Research Interests: Engineering and Embryo
Research Interests:
The formation and maintenance of the characteristic sharp of neurons mainly relies on the assembly of an organized microtubule ar ray that is the predominant component of the neuronal cytoskeleton During this process there is an evolution... more
The formation and maintenance of the characteristic sharp of neurons mainly relies on the assembly of an organized microtubule ar ray that is the predominant component of the neuronal cytoskeleton During this process there is an evolution in the composition and dynamics of microtubules, resulting in stable microtubule bundles that provide structural support and function in intracellular transport along the neurites. In this essay we provide an overview of structure and funetion relating neuronal microtubules in neurons with particular attention to the roles of multiple tubulin isogenes expression and posttranslational modifications of tubulin.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
ABSTRACT
Research Interests:
Gastrulation of the mouse embryo entails progressive restriction of lineage potency and the organization of the lineage progenitors into a body plan. Here we performed a high-resolution RNA sequencing analysis on single mid-gastrulation... more
Gastrulation of the mouse embryo entails progressive restriction of lineage potency and the organization of the lineage progenitors into a body plan. Here we performed a high-resolution RNA sequencing analysis on single mid-gastrulation mouse embryos to collate a spatial transcriptome that correlated with the regionalization of cell fates in the embryo. 3D rendition of the quantitative data enabled the visualization of the spatial pattern of all expressing genes in the epiblast in a digital whole-mount in situ format. The dataset also identified genes that (1) are co-expressed in a specific cell population, (2) display similar global pattern of expression, (3) have lineage markers, (4) mark domains of transcriptional and signaling activity associated with cell fates, and (5) can be used as zip codes for mapping the position of single cells isolated from the mid-gastrula stage embryo and the embryo-derived stem cells to the equivalent epiblast cells for delineating their prospective cell fates.
Research Interests: Biology, Cell Biology, Transcription Factors, Medicine, In Situ Hybridization, and 15 moreAnnotation, Signal Transduction, Embryo, Transcriptome, Biological Sciences, Cell Differentiation, Pregnancy, Mice, Female, Animals, Gastrulation, Gene ontology, Embryonic Stem Cells, Gene Regulatory Networks, and Medical and Health Sciences
Research Interests:
In vertebrates, hematopoiesis occurring in different niches is orchestrated by intrinsic and extrinsic regulators. Previous studies have revealed numerous linear and planar regulatory mechanisms. However, a multi-dimensional... more
In vertebrates, hematopoiesis occurring in different niches is orchestrated by intrinsic and extrinsic regulators. Previous studies have revealed numerous linear and planar regulatory mechanisms. However, a multi-dimensional transcriptomic atlas of any given hematopoietic organ has not yet been established. Here, we use multiple RNA sequencing (RNA-seq) approaches, including cell type-specific, temporal bulk RNA-seq, in vivo GEO-seq, and single-cell RNA-seq (scRNA-seq), to characterize the detailed spatiotemporal transcriptome during hematopoietic stem and progenitor cell (HSPC) expansion in the caudal hematopoietic tissue (CHT) of zebrafish. Combinatorial expression profiling reveals that, in the CHT niche, HSPCs and their neighboring supporting cells are co-regulated by shared signaling pathways and intrinsic factors, such as integrin signaling and Smchd1. Moreover, scRNA-seq analysis unveils the strong association between cell cycle status and HSPC differentiation. Taken together, we report a global transcriptome landscape that provides valuable insights and a rich resource to understand HSPC expansion in an intact vertebrate hematopoietic organ.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Stem Cells, Biology, Cell Biology, Medicine, Multidisciplinary, and 15 moreBone Morphogenetic Proteins, Signal Transduction, Cell Differentiation, Mice, Animals, Phosphorylation, Epidermal Growth Factor, Embryonic Development, Retinoic Acid, Tretinoin, Neural Tube Defects, Cell Proliferation, Cell Cycle Proteins, Glycogen Synthase Kinase, and Chick embryo
Differentiation into diverse cell lineages requires orchestration of gene regulatory networks guiding cell fate choices. Here, we present the dissection of cellular composition and gene networks from transcriptomic data of 43,168 cells... more
Differentiation into diverse cell lineages requires orchestration of gene regulatory networks guiding cell fate choices. Here, we present the dissection of cellular composition and gene networks from transcriptomic data of 43,168 cells across five discrete time points during cardiac-directed differentiation. We utilize unsupervised clustering and implement a lineage trajectory prediction algorithm that integrates transcription factor networks to predict cell fate progression of 15 subpopulations that correlate with germ layer and cardiovascular differentiation in vivo. These data reveal transcriptional networks underlying lineage derivation of mesoderm, definitive endoderm, vascular endothelium, cardiac precursors, and definitive cell types that comprise cardiomyocytes and a previously unrecognized cardiac outflow tract population. Single cell analysis of genetic regulators governing cardiac fate diversification identified the non-DNA binding homeodomain protein, HOPX, as functionally necessary for endothelial specification. Our findings further implicate dysregulation of HOPX during in vitro cardiac-directed differentiation underlying the molecular and physiological immaturity of stem cell-derived cardiomyocytes.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
SummaryDuring mammalian embryogenesis, spatial regulation of gene expression and cell signaling are functionally coupled with lineage specification, patterning of tissue progenitors and germ layer morphogenesis. While the mouse model has... more
SummaryDuring mammalian embryogenesis, spatial regulation of gene expression and cell signaling are functionally coupled with lineage specification, patterning of tissue progenitors and germ layer morphogenesis. While the mouse model has been instrumental for our understanding of mammalian development, comparatively little is known about human and non-human primate gastrulation due to the restriction of both technical and ethical issues. Here, we present a morphological and molecular survey of spatiotemporal dynamics of cell types populating the non-human primate embryos during gastrulation. We performed serial sections of Cynomolgus monkeys (Macaca fascicularis) gastrulating embryos at 1-day temporal resolution from E17 to E21, and reconstructed three-dimensional digital models based on high-resolution anatomical atlas that revealed the dynamic changes in the geography of the mesoderm and primitive streaks. Spatial transcriptomics identified unique gene profiles that correspond to ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
During embryonic development, tissue-specific transcription factors and chromatin remodelers function together to ensure gradual, coordinated differentiation of multiple lineages. Here, we define this regulatory interplay in the... more
During embryonic development, tissue-specific transcription factors and chromatin remodelers function together to ensure gradual, coordinated differentiation of multiple lineages. Here, we define this regulatory interplay in the developing retinal pigmented epithelium (RPE), a neuroectodermal lineage essential for the development, function and maintenance of the adjacent retina. We present a high-resolution spatial transcriptomic atlas of the developing mouse RPE and the adjacent ocular mesenchyme obtained by geographical position sequencing (Geo-seq) of a single developmental stage of the eye that encompasses young and more mature ocular progenitors. These transcriptomic data, available online, reveal the key transcription factors and their gene regulatory networks during RPE and ocular mesenchyme differentiation. Moreover, conditional inactivation followed by Geo-seq revealed that this differentiation program is dependent on the activity of SWI/SNF complexes, shown here to control...
Research Interests:
Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder associated with aging. Due to its insidious onset, protracted progression, and unclear pathogenesis, it is considered one of the most obscure and intractable... more
Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder associated with aging. Due to its insidious onset, protracted progression, and unclear pathogenesis, it is considered one of the most obscure and intractable brain disorders, and currently, there are no effective therapies for it. Convincing evidence indicates that the irreversible decline of cognitive abilities in patients coincides with the deterioration and degeneration of neurons and synapses in the AD brain. Human neural stem cells (NSCs) hold the potential to functionally replace lost neurons, reinforce impaired synaptic networks, and repair the damaged AD brain. They have therefore received extensive attention as a possible source of donor cells for cellular replacement therapies for AD. Here, we review the progress in NSC-based transplantation studies in animal models of AD and assess the therapeutic advantages and challenges of human NSCs as donor cells. We then formulate a promising transplantation...
Research Interests:
SUMMARYSpinal motor neurons deficiency results in a series of devastating disorders such as amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA) and spinal cord injury (SCI). These disorders are currently incurable, while... more
SUMMARYSpinal motor neurons deficiency results in a series of devastating disorders such as amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA) and spinal cord injury (SCI). These disorders are currently incurable, while human pluripotent stem cells (hPSCs)-derived spinal motor neurons are promising but suffered from low-efficiency, functional immaturity and lacks of posterior cellular identity. In this study, we have established human spinal cord neural progenitor cells (hSCNPCs) via hPSCs differentiated neuromesodermal progenitors (NMPs) and demonstrated the hSCNPCs can be continuously expanded up to 40 passages. hSCNPCs can be rapidly differentiated into posterior spinal motor neurons with high efficiency. The functional maturity has been examined in detail. Moreover, a co-culture scheme which is compatible for both neural and muscular differentiation is developed to mimic the neuromuscular junction (NMJ) formation in vitro. Together, these studies highlight the po...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Human induced neural stem/progenitor cells (iNPCs) are a promising source of cells for stem cell-based therapy. The therapeutic potential of human iNPCs has been extensively tested in animal models, including both mouse and monkey models.... more
Human induced neural stem/progenitor cells (iNPCs) are a promising source of cells for stem cell-based therapy. The therapeutic potential of human iNPCs has been extensively tested in animal models, including both mouse and monkey models. However, the comprehensive characterization of grafted iNPCs in the brain of non-human primates has been lagged behind. In this study, we transplanted human iNPCs into the basal forebrain of adult cynomolgus monkeys. We found that grafted iNPCs predominantly differentiated into neurons that displayed long-term survival up to 12 months. Additionally, iNPC-derived human neurons gradually matured in term of morphology and subtype differentiation. More excitingly, we observed that human neurons displayed electrophysiological activities resembling those of mature neurons, indicating the acquisition of functional membrane properties. Collectively, this study systematically characterized human iNPCs in the brain of non-human primates, and will provide inv...
Research Interests:
Vascular establishment is one of the early events in embryogenesis. It is believed that vessel-initiating endothelial progenitors cluster to form the first primitive vessel. Understanding the molecular identity of these progenitors is... more
Vascular establishment is one of the early events in embryogenesis. It is believed that vessel-initiating endothelial progenitors cluster to form the first primitive vessel. Understanding the molecular identity of these progenitors is crucial in order to elucidate lineage hierarchy. In this study, we identify protein C receptor (Procr) as an endothelial progenitor marker and investigate the role of Procr+ progenitors during embryonic vascular development. Using a ProcrmGFP-2A-lacZ reporter, we reveal a much earlier Procr expression (embryonic day 7.5) than previously acknowledged (embryonic day 13.5). Genetic fate-mapping experiments using ProcrCre and ProcrCreER demonstrate that Procr+ cells give rise to blood vessels throughout the entire embryo proper. Single-cell RNA-sequencing analyses place Procr+ cells at the start of endothelial commitment and maturation. Furthermore, targeted ablation of Procr+ cells results in failure of vessel formation and early embryonic lethality. Nota...
Research Interests:
Summary Generating induced neural stem/progenitor cells (iNPCs) from somatic cells for medical applications has remained challenging. Here, we describe a reliable protocol to make human iNPCs from a small volume of immobilized adult... more
Summary Generating induced neural stem/progenitor cells (iNPCs) from somatic cells for medical applications has remained challenging. Here, we describe a reliable protocol to make human iNPCs from a small volume of immobilized adult peripheral blood by direct reprogramming. We have verified that the integration-free human iNPCs can efficiently differentiate into mature neurons in mouse brain upon transplantation and display capacities to functionally replace the damaged neurons, suggesting their potential as donor cells in developing replacement medicine for neurodegenerative diseases. For complete details on the use and execution of this protocol, please refer to Zhang et al. (2019).
Research Interests:
Research Interests:
The combination use of TGF-β, M-CSF, and IL-6 represents a promising therapy to repair traumatic brain injury.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Biology, Cell Biology, Epigenetics, Medicine, Embryo, and 3 moreMethylation, Histone, and substitution (logic)
Establishment of progenitor cell populations and lineage diversity during embryogenesis and the differentiation of pluripotent stem cells is a fascinating and intricate biological process. Conceptually, an understanding of this... more
Establishment of progenitor cell populations and lineage diversity during embryogenesis and the differentiation of pluripotent stem cells is a fascinating and intricate biological process. Conceptually, an understanding of this developmental process provides a framework to integrate stem-cell pluripotency, cell competence and differentiating potential with the activity of extrinsic and intrinsic molecular determinants. The recent advent of enabling technologies of high-resolution transcriptome analysis at the cellular, population and spatial levels proffers the capability of gaining deeper insights into the attributes of the gene regulatory network and molecular signaling in lineage specification and differentiation. In this review, we provide a snapshot of the emerging enabling genomic technologies that contribute to the study of development and stem-cell biology.
Research Interests:
The ectoderm has the capability to generate epidermis and neuroectoderm and plays imperative roles during the early embryonic development. Our recent study uncovered a region with ectodermal progenitor potential in mouse embryo at... more
The ectoderm has the capability to generate epidermis and neuroectoderm and plays imperative roles during the early embryonic development. Our recent study uncovered a region with ectodermal progenitor potential in mouse embryo at embryonic day 7.0 and revealed that Nodal inhibition is essential for its formation. Here, we demonstrate that through brief inhibition of Nodal signaling in vitro, mouse embryonic stem cell (ESC)-derived epiblast stem cells (ESD-EpiSCs) could be committed to transient ectodermal progenitor populations, which possess the ability to give rise to neural or epidermal ectoderm in the absence or presence of BMP4, respectively. Mechanistic studies reveal that BMP4 recruits distinct transcriptional targets in ESD-EpiSCs and ectoderm-like cells. Furthermore, FGF-Erk signaling may also be alleviated during the generation of ectoderm-like cells. Thus, our data suggest that instructive interactions among several extracellular signals participate in the commitment of ...
Research Interests:
To understand the biological activities of the nerve regeneration conditioned fluid (NRCF). Nerve regeneration chamber was made by using silicone tube bridging distal and proximal ends of severed SD rat's sciatic nerve. The biological... more
To understand the biological activities of the nerve regeneration conditioned fluid (NRCF). Nerve regeneration chamber was made by using silicone tube bridging distal and proximal ends of severed SD rat's sciatic nerve. The biological activities of the proteins in NRCF, which were separated by natural polyacrylamide gel electrophoresis (PAGE), were analysed by being cocultured with excised neonatal dorsal root ganglia (DRG). Eight separated protein bands of NRCF were observed between 67-669 ku in molecular weight, and the protein bands between 232-440 ku showed strong neurotrophic and chemotactic function. NRCF has the promoting effects on nerve regeneration.
Research Interests:
To study the localization of CTP: phosphocholine cytidylyltransferase beta isoform (CCTbeta) in rat brain, its expression in insect cells and enzymatic properties. Using digoxigenin-labeled CCTbeta probes, in situ hybridization was... more
To study the localization of CTP: phosphocholine cytidylyltransferase beta isoform (CCTbeta) in rat brain, its expression in insect cells and enzymatic properties. Using digoxigenin-labeled CCTbeta probes, in situ hybridization was carried out in rat brain wax sections. CCTbeta was overexpressed in Trichoplusia Ni (Tn) cells using baculovirus expression system. CTP:phosphocholine cytidylyltransferase assay (CT assay) and [3H] metabolic labeling experiment were used to study its activity, properties, and the effect on phosphatidylcholine (PC) synthesis. (1) CCbeta was abundant in CA1, CA2, CA4, and dentate gyrus (DG) region of hippocampus. (2) The content of CCTbeta in transfected Tn cells was over 1 104 times of that in rat brain, and CCTbeta increased the PC synthesis of Tn cells. (3) Hexadecylphosphocholine as well as some ions like Zn2+ and PO3-4 could inhibit the activity of CCTbeta, dCTP was another adaptive substrate of CCTbeta besides CTP. CCTbeta showed a similar localizatio...