技术资料

It has been postulated that during human fetal development,all cells of the lung epithelium derive from embryonic,endodermal,NK2 homeobox 1-expressing (NKX2-1+) precursor cells. However,this hypothesis has not been formally tested owing to an inability to purify or track these progenitors for detailed characterization. Here we have engineered and developmentally differentiated NKX2-1GFP reporter pluripotent stem cells (PSCs) in vitro to generate and isolate human primordial lung progenitors that express NKX2-1 but are initially devoid of differentiated lung lineage markers. After sorting to purity,these primordial lung progenitors exhibited lung epithelial maturation. In the absence of mesenchymal coculture support,this NKX2-1+ population was able to generate epithelial-only spheroids in defined 3D cultures. Alternatively,when recombined with fetal mouse lung mesenchyme,the cells recapitulated epithelial-mesenchymal developing lung interactions. We imaged these progenitors in real time and performed time-series global transcriptomic profiling and single-cell RNA sequencing as they moved through the earliest moments of lung lineage specification. The profiles indicated that evolutionarily conserved,stage-dependent gene signatures of early lung development are expressed in primordial human lung progenitors and revealed a CD47hiCD26lo cell surface phenotype that allows their prospective isolation from untargeted,patient-specific PSCs for further in vitro differentiation and future applications in regenerative medicine. View Publication

The epicardium contributes both multi-lineage descendants and paracrine factors to the heart during cardiogenesis and cardiac repair,underscoring its potential for cardiac regenerative medicine. Yet little is known about the cellular and molecular mechanisms that regulate human epicardial development and regeneration. Here,we show that the temporal modulation of canonical Wnt signaling is sufficient for epicardial induction from 6 different human pluripotent stem cell (hPSC) lines,including a WT1-2A-eGFP knock-in reporter line,under chemically-defined,xeno-free conditions. We also show that treatment with transforming growth factor beta (TGF-β)-signalling inhibitors permitted long-term expansion of the hPSC-derived epicardial cells,resulting in a more than 25 population doublings of WT1+ cells in homogenous monolayers. The hPSC-derived epicardial cells were similar to primary epicardial cells both in vitro and in vivo,as determined by morphological and functional assays,including RNA-seq. Our findings have implications for the understanding of self-renewal mechanisms of the epicardium and for epicardial regeneration using cellular or small-molecule therapies. View Publication

Monitoring pluripotent stem cell behaviors (self-renewal and differentiation to specific lineages/phenotypes) is critical for a fundamental understanding of stem cell biology and their translational applications. In this study,a multi-modal stem cell monitoring system was developed to quantitatively characterize physico-electrochemical changes of the cells in real time,in relation to cellular activities during self-renewal or lineage-specific differentiation,in a non-destructive,label-free manner. The system was validated by measuring physical (mass) and electrochemical (impedance) changes in human induced pluripotent stem cells undergoing self-renewal,or subjected to mesendodermal or ectodermal differentiation,and correlating them to morphological (size,shape) and biochemical changes (gene/protein expression). An equivalent circuit model was used to further dissect the electrochemical (resistive and capacitive) contributions of distinctive cellular features. Overall,the combination of the physico-electrochemical measurements and electrical circuit modeling collectively offers a means to longitudinally quantify the states of stem cell self-renewal and differentiation. View Publication

In vitro models of the developing brain such as three-dimensional brain organoids offer an unprecedented opportunity to study aspects of human brain development and disease. However,the cells generated within organoids and the extent to which they recapitulate the regional complexity,cellular diversity and circuit functionality of the brain remain undefined. Here we analyse gene expression in over 80,000 individual cells isolated from 31 human brain organoids. We find that organoids can generate a broad diversity of cells,which are related to endogenous classes,including cells from the cerebral cortex and the retina. Organoids could be developed over extended periods (more than 9 months),allowing for the establishment of relatively mature features,including the formation of dendritic spines and spontaneously active neuronal networks. Finally,neuronal activity within organoids could be controlled using light stimulation of photosensitive cells,which may offer a way to probe the functionality of human neuronal circuits using physiological sensory stimuli. View Publication

During pancreatic development,proliferating pancreatic progenitors activate the proendocrine transcription factor neurogenin 3 (NEUROG3),exit the cell cycle,and differentiate into islet cells. The mechanisms that direct robust NEUROG3 expression within a subset of progenitor cells control the size of the endocrine population. Here we demonstrate that NEUROG3 is phosphorylated within the nucleus on serine 183,which catalyzes its hyperphosphorylation and proteosomal degradation. During progression through the progenitor cell cycle,NEUROG3 phosphorylation is driven by the actions of cyclin-dependent kinases 2 and 4/6 at G1/S cell-cycle checkpoint. Using models of mouse and human pancreas development,we show that lengthening of the G1 phase of the pancreatic progenitor cell cycle is essential for proper induction of NEUROG3 and initiation of endocrine cell differentiation. In sum,these studies demonstrate that progenitor cell-cycle G1 lengthening,through its actions on stabilization of NEUROG3,is an essential variable in normal endocrine cell genesis. View Publication

Rett syndrome (RTT) is an X-linked,neurodevelopmental disorder caused primarily by mutations in the methyl-CpG-binding protein 2 (MECP2) gene,which encodes a multifunctional epigenetic regulator with known links to a wide spectrum of neuropsychiatric disorders. Although postnatal functions of MeCP2 have been thoroughly investigated,its role in prenatal brain development remains poorly understood. Given the well-established importance of microRNAs (miRNAs) in neurogenesis,we employed isogenic human RTT patient-derived induced pluripotent stem cell (iPSC) and MeCP2 short hairpin RNA knockdown approaches to identify novel MeCP2-regulated miRNAs enriched during early human neuronal development. Focusing on the most dysregulated miRNAs,we found miR-199 and miR-214 to be increased during early brain development and to differentially regulate extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase and protein kinase B (PKB/AKT) signaling. In parallel,we characterized the effects on human neurogenesis and neuronal differentiation brought about by MeCP2 deficiency using both monolayer and three-dimensional (cerebral organoid) patient-derived and MeCP2-deficient neuronal culture models. Inhibiting miR-199 or miR-214 expression in iPSC-derived neural progenitors deficient in MeCP2 restored AKT and ERK activation,respectively,and ameliorated the observed alterations in neuronal differentiation. Moreover,overexpression of miR-199 or miR-214 in the wild-type mouse embryonic brains was sufficient to disturb neurogenesis and neuronal migration in a similar manner to Mecp2 knockdown. Taken together,our data support a novel miRNA-mediated pathway downstream of MeCP2 that influences neurogenesis via interactions with central molecular hubs linked to autism spectrum disorders.Molecular Psychiatry advance online publication,25 April 2017; doi:10.1038/mp.2017.86. View Publication

Peripheral blood was collected from a clinically diagnosed 64-year old male multiple schwannoma patient. Peripheral blood mononuclear cells (PBMCs) were reprogrammed with the Yamanaka KMOS reprogramming factors using the Sendai-virus reprogramming system. The transgene-free iPSC line showed pluripotency verified by immunofluorescent staining for pluripotency markers,and the iPSC line was able to differentiate into the 3 germ layers in vivo. The iPSC line also showed normal karyotype. This in vitro cellular model will be useful for further pathological studies of multiple schwannoma. View Publication

Peripheral blood was collected from a clinically diagnosed 79-year old male sporadic Parkinson's disease patient. Peripheral blood mononuclear cells (PBMCs) were reprogrammed with the Yamanaka KMOS reprogramming factors using the Sendai-virus reprogramming system. The transgene-free iPSC line showed pluripotency verified by immunofluorescent staining for pluripotency markers,and the iPSC line was able to differentiate into the 3 germ layers in vivo. The iPSC line also showed normal karyotype. This in vitro cellular model can be used to study the mechanism of sporadic Parkinson's disease and to test new drugs. Resource Table. View Publication

Peripheral blood was collected from a clinically diagnosed 72-year old male patient with later onset Alzheimer's disease. Peripheral blood mononuclear cells (PBMCs) were reprogrammed with the Yamanaka KMOS reprogramming factors using the Sendai-virus reprogramming system. The transgene-free iPSC line showed pluripotency verified by immunofluorescent staining for pluripotency markers,and the iPSC line was able to differentiate into the 3 germ layers in vivo. The iPSC line also showed normal karyotype. This in vitro cellular model will be useful for studying the pathological mechanism of Alzheimer's disease. View Publication

Peripheral blood was collected from a clinically diagnosed 60-year old female patient with multiple schwannoma. Peripheral blood mononuclear cells (PBMCs) were reprogrammed with the Yamanaka KMOS reprogramming factors using the Sendai-virus reprogramming system. The transgene-free iPSC line showed pluripotency verified by immunofluorescent staining for pluripotency markers,and the iPSC line was able to differentiate into the 3 germ layers in vivo. The iPSC line also showed normal karyotype. This in vitro cellular model will be useful for further pathological studies of multiple schwannoma. View Publication

A patient specific point mutation (c.1288GtextgreaterT) of Men1 gene was introduced into wide type iPSC line with CRISPR/Cas9 and single-stranded donor oligonucleotides carrying the mutation. The mutated iPSC line has a heterozygous c.1288GtextgreaterT mutation on exon-9 of Men1 that was confirmed by sequencing analysis. The karyotype of this line was normal and the pluripotency was demonstrated by its ability to differentiate into three germ layers. These artificially created Men1 mutation in wild type iPSC line will help to dissect out the molecular basis of two patients carried the same mutation from one family who were differentially represented hypoglycemia. View Publication

Urine resource cells were collected from a 59-year-old female patient with multiple endocrine neoplasia type 1 syndrome (MEN1) for generating iPS cells with episomal plasmids carrying Oct4,Sox2,Klf4 and miR-302-367. The patient sustained a heterozygous GtextgreaterT transition mutation on the exon 9 of Men1 gene that was confirmed by sequencing analysis on the obtained iPSC lines. Karyotyping indicated the chromosomes with normal appearances and numbers. Their pluripotency was demonstrated by gene expression,as well as their abilities for differentiating into three germ layers. This cell line provides an ideal model for studying MEN1. View Publication