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A growing body of clinical literature has described neurodevelopmental delays in infants with chronic prenatal opioid exposure and withdrawal. Despite this,the mechanism of how opioids impact the developing brain remains unknown. Here,we developed an in vitro model of prenatal morphine exposure and withdrawal using healthy human induced pluripotent stem cell (iPSC)-derived midbrain neural progenitors in monolayer. To optimize our model,we identified that a longer neural induction and regional patterning period increases expression of canonical opioid receptors mu and kappa in midbrain neural progenitors compared to a shorter protocol (OPRM1,two-tailed t-test,p =? 0.004; OPRK1,p =? 0.0003). Next,we showed that the midbrain neural progenitors derived from a longer iPSC neural induction also have scant toll-like receptor 4 (TLR4) expression,a key player in neonatal opioid withdrawal syndrome pathophysiology. During morphine withdrawal,differentiating neural progenitors experience cyclic adenosine monophosphate overshoot compared to cell exposed to vehicle (p =? 0.0496) and morphine exposure conditions (p,=? 0.0136,1-way ANOVA). Finally,we showed that morphine exposure and withdrawal alters proportions of differentiated progenitor cell fates (2-way ANOVA,F =? 16.05,p View Publication

ABSTRACTMedium chain acyl?CoA dehydrogenase deficiency (MCADD) is an inherited metabolic disease,characterized by biallelic variants in the ACADM gene. Interestingly,even with the same genotype,patients often present with very heterogeneous symptoms,ranging from fully asymptomatic to life?threatening hypoketotic hypoglycemia. The mechanisms underlying this heterogeneity remain unclear. Therefore,there is a need for in vitro models of MCADD that recapitulate the clinical phenotype as a tool to study the pathophysiology of the disease. Fibroblasts of control and symptomatic MCADD patients with the c.985A>G (p.K329E) were reprogrammed into induced pluripotent stem cells (iPSCs). iPSCs were then differentiated into hepatic expandable organoids (EHOs),further matured to Mat?EHOs,and functionally characterized. EHOs and Mat?EHOs performed typical hepatic metabolic functions,such as albumin and urea production. The organoids metabolized fatty acids,as confirmed by acyl?carnitine profiling and high?resolution respirometry. MCAD protein was fully ablated in MCADD organoids,in agreement with the instability of the mutated MCAD protein. MCADD organoids accumulated medium?chain acyl?carnitines,with a strongly elevated C8/C10 ratio,characteristic of the biochemical phenotype of the disease. Notably,C2 and C14 acyl?carnitines were found decreased in MCADD Mat?EHOs. Finally,MCADD organoids exhibited differential expression of genes involved in ??oxidation,mitochondrial ??oxidation,TCA cycle,and peroxisomal coenzyme A metabolism,particularly upregulation of NUDT7. iPSC?derived organoids of MCADD patients recapitulated the major biochemical phenotype of the disease. Mat?EHOs expressed relevant pathways involved in putative compensatory mechanisms,notably CoA metabolism and the TCA cycle. The upregulation of NUDT7 expression may play a role in preventing excessive accumulation of dicarboxylic acids in MCADD. This patient?specific hepatic organoid system is a promising platform to study the phenotypic heterogeneity between MCADD patients. 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

The neuromuscular junction (NMJ) is essential for transmitting signals from motor neurons (MNs) to skeletal muscles (SKMs),and its dysfunction can lead to severe motor disorders. However,our understanding of the NMJ is limited by the absence of accurate human models. Although human induced pluripotent stem cell (iPSC)-derived models have advanced NMJ research,their application is constrained by challenges such as limited differentiation efficiency,lengthy generation times,and cryopreservation difficulties. To overcome these limitations,we developed a rapid human NMJ model using cryopreserved MNs and SKMs derived from iPSCs. Within 12 days of coculture,we successfully recreated NMJ-specific connectivity that closely mirrors in vivo synapse formation. Using this model,we investigated amyotrophic lateral sclerosis (ALS) and replicated ALS-specific NMJ cytopathies with SOD1 mutant and corrected isogenic iPSC lines. Quantitative analysis of 3D confocal microscopy images revealed a critical role of MNs in initiating ALS-related NMJ cytopathies,characterized by alterations in the volume,number,intensity,and distribution of acetylcholine receptors,ultimately leading to impaired muscle contractions. Our rapid and precise in vitro NMJ model offers significant potential for advancing research on NMJ physiology and pathology,as well as for developing treatments for NMJ-related diseases. View Publication

Interactions between adipose tissue,liver and immune system are at the center of metabolic dysfunction-associated steatotic liver disease and type 2 diabetes. To address the need for an accurate in vitro model,we establish an interconnected microphysiological system (MPS) containing white adipocytes,hepatocytes and proinflammatory macrophages derived from isogenic human induced pluripotent stem cells. Using this MPS,we find that increasing the adipocyte-to-hepatocyte ratio moderately affects hepatocyte function,whereas macrophage-induced adipocyte inflammation causes lipid accumulation in hepatocytes and MPS-wide insulin resistance,corresponding to initiation of metabolic dysfunction-associated steatotic liver disease. We also use our MPS to identify and characterize pharmacological intervention strategies for hepatic steatosis and systemic insulin resistance and find that the glucagon-like peptide-1 receptor agonist semaglutide improves hepatocyte function by acting specifically on adipocytes. These results establish our MPS modeling the adipose tissue-liver axis as an alternative to animal models for mechanistic studies or drug discovery in metabolic diseases. In vitro modelling of the adipose tissue-liver axis can advance understanding and therapy of metabolic disease,including by distinguishing effects of obesity and inflammation. Here,authors develop such a system based on isogenic human iPSCs and interconnected microphysiological devices. View Publication

Krabbe disease (Kd) is a lysosomal storage disorder (LSD) caused by the deficiency of the lysosomal galactosylceramidase (GALC) which cleaves the myelin enriched lipid galactosylceramide (GalCer). Accumulated GalCer is catabolized into the cytotoxic lipid psychosine that causes myelinating cells death and demyelination which recruits microglia/macrophages that fail to digest myelin debris and become globoid cells. Here,to understand the pathological mechanisms of Kd,we used induced pluripotent stem cells (iPSCs) from Kd patients to produce myelinating organoids and microglia. We show that Kd organoids have no obvious defects in neurogenesis,astrogenesis,and oligodendrogenesis but manifest early myelination defects. Specifically,Kd organoids showed shorter but a similar number of myelin internodes than Controls at the peak of myelination and a reduced number and shorter internodes at a later time point. Interestingly,myelin is affected in the absence of autophagy and mTOR pathway dysregulation,suggesting lack of lysosomal dysfunction which makes this organoid model a very valuable tool to study the early events that drive demyelination in Kd. Kd iPSC-derived microglia show a marginal rate of globoid cell formation under normal culture conditions that is drastically increased upon GalCer feeding. Under normal culture conditions,Kd microglia show a minor LAMP1 content decrease and a slight increase in the autophagy protein LC3B. Upon GalCer feeding,Kd cells show accumulation of autophagy proteins and strong LAMP1 reduction that at a later time point are reverted showing the compensatory capabilities of globoid cells. Altogether,this supports the value of our cultures as tools to study the mechanisms that drive globoid cell formation and the compensatory mechanism in play to overcome GalCer accumulation in Kd. View Publication

PIEZO1 is critical to numerous physiological processes,transducing diverse mechanical stimuli into electrical and chemical signals. Recent studies underscore the importance of visualizing endogenous PIEZO1 activity and localization to understand its functional roles. To enable physiologically and clinically relevant studies on human PIEZO1,we genetically engineered human induced pluripotent stem cells (hiPSCs) to express a HaloTag fused to endogenous PIEZO1. Combined with advanced imaging,our chemogenetic platform allows precise visualization of PIEZO1 localization dynamics in various cell types. Furthermore,the PIEZO1-HaloTag hiPSC technology facilitates the non-invasive monitoring of channel activity across diverse cell types using Ca2+-sensitive HaloTag ligands,achieving temporal resolution approaching that of patch clamp electrophysiology. Finally,we use lightsheet microscopy on hiPSC-derived neural organoids to achieve molecular scale imaging of PIEZO1 in three-dimensional tissue. Our advances establish a platform for studying PIEZO1 mechanotransduction in human systems,with potential for elucidating disease mechanisms and targeted drug screening. PIEZO1 is critical in numerous physiological processes,but monitoring its activity and localization in cells can be challenging. Here,the authors present a chemogenetic platform to visualize endogenous human PIEZO1 localization and activity in native cellular conditions,expanding the knowledge on mechanotransduction across single cells and tissue organoids. View Publication

Natural killer (NK) cells are cytotoxic immune cells that can eliminate target cells without prior stimulation. Human induced pluripotent stem cells (iPSCs) provide a robust source of NK cells for safe and effective cell-based immunotherapy against aggressive cancers. In this in vitro study,a feeder-free iPSC differentiation was performed to obtain iPSC-NK cells,and distinct maturational stages of iPSC-NK were characterized. Mature cells of CD56bright CD16bright phenotype showed upregulation of CD56,CD16,and NK cell activation markers NKG2D and NKp46 upon IL-15 exposure,while exposure to aggressive atypical teratoid/rhabdoid tumor (ATRT) cell lines enhanced NKG2D and NKp46 expression. Malignant cell exposure also increased CD107a degranulation markers and stimulated IFN-? secretion in activated NK cells. CD56bright CD16bright iPSC-NK cells showed a ratio-dependent killing of ATRT cells,and the percentage lysis of CHLA-05-ATRT was higher than that of CHLA-02-ATRT. The iPSC-NK cells were also cytotoxic against other brain,kidney,and lung cancer cell lines. Further NK maturation yielded CD56?ve CD16bright cells,which lacked activation markers even after exposure to interleukins or ATRT cells - indicating diminished cytotoxicity. Generation and characterization of different NK phenotypes from iPSCs,coupled with their promising anti-tumor activity against ATRT in vitro,offer valuable insights into potential immunotherapeutic strategies for brain tumors. Graphical abstractImage 1 Highlights•Natural killer (NK) cells were derived from human induced pluripotent stem cells (iPSCs) in the absence of feeder cells.•Various maturational subtypes of iPSC-NK cells were characterized,and the phenotypic and functional properties were studied.•iPSC-NK cells of CD56bright CD16bright phenotype expressed activation markers in response to interleukin stimuli.•iPSC-NK cells were cytotoxic toward human atypical teratoid and rhabdoid tumor (ATRT) cells and other human cancer cells.•The cytotoxicity of iPSC-NK cells against various cancer cells in vitro might be translated into an in vivo immunotherapy. View Publication

SummaryAlthough chimeric antigen receptor (CAR) T cells have demonstrated therapeutic activity in hematopoietic malignancies,tumor heterogeneity has impeded the efficacy of CAR T cells and their extension into successful solid tumor treatment. To address these challenges,induced pluripotent stem cell (iPSC)-derived T (iT) cells are engineered to uniformly express CAR and T cell receptor (TCR),enabling targeting of both surface and intracellular antigens,respectively,along with a high-affinity,non-cleavable variant of CD16a (hnCD16) to support antibody-dependent cellular cytotoxicity (ADCC) when combined with therapeutic antibodies. Co-expression of each antitumor strategy on engineered iT cells enables independent and antigen-specific targeting across a diverse set of liquid and solid tumors. In heterogeneous tumor models,coactivation of these modalities is required for measurable antitumor efficacy,with activation of all three modalities displaying maximal efficacy. These data highlight the therapeutic potential of an off-the-shelf engineered iPSC-derived trimodal T cell expressing CAR,TCR,and hnCD16 to combat difficult-to-treat heterogeneous tumors. Graphical abstract Highlights•CAR,TCR,and hnCD16 can be uniformly co-expressed and can function in iT cells•hnCD16 signals through CD3ζ and arms iT cells with targeting flexibility through ADCC•Concurring CAR,TCR,and hnCD16 activation demonstrates a cooperative effect•Multi-targeting with trimodal iT cells can control heterogeneous tumors in vivo Yang et al. show that (1) trimodal iPSC cells expressing CAR,TCR,and hnCD16 can commit to T cell lineage,(2) hnCD16 signals through CD3ζ in iT cells and arms iT cells with ADCC targeting flexibility,and (3) trimodal iT cells control antigen-heterogeneous tumors in vivo through multi-modal targeting. View Publication

Human induced pluripotent stem cell (hiPSC) derived neurons are powerful tools to model disease biology in the drug development space. Here we leveraged a spectrum of neurophysiological tools to characterize iPSC-derived NGN2 neurons. Specifically,we applied these technologies to detect phenotypes associated with presynaptic dysfunction and rescue in NGN2 neurons lacking a synaptic vesicle associated protein MUNC18-1,encoded by syntaxin binding protein 1 gene (STXBP1). STXBP1 homozygous knock out NGN2 neurons lacked miniature post synaptic currents and demonstrated disrupted network bursting as assayed with multielectrode array and calcium imaging. Furthermore,knock out neurons released less glutamate into culture media,consistent with a presynaptic deficit. These synaptic phenotypes were rescued by reconstitution of STXBP1 protein by AAV transduction in a dose-dependent manner. Our results identify a complementary suite of physiological methods suitable to examine the modulation of synaptic transmission in human neurons. View Publication

The transplantation of spinal cord progenitor cells (SCPCs) derived from human-induced pluripotent stem cells (iPSCs) has beneficial effects in treating spinal cord injury (SCI). However,the presence of residual undifferentiated iPSCs among their differentiated progeny poses a high risk as these cells can develop teratomas or other types of tumors post-transplantation. Despite the need to remove these residual undifferentiated iPSCs,no specific surface markers can identify them for subsequent removal. By profiling the size of SCPCs after a 10-day differentiation process,we found that the large-sized group contains significantly more cells expressing pluripotent markers. In this study,we used a sized-based,label-free separation using an inertial microfluidic-based device to remove tumor-risk cells. The device can reduce the number of undifferentiated cells from an SCPC population with high throughput (ie,>3 million cells/minute) without affecting cell viability and functions. The sorted cells were verified with immunofluorescence staining,flow cytometry analysis,and colony culture assay. We demonstrated the capabilities of our technology to reduce the percentage of OCT4-positive cells. Our technology has great potential for the “downstream processing” of cell manufacturing workflow,ensuring better quality and safety of transplanted cells. View Publication

The use of genetic engineering to generate point mutations in induced pluripotent stem cells (iPSCs) is essential for studying a specific genetic effect in an isogenic background. We demonstrate that a combination of p53 inhibition and pro-survival small molecules achieves a homologous recombination rate higher than 90% using Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) in human iPSCs. Our protocol reduces the effort and time required to create isogenic lines. View Publication