The Effects of Granulocyte Colony-Stimulating Factor in Patients with a Large Anterior Wall Acute Myocardial Infarction to Prevent Left Ventricular Remodeling: A 10-Year Follow-Up of the RIGENERA Study.

BACKGROUND: the RIGENERA trial assessed the efficacy of granulocyte-colony stimulating factor (G-CSF) in the improvement of clinical outcomes in patients with severe acute myocardial infarction. However, there is no evidence available regarding the long-term safety and efficacy of this treatment. METHODS: in order to evaluate the long-term effects on the incidence of major adverse events, on the symptom burden, on the quality of life and the mean life expectancy and on the left ventricular (LV) function, we performed a clinical and echocardiographic evaluation together with an assessment using the Minnesota Living with Heart Failure Questionnaire (MLHFQ) and the Seattle Heart Failure Model (SHFM) at 10-years follow-up, in the patients cohorts enrolled in the RIGENERA trial. RESULTS: thirty-two patients were eligible for the prospective clinical and echocardiography analyses. A significant reduction in adverse LV remodeling was observed in G-CSF group compared to controls, 9% vs. 48% (p = 0.030). The New York Heart Association (NYHA) functional class was lower in G-CSF group vs. controls (p = 0.040), with lower burden of symptoms and higher quality of life (p = 0.049). The mean life expectancy was significantly higher in G-CSF group compared to controls (15 ± 4 years vs. 12 ± 4 years, p = 0.046. No difference was found in the incidence of major adverse events. CONCLUSIONS: this longest available follow-up on G-CSF treatment in patients with severe acute myocardial infarction (AMI) showed that this treatment was safe and associated with a reduction of adverse LV remodeling and higher quality of life, in comparison with standard-of-care treatment.

Perilipin 2 levels are increased in patients with in-stent neoatherosclerosis: A clue to mechanisms of accelerated plaque formation after drug-eluting stent implantation.

BACKGROUND: Perilipin 2 (PLIN2) is a protein that potentially facilitates atherogenesis in native coronary arteries or arteries with an implanted drug-eluting stent (DES). The aim of the study was to determine PLIN2 protein levels in peripheral monocytes of enrolled subjects and compare them between patients with native coronary artery disease (CAD) and those with an in-stent restenosis (ISR) due to neoatherosclerosis occurring >1 year after DES implantation. METHODS: Forty-two patients were prospectively enrolled in the study in 3:1 fashion and underwent coronary catheterization. Both groups were angiographically matched for CAD burden with respect to the number of diseased vessels. Neoatherosclerosis was determined by intracoronary optical coherence tomography (OCT) among patients with ISR. RESULTS: Patients with ISR due to neoatherosclerosis had significantly higher PLIN2 protein levels in peripheral blood monocytes compared to patients with native CAD (342.47 ±â€¯75.63[SE] versus 119.51 ±â€¯20.95, p < 0.001). PLIN2 protein levels did not significantly differ between unstable and stable disease phenotype (125.59 ±â€¯131.02 vs. 146.14 ±â€¯111.87, p = 0.109). CONCLUSIONS: In this explorative study, PLIN2 protein levels are significantly increased in patients with neoatherosclerosis, irrespective of clinical presentation, implicating that it might play a pathogenetic role in accelerated atherosclerosis after DES implantation. Further larger clinical studies are warranted to confirm these initial findings.

Molecular mechanisms of cardioprotective effects mediated by transplanted cardiac ckit+ cells through the activation of an inflammatory hypoxia-dependent reparative response.

The regenerative effects of cardiac ckit+ stem cells (ckit+CSCs) in acute myocardial infarction (MI) have been studied extensively, but how these cells exert a protective effect on cardiomyocytes is not well known. Growing evidences suggest that in adult stem cells injury triggers inflammatory signaling pathways which control tissue repair and regeneration. Aim of the present study was to determine the mechanisms underlying the cardioprotective effects of ckit+CSCs following transplantation in a murine model of MI. Following isolation and in vitro expansion, cardiac ckit+CSCs were subjected to normoxic and hypoxic conditions and assessed at different time points. These cells adapted to hypoxia as showed by the activation of HIF-1α and the expression of a number of genes, such as VEGF, GLUT1, EPO, HKII and, importantly, of alarmin receptors, such as RAGE, P2X7R, TLR2 and TLR4. Activation of these receptors determined an NFkB-dependent inflammatory and reparative gene response (IRR). Importantly, hypoxic ckit+CSCs increased the secretion of the survival growth factors IGF-1 and HGF. To verify whether activation of the IRR in a hypoxic microenvironment could exert a beneficial effect in vivo, autologous ckit+CSCs were transplanted into mouse heart following MI. Interestingly, transplantation of ckit+CSCs lowered apoptotic rates and induced autophagy in the peri-infarct area; further, it reduced hypertrophy and fibrosis and, most importantly, improved cardiac function. ckit+CSCs are able to adapt to a hypoxic environment and activate an inflammatory and reparative response that could account, at least in part, for a protective effect on stressed cardiomyocytes following transplantation in the infarcted heart.

Granulocyte colony-stimulating factor for the treatment of cardiovascular diseases: An update with a critical appraisal.

Heart failure and acute myocardial infarction are conditions that are associated with high morbidity and mortality. Significant dysfunction of the heart muscle can occur as the consequence of end-stage chronic cardiovascular diseases or acute ischemic events that are marked by large infarction area and significant tissue necrosis. Despite the remarkable improvement of conventional treatments, a substantial proportion of patients still develops severe heart failure that can only be resolved by heart transplantation or mechanical device implantation. Therefore, novel approaches based on stem-cell therapy can directly modify the disease process and alter its prognosis. The ability of the stem-cells to modify and repair the injured myocardium is a challenging but intriguing concept that can potentially replace expensive and invasive methods of treatment that are associated with increased risks and significant financial costs. In that sense, granulocyte colony-stimulating factor (G-CSF) seems as an attractive treatment approach. Based on the series of pre-clinical experiments and a limited amount of clinical data, it was demonstrated that G-CSF agents possess the ability to mobilize stem-cells from bone marrow and induce their differentiation into cardiomyocytes or endothelial cells when brought into contact with injured regions of the myocardium. However, clinical benefits of G-CSF use in damaged myocardium remain unclear and are the topic of expert discussion. The main goal of this review is to present relevant and up-to-date evidence on G-CSF therapy use in pre-clinical models and in humans and to provide a rationale for its potential clinical applications in the future.

Human cardiac progenitor cells with regenerative potential can be isolated and characterized from 3D-electro-anatomic guided endomyocardial biopsies.

AIMS: In the present study, we aimed to develop a percutaneous approach and a reproducible methodology for the isolation and expansion of Cardiac Progenitor Cells (CPCs) from EndoMyocardial Biopsies (EMB) in vivo. Moreover, in an animal model of non-ischemic heart failure (HF), we would like to test whether CPCs obtained by this methodology may engraft the myocardium and differentiate. METHODS AND RESULTS: EMB were obtained using a preformed sheath and a disposable bioptome, advanced via right femoral vein in 12 healthy mini pigs, to the right ventricle. EMB were enzymatically dissociated, cells were expanded and sorted for c-kit. We used 3D-Electro-Anatomic Mapping (3D-EAM) to obtain CPCs from 32 patients affected by non-ischemic cardiomyopathy. The in vivo regenerative potential of CPCs was tested in a rodent model of drug-induced non-ischemic cardiomyopathy. c-kit positive CPCs replicative capacity was assessed in 30 patients. Telomere length averaged 7.4±0.4kbp and telomerase activity was present in all preparations (1.7×105 copies). The in situ hybridization experiments showed that injected human CPCs may acquire a neonatal myocyte phenotype given the expression of the alpha-sarcomeric actin together with the presence of the Alu probe, suggesting a beneficial impact on LV performance. CONCLUSIONS: The success in obtaining CPCs characterized by high regenerative potential, in vitro and in vivo, from EMB indicates that harvesting without thoracotomy in patients affected by either ischemic or non-ischemic cardiomyopathy is feasible. These initial results may potentially expand the future application of CPCs to all patients affected by HF not undergoing surgical procedures.

Duchenne Muscular Dystrophy Myogenic Cells from Urine-Derived Stem Cells Recapitulate the Dystrophin Genotype and Phenotype.

A ready source of autologous myogenic cells is of vital importance for drug screening and functional genetic studies in Duchenne muscular dystrophy (DMD), a rare disease caused by a variety of dystrophin gene mutations. As stem cells (SCs) can be easily and noninvasively obtained from urine specimens, we set out to determine whether they could be myogenically induced and useful in DMD research. To this end, we isolated stem cells from the urine of two healthy donors and from one patient with DMD, and performed surface marker characterization, myogenic differentiation (MyoD), and then transfection with antisense oligoribonucleotides to test for exon skipping and protein restoration. We demonstrated that native urine-derived stem cells express the full-length dystrophin transcript, and that the dystrophin mutation was retained in the cells of the patient with DMD, although the dystrophin protein was detected solely in control cells after myogenic transformation according to the phenotype. Notably, we also showed that treatment with antisense oligoribonucleotide against dystrophin exon 44 induced skipping in both native and MyoD-transformed urine-derived stem cells in DMD, with a therapeutic transcript-reframing effect, as well as visible protein restoration in the latter. Hence MyoD-transformed cells may be a good myogenic model for studying dystrophin gene expression, and native urine stem cells could be used to study the dystrophin transcript, and both diagnostic procedures and splicing modulation therapies in both patients and control subjects, without invasive and costly collection methods. New, bankable bioproducts from urine stem cells, useful for prescreening studies and therapeutic applications alike, are also foreseeable after further, more in-depth characterization.

Growth properties of cardiac stem cells are a novel biomarker of patients' outcome after coronary bypass surgery.

BACKGROUND: The efficacy of bypass surgery in patients with ischemic cardiomyopathy is not easily predictable; preoperative clinical conditions may be similar, but the outcome may differ significantly. We hypothesized that the growth reserve of cardiac stem cells (CSCs) and circulating cytokines promoting CSC activation are critical determinants of ventricular remodeling in this patient population. METHODS AND RESULTS: To document the growth kinetics of CSCs, population-doubling time, telomere length, telomerase activity, and insulin-like growth factor-1 receptor expression were measured in CSCs isolated from 38 patients undergoing bypass surgery. Additionally, the blood levels of insulin-like growth factor-1, hepatocyte growth factor, and vascular endothelial growth factor were evaluated. The variables of CSC growth were expressed as a function of the changes in wall thickness, chamber diameter and volume, ventricular mass-to-chamber volume ratio, and ejection fraction, before and 12 months after surgery. A high correlation was found between indices of CSC function and cardiac anatomy. Negative ventricular remodeling was not observed if CSCs retained a significant growth reserve. The high concentration of insulin-like growth factor-1 systemically pointed to the insulin-like growth factor-1-insulin-like growth factor-1 receptor system as a major player in the adaptive response of the myocardium. hepatocyte growth factor, a mediator of CSC migration, was also high in these patients preoperatively, as was vascular endothelial growth factor, possibly reflecting the vascular growth needed before bypass surgery. Conversely, a decline in CSC growth was coupled with wall thinning, chamber dilation, and depressed ejection fraction. CONCLUSIONS: The telomere-telomerase axis, population-doubling time, and insulin-like growth factor-1 receptor expression in CSCs, together with a high circulating level of insulin-like growth factor-1, represent a novel biomarker able to predict the evolution of ischemic cardiomyopathy following revascularization.