Biodistribution of bone marrow mononuclear cells in chronic chagasic cardiomyopathy after intracoronary injection

Cell-Based Therapies for Heart Failure

Heart failure has reached epidemic proportions with the advances in cardiovascular therapies for ischemic heart diseases and the progressive aging of the world population. Efficient pharmacological therapies are available for treating heart failure, but unfortunately, even with optimized therapy, prognosis is often poor. Their last therapeutic option is, therefore, a heart transplantation with limited organ supply and complications related to immunosuppression. In this setting, cell therapies have emerged as an alternative. Many clinical trials have now been performed using different cell types and injection routes. In this perspective, we will analyze the results of such trials and discuss future perspectives for cell therapies as an efficacious treatment of heart failure.

Autologous bone marrow-derived mononuclear cell therapy in three patients with severe asthma

BACKGROUND

Despite recent advances in understanding its pathophysiology and development of novel therapies, asthma remains a serious public health issue worldwide. Combination therapy with inhaled corticosteroids and long-acting β₂-adrenoceptor agonists results in disease control for many patients, but those who exhibit severe asthma are often unresponsive to conventional treatment, experiencing worse quality of life, frequent exacerbations, and increasing healthcare costs. Bone marrow-derived mononuclear cell (BMMC) transplantation has been shown to reduce airway inflammation and remodeling and improve lung function in experimental models of allergic asthma.

METHODS

This is a case series of three patients who presented severe asthma, unresponsive to conventional therapy and omalizumab. They received a single intravenous dose of autologous BMMCs (2 × 10⁷) and were periodically evaluated for 1 year after the procedure. Endpoint assessments included physical examination, quality of life questionnaires, imaging (computed tomography, single-photon emission computed tomography, and ventilation/perfusion scan), lung function tests, and a 6-min walk test.

RESULTS

All patients completed the follow-up protocol. No serious adverse events attributable to BMMC transplantation were observed during or after the procedure. Lung function remained stable throughout. A slight increase in ventilation of the right lung was observed on day 120 after BMMC transplantation in one patient. All three patients reported improvement in quality of life in the early post-procedure course.

CONCLUSIONS

This paper described for the first time the effects of BMMC therapy in patients with severe asthma, providing a basis for subsequent trials to assess the efficacy of this therapy.

Circulatory support and stem cell therapy in the management of advanced heart failure: a concise review of available evidence

Stem cell therapy utilizing bone marrow mononuclear cells (BMC's) is a potential strategy to treat heart failure patients with improvement in symptom profile and cardiac function. We describe a rationale for concurrent BMC and left ventricular assist device therapy in selected heart failure patients. This combination therapy has demonstrated improved myocardial perfusion and cardiac function in patients with advanced ischemic cardiomyopathy. Moreover, preclinical data support improved cell retention with left ventricular unloading. The beneficial effects of BMC's are likely through a paracrine mechanism initiating a 'cardiac-repair' process. Combination therapy of BMC's and a left ventricular assist device may exhibit a synergistic effect with improved engraftment of BMC's through left ventricular unloading.

Concise Review: Quantitative Detection and Modeling the In Vivo Kinetics of Therapeutic Mesenchymal Stem/Stromal Cells

Mesenchymal stem/stromal cells (MSCs) present a promising tool in cell‐based therapy for treatment of various diseases. Currently, optimization of treatment protocols in clinical studies is complicated by the variations in cell dosing, diverse methods used to deliver MSCs, and the variety of methods used for tracking MSCs in vivo. Most studies use a dose escalation approach, and attempt to correlate efficacy with total cell dose. Optimization could be accelerated through specific understanding of MSC distribution in vivo, long‐term viability, as well as their biological fate. While it is not possible to quantitatively detect MSCs in most targeted organs over long time periods after systemic administration in clinical trials, it is increasingly possible to apply pharmacokinetic modeling to predict their distribution and persistence. This Review outlines current understanding of the in vivo kinetics of exogenously administered MSCs, provides a critical analysis of the methods used for quantitative MSC detection in these studies, and discusses the application of pharmacokinetic modeling to these data. Finally, we provide insights on and perspectives for future development of effective therapeutic strategies using pharmacokinetic modeling to maximize MSC therapy and minimize potential side effects. Stem Cells Translational Medicine2018;7:78–86

Cell therapies for Chagas disease

In this review of cell therapies in Chagas disease, we cover aspects related to the disease, its treatment and world demographics, before proceeding to describe the preclinical and clinical trials performed using cell therapies in the search for an alternative therapy for the most severe and lethal form of this disease, chronic chagasic cardiomyopathy.

Molecular imaging in stem cell-based therapies of cardiac diseases

In the past 15years, despite that regenerative medicine has shown great potential for cardiovascular diseases, the outcome and safety of stem cell transplantation has shown controversial results in the published literature. Medical imaging might be useful for monitoring and quantifying transplanted cells within the heart and to serially characterize the effects of stem cell therapy of the myocardium. From the multiple available noninvasive imaging techniques, magnetic resonance imaging and nuclear imaging by positron (PET) or single photon emission computer tomography (SPECT) are the most used clinical approaches to follow the fate of transplanted stem cells in vivo. In this article, we provide a review on the role of different noninvasive imaging modalities and discuss their advantages and disadvantages. We focus on the different in-vivo labeling and reporter gene imaging strategies for stem cell tracking as well as the concept and reliability to use imaging parameters as noninvasive surrogate endpoints for the evaluation of the post-therapeutic outcome.

Multimodality molecular imaging in cardiac regenerative therapy

Stem cell therapy holds great promise for the repair and regeneration of damaged myocardium. Disappointing results from recent large-scale randomized trials using adult stem cells, however, have led some to question the efficacy of this new therapeutic. Because most clinical stem cell trials have not incorporated molecular imaging to track cell fate, it may be premature to abandon this approach. Herein, we will review how multimodality imaging can be incorporated into cardiac regenerative therapy to facilitate the translation of stem cell therapy.

Tracking stem cells with superparamagnetic iron oxide nanoparticles: perspectives and considerations

Superparamagnetic iron oxide nanoparticles (SPIONs) have been used for diagnoses in biomedical applications, due to their unique properties and their apparent safety for humans. In general, SPIONs do not seem to produce cell damage, although their long-term in vivo effects continue to be investigated. The possibility of efficiently labeling cells with these magnetic nanoparticles has stimulated their use to noninvasively track cells by magnetic resonance imaging after transplantation. SPIONs are attracting increasing attention and are one of the preferred methods for cell labeling and tracking in preclinical and clinical studies. For clinical protocol approval of magnetic-labeled cell tracking, it is essential to expand our knowledge of the time course of SPIONs after cell incorporation and transplantation. This review focuses on the recent advances in tracking SPION-labeled stem cells, analyzing the possibilities and limitations of their use, not only focusing on myocardial infarction but also discussing other models.

In Vivo Tracking of Cell Therapies for Cardiac Diseases with Nuclear Medicine

Even though heart diseases are amongst the main causes of mortality and morbidity in the world, existing treatments are limited in restoring cardiac lesions. Cell transplantations, originally developed for the treatment of hematologic ailments, are presently being explored in preclinical and clinical trials for cardiac diseases. Nonetheless, little is known about the possible efficacy and mechanisms for these therapies and they are the center of continuous investigation. In this scenario, noninvasive imaging techniques lead to greater comprehension of cell therapies. Radiopharmaceutical cell labeling, firstly developed to track leukocytes, has been used successfully to evaluate the migration of cell therapies for myocardial diseases. A substantial rise in the amount of reports employing this methodology has taken place in the previous years. We will review the diverse radiopharmaceuticals, imaging modalities, and results of experimental and clinical studies published until now. Also, we report on current limitations and potential advances of radiopharmaceutical labeling for cell therapies in cardiac diseases.

Pilot safety study of intrabronchial instillation of bone marrow-derived mononuclear cells in patients with silicosis

Background

Silicosis is an occupational disease for which no effective treatment is currently known. Systemic administration of bone marrow-derived mononuclear cells (BMDMCs) has shown to be safe in lung diseases. However, so far, no studies have analyzed whether bronchoscopic instillation of autologous BMDMCs is a safe route of administration in patients with silicosis.

Methods

We conducted a prospective, non-randomized, single-center longitudinal study in five patients. Inclusion criteria were age 18–50 years, chronic and accelerated silicosis, forced expiratory volume in 1 s <60 % and >40 %, forced vital capacity ≥60 % and arterial oxygen saturation >90 %. The exclusion criteria were smoking, active tuberculosis, neoplasms, autoimmune disorders, heart, liver or renal diseases, or inability to undergo bronchoscopy. BMDMCs were administered through bronchoscopy (2 × 10⁷ cells) into both lungs. Physical examination, laboratory evaluations, quality of life questionnaires, computed tomography of the chest, lung function tests, and perfusion scans were performed before the start of treatment and up to 360 days after BMDMC therapy. Additionally, whole-body and planar scans were evaluated 2 and 24 h after instillation.

Results

No adverse events were observed during and after BMDMC administration. Lung function, quality of life and radiologic features remained stable throughout follow-up. Furthermore, an early increase of perfusion in the base of both lungs was observed and sustained after BMDMC administration.

Conclusion

Administration of BMDMCs through bronchoscopy appears to be feasible and safe in accelerated and chronic silicosis. This pilot study provides a basis for prospective randomized trials to assess the efficacy of this treatment approach.

Clinical trials.gov identifier

NCT01239862 Date of Registration: November 10, 2010

99m-Technetium binding site in bone marrow mononuclear cells

INTRODUCTION

The increasing interest in 99m-technetium ((99m)Tc)-labeled stem cells encouraged us to study the (99m)Tc binding sites in stem cell compartments.

METHODS

Bone marrow mononuclear cells were collected from femurs and tibia of rats. Cells were labeled with (99m)Tc by a direct method, in which reduced molecules react with (99m)Tc with the use of chelating agents, and lysed carefully in an ultrasonic apparatus. The organelles were separated by means of differential centrifugation. At the end of this procedure, supernatants and pellets were counted, and the percentages of radioactivity (in megabecquerels) bound to the different cellular fractions were determined. Percentages were calculated by dividing the radioactivity in each fraction by total radioactivity in the sample. The pellets were separated and characterized by their morphology on electron microscopy.

RESULTS

The labeling procedure did not affect viability of bone marrow mononuclear cells. Radioactivity distributions in bone marrow mononuclear cell organelles, obtained in five independent experiments, were approximately 38.5 % in the nuclei-rich fraction, 5.3 % in the mitochondria-rich fraction, 2.2 % in microsomes, and 54 % in the cytosol. Our results showed that most of the radioactivity remained in the cytosol; therefore, this is an intracellular labeling procedure that has ribosomes unbound to membrane and soluble molecules as targets. However, approximately 39 % of the radioactivity remained bound to the nuclei-rich fraction. To confirm that cell disruption and organelle separation were efficient, transmission electron microscopy assays of all pellets were performed.

CONCLUSIONS

Our results showed that most of the radioactivity was present in the cytosol fraction. More studies to elucidate the mechanisms involved in the cellular uptake of (99m)Tc in bone marrow cells are ongoing.

Use of (99m)Tc-doxorubicin scintigraphy in females with breast cancer: a pilot study

OBJECTIVE

Doxorubicin (Eurofarma, São Paulo, Brazil) is an antitumour agent widely used in the treatment of breast cancer and can be used for tumour tracking when labelled with a radionuclide. Here, we present the results obtained with technetium-99m ((99m)Tc)-doxorubicin, using the direct method, to evaluate its uptake in breast cancer.

METHODS

Four females with confirmed breast carcinoma diagnosis and breast image reporting and data system Category 5 on mammography underwent whole-body and thorax single-photon emission CT/CT imaging 1 and 3 h after (99m)Tc-doxorubicin administration.

RESULTS

We observed increased uptake in breast carcinoma lesions and elimination via renal and hepatic pathways.

CONCLUSION

These preliminary results suggest that (99m)Tc-doxorubicin may be a promising radiopharmaceutical for the evaluation of patients with breast cancer. Further studies are ongoing.

ADVANCES IN KNOWLEDGE

To our knowledge, this is the first study to evaluate the use of a directly labelled doxorubicin tracer in humans. (99m)Tc-doxorubicin could provide information on the response of tumours to doxorubicin.

Stem Cell-Based Therapies in Chagasic Cardiomyopathy

Chagas disease is caused by Trypanosoma cruzi and can lead to a dilated cardiomyopathy decades after the prime infection by the parasite. As with other dilated cardiomyopathies, conventional pharmacologic therapies are not always effective and as heart failure progresses patients need heart transplantation. Therefore alternative therapies are highly desirable and cell-based therapies have been investigated in preclinical and clinical studies. In this paper we review the main findings of such studies and discuss future directions for stem cell-based therapies in chronic chagasic cardiomyopathy.

Stem cell imaging: from bench to bedside

Although cellular therapies hold great promise for the treatment of human disease, results from several initial clinical trials have not shown a level of efficacy required for their use as a first line therapy. Here we discuss how in vivo molecular imaging has helped identify barriers to clinical translation and potential strategies that may contribute to successful transplantation and improved outcomes, with a focus on cardiovascular and neurological diseases. We conclude with a perspective on the future role of molecular imaging in defining safety and efficacy for clinical implementation of stem cell therapies.

Molecular imaging, biodistribution and efficacy of mesenchymal bone marrow cell therapy in a mouse model of Chagas disease

Chagasic cardiomyopathy, resulting from infection with the parasite Trypanosoma cruzi, was discovered more than a century ago and remains an incurable disease. Due to the unique properties of mesenchymal stem cells (MSC) we hypothesized that these cells could have therapeutic potential for chagasic cardiomyopathy. Recently, our group pioneered use of nanoparticle-labeled MSC to correlate migration with its effect in an acute Chagas disease model. We expanded our investigation into a chronic model and performed more comprehensive assays. Infected mice were treated with nanoparticle-labeled MSC and their migration was correlated with alterations in heart morphology, metalloproteinase activity, and expression of several proteins. The vast majority of labeled MSC migrated to liver, lungs and spleen whereas a small number of cells migrated to chagasic hearts. Magnetic resonance imaging demonstrated that MSC therapy reduced heart dilatation. Additionally metalloproteinase activity was higher in heart and other organs of infected mice. Protein expression analyses revealed that connexin 43, laminin γ1, IL-10 and INF-γ were affected by the disease and recovered after cell therapy. Interestingly, MSC therapy led to upregulation of SDF-1 and c-kit in the hearts. The beneficial effect of MSC therapy in Chagas disease is likely due to an indirect action of the cells of the heart, rather than the incorporation of large numbers of stem cells into working myocardium.

Biodistribution of bone marrow mononuclear cells after intra-arterial or intravenous transplantation in subacute stroke patients

AIMS

To assess the biodistribution of bone marrow mononuclear cells (BMMNC) delivered by different routes in patients with subacute middle cerebral artery ischemic stroke.

PATIENTS & METHODS

This was a nonrandomized, open-label Phase I clinical trial. After bone marrow harvesting, BMMNCs were labeled with technetium-99m and intra-arterially or intravenously delivered together with the unlabeled cells. Scintigraphies were carried out at 2 and 24 h after cell transplantation. Clinical follow-up was continued for 6 months.

RESULTS

Twelve patients were included, between 19 and 89 days after stroke, and received 1-5 × 10(8) BMMNCs. The intra-arterial group had greater radioactive counts in the liver and spleen and lower counts in the lungs at 2 and 24 h, while in the brain they were low and similar for both routes.

CONCLUSION

BMMNC labeling with technetium-99m allowed imaging for up to 24 h after intra-arterial or intravenous injection in stroke patients.

Bone marrow-derived cell therapy in chagasic cardiac disease: a review of pre-clinical and clinical results

Chagas disease is caused by a protozoan parasite Trypanosoma cruzi, which infects people through blood sucking insects. It is endemic in Latin America and the disease is being spread to developed countries as a result of the migration of infected individuals. In its chronic stage, Chagas disease can lead to a severe cardiomyopathy for which there is currently no cure. End-stage patients require heart transplantation, thus demanding new therapeutic modalities. Cell-based therapy has been proposed as an alternative for various forms of heart disease. Here we review the experimental evidence that led to the use of bone marrow-derived cells in putative therapy for chronic chagasic cardiomyopathy in animal models and in clinical trials, discussing the reasons for failure of the translation of results from mice to men.

Cell therapy in Chagas cardiomyopathy (Chagas arm of the multicenter randomized trial of cell therapy in cardiopathies study): a multicenter randomized trial

BACKGROUND

Previous studies suggested that transplantation of autologous bone marrow-derived mononuclear cells (BMNCs) improves heart function in chronic chagasic cardiomyopathy. We report the results of the first randomized trial of BMNC therapy in chronic chagasic cardiomyopathy.

METHODS AND RESULTS

Patients 18 to 75 years of age with chronic chagasic cardiomyopathy, New York Heart Association class II to IV heart failure, left ventricular ejection fraction (LVEF) <35, and optimized therapy were randomized to intracoronary injection of autologous BMNCs or placebo. The primary end point was the difference in LVEF from baseline to 6 and 12 months after treatment between groups. Analysis was by intention to treat and powered to detect an absolute between-group difference of 5. Between July 2005 and October 2009, 234 patients were enrolled. Two patients abandoned the study and 49 were excluded because of protocol violation. The remaining 183 patients, 93 in the placebo group and 90 in the BMNC group, had a trimmed mean age of 52.4 years (range, 50.8-54.0 years) and LVEF of 26.1 (range, 25.1-27.1) at baseline. Median number of injected BMNCs was 2.20×10(8) (range, 1.40-3.50×10(8)). Change in LVEF did not differ significantly between treatment groups: trimmed mean change in LVEF at 6 months, 3.0 (1.3-4.8) for BMNCs and 2.5 (0.6-4.5) for placebo (P=0.519); change in LVEF at 12 months, 3.5 (1.5-5.5) for BMNCs and 3.7 (1.5-6.0) for placebo (P=0.850). Left ventricular systolic and diastolic volumes, New York Heart Association functional class, Minnesota quality-of-life questionnaire, brain natriuretic peptide concentrations, and 6-minute walking test did also not differ between groups.

CONCLUSION

Intracoronary injection of autologous BMNCs does not improve left ventricular function or quality of life in patients with chronic chagasic cardiomyopathy.

Cell-based therapy in Chagas disease

Chagas disease was first described one century ago, yet the mechanisms underlying chagasic cardiomyopathy remain elusive. Disease progression often leads to heart failure and patients with this infectious cardiomyopathy have a poor prognosis. Treatment options for heart failure due to Chagas disease are not different from standard therapy. Over the past decade, cell-based therapies have emerged as a new alternative in the treatment of this disease, not only because of the possibility of replacing lost vessels and cardiomyocytes but also because these cells could potentially influence the microenvironmental changes that perpetuate the disease. In this chapter, we will review current knowledge on cell-based therapies for the treatment of Chagas disease.