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Poisoning with the organophosphorus nerve agent VX can be life-threatening due to limitations of the standard therapy with atropine and oximes. To date,the underlying pathomechanism of VX affecting the neuromuscular junction has not been fully elucidated structurally. Results of recent studies investigating the effects of VX were obtained from cells of animal origin or immortalized cell lines limiting their translation to humans. To overcome this limitation,motor neurons (MN) of this study were differentiated from in-house feeder- and integration-free-derived human-induced pluripotent stem cells (hiPSC) by application of standardized and antibiotic-free differentiation media with the aim to mimic human embryogenesis as closely as possible. For testing VX sensitivity,MN were initially exposed once to 400 µM,600 µM,800 µM,or 1000 µM VX and cultured for 5 days followed by analysis of changes in viability and neurite outgrowth as well as at the gene and protein level using µLC-ESI MS/HR MS,XTT,IncuCyte,qRT-PCR,and Western Blot. For the first time,VX was shown to trigger neuronal cell death and decline in neurite outgrowth in hiPSC-derived MN in a time- and concentration-dependent manner involving the activation of the intrinsic as well as the extrinsic pathway of apoptosis. Consistent with this,MN morphology and neurite network were altered time and concentration-dependently. Thus,MN represent a valuable tool for further investigation of the pathomechanism after VX exposure. These findings might set the course for the development of a promising human neuromuscular test model and patient-specific therapies in the future. 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

Stem cell-derived ?-cells (SC-BCs) represent a potential source for curing diabetes. To date,in vitro generated SC-BCs display an immature phenotype and lack important features in comparison to their bona-fide counterparts. Transplantation into a living animal promotes SC-BCs maturation,indicating that components of the in vivo microenvironment trigger final SC-BCs development. Here,we investigated whether cues of the pancreas specific extracellular matrix (ECM) can improve the differentiation of human induced pluripotent stem cells (hiPSCs) towards ?-cells in vitro. To this aim,a pancreas specific ECM (PanMa) hydrogel was generated from decellularized porcine pancreas and its effect on the differentiation of hiPSC-derived pancreatic hormone expressing cells (HECs) was tested. The hydrogel solidified upon neutralization at 37 °C with gelation kinetics similar to Matrigel. Cytocompatibility of the PanMa hydrogel was demonstrated for a culture duration of 21 days. Encapsulation and culture of HECs in the PanMa hydrogel over 7 days resulted in a stable gene and protein expression of most ?-cell markers,but did not improve ?-cell identity. In conclusion,the study describes the production of a PanMa hydrogel,which provides the basis for the development of ECM hydrogels that are more adapted to the demands of SC-BCs. View Publication

BackgroundAtrial fibrillation has an estimated prevalence of 1.5–2%,making it the most common cardiac arrhythmia. The processes that cause and sustain the disease are still not completely understood. An association between atrial fibrillation and systemic,as well as local,inflammatory processes has been reported. However,the exact mechanisms underlying this association have not been established. While it is understood that inflammatory macrophages can influence cardiac electrophysiology,a direct,causative relationship to atrial fibrillation has not been described. This study investigated the pro-arrhythmic effects of activated M1 macrophages on human induced pluripotent stem cell (hiPSC)-derived atrial cardiomyocytes,to propose a mechanistic link between inflammation and atrial fibrillation.MethodsTwo hiPSC lines from healthy individuals were differentiated to atrial cardiomyocytes and M1 macrophages and integrated in an isogenic,pacing-free,atrial fibrillation-like coculture model. Electrophysiology characteristics of cocultures were analysed for beat rate irregularity,electrogram amplitude and conduction velocity using multi electrode arrays. Cocultures were additionally treated using glucocorticoids to suppress M1 inflammation. Bulk RNA sequencing was performed on coculture-isolated atrial cardiomyocytes and compared to meta-analyses of atrial fibrillation patient transcriptomes.ResultsMulti electrode array recordings revealed M1 to cause irregular beating and reduced electrogram amplitude. Conduction analysis further showed significantly lowered conduction homogeneity in M1 cocultures. Transcriptome sequencing revealed reduced expression of key cardiac genes such as SCN5A,KCNA5,ATP1A1,and GJA5 in the atrial cardiomyocytes. Meta-analysis of atrial fibrillation patient transcriptomes showed high correlation to the in vitro model. Treatment of the coculture with glucocorticoids showed reversal of phenotypes,including reduced beat irregularity,improved conduction,and reversed RNA expression profiles.ConclusionsThis study establishes a causal relationship between M1 activation and the development of subsequent atrial arrhythmia,documented as irregularity in spontaneous electrical activation in atrial cardiomyocytes cocultured with activated macrophages. Further,beat rate irregularity could be alleviated using glucocorticoids. Overall,these results point at macrophage-mediated inflammation as a potential AF induction mechanism and offer new targets for therapeutic development. The findings strongly support the relevance of the proposed hiPSC-derived coculture model and present it as a first of its kind disease model.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13287-024-03814-0. View Publication

To investigate intestinal health and its potential disruptors in vitro,representative models are required. Human induced pluripotent stem cell (hiPSC)-derived intestinal epithelial cells (IECs) more closely resemble the in vivo intestinal tissue than conventional in vitro models like human colonic adenocarcinoma Caco-2 cells. However,the potential of IECs to study immune-related responses upon external stimuli has not been investigated in detail yet. The aim of the current study was to evaluate immune-related effects of IECs by challenging them with a pro-inflammatory cytokine cocktail. Subsequently,the effects of Lactiplantibacillus plantarum WCFS1 were investigated in unchallenged and challenged IECs. All exposures were compared to Caco-2 cells and in vivo data where possible. Upon the inflammatory challenge,IECs and Caco-2 cells induced a pro-inflammatory response which was strongest in IECs. Heat-killed L. plantarum exerted the strongest effect on immune parameters in the IEC model,while L. plantarum in the stationary growth phase had most pronounced effects on immune-related gene expression in Caco-2 cells. Unfortunately,comparison to in vivo transcriptomics data showed limited similarities,which could be explained by essential differences in the study setups. Altogether,hiPSC-derived IECs show a high potential as a model to study immune-related responses in the intestinal epithelium in vitro.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-024-74802-w. View Publication

IntroductionAccumulating evidence indicates that the increased presence of astrocytes is fundamentally linked to the neurological dysfunctions observed in individuals with Down syndrome (DS). REST (RE1-silencing transcription factor),as a chromatin modifier,regulates 15,450 genes in humans. REST is a key regulatory element that governs astrocyte differentiation,development,and the maintenance of their physiological functions. The downregulation of REST may disrupt the homeostatic balance of astrocytes in DS.MethodsThis study aims to elucidate the role of REST in DS-astrocytes through comprehensive transcriptomic analysis and experimental validation.ResultsTranscriptomic analysis identified that REST-targeted differentially expressed genes (DEGs) in DS astrocytes are enriched in pathways associated with inflammatory response. Notably,our findings in astrocytes derived from DS human induced pluripotent stem cells (hiPSCs) show that the loss of nucleus REST leads to an upregulation of inflammatory mediators and markers indicative of the presence of reactive astrocytes. Lithium treatment,which restored nucleus REST in trisomic astrocytes,significantly suppressed the expression of these inflammatory mediators and reactive astrocyte markers.DiscussionThese findings suggest that REST is pivotal in modulating astrocyte functionality and reactivity in DS. The loss of REST in DS-astrocytes prompts the formation of reactive astrocytes,thereby compromising central nervous system homeostasis. Lithium treatment possesses the potential to rescue astrocyte reactivity in DS by restoring nucleus REST expression. View Publication

The oral mucosa plays an important role in maintaining oral and systemic health by protecting the body from harmful environmental stimuli and pathogens. Current reconstructed human gingiva models (RhG) serve as valuable testing platforms for safety and efficacy testing of dental materials,however they lack important phenotypic characteristics typical of the gingival epithelium. We aimed to determine whether incorporating induced pluripotent stem cells (iPSCs) into the hydrogel of a cell-line RhG (reconstructed epithelium on fibroblast-populated-hydrogel) would improve its phenotype. Immortalized human gingival fibroblasts were resuspended with and without iPSCs in collagen-fibrin hydrogels and gingival keratinocytes were seeded on top of the hydrogels to construct RhGs. RhGs were cultured at air-liquid interface for 1,2,4 and 6 weeks and extensively characterized by immunohistochemistry. In situ hybridization for X and Y chromosomes was conducted to identify female iPSCs and male fibroblasts in the RhGs. iPSC-RhGs showed increased epithelial thickening,rete ridge formation,increased cell proliferation and normalized expression of differentiation markers (keratins,involucrin,loricrin,SKALP/elafin) compared to standard RhGs,resulting in an epithelial phenotype very similar to the native gingiva. An increase in apoptotic cells was detected in iPSC-RhGs after 1 week air-exposed culture,and no iPSCs were detected in the hydrogels after 2 weeks air-exposed culture. The increase in apoptotic iPSCs after 1 week air-exposed culture correlated with an increase in keratinocyte proliferation responsible for the superior phenotype observed at 2 weeks. View Publication

The generation of iPSC-derived hepatocyte-like cells (HLCs) is a powerful tool for studying liver diseases,their therapy as well as drug development. iPSC-derived disease models benefit from their diverse origin of patients,enabling the study of disease-associated mutations and,when considering more than one iPSC line to reflect a more diverse genetic background compared to immortalized cell lines. Unfortunately,the use of iPSC-derived HLCs is limited due to their lack of maturity and a rather fetal phenotype. Commercial kits and complicated 3D-protocols are cost- and time-intensive and hardly useable for smaller working groups. In this study,we optimized our previously published protocol by fine-tuning the initial cell number,exchanging antibiotics and basal medium composition and introducing the small molecule forskolin during the HLC maturation step. We thereby contribute to the liver research field by providing a simple,cost- and time-effective 2D differentiation protocol. We generate functional HLCs with significantly increased HLC hallmark gene (ALB,HNF4?,and CYP3A4) and protein (ALB) expression,as well as significantly elevated inducible CYP3A4 activity. Graphical Abstract 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

Effective therapies for Alzheimer’s disease (AD) remain to be developed. APOE4 is the strongest genetic risk factor for late-onset AD. Pericyte degeneration and blood–brain barrier (BBB) disruption are thought to be early biomarkers of AD and contribute to cognitive decline in APOE4 carriers,representing potential therapeutic targets. Our previous studies have shown that pericyte transplantation is one of the most effective strategies for BBB restoration,exhibiting great therapeutic potential for APOE4-related BBB damage and AD phenotypes. Methods: APOE4/4 mice were treated with pericytes derived from APOE3/3 human induced pluripotent stem cells (hiPSCs). Behavioral tests,AD pathologies,and BBB integrity were assessed. Subsequently,temporal and spatial distribution of the transplanted pericytes was analyzed using tdTomato+ lentivirus labeling. Next,therapeutic effects of apoptotic vesicles (ApoVs) generated from APOE3/3 pericytes were evaluated in APOE4/4 pericytes in vitro. Additionally,transcriptomic and proteomic profiling were performed to identify key effector molecules in pericyte-derived ApoVs. Finally,the therapeutic effects of ApoVs derived from pericytes were evaluated in APOE4/4 mice. Results: Early,multiple transplantations of pericytes derived from APOE3/3 hiPSCs robustly rescued cognitive decline and AD pathologies,restored BBB integrity,and prevented in situ pericyte degeneration in aged APOE4/4 mice. Intriguingly,ApoVs released from the infused cells,rather than the transplanted pericytes,were predominantly distributed in the brain,which were ingested by in situ APOE4/4 pericytes and then promoted functional recovery. We further characterized insulin growth factor-2 (IGF-2) as a key factor in APOE3/3 pericyte-derived ApoVs. Infusion of the in vitro generated ApoVs from APOE3/3 pericytes demonstrated distinct therapeutic effects in APOE4/4 mice,which were reversed by IGF2 knockout. Conclusions: APOE3/3 pericytes or APOE3/3 pericyte-derived IGF2-rich ApoVs may offer promising therapeutic strategies for APOE4-associated AD. View Publication

Proteomics of dystrophic muscle samples is limited by the amount of protein that can be extracted from patient biopsies. Cells and tissues derived from patient-derived induced pluripotent stem cells (iPSCs) can be an expandable alternative source. We have patterned iPSCs from three Duchenne muscular dystrophy (DMD) patient lines into skeletal muscle cells using a two-dimensional as well as our three-dimensional organoid differentiation system. Probes with sufficient protein amounts could be extracted and prepared for mass spectrometry. In total,3007 proteins in 2D and 2709 proteins in 3D were detected in DMD patient probes. A total of 83 proteins in 2D and 338 proteins in 3D can be described as differentially expressed between DMD and control patient probes in a post hoc test. We have identified and we propose Myosin-9,Collagen 18A,Tropomyosin 1,BASP1,RUVBL1,and NCAM1 as proteins specifically altered in their expression in DMD for further investigation. Proteomics of skeletal muscle organoids resulted in greater consistency of results between cell lines in comparison to the two-dimensional myogenic differentiation protocol. View Publication

Chemotherapy-induced peripheral neuropathy (CIPN) affects up to two-thirds of cancer patients undergoing cytotoxic chemotherapy. Here,we used human iPSC-derived sensory neurons (iPSC-DSN) to model CIPN in vitro. Administration of various chemotherapeutic agents (i.e.,paclitaxel,vincristine,bortezomib and cisplatin) at clinically applicable concentrations resulted in reduced cell viability,axonal degeneration,electrophysiological dysfunction and increased levels of phosphorylated c-Jun in iPSC-DSN. Transcriptomic analyses revealed that the upregulation of c-Jun strongly correlated with the expression of genes of neuronal injury,apoptosis and inflammatory signatures. To test whether c-Jun plays a central role in the development of CIPN,we applied the small molecule inhibitor of the Jun N-terminal kinase,SP600125,to iPSC-DSN treated with neurotoxic chemotherapy. c-Jun inhibition prevented chemotherapy-induced neurotoxicity by preserving cell viability,axonal integrity and electrophysiological function of iPSC-DSN. These findings identify c-Jun as a key mediator of CIPN pathophysiology across multiple drug types and present preclinical evidence that c-Jun inhibition is an attractive therapeutic target to prevent CIPN. View Publication