scholarly journals Primate heart regeneration via migration and fibroblast repulsion by human heart progenitors

2020 ◽  
Author(s):  
Christine Schneider ◽  
Kylie S. Foo ◽  
Maria Teresa De Angelis ◽  
Gianluca Santamaria ◽  
Franziska Reiter ◽  
...  

SUMMARYHuman heart regeneration is one of the most critical unmet clinical needs at a global level1. Muscular regeneration is hampered both by the limited renewing capacity of adult cardiomyocytes2-4 and the onset of cardiac fibrosis5,6, resulting in reduced compliance of the tissue. Primate have proven to be ideal models for pluripotent stem cell strategies for heart regeneration, but unravelling specific approaches to drive cell migration to the site of injury and inhibition of subsequent fibrosis have been elusive. Herein, by combining human cardiac progenitor lineage tracing and single-cell transcriptomics in injured non-human primate heart bio-mimics, we uncover the coordinated muscular regeneration of the primate heart via directed migration of human ventricular progenitors to sites of injury, subsequent fibroblast repulsion targeting fibrosis, and ultimate functional replacement of damaged cardiac muscle by differentiation and electromechanical integration. Single-cell RNAseq captured distinct modes of action, uncovering chemoattraction mediated by CXCL12/CXCR4 signalling and fibroblast repulsion regulated by SLIT2/ROBO1 guidance in organizing cytoskeletal dynamics. Moreover, transplantation of human cardiac progenitors into hypo-immunogenic CAG-LEA29Y transgenic porcine hearts following injury proved their chemotactic response and their ability to generate a remuscularized scar without the risk of arrhythmogenesis in vivo. Our study demonstrates that inherent developmental programs within cardiac progenitors are sequentially activated in the context of disease, allowing the cells to sense and counteract injury. As such, they may represent an ideal bio-therapeutic for functional heart rejuvenation.

2020 ◽  
Author(s):  
Dennis E.M. de Bakker ◽  
Esther Dronkers ◽  
Mara Bouwman ◽  
Aryan Vink ◽  
Marie-José Goumans ◽  
...  

ABSTRACTRationaleThe human heart loses millions of cardiomyocytes after an ischemic injury, but is unable to regenerate the lost tissue. Instead, the injured human heart is repaired by pro-fibrotic fibroblasts that form a large permanent scar. In contrast, the injured zebrafish heart regenerates efficiently without the formation of a permanent scar. While fibroblasts have been shown to be indispensable for zebrafish heart regeneration, very little is known about the mechanisms balancing the fibrotic and regenerative response. A better understanding of these mechanisms could lead to the discovery of novel therapeutic strategies to reduce fibrosis and promote heart regeneration.ObjectiveTo identify novel mechanisms that regulate the balance between cardiac fibrosis and scar-free regeneration.Methods and ResultsUsing a genetic approach, we first show that zebrafish prrx1b loss-of-function mutants display reduced cardiomyocyte proliferation and impaired heart regeneration. Using a lineage tracing approach, we show that Prrx1b is expressed in tcf21+ epicardial-derived cells localizing around and inside the injured area. Next, we used a single cell RNA-sequencing approach on sorted tcf21+ cells isolated from injured prrx1b-/- and wild-type hearts and identified two distinct fibroblast populations. With combined bioinformatic and histological analysis we found that prrx1b-/- hearts contain an excess of pro-fibrotic fibroblasts that produce TGF-β ligands and collagens, while fewer pro-regenerative Nrg1-expressing fibroblasts are formed. Furthermore, by injecting recombinant NRG1 in prrx1b-/- fish we were able to rescue their cardiomyocyte proliferation defect. Finally, using cultured human fetal epicardial cells and siRNA mediated knock-down of PRRX1 we found that PRRX1 is required for NRG1 induction in human epicardial-derived cells.ConclusionsPrrx1b in the injured heart restricts fibrosis and stimulates regeneration by directing epicardial-derived cells towards a pro-regenerative Nrg1-producing fibroblast state.


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Haruko Nakano ◽  
Xiaoqian Liu ◽  
Armin Arshi ◽  
Ben van Handel ◽  
Rajkumar Sasidharan ◽  
...  

The circulatory system is the first functional organ system that develops during mammalian life. Accumulating evidences suggest that cardiac and endocardial cells can arise from a single common progenitor cell during mammalian cardiogenesis. Notably, these early cardiac progenitors express multiple hematopoietic transcription factors, consistent with previous reports. Indeed, a close relationship among cardiac, endocardial and hematopoietic lineages has been suggested in fly, zebrafish, and embryonic stem cell in vitro differentiation models. However, it is unclear when, where and how this hematopoietic gene program is in operation during in vivo mammalian cardiogenesis. Hematopoietic colony assay suggests that mouse heart explants generate myeloids and erythroids in the absence of circulation, suggesting that the heart tube is a de novo site for the definitive hematopoiesis. Lineage tracing revealed that putative cardiac-derived Nkx2-5+/Isl1+ endocardial cells give rise to CD41+ hematopoietic progenitors that contribute to definitive hematopoiesis in vivo and ex vivo during embryogenesis earlier than in the AGM region. Furthermore, Nkx2-5 and Isl1 are both required for the hemogenic activity of the endocardium. Together, identification of Nkx2-5/Isl1-dependent hemogenic endocardial cells (1) adds hematopoietic component in the cardiogenesis lineage tree, (2) changes the long-held dogma that AGM is the only major source of definitive hematopoiesis in the embryo proper, and (3) represents phylogenetically conserved fundamental mechanism of cardio-vasculo-hematopoietic differentiation pathway during the development of circulatory system.


2020 ◽  
Vol 82 (1) ◽  
pp. 63-78 ◽  
Author(s):  
Michelle D. Tallquist

Cardiac fibrosis is a pathological condition that occurs after injury and during aging. Currently, there are limited means to effectively reduce or reverse fibrosis. Key to identifying methods for curbing excess deposition of extracellular matrix is a better understanding of the cardiac fibroblast, the cell responsible for collagen production. In recent years, the diversity and functions of these enigmatic cells have been gradually revealed. In this review, I outline current approaches for identifying and classifying cardiac fibroblasts. An emphasis is placed on new insights into the heterogeneity of these cells as determined by lineage tracing and single-cell sequencing in development, adult, and disease states. These recent advances in our understanding of the fibroblast provide a platform for future development of novel therapeutics to combat cardiac fibrosis.


2016 ◽  
Vol 113 (43) ◽  
pp. 12192-12197 ◽  
Author(s):  
Jared M. Fischer ◽  
Peter P. Calabrese ◽  
Ashleigh J. Miller ◽  
Nina M. Muñoz ◽  
William M. Grady ◽  
...  

Intestinal stem cells (ISCs) are maintained by a niche mechanism, in which multiple ISCs undergo differential fates where a single ISC clone ultimately occupies the niche. Importantly, mutations continually accumulate within ISCs creating a potential competitive niche environment. Here we use single cell lineage tracing following stochastic transforming growth factor β receptor 2 (TgfβR2) mutation to show cell autonomous effects of TgfβR2 loss on ISC clonal dynamics and differentiation. Specifically, TgfβR2 mutation in ISCs increased clone survival while lengthening times to monoclonality, suggesting that Tgfβ signaling controls both ISC clone extinction and expansion, independent of proliferation. In addition, TgfβR2 loss in vivo reduced crypt fission, irradiation-induced crypt regeneration, and differentiation toward Paneth cells. Finally, altered Tgfβ signaling in cultured mouse and human enteroids supports further the in vivo data and reveals a critical role for Tgfβ signaling in generating precursor secretory cells. Overall, our data reveal a key role for Tgfβ signaling in regulating ISCs clonal dynamics and differentiation, with implications for cancer, tissue regeneration, and inflammation.


2020 ◽  
Author(s):  
Kenzo Ivanovitch ◽  
Pablo Soro-Barrio ◽  
Probir Chakravarty ◽  
Rebecca A Jones ◽  
S. Neda Mousavy Gharavy ◽  
...  

AbstractThe heart develops from two sources of mesoderm progenitors, the first and second heart field (FHF and SHF). Using a single cell transcriptomic assay in combination with genetic lineage tracing, we find the FHF and SHF are subdivided into distinct pools of progenitors in gastrulating mouse embryos at earlier stages than previously thought. Each subpopulation has a distinct origin in the primitive streak. The first progenitors to leave the primitive streak contribute to the left ventricle, shortly after right ventricle progenitor emigrate, followed by the outflow tract and atrial progenitors. Although cells allocated to the outflow tract and atrium leave the primitive streak at a similar stage, they arise from different regions. Outflow tract originate from distal locations in the primitive streak while atrial progenitors are positioned more proximally. Moreover, single cell RNA sequencing demonstrates that the primitive streak cells contributing to the ventricles have a distinct molecular signature from those forming the outflow tract and atrium. We conclude that cardiac progenitors are pre-patterned within the primitive streak and this prefigures their allocation to distinct anatomical structures of the heart. Together, our data provide a new molecular and spatial map of mammalian cardiac progenitors that will support future studies of heart development, function and disease.


PLoS Biology ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. e3001200
Author(s):  
Kenzo Ivanovitch ◽  
Pablo Soro-Barrio ◽  
Probir Chakravarty ◽  
Rebecca A. Jones ◽  
Donald M. Bell ◽  
...  

The heart develops from 2 sources of mesoderm progenitors, the first and second heart field (FHF and SHF). Using a single-cell transcriptomic assay combined with genetic lineage tracing and live imaging, we find the FHF and SHF are subdivided into distinct pools of progenitors in gastrulating mouse embryos at earlier stages than previously thought. Each subpopulation has a distinct origin in the primitive streak. The first progenitors to leave the primitive streak contribute to the left ventricle, shortly after right ventricle progenitor emigrate, followed by the outflow tract and atrial progenitors. Moreover, a subset of atrial progenitors are gradually incorporated in posterior locations of the FHF. Although cells allocated to the outflow tract and atrium leave the primitive streak at a similar stage, they arise from different regions. Outflow tract cells originate from distal locations in the primitive streak while atrial progenitors are positioned more proximally. Moreover, single-cell RNA sequencing demonstrates that the primitive streak cells contributing to the ventricles have a distinct molecular signature from those forming the outflow tract and atrium. We conclude that cardiac progenitors are prepatterned within the primitive streak and this prefigures their allocation to distinct anatomical structures of the heart. Together, our data provide a new molecular and spatial map of mammalian cardiac progenitors that will support future studies of heart development, function, and disease.


2020 ◽  
Author(s):  
Jenny A.F. Vermeer ◽  
Jonathan Ient ◽  
Bostjan Markelc ◽  
Jakob Kaeppler ◽  
Lydie M.O. Barbeau ◽  
...  

AbstractIntratumoural hypoxia is a common characteristic of malignant treatment-resistant cancers. However, hypoxia-modification strategies for the clinic remain elusive. To date little is known on the behaviour of individual hypoxic tumour cells in their microenvironment. To explore this issue in a spatial and temporally-controlled manner we developed a genetically encoded sensor by fusing the O2-labile Hypoxia-Inducible Factor 1α to eGFP and a tamoxifen-regulated Cre recombinase. Under normoxic conditions HIF-1α is degraded but under hypoxia, the HIF-1α-GFP-Cre-ERT2 fusion protein is stabilised and in the presence of tamoxifen activates a tdTomato reporter gene that is constitutively expressed in hypoxic progeny. We visualise the random distribution of hypoxic tumour cells from hypoxic or necrotic regions and vascularised areas using immunofluorescence and intravital microscopy. Once tdTomato expression is induced, it is stable for at least 4 weeks. Using this system, we could show that the post-hypoxic cells were more proliferative in vivo than non-labelled cells. Our results demonstrate that single-cell lineage tracing of hypoxic tumour cells can allow visualisation of their behaviour in living tumours using intravital microscopy. This tool should prove valuable for the study of dissemination and treatment response of post-hypoxic tumour cells in vivo at single-cell resolution.Summary StatementHere we developed and characterised a novel HIF-1α-Cre fusion gene to trace the progeny of hypoxic tumour cells in a temporal and spatially resolved manner using intravital microscopy.


2020 ◽  
Author(s):  
Kristen L. Wells ◽  
Corey N. Miller ◽  
Andreas R. Gschwind ◽  
Wu Wei ◽  
Jonah D. Phipps ◽  
...  

AbstractMedullary thymic epithelial cells (mTECs) play a critical role in central immune tolerance by mediating negative selection of autoreactive T cells through the collective expression of the peripheral self-antigen compartment, including tissue-specific antigens (TSAs). Recent work has shown that gene expression patterns within the mTEC compartment are remarkably heterogenous and include multiple differentiated cell states. To further define mTEC development and medullary epithelial lineage relationships, we combined lineage tracing and recovery from transient in vivo mTEC ablation with single cell RNA-sequencing. The combination of bioinformatic and experimental approaches revealed a non-stem transit-amplifying population of cycling mTECs that preceded Aire expression. Based on our findings, we propose a branching model of mTEC development wherein a heterogeneous pool of transit-amplifying cells gives rise to Aire- and Ccl21a-expressing mTEC subsets. We further use experimental techniques to show that within the Aire-expressing developmental branch, TSA expression peaked as Aire expression decreased, implying Aire expression must be established before TSA expression can occur. Collectively, these data provide a higher order roadmap of mTEC development and demonstrate the power of combinatorial approaches leveraging both in vivo models and high-dimensional datasets.


Author(s):  
Shaohua Zhang ◽  
Yan Li ◽  
Xiuzhen Huang ◽  
Kuo Liu ◽  
Qing-Dong Wang ◽  
...  

Background: Cardiac fibrosis is a lethal outcome of excessive formation of myofibroblasts that are scar-forming cells accumulated after heart injury. It has been reported that cardiac endothelial cells (ECs) contribute to a substantial portion of myofibroblasts through EndoMT. Recent lineage tracing studies demonstrate that myofibroblasts are derived from expansion of resident fibroblasts rather than from transdifferentiation of ECs. However, it remains unknown whether ECs can transdifferentiate into myofibroblasts reversibly or EndoMT genes were just transiently activated in ECs during cardiac fibrosis. Methods: By using the dual recombination technology based on Cre-loxP and Dre-rox, we generated a genetic lineage tracing system for tracking EndoMT in cardiac ECs. We used it to examine if there is transiently activated mesenchymal gene expression in ECs during cardiac fibrosis. Activation of the broadly used marker gene in myofibroblasts, αSMA, and the transcription factor that induces epithelial to mesenchymal transition (EMT), Zeb1, was examined. Results: The genetic system enables continuous tracing of transcriptional activity of targeted genes in vivo . Our genetic fate mapping results revealed that a subset of cardiac ECs transiently expressed αSMA and Zeb1 during embryonic valve formation and transdifferentiated into mesenchymal cells through EndoMT. Nonetheless, they did not contribute to myofibroblasts; nor transiently expressed αSMA or Zeb1 after heart injury. Instead, expression of αSMA was activated in resident fibroblasts during cardiac fibrosis. Conclusions: Mesenchymal gene expression is activated in cardiac ECs through EndoMT in the developing heart; but ECs do not transdifferentiate into myofibroblasts, nor transiently express some known mesenchymal genes during homeostasis and fibrosis in the adult heart. Resident fibroblasts that are converted to myofibroblasts by activating mesenchymal gene expression are the major contributors to cardiac fibrosis.


2021 ◽  
Author(s):  
Kai Miao ◽  
Aiping Zhang ◽  
Fangyuan Shao ◽  
Lijian Wang ◽  
Xin Zhang ◽  
...  

Abstract Cancer metastasis is the primary cause of cancer-related death, yet the forces that drive cancer cells through various steps and different routes to distinct target organs/tissues remain elusive. In this study, we applied a CellTag system-based single-cell lineage tracing approach to show the metastasis rate and route of breast cancer cells and their interactions with the tumour microenvironment (TME) during metastasis. The results indicate that only a small fraction of cells can intravasate from the primary site into the blood circulation, whereas more cells disseminate through the lymphatic system to different organs. Tumour cells derived from the same progenitor cell exhibit different gene expression patterns in different soils, and the cancer cell-TME communication paradigm varies significantly between primary and metastatic tumours. Furthermore, metastable cells require a prewired IL-2 expression ability to migrate in vivo. In summary, leveraging a single-cell lineage tracing system, we demonstrate that the crosstalk between tumour cells and the TME is the driving force controlling the preferential metastatic fate of cancer cells through the lymphatic system and that this metastasis can be suppressed by knockdown of IL-2.


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