技术资料

Creation of disease models utilizing hiPSCs in combination with CRISPR/Cas9 gene editing enable mechanistic insights into differential pharmacological responses. This allows translation of efficacy and safety findings from a healthy to a diseased state and provides a means to predict clinical outcome sooner during drug discovery. Calcium handling disturbances including reduced expression levels of the type 2 ryanodine receptor (RYR2) are linked to cardiac dysfunction; here we have created a RYR2 deficient human cardiomyocyte model that mimics some aspects of heart failure. RYR2 deficient cardiomyocytes show differential pharmacological responses to L-type channel calcium inhibitors. Phenotypic and proteomic characterization reveal novel molecular insights with altered expression of structural proteins including CSRP3,SLMAP,and metabolic changes including upregulation of the pentose phosphate pathway and increased sensitivity to redox alterations. This genetically engineered in vitro cardiovascular model of RYR2 deficiency supports the study of pharmacological responses in the context of calcium handling and metabolic dysfunction enabling translation of drug responses from healthy to perturbed cellular states. View Publication

Development requires coordinated interactions between the epiblast,which generates the embryo proper; the trophectoderm,which generates the placenta; and the hypoblast,which forms both the anterior signalling centre and the yolk sac. These interactions remain poorly understood in human embryogenesis because mechanistic studies have only recently become possible. Here we examine signalling interactions post-implantation using human embryos and stem cell models of the epiblast and hypoblast. We find anterior hypoblast specification is NODAL dependent,as in the mouse. However,while BMP inhibits anterior signalling centre specification in the mouse,it is essential for its maintenance in human. We also find contrasting requirements for BMP in the naive pre-implantation epiblast of mouse and human embryos. Finally,we show that NOTCH signalling is important for human epiblast survival. Our findings of conserved and species-specific factors that drive these early stages of embryonic development highlight the strengths of comparative species studies. Weatherbee,Weberling,Gantner et al. find contrasting requirements for BMP in the anterior signalling centre and pre-implantation epiblast between mice and humans. They further find that NOTCH may be indispensable for human epiblast survival. View Publication

BackgroundThree common isoforms of the apolipoprotein E (APOE) gene - APOE2,APOE3,and APOE4 - hold varying significance in Alzheimer’s Disease (AD) risk. The APOE4 allele is the strongest known genetic risk factor for late-onset Alzheimer’s Disease (AD),and its expression has been shown to correlate with increased central nervous system (CNS) amyloid deposition and accelerated neurodegeneration. Conversely,APOE2 is associated with reduced AD risk and lower CNS amyloid burden. Recent clinical data have suggested that increased blood-brain barrier (BBB) leakage is commonly observed among AD patients and APOE4 carriers. However,it remains unclear how different APOE isoforms may impact AD-related pathologies at the BBB.MethodsTo explore potential impacts of APOE genotypes on BBB properties and BBB interactions with amyloid beta,we differentiated isogenic human induced pluripotent stem cell (iPSC) lines with different APOE genotypes into both brain microvascular endothelial cell-like cells (BMEC-like cells) and brain pericyte-like cells. We then compared the effect of different APOE isoforms on BBB-related and AD-related phenotypes. Statistical significance was determined via ANOVA with Tukey’s post hoc testing as appropriate.ResultsIsogenic BMEC-like cells with different APOE genotypes had similar trans-endothelial electrical resistance,tight junction integrity and efflux transporter gene expression. However,recombinant APOE4 protein significantly impeded the “brain-to-blood” amyloid beta 1–40 (A?40) transport capabilities of BMEC-like cells,suggesting a role in diminished amyloid clearance. Conversely,APOE2 increased amyloid beta 1–42 (A?42) transport in the model. Furthermore,we demonstrated that APOE-mediated amyloid transport by BMEC-like cells is dependent on LRP1 and p-glycoprotein pathways,mirroring in vivo findings. Pericyte-like cells exhibited similar APOE secretion levels across genotypes,yet APOE4 pericyte-like cells showed heightened extracellular amyloid deposition,while APOE2 pericyte-like cells displayed the least amyloid deposition,an observation in line with vascular pathologies in AD patients.ConclusionsWhile APOE genotype did not directly impact general BMEC or pericyte properties,APOE4 exacerbated amyloid clearance and deposition at the model BBB. Conversely,APOE2 demonstrated a potentially protective role by increasing amyloid transport and decreasing deposition. Our findings highlight that iPSC-derived BBB models can potentially capture amyloid pathologies at the BBB,motivating further development of such in vitro models in AD modeling and drug development.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12987-024-00580-2. View Publication

Malaria caused by Plasmodium falciparum infection results in severe complications including cerebral malaria (CM),in which approximately 30% of patients end up with neurological sequelae. Sparse in vitro cell culture-based experimental models which recapitulate the molecular basis of CM in humans has impeded progress in our understanding of its etiology. This study employed healthy human induced pluripotent stem cells (iPSCs)-derived neuronal cultures stimulated with hemozoin (HMZ) - the malarial toxin as a model for CM. Secretome,qRT-PCR,Metascape,and KEGG pathway analyses were conducted to assess elevated proteins,genes,and pathways. Neuronal cultures treated with HMZ showed enhanced secretion of interferon-gamma (IFN-?),interleukin (IL)1-beta (IL-1?),IL-8 and IL-16. Enrichment analysis revealed malaria,positive regulation of cytokine production and positive regulation of mitogen-activated protein kinase (MAPK) cascade which confirm inflammatory response to HMZ exposure. KEGG assessment revealed up-regulation of malaria,MAPK and neurodegenerative diseases-associated pathways which corroborates findings from previous studies. Additionally,HMZ induced DNA damage in neurons. This study has unveiled that exposure of neuronal cultures to HMZ,activates molecules and pathways similar to those observed in CM and neurodegenerative diseases. Furthermore,our model is an alternative to rodent experimental models of CM. View Publication

Fabry disease (FD) is a lysosomal storage disorder in which ?-galactosidase (GLA) deficiency leads to a build-up of globo-triaosylceramide (Gb3) in various cell types. Gb3 accumulation leads to the abnormalities of microvascular function associated with FD. Previously,we discovered significant abnormalities in vascular endothelial cells (VECs) derived from FD-induced pluripotent stem cells. We then used a cell-based system to screen a group of clinical compounds for candidates capable of rescuing those abnormalities. Lomerizine was one of the most promising candidates because it alleviated a variety of FD-associated phenotypes both in vitro and in vivo. Lomerizine reduced mitochondria Ca2+?levels,ROS generation,and the maximal respiration of FD-VECs in vitro. This led to a suppression of the endothelial-to-mesenchymal transition (EndMT) and rescued FD-VEC function. Furthermore,FD-model mice (Gla?/?/TSP1Tg) treated orally with lomerizine for 6 months showed clear improvement of several FD phenotypes,including left ventricular hypertrophy,renal fibrosis,anhidrosis,and heat intolerance. Thus,our results suggest lomerizine as a novel candidate for FD therapy. View Publication

Biallelic mutations in the DCPS gene disrupting the decapping activity of the scavenger decapping protein DcpS,leads to neurodevelopmental deficiencies and intellectual disability. However,the molecular basis for the neurogenesis defects in these individuals remains unknown. Here we show that cells derived from individuals with a DCPS mutation harbor a creatine deficiency and a corresponding elevation of the creatine precursor,guanidinoacetate (GAA). The altered metabolite levels are a consequence of a reduction in both the mRNA and protein levels for the enzyme that converts GAA into creatine,guanidinoacetate methyltransferase. Importantly,the compromised neurogenesis and neurite outgrowth phenotypes observed during the differentiation of DcpS mutant patient derived induced pluripotent stem cells into neurons was reversed upon supplementation of creatine monohydrate. These findings suggest creatine deficiency as an underlying factor for the neurogenetic defect detected in DcpS mutant cells and a potential driver of the neurological deficiencies in affected individuals. View Publication

The 22q11.2 deletion syndrome (22qDS) is a human disorder where the majority of clinical manifestations originate during embryonic development. 22qDS is caused by a microdeletion in one chromosome 22,including DGCR8,an essential gene for microRNA (miRNA) production. However,the impact of DGCR8 hemizygosity on human development is still unclear. In this study,we generated two human pluripotent cell models containing a single functional DGCR8 allele to elucidate its role in early development. DGCR8+/? human embryonic stem cells (hESCs) showed increased apoptosis as well as self-renewal and differentiation defects in both the naïve and primed states. The expression of primate-specific miRNAs was largely affected,due to impaired miRNA processing and chromatin accessibility. DGCR8+/? hESCs also displayed a pronounced reduction in human endogenous retrovirus class H (HERVH) expression,a primate-specific retroelement essential for pluripotency maintenance. The reintroduction of miRNAs belonging to the primate-specific C19MC cluster as well as the miR-371-3 cluster rescued the defects of DGCR8+/? cells. Mechanistically,downregulation of HERVH by depletion of primate-specific miRNAs was mediated by KLF4. Altogether,we show that DGCR8 is haploinsufficient in humans and that miRNAs and transposable elements may have co-evolved in primates as part of an essential regulatory network to maintain stem cell identity. View Publication

THOC6 variants are the genetic basis of autosomal recessive THOC6 Intellectual Disability Syndrome (TIDS). THOC6 is critical for mammalian Transcription Export complex (TREX) tetramer formation,which is composed of four six-subunit THO monomers. The TREX tetramer facilitates mammalian RNA processing,in addition to the nuclear mRNA export functions of the TREX dimer conserved through yeast. Human and mouse TIDS model systems revealed novel THOC6-dependent,species-specific TREX tetramer functions. Germline biallelic Thoc6 loss-of-function (LOF) variants result in mouse embryonic lethality. Biallelic THOC6 LOF variants reduce the binding affinity of ALYREF to THOC5 without affecting the protein expression of TREX members,implicating impaired TREX tetramer formation. Defects in RNA nuclear export functions were not detected in biallelic THOC6 LOF human neural cells. Instead,mis-splicing was detected in human and mouse neural tissue,revealing novel THOC6-mediated TREX coordination of mRNA processing. We demonstrate that THOC6 is required for key signaling pathways known to regulate the transition from proliferative to neurogenic divisions during human corticogenesis. Together,these findings implicate altered RNA processing in the developmental biology of TIDS neuropathology. THOC6 is required for TREX tetramer formation. Analysis of pathogenic THOC6 variants differentiate the conserved mRNA export functions of TREX dimers and RNA processing functions of TREX tetramers underlying THOC6 Intellectual Disability Syndrome. View Publication

A limited number of accessible and representative models of human trophoblast cells currently exist for the study of placentation. Current stem cell models involve either a transition through a naïve stem cell state or precise dynamic control of multiple growth factors and small-molecule cues. Here,we demonstrated that a simple five-day treatment of human induced pluripotent stem cells with two small molecules,retinoic acid (RA) and Wnt agonist CHIR 99021 (CHIR),resulted in rapid,synergistic upregulation of CDX2. Transcriptomic analysis of RA + CHIR-treated cells showed high similarity to primary trophectoderm cells. Multipotency was verified via further differentiation towards cells with syncytiotrophoblast or extravillous trophoblast features. RA + CHIR-treated cells were also assessed for the established criteria defining a trophoblast cell model,and they possess all the features necessary to be considered valid. Collectively,our data demonstrate a facile,scalable method for generating functional trophoblast-like cells in vitro to better understand the placenta. View Publication

BackgroundPaired box 1 (PAX1) is a transcription factor and essential for the development of pharyngeal pouches-derived tissues,including thymus. PAX1 mutations are identified in Severe Combined Immunodeficiency (SCID) patients with Otofaciocervical Syndrome Type 2 (OTFCS2). However,despite the critical roles of PAX1 in embryonic development and diseases,detailed insights into its molecular mode of action are critically missing.MethodsThe repressing roles of PAX1 and SCID associated mutants on Wnt signaling pathway were investigated by luciferase reporter assays,qRT-PCR and in situ hybridization in HEK293FT,HCT116 cells and zebrafish embryos,respectively. Co-immunoprecipitation (co-IP) and western blotting assays were carried out to identify the molecular mechanisms underlying PAX1’s role on Wnt signaling pathway. hESC based endoderm differentiation,flow cytometry,high-throughput sequencing data analysis,and qRT-PCR assays were utilized to determine the roles of PAX1 during endoderm differentiation.ResultsHere,we show that PAX1 represses canonical Wnt signaling pathway in vertebrate cells. Mechanically,PAX1 competes with SUMO E3 ligase PIASy to bind to TCF7L2,thus perturbing TCF7L2 SUMOylation level,further reducing its transcriptional activity and protein stability. Moreover,we reveal that PAX1 plays dual roles in hESC-derived definitive and foregut/pharyngeal endoderm cells,which give rise to the thymus epithelium,by inhibiting Wnt signaling. Importantly,our data show PAX1 mutations found in SCID patients significantly compromise the suppressing ability of PAX1 on Wnt signaling.ConclusionsOur study presents a novel molecular mode of action of PAX1 in regulation of canonical Wnt signaling and endoderm differentiation,thus providing insights for the molecular basis of PAX1 associated SCID,offering better understanding of the behavior of PAX1 in embryogenesis.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12964-024-01629-3. View Publication

Background: Takotsubo cardiomyopathy (TTC) is marked by an acute,transient,and reversible left ventricular systolic dysfunction triggered by stress,with endothelial dysfunction being one of its pathophysiological mechanisms. However,the precise molecular mechanism underlying the interaction between endothelial cells and cardiomyocytes during TTC remains unclear. This study reveals that exosomal miRNAs derived from endothelial cells exposed to catecholamine contribute to ion channel dysfunction in the setting of TTC. Methods: Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were treated with epinephrine (Epi) or exosomes (Exo) from Epi-treated human cardiac microvascular endothelial cells (HCMECs) or Exo derived from HCMECs transfected with miR-126-3p. The immunofluorescence staining,flow cytometry,qPCR,single-cell contraction,intracellular calcium transients,patch-clamp,dual luciferase reporter assay and western blot were performed for the study. Results: Modeling TTC with high doses of epinephrine (Epi) treatment in hiPSC-CMs shows suppression of depolarization velocity (Vmax),prolongation of action potential duration (APD),and induction of arrhythmic events. Exo derived from HCMECs treated with Epi (Epi-exo) mimicked or enhanced the effects of Epi. Epi exposure led to elevated levels of miR-126-3p in both HCMECs and their exosomes. Exo enriched with miR-126-3p demonstrated similar effects as Epi-exo,establishing the crucial role of miR-126-3p in the mechanism of Epi-exo. Dual luciferase reporter assay coupled with gene mutation techniques identified that miR-126-3p was found to target the regulator of G-protein signaling 3 (RGS3) gene. Western blot and qPCR analyses confirmed that miR-126-3p-mimic reduced RGS3 expression in both HCMECs and hiPSC-CMs,indicating miR-126-3p inhibits RGS3 signaling. Additionally,miR-126-3p levels were significantly higher in the serum of TTC patients compared to healthy controls and patients who had recovered from TTC. Conclusions: Our study is the first to reveal that exosomal miR-126-3p,originating from endothelial cells,contributes to ion channel dysfunction by regulating RGS3 signaling in cardiomyocytes. These findings provide new perspectives on the pathogenesis of TTC and suggest potential therapeutic targets for treatment. View Publication

Current approaches to the treatment of schizophrenia have mainly focused on the protein-coding part of the genome; in this context,the roles of microRNAs have received less attention. In the present study,we analyze the microRNAome in the blood and postmortem brains of schizophrenia patients,showing that the expression of miR-99b-5p is downregulated in both the prefrontal cortex and blood of patients. Lowering the amount of miR-99b-5p in mice leads to both schizophrenia-like phenotypes and inflammatory processes that are linked to synaptic pruning in microglia. The microglial miR-99b-5p-supressed inflammatory response requires Z-DNA binding protein 1 (Zbp1),which we identify as a novel miR-99b-5p target. Antisense oligonucleotides against Zbp1 ameliorate the pathological effects of miR-99b-5p inhibition. Our findings indicate that a novel miR-99b-5p-Zbp1 pathway in microglia might contribute to the pathogenesis of schizophrenia. Synopsis The involvement of microRNAs in the pathogenesis of schizophrenia is not well-understood. This study shows that miR-99b-5p regulates Z-DNA binding protein 1 (Zbp1) to control inflammatory responses in microglia and the development of schizophrenia-like symptoms in mice. miR-99b-5p is downregulated in the blood and brains of schizophrenia patients.miR-99b-5p inhibition induces schizophrenia-like phenotypes in mice and microglial inflammation.Zbp1 is a novel miR-99b-5p target in microglia.Zbp1 antisense oligos ameliorate the pathological outcomes of decreased miR-99b-5p levels. Dysregulation of a novel miR-99b-5p-Zbp1 (Z-DNA binding protein 1) pathway in microglia induces inflammatory responses and schizophrenia-like phenotypes in mice. View Publication