Gradient conducting polymer surfaces with netrin-1-conjugation promote axon guidance and neuron transmission of human iPSC-derived retinal ganglion cells.

Major advances have been made in utilizing human-induced pluripotent stem cells (hiPSCs) for regenerative medicine. Nevertheless, the delivery and integration of hiPSCs into target tissues remain significant challenges, particularly in the context of retinal ganglion cell (RGC) restoration. In this study, we introduce a promising avenue for providing directional guidance to regenerated cells in the retina. First, we developed a technique for construction of gradient interfaces based on functionalized conductive polymers, which could be applied with various functionalized ehthylenedioxythiophene (EDOT) monomers. Using a tree-shaped channel encapsulated with a thin PDMS and a specially designed electrochemical chamber, gradient flow generation could be converted into a functionalized-PEDOT gradient film by cyclic voltammetry. The characteristics of the successfully fabricated gradient flow and surface were analyzed using fluorescent labels, time of flight secondary ion mass spectrometry (TOF-SIMS), and X-ray photoelectron spectroscopy (XPS). Remarkably, hiPSC-RGCs seeded on PEDOT exhibited improvements in neurite outgrowth, axon guidance and neuronal electrophysiology measurements. These results suggest that our novel gradient PEDOT may be used with hiPSC-based technologies as a potential biomedical engineering scaffold for functional restoration of RGCs in retinal degenerative diseases and optic neuropathies.

Templated Pluripotent Stem Cell Differentiation via Substratum-Guided Artificial Signaling.

The emerging field of synthetic morphogenesis implements synthetic biology tools to investigate the minimal cellular processes sufficient for orchestrating key developmental events. As the field continues to grow, there is a need for new tools that enable scientists to uncover nuances in the molecular mechanisms driving cell fate patterning that emerge during morphogenesis. Here, we present a platform that combines cell engineering with biomaterial design to potentiate artificial signaling in pluripotent stem cells (PSCs). This platform, referred to as PSC-MATRIX, extends the use of programmable biomaterials to PSCs competent to activate morphogen production through orthogonal signaling, giving rise to the opportunity to probe developmental events by initiating morphogenetic programs in a spatially constrained manner through non-native signaling channels. We show that the PSC-MATRIX platform enables temporal and spatial control of transgene expression in response to bulk, soluble inputs in synthetic Notch (synNotch)-engineered human PSCs for an extended culture of up to 11 days. Furthermore, we used PSC-MATRIX to regulate multiple differentiation events via material-mediated artificial signaling in engineered PSCs using the orthogonal ligand green fluorescent protein, highlighting the potential of this platform for probing and guiding fate acquisition. Overall, this platform offers a synthetic approach to interrogate the molecular mechanisms driving PSC differentiation that could be applied to a variety of differentiation protocols.

A human organoid drug screen identifies α2-adrenergic receptor signaling as a therapeutic target for cartilage regeneration.

Directed differentiation of stem cells toward chondrogenesis in vitro and in situ to regenerate cartilage suffers from off-target differentiation and hypertrophic tendency. Here, we generated a cartilaginous organoid system from human expanded pluripotent stem cells (hEPSCs) carrying a COL2A1mCherry and COL10A1eGFP double reporter, enabling real-time monitoring of chondrogenesis and hypertrophy. After screening 2,040 FDA-approved drugs, we found that α-adrenergic receptor (α-AR) antagonists, especially phentolamine, stimulated chondrogenesis but repressed hypertrophy, while α2-AR agonists reduced chondrogenesis and induced hypertrophy. Phentolamine prevented cartilage degeneration in hEPSC cartilaginous organoid and human cartilage explant models and stimulated microfracture-activated endogenous skeletal stem cells toward hyaline-like cartilage regeneration without fibrotic degeneration in situ. Mechanistically, α2-AR signaling induced hypertrophic degeneration via cyclic guanosine monophosphate (cGMP)-dependent secretory leukocyte protease inhibitor (SLPI) production. SLPI-deleted cartilaginous organoid was degeneration resistant, facilitating large cartilage defect healing. Ultimately, targeting α2-AR/SLPI was a promising and clinically feasible strategy to regenerate cartilage via promoting chondrogenesis and repressing hypertrophy.

Detection of Residual iPSCs Following Differentiation of iPSC-Derived Retinal Pigment Epithelial Cells.

Purpose: The goal of this study was to develop a lot release assay for iPSC residuals following directed differentiation of iPSCs to retinal pigment epithelial (RPE) cells. Methods: RNA Sequencing (RNA Seq) of iPSCs and RPE derived from them was used to identify pluripotency markers downregulated in RPE cells. Quantitative real time PCR (qPCR) was then applied to assess iPSC residuals in iPSC-derived RPE. The limit of detection (LOD) of the assay was determined by performing spike-in assays with known quantities of iPSCs serially diluted into an RPE suspension. Results: ZSCAN10 and LIN28A were among 8 pluripotency markers identified by RNA Seq as downregulated in RPE. Based on copy number and expression of pseudogenes and lncRNAs ZSCAN10 and LIN28A were chosen for use in qPCR assays for residual iPSCs. Reverse transcription PCR indicated generally uniform expression of ZSCAN10 and LIN28A in 21 clones derived from 8 iPSC donors with no expression of either in RPE cells derived from 5 donor lines. Based on qPCR, ZSCAN10, and LIN28A expression in iPSCs was generally uniform. The LOD for ZSCAN10 and LIN28A in qPCR assays was determined using spike in assays of RPE derived from 2 iPSC lines. Analysis of ΔΔCt found the limit of detection to be <0.01% of cells, equivalent to <1 iPSC/10,000 RPE cells in both iPSC lines. Conclusions: qPCR for ZSCAN10 and LIN28A detects <1 in 10,000 residual iPSCs in a population of iPSC-derived RPE providing an adequate LOD of iPSC residuals for lot release testing.

Enhanced spinal cord repair using bioengineered induced pluripotent stem cell-derived exosomes loaded with miRNA.

BACKGROUND: A spinal cord injury (SCI) can result in severe impairment and fatality as well as significant motor and sensory abnormalities. Exosomes produced from IPSCs have demonstrated therapeutic promise for accelerating spinal cord injury recovery, according to a recent study. OBJECTIVE: This study aims to develop engineered IPSCs-derived exosomes (iPSCs-Exo) capable of targeting and supporting neurons, and to assess their therapeutic potential in accelerating recovery from spinal cord injury (SCI). METHODS: iPSCs-Exo were characterized using Transmission Electron Microscopy (TEM), Nanoparticle Tracking Analysis (NTA), and western blot. To enhance neuronal targeting, iPSCs-Exo were bioengineered, and their uptake by neurons was visualized using PKH26 labeling and fluorescence microscopy. In vitro, the anti-inflammatory effects of miRNA-loaded engineered iPSCs-Exo were evaluated by exposing neurons to LPS and IFN-γ. In vivo, biodistribution of engineered iPSC-Exo was monitored using a vivo imaging system. The therapeutic efficacy of miRNA-loaded engineered iPSC-Exo in a SCI mouse model was assessed by Basso Mouse Scale (BMS) scores, H&E, and Luxol Fast Blue (LFB) staining. RESULTS: The results showed that engineered iPSC-Exo loaded with miRNA promoted the spinal cord injure recovery. Thorough safety assessments using H&E staining on major organs revealed no evidence of systemic toxicity, with normal organ histology and biochemistry profiles following engineered iPSC-Exo administration. CONCLUSION: These results suggest that modified iPSC-derived exosomes loaded with miRNA have great potential as a cutting-edge therapeutic approach to improve spinal cord injury recovery. The observed negligible systemic toxicity further underscores their potential safety and efficacy in clinical applications.

TNFα prevents FGF4-mediated rescue of astrocyte dysfunction and reactivity in human ALS models.

Astrocytes play a crucial role in the onset and progression of amyotrophic lateral sclerosis (ALS), a fatal disorder marked by the degeneration of motor neurons (MNs) in the central nervous system. Although astrocytes in ALS are known to be toxic to MNs, the pathological changes leading to their neurotoxic phenotype remain poorly understood. In this study, we generated human astrocytes from induced pluripotent stem cells (iPSCs) carrying the ALS-associated A4V mutation in superoxide dismutase 1 (SOD1) to examine early cellular pathways and network changes. Proteomic analysis revealed that ALS astrocytes are both dysfunctional and reactive compared to control astrocytes. We identified significant alterations in the levels of proteins linked to ALS pathology and the innate immune cGAS-STING pathway. Furthermore, we found that ALS astrocyte reactivity differs from that of control astrocytes treated with tumor necrosis factor alpha (TNFα), a key cytokine in inflammatory reactions. We then evaluated the potential of fibroblast growth factor (FGF) 2, 4, 16, and 18 to reverse ALS astrocyte phenotype. Among these, FGF4 successfully reversed ALS astrocyte dysfunction and reactivity in vitro. When delivered to the spinal cord of the SOD1G93A mouse model of ALS, FGF4 lowered astrocyte reactivity. However, this was not sufficient to protect MNs from cell death. Further analysis indicated that TNFα abrogated the reactivity reduction achieved by FGF4, suggesting that complete rescue of the ALS phenotype by FGF4 is hindered by ongoing complex neuroinflammatory processes in vivo. In summary, our data demonstrate that astrocytes generated from ALS iPSCs are inherently dysfunctional and exhibit an immune reactive phenotype. Effectively targeting astrocyte dysfunction and reactivity in vivo may help mitigate ALS and prevent MN death.

Saxitoxin potentiates human neuronal cell death induced by Zika virus while sparing neural progenitors and astrocytes.

The Zika virus (ZIKV) epidemic declared in Brazil between 2015 and 2016 was associated with an increased prevalence of severe congenital malformations, including microcephaly. The distribution of microcephaly cases was not uniform across the country, with a disproportionately higher incidence in the Northeast region (NE). Our previous work demonstrated that saxitoxin (STX), a toxin present in the drinking water reservoirs of the NE, exacerbated the damaging effects of ZIKV on the developing brain. We hypothesized that the impact of STX might vary among different neural cell types. While ZIKV infection caused severe damages on astrocytes and neural stem cells (NSCs), the addition of STX did not exacerbate these effects. We observed that neurons subjected to STX exposure were more prone to apoptosis and displayed higher ZIKV infection rate. These findings suggest that STX exacerbates the harmful effects of ZIKV on neurons, thereby providing a plausible explanation for the heightened severity of ZIKV-induced congenital malformations observed in Brazil's NE. This study highlights the importance of understanding the interactive effects of environmental toxins and infectious pathogens on neural development, with potential implications for public health policies.

Global Knowledge Map and Emerging Research Trends in Induced Pluripotent Stem Cells and Hereditary Diseases: A CiteSpace-based Visualization and Analysis.

The rise of induced pluripotent stem cells (iPSCs) technology has ushered in a landmark shift in the study of hereditary diseases. However, there is a scarcity of reports that offer a comprehensive and objective overview of the current state of research at the intersection of iPSCs and hereditary diseases. Therefore, this study endeavors to categorize and synthesize the publications in this field over the past decade through bibliometric methods and visual knowledge mapping, aiming to visually analyze their research focus and clinical trends. The English language literature on iPSCs and hereditary diseases, published from 2014 to 2023 in the Web of Science Core Collection (WoSCC), was examined. The CiteSpace (version 6.3.R1) software was utilized to visualize and analyze country/region, institution, scholar, co-cited authors, and co-cited journals. Additionally, the co-occurrence, clustering, and bursting of co-cited references were displayed. Analysis of 347 articles that met the inclusion criteria revealed a steady increase in the number of published articles and citation frequency in the field over the past decade. With regard to the countries/regions, institutions, scholars, and journals where the articles were published, the highest numbers were found in the USA, the University of California System, Suren M. Zakian, and Stem Cell Research, respectively. The current research is focused on the construction of disease models, both before and after correction, as well as drug target testing for single-gene hereditary diseases. Chromosome transplantation genomic therapy for hereditary diseases with abnormal chromosome structures may emerge as a future research hotspot in this field.

Homology-independent targeted insertion-mediated derivation of M1-biased macrophages harbouring Megf10 and CD3ζ from human pluripotent stem cells.

BACKGROUND: Macrophages engineered with chimeric antigen receptors (CAR) are suitable for immunotherapy based on their immunomodulatory activity and ability to infiltrate solid tumours. However, the production and application of genetically edited, highly effective, and mass-produced CAR-modified macrophages (CAR-Ms) are challenging. METHODS: Here, we used homology-independent targeted insertion (HITI) for site-directed CAR integration into the safe-harbour region of human pluripotent stem cells (hPSCs). This approach, together with a simple differentiation protocol, produced stable and highly effective CAR-Ms without heterogeneity. FINDINGS: These engineered cells phagocytosed cancer cells, leading to significant inhibition of cancer-cell proliferation in vitro and in vivo. Furthermore, the engineered CARs, which incorporated a combination of CD3ζ and Megf10 (referred to as FRP5Mζ), markedly enhanced the antitumour effect of CAR-Ms by promoting M1, but not M2, polarisation. FRP5Mζ promoted M1 polarisation via nuclear factor kappa B (NF-κB), ERK, and STAT1 signalling, and concurrently inhibited STAT3 signalling even under M2 conditions. These features of CAR-Ms modulated the tumour microenvironment by activating inflammatory signalling, inducing M1 polarisation of bystander non-CAR macrophages, and enhancing the infiltration of T cells in cancer spheroids. INTERPRETATION: Our findings suggest that CAR-Ms have promise as immunotherapeutics. In conclusion, the guided insertion of CAR containing CD3ζ and Megf10 domains is an effective strategy for the immunotherapy of solid tumours. FUNDING: This work was supported by KRIBB Research Initiative Program Grant (KGM4562431, KGM5282423) and a Korean Fund for Regenerative Medicine (KFRM) grant funded by the Korean government (Ministry of Science and ICT,Ministry of Health and Welfare) (22A0304L1-01).

Disease models of Leigh syndrome: From yeast to organoids.

Leigh syndrome (LS) is a severe mitochondrial disease that results from mutations in the nuclear or mitochondrial DNA that impairs cellular respiration and ATP production. Mutations in more than 100 genes have been demonstrated to cause LS. The disease most commonly affects brain development and function, resulting in cognitive and motor impairment. The underlying pathogenesis is challenging to ascertain due to the diverse range of symptoms exhibited by affected individuals and the variability in prognosis. To understand the disease mechanisms of different LS-causing mutations and to find a suitable treatment, several different model systems have been developed over the last 30 years. This review summarizes the established disease models of LS and their key findings. Smaller organisms such as yeast have been used to study the biochemical properties of causative mutations. Drosophila melanogaster, Danio rerio, and Caenorhabditis elegans have been used to dissect the pathophysiology of the neurological and motor symptoms of LS. Mammalian models, including the widely used Ndufs4 knockout mouse model of complex I deficiency, have been used to study the developmental, cognitive, and motor functions associated with the disease. Finally, cellular models of LS range from immortalized cell lines and trans-mitochondrial cybrids to more recent model systems such as patient-derived induced pluripotent stem cells (iPSCs). In particular, iPSCs now allow studying the effects of LS mutations in specialized human cells, including neurons, cardiomyocytes, and even three-dimensional organoids. These latter models open the possibility of developing high-throughput drug screens and personalized treatments based on defined disease characteristics captured in the context of a defined cell type. By analyzing all these different model systems, this review aims to provide an overview of past and present means to elucidate the complex pathology of LS. We conclude that each approach is valid for answering specific research questions regarding LS, and that their complementary use could be instrumental in finding treatment solutions for this severe and currently untreatable disease.

Transplantation of human pluripotent stem cell-derived retinal sheet in a primate model of macular hole.

Macular hole (MH) is a retinal break involving the fovea that causes impaired vision. Although advances in vitreoretinal surgical techniques achieve >90% MH closure rate, refractory cases still exist. For such cases, autologous retinal transplantation is an optional therapy showing good anatomic success, but visual improvement is limited and peripheral visual field defects are inevitable after graft harvesting. Here, using a non-human primate model, we evaluated whether human embryonic stem cell-derived retinal organoid (RO) sheet transplantation can be an effective option for treating MH. After transplantation, MH was successfully closed by continuous filling of the MH space with the RO sheet, resulting in improved visual function, although no host-graft synaptic connections were confirmed. Mild xeno-transplantation rejection was controlled by additional focal steroid injections and rod/cone photoreceptors developed in the graft. Overall, our findings suggest pluripotent stem cell-derived RO sheet transplantation as a practical option for refractory MH treatment.

Mutations in fibronectin dysregulate chondrogenesis in skeletal dysplasia.

Fibronectin (FN) is an extracellular matrix glycoprotein essential for the development and function of major vertebrate organ systems. Mutations in FN result in an autosomal dominant skeletal dysplasia termed corner fracture-type spondylometaphyseal dysplasia (SMDCF). The precise pathomechanisms through which mutant FN induces impaired skeletal development remain elusive. Here, we have generated patient-derived induced pluripotent stem cells as a cell culture model for SMDCF to investigate the consequences of FN mutations on mesenchymal stem cells (MSCs) and their differentiation into cartilage-producing chondrocytes. In line with our previous data, FN mutations disrupted protein secretion from MSCs, causing a notable increase in intracellular FN and a significant decrease in extracellular FN levels. Analyses of plasma samples from SMDCF patients also showed reduced FN in circulation. FN and endoplasmic reticulum (ER) protein folding chaperones (BIP, HSP47) accumulated in MSCs within ribosome-covered cytosolic vesicles that emerged from the ER. Massive amounts of these vesicles were not cleared from the cytosol, and a smaller subset showed the presence of lysosomal markers. The accumulation of intracellular FN and ER proteins elevated cellular stress markers and altered mitochondrial structure. Bulk RNA sequencing revealed a specific transcriptomic dysregulation of the patient-derived cells relative to controls. Analysis of MSC differentiation into chondrocytes showed impaired mesenchymal condensation, reduced chondrogenic markers, and compromised cell proliferation in mutant cells. Moreover, FN mutant cells exhibited significantly lower transforming growth factor beta-1 (TGFß1) expression, crucial for mesenchymal condensation. Exogenous FN or TGFß1 supplementation effectively improved the MSC condensation and promoted chondrogenesis in FN mutant cells. These findings demonstrate the cellular consequences of FN mutations in SMDCF and explain the molecular pathways involved in the associated altered chondrogenesis.

Automated CRISPR/Cas9-based genome editing of human pluripotent stem cells using the StemCellFactory.

CRISPR/Cas9 genome editing is a rapidly advancing technology that has the potential to accelerate research and development in a variety of fields. However, manual genome editing processes suffer from limitations in scalability, efficiency, and standardization. The implementation of automated systems for genome editing addresses these challenges, allowing researchers to cover the increasing need and perform large-scale studies for disease modeling, drug development, and personalized medicine. In this study, we developed an automated CRISPR/Cas9-based genome editing process on the StemCellFactory platform. We implemented a 4D-Nucleofector with a 96-well shuttle device into the StemCellFactory, optimized several parameters for single cell culturing and established an automated workflow for CRISPR/Cas9-based genome editing. When validated with a variety of genetic backgrounds and target genes, the automated workflow showed genome editing efficiencies similar to manual methods, with indel rates of up to 98%. Monoclonal colony growth was achieved and monitored using the StemCellFactory-integrated CellCelector, which allowed the exclusion of colonies derived from multiple cells or growing too close to neighbouring colonies. In summary, we demonstrate the successful establishment of an automated CRISPR/Cas9-based genome editing process on the StemCellFactory platform. The development of such a standardized and scalable automated CRISPR/Cas9 system represents an exciting new tool in genome editing, enhancing our ability to address a wide range of scientific questions in disease modeling, drug development and personalized medicine.

Early human development and stem cell-based human embryo models.

The use of stem cells to model the early human embryo promises to transform our understanding of developmental biology and human reproduction. In this review, we present our current knowledge of the first 2 weeks of human embryo development. We first focus on the distinct cell lineages of the embryo and the derivation of stem cell lines. We then discuss the intercellular crosstalk that guides early embryo development and how this crosstalk is recapitulated in vitro to generate stem cell-based embryo models. We highlight advances in this fast-developing field, discuss current limitations, and provide a vision for the future.

Defining Cardiomyocyte Repolarization Response to Pharmacotherapy in Long-QT Syndrome Type 3.

BACKGROUND: Long-QT syndrome is a primary cardiac ion channelopathy predisposing a patient to ventricular arrhythmia through delayed repolarization on the resting ECG. We aimed to establish a patient-specific, human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes model of long-QT syndrome type 3 (LQT3) using clustered regularly interspaced palindromic repeats (CRISPR/Cas9), for disease modeling and drug challenge. METHODS AND RESULTS: HiPSCs were generated from a patient with LQT3 harboring an SCN5A pathogenic variant (c.1231G>A; p.Val411Met), and an unrelated healthy control. The same SCN5A pathogenic variant was engineered into the background healthy control hiPSCs via CRISPR/Cas9 gene editing to generate a second disease model of LQT3 for comparison with an isogenic control. All 3 hiPSC lines were differentiated into cardiomyocytes. Both the patient-derived LQT3 (SCN5A+/-) and genetically engineered LQT3 (SCN5A+/-) hiPSC-derived cardiomyocytes showed significantly prolonged cardiomyocyte repolarization compared with the healthy control. Mexiletine, a cardiac voltage-gated sodium channel (NaV1.5) blocker, shortened repolarization in both patient-derived LQT3 and genetically engineered LQT3 hiPSC-derived cardiomyocytes, but had no effect in the control. Notably, calcium channel blockers nifedipine and verapamil showed a dose-dependent shortening of repolarization, rescuing the phenotype. Additionally, therapeutic drugs known to prolong the corrected QT in humans (ondansetron, clarithromycin, and sotalol) demonstrated this effect in vitro, but the LQT3 clones were not more disproportionately affected compared with the control. CONCLUSIONS: We demonstrated that patient-derived and genetically engineered LQT3 hiPSC-derived cardiomyocytes faithfully recapitulate pathologic characteristics of LQT3. The clinical significance of such an in vitro model is in the exploration of novel therapeutic strategies, stratifying drug adverse reaction risk and potentially facilitating a more targeted, patient-specific approach in high-risk patients with LQT3.

Skin organoid transplantation promotes tissue repair with scarless in frostbite.

Frostbite is the most common cold injury and is caused by both immediate cold-induced cell death and the gradual development of localized inflammation and tissue ischemia. Delayed healing of frostbite often leads to scar formation, which not only causes psychological distress but also tends to result in the development of secondary malignant tumors. Therefore, a rapid healing method for frostbite wounds is urgently needed. Herein, we used a mouse skin model of frostbite injury to evaluate the recovery process after frostbite. Moreover, single-cell transcriptomics was used to determine the patterns of changes in monocytes, macrophages, epidermal cells and fibroblasts during frostbite. Most importantly, human-induced pluripotent stem cell (hiPSC) -derived skin organoids combining with gelatin-hydrogel were constructed for the treatment of frostbite. The results showed that skin organoid treatment significantly accelerated wound healing by reducing early inflammation after frostbite and increasing the proportions of epidermal stem cells. Moreover, in the later stage of wound healing, skin organoids reduced the overall proportions of fibroblasts, significantly reduced fibroblast-to-myofibroblast transition by regulating the integrin α5ß1-FAK pathway, and remodeled the extracellular matrix (ECM) through degradation and reassembly mechanisms, facilitating the restoration of physiological ECM and reducing the abundance of ECM associated with abnormal scar formation. These results highlight the potential application of organoids for promoting the reversal of frostbite-related injury and the recovery of skin functions. This study provides a new therapeutic alternative for patients suffering from disfigurement and skin dysfunction caused by frostbite.

Comparison of human pluripotent stem cell differentiation protocols to generate neuroblastoma tumors.

Neuroblastoma is the most common pediatric extracranial solid tumor and is derived from trunk neural crest cells (tNCC) and its progenitor sympathoadrenal (SA) cells. While human pluripotent stem cell (PSC) models of neuroblastoma have been described, the PSC were differentiated using protocols that made neural crest cells, but not specifically the trunk subtype. Here, we compared four recent protocols to differentiate pluripotent stem cells (PSC) toward SA cells and examined their efficiency at generating SA cells along with earlier cell states (neuromesodermal progenitors [NMP], tNCC), as well as generating MYCN-driven tumors. Interestingly, the protocols that created cells with the highest level of NMP markers did not produce cells with the highest tNCC or SA cell markers. We identified a protocol that consistently produced cells with the highest level of SA markers using two PSC lines of different genders. This protocol also generated tumors with the highest level of PHOX2B, a marker of neuroblastoma. Transcriptionally, however, each protocol generates tumors that resemble neuroblastoma. Two of the protocols repeatedly produced adrenergic neuroblastoma whereas the other two protocols were ambiguous. Thus, we identified a protocol that reliably generates adrenergic neuroblastoma.

Environmental Cues Facilitate Maturation and Patterning of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes.

BACKGROUND/AIMS: Advances in induced pluripotent stem cell (iPSC) technology allow for reprogramming of adult somatic cells into stem cells from which patient- and disease-specific cardiomyocytes (CMs) can be derived. Yet, the potential of iPSC technology to revolutionize cardiovascular research is limited, in part, by the embryonic nature of these cells. Here, we test the hypothesis that decellularized porcine left ventricular extracellular cardiac matrix (ECM) provides environmental cues that promote transcriptional maturation and patterning of iPSC-CMs in culture. METHODS: Cardiac progenitor cells were plated on ECM or standard tissue plates (2D monolayer) for 30 days, after which CM orientation and single cell transcriptomics were evaluated using confocal imaging and singe cell RNA-sequencing, respectively. RESULTS: Cardiac progenitors differentiated on left ventricular ECM formed longitudinal fibers that differed quantitatively from progenitors differentiated in standard 2D conditions. Unsupervised clustering of single cell transcriptomics identified a CM cluster expressing a higher level of genes related to CM maturation. CMs differentiated on ECM were overrepresented in this cluster, indicating a bias toward CM maturation, compared to cells differentiated in standard 2D monolayer conditions. CONCLUSION: Our data suggest that environmental cues related to the left ventricular ECM may promote differentiation to a more mature CM state compared to cells differentiated on a standard 2D monolayer, while facilitating organization into longitudinal micro-fibers. Our study highlights the utility of ECM as a differentiation substrate to promote CM maturation and fiber orientation in vitro .

Development of a TBXT-EGFP iPS Cell Model for Screening the Early Developmental Toxicity of Typical Environmental Pollutants.

In our daily lives, we are inevitably exposed to a variety of environmental pollutants in numerous ways. Fortunately, recent years have witnessed significant advancements in the field of stem cell toxicology, which have provided new opportunities for research in environmental toxicology. Applying stem cell technology to environmental toxicology, overcomes some of the limitations of traditional screening methods and we can more accurately predict the toxicity of environmental pollutants. However, there are still several aspects of stem cell toxicology models that require improvement, such as increasing the throughput of detection and simplifying detection methods. Consequently, we developed an environmental pollutant toxicity detection model based on TBXT-EGFP iPS cells and screened the developmental toxicity of 38 typical environmental pollutants. Our results indicate that TBBPA-BDBPE, TBBPA-BHEE, DG, and AO2246 may interfere with the expression of TBXT, a critical marker gene for early human embryo development, implying that these environmental pollutants could lead to developmental abnormalities.