技术资料

Evolutionary innovations can be driven by changes in the rates of RNA translation and the emergence of new genes and small open reading frames (sORFs). In this study,we characterized the transcriptional and translational landscape of the hearts of four primate and two rodent species through integrative ribosome and transcriptomic profiling,including adult left ventricle tissues and induced pluripotent stem cell-derived cardiomyocyte cell cultures. We show here that the translational efficiencies of subunits of the mitochondrial oxidative phosphorylation chain complexes IV and V evolved rapidly across mammalian evolution. Moreover,we discovered hundreds of species-specific and lineage-specific genomic innovations that emerged during primate evolution in the heart,including 551 genes,504 sORFs and 76 evolutionarily conserved genes displaying human-specific cardiac-enriched expression. Overall,our work describes the evolutionary processes and mechanisms that have shaped cardiac transcription and translation in recent primate evolution and sheds light on how these can contribute to cardiac development and disease. Ruiz-Orera et al. used comparative transcriptomics and translatomics to analyze the cardiac evolution in primates and discovered species-specific and lineage-specific genomic innovations that might contribute to cardiac development and disease. View Publication

Friedreich ataxia (FRDA) is a multisystemic,autosomal recessive disorder caused by homozygous GAA expansion mutation in the first intron of frataxin (FXN) gene. FXN is a mitochondrial protein critical for iron-sulfur cluster biosynthesis and deficiency impairs mitochondrial electron transport chain functions and iron homeostasis within the organelle. Currently,there is no effective treatment for FRDA. We have previously demonstrated that single infusion of wild-type hematopoietic stem and progenitor cells (HSPCs) resulted in prevention of neurologic and cardiac complications of FRDA in YG8R mice,and rescue was mediated by FXN transfer from tissue engrafted,HSPC-derived microglia/macrophages to diseased neurons/myocytes. For a future clinical translation,we developed an autologous stem cell transplantation approach using CRISPR/Cas9 for the excision of the GAA repeats in FRDA patients’ CD34+ HSPCs; this strategy leading to increased FXN expression and improved mitochondrial functions. The aim of the current study is to validate the efficiency and safety of our gene editing approach in a disease-relevant model. We generated a cohort of FRDA patient-derived iPSCs and isogenic lines that were gene edited with our CRISPR/Cas9 approach. iPSC derived FRDA neurons displayed characteristic apoptotic and mitochondrial phenotype of the disease,such as non-homogenous microtubule staining in neurites,increased caspase-3 expression,mitochondrial superoxide levels,mitochondrial fragmentation,and partial degradation of the cristae compared to healthy controls. These defects were fully prevented in the gene edited neurons. RNASeq analysis of FRDA and gene edited neurons demonstrated striking improvement in gene clusters associated with endoplasmic reticulum (ER) stress in the isogenic lines. Gene edited neurons demonstrated improved ER-calcium release,normalization of ER stress response gene,XBP-1,and significantly increased ER-mitochondrial contacts that are critical for functional homeostasis of both organelles,as compared to FRDA neurons. Ultrastructural analysis for these contact sites displayed severe ER structural damage in FRDA neurons,that was undetected in gene edited neurons. Taken together,these results represent a novel finding for disease pathogenesis showing dramatic ER structural damage in FRDA,validate the efficacy profile of our FXN gene editing approach in a disease relevant model,and support our approach as an effective strategy for therapeutic intervention for Friedreich’s ataxia. View Publication

Diabetes mellitus,a chronic and non-transmissible disease,triggers a wide range of micro- and macrovascular complications. The differentiation of pancreatic ?-like cells (P?LCs) from induced pluripotent stem cells (iPSCs) offers a promising avenue for regenerative medicine aimed at treating diabetes. Current differentiation protocols strive to emulate pancreatic embryonic development by utilizing cytokines and small molecules at specific doses to activate and inhibit distinct molecular signaling pathways,directing the differentiation of iPSCs into pancreatic ? cells. Despite significant progress and improved protocols,the full spectrum of molecular signaling pathways governing pancreatic development and the physiological characteristics of the differentiated cells are not yet fully understood. Here,we report a specific combination of cofactors and small molecules that successfully differentiate iPSCs into P?LCs. Our protocol has shown to be effective,with the resulting cells exhibiting key functional properties of pancreatic ? cells,including the expression of crucial molecular markers (pdx1,nkx6.1,ngn3) and the capability to secrete insulin in response to glucose. Furthermore,the addition of vitamin C and retinoic acid in the final stages of differentiation led to the overexpression of specific ? cell genes. View Publication

SummaryCell size is a crucial physical property that significantly impacts cellular physiology and function. However,the influence of cell size on stem cell specification remains largely unknown. Here,we investigated the dynamic changes in cell size during the differentiation of human pluripotent stem cells into definitive endoderm (DE). Interestingly,cell size exhibited a gradual decrease as DE differentiation progressed with higher stiffness. Furthermore,the application of hypertonic pressure or chemical to accelerate the reduction in cell size significantly and specifically enhanced DE differentiation. By functionally intervening in mechanosensitive elements,we have identified actomyosin activity as a crucial mediator of both DE differentiation and cell size reduction. Mechanistically,the reduction in cell size induces actomyosin-dependent angiomotin (AMOT) nuclear translocation,which suppresses Yes-associated protein (YAP) activity and thus facilitates DE differentiation. Together,our study has established a novel connection between cell size diminution and DE differentiation,which is mediated by AMOT nuclear translocation. Additionally,our findings suggest that the application of osmotic pressure can effectively promote human endodermal lineage differentiation. Graphical abstract Highlights•Cell size decreases during the differentiation of human pluripotent stem cells into endoderm•Hypertonic pressure is conducive to the differentiation of human definitive endoderm•Actomyosin contributes to both size diminution and endoderm promotion under hypertonic pressure•Cell size diminution represses YAP activity via promoting AMOT nuclear translocation Jiang and colleagues show that cell size exhibits a gradual decrease during human endoderm differentiation. The application of hypertonic pressure or chemical to accelerate the reduction in cell size significantly and specifically enhanced endoderm differentiation. This enhancement is reliant on actomyosin activity and achieved by promoting the nuclear translocation of AMOT,thereby repressing YAP activity. View Publication

Disease modeling with isogenic Induced Pluripotent Stem Cell (iPSC)-differentiated organoids serves as a powerful technique for studying disease mechanisms. Multiplexed coculture is crucial to mitigate batch effects when studying the genetic effects of disease-causing variants in differentiated iPSCs or organoids,and demultiplexing at the single-cell level can be conveniently achieved by assessing natural genetic barcodes. Here,to enable cost-efficient time-series experimental designs via multiplexed bulk and single-cell RNA-seq of hybrids,we introduce a computational method in our Vireo Suite,Vireo-bulk,to effectively deconvolve pooled bulk RNA-seq data by genotype reference,and thereby quantify donor abundance over the course of differentiation and identify differentially expressed genes among donors. Furthermore,with multiplexed scRNA-seq and bulk RNA-seq,we demonstrate the usefulness and necessity of a pooled design to reveal donor iPSC line heterogeneity during macrophage cell differentiation and to model rare WT1 mutation-driven kidney disease with chimeric organoids. Our work provides an experimental and analytic pipeline for dissecting disease mechanisms with chimeric organoids. IPSC-derived organoids model diseases. Multiplexed coculture and demultiplexing natural genetic barcodes aid in studying genetic effects. Here,authors introduce Vireo-bulk to deconvolve bulk RNA-seq data,quantify donor abundance and identify differentially expressed genes. View Publication

Repressor element-1 silencing transcription factor (REST) is a transcriptional repressor involved in neurodevelopment and neuroprotection. REST forms a complex with the REST corepressors,CoREST1,CoREST2,or CoREST3 (encoded by RCOR1,RCOR2,and RCOR3,respectively). Emerging evidence suggests that the CoREST family can target unique genes independently of REST,in various neural and glial cell types during different developmental stages. However,there is limited knowledge regarding the expression and function of the CoREST family in human neurodevelopment. To address this gap,we employed 2D and 3D human pluripotent stem cell (hPSC) models to investigate REST and RCOR gene expression levels. Our study revealed a significant increase in RCOR3 expression in glutamatergic cortical and GABAergic ventral forebrain neurons,as well as mature functional NGN2-induced neurons. Additionally,a simplified astrocyte transdifferentiation protocol resulted in a significant decrease in RCOR2 expression following differentiation. REST expression was notably reduced in mature neurons and cerebral organoids. In summary,our findings provide the first insights into the cell-type-specific expression patterns of RCOR genes in human neuronal and glial differentiation. Specifically,RCOR3 expression increases in neurons,while RCOR2 levels decrease in astrocytes. The dynamic expression patterns of REST and RCOR genes during hPSC neuronal and glial differentiation underscore the potential distinct roles played by REST and CoREST proteins in regulating the development of these cell types in humans. Graphical abstractImage 1 Highlights•REST and RCOR genes display cell-type specific expression patterns in neural cells.•RCOR3 (encodes CoREST3) is upregulated during neuronal and astrocyte differentiation.•RCOR2 (encodes CoREST2) is downregulated during differentiation of astrocytes.•Evidence of potential cell-type specific functions of the CoREST family. View Publication

High-throughput massively parallel reporter assays (MPRAs) and phenotype-rich in vivo transgenic mouse assays are two potentially complementary ways to study the impact of noncoding variants associated with psychiatric diseases. Here,we investigate the utility of combining these assays. Specifically,we carry out an MPRA in induced human neurons on over 50,000 sequences derived from fetal neuronal ATAC-seq datasets and enhancers validated in mouse assays. We also test the impact of over 20,000 variants,including synthetic mutations and 167 common variants associated with psychiatric disorders. We find a strong and specific correlation between MPRA and mouse neuronal enhancer activity. Four out of five tested variants with significant MPRA effects affected neuronal enhancer activity in mouse embryos. Mouse assays also reveal pleiotropic variant effects that could not be observed in MPRA. Our work provides a catalog of functional neuronal enhancers and variant effects and highlights the effectiveness of combining MPRAs and mouse transgenic assays. MPRAs and in vivo transgenic mouse assays are two potentially complementary ways to assay the impact of noncoding variants. Here,authors find a strong and specific correlation between the assays in neural cells. Mouse assays also reveal pleiotropic effects not observed in MPRA. View Publication

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of the motor system with complex determinants,including genetic and non-genetic factors. A key pathological signature of ALS is the cytoplasmic mislocalization and aggregation of TDP-43 in affected motor neurons,which is found in 97% of cases. Recent reports have shown that mitochondrial dysfunction plays a significant role in motor neuron degeneration in ALS,and TDP-43 modulates several mitochondrial transcripts. In this study,we used induced pluripotent stem cell-derived motor neurons from ALS patients with TDP-43 mutations and a transgenic TDP-43M337V mouse model to determine how TDP-43 mutations alter mitochondrial function and axonal transport. We detected significantly reduced mitochondrial respiration and ATP production in patient induced pluripotent stem cell-derived motor neurons,linked to an interaction between TDP-43M337V with ATPB and COX5A. A downstream reduction in speed of retrograde axonal transport in patient induced pluripotent stem cell-derived motor neurons was detected,which correlated with downregulation of the motor protein complex,DCTN1/dynein. Overexpression of DCTN1 in patient induced pluripotent stem cell-derived motor neurons significantly increased the percentage of retrograde travelling mitochondria and reduced the percentage of stationary mitochondria. This study shows that ALS induced pluripotent stem cell-derived motor neurons with mutations in TDP-43 have deficiencies in essential mitochondrial functions with downstream effects on retrograde axonal transport,which can be partially rescued by DCTN1 overexpression. Dafinca et al. show that mutations in TDP-43 lead to decreased mitochondrial oxidative phosphorylation,partially due to interactions with the ATP production machinery and COX5A. These have direct effects on axonal transport,which is reduced in amyotrophic lateral sclerosis motor neurons,and overexpression of dynactin-1 significantly increases retrograde mitochondrial dynamics. View Publication

ABSTRACTObjectivesAutism spectrum disorder (ASD) is a neurodevelopmental condition that affects social communication and behaviors. While previous studies using animal models have substantially expanded our knowledge about ASD,the lack of an appropriate human model system that accurately recapitulates the human?specific pathophysiology of ASD hinders the precise understanding of its etiology and the development of effective therapies. This study aims to replicate pathological phenotypes in cerebral organoids derived from idiopathic ASD patients and to conduct proof?of?concept research for the development of ASD therapeutics.MethodsWe conducted an in vitro disease modeling study using cerebral organoids derived from three idiopathic ASD patients. Additionally,we performed organoid?based phenotypic drug screening to identify potential therapeutic compounds that could ameliorate the phenotypes observed in cerebral organoids derived from idiopathic ASD patients.ResultsHere we show that cerebral organoids derived from idiopathic ASD patients display malformation of the ventricular zones and impaired early neuronal differentiation. Through organoid?based phenotypic drug screening,we successfully generated cerebral organoids with normal tissue architecture in which the delayed neuronal differentiation could also be accelerated. Notably,cerebral organoids from ASD patients exhibited a reduced number of GABAergic neurons compared to healthy controls,resulting in an imbalance in the excitatory and inhibitory neuron ratio. The differentiation defects into GABAergic neurons in patient?derived cerebral organoids could be rescued by treating with either IGF1 or Gabapentin,a GABA agonist.ConclusionsOur findings provide a framework for utilizing patient?derived cerebral organoids in the development of personalized pharmaceutical treatment for ASD. Summary of in vitro disease modeling and drug screening using ASD patient?derived COs. This figure highlights the major phenotypes observed in COASD and the therapeutic effects of each compound screened in this study. View Publication

ABSTRACTThe paradoxical exacerbation of cellular injury and death during reperfusion remains a problem in the treatment of myocardial infarction. Mitochondrial dysfunction plays a key role in the pathogenesis of myocardial ischemia and reperfusion injury. Dysfunctional mitochondria can be removed by mitophagy,culminating in their degradation within acidic lysosomes. Mitophagy is pivotal in maintaining cardiac homeostasis and emerges as a potential therapeutic target. Here,we employed beating human engineered heart tissue (EHT) to assess mitochondrial dysfunction and mitophagy during ischemia and reperfusion simulation. Our data indicate adverse ultrastructural changes in mitochondrial morphology and impairment of mitochondrial respiration. Furthermore,our pH-sensitive mitophagy reporter EHTs,generated by a CRISPR/Cas9 endogenous knock-in strategy,revealed induced mitophagy flux in EHTs after ischemia and reperfusion simulation. The induced flux required the activity of the protein kinase ULK1,a member of the core autophagy machinery. Our results demonstrate the applicability of the reporter EHTs for mitophagy assessment in a clinically relevant setting. Deciphering mitophagy in the human heart will facilitate development of novel therapeutic strategies. Summary: Mitochondrial dysfunction and lysosomal degradation of mitochondria (mitophagy) is induced after ischemia and reperfusion simulation in human engineered heart tissue,as shown with an endogenous pH-sensitive mitophagy reporter. View Publication

Oxidative phosphorylation (OXPHOS) in the mitochondrial inner membrane is a therapeutic target in many diseases. Neural stem cells (NSCs) show progress in improving mitochondrial dysfunction in the central nervous system (CNS). However,translating neural stem cell-based therapies to the clinic is challenged by uncontrollable biological variability or heterogeneity,hindering uniform clinical safety and efficacy evaluations. We propose a systematic top-down design based on membrane self-assembly to develop neural stem cell-derived oxidative phosphorylating artificial organelles (SAOs) for targeting the central nervous system as an alternative to NSCs. We construct human conditionally immortal clone neural stem cells (iNSCs) as parent cells and use a streamlined closed operation system to prepare neural stem cell-derived highly homogenous oxidative phosphorylating artificial organelles. These artificial organelles act as biomimetic organelles to mimic respiration chain function and perform oxidative phosphorylation,thus improving ATP synthesis deficiency and rectifying excessive mitochondrial reactive oxygen species production. Conclusively,we provide a framework for a generalizable manufacturing procedure that opens promising prospects for disease treatment. Regulating oxidative phosphorylation and restoring redox homeostasis are crucial in neurological disorders. Here,the authors develop a top-down membrane self-assembly strategy to develop stem cell-derived artificial organelles (SAOs) that mimic mitochondrial oxidative phosphorylation without the risks associated with stem cell therapy. View Publication

The advancement of Long-Read Sequencing (LRS) techniques has significantly increased the length of sequencing to several kilobases,thereby facilitating the identification of alternative splicing events and isoform expressions. Recently,numerous computational tools for isoform detection using long-read sequencing data have been developed. Nevertheless,there remains a deficiency in comparative studies that systemically evaluate the performance of these tools,which are implemented with different algorithms,under various simulations that encompass potential influencing factors. In this study,we conducted a benchmark analysis of thirteen methods implemented in nine tools capable of identifying isoform structures from long-read RNA-seq data. We evaluated their performances using simulated data,which represented diverse sequencing platforms generated by an in-house simulator,RNA sequins (sequencing spike-ins) data,as well as experimental data. Our findings demonstrate IsoQuant as a highly effective tool for isoform detection with LRS,with Bambu and StringTie2 also exhibiting strong performance. These results offer valuable guidance for future research on alternative splicing analysis and the ongoing improvement of tools for isoform detection using LRS data. Recently,various computational tools have emerged for detecting mRNA isoforms using long-read sequencing data. Here,the authors systemically evaluate and compare the performance of these tools. View Publication