESULTS Electronic databases (CENTRAL, DARE, NHSEED & HTA, PubMed, MEDLINE, EMBASE, CINAHL, LILACS, KoreaMed, PakMediNet, IndMed, and the Transfusion Evidence Library) were searched for relevant randomized controlled trials to June 2014. Trials of participants with HF and where the administration of any dose of autologous cells by any delivery route was compared with no intervention or placebo were eligible for inclusion. Primary outcomes were defined as mortality and rehospitalization as a result of HF. Secondary outcomes included performance status, quality of life, incidence of arrhythmias, brain natriuretic peptide levels, left ventricular ejection fraction, myocardial perfusion, and adverse events. Thirty-one independent trials (1521 participants) were included. The treatment significantly reduced the risk of mortality and rehospitalization caused by HF. There was a significant improvement in favor of stem cell treatment in performance status and exercise capacity, left ventricular ejection fraction, and quality of life. The treatment was also associated with a reduction of brain natriuretic peptide levels and no increase in the incidence of arrhythmias. However, there was considerable risk of performance, selection, and reporting bias among the included trials. CONCLUSIONS This study shows evidence that autologous cell therapy may be beneficial for patients having HF, but further evidence is required.

Iron particles for noninvasive monitoring of bone marrow stromal cell engraftment into, and isolation of viable engrafted donor cells from, the heart.

Stem cells offer a promising approach to the treatment of myocardial infarction and prevention of heart failure. We have used iron labeling of bone marrow stromal cells (BMSCs) to noninvasively track cell location in the infarcted rat heart over 16 weeks using cine‐magnetic resonance imaging (cine‐MRI) and to isolate the BMSCs from the grafted hearts using the magnetic properties of the donor cells. BMSCs were isolated from rat bone marrow, characterized by flow cytometry, transduced with lentiviral vectors expressing green fluorescent protein (GFP), and labeled with iron particles. BMSCs were injected into the infarct periphery immediately following coronary artery ligation, and rat hearts were imaged at 1, 4, 10, and 16 weeks postinfarction. Signal voids caused by the iron particles in the BMSCs were detected in all rats at all time points. In mildly infarcted hearts, the volume of the signal void decreased over the 16 weeks, whereas the signal void volume did not decrease significantly in severely infarcted hearts. High‐resolution three‐dimensional magnetic resonance (MR) microscopy identified hypointense regions at the same position as in vivo. Donor cells containing iron particles and expressing GFP were identified in MR‐targeted heart sections after magnetic cell separation from digested hearts. In conclusion, MRI can be used to track cells labeled with iron particles in damaged tissue for at least 16 weeks after injection and to guide tissue sectioning by accurately identifying regions of cell engraftment. The magnetic properties of the iron‐labeled donor cells can be used for their isolation from host tissue to enable further characterization.

Meta-Analysis of Cell Therapy Trials for Patients with Heart Failure - An Update

RATIONALE Cell-based therapies are a promising intervention for the treatment of heart failure (HF) secondary to ischemic and nonischemic cardiomyopathy. However, the clinical efficacy of such new treatment requires further evaluation. OBJECTIVE To assess available clinical evidence on the safety and efficacy of cell-based therapies for HF. METHODS AND RESULTS Electronic databases (CENTRAL, DARE, NHSEED & HTA, PubMed, MEDLINE, EMBASE, CINAHL, LILACS, KoreaMed, PakMediNet, IndMed, and the Transfusion Evidence Library) were searched for relevant randomized controlled trials to June 2014. Trials of participants with HF and where the administration of any dose of autologous cells by any delivery route was compared with no intervention or placebo were eligible for inclusion. Primary outcomes were defined as mortality and rehospitalization as a result of HF. Secondary outcomes included performance status, quality of life, incidence of arrhythmias, brain natriuretic peptide levels, left ventricular ejection fraction, myocardial perfusion, and adverse events. Thirty-one independent trials (1521 participants) were included. The treatment significantly reduced the risk of mortality and rehospitalization caused by HF. There was a significant improvement in favor of stem cell treatment in performance status and exercise capacity, left ventricular ejection fraction, and quality of life. The treatment was also associated with a reduction of brain natriuretic peptide levels and no increase in the incidence of arrhythmias. However, there was considerable risk of performance, selection, and reporting bias among the included trials. CONCLUSIONS This study shows evidence that autologous cell therapy may be beneficial for patients having HF, but further evidence is required.

Bone marrow-derived stromal cells home to and remain in the infarcted rat heart but fail to improve function: an in vivo cine-MRI study

Basic and clinical studies have shown that bone marrow cell therapy can improve cardiac function following infarction. In experimental animals, reported stem cell-mediated changes range from no measurable improvement to the complete restoration of function. In the clinic, however, the average improvement in left ventricular ejection fraction is around 2% to 3%. A possible explanation for the discrepancy between basic and clinical results is that few basic studies have used the magnetic resonance (MR) imaging (MRI) methods that were used in clinical trials for measuring cardiac function. Consequently, we employed cine-MR to determine the effect of bone marrow stromal cells (BMSCs) on cardiac function in rats. Cultured rat BMSCs were characterized using flow cytometry and labeled with iron oxide particles and a fluorescent marker to allow in vivo cell tracking and ex vivo cell identification, respectively. Neither label affected in vitro cell proliferation or differentiation. Rat hearts were infarcted, and BMSCs or control media were injected into the infarct periphery (n = 34) or infused systemically (n = 30). MRI was used to measure cardiac morphology and function and to determine cell distribution for 10 wk after infarction and cell therapy. In vivo MRI, histology, and cell reisolation confirmed successful BMSC delivery and retention within the myocardium throughout the experiment. However, no significant improvement in any measure of cardiac function was observed at any time. We conclude that cultured BMSCs are not the optimal cell population to treat the infarcted heart.

Protein glycosylation in disease: new insights into the congenital muscular dystrophies

Glycosylation is the most frequent modification of proteins and is important for many ligand-receptor interactions. Recently, defects in protein glycosylation have been linked to several forms of congenital muscular dystrophy that are frequently associated with brain abnormalities. Muscle-eye-brain disease and Walker-Warburg syndrome are caused by mutations in enzymes involved in O-mannosylation, whereas Fukuyama congenital muscular dystrophy and congenital muscular dystrophy type 1C are caused by mutations in genes that encode putative glycosyltransferases. The common factor in these disorders is defective processing and maturation of a protein called alpha-dystroglycan. This is thought to disrupt the link between alpha-dystroglycan and components of the extracellular matrix, and result in muscle disease and, in many cases, a neuronal-migration disorder.

Bone Marrow Stem Cell Treatment for Ischemic Heart Disease in Patients with No Option of Revascularization: A Systematic Review and Meta-Analysis.

Objective To evaluate bone marrow stem cell treatment (BMSC) in patients with ischemic heart disease (IHD) and no option of revascularization. Background Autologous BMSC therapy has emerged as a novel approach to treat patients with acute myocardial infarction or chronic ischemia and heart failure following percutaneous or surgical revascularization, respectively. However, the effect of the treatment has not been systematic evaluated in patients who are not eligible for revascularization. Methods MEDLINE (1950–2012), EMBASE (1980–2012), CENTRAL (The Cochrane Library 2012, Issue 8) and ongoing trial databases were searched for relevant randomized controlled trials. Trials where participants were diagnosed with IHD, with no option for revascularization and who received any dose of stem cells by any delivery route were selected for inclusion. Study and participant characteristics, details of the intervention and comparator, and outcomes measured were recorded by two reviewers independently. Primary outcome measures were defined as mortality and measures of angina; secondary outcomes were heart failure, quality of life measures, exercise/performance and left ventricular ejection fraction (LVEF). Results Nine trials were eligible for inclusion. BMSC treatment significantly reduced the risk of mortality (Relative Risk 0.33; 95% Confidence Interval 0.17 to 0.65; P = 0.001). Patients who received BMSC showed a significantly greater improvement in CCS angina class (Mean Difference −0.55; 95% Confidence Interval −1.00 to −0.10; P = 0.02) and significantly fewer angina episodes per week at the end of the trial (Mean Difference −5.21; 95% Confidence Interval −7.35 to −3.07; P<0.00001) than those who received no BMSC. In addition, the treatment significantly improved quality of life, exercise/performance and LVEF in these patients. Conclusions BMSC treatment has significant clinical benefit as stand-alone treatment in patients with IHD and no other treatment option. These results require confirmation in large well-powered trials with long-term follow-up to fully evaluate the clinical efficacy of this treatment.