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1.
Sci Rep ; 13(1): 12240, 2023 07 28.
Article in English | MEDLINE | ID: mdl-37507448

ABSTRACT

Rejuvenation of an old organism was achieved in heterochronic parabiosis experiments, implicating different soluble factors in this effect. Extracellular vesicles (EVs) are the secretory effectors of many cells, including cardiosphere-derived cells (CDCs) with demonstrated anti-senescent effect. 1. To determine the role of EVs (versus other blood fractions) on the rejuvenating effect of the young blood. 2. To evaluate the anti-aging properties of therapeutically administered EVs secreted by young-CDCs in an old organism. Neonatal blood fractioned in 4 components (whole blood, serum, EV-depleted serum and purified EVs) was used to treat old human cardiac stromal cells (CSPCs). CDCs were generated from neonatal rat hearts and the secreted CDC-EVs were purified. CDC-EVs were then tested in naturally-aged rats, using monthly injections over 4-months period. For validation in human samples, pediatric CDC-EVs were tested in aged human CSPCs and progeric fibroblasts. While the purified EVs reproduced the rejuvenating effects of the whole blood, CSPCs treated with EV-depleted serum exhibited the highest degree of senescence. Treatment with young CDC-EVs induce structural and functional improvements in the heart, lungs, skeletal muscle, and kidneys of old rats, while favorably modulating glucose metabolism and anti-senescence pathways. Lifespan was prolonged. EVs secreted by young CDCs exert broad-ranging anti-aging effects in aged rodents and in cellular models of human senescence. Our work not only identifies CDC-EVs as possible therapeutic candidates for a wide range of age-related pathologies, but also raises the question of whether EVs function as endogenous modulators of senescence.


Subject(s)
Extracellular Vesicles , Humans , Rats , Animals , Child , Aged , Extracellular Vesicles/metabolism , Aging , Heart , Fibroblasts , Lung , Cellular Senescence/physiology
2.
Eur Heart J ; 43(22): 2139-2156, 2022 06 06.
Article in English | MEDLINE | ID: mdl-35262692

ABSTRACT

AIMS: Cardiomyopathy patients are prone to ventricular arrhythmias (VA) and sudden cardiac death. Current therapies to prevent VA include radiofrequency ablation to destroy slowly conducting pathways of viable myocardium which support re-entry. Here, we tested the reverse concept, namely that boosting local tissue viability in zones of slow conduction might eliminate slow conduction and suppress VA in ischaemic cardiomyopathy. METHODS AND RESULTS: Exosomes are extracellular vesicles laden with bioactive cargo. Exosomes secreted by cardiosphere-derived cells (CDCEXO) reduce scar and improve heart function after intramyocardial delivery. In a VA-prone porcine model of ischaemic cardiomyopathy, we injected CDCEXO or vehicle into zones of delayed conduction defined by electroanatomic mapping. Up to 1-month post-injection, CDCEXO, but not the vehicle, decreased myocardial scar, suppressed slowly conducting electrical pathways, and inhibited VA induction by programmed electrical stimulation. In silico reconstruction of electrical activity based on magnetic resonance images accurately reproduced the suppression of VA inducibility by CDCEXO. Strong anti-fibrotic effects of CDCEXO, evident histologically and by proteomic analysis from pig hearts, were confirmed in a co-culture assay of cardiomyocytes and fibroblasts. CONCLUSION: Biological substrate modification by exosome injection may be worth developing as a non-destructive alternative to conventional ablation for the prevention of recurrent ventricular tachyarrhythmias.


Subject(s)
Cardiomyopathies , Catheter Ablation , Myocardial Ischemia , Tachycardia, Ventricular , Animals , Arrhythmias, Cardiac/etiology , Arrhythmias, Cardiac/prevention & control , Cardiomyopathies/surgery , Catheter Ablation/methods , Cicatrix/prevention & control , Humans , Myocardial Ischemia/surgery , Myocardial Ischemia/therapy , Proteomics , Swine , Tachycardia, Ventricular/etiology , Tachycardia, Ventricular/prevention & control
3.
J Heart Lung Transplant ; 40(11): 1387-1395, 2021 11.
Article in English | MEDLINE | ID: mdl-34281778

ABSTRACT

BACKGROUND: Extracellular vesicles (EVs) from heart stromal/progenitor cells modulate innate immunity, with salutary effects in a variety of cardiac disease models. Little is known, however, about the effects of these EVs on adaptive immunity. METHODS: Ex vivo differentiation of naïve CD4+ T cells was conducted to assess the effect of EVs on cytokine production and proliferation of Th1, Th2, Th17, and regulatory T (Treg) cells. These effects were further tested in vivo using the experimental autoimmune myocarditis (EAM) model. RESULTS: Using differentiated CD4+ T cells, we show that EVs secreted by human-derived heart stromal/progenitor cells selectively influence the phenotype, activity, and proliferation of regulatory T (Treg) cells. Exposure of Treg cells to EVs results in faster proliferation, augmented production of IL-10, and polarization toward an intermediate FOXP3+RORγt+ phenotype. In experimental autoimmune myocarditis, EVs attenuate cardiac inflammation and functional decline, in association with increased numbers of splenic IL10+-Treg cells. CONCLUSIONS: T cell modulation by EVs represents a novel therapeutic approach to inflammation, harnessing endogenous immunosuppressive mechanisms that may be applied in solid organ transplantation, graft-versus-host disease, and autoimmune disorders.


Subject(s)
Adaptive Immunity/immunology , Autoimmune Diseases/immunology , Extracellular Vesicles/metabolism , Immunity, Innate , Lymphocyte Activation/immunology , Myocarditis/immunology , T-Lymphocytes, Regulatory/immunology , Animals , Autoimmune Diseases/pathology , Cell Differentiation , Cell Proliferation , Cells, Cultured , Cytokines/metabolism , Disease Models, Animal , Female , Mice , Myocarditis/pathology , Rats , Rats, Inbred Lew , T-Lymphocytes, Regulatory/pathology
4.
J Extracell Vesicles ; 10(3): e12045, 2021 01.
Article in English | MEDLINE | ID: mdl-33456725

ABSTRACT

Extracellular vesicles (EVs) from cardiac stromal cells, developed as therapeutic candidates, improve dystrophic muscle function when administered parenterally, but oral delivery remains untested. We find that casein, the dominant protein in breast milk, enhances the uptake and bioactivity of ingested heart-derived EVs, altering gene expression in blood cells and enhancing muscle function in mdx mice with muscular dystrophy. Thus, EVs, administered orally, are absorbed and exert disease-modifying bioactivity in vivo. Formulating EVs with casein enhances uptake and markedly expands the range of potential therapeutic applications.


Subject(s)
Caseins/metabolism , Extracellular Vesicles/metabolism , Muscular Dystrophies/therapy , Animals , Eating , Female , Mice , Mice, Inbred mdx , Milk, Human/metabolism , Muscular Diseases/therapy , Myoblasts, Cardiac/metabolism , Stromal Cells/metabolism
5.
Heart Rhythm ; 17(6): 1025-1033, 2020 06.
Article in English | MEDLINE | ID: mdl-32068183

ABSTRACT

BACKGROUND: Although ∼20% of the elderly population develops atrial fibrillation (AF), little is known about the mechanisms. Heart failure with preserved ejection fraction (HFpEF), which is associated with AF, is more common in aged women than in men. OBJECTIVE: The purpose of this study was to identify potential mechanisms of AF in an age-related HFpEF model. METHODS: In aged female Fischer F344 rats (21- to 24-month-old), which are prone to HFpEF, we induced AF by atrial pacing. Young Fischer F344 female rats (3- to 4-month-old) and age-matched Sprague Dawley female rats (27-month-old) served as controls. Phenotyping included echocardiography to assess left ventricular structure/function; in vivo electrophysiology and ex vivo high-resolution optical mapping to assess AF vulnerability; systemic and atrial inflammatory profiling; atrial histology; and expression of inflammasome signaling proteins. RESULTS: Aged rats developed left ventricular hypertrophy, left atrial enlargement, diastolic dysfunction, and pulmonary congestion, without ejection fraction impairment, thus meeting the criteria for HFpEF. Increased serum inflammatory markers, hypertension, and obesity further characterize aged females. Sinoatrial and atrioventricular node dysfunction was associated with the high inducibility of AF in aged rats. Ex vivo electrical activation mapping revealed abnormal ß-adrenergic responsiveness and slowed conduction velocity. Atrial inflammasome signaling was enhanced in aged rats, which may contribute to fibrotic remodeling and high AF susceptibility. CONCLUSION: Together, our data demonstrate that aging-related atrial remodeling and HFpEF are associated with atrial enlargement, fibrosis, conduction abnormalities, and nodal dysfunction, favoring a substrate conducive to AF.


Subject(s)
Atrial Remodeling , Heart Atria/physiopathology , Heart Failure/physiopathology , Heart Ventricles/diagnostic imaging , Ventricular Function, Left/physiology , Animals , Disease Models, Animal , Echocardiography , Female , Heart Atria/diagnostic imaging , Heart Failure/diagnosis , Heart Ventricles/physiopathology , Rats , Rats, Inbred F344 , Rats, Sprague-Dawley , Stroke Volume/physiology
6.
J Am Coll Cardiol ; 73(13): 1673-1687, 2019 04 09.
Article in English | MEDLINE | ID: mdl-30947921

ABSTRACT

BACKGROUND: Right ventricular (RV) pacing-induced cardiomyopathy (PICM) occurs in ∼30% of patients with RV leads. This study evaluated the long-term effects of restoring antegrade conduction with a biological pacemaker in a porcine model of RV PICM. OBJECTIVES: The goal of this study was to determine if antegrade biological pacing can attenuate RV PICM. METHODS: In pigs with complete atrioventricular (AV) block, transcription factor T-box 18 (TBX18) was injected into the His bundle region in either of 2 experimental protocols: protocol A sought to prevent PICM, and protocol B sought to reverse PICM. In protocol A, we injected adenoviral vectors expressing TBX18 (or the reporter construct green fluorescent protein) after AV node ablation, and observed the animals for 8 weeks. In protocol B, PICM was established by using AV node ablation and 4 weeks of electronic RV pacing, at which point TBX18 was injected into the His bundle region. RESULTS: In protocol A, TBX18 biological pacing led to superior chronotropic support (62.4 ± 3 beats/min vs. 50.4 ± 0.4 beats/min; p = 0.01), lower backup pacemaker utilization (45 ± 2.6% vs. 94.6 ± 1.4%; p = 0.001), and greater ejection fraction (58.5 ± 1.3% vs. 46.7 ± 2%; p = 0.001). In protocol B, full-blown RV PICM was evident 4 weeks after complete AV block in both groups; subsequent intervention led to higher mean heart rate (56 ± 2 beats/min vs. 50.1 ± 0.4 beats/min; p = 0.05), less backup pacemaker utilization (53 ± 8.2% vs. 95 ± 1.6%; p = 0.003), and a greater ejection fraction (61.7 ± 1.3% vs. 49 ± 1.6%; p = 0.0003) in TBX18-injected animals versus control animals. CONCLUSIONS: In a preclinical model, pacemaker-induced cardiomyopathy can be prevented, and reversed, by restoring antegrade conduction with TBX18 biological pacing.


Subject(s)
Atrioventricular Block/therapy , Cardiac Pacing, Artificial/adverse effects , Cardiomyopathies/prevention & control , Genetic Therapy , T-Box Domain Proteins/therapeutic use , Animals , Biological Clocks , Cardiomyopathies/etiology , Swine
7.
Hypertension ; 72(2): 370-380, 2018 08.
Article in English | MEDLINE | ID: mdl-29866742

ABSTRACT

Hypertension often leads to cardiovascular disease and kidney dysfunction. Exosomes secreted from cardiosphere-derived cells (CDC-exo) and their most abundant small RNA constituent, the Y RNA fragment EV-YF1, exert therapeutic benefits after myocardial infarction. Here, we investigated the effects of CDC-exo and EV-YF1, each administered individually, in a model of cardiac hypertrophy and kidney injury induced by chronic infusion of Ang (angiotensin) II. After 2 weeks of Ang II, multiple doses of CDC-exo or EV-YF1 were administered retro-orbitally. Ang II infusion induced an elevation in systolic blood pressure that was not affected by CDC-exo or EV-YF1. Echocardiography confirmed that Ang II infusion led to cardiac hypertrophy. CDC-exo and EV-YF1 both attenuated cardiac hypertrophy and reduced cardiac inflammation and fibrosis. In addition, both CDC-exo and EV-YF1 improved kidney function and diminished renal inflammation and fibrosis. The beneficial effects of CDC-exo and EV-YF1 were associated with changes in the expression of the anti-inflammatory cytokine IL (interleukin)-10 in plasma, heart, spleen, and kidney. In summary, infusions of CDC-exo or EV-YF1 attenuated cardiac hypertrophy and renal injury induced by Ang II infusion, without affecting blood pressure, in association with altered IL-10 expression. Exosomes and their defined noncoding RNA contents may represent potential new therapeutic approaches for hypertension-associated cardiovascular and renal damage.


Subject(s)
Acute Kidney Injury/etiology , Angiotensin II/pharmacology , Exosomes/genetics , Hypertension/genetics , Interleukin-10/metabolism , Myocytes, Cardiac/metabolism , RNA/genetics , Acute Kidney Injury/genetics , Acute Kidney Injury/metabolism , Animals , Cells, Cultured , Disease Models, Animal , Exosomes/metabolism , Humans , Hypertension/complications , Hypertension/metabolism , Male , Mice , Mice, Inbred C57BL , Myocytes, Cardiac/pathology
8.
Eur Heart J ; 38(39): 2957-2967, 2017 Oct 14.
Article in English | MEDLINE | ID: mdl-29020403

ABSTRACT

AIM: The aim is to assess the effects of CDCs on heart structure, function, gene expression, and systemic parameters in aged rats. Diastolic dysfunction is characteristic of aged hearts. Cardiosphere-derived cell (CDC) therapy has exhibited several favourable effects on heart structure and function in humans and in preclinical models; however, the effects of CDCs on aging have not been evaluated. METHODS AND RESULTS: We compared intra-cardiac injections of neonatal rat CDCs to vehicle (phosphate-buffered saline, PBS) in 21.8 ± 1.6 month-old rats (mean ± standard deviation; n = 23 total). Ten rats 4.1 ± 1.5 months of age comprised a young reference group. Blood, echocardiographic, haemodynamic and treadmill stress tests were performed at baseline in all animals, and 1 month after treatment in old animals. Histology and the transcriptome were assessed after terminal phenotyping. For in vitro studies, human heart progenitors from older donors, or cardiomyocytes from aged rats were exposed to human CDCs or exosomes secreted by CDCs (CDC-XO) from paediatric donors. Transcriptomic analysis revealed that CDCs, but not PBS, recapitulated a youthful pattern of gene expression in the hearts of old animals (85.5% of genes differentially expressed, P < 0.05). Telomeres in heart cells were longer in CDC-transplanted animals (P < 0.0001 vs. PBS). Cardiosphere-derived cells attenuated hypertrophy by echo (P < 0.01); histology confirmed decreases in cardiomyocyte area (P < 0.0001) and myocardial fibrosis (P < 0.05) vs. PBS. Cardiosphere-derived cell injection improved diastolic dysfunction [lower E/A (P < 0.01), E/E' (P = 0.05), end-diastolic pressure-volume relationship (P < 0.05) compared with baseline), and lowered serum brain natriuretic peptide (both P < 0.05 vs. PBS). In CDC-transplanted old rats, exercise capacity increased ∼20% (P < 0.05 vs. baseline), body weight decreased ∼30% less (P = 0.05 vs. PBS) and hair regrowth after shaving was more robust (P < 0.05 vs. PBS). Serum biomarkers of inflammation (IL-10, IL-1b, and IL-6) improved in the CDC group (P < 0.05 for each, all vs. PBS). Young CDCs secrete exosomes which increase telomerase activity, elongate telomere length, and reduce the number of senescent human heart cells in culture. CONCLUSION: Young CDCs rejuvenate old animals as gauged by cardiac gene expression, heart function, exercise capacity, and systemic biomarkers.


Subject(s)
Cell- and Tissue-Based Therapy/methods , Heart/physiology , Stem Cell Transplantation/methods , Aged , Analysis of Variance , Animals , Cellular Senescence/physiology , Fetal Stem Cells/cytology , Humans , Middle Aged , Myocytes, Cardiac/cytology , Physical Conditioning, Animal/physiology , Rats, Inbred F344 , Rats, Sprague-Dawley , Regeneration/physiology , Rejuvenation/physiology , Spheroids, Cellular/cytology , Telomere/physiology
9.
Eur Heart J ; 38(3): 201-211, 2017 01 14.
Article in English | MEDLINE | ID: mdl-28158410

ABSTRACT

Aims: Naturally secreted nanovesicles known as exosomes are required for the regenerative effects of cardiosphere-derived cells (CDCs), and exosomes mimic the benefits of CDCs in rodents. Nevertheless, exosomes have not been studied in a translationally realistic large-animal model. We sought to optimize delivery and assess the efficacy of CDC-secreted exosomes in pig models of acute (AMI) and convalescent myocardial infarction (CMI). Methods and Results: In AMI, pigs received human CDC exosomes (or vehicle) by intracoronary (IC) or open-chest intramyocardial (IM) delivery 30 min after reperfusion. No-reflow area and infarct size (IS) were assessed histologically at 48 h. Intracoronary exosomes were ineffective, but IM exosomes decreased IS from 80 ± 5% to 61 ± 12% (P= 0.001) and preserved left ventricular ejection fraction (LVEF). In a randomized placebo-controlled study of CMI, pigs 4 weeks post-myocardial infarction (MI) underwent percutaneous IM delivery of vehicle (n = 6) or CDC exosomes (n = 6). Magnetic resonance imaging (MRI) performed before and 1 month after treatment revealed that exosomes (but not vehicle) preserved LV volumes and LVEF (−0.1 ± 2.2% vs. −5.4 ± 3.6%, P= 0.01) while decreasing scar size. Histologically, exosomes decreased LV collagen content and cardiomyocyte hypertrophy while increasing vessel density. Conclusion: Cardiosphere-derived cell exosomes delivered IM decrease scarring, halt adverse remodelling and improve LVEF in porcine AMI and CMI. While conceptually attractive as cell-free therapeutic agents for myocardial infarction, exosomes have the disadvantage that IM delivery is necessary.


Subject(s)
Cicatrix/prevention & control , Exosomes/transplantation , Myocardial Infarction/therapy , Acute Disease , Animals , Chronic Disease , Disease Models, Animal , Female , Magnetic Resonance Angiography , Myocardial Infarction/physiopathology , Myocardium/metabolism , Myocytes, Cardiac/metabolism , Neovascularization, Physiologic/physiology , Random Allocation , Regeneration/physiology , Spheroids, Cellular/metabolism , Swine , Swine, Miniature , Ventricular Function/physiology , Ventricular Remodeling/physiology
10.
EMBO Mol Med ; 9(3): 337-352, 2017 03.
Article in English | MEDLINE | ID: mdl-28167565

ABSTRACT

Cardiosphere-derived cells (CDCs) reduce myocardial infarct size via secreted extracellular vesicles (CDC-EVs), including exosomes, which alter macrophage polarization. We questioned whether short non-coding RNA species of unknown function within CDC-EVs contribute to cardioprotection. The most abundant RNA species in CDC-EVs is a Y RNA fragment (EV-YF1); its relative abundance in CDC-EVs correlates with CDC potency in vivo Fluorescently labeled EV-YF1 is actively transferred from CDCs to target macrophages via CDC-EVs. Direct transfection of macrophages with EV-YF1 induced transcription and secretion of IL-10. When cocultured with rat cardiomyocytes, EV-YF1-primed macrophages were potently cytoprotective toward oxidatively stressed cardiomyocytes through induction of IL-10. In vivo, intracoronary injection of EV-YF1 following ischemia/reperfusion reduced infarct size. A fragment of Y RNA, highly enriched in CDC-EVs, alters Il10 gene expression and enhances IL-10 protein secretion. The demonstration that EV-YF1 confers cardioprotection highlights the potential importance of diverse exosomal contents of unknown function, above and beyond the usual suspects (e.g., microRNAs and proteins).


Subject(s)
Extracellular Vesicles/metabolism , Interleukin-10/metabolism , Macrophages/immunology , Myocardial Infarction/prevention & control , Myocytes, Cardiac/metabolism , RNA, Small Cytoplasmic/metabolism , Animals , Cells, Cultured , Coculture Techniques , Disease Models, Animal , Humans , RNA, Small Cytoplasmic/administration & dosage , Rats, Wistar , Treatment Outcome
11.
Tob Control ; 25(Suppl 2): ii94-ii102, 2016 11.
Article in English | MEDLINE | ID: mdl-27633763

ABSTRACT

OBJECTIVE: The aim of this study was to evaluate the distribution, concentration and toxicity of cinnamaldehyde in electronic cigarette (e-cigarette) refill fluids and aerosols. METHODS: The distribution and concentration of cinnamaldehyde were determined in 39 e-cigarette refill fluids plus 6 duplicates using gas chromatography and mass spectrometry (GC/MS). A cinnamaldehyde toxicity profile was established for embryonic and adult cells using a live cell imaging assay, immunocytochemistry, the comet assay and a recovery assay. RESULTS: Twenty of the 39 refill fluids contained cinnamaldehyde at concentrations that are cytotoxic to human embryonic and lung cells in the MTT assay. Cinnamon Ceylon aerosol produced in a cartomizer-style e-cigarette was cytotoxic. Cinnamon Ceylon aerosols and refill fluid aerosols (80% propylene glycol or cinnamaldehyde/propylene glycol) made using a tank/boxmod e-cigarette were more cytotoxic at 5 V than 3 V. Using GC/MS, aerosols produced at 5 V contained 10 additional peaks not present in aerosol generated at 3 V. One of these, 2,3-butandione (diacetyl), was confirmed with an authentic standard. Cinnamaldehyde depolymerised microtubules in human pulmonary fibroblasts. At concentrations that produced no effect in the MTT assay, cinnamaldehyde decreased growth, attachment and spreading; altered cell morphology and motility; increased DNA strand breaks; and increased cell death. At the MTT IC50 concentration, lung cells were unable to recover from cinnamaldehyde after 2 hours of treatment, whereas embryonic cells recovered after 8 hours. CONCLUSIONS: Cinnamaldehyde-containing refill fluids and aerosols are cytotoxic, genotoxic and low concentrations adversely affect cell processes and survival. These data indicate that cinnamaldehyde in e-cigarette refill fluids/aerosols may impair homeostasis in the respiratory system.


Subject(s)
Acrolein/analogs & derivatives , Electronic Nicotine Delivery Systems , Fibroblasts/drug effects , Lung/drug effects , Acrolein/administration & dosage , Acrolein/chemistry , Acrolein/toxicity , Adult , Aerosols , Cells, Cultured , Comet Assay , DNA Breaks/drug effects , Embryonic Stem Cells/cytology , Embryonic Stem Cells/drug effects , Fibroblasts/cytology , Gas Chromatography-Mass Spectrometry , Humans , Immunohistochemistry , Inhibitory Concentration 50 , Lung/cytology , Time Factors
12.
J Heart Lung Transplant ; 35(11): 1348-1357, 2016 11.
Article in English | MEDLINE | ID: mdl-27342903

ABSTRACT

BACKGROUND: A single dose of allogeneic cardiosphere-derived cells (CDCs) improves cardiac function and reduces scarring, and increases viable myocardium in the infarcted rat and pig heart without eliciting a detrimental immune response. Clinical trials using single doses of allogeneic human CDCs are underway. It is unknown whether repeat dosing confers additional benefit or if it elicits an immune response. METHODS: Wistar-Kyoto rats underwent coronary artery ligation and intramyocardial injection of CDCs, with a second thoracotomy and repeat CDC injection 3 weeks later. Treatment permutations included 2 doses of allogeneic Brown-Norway CDCs (n = 24), syngeneic Wistar-Kyoto CDCs (n = 24), xenogeneic human CDCs (n = 24) or saline (n = 8). Cardiac function was assessed by transthoracic echocardiography, infarct size and inflammatory infiltration by histology, and cellular and humoral immune responses by lymphocyte proliferation and alloantibody assays. RESULTS: Repeat dosing of allogeneic and syngeneic CDCs improved ejection fraction by 5.2% (95% CI 2.1 to 8.3) and 6.8% (95% CI 3.8 to 9.8) after the first dose, and by 3.4% (95% CI 0.1% to 6.8%) and 6.4% (95% CI 4.2% to 8.6%) after the second dose. Infarct size was equally reduced with repeat dosing of syngeneic and allogeneic CDCs relative to xenogeneic and control treatments (p < 0.0001). Significant rejection-like infiltrates were present only in the xenogeneic group; likewise, lymphocyte proliferation and antibody assays were positive in the xenogeneic and negative in syngeneic and allogeneic groups. CONCLUSIONS: Repeat dosing of allogeneic CDCs in immunocompetent rats is safe and effective, consistent with the known immunomodulatory and anti-inflammatory properties of CDCs. These findings motivate clinical testing of repeatedly dosed CDCs for chronic heart disease.


Subject(s)
Cell- and Tissue-Based Therapy/methods , Graft Rejection/prevention & control , Immunization/methods , Myocardial Infarction/therapy , Myocytes, Cardiac/transplantation , Stem Cell Transplantation/methods , Ventricular Remodeling , Animals , Cells, Cultured , Disease Models, Animal , Graft Rejection/diagnosis , Graft Rejection/immunology , Myocardial Infarction/pathology , Myocardial Infarction/physiopathology , Myocytes, Cardiac/cytology , Rats , Rats, Inbred BN , Rats, Inbred WKY , Regenerative Medicine/methods , Transplantation, Homologous , Treatment Outcome , Ventricular Function, Left/physiology
13.
JACC Basic Transl Sci ; 1(1-2): 14-28, 2016.
Article in English | MEDLINE | ID: mdl-27104217

ABSTRACT

BACKGROUND: The pathogenesis of HFpEF is unclear, but fibrosis, inflammation and hypertrophy have been put forth as likely contributors. CDCs are heart-derived cell products with anti-fibrotic and anti-inflammatory properties. OBJECTIVES: We questioned whether allogeneic rat CDCs might be able to decrease manifestations of HFpEF in hypertensive rats. METHODS: Starting at 7 weeks of age, Dahl salt-sensitive rats were fed a high-salt diet for 6-7 weeks and randomized to receive intracoronary CDCs or placebo. Dahl rats fed normal chow served as controls. RESULTS: High-salt rats developed hypertension, left ventricular (LV) hypertrophy and diastolic dysfunction, without impairment of ejection fraction. Four weeks after treatment, diastolic dysfunction resolved in CDC-treated rats but not in placebo. The improved LV relaxation was associated with lower LV end-diastolic pressure, decreased lung congestion and enhanced survival in CDC-treated rats. Histology and echocardiography revealed no decrease in cardiac hypertrophy after CDC treatment, consistent with the finding of sustained, equally-elevated blood pressure in CDC- and placebo-treated rats. Nevertheless, CDC treatment decreased LV fibrosis and inflammatory infiltrates. Serum inflammatory cytokines were likewise decreased after CDC treatment. Whole-transcriptome analysis revealed major HFpEF-related, CDC-reversed changes in numerous transcripts, including many involved in inflammation and/or fibrosis. CONCLUSION: CDCs normalized LV relaxation and LV diastolic pressure while improving survival in a rat model of HFpEF. The benefits of CDCs occurred despite persistent hypertension and cardiac hypertrophy. By selectively reversing inflammation and fibrosis, CDCs may be beneficial in the treatment of HFpEF.

14.
PLoS One ; 11(1): e0144523, 2016.
Article in English | MEDLINE | ID: mdl-26784932

ABSTRACT

Single-vessel, intracoronary infusion of stem cells under stop-flow conditions has proven safe but achieves only limited myocardial coverage. Continuous flow intracoronary delivery to one or more coronary vessels may achieve broader coverage for treating cardiomyopathy, but has not been investigated. Using nonocclusive coronary guiding catheters, we infused allogeneic cardiosphere-derived cells (CDCs) either in a single vessel or sequentially in all three coronary arteries in porcine ischemic cardiomyopathy and used magnetic resonance imaging (MRI) to assess structural and physiological outcomes. Vehicle-infused animals served as controls. Single-vessel stop-flow and continuous-flow intracoronary infusion revealed equivalent effects on scar size and function. Sequential infusion into each of the three major coronary vessels under stop-flow or continuous-flow conditions revealed equal efficacy, but less elevation of necrotic biomarkers with continuous-flow delivery. In addition, multi-vessel delivery resulted in enhanced global and regional tissue function compared to a triple-vessel placebo-treated group. The functional benefits after global cell infusion were accompanied histologically by minimal inflammatory cellular infiltration, attenuated regional fibrosis and enhanced vessel density in the heart. Sequential multi-vessel non-occlusive delivery of CDCs is safe and provides enhanced preservation of left ventricular function and structure. The current findings provide preclinical validation of the delivery method currently undergoing clinical testing in the Dilated cardiomYopathy iNtervention With Allogeneic MyocardIally-regenerative Cells (DYNAMIC) trial of CDCs in heart failure patients.


Subject(s)
Myoblasts, Cardiac/cytology , Myocardial Ischemia/pathology , Myocardial Ischemia/therapy , Stem Cell Transplantation , Stem Cells/cytology , Animals , Cardiomyopathy, Hypertrophic/diagnosis , Cardiomyopathy, Hypertrophic/etiology , Cardiomyopathy, Hypertrophic/pathology , Cardiomyopathy, Hypertrophic/physiopathology , Cell- and Tissue-Based Therapy , Disease Models, Animal , Immunohistochemistry , Magnetic Resonance Imaging , Myocardial Infarction/diagnosis , Myocardial Infarction/mortality , Myocardial Infarction/pathology , Myocardial Infarction/physiopathology , Myocardial Infarction/therapy , Myocardial Ischemia/diagnosis , Myocardial Ischemia/mortality , Myocardial Ischemia/physiopathology , Phenotype , Stroke Volume , Swine , Ventricular Remodeling
15.
J Am Coll Cardiol ; 66(6): 599-611, 2015 Aug 11.
Article in English | MEDLINE | ID: mdl-26248985

ABSTRACT

BACKGROUND: Cardiosphere-derived cells mediate therapeutic regeneration in patients after myocardial infarction and are undergoing further clinical testing for cardiomyopathy. The beneficial effects of cardiosphere-derived cells are mediated by the secretion of exosomes and possibly other extracellular membrane vesicles (EMVs). OBJECTIVES: This study sought to investigate the effect of cardiosphere-derived EMVs (CSp-EMVs) on fibroblasts in vitro and tested whether priming with CSp-EMVs could confer salutary properties on fibroblasts in vivo. METHODS: CSp-EMVs were isolated from serum-free media conditioned for 3 days by cardiospheres. Dermal fibroblasts were primed with CSp-EMVs for 24 h followed by exosomal micro-ribonucleic acid profiling. In vivo, we injected CSp-EMV-primed or -unprimed dermal fibroblasts (or CSp-EMVs) in a chronic rat model of myocardial infarction and defined the functional and structural consequences. RESULTS: CSp-EMVs amplified their own biological signals: exposure of "inert" fibroblasts to CSp-EMVs rendered the fibroblasts therapeutic. Intramyocardially injected CSp-EMV-primed (but not unprimed) fibroblasts increased global pump function and vessel density while reducing scar mass. CSp-EMV priming caused fibroblasts to secrete much higher levels of stromal-cell-derived factor 1 and vascular endothelial growth factor and dramatically changed the micro-ribonucleic acid profile of fibroblast-secreted EMVs in vitro. The priming was followed by significant angiogenic and cardioprotective effects. CONCLUSIONS: CSp-EMVs alter fibroblast phenotype and secretome in a salutary positive-feedback loop. The phenotypic conversion of inert cells to therapeutically active cells reveals a novel mechanism for amplification of exosome bioactivity.


Subject(s)
Albumins/physiology , Apoptosis/physiology , Cell Membrane/physiology , Fibroblasts/physiology , Myocardial Infarction/pathology , Neovascularization, Physiologic/physiology , Albumins/therapeutic use , Animals , Cell Membrane/transplantation , Cells, Cultured , Clathrin-Coated Vesicles/physiology , Clathrin-Coated Vesicles/transplantation , Female , Fibroblasts/transplantation , Fibrosis/pathology , Fibrosis/therapy , Humans , Male , Myocardial Infarction/therapy , Polyesters/therapeutic use , Rats , Rats, Inbred BN , Rats, Inbred WKY , Rats, Sprague-Dawley
16.
Circ Cardiovasc Interv ; 8(5)2015 May.
Article in English | MEDLINE | ID: mdl-25953823

ABSTRACT

BACKGROUND: Preclinical studies in rodents and pigs indicate that the self-assembling microtissues known as cardiospheres may be more effective than dispersed cardiosphere-derived cells. However, the more desirable intracoronary route has been assumed to be unsafe for cardiosphere delivery: Cardiospheres are large (30-150 µm), raising concerns about likely microembolization. We questioned these negative assumptions by evaluating the safety and efficacy of optimized intracoronary delivery of cardiospheres in a porcine model of convalescent myocardial infarction. METHODS AND RESULTS: First, we standardized the size of cardiospheres by modifying culture conditions. Then, dosage was determined by infusing escalating doses of cardiospheres in the left anterior descending artery of naive pigs, looking for acute adverse effects. Finally, in a randomized efficacy study, 14 minipigs received allogeneic cardiospheres (1.3 × 10(6)) or vehicle 1 month after myocardial infarction. Animals underwent magnetic resonance imaging before infusion and 1 month later to assess left ventricular ejection fraction, scar mass, and viable mass. In the dosing study, we did not observe any evidence of microembolization after cardiosphere infusion. In the post-myocardial infarction study, cardiospheres preserved LV function, reduced scar mass and increased viable mass, whereas placebo did not. Moreover, cardiosphere decreased collagen content, and increased vessel densities and myocardial perfusion. Importantly, intracoronary cardiospheres decreased left ventricular end-diastolic pressure and increased cardiac output. CONCLUSIONS: Intracoronary delivery of cardiospheres is safe. Intracoronary cardiospheres are also remarkably effective in decreasing scar, halting adverse remodeling, increasing myocardial perfusion, and improving hemodynamic status after myocardial infarction in pigs. Thus, cardiospheres may be viable therapeutic candidates for intracoronary infusion in selected myocardial disorders.


Subject(s)
Disease Models, Animal , Myocardial Infarction/therapy , Myocytes, Cardiac/transplantation , Stem Cell Transplantation , Vascular Remodeling/physiology , Animals , Coronary Vessels , Infusions, Intra-Arterial , Magnetic Resonance Imaging , Male , Myocardial Infarction/physiopathology , Myocytes, Cardiac/cytology , Swine , Swine, Miniature , Transplantation, Autologous
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