Abstract 21: Ploidy Alteration of Murine Cardiac Progenitor Cells in Response to Infarction Injury

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Kathleen M Broughton ◽  
Bingyan J Wang ◽  
Taeyong Kim ◽  
Sadia Mohsin ◽  
Dieter Kubli ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Biological Properties ◽  
Border Zone ◽  
Myocardial Regeneration ◽  
Mouse Strains ◽  
Cardiac Progenitor Cells ◽  
Regenerative Capacity ◽  
Clonal Lines ◽  
And Gender ◽  
Species Specific

Introduction: Discovery of endogenous cardiac progenitor cells (CPC) prompted intense research efforts in multiple experimental animal models and clinical trials for heart failure treatment. Our lab identified a fundamental difference in ploidy content between rodent (rat, mouse) CPCs possessing mononuclear tetraploid (4n) chromosome content versus large mammal (human, swine) CPCs with mononuclear diploid (2n) content. Ploidy differences raise provocative questions regarding translational applicability of myocardial regeneration in rodents as polyplodization often correlates with enhanced regenerative potential. Hypothesis: Mononuclear chromatin duplication in CPCs improves regenerative capacity of the heart through higher stress resistance and overriding senescence cell-cycle arrest. Methods and Results: Ploidy of cultured CPCs is consistent and stable ploidy content over increased passages with samples from eight humans, two swine strains, six mouse strains, and seven rat clonal lines as determined by karyotype, confocal microscope and flow cytometry analyses. In situ ploidy analysis of CPCs reveals diploid content in human tissue and a mixture of mononuclear diploid and tetraploid nuclei in mouse, confirmed using freshly isolated Lin- c-kit+ CPCs. Tetraploid nuclear phenotype of murine CPCs is markedly different from predominantly diploid (2n) murine c-kit+ cells located in other tissues such as intestine and bone marrow. Higher ploidy content concurrent with expansion of the CPC pool are evident in the border zone at seven days post-infarction in adult FVB mice compared to age and gender matched non-injured hearts. Conclusion: Tetraploid c-kit+ cells found within the rodent heart may contribute to species-specific characteristics of stem cells and myocardial regenerative capacity. Future studies will focus upon the biological properties of diploid versus tetraploid CPCs and advantages of polyploid content for mediating myocardial regeneration.

Abstract 1018: Cardiac Progenitor Cells and Biotinylated IGF-1 Nanofibers Improve Endogenous and Exogenous Myocardial Regeneration after Infarction

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Yu Misao ◽  
Michael E Davis ◽  
Vincent E Segers ◽  
Marcello Rota ◽  
Grazia Esposito ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Combined Treatment ◽  
Volume Ratio ◽  
Experimental Period ◽  
Border Zone ◽  
Myocardial Regeneration ◽  
Prolonged Release ◽  
Cardiac Progenitor Cells ◽  
Receptor System ◽  
Chamber Volume

Cardiac progenitor cells (CPCs) possess the IGF-1-IGF-1 receptor system which promotes cell survival, growth and differentiation. Therefore, we tested whether the local injection of CPCs together with the prolonged release of IGF-1 by self-assembling peptides enhanced myocardial regeneration after infarction. The possibility was raised that this strategy may improve cardiac repair by potentiating the regenerative response of the delivered and resident CPCs. Myocardial infarction was induced in rats and after the injection of 100,000 clonogenic immunocompatible EGFP-positive-CPCs in the border zone, biotinylated IGF-1 nanofibers were delivered to the same region. Four groups of animals were used for comparison: infarcted hearts injected with peptide only, infarcted hearts injected with CPCs only, untreated infarcted hearts and sham operated hearts. All animals received BrdU throughout the 1 month experimental period for the recognition of newly formed cells. Infarct size, ~60%, was comparable in the 4 groups. Although all treated-infarcted hearts showed a reduction in chamber volume and an increase in wall-thickness-to-chamber volume ratio and LV mass-to-chamber volume ratio, the combined treatment had the most positive effect. Similarly, LVEDP, LVDP, and dP/dt improved predominantly in infarcted hearts exposed to CPCs and IGF-1 which possessed a larger number of regenerated myocytes. The newly formed BrdU-positive myocytes consisted of EGFP-positive and EGFP-negative cells. The former category corresponded to the progeny of the injected CPCs and the latter was the product of differentiation of resident CPCs. The regenerated myocytes showed a high degree of differentiation; 20% of myocytes had a volume 2,000 –10,000 μm 3 . This level of maturation was not observed in infarcted hearts treated only with CPCs or IGF1 releasing peptides. Also, administration of CPCs and IGF-1 led to the formation of numerous resistance arterioles and capillary structures within the regenerated myocardium. Thus, the combination of CPCs and IGF-1 biotinylated nanofibers results in an unprecedented degree of myocardial recovery of structure and function after infarction. Importantly, the regenerated myocytes acquire the differentiated adult phenotype.

Abstract 710: Notch1 Receptor Enhances Myocyte Differentiation of Cardiac Progenitor Cells and Myocardial Regeneration After Infarction

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Alessandro Boni ◽  
Angelo Nascimbene ◽  
Robert Siggins ◽  
Konrad Urbanek ◽  
Katsuya Amano ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Molecular Mechanisms ◽  
Notch Pathway ◽  
Border Zone ◽  
Myocardial Regeneration ◽  
Mouse Heart ◽  
Cardiac Progenitor Cells ◽  
Notch 1 ◽  
Secretase Inhibitor

Cardiac progenitor cells (CPCs) have been identified in the adult heart. However, the molecular mechanisms involved in the commitment of CPCs to the myocyte lineage remain to be determined. Notch-1 is a transmembrane receptor activated by the DSL family of ligands which include Jagged1 and Delta-4. Upon ligand binding, the activated receptor undergoes cleavage by γ-secretase, and its intracellular portion (Notch intracellular domain, NICD) is released, translocates to the nucleus and exerts its function as a transcriptional regulator. The objective of this study was to determine whether the components of the Notch pathway are present in the CPCs of the adult mammalian heart and whether activation of the Notch-1 receptor promotes the differentiation of CPCs into myocytes. For this purpose, c-kit-positive CPCs were isolated from the mouse heart and analyzed by FACS and immunocytochemistry. Notch-1 receptor was detected in ~50% of c-kit-positive CPCs. CPCs were then plated on culture dishes coated with immobilized Jagged1 or Delta-4 and maintained in low-serum medium. Additional groups of cells were similarly exposed to the ligands but were also treated with γ-secretase inhibitor. After 5 days in culture, the number of CPCs was markedly lower in the presence of the Notch ligands and significantly higher in the presence of the γ-secretase inhibitor. After 8 days in culture, cells became confluent and did not express any longer c-kit. With respect to cells treated with the γ-secretase inhibitor, exposure to Jagged1 and Delta-4 resulted respectively in a 10-fold and 20-fold increase in the fraction of CPCs positive for Nkx2.5. These findings were consistent with a positive effect of Notch on CPC differentiation and Nkx2.5 upregulation. To establish whether Notch influenced cardiomyogenesis in vivo, infarcted mice were treated for 11 days with the γ-secretase inhibitor. The regenerative response of the infarcted heart, defined by the percentage of BrdU-positive myocytes distributed in the border zone, was 50% lower in animals that received the γ-secretase inhibitor. Thus, Notch1 modulates CPC differentiation in vitro and myocardial regeneration in vivo after infarction.

Fabrication of a Nanofibrous Scaffold for the In Vitro Culture of Cardiac Progenitor Cells for Myocardial Regeneration

2013 ◽  
Vol 63 (5) ◽  
pp. 229-239 ◽  
Author(s):  
Rouhollah Mehdinavaz Aghdam ◽  
Saeed Shakhesi ◽  
Siamak Najarian ◽  
Mona Malek Mohammadi ◽  
Seyed Hossein Ahmadi Tafti ◽  
...  
Keyword(s):  
In Vitro Culture ◽  
Progenitor Cells ◽  
Nanofibrous Scaffold ◽  
Myocardial Regeneration ◽  
Cardiac Progenitor Cells

scholarly journals Exercise promotes heart regeneration in aged rats by increasing regenerative factors in myocardial tissue

2020 ◽  
Vol 107 (1) ◽  
pp. 166-176
Author(s):  
A. Eskandari ◽  
R. Soori ◽  
S. Choobineh ◽  
Z. Mazaheri Tirani
Keyword(s):  
Progenitor Cells ◽  
Cell Activation ◽  
Mrna Level ◽  
Interval Training ◽  
Maximum Speed ◽  
Cardiac Progenitor Cells ◽  
Regenerative Capacity ◽  
Training Groups ◽  
Cardiovascular Regeneration ◽  
Male Wistar Rats

AbstractExercise‐induced stem cell activation is implicated in cardiovascular regeneration. However, ageing limits the capacity of cellular and molecular remodelling of the heart. It has been shown that exercise improves structure regeneration and function in the process of ageing. Aged male Wistar rats (n = 24) were divided into three groups: Control (CO), High-intensity interval training (HIIT) (80–100% of the maximum speed), and continuous endurance training (CET) (60–70% of the maximum speed) groups. Training groups were trained for 6 weeks. The expression of the Nkx2.5 gene was determined by real-time (RT-PCRs) analysis. Immunohistochemical staining was performed to assess the C-kit positive cardiac progenitor and Ki67 positive cells. The mRNA level of Nkx2.5 was significantly increased in the CET and HIIT groups (P < 0.05). Also, cardiac progenitor cells positive for C-kit were increased in both the CET and HIIT groups (P < 0.05). Exercise training improved the ejection fraction and fractional shortening in both training groups (P < 0.05). This study indicated that training initiates the activation of cardiac progenitor cells, leading to the generation of new myocardial cells (R = 0.737, P = 0.001). It seems that C-kit positive cells in training groups showed an increase in the expression of some transcription factors (Nkx2.5 gene), representing an increased regenerative capacity of cardiomyocytes during the training period. These findings suggest that the endogenous regenerative capacity of the adult heart, mediated by cardiac stem cells, would be increased in response to exercise.

Abstract 217: Long Non-coding RNA Myocardial Infarction-associated Transcript (MIAT) Protects Cardiac Progenitor Cells From Oxidative Stress-induced Cell Death

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Liu Yang ◽  
Yang Yu ◽  
Baron Arnone ◽  
Chan Boriboun ◽  
Jiawei Shi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Myocardial Infarction ◽  
Cell Death ◽  
Progenitor Cells ◽  
Cardiac Cells ◽  
Border Zone ◽  
Mouse Heart ◽  
Cardiac Progenitor Cells

Background: Long non-coding RNAs (lncRNAs) are an emerging class of RNAs with no or limited protein-coding capacity; a few of which have recently been shown to regulate critical biological processes. Myocardial infarction-associated transcript (MIAT) is a conserved mammalian lncRNA, and single nucleotide polymorphisms (SNPs) in 6 loci of this gene have been identified to be strongly associated with the incidence and severity of human myocardial infarction (MI). However, whether and how MIAT impacts on the pathogenesis of MI is unknown. Methods & Results: Quantitative RT-PCR analyses revealed that MIAT is expressed in neonatal mouse heart and to a lesser extent in adult heart. After surgical induction of MI in adult mice, MIAT starts to increase in 2 hours, peaks at 6 hours in atria and 12 hours in ventricles, and decreases to baseline at 24 hours. Fluorescent in situ hybridization (FISH) revealed a slight increase in the number of MIAT-expressing cells in the infarct border zone at 12 hours post-MI. Moreover, qRT-PCR analyses of isolated cardiac cells revealed that MIAT is predominantly expressed in cardiosphere-derived cardiac progenitor cells (CPCs). Treatment of CPCs with H 2 O 2 led to a marked upregulation of MIAT, while knockdown (KD) of MIAT resulted in a significantly impaired cell survival in vitro with H 2 O 2 treatment and in vivo after administered in the ischemic/reperfused heart. Notably, bioinformatics prediction and RNA immunoprecipitation identified FUS (fused in sarcoma) as a novel MIAT-interacting protein. FUS-KD CPCs displayed reduced cell viability and increased apoptosis under oxidative stress. Furthermore, MIAT overexpression enhanced survival of WT CPCs but not FUS-KD CPCs, suggesting that the protective role of MIAT is mediated by FUS. Conclusions: MIAT interacts with FUS to protect CPCs from oxidative stress-induced cell death.

An overview of the myocardial regeneration potential of cardiac c-Kit+ progenitor cells via PI3K and MAPK signaling pathways

2020 ◽  
Vol 16 (3) ◽  
pp. 199-209
Author(s):  
Ezzatollah Fathi ◽  
Behnaz Valipour ◽  
Ilja Vietor ◽  
Raheleh Farahzadi
Keyword(s):  
Progenitor Cells ◽  
Mapk Signaling ◽  
Myocardial Regeneration ◽  
Cardiac Progenitor Cells ◽  
Regeneration Potential ◽  
Innovative Strategy ◽  
Mapk Pathways ◽  
Cardiac Cell Therapy ◽  
Subsequent Activation ◽  
And Migration

In recent years, several studies have investigated cell transplantation as an innovative strategy to restore cardiac function following heart failure. Previous studies have also shown cardiac progenitor cells as suitable candidates for cardiac cell therapy compared with other stem cells. Cellular kit (c-kit) plays an important role in the survival and migration of cardiac progenitor cells. Like other types of cells, in the heart, cellular responses to various stimuli are mediated via coordinated pathways. Activation of c-kit+ cells leads to subsequent activation of several downstream mediators such as PI3K and the MAPK pathways. This review aims to outline current research findings on the role of PI3K/AKT and the MAPK pathways in myocardial regeneration potential of c-kit+.

Abstract 19220: Potential of Human Cardiac Progenitor Cells from Young versus Old Donor Hearts in Cardiac Protection against Ischemic Left Ventricular Dysfunction and Late Remodeling

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Ann Sophie Walravens ◽  
Ellen Caluwé ◽  
Sander Trenson ◽  
Hilde Gillijns ◽  
Nina Vanden Driessche ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Left Ventricular Dysfunction ◽  
Ventricular Dysfunction ◽  
Left Ventricular ◽  
Border Zone ◽  
Coronary Artery Ligation ◽  
Cardiac Progenitor Cells ◽  
Myocardial Repair ◽  
Old Patients ◽  
Expression Levels

Introduction: Recent discovery of c-Kit + resident cardiac progenitor cells (CPC) has demonstrated cardiac regenerative capacity, which is lost upon increasing age in mice. Accordingly, we hypothesized that c-KIT + -selected CPC from young human hearts (yCPC) have a greater myocardial repair potential after myocardial infarction (MI) than CPC from old patients (oCPC). Methods: After Ethics Committee approval, cardiac biopsies from young (1-15y old) and old (58-80y old) patients, undergoing corrective or valve surgery were obtained. After collagenase-based digestion, cells were culture-expanded for 2 passages prior to c-KIT + selection using magnetic beads. Purity was confirmed using qRT-PCR for c-KIT, GATA4, CD90, CD105, DDR2, CD31 and MYH11 expression levels. To trace transplanted cells, CPC were lentivirally tagged with GFP. After permanent LAD coronary artery ligation in immunodeficient mice, 250,000 CPCs were injected in the infarct border zone (4x 62,500 cells/2.5 μl; yCPC, n =8; oCPC, n =6; or PBS, n =6). Cardiac ultrasound (VisualSonics, 3D 30 MHz probe) was performed at baseline, 1 and 35 days after MI. At 35 days post-MI, infarct remodeling and cell survival was evaluated using Sirius red and CPC engraftment by anti-GFP staining. Results: In contrast to low MYH11 and CD31 expression levels, c-KIT and GATA4 were markedly and equally expressed in yCPC and oCPC, whereas transcript levels of DDR2, CD105 and CD90 were 89, 109 and 56% higher in oCPC compared to yCPC. Systolic function was better preserved in yCPC than in oCPC and PBS-treated mice 24h after MI (LVEF from baseline - D1: 53±1 - 38±3 vs. 52±3 - 30±5 vs. 50±3 - 27±4%; ESVi from baseline - D1: 3.7±0.2 - 5.1±0.4 vs. 3.8±0.5 - 6.2±0.7 vs. 3.9±0.5 - 6.5±0.6ml/mm 2 ). Moreover, after 35 days, the dilatory response was reduced in yCPC compared to oCPC and PBS-treated mice (EDVi from D1 - D35: 8.3±0.5 - 13.5±1.3 vs. 8.8±0.5 - 16.7±1.8 vs. 8.5±0.5 - 16.6±1.3ml/mm 2 ). Improved remodeling was consistent with a markedly greater rim of surviving myocardium while anti-GFP staining showed only rarely retained CPC. Conclusions: In summary, these findings suggest enhanced protection by c-KIT + CPC isolated from young donor hearts against acute systolic left ventricular dysfunction and late remodeling after MI.

Abstract 25: P2Y14 Purinergic Receptor Overexpression: Letting Blind Cardiac Progenitor Cells ’See’ Again

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Farid G Khalafalla ◽  
Waqas Kayani ◽  
Arwa Kassab ◽  
Kelli Ilves ◽  
Roberto J Alvarez ◽  
...  
Keyword(s):  
Stem Cells ◽  
Progenitor Cells ◽  
Molecular Mechanisms ◽  
Purinergic Receptor ◽  
Extracellular Nucleotides ◽  
Cardiac Progenitor Cells ◽  
Regenerative Capacity ◽  
Paracrine Factors ◽  
Poor Growth ◽  
Hematopoietic Stem

Heart failure (HF) is a leading cause of death due to limited regenerative capacity of adult mammalian heart following injury. Autologous stem cell therapy holds promise for promoting cardiac regeneration. However, stem cells derived from aged/diseased organs exhibit poor growth and survival capabilities. Empowering cardiac progenitor cells (CPC) with prosurvival genes has been attempted. Nonetheless, the molecular mechanisms by which stem cells initially detect stress signals to stimulate appropriate regenerative responses are poorly understood. This study aims to explore the physiological responses mediated by purinergic receptors, which represent a major detector for extracellular nucleotides released during injury/stress, with a focus on P2Y 14 nucleotide receptor (P2Y 14 R) activated by extracellular UDP-conjugated sugars. P2Y 14 R mediates proliferation of keratinocytes and chemotaxis of neutrophils and hematopoietic stem cells (HSCs). In addition, P2Y 14 R enhances HSC resistance to stress-induced senescence and maintains regenerative capacity after injury. However, the physiological roles of P2Y 14 R in CPCs are largely unknown. Preliminary data show striking correlations between P2Y 14 R expression in human CPCs derived from HF patients (hCPCs) and patients’ ejection fraction (EF), where low EF corresponds to low P2Y 14 R expression hCPCs. Moreover, hCPCs with relatively slower growth kinetics and enhanced senescence exhibit dramatic decreases in P2Y 14 R expression compared to fast-growing hCPCs. P2Y 14 R overexpression improves hCPC proliferation, migration, survival under stress stimuli and reverses senescent-associated phenotypes. Furthermore, P2Y 14 R-overexpressing hCPCs show remarkable upregulation in the expression of paracrine factors critical for cardiac repair. Preliminary studies will be extended in vivo to assess whether P2Y 14 R overexpression in hCPCs improves their reparative potential for injured mouse myocardium. Overall, this study introduces a novel interventional molecular approach to improve the therapeutic outcome of hCPCs by enhancing their capability to detect stress-induced extracellular nucleotides and initiate proper regenerative responses through augmenting P2Y 14 R expression.

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