Project description:Neurons derived from human pluripotent stem cells (hPSCs) are a remarkable tool for modeling human neural development and diseases. However, it remains largely unknown whether the hPSC-derived neurons can be functionally coupled with their target tissues in vitro, which is essential for understanding inter-cellular physiology and further translational studies. Here, we demonstrate that hPSC-derived sympathetic neurons can be obtained from hPSCs and that the resulting neurons form physical and functional connections with cardiac muscle cells. By use of multiple hPSC reporter lines, we recapitulated human autonomic neuron development in vitro, and successfully isolated PHOX2B::eGFP+ neurons exhibiting sympathetic marker expression, electrophysiological properties, and norepinephrine secretion. With pharmacological and optogenetic manipulations, the PHOX2B::eGFP+ neurons controlled the beating rates of cardiomyocytes, and their physical interaction led to neuronal maturation. Our study lays a foundation for the specification of human sympathetic neurons and for the hPSC-based neuronal control of end organs in a dish. Using the four genetic reporter systems (OCT4::eGFP, SOX10::eGFP, ASCL1::eGFP, and PHOX2B::eGFP reporter hESC lines), we were able to purify discrete cell populations at four differentiation stages, recapitulating the sympathoadrenal differentiation process in vitro with purified and defined populations in four specific differentiation stages. We performed transcriptome analysis of OCT4::eGFP+ cells (3 biological replicates, representing undifferentiated hESCs), SOX10::eGFP+ cells (3 biological replicates, multi-potent neural crest), ASCL1::eGFP+ cells (3 biological replicates, putative sympathoadrenal progenitors), and PHOX2B::eGFP+ cells (2 biological replicates, putative sympathetic neuronal precursors).
Project description:Neurons derived from human pluripotent stem cells (hPSCs) are a remarkable tool for modeling human neural development and diseases. However, it remains largely unknown whether the hPSC-derived neurons can be functionally coupled with their target tissues in vitro, which is essential for understanding inter-cellular physiology and further translational studies. Here, we demonstrate that hPSC-derived sympathetic neurons can be obtained from hPSCs and that the resulting neurons form physical and functional connections with cardiac muscle cells. By use of multiple hPSC reporter lines, we recapitulated human autonomic neuron development in vitro, and successfully isolated PHOX2B::eGFP+ neurons exhibiting sympathetic marker expression, electrophysiological properties, and norepinephrine secretion. With pharmacological and optogenetic manipulations, the PHOX2B::eGFP+ neurons controlled the beating rates of cardiomyocytes, and their physical interaction led to neuronal maturation. Our study lays a foundation for the specification of human sympathetic neurons and for the hPSC-based neuronal control of end organs in a dish.
Project description:hPSC-CM has been used to model cardiac-related disease phenotypes. However, the immaturity of hPSC-CM constrains their potential in cell-based therapy, disease modeling and drug discovery. To understand the molecular mechanism driving human PSC-CM maturation, we utilized a metabolic reporter cell line that allows for the purification of CM that reflects different physiological status (fetal-like or matured). To identify transcription factors and pathways that enhances CM maturation, bulk RNA sequencing was performed on low-GFP expressing matured CM and high-GFP expressing fetal-like CM. The results revealed up-regulated expression of pathways involved in interferon signaling and down-regulation of pathways related to cell cycle checkpoints.
Project description:Rationale: Human pluripotent stem cells-derived cardiomyocytes (hPSC-CMs) exhibit the properties of fetal CMs, which limit their applications. Various methods have been used to promote maturation of hPSC-CMs; however, there is a lack of an unbiased and comprehensive method for accurate benchmarking of hPSC-CM maturation.
Objective: We aim to develop an unbiased proteomics method integrating high-throughput top-down targeted proteomics and bottom-up global proteomics for accurate and comprehensive assessment of hPSC-CM maturation.
Methods and Results: Utilizing hPSC-CMs from early- and late-stage two-dimensional monolayer culture and three-dimensional engineered cardiac tissue, we demonstrated high reproducibility and reliability of the top-down proteomics method, which enabled simultaneous quantification of contractile protein isoform expressions and their PTMs. This method allowed for the detection of known maturation-associated contractile protein alterations, and for the first time, identified contractile protein PTMs as promising new markers of maturation. By employing a global proteomics strategy, we identified candidate maturation markers important for sarcomere organization, cardiac excitability, and Ca2+ homeostasis; and validated these markers in the developing mouse cardiac ventricles.
Conclusions: We established an unbiased proteomics method that can provide accurate and specific benchmarking of hPSC-CM maturation, and identified new markers of maturation. Furthermore, this integrated proteomics strategy laid a strong foundation for uncovering molecular basis underlying cardiac development and disease using hPSC-CMs.
Project description:Vascularization and maturation options for cardiac tissue engineered structures are currently intensively investigated. Therefore, the generation and characterisation of all cardiovascular cell types from human pluripotent stem cells (hPSC; either induced -iPSC- or embryonic -hESC) are of particular interest. In our group, differentiation and selection methods were described for obtaining highly pure hPSC-derived cardiomyocytes (CM; selected for αMHC), endothelial cells (EC; selected for CD31) and PDGFRβ expressing cardiac pericyte-like cells (PC). With the purpose of identifying cell type-related mechanisms in co-culture and tissue formation, gene expression profile of hPSC-derived CM, ECs, and PCs was compared to their undifferentiated progeny (hPSC) as well as to primary pericytes (hPC-PL) and fibroblasts (HFF).
Project description:The cell bodies of postganglionic sympathetic neurons innervating the heart primarily reside in the stellate ganglion (SG), alongside neurons innervating other organs and tissues. Whether cardiac-innervating stellate ganglionic neurons (SGNs) exhibit diversity and distinction from those innervating other tissues is not known. To identify and resolve the transcriptomic profiles of SGNs innervating the heart we leveraged retrograde tracing techniques using adeno-associated virus (AAV) expressing fluorescent proteins (GFP or Td-tomato) with single cell RNA sequencing. We investigated electrophysiologic, morphologic, and physiologic roles for subsets of cardiac-specific neurons and found that three of five adrenergic SGN subtypes innervate the heart. These three subtypes stratify into two subpopulations; high (NA1a) and low (NA1b and NA1c) Npy-expressing cells, exhibit distinct morphological, neurochemical, and electrophysiologic characteristics. In physiologic studies in transgenic mouse models modulating NPY signaling, we identified differential control of cardiac responses by these two subpopulations to high and low stress states. These findings provide novel insights into the unique properties of neurons responsible for cardiac sympathetic regulation, with implications for novel strategies to target specific neuronal subtypes for sympathetic blockade in cardiac disease.
Project description:During the postnatal period in mammals, the cardiac muscle transitions from hyperplasic to hypertrophic growth, the extracellular matrix (ECM) undergoes remodeling, and the heart loses regenerative capacity. While ECM maturation and crosstalk between cardiac fibroblasts (CFs) and cardiomyocytes (CM) have been implicated in neonatal heart development, not much is known about specialized fibroblast heterogeneity and functions in the early postnatal period. In order to better understand CF functions in heart maturation and postnatal cardiomyocyte cell cycle arrest, we have performed gene expression profiling and ablation of postnatal CF subpopulations. Fibroblast lineages expressing Tcf21 or Periostin were traced in transgenic GFP reporter mice and their biological functions and transitions during the postnatal period were examined in sorted cells using RNAseq. A subpopulation of highly proliferative Periostin (Postn)+ CFs was found from postnatal day (P)1 to P11 but was not detected at P30. This population was less abundant and transcriptionally different from Tcf21+ resident CFs, which persist in the mature heart. The Postn+ subpopulation preferentially expresses genes related to cell proliferation and neuronal development, while Tcf21+ CFs differentially express genes related to ECM maturation at P7 and immune crosstalk at P30. Ablation of the Postn+ CFs from P0 to P6 led to altered cardiac sympathetic nerve patterning and a reduction in CM binucleation, maturation, and hypertrophic growth. Thus, postnatal CFs are heterogeneous and include a transient proliferative Postn+ subpopulation required for cardiac nerve development and cardiomyocyte maturation soon after birth.
Project description:Human pluripotent stem cell-derived cardiomyocytes (hPSC-CM) are a promising disease model, although hPSC-CMs are not fully mature cardiomyocytes. We examined exponential differentially expressed miRNA/gene to identify critical time-regulated transcripts associated with hPSC-CM differentiation. We uncovered 324 interactions among 29 differentially expressed genes and 51 miRNAs from 20.543 transcripts during the 120 days of hPSC-CM differentiation. We found 16 genes and 26 miRNAs with an inverse pattern of expression (Pearson R-values < -0.5) validated using several human and mouse databases. We further validated these findings using two hPSC-CM lines and seven sampling times over a 30-day protocol and observed 16 inverse interactions among eight genes and 12 miRNAs (Person R-values < -0.5) changing over time. Finally, we tested the top eight miRNAs by adding miRNA mimics to differentiating hPSC-CMs and found that they influenced proliferation and maturation phenotypes. These time-regulated transcripts appear to regulate single or multiple pathways affecting cardiac differentiation.
Project description:Human pluripotent stem cell-derived cardiomyocytes (hPSC-CM) are a promising disease model, although hPSC-CMs are not fully mature cardiomyocytes. We examined exponential differentially expressed miRNA/gene to identify critical time-regulated transcripts associated with hPSC-CM differentiation. We uncovered 324 interactions among 29 differentially expressed genes and 51 miRNAs from 20.543 transcripts during the 120 days of hPSC-CM differentiation. We found 16 genes and 26 miRNAs with an inverse pattern of expression (Pearson R-values < -0.5) validated using several human and mouse databases. We further validated these findings using two hPSC-CM lines and seven sampling times over a 30-day protocol and observed 16 inverse interactions among eight genes and 12 miRNAs (Person R-values < -0.5) changing over time. Finally, we tested the top eight miRNAs by adding miRNA mimics to differentiating hPSC-CMs and found that they influenced proliferation and maturation phenotypes. These time-regulated transcripts appear to regulate single or multiple pathways affecting cardiac differentiation.
Project description:In the heart, cardiomyocytes (CMs) are coupled to capillary endothelial cells (EC), mural cells (e.g. pericytes) and fibroblasts (Fb) promoting structural and electrophysiological tissue maturation as well as vascular network formation. Here, an in vitro model is shown for the investigation of the role of ECs, cardiac pericyte-like cells (PC) and different Fb sources in hPSC-derived bioartificial cardiac tissue (BCT) formation and function. The hPSC-based CMs, ECs, and PCs were differentiated, purified, and characterized for cell-type specific marker expression and function. Differentiated hPSC-PCs were used with hPSC-ECs to generate BCTs and to address their effect on tissue morphology and electromechanical parameters compared to control tissues containing primary dermal or cardiac Fbs.