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  • Rasmussen Glerup posted an update 3 weeks, 4 days ago

    We aimed to establish an in vitro differentiation procedure to generate matured small intestinal cells mimicking human small intestine from human-induced pluripotent stem cells (iPSCs). We previously reported the efficient generation of CDX2-expressing intestinal progenitor cells from embryonic stem cells (ESCs) using 6-bromoindirubin-3′-oxime (BIO) and (3,5-difluorophenylacetyl)-L-alanyl-L-2-phenylglycine tert-butyl ester (DAPT) to treat definitive endodermal cells. Here, we demonstrate the generation of enterocyte-like cells by culturing human iPSC-derived intestinal progenitor cells on a collagen vitrigel membrane (CVM) and treating cells with a simple maturation medium containing BIO, DMSO, dexamethasone, and activated vitamin D3. Functional tests further confirmed that these iPSC-derived enterocyte-like cells exhibit P-gp- and BCRP-mediated efflux and cytochrome P450 3A4 (CYP3A4)-mediated metabolism. We concluded that hiPS cell-derived enterocyte-like cells can be used as a model for the evaluation of drug transport and metabolism studies in the human small intestine.Organoids (ORGs) are increasingly used as models of cerebral cortical development. Here, we compared transcriptome and cellular phenotypes between telencephalic ORGs and monolayers (MONs) generated in parallel from three biologically distinct induced pluripotent stem cell (iPSC) lines. Multiple readouts revealed increased proliferation in MONs, which was caused by increased integrin signaling. MONs also exhibited altered radial glia (RG) polarity and suppression of Notch signaling, as well as impaired generation of intermediate progenitors, outer RG, and cortical neurons, which were all partially reversed by reaggregation of dissociated cells. Network analyses revealed co-clustering of cell adhesion, Notch-related transcripts and their transcriptional regulators in a module strongly downregulated in MONs. The data suggest that ORGs, with respect to MONs, initiate more efficient Notch signaling in ventricular RG owing to preserved cell adhesion, resulting in subsequent generation of intermediate progenitors and outer RG, in a sequence that recapitulates the cortical ontogenetic process.Mutations in the photoreceptor transcription factor gene cone-rod homeobox (CRX) lead to distinct retinopathy phenotypes, including early-onset vision impairment in dominant Leber congenital amaurosis (LCA). Using induced pluripotent stem cells (iPSCs) from a patient with CRX-I138fs48 mutation, we established an in vitro model of CRX-LCA in retinal organoids that showed defective photoreceptor maturation by histology and gene profiling, with diminished expression of visual opsins. learn more Adeno-associated virus (AAV)-mediated CRX gene augmentation therapy partially restored photoreceptor phenotype and expression of phototransduction-related genes as determined by single-cell RNA-sequencing. Retinal organoids derived from iPSCs of a second dominant CRX-LCA patient carrying K88N mutation revealed the loss of opsin expression as a common phenotype, which was alleviated by AAV-mediated augmentation of CRX. Our studies provide a proof-of-concept for developing gene therapy of dominant CRX-LCA and other CRX retinopathies.Severe congenital neutropenia (SCN) is a life-threatening disorder most often caused by dominant mutations of ELANE that interfere with neutrophil maturation. We conducted a pooled CRISPR screen in human hematopoietic stem and progenitor cells (HSPCs) that correlated ELANE mutations with neutrophil maturation potential. Highly efficient gene editing of early exons elicited nonsense-mediated decay (NMD), overcame neutrophil maturation arrest in HSPCs from ELANE-mutant SCN patients, and produced normal hematopoietic engraftment function. Conversely, terminal exon frameshift alleles that mimic SCN-associated mutations escaped NMD, recapitulated neutrophil maturation arrest, and established an animal model of ELANE-mutant SCN. Surprisingly, only -1 frame insertions or deletions (indels) impeded neutrophil maturation, whereas -2 frame late exon indels repressed translation and supported neutrophil maturation. Gene editing of primary HSPCs allowed faithful identification of variant pathogenicity to clarify molecular mechanisms of disease and encourage a universal therapeutic approach to ELANE-mutant neutropenia, returning normal neutrophil production and preserving HSPC function.Despite of its high morbidity and mortality, there is still a lack of effective treatment for ischemic stroke in part due to our incomplete understanding of molecular mechanisms of its pathogenesis. In this study, we demonstrate that SHH-PTCH1-GLI1-mediated axonal guidance signaling and its related neurogenesis, a central pathway for neuronal development, also plays a critical role in early stage of an acute stroke model. Specifically, in vivo, we evaluated the effect of GXNI on ischemic stroke mice via using the middle cerebral artery embolization model, and found that GXNI significantly alleviated cerebral ischemic reperfusion (I/R) injury by reducing the volume of cerebral infarction, neurological deficit score and cerebral edema, reversing the BBB permeability and histopathological changes. A combined approach of RNA-seq and network pharmacology analysis was used to reveal the underlying mechanisms of GXNI followed by RT-PCR, immunohistochemistry and western blotting validation. It was pointed out that axon guidance signaling pathway played the most prominent role in GXNI action with Shh, Ptch1, and Gli1 genes as the critical contributors in brain protection. In addition, GXNI markedly prevented primary cortical neuron cells from oxygen-glucose deprivation/reoxygenation damage in vitro, and promoted axon growth and synaptogenesis of damaged neurons, which further confirmed the results of in vivo experiments. Moreover, due to the inhibition of the SHH-PTCH1-GLI1 signaling pathway by cyclopropylamine, the effect of GXNI was significantly weakened. Hence, our study provides a novel option for the clinical treatment of acute ischemic stroke by GXNI via SHH-PTCH1-GLI1-mediated axonal guidance signaling, a neuronal development pathway previously considered for after-stroke recovery.

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