Granulocyte colony-stimulating factor-induced blood stem cell mobilisation in patients with chronic heart failure--Feasibility, safety and effects on exercise tolerance and cardiac function

Role of Autophagy in Granulocyte-Colony Stimulating Factor Induced Anti-Apoptotic Effects in Diabetic Cardiomyopathy

BACKGROUND

We previously, reported that granulocyte-colony stimulating factor (G-CSF) reduces cardiomyocyte apoptosis in diabetic cardiomyopathy. However, the underlying mechanisms are not yet fully understood. Therefore, we investigated whether the mechanisms underlying of the anti-apoptotic effects of G-CSF were associated with autophagy using a rat model of diabetic cardiomyopathy.

METHODS

Diabetic cardiomyopathy was induced in rats through a high-fat diet combined with low-dose streptozotocin and the rats were then treated with G-CSF for 5 days. Rat H9c2 cardiac cells were cultured under high glucose conditions as an in vitro model of diabetic cardiomyopathy. The extent of apoptosis and protein levels related to autophagy (Beclin-1, microtubule-binding protein light chain 3 [LC3]-II/LC3-I ratio, and P62) were determined for both models. Autophagy determination was performed using an Autophagy Detection kit.

RESULTS

G-CSF significantly reduced cardiomyocyte apoptosis in the diabetic myocardium in vivo and led to an increase in Beclin-1 level and the LC3-II/LC3-I ratio, and decreased P62 level. Similarly, G-CSF suppressed apoptosis, increased Beclin-1 level and LC3-II/LC3-I ratio, and decreased P62 level in high glucose-induced H9c2 cardiac cells in vitro. These effects of G-CSF were abrogated by 3-methyladenine, an autophagy inhibitor. In addition, G-CSF significantly increased autophagic flux in vitro.

CONCLUSION

Our results suggest that the anti-apoptotic effect of G-CSF might be significantly associated with the up-regulation of autophagy in diabetic cardiomyopathy.

Role of MicroRNA-34a in Anti-Apoptotic Effects of Granulocyte-Colony Stimulating Factor in Diabetic Cardiomyopathy

BACKGROUND

Recent studies have shown that microRNAs (miRNAs) are involved in the process of cardiomyocyte apoptosis. We have previously reported that granulocyte-colony stimulating factor (G-CSF) ameliorated diastolic dysfunction and attenuated cardiomyocyte apoptosis in a rat model of diabetic cardiomyopathy. In this study, we hypothesized a regulatory role of cardiac miRNAs in the mechanism of the anti-apoptotic effect of G-CSF in a diabetic cardiomyopathy rat model.

METHODS

Rats were given a high-fat diet and low-dose streptozotocin injection and then randomly allocated to receive treatment with either G-CSF or saline. H9c2 rat cardiomyocytes were cultured under a high glucose (HG) condition to induce diabetic cardiomyopathy in vitro. We examined the extent of apoptosis, miRNA expression, and miRNA target genes in the myocardium and H9c2 cells.

RESULTS

G-CSF treatment significantly decreased apoptosis and reduced miR-34a expression in diabetic myocardium and H9c2 cells under the HG condition. G-CSF treatment also significantly increased B-cell lymphoma 2 (Bcl-2) protein expression as a target for miR-34a. In addition, transfection with an miR-34a mimic significantly increased apoptosis and decreased Bcl-2 luciferase activity in H9c2 cells.

CONCLUSION

Our results indicate that G-CSF might have an anti-apoptotic effect through down-regulation of miR-34a in a diabetic cardiomyopathy rat model.

Application of G-CSF in Congestive Heart Failure Treatment

INTRODUCTION

Congestive Heart Failure (CHF) is a disorder in which the heart is unable to supply enough blood for body tissues. Since heart is an adaptable organ, it overcomes this condition by going under remodeling process. Considering cardiac myocytes are capable of proliferation after MI, stimulation of neovascularization as well as their regeneration might serve as a novel target in cardiac remodeling prevention and CHF treatment. Granulocyte Colony-Stimulating Factor (G-CSF), is a hematopoietic cytokine that promotes proliferation and differentiation of neutrophils and is involved in cardiac repair after MI. So far, this is the first review to focus on GCSF as a novel treatment for heart failure.

METHODS

We conducted a search of some databases such as PubMed for articles and reviews published between 2003 and 2017, with different keywords including "G-CSF", "congestive heart failure", "new therapies for CHF", "filgrastim", "in vivo study".

RESULTS

GCSF exerts its beneficial effects on cardiac repair through either stem cell mobilization or direct angiogenesis promotion. All of which are capable of promoting cardiac cell repair.

CONCLUSION

GCSF is a promising target in CHF-therapy by means of cardiac repair and remodeling prevention through multiple mechanisms, which are effective enough to be used in clinical practice.

Granulocyte-colony stimulating factor reduces cardiomyocyte apoptosis and ameliorates diastolic dysfunction in Otsuka Long-Evans Tokushima Fatty rats

BACKGROUND

In recent studies, granulocyte-colony stimulating factor (G-CSF) was shown to improve cardiac function in myocardial infarction and non-ischemic cardiomyopathies. The mechanisms of these beneficial effects of G-CSF in diabetic cardiomyopathy are not yet fully understood. Therefore, we investigated the mechanisms of action of G-CSF on diabetic cardiomyopathy in a rat model of type 2 diabetes.

METHODS

Seventeen-week-old OLETF (Otsuka Long Evans Tokushima Fatty) diabetic rats and LETO (Long Evans Tokushima Otuska) rats were randomized to treatment with 5 days of G-CSF (100 μg/kg/day) or with saline. Cardiac function was evaluated by serial echocardiography performed before and 4 weeks after treatment. We measured expression of the G-CSF receptor (GCSFR) and Bcl-2, as well as the extent of apoptosis in the myocardium.

RESULTS

G-CSF treatment significantly improved cardiac diastolic function in the serial echocardiography assessments. Expression of G-CSFR was down-regulated in the diabetic myocardium (0.03 ± 0.12 % vs. 1 ± 0.15 %, p < 0.05), and its expression was stimulated by G-CSF treatment (0.03 ± 0.12 % vs. 0.42 ± 0.06 %, p < 0.05). In addition, G-CSF treatment increased the expression of Bcl-2 in the diabetic myocardium (0.69 ± 0.06 % vs. 0.26 ± 0.11 %, p < 0.05), consistent with the reduced cardiomyocyte apoptosis (9.38 ± 0.67 % vs. 17.28 ± 2.16 %, p < 0.05).

CONCLUSIONS

Our results suggest that G-CSF might have a cardioprotective effect in diabetic cardiomyopathy through up-regulation of G-CSFR, attenuation of apoptosis by up-regulation of Bcl-2 expression, and glucose-lowering effect. Our findings support the therapeutic potential of G-CSF in diabetic cardiomyopathy.

Safety and feasibility of intramyocardial versus intracoronary delivery of autologous cell therapy in advanced heart failure: the REGENERATE-IHD pilot study

AIM

This study presents an interim safety and feasibility analysis of the REGENERATE-IHD randomized controlled trial, which is examining the safety and efficacy of three different delivery routes of bone marrow-derived stem cells (BMSCs) in patients with ischemic heart failure.

METHODS & RESULTS

The first 58 patients recruited to the REGENERATE-IHD study are included in this interim analysis (pilot). Symptomatic patients with ischemic heart failure were randomized to receive subcutaneous granulocyte colony-stimulating factor or saline injections only; or subcutaneous granulocyte colony-stimulating factor injections followed by intracoronary or intramyocardial injections of BMSCs or serum (control). No significant differences were found in terms of safety and feasibility between the different delivery routes, with no significant difference in procedural complications or major adverse cardiac events. There was a signal towards improved heart failure symptoms in the patients treated with intramyocardial injection of mobilized BMSCs.

CONCLUSION

Peripheral mobilization of BMSCs with or without subsequent direct myocardial delivery appears safe and feasible in patients with chronic ischemic heart failure.

Study of peripheral stem cells mobilization as a treatment line of pediatric dilated cardiomyopathy

BACKGROUND

Mobilizing hematopoietic stem cells may be a promising intervention for the treatment of idiopathic dilated cardiomyopathy (IDCM) in infant and children. So the aim of the work is to evaluate the efficacy of granulocyte-colony stimulating factor (G-CSF) as a therapeutic modality in pediatric IDCM.

METHODS

A randomized clinical trial was conducted on 40 pediatric patients with IDCM. They were subjected to history taking, clinical examination, serum lactate dehydrogenase (LDH), total creatinine phosphokinase (CPK), creatinine phosphokinase isoenzyme B (CK-MB) isoenzyme, and peripheral blood CD34(+) cell assessment before and at day 7 after subcutaneous G-CSF injection for 5 consecutive days. Echocardiography was done before and 1, 3 and 6 months after therapy.

RESULTS

Clinical improvement in the form of regression of patients Modified Ross heart failure (MRHC) classification classes. Increased percentage of CD34(+) mobilized cells from the bone marrow, and significant increase in blood counts especially white blood cells 7 days after G-CSF injection. Significant improvement was found in echocardiographic data evaluating systolic function of the heart [Ejection fraction, Fractional shortening and systolic velocity at mitral annulus (Sm)].

CONCLUSIONS

Administration of G-CSF may be beneficial in improving systolic functions of the heart in pediatric IDCM and more studies with a large number of patients are needed.

Short-term effect of granulocyte colony-stimulating factor in dogs with severe myxomatous mitral valve disease

BACKGROUND

Use of granulocyte colony-stimulating factor (G-CSF) to treat damaged myocardium is a relatively new concept. Clinical beneficial and safety outcomes are still controversial.

OBJECTIVE

The aim of this study was to evaluate recruitment of hematopoietic stem cells and therapeutic efficacy of G-CSF in the treatment of myxomatous mitral valve disease (MMVD) of dogs.

ANIMALS AND METHODS

Thirty client-owned MMVD dogs with clinical signs of heart failure were enrolled in a prospective double-blind, randomized, placebo-controlled study to compare the short-term effect of G-CSF (n = 17) with control group (n = 13) for identical periods. Clinical, hematological, and cardiovascular assessments were performed on days 0, 1, 3, and 7. Follow-up examination was conducted four weeks after the study.

RESULTS

Dogs treated with G-CSF had a significantly elevated white blood cell (WBC) (×10(3)/μL) count at day 3 compared with baseline (from 10.23 ± 4.42 to 42.84 ± 11.84; P = .000). The WBC population was also changed (elevated neutrophils and decreased lymphocytes) and the numbers of CD34+ cells in the peripheral blood were also increased at day 3. However, the results of clinical, laboratory, and echocardiographic assessments did not differ significantly between the G-CSF treatment and control groups after four weeks.

CONCLUSIONS

G-CSF administration elevated the peripheral WBC count, especially neutrophils, and recruited hematopoietic stem cells. However, positive effects of G-CSF on cardiac function were not detected during short-term monitoring.

Granulocyte colony stimulating factor therapy for acute myocardial infarction

BACKGROUND

Acute myocardial infarction (AMI) is the leading cause of death in developed countries, and current treatment modalities have failed to regenerate the dead myocardium resulting from the ischemic damage. Stem cells have the potential to regenerate the damaged myocardium. These cells can be mobilized from the bone marrow by factors such as granulocyte colony stimulating factor (G-CSF).

OBJECTIVES

To assess the effects of stem cell mobilization following granulocyte colony stimulating factor therapy in patients with acute myocardial infarction.

SEARCH METHODS

We searched CENTRAL (The Cochrane Library Issue 4, 2010), MEDLINE (1950 to November week 3, 2010), EMBASE (1980 to 2010 week 48), BIOSIS Previews (1969 to 30 November 2010), ISI Science Citation Index Expanded (1970 to 4 December 2010) and ISI Conference Proceedings Citation Index - Science (1990 to 4 December 2010). We also checked reference lists of articles.

SELECTION CRITERIA

We included randomized controlled trials including participants with a clinical diagnosis of AMI who were randomly allocated to the subcutaneous administration of G-CSF through a daily dose of 2.5, 5 or 10 microgram/kg for four to six days or placebo. No age or other restrictions were applied for the selection of patients.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials, assessed trials for eligibility and methodological quality, and extracted data regarding the clinical efficacy and adverse outcomes. Disagreements were resolved by the third author.

MAIN RESULTS

We included seven trials reported in 30 references in the review (354 participants). In all trials, G-CSF was compared with placebo preparations. Dosage of G-CSF varied among studies, ranging from 2.5 to 10 microgram/kg/day. Regarding overall risk of bias, data regarding the generation of randomization sequence and incomplete outcome data were at a low risk of bias; however, data regarding binding of personnel were not conclusive. The rate of mortality was not different between the two groups (RR 0.64, 95% CI 0.15 to 2.80, P = 0.55). Regarding safety, the limited amount of evidence is inadequate to reach any conclusions regarding the safety of G-CSF therapy. Moreover, the results did not show any beneficial effects of G-CSF in patients with AMI regarding left ventricular function parameters, including left ventricular ejection fraction (RR 3.41, 95% CI -0.61 to 7.44, P = 0.1), end systolic volume (RR -1.35, 95% CI -4.68 to 1.99, P = 0.43) and end diastolic volume (RR -4.08, 95% CI -8.28 to 0.12, P = 0.06). It should also be noted that the study was limited since the trials included lacked long enough follow up durations.

AUTHORS' CONCLUSIONS

Limited evidence from small trials suggested a lack of benefit of G-CSF therapy in patients with AMI. Since data of the risk of bias regarding blinding of personnel were not conclusive, larger RCTs with appropriate power calculations and longer follow up durations are required in order to address current uncertainties regarding the clinical efficacy and therapy-related adverse events of G-CSF treatment.

Therapeutic role of mobilized bone marrow cells in children with nonischemic dilated cardiomyopathy

Dilated cardiomyopathy is an important cause of congestive cardiac failure in infants and children. Mobilizing hematopoietic progenitor cells is a promising intervention to this deadly disease. Aim. Evaluate granulocyte colony stimulating factor (GCSF) as therapeutic modality in children with idiopathic dilated cardiomyopathy (IDCM). Subjects and Methods. This case-control prospective study was conducted on 20 children with IDCM following up at Cardiology Clinic Children's Hospital, Ain Shams University (group 1) who were compared to another 10 age-, sex-, duration-of-illness-, and systolic-function-matched children with IDCM as control (group 2). They were subjected to history taking, clinical examination, echocardiography, and peripheral blood CD34+ cell assessment before and one week after GCSF intake for 5 consecutive days (by group 1 but not group 2). Results. A significant improvement in echocardiographic data and CD34+-T-cell increase was found in group 1 one week after GCSF intake and for the next 6 months CD34+ T cells percentage of change showed no significant correlation with the that of the left ventricular dimensions and systolic function. Conclusion. Administration of GCSF to children with IDCM resulted in clinical and echocardiographic improvement not correlated to mobilized CD34+ T cells, implying involvement of additional mechanisms over simple stem cell mobilization.

Acute effects of granulocyte colony-stimulating factor on early ventricular arrhythmias after coronary occlusion in rats

Objectives:

To evaluate the acute effects of colony-stimulating factor (G-CSF) on ventricular arrhythmias after coronary occlusion in rats.

Materials and Methods:

Male Wistar rats (10 weeks) received G-CSF (100 μg.kg^-1) or vehicle. Thirty minutes later, animals were infarcted by coronary occlusion under artificial respiration. Electrocardiogram was monitored for 30 min to evaluate ventricular arrhythmias.

Results:

G-CSF treatment reduced the number of premature ventricular beats and the number and duration of ventricular tachycardia. The incidence of ventricular fibrillation was significantly reduced by G-CSF (MI-Cont: 11.2 ± 2.4 vs. MI-GCSF: 5.4 ± 1 events; P < 0.05). However, total duration of ventricular fibrillation was not altered (MI-Cont: 84 ± 16 vs. MI-GCSF: 76 ± 13 sec).

Conclusions:

Acute administration of G-CSF before coronary ligature in rats reduces the incidence of ventricular premature beats and ventricular tachycardia, suggesting a possible direct electrophysiological effect of this cytokine independently of its genomic effects. However, the data suggest that G-CSF treatment may affect the spontaneous recovery from ventricular fibrillation. Acute G-CSF administration acts directly on cardiac electrophysiology, different from chronic treatment.

Biomarkers of inflammation, immunosuppression and stress with active disease are revealed by metabolomic profiling of tuberculosis patients

Although tuberculosis (TB) causes more deaths than any other pathogen, most infected individuals harbor the pathogen without signs of disease. We explored the metabolome of >400 small molecules in serum of uninfected individuals, latently infected healthy individuals and patients with active TB. We identified changes in amino acid, lipid and nucleotide metabolism pathways, providing evidence for anti-inflammatory metabolomic changes in TB. Metabolic profiles indicate increased activity of indoleamine 2,3 dioxygenase 1 (IDO1), decreased phospholipase activity, increased abundance of adenosine metabolism products, as well as indicators of fibrotic lesions in active disease as compared to latent infection. Consistent with our predictions, we experimentally demonstrate TB-induced IDO1 activity. Furthermore, we demonstrate a link between metabolic profiles and cytokine signaling. Finally, we show that 20 metabolites are sufficient for robust discrimination of TB patients from healthy individuals. Our results provide specific insights into the biology of TB and pave the way for the rational development of metabolic biomarkers for TB.

Limitations of the MRL mouse as a model for cardiac regeneration

OBJECTIVE

Myocardial repair following injury in mammals is restricted such that damaged areas are replaced by scar tissue, impairing cardiac function. MRL mice exhibit exceptional regenerative healing in an ear punch wound model. Some myocardial repair with restoration of heart function has also been reported following cryoinjury. Increased cardiomyocyte proliferation and a foetal liver stem cell population were implicated. We investigated molecular mechanisms facilitating myocardial repair in MRL mice to identify potential therapeutic targets in non-regenerative species.

METHODS

Expressions of specific cell-cycle regulators that might account for regeneration (CDKs 1, 2, 4 and 6; cyclins A, E, D1 and B1; p21, p27 and E2F5) were compared by immunoblotting in MRL and control C57BL/6 ventricles during development. Flow cytometry was used to investigate stem cell populations in livers from foetal mice, and infarct sizes were compared in coronary artery-ligated and sham-treated MRL and C57BL/6 adult mice.

KEY FINDINGS

No differences in the expressions of cell cycle regulators were observed between the two strains. Expressions of CD34+Sca1+ckit-, CD34+Sca1+ckit+ and CD34+Sca1-ckit+ increased in livers from C57BL/6 vs MRL mice. No differences were observed in infarct sizes, levels of fibrosis, Ki67 staining or cardiac function between MRL and C57BL/6 mice.

CONCLUSIONS

No intrinsic differences were observed in cell cycle control molecules or stem cell populations between MRL and control C57BL mouse hearts. Pathophysiologically relevant ischaemic injury is not repaired more efficiently in MRL myocardium, questioning the use of the MRL mouse as a reliable model for cardiac regeneration in response to pathophysiologically relevant forms of injury.

Regression of cardiac hypertrophy by granulocyte colony-stimulating factor-stimulated interleukin-1β synthesis

AIMS

Aortic stenosis causes cardiac hypertrophy and fibrosis, which often persists despite pressure unloading after aortic valve replacement. The persistence of myocardial fibrosis in particular leads to impaired cardiac function and increased mortality. We investigated whether granulocyte colony-stimulating factor (G-CSF) beneficially influences cardiac remodelling after pressure unloading.

METHODS AND RESULTS

Left ventricular hypertrophy was induced by transverse aortic constriction in C57bl6 mice followed by debanding after 8 weeks. This model closely mimics aortic stenosis and subsequent aortic valve replacement. After debanding, mice were treated with either G-CSF or saline injection. Granulocyte colony-stimulating factor treatment significantly improved systolic (ejection fraction 70.48 ± 1.17 vs. 58.41 ± 1.56%, P < 0.001) and diastolic (E/E' 26.0 ± 1.0 vs. 32.6 ± 0.8, P < 0.05) function. Furthermore, cardiac fibrosis was significantly reduced in G-CSF-treated mice (collagen-I area fraction 7.96 ± 0.47 vs. 11.64 ± 1.22%, P < 0.05; collagen-III area fraction 10.73 ± 0.99 vs. 18.46 ± 0.71%, P < 0.001). Direct effects of G-CSF on cardiac fibroblasts or a relevant transdifferentiation of mobilized bone marrow cells could be excluded. However, a considerable infiltration of neutrophils was observed in G-CSF-treated mice. This sterile inflammation was accompanied by a selective release of interleukin-1 β (IL-1β) in the absence of other proinflammatory cytokines. In vitro experiments confirmed an increased expression of IL-1β in neutrophils after G-CSF treatment. Interleukin-1β directly induced the expression of the gelatinases matrix metalloproteinase-2 (MMP-2) and MMP-9 in cardiac fibroblasts thereby providing the regression of cardiac fibrosis.

CONCLUSION

Granulocyte colony-stimulating factor treatment improves the cardiac function and leads to the regression of myocardial fibrosis after pressure unloading. These findings reveal a previously unknown mechanism of fibrosis regression. Granulocyte colony-stimulating factor might be a potential pharmacological treatment approach for patients suffering from congestive heart failure after aortic valve replacement, although further basic research and clinical trials are required in order to prove beneficial effects of G-CSF in the human organism.

The Bone Marrow Derived Adult Stem Cells for Dilated Cardiomyopathy (REGENERATE-DCM) trial: study design

The field of autologous stem/progenitor cell therapy for cardiovascular diseases has moved rapidly from bench to bedside. In particular, a small number of pilot studies have demonstrated the safety and efficacy of this treatment in dilated cardiomyopathy (DCM), but this has to be validated in large randomized trials. Here we introduce the Bone Marrow Derived Adult Stem Cells for Dilated Cardiomyopathy (REGENERATE-DCM) trial, which to our knowledge, is the first randomized, double-blind, placebo-controlled trial worldwide to investigate the role of granulocyte-colony stimulating factor and autologous bone marrow-derived stem/progenitor cells to improve cardiac function in patients with DCM.

Hematopoietic cytokines for cardiac repair: mobilization of bone marrow cells and beyond

Hematopoietic cytokines, traditionally known to influence cellular proliferation, differentiation, maturation, and lineage commitment in the bone marrow, include granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor, stem cell factor, Flt-3 ligand, and erythropoietin among others. Emerging evidence suggests that these cytokines also exert multifarious biological effects on diverse nonhematopoietic organs and tissues. Although the precise mechanisms remain unclear, numerous studies in animal models of myocardial infarction (MI) and heart failure indicate that hematopoietic cytokines confer potent cardiovascular benefits, possibly through mobilization and subsequent homing of bone marrow-derived cells into the infarcted heart with consequent induction of myocardial repair involving multifarious mechanisms. In addition, these cytokines are also known to exert direct cytoprotective effects. However, results from small-scale clinical trials of G-CSF therapy as a single agent after acute MI have been discordant and largely disappointing. It is likely that cardiac repair following cytokine therapy depends on a number of known and unknown variables, and further experimental and clinical studies are certainly warranted to accurately determine the true therapeutic potential of such therapy. In this review, we discuss the biological features of several key hematopoietic cytokines and present the basic and clinical evidence pertaining to cardiac repair with hematopoietic cytokine therapy.

Impaired cardiac reserve and severely diminished skeletal muscle O₂ utilization mediate exercise intolerance in Barth syndrome

Barth syndrome (BTHS) is a mitochondrial myopathy characterized by reports of exercise intolerance. We sought to determine if 1) BTHS leads to abnormalities of skeletal muscle O(2) extraction/utilization and 2) exercise intolerance in BTHS is related to impaired O(2) extraction/utilization, impaired cardiac function, or both. Participants with BTHS (age: 17 ± 5 yr, n = 15) and control participants (age: 13 ± 4 yr, n = 9) underwent graded exercise testing on a cycle ergometer with continuous ECG and metabolic measurements. Echocardiography was performed at rest and at peak exercise. Near-infrared spectroscopy of the vastus lateralis muscle was continuously recorded for measurements of skeletal muscle O(2) extraction. Adjusting for age, peak O(2) consumption (16.5 ± 4.0 vs. 39.5 ± 12.3 ml·kg(-1)·min(-1), P < 0.001) and peak work rate (58 ± 19 vs. 166 ± 60 W, P < 0.001) were significantly lower in BTHS than control participants. The percent increase from rest to peak exercise in ejection fraction (BTHS: 3 ± 10 vs. control: 19 ± 4%, P < 0.01) was blunted in BTHS compared with control participants. The muscle tissue O(2) saturation change from rest to peak exercise was paradoxically opposite (BTHS: 8 ± 16 vs. control: -5 ± 9, P < 0.01), and the deoxyhemoglobin change was blunted (BTHS: 0 ± 12 vs. control: 10 ± 8, P < 0.09) in BTHS compared with control participants, indicating impaired skeletal muscle extraction in BTHS. In conclusion, severe exercise intolerance in BTHS is due to both cardiac and skeletal muscle impairments that are consistent with cardiac and skeletal mitochondrial myopathy. These findings provide further insight to the pathophysiology of BTHS.

Granulocyte-colony-stimulating Factor for Acute Ischemic Stroke: A Randomized Controlled Trial (STEMTHER)

Granulocyte-colony-stimulating factor (G-CSF) functions both as a neuroprotectant and a stimulator of autologous bone marrow stem cell release. Therefore, administration of G-CSF should improve the outcome of stroke. Here, we examine the safety of using G-CSF to treat acute ischemic stroke using a randomized controlled trial involving 20 adult patients presenting with ischemia in the carotid region within 48 h of onset. The experimental group (n = 10) received subcutaneous G-CSF injections (10 mg kg(-1) day(-1)) in addition to conventional therapy for 5 days. The primary outcome was motor function as measured by the modified Rankin Scale 180 days post-stroke. Safety was evaluated according to the frequency of hemorrhagic transformation of infarctions and serious adverse events. Only six patients in the experimental group completed full course of treatment, while four patients (three in the control and one in the experimental group) were lost to follow-up. We found the experimental and control groups did not differ significantly in either neurological impairment or degree of disability/dependence at 180 days post-stroke. We conclude that while adding G-CSF (10 mg kg(-1) day(-1)) to acute ischemic stroke therapy for 5 days is safe, its efficacy remains unproven.

The mobilization of autologous bone marrow stem cells in the treatment of heart failure with Chinese medicine

Heart failure (HF) is a severe heart disease. The use of autologous bone marrow stem cells (BMCs) mobilization in the treatment of HF has been a hot topic to research both in Western medicine and Chinese medicine (CM). There are many clinical trials and experiments on study of BMCs mobilization for HF therapy, including integrative medicine. The effect of BMCs mobilization is favorable for cardiac repair, while some advantages of CM support the advanced study of its application in BMCs mobilization to treat HF. In addition, with mechanisms of autologous BMCs mobilization for the treatment of HF that will be revealed in the future, especially stem cells niches, integrative medicine would play an important role in this clinical thought of therapy model gradually. Simultaneously, CM should adapt the new approaches of stem cells progresses on HF treatment as holding characteristics of itself.

Granulocyte colony-stimulating factor increases sympathetic reinnervation and the arrhythmogenic response to programmed electrical stimulation after myocardial infarction in rats

Granulocyte colony-stimulating factor (G-CSF) has been used for the repair of infarcted myocardium, but concerns have been raised regarding its proarrhythmic potential. We analyzed the influence of G-CSF treatment on sympathetic nerve remodeling and the expression of nestin in a rat model of experimental myocardial infarction (MI). Twenty-four hours after ligation of the anterior descending artery, male Wistar rats were randomized to receive either saline (MI/C) or G-CSF (MI/G) for 5 days. At 56 days after infarction, MI/G rats had a significantly higher left ventricular ejection fraction accompanied by a significant decrease in the left ventricular end-diastolic dimension than the MI/C group. Myocardial norepinephrine levels revealed a significant elevation in MI/G rats in the border zone compared with MI/C rats. Immunohistochemical analysis for tyrosine hydroxylase, growth-associated protein 43, and neurofilament also confirmed the changes of myocardial norepinephrine. At 5 days after infarction, MI/G rats had increased numbers of tissue-infiltrated CD34(+) cells, although a similar increase in circulating neutrophil counts between sham-operated rats treated with G-CSF and MI/G rats was observed. Compared with MI/C rats, MI/G rats showed an increase of nestin and nerve growth factor expression, as assessed by protein expression and mRNA levels. The arrhythmia scores during programmed stimulation were significantly higher in MI/G rats than in MI/C rats, suggesting proarrhythmic potential. These findings suggest that, although G-CSF administration after infarction improved myocardial function, it resulted in the activation of nestin and nerve growth factor expression and increased sympathetic reinnervation, which may increase the arrhythmogenic response to programmed electrical stimulation.

Cytokines and myocardial regeneration: a novel treatment option for acute myocardial infarction

The regenerative capacity of the myocardium and its blood vessels has now been well demonstrated. The cytokines granulocyte colony-stimulating factor, erythropoietin, and stem cell factor may play a role in helping to stimulate cell regeneration under normal physiologic conditions and in patients with myocardial injury. After an ischemic insult, cytokines are released into the peripheral circulation and signal for the mobilization of stem cells. In experimental cardiac injury models, the addition of cytokines has been shown to improve myocardial function with and without the concurrent use of stem cell therapy. Preliminary studies in humans using cytokine therapy alone for treating myocardial infarction have been disappointing. Future studies in patients with myocardial injury need to examine the use of various combinations of cytokines, with and without the addition of intravascular stem cell infusions or direct stem cell injections.

Autologous bone marrow-derived stem cells for ischemic heart failure: REGENERATE-IHD trial

The field of autologous stem/progenitor cell transplantation for cardiovascular diseases has moved rapidly from basic science research to clinical trials. To date, only a handful of pilot studies have reported the use of this novel strategy for heart failure patients. Most of these studies have demonstrated encouraging safety and efficacy data. However, this will need to be validated in large, randomized trials. Here, we introduce the ongoing REGENERATE-IHD trial, which is the largest randomized, placebo-controlled trial in the UK investigating the use of granulocyte-colony stimulating factor and autologous bone marrow-derived stem/progenitor cells to improve cardiac function and symptoms in heart failure patients.

Improvement of cardiac function after granulocyte-colony stimulating factor-mobilized peripheral blood mononuclear cell implantation in a patient with non-ischemic dilated cardiomyopathy associated with thromboangiitis obliterans

Cardiac involvement is a rare complication with thromboangiitis obliterans (TAO). We report a 29-year-old man with TAO accompanied with non-ischemic dilated cardiomyopathy. He had no history of heart disease, but echocardiogram demonstrated diffuse hypokinesis and dilated left ventricle. Coronary angiography revealed no organic stenotic lesion. For limb salvage, he was treated with granulocyte-colony stimulating factor (G-CSF)-mobilized peripheral blood mononuclear cell (PBMNC) implantation on his right leg. Not only ischemic leg symptoms, but also plasma level of BNP and (123)I-metaiodobenzylguanidine scintigraphic parameters improved after 24 weeks. G-CSF-mobilized PBMNC implantation could be an effective approach to treating non-ischemic cardiomyopathy.

Granulocyte colony-stimulating factor administration: adverse events

Recombinant human granulocyte colony-stimulating factor (G-CSF) has been in clinical use for approximately 2 decades. In healthy donors, it has been used to mobilize peripheral blood progenitor cells for hematopoietic stem cell transplantation and granulocytes for apheresis collection. In patients, it has been used to decrease the duration of neutropenia after chemotherapy and to offset the neutropenia due to myelodysplasia, acquired immunodeficiency syndrome, and genetic disorders of granulocyte production. As the number of uses of G-CSF in clinical practice grows, more side effects of this generally safe pharmaceutical agent are being recognized. Our objective in this article is to provide an in-depth review of the reported adverse events associated with the use of G-CSF.

Drugs, gene transfer, signaling factors: a bench to bedside approach to myocardial stem cell therapy

In the past few years, the dogma that the heart is a terminally differentiated organ has been challenged. Evidence from preclinical investigations emerged that there are cells, even in the heart itself, that may be able to restore impaired cardiac function after myocardial infarction. Although the exact mechanisms by which the infarcted heart can be repaired by stem cells are not yet fully defined, there is a new optimism among cardiologists that this treatment will prove successful in addressing the cause of heart failure after myocardial infarction-myocyte loss. Despite the promising preliminary data of human myocardial stem cell trials, scientists have also focused on the possibility of enhancing the underlying mechanisms of stem cell repair to gain healthier myocardial tissue. Attempts to induce neo-angiogenesis by transfecting stem cells with signaling factors (such as VEGF), to raise the number of endothelial progenitor cells with medical treatments (such as statins), to transfect stem cells with heat shock protein 70 (as a cardioprotective agent against ischemia) and to enhance the healing process after myocardial infarction with the use of various forms of stimulating factors (G-CSF, SCF, GM-CSF) have been made with notable results. In this article, we summarize the evidence from preclinical and clinical myocardial stem cell studies that have addressed the possibility of enhancing the regenerative capacity of cells used after myocardial infarction.

Cardiac repair--fact or fancy?

Patients with ischemic cardiomyopathy have a poor prognosis despite all pharmacological, interventional and surgical treatment modalities currently applied. Heart transplantation remains the ideal treatment for this group of patients but the scarcity of donors hinders its widespread application. The autologous transplantation of stem cells (SCs) for cardiac repair is emerging as a new therapy for patients with myocardial dysfunction early after an acute infarction or ischemic cardiomyopathy. The rationale of this novel method is the enhancement of the repair mechanisms achieved by tissue-specific and circulating stem/progenitor cells. SCs assist naturally occurring myocardial repair by contributing to increased myocardial perfusion and contractile performance especially in the setting of acute myocardial infarction (AMI), but also in patients with chronic ischemic heart failure and advanced, diffuse coronary artery disease. The exact mechanism of their action has not been fully elucidated. Few studies continue to suggest a formation of few new contractile tissue. The majority if investigators believe that these cells do not persist long in the myocardium but that they secrete vascular growth and other cardioprotective factors.

Actions and therapeutic potential of G-CSF and GM-CSF in cardiovascular disease

Despite their names, the cytokines granulocyte- and granulocyte-macrophage-colony stimulating factor (G-CSF and GM-CSF respectively) have actions far beyond simply stimulating the proliferation of neutrophil and monocyte lineage cells. A comprehensive body of evidence now exists demonstrating that G-CSF and GM-CSF effectively mobilize bone-marrow-derived progenitor cells into the peripheral circulation. These mobilized progenitor cells can be conveniently harvested for use in reconstituting bone marrow by transplantation after myelo-ablative treatment of hematological malignancies. In addition, much evidence has recently emerged to suggest that these cytokines may have multiple direct and indirect beneficial cardiovascular effects--including neovascularization of ischemic myocardium and reducing the extent of myocardial damage after infarction. Based on this knowledge and a strong safety record in hematological applications, a number of early clinical trials have evaluated the use of G-CSF or GM-CSF in patients with both acute and chronic myocardial ischemia. Although the interpretation of these trials is complicated by heterogeneity in study design, small patient numbers and methodological concerns related to appropriate selection and blinding of patients, the results of ongoing larger phase II/III trials should soon be available to determine if these agents will be useful additions to the cardiovascular armamentarium.

G-CSF does not improve systolic function in a rat model of acute myocardial infarction

OBJECTIVE

Granulocyte colony-stimulating factor (G-CSF) has been reported to improve cardiac performance by increasing the number of bone marrow stem cell in the peripheral circulation. The aim of this study was to investigate the impact of G-CSF administration on cardiac function in a rat model of acute myocardial infarction.

METHODS

Recombinant human G-CSF (Filgrastim, 100 microg/kg, sc) twice a day during seven consecutive days (G-CSF group, n=13) or vehicle (control group, n=10) was administrated three hours after left anterior coronary artery ligation. Cardiac performance was evaluated 19-21 days after myocardial infarction by electro- and echocardiography, hemodynamic and treadmill exercise test.

RESULTS

Both infarcted groups exhibit impaired cardiac function compared to sham-operated rats. Moreover, all cardiac functional parameters were not statistically different between G-CSF and infarcted group at resting conditions as well as after treadmill exercise stress test. There was no sign of cardiac regeneration and infarct size was not different on histological analysis between groups.

CONCLUSIONS

These data clearly shows that G-CSF treatment was unable to prevent cardiac remodeling or to improve cardiovascular function in a rat model of acute myocardial infarction, by permanent LAD ligation, despite bone marrow stem cell mobilization.

Potential Hazards and Technical Considerations Associated With Myocardial Cell Transplantation Protocols for Ischemic Myocardial Syndrome

Cell transplantation has recently emerged as a promising therapeutic approach to ischemic cardiomyopathy syndromes. Clinical studies suggest important benefits, including improved myocardial perfusion and function. The safety profile so far seems to be high overall, although the technique may harbor several adverse effects, such as ventricular arrhythmia, acceleration of atherosclerosis or restenosis, and induction of ischemic events. Multiple factors may affect the safety of cell infusion into the diseased heart, including the mode of delivery, the type of cells injected, compound characterization, and the heart status, function, and arrhythmogenic potential. Also, any adjunctive treatment used to enhance cellular homing and/or transdifferentiation increases the likelihood of unexpected local or systemic toxicity or side effects. In the present review, we discuss the potential hazards of this novel treatment and its relationship to technical considerations.

Rapid succession of peripheral blood progenitor cell mobilization cycles in patients with chronic heart failure: effects on the hematopoietic system

BACKGROUND

Circulating hematopoietic peripheral blood progenitor cells (PBPCs) may contribute to the regeneration of nonhematopoietic organs. An increase in circulating PBPC numbers may enhance this process. Therefore, an exploratory trial of repeated PBPC mobilization in patients with chronic heart failure was conducted. The safety and cardiovascular efficacy data have been described elsewhere. In the hematopoietic system, the trial offered an opportunity to study several new aspects of granulocyte-colony-stimulating factor (G-CSF) action.

STUDY DESIGN AND METHODS

Fourteen male patients with chronic heart failure were treated successively with G-CSF (four 10-day treatment periods interrupted by treatment-free intervals of equal length; daily dose adjustment to maintain a white blood cell [WBC] count of 45 x 10(9)-50 x 10(9)/L).

RESULTS

G-CSF induced a rapid increase in cells of all WBC lineages with return to levels equal to (neutrophilic, eosinophilic, and basophilic granulocytes) or lower than those before treatment (monocytes, lymphocytes) during the treatment-free intervals. Red cell counts remained unchanged, but platelet counts decreased followed by rebound thrombocytosis. The extent of CD34+ cell mobilization was highly variable. For each patient, the changes induced were identical through all cycles, but the G-CSF dose required in the first cycle was significantly higher than in subsequent cycles. In the cohort of patients, an inverse correlation was observed between the WBC level reached and the dose of G-CSF administered.

CONCLUSIONS

Rapid alternation between PBPC mobilization and recovery periods is feasible, with identical alterations in all treatment cycles. G-CSF responsiveness varies among patients and is increased by pretreatment with G-CSF.

Mesenchymal stem cells transmigrate over the endothelial barrier

Mesenchymal stem cells (MSCs) seem to be a useful tool for cellular therapy in injured tissues, e.g. myocardial infarction or cardiomyopathies resulting in heart failure. For therapeutic approaches it is crucial that MSCs cross the endothelial barrier especially in intravascular or rather intracoronary application. Until today little is known about MSCs transmigrating across the endothelium. We performed co-culture experiments of MSCs on an endothelial monolayer to analyse direct interactions. An increasing flattened morphology of the MSCs was followed by a total integration into the monolayer after 2h. We repeated these experiments in isolated heart perfusions with gold-labelled MSCs. Using electron microscopy we detected MSCs exhibited direct cell-cell contacts. Tight junctions between the endothelial cells became abolished resulting in a distinct split between the cells. MSCs developed tight cell-cell contacts and became integrated into the endothelial wall of the capillary vessel. Finally, using confocal laser scanning microscopy, we assessed the ability of the MSCs to fully pass the endothelial barrier. Within the first 30 min, 30+/-8% of MSCs transmigrated, increasing to about half at 60 min (50+/-8%), whereas after 120 min the rate remained nearly unchanged (53+/-10%). This work demonstrates the capability of MSCs for transendothelial migration. Moreover we showed that the vast majority of MSCs migrated within 30 min, an important finding for the exposure times in clinical settings.