Abstract 173: Clonal Analysis Reveals Limited Proliferative Capacity of Mature Cardiomyocytes during Embryonic Development.

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Konstantina-Ioanna Sereti ◽  
Paniz Kamran ◽  
Shah R Ali ◽  
Josh Z Lee ◽  
Ali Subat ◽  
...  
Keyword(s):  
Clonal Expansion ◽  
Clonal Analysis ◽  
Cardiac Cells ◽  
Cell Labeling ◽  
Postnatal Life ◽  
Cardiovascular Development ◽  
Reporter System ◽  
Cellular Mechanisms ◽  
Cardiac Progenitors ◽  
Time Points

There is growing evidence that supports the ability of the heart to generate new cardiomyocytes during development and in response to injury albeit at a very low rate. It still remains unclear whether the newly generated cells originate from cardiac progenitor/stem cells or from pre-existing cardiomyocytes that re-enter the cell cycle. Understanding the cellular mechanisms regulating new cardiomyocyte formation is imperative towards the development of novel clinical strategies. We assessed the hypothesis that the cardiomyocytes generated during cardiac development are derived from cardiac progenitor cells and to a lesser extent form proliferating cardiomyocytes. We performed clonal analysis of cardiomyocyte formation by utilizing a stochastic multicolor reporter system (Rainbow) that allows random labeling of cells with three fluorescent proteins upon Cre-mediated recombination. Rainbow mice were crossed to αMHC-CreER mice for selective marking of cardiomyocytes or to Actin-CreER mice where all types of cells can be labeled. We induced rare recombination events at embryonic day E12.5 and clonal expansion of labeled cells was retrospectively analyzed at different time-points from E15.5 to postnatal day P30. To determine at which developmental stage cardiac cells lose their ability to proliferate, recombination was induced at different time-points from early embryonic to postnatal life and analysis was performed at P30. For each time-point, data was collected from ten mice. In αMHC-CreER;Rainbow mice, we observed mainly single cell labeling, a few doublets and some rare four-cell clones. At the same time-points, Actin-CreER;Rainbow hearts exhibited a large number of clones ranging from doublets to clones of more than twenty cells. Interestingly, clone formation and expansion was reduced with age. In conclusion, our results indicate that αMHC-positive cardiomyocyte proliferation is limited during development. On the other hand, non-αMHC expressing cells exhibited clonal expansion suggesting the possible contribution of cardiac progenitors even during late cardiovascular development.

Abstract 257: Clonal Analysis Of Multipotent Cardiovascular Progenitors That Generate Cardiomyocytes During Development

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Konstantina Ioanna Sereti ◽  
Paniz Kamran Rashani ◽  
Peng Zhao ◽  
Reza Ardehali
Keyword(s):  
Single Cell ◽  
Heart Development ◽  
Cardiac Development ◽  
Clonal Analysis ◽  
Cardiac Cells ◽  
Single Cell Level ◽  
Reporter System ◽  
Cell Level ◽  
Cardiac Progenitors

It has been proposed that cardiac development in lower vertebrates is driven by the proliferation of cardiomyocytes. Similarly, cycling myocytes have been suggested to direct cardiac regeneration in neonatal mice after injury. Although, the role of cardiomyocyte proliferation in cardiac tissue generation during development has been well documented, the extent of this contribution as well as the role of other cell types, such as progenitor cells, still remains controversial. Here we used a novel stochastic four-color Cre-dependent reporter system (Rainbow) that allows labeling at a single cell level and retrospective analysis of the progeny. Cardiac progenitors expressing Mesp1 or Nkx2.5 were shown to be a source of cardiomyocytes during embryonic development while the onset of αMHC expression marked the developmental stage where the capacity of cardiac cells to proliferate diminishes significantly. Through direct clonal analysis we provide strong evidence supporting that cardiac progenitors, as opposed to mature cardiomyocytes, are the main source of cardiomyocytes during cardiac development. Moreover, we have identified quadri-, tri-, bi, and uni-potent progenitors that at a single cell level can generate cardiomyocytes, fibroblasts, endothelial and smooth muscle cells. Although existing cardiomyocytes undergo limited proliferation, our data indicates that it is mainly the progenitors that contribute to heart development. Furthermore, we show that the limited proliferation capacity of cardiomyocytes observed during normal development was enhanced following neonatal cardiac injury allowing almost complete regeneration of the scared tissue. However, this ability was largely absent in adult injured hearts. Detailed characterization of dividing cardiomyocytes and proliferating progenitors would greatly benefit the development of novel therapeutic options for cardiovascular diseases.

scholarly journals The Hypothalamic-Pituitary-Thyroid Axis in Preterm Infants; Changes in the First 24 Hours of Postnatal Life

2004 ◽  
Vol 89 (6) ◽  
pp. 2824-2831 ◽  
Author(s):  
Nuala Murphy ◽  
Robert Hume ◽  
Hans van Toor ◽  
Tom G. Matthews ◽  
Simon A. Ogston ◽  
...  
Keyword(s):  
Preterm Infants ◽  
Age Groups ◽  
Postnatal Life ◽  
Free T4 ◽  
Thyroxine Binding Globulin ◽  
Time Points ◽  
Pituitary Thyroid Axis ◽  
Serum T4 ◽  
Thyroid Axis ◽  
Immature Group

Abstract The purpose of this study was to measure serum T4, free T4, TSH, T3, rT3, T4 sulfate, and thyroxine binding globulin at four time points within the first 24 h of life (cord and 1, 7, and 24 h) in infants between 24 and 34 wk gestation. The infants were subdivided into gestational age groups: 24–27 wk (n = 22); 28–30 wk (n = 26); and 31–34 wk (n = 24). The TSH surge in the first hour of postnatal life was markedly attenuated in infants of 24–27 wk gestation [8 compared with 20 (28–30 wk) and 23 mU/liter (31–34 wk)]. T4 levels in the most immature group declined over the first 24 h, whereas levels increased in the more mature groups [mean cord and 24-h levels: 65 and 59 (NS) vs. 70 and 84 (P < 0.002) vs. 98 and 125 (NS) nmol/liter]. Free T4 and T3 showed only small, transient increases in the most immature group and progressively larger and sustained increases in the other gestational groups. rT3 and T4 sulfate levels in cord serum were higher in the most immature infants, and in all groups levels decreased initially and then variably increased. The features of a severely attenuated or failed hypothalamic-pituitary-thyroid response to delivery critically define this 24- to 27-wk group as distinct from more mature preterm infants.

Abstract 304: Efficient Generation of Cardiac Purkinje Fiber-like Cells From ESCs by Activating cAMP Signaling

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Su-Yi Tsai ◽  
Karen Maass ◽  
Jia Lu ◽  
Glenn I Fishman ◽  
Shuibing Chen ◽  
...  
Keyword(s):  
Embryonic Stem ◽  
Cardiac Cells ◽  
Cardiac Conduction ◽  
Camp Signaling ◽  
Purkinje Fiber ◽  
Mechanistic Studies ◽  
Cardiac Progenitors ◽  
Gene Profiles ◽  
Novel Strategy ◽  
Regenerative Therapies

Dysfunction of the cardiac conduction system (CCS) significantly impacts pathogenesis of arrhythmia, a major cause of morbidity and mortality. Strategies to derive cardiac conduction cells including Purkinje fiber cells (PC) would facilitate models for mechanistic studies and drug discovery, and also provide new cellular materials for regenerative therapies. A high-throughput chemical screen using CCS:lacZ and Contactin2:eGFP (Cntn2:eGFP) reporter embryonic stem cell (ESC) lines was used to discover a small molecule, sodium nitroprusside (SN), that efficiently promotes the generation of cardiac cells that express gene profiles and generate action potentials of PC-like cells. Imaging and mechanistic studies suggest that SN promotes the generation of PC from cardiac progenitors initially expressing cardiac myosin heavy chain, and that it does so by activating cAMP signaling. These findings provide a novel strategy to derive scalable PC, along with insight into the ontogeny of CCS development.

scholarly journals Applications of miRNAs in cardiac development, disease progression and regeneration

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jeremy Kah Sheng Pang ◽  
Qian Hua Phua ◽  
Boon-Seng Soh
Keyword(s):  
Cardiac Development ◽  
Control Cell ◽  
Proliferative Potential ◽  
Heart Cells ◽  
Cardiovascular Development ◽  
Developmental Defects ◽  
Protein Coding ◽  
Cardiac Progenitors ◽  
Multiple Levels ◽  
Cell Niche

AbstractDevelopment of the complex human heart is tightly regulated at multiple levels, maintaining multipotency and proliferative state in the embryonic cardiovascular progenitors and thereafter suppressing progenitor characteristics to allow for terminal differentiation and maturation. Small regulatory microRNAs (miRNAs) are at the level of post-transcriptional gene suppressors, which enhance the degradation or decay of their target protein-coding mRNAs. These miRNAs are known to play roles in a large number of biological events, cardiovascular development being no exception. A number of critical cardiac-specific miRNAs have been identified, of which structural developmental defects have been linked to dysregulation of miRNAs in the proliferating cardiac stem cells. These miRNAs present in the stem cell niche are lost when the cardiac progenitors terminally differentiate, resulting in the postnatal mitotic arrest of the heart. Therapeutic applications of these miRNAs extend to the realm of heart failure, whereby the death of heart cells in the ageing heart cannot be replaced due to the arrest of cell division. By utilizing miRNA therapy to control cell cycling, the regenerative potential of matured myocardium can be restored. This review will address the various cardiac progenitor-related miRNAs that control the development and proliferative potential of the heart.

scholarly journals Cardiac Transmembrane Ion Channels and Action Potentials: Cellular Physiology and Arrhythmogenic Behavior

2020 ◽  
Author(s):  
András Varró ◽  
Jakub Tomek ◽  
Norbert Nagy ◽  
Laszlo Virag ◽  
Elisa Passini ◽  
...  
Keyword(s):  
Ion Channel ◽  
Action Potentials ◽  
Cardiac Electrophysiology ◽  
Current Knowledge ◽  
Animal Experiments ◽  
Cardiac Cells ◽  
Cellular Mechanisms ◽  
Electrophysiological Properties ◽  
Channel Expression ◽  
Ionic Mechanisms

Cardiac arrhythmias are among the leading causes of mortality. They often arise from alterations in the electrophysiological properties of cardiac cells, and their underlying ionic mechanisms. It is therefore critical to further unravel the patho-physiology of the ionic basis of human cardiac electrophysiology in health and disease. In the first part of this review, current knowledge on the differences in ion channel expression and properties of the ionic processes that determine the morphology and properties of cardiac action potentials and calcium dynamics from cardiomyocytes in different regions of the heart are described. Then the cellular mechanisms promoting arrhythmias in congenital or acquired conditions of ion channel function (electrical remodelling) are discussed. The focus is human relevant findings obtained with clinical, experimental and computational studies, given that interspecies differences make the extrapolation from animal experiments to the human clinical settings difficult. Deepening the understanding of the diverse patholophysiology of human cellular electrophysiology will help developing novel and effective antiarrhythmic strategies for specific subpopulations and disease conditions.

LEOPARD-type SHP2 mutant Gln510Glu attenuates cardiomyocyte differentiation and promotes cardiac hypertrophy via dysregulation of Akt/GSK-3β/β-catenin signaling

2011 ◽  
Vol 301 (4) ◽  
pp. H1531-H1539 ◽  
Author(s):  
Hidekazu Ishida ◽  
Shigetoyo Kogaki ◽  
Jun Narita ◽  
Hiroaki Ichimori ◽  
Nobutoshi Nawa ◽  
...  
Keyword(s):  
Late Stage ◽  
Fluorescent Protein ◽  
Glycogen Synthase ◽  
Morphological Changes ◽  
Cardiac Cells ◽  
The Other ◽  
Cardiomyocyte Differentiation ◽  
Cardiac Progenitors ◽  
P19cl6 Cells ◽  
Gsk 3Β

LEOPARD syndrome (LS) is an autosomal dominant inherited multisystemic disorder. Most cases involve mutations in the PTPN11 gene, which encodes the protein tyrosine phosphatase Src homology 2-containing protein phosphatase 2 (SHP2). LS frequently causes severe hypertrophic cardiomyopathy (HCM), even from the fetal period. However, the molecular pathogenesis has not been clearly elucidated. Here, we analyzed the roles of the LS-type SHP2 mutant Gln510Glu (Q510E), which showed the most severe type of HCM in LS, in cardiomyocyte differentiation, and in morphological changes. We generated mutant P19CL6 cell lines, the most convenient cardiomyocyte differentiation model, which continuously expressed SHP2-Q510E, SHP2-D61N (Noonan-type mutant), wild-type SHP2, and green fluorescent protein (native SHP2 expression only). SHP2-Q510E mutant P19CL6 cells showed significant attenuation of myofibrillogenesis, with increased proliferative activity. Mature cardiomyocytes from the SHP2-Q510E mutant were significantly larger than those of controls and the other mutants. However, expression of cardiac-specific transcriptional factors (Gata4, Tbx5, and Nkx2.5) did not differ significantly between the LS-type SHP2-Q510E mutants and the other mutants and controls. Our results indicate that SHP2-Q510E mutants can differentiate into cardiac progenitors but are inhibited from undergoing terminal differentiation into mature cardiomyocytes. In contrast, Akt and glycogen synthase kinase (GSK)-3β phosphorylation were upregulated, and nuclear β-catenin at the late stage of differentiation was highly accumulated in SHP2-Q510E mutant P19CL6 cells. Supplementation with the phosphoinositide 3-kinase/Akt inhibitor LY-294002 during the late stage of differentiation was found to partially restore myofibrillogenesis while suppressing the increase in size of individual mature cardiomyocytes derived from the SHP2-Q510E mutants. Our findings suggest that dysregulation of the Akt/GSK-3β/β-catenin pathway can contribute to the pathogenesis of HCM in LS patients, not only through hypertrophic changes in individual cardiac cells but also via the expansion of cardiac progenitors.

scholarly journals Precardiac deletion of Numb and Numblike reveals renewal of cardiac progenitors

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Lincoln T Shenje ◽  
Peter Andersen ◽  
Hideki Uosaki ◽  
Laviel Fernandez ◽  
Peter P Rainer ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Cell Fate ◽  
Cardiac Cells ◽  
Cardiac Progenitor Cells ◽  
Pharyngeal Arches ◽  
Cardiac Progenitors ◽  
Intrinsic Factors ◽  
Flow Cytometric ◽  
Functional Analyses

Cardiac progenitor cells (CPCs) must control their number and fate to sustain the rapid heart growth during development, yet the intrinsic factors and environment governing these processes remain unclear. Here, we show that deletion of the ancient cell-fate regulator Numb (Nb) and its homologue Numblike (Nbl) depletes CPCs in second pharyngeal arches (PA2s) and is associated with an atrophic heart. With histological, flow cytometric and functional analyses, we find that CPCs remain undifferentiated and expansive in the PA2, but differentiate into cardiac cells as they exit the arch. Tracing of Nb- and Nbl-deficient CPCs by lineage-specific mosaicism reveals that the CPCs normally populate in the PA2, but lose their expansion potential in the PA2. These findings demonstrate that Nb and Nbl are intrinsic factors crucial for the renewal of CPCs in the PA2 and that the PA2 serves as a microenvironment for their expansion.

scholarly journals CLARA: A web portal for interactive exploration of the cardiovascular cellular landscape in health and disease

2021 ◽  
Author(s):  
Malathi S.I. Dona ◽  
Ian Hsu ◽  
Thushara S Rathnayake ◽  
Gabriella E. Farrugia ◽  
Taylah L Gaynor ◽  
...  
Keyword(s):  
Single Cell ◽  
Web Application ◽  
Rapid Development ◽  
Expression Patterns ◽  
Cardiac Cells ◽  
Ease Of Use ◽  
Molecular Networks ◽  
Cardiovascular Development ◽  
Web Portal ◽  
Cellular Phenotypes

Mammalian cardiovascular tissues are comprised of complex and diverse collections of cells. Recent advances in single-cell profiling technologies have accelerated our understanding of tissue cellularity and the molecular networks that orchestrate cardiovascular development, maintain homeostasis, and are disrupted in pathological states. Despite the rapid development and application of these technologies, many cardiac single-cell functional genomics datasets remain inaccessible for most cardiovascular biologists. Access to custom visual representations of the data, including querying changes in cellular phenotypes and interactions in diverse contexts, remains unavailable in publicly accessible data portals. Visualizing data is also challenging for scientists without expertise in processing single-cell genomic data. Here we present CLARA—CardiovascuLAR Atlas—a web portal facilitating exploration of the cardiovascular cellular landscape. Using mouse and human single-cell transcriptomic datasets, CLARA enables scientists unfamiliar with single-cell-omic data analysis approaches to examine gene expression patterns and the cell population dynamics of cardiac cells in a range of contexts. The web-application also enables investigation of intercellular interactions that form the cardiac cellular niche. CLARA is designed for ease-of-use and we anticipate that the portal will aid deeper exploration of cardiovascular cellular landscapes in the context of development, homeostasis and disease. CLARA is freely available at https://clara.baker.edu.au.

Effect of chimeric antigen receptor (CAR) T cells on clonal expansion of endogenous non-CAR T cells in patients (pts) with advanced solid cancer.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 3011-3011 ◽  
Author(s):  
Rebecca H Kim ◽  
Gabriela Plesa ◽  
Whitney Gladney ◽  
Irina Kulikovskaya ◽  
Bruce L Levine ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Clonal Expansion ◽  
Time Points ◽  
Cell Product ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Vaccine Effect

3011 Background: CAR T cells have produced remarkable responses in heme malignancies, but efficacy in solid cancers is limited. Poor in vivo persistence and heterogeneous expression of the CAR target on tumors are potential barriers to the success of CAR T cell therapy. However, even with transient persistence, CAR T cells may elicit a “vaccine” effect by inducing cancer cell death and subsequent release of tumor antigens that could stimulate tumor-specific T cell activity. Methods: 6 pts with pancreatic ductal adenocarcinoma (PDAC) received repeated 3x per week intravenous (iv) infusions of mRNA-transfected mesothelin-redirected CAR T cells (CARTmeso). Pts with PDAC (n = 5), ovarian carcinoma (n = 5), and mesothelioma (n = 5) received iv infusion of lentiviral-transduced (lenti) CARTmeso with or without cyclophosphamide (Cy) preconditioning. Peripheral blood samples were collected from pts at baseline and defined time points after treatment. Genomic DNA from these samples or from pre-infused CAR T cell product was used for deep sequencing of the TCRbeta chain using the ImmunoSEQ platform. A TCRbeta clone was considered to have expanded from baseline to defined time points after treatment if it showed a two-fold change from baseline and met statistical significance by Fisher’s exact test (p < 0.05). Results: mRNA CARTmeso cells persisted in vivo for < 24 hrs. Unexpectedly, therapy induced clonal T cell expansion detected in the blood by day 14 in all 6 pts. Expanded clones underwent contraction by day 28 in 3 pts. In one pt, peripherally expanded clones were also detected in a tumor biopsy, but without significant intratumoral clonal expansion. Lenti CARTmeso therapy also induced peripheral expansion of T cell clones both present and not present in the infused CAR T cell product. However, with Cy preconditioning, clonal expansion seen after lenti CARTmeso therapy was predominately restricted to clones detected in the CAR T cell product. Conclusions: In pts with advanced solid cancers, CARTmeso stimulates clonal expansion of endogenous T cells, which is lost with Cy conditioning. Findings suggest that CAR T cells may elicit a “vaccine” effect with potential therapeutic implications.

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