技术资料

Cardiac ventricular pressure overload affects patients with congenital heart defects and can cause cardiac insufficiency. Grafts of stem cell–derived cardiomyocytes are proposed as a complementary treatment to surgical repair of the cardiac defect,aiming to support ventricular function. Here,we report successful engraftment of human induced pluripotent stem cell–derived cardiac lineage cells into the heart of immunosuppressed rhesus macaques with a novel surgical model of right ventricular pressure overload. The human troponin+ grafts were detected in low-dose (2 × 106 cells/kg) and high-dose (10 × 106 cells/kg) treatment groups up to 12 weeks post-injection. Transplanted cells integrated and progressively matched the organization of the surrounding host myocardium. Ventricular tachycardia occurred in five out of 16 animals receiving cells,with episodes of incessant tachycardia observed in two animals; ventricular tachycardia events resolved within 19 days. Our results demonstrate that grafted cardiomyocytes mature and integrate into the myocardium of nonhuman primates modeling right ventricular pressure overload. View Publication

SummaryMutations in the DMD gene lead to Duchenne muscular dystrophy (DMD),a severe neuromuscular disorder affecting young boys as they acquire motor functions. DMD is typically diagnosed at 2–4 years of age,but the absence of dystrophin has negative impacts on skeletal muscles before overt symptoms appear in patients,which poses a serious challenge in current standards of care. Here,we investigated the consequences of dystrophin deficiency during skeletal muscle development. We used single-cell transcriptome profiling to characterize the myogenic trajectory of human pluripotent stem cells and showed that DMD cells bifurcate to an alternative branch when they reach the somite stage. Dystrophin deficiency was linked to marked dysregulations of cell junction proteins involved in the cell state transitions characteristic of embryonic somitogenesis. Altogether,this work demonstrates that in vitro,dystrophin deficiency has deleterious effects on cell-cell communication during myogenic development,which should be considered in future therapeutic strategies for DMD. Graphical abstract Highlights•Myogenic differentiation of DMD hiPSCs diverges at the somite stage•Cell junction formation is dysregulated in DMD somite cells•Somite cells from DMD hiPSCs have impaired epithelialization properties•Migration velocity of DMD-mutant somite progenitors is upregulated Natural sciences; Biological sciences; Biochemistry; Cell biology; Stem cells research; Developmental biology. View Publication

An intronic G4C2 repeat expansion in the C9ORF72 gene is the major known cause for Amyotrophic Lateral Sclerosis (ALS),with current evidence for both,loss of function and pathological gain of function disease mechanisms. We screened 96 200 small molecules in C9ORF72 patient iPS neurons for modulation of nuclear G4C2 RNA foci and identified 82 validated hits,including the Brd4 inhibitor JQ1 as well as novel analogs of Spliceostatin-A,a known modulator of SF3B1,the branch point binding protein of the U2-snRNP. Spliceosome modulation by these SF3B1 targeted compounds recruits SRSF1 to nuclear G4C2 RNA,mobilizing it from RNA foci into nucleocytoplasmic export. This leads to increased repeat-associated non-canonical (RAN) translation and ultimately,enhanced cell toxicity. Our data (i) provide a new pharmacological entry point with novel as well as known,publicly available tool compounds for dissection of C9ORF72 pathobiology in C9ORF72 ALS models,(ii) allowing to differentially modulate RNA foci versus RAN translation,and (iii) suggest that therapeutic RNA foci elimination strategies warrant caution due to a potential storage function,counteracting translation into toxic dipeptide repeat polyproteins. Instead,our data support modulation of nuclear export via SRSF1 or SR protein kinases as possible targets for future pharmacological drug discovery. View Publication

Differentiation approaches to obtain mesenchymal stem cells (MSCs) have gradually developed over the last few decades. The problem is that different protocols give different MSC types,making further research difficult. Here,we tried three different approaches to differentiate embryonic stem cells (ESCs) from early mesoderm to MSCs using serum-containing or xeno-free differentiation medium and observed differences in the cells’ morphology,doubling rate,ability to form colonies,surface marker analysis,and multilineage differentiation potential of the obtained cell lines. We concluded that the xeno-free medium best fits the criteria of MSCs’ morphology,growth kinetics,and surface marker characterization. In contrast,the serum-containing medium gives better potential for further MSC differentiation into osteogenic,chondrogenic,and adipogenic lineages. View Publication

A large number of synaptic proteins have been recurrently associated with complex brain disorders. One of these proteins,the Traf and Nck interacting kinase (TNIK),is a postsynaptic density (PSD) signaling hub,with many variants reported in neurodevelopmental disorder (NDD) and psychiatric disease. While rodent models of TNIK dysfunction have abnormal spontaneous synaptic activity and cognitive impairment,the role of mutations found in patients with TNIK protein deficiency and TNIK protein kinase activity during early stages of neuronal and synapse development has not been characterized. Here,using hiPSC-derived excitatory neurons,we show that TNIK mutations dysregulate neuronal activity in human immature synapses. Moreover,the lack of TNIK protein kinase activity impairs MAPK signaling and protein phosphorylation in structural components of the PSD. We show that the TNIK interactome is enriched in NDD risk factors and TNIK lack of function disrupts signaling networks and protein interactors associated with NDD that only partially overlap to mature mouse synapses,suggesting a differential role of TNIK in immature synapsis in NDD. View Publication

N6-methyladenosine (m6A) is an abundant internal RNA modification that can impact gene expression at both post-transcriptional and transcriptional levels. However,the landscapes and functions of m6A in human brains and neurodegenerative diseases,including Alzheimer’s disease (AD),are under-explored. Here,we examined RNA m6A methylome using total RNA-seq and meRIP-seq in middle frontal cortex of post-mortem brains from individuals with or without AD,which revealed m6A alteration on both mRNAs and various noncoding RNAs. Notably,many promoter-antisense RNAs (paRNAs) displayed cell-type-specific expression and changes in AD,including one produced adjacent to MAPT that encodes the Tau protein. MAPT-paRNA is highly expressed in neurons,and m6A positively controls its expression. In iPSC-derived human excitatory neurons,MAPT-paRNA does not impact the nearby MAPT mRNA,but instead promotes expression of hundreds of neuronal and synaptic genes,and is protective against excitotoxicity. Analysis of single nuclei RNA-DNA interactome in human brains supports that brain paRNAs interact with both cis- and trans-chromosomal target genes to impact their transcription. These data reveal landscapes and functions of noncoding RNAs and m6A in brain gene regulation and AD pathogenesis. This study characterised the landscapes and changes of RNA m6A in brains of individuals with or without Alzheimer’s disease,and revealed roles of a promoter antisense RNA next to MAPT in neuronal gene regulation that promote neuronal survival. View Publication

Biallelic mutations in PIGK cause GPI biosynthesis defect 22 (GPIBD22),characterized with developmental delay,hypotonia,and cerebellar atrophy. The understanding of the underlying causes is limited due to the lack of suitable disease models. To address this gap,we generated a mouse model with PIGK deficits,specifically in Purkinje cells (Pcp2-cko) and an induced pluripotent stem cell (iPSC) model using the c.87dupT mutant (KI) found in GPIBD22 patients. Pcp2-cko mice demonstrated cerebellar atrophy,ataxia and progressive Purkinje cells loss which were accompanied by increased apoptosis and neuroinflammation. Similarly,KI iPSCs exhibited increased apoptosis and accelerated neural rosette formation,indicating that PIGK defects could impact early neural differentiation that confirmed by the RNA-Seq results of neural progenitor cells (NPCs). The increased apoptosis and accelerated NPC differentiation in KI iPSCs are associated with excessive unfolded protein response (UPR) pathway activation,and can be rescued by UPR pathway inhibitor. Our study reveals potential pathogenic mechanism of GPIBD22 and providing new insights into the therapeutic strategy for GPIBD. View Publication

ABSTRACTHuman induced pluripotent stem cells (iPSCs) are an invaluable endless cell source for generating various therapeutic cells and tissues. However,their differentiation into specific cell lineages,such as definitive endoderm (DE) and pancreatic progenitor (PP),often suffers from poor reproducibility,due partially to their pluripotency. In this work,we investigated the impact of iPSC confluency during cell self?renewal and seeding density on cell metabolic activity,glycolysis to oxidative phosphorylation shift,and differentiation potential toward DE and PP lineages. Our findings demonstrated that cell seeding strategy influences cellular metabolic activity and the robustness of iPSC differentiation. iPSCs maintained at higher seeding density exhibited lower initial oxygen consumption rate (OCR) and metabolic activity. There is an optimal seeding density to ensure sufficient oxygen consumption during differentiation and to yield high expression of SOX17 in the DE lineage and high PDX1/NKX6.1 dual?positive cells in PPs. Interestingly,we found that cell confluency at the time of harvest has less impact on the efficacy of pancreatic lineage formation or metabolic activity. This study sheds light on the interplay between metabolic activity and iPSC lineage specification,offering new insights into the robustness of iPSC self?renewal and differentiation for creating human tissues. Graphical Abstract and Lay SummaryHuman induced pluripotent stem cell (iPSC) differentiation into specific cell lineages often shows poor reproducibility due to cell pluripotency. This study demonstrated impact of iPSC seeding strategy on metabolic activity and differentiation potential,offering new insights into the robustness of iPSC self?renewal and differentiation for creating human tissues. View Publication

Human genetics analysis has identified many noncoding SNPs associated with diabetic traits,but whether and how these variants contribute to diabetes is largely unknown. Here,we focus on a noncoding variant,rs6048205,and report that the risk-G variant impairs the generation of PDX1+/NKX6-1+ pancreatic progenitor cells and further results in the abnormal decrease of functional ? cells during pancreatic differentiation. Mechanistically,this risk-G variant greatly enhances RXRA binding and over-activates FOXA2 transcription,specifically in the pancreatic progenitor stage,which in turn represses NKX6-1 expression. Consistently,inducible FOXA2 overexpression could phenocopy the differentiation defect. More importantly,mice carrying risk-G exhibit abnormal pancreatic islet architecture and are more sensitive to streptozotocin or a high-fat diet to develop into diabetes eventually. This study not only identifies a causal noncoding variant in diabetes susceptibility but also dissects the underlying gain-of-function mechanism by recruiting stage-specific factors. How GWAS-annotated noncoding SNPs contribute to diabetes remains unclear. Here,the authors report that the noncoding SNP rs6048205 drives stage-specific defects in human pancreatic differentiation and increases diabetes susceptibility in mice. View Publication

The emergence of drug-resistant Mycobacterium tuberculosis (M.tb) has led to the development of novel anti-tuberculosis (anti-TB) drugs. Common methods for testing the efficacy of new drugs,including two-dimensional cell culture models or animal models,have several limitations. Therefore,an appropriate model representative of the human organism is required. Here,we developed an M.tb infection model using human lung organoids (hLOs) and demonstrated that M.tb H37Rv can infect lung epithelial cells and human macrophages (hM?s) in hLOs. This novel M.tb infection model can be cultured long-term and split several times while maintaining a similar number of M.tb H37Rv inside the hLOs. Anti-TB drugs reduced the intracellular survival of M.tb in hLOs. Notably,M.tb growth in hLOs was effectively suppressed at each passage by rifampicin and bedaquiline. Furthermore,a reduction in inflammatory cytokine production and intracellular survival of M.tb were observed upon knockdown of MFN2 and HERPUD1 (host-directed therapeutic targets for TB) in our M.tb H37Rv-infected hLO model. Thus,the incorporation of hM?s and M.tb into hLOs provides a powerful strategy for generating an M.tb infection model. This model can effectively reflect host-pathogen interactions and be utilized to test the efficacy of anti-TB drugs and host-directed therapies. Author summaryEstablishment of M.tb infection model is imperative to develop new anti-TB drugs based on the pathogenesis of TB. Various animal models,including mice,rats,guinea pigs,non-human primates,rabbits,cattle,and zebrafish,are commonly used in TB research to mimic TB symptoms and study immune responses to M.tb infection. In vitro models,such as agent-based models allow examination of host-pathogen interactions,early granuloma formation and drug screening,providing cellular-level insights. However,these models may not fully represent human immunopathology owing to differences in immune cell distributions. Lung organoids mimic human lung dynamics and functions,providing crucial insights into immune responses to TB. In this study,an M.tb infection model developed using hLOs demonstrated infection of lung epithelial cells and human macrophages,reflecting host-pathogen interactions. This model is attractive for evaluating the efficacy of anti-TB drugs and host-directed therapies. View Publication

SummaryThe BAF chromatin remodeler regulates lineage commitment including cranial neural crest cell (CNCC) specification. Variants in BAF subunits cause Coffin-Siris syndrome (CSS),a congenital disorder characterized by coarse craniofacial features and intellectual disability. Approximately 50% of individuals with CSS harbor variants in one of the mutually exclusive BAF subunits,ARID1A/ARID1B. While Arid1a deletion in mouse neural crest causes severe craniofacial phenotypes,little is known about the role of ARID1A in CNCC specification. Using CSS-patient-derived ARID1A+/? induced pluripotent stem cells to model CNCC specification,we discovered that ARID1A-haploinsufficiency impairs epithelial-to-mesenchymal transition (EMT),a process necessary for CNCC delamination and migration from the neural tube. Furthermore,wild-type ARID1A-BAF regulates enhancers associated with EMT genes. ARID1A-BAF binding at these enhancers is impaired in heterozygotes while binding at promoters is unaffected. At the sequence level,these EMT enhancers contain binding motifs for ZIC2,and ZIC2 binding at these sites is ARID1A-dependent. When excluded from EMT enhancers,ZIC2 relocates to neuronal enhancers,triggering aberrant neuronal gene activation. In mice,deletion of Zic2 impairs NCC delamination,while ZIC2 overexpression in chick embryos at post-migratory neural crest stages elicits ectopic delamination from the neural tube. These findings reveal an essential ARID1A-ZIC2 axis essential for EMT and CNCC delamination. Graphical abstract ARID1A modulates chromatin accessibility at enhancers of genes required for epithelial-to-mesenchymal transition,a process essential for cranial neural crest cell (CNCC) specification. Haploinsufficiency of ARID1A attenuates ZIC2 binding at these enhancers,resulting in impaired CNCC formation with an aberrant neuronal trajectory. This study reveals an ARID1A-ZIC2 axis essential for CNCC specification. View Publication

Diabetes involves the death or dysfunction of pancreatic ?-cells. Analysis of bulk sequencing from human samples and studies using in vitro and in vivo models suggest that endoplasmic reticulum and inflammatory signaling play an important role in diabetes progression. To better characterize cell type-specific stress response,we perform multiplexed single-cell RNA sequencing to define the transcriptional signature of primary human islet cells exposed to endoplasmic reticulum and inflammatory stress. Through comprehensive pair-wise analysis of stress responses across pancreatic endocrine and exocrine cell types,we define changes in gene expression for each cell type under different diabetes-associated stressors. We find that ?-,?-,and ductal cells have the greatest transcriptional response. We utilize stem cell-derived islets to study islet health through the candidate gene CIB1,which was upregulated under stress in primary human islets. Our findings provide insights into cell type-specific responses to diabetes-associated stress and establish a resource to identify targets for diabetes therapeutics. Endoplasmic reticulum and inflammatory stress are associated with diabetes. Maestas et al. use single-cell sequencing to profile primary human islets under stress and identified tissue and cell-type responses. View Publication